Yuval Tassa
2810edd27a
PiperOrigin-RevId: 919020039 Change-Id: I441295c0baa0b7456f78239fbd5478d32ffc07c1
4054 lines
115 KiB
C++
4054 lines
115 KiB
C++
// Copyright 2021 DeepMind Technologies Limited
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Tests for engine/engine_forward.c.
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#include "src/engine/engine_forward.h"
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#include "src/engine/engine_derivative.h"
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#include <algorithm>
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#include <array>
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#include <cmath>
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#include <cstdlib>
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#include <limits>
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#include <vector>
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#include <string>
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#include <gmock/gmock.h>
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#include <gtest/gtest.h>
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#include <mujoco/mjmodel.h>
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#include <mujoco/mjtype.h>
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#include <mujoco/mujoco.h>
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#include <mujoco/mjxmacro.h>
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#include "src/cc/array_safety.h"
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#include "src/engine/engine_callback.h"
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#include "src/engine/engine_core_util.h"
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#include "src/engine/engine_io.h"
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#include "test/fixture.h"
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#ifdef MEMORY_SANITIZER
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#include <sanitizer/msan_interface.h>
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#endif
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namespace mujoco {
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namespace {
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static const char* const kEnergyConservingPendulumPath =
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"engine/testdata/derivative/energy_conserving_pendulum.xml";
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// helper for precision-aware checks in macros (e.g. MJDATA_POINTERS)
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template <typename T>
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void ExpectNear(T a, T b) {
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EXPECT_EQ(a, b);
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}
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template <>
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void ExpectNear<mjtNum>(mjtNum a, mjtNum b) {
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EXPECT_EQ(a, b);
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}
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static const char* const kDampedActuatorsPath =
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"engine/testdata/derivative/damped_actuators.xml";
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static const char* const kJointForceClamp =
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"engine/testdata/actuation/joint_force_clamp.xml";
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static const char* const kTendonForceClamp =
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"engine/testdata/actuation/tendon_force_clamp.xml";
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using ::testing::Pointwise;
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using ::testing::Ne;
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using ::testing::HasSubstr;
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using ::testing::NotNull;
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using ::testing::Gt;
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// --------------------------- activation limits -------------------------------
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struct ActLimitedTestCase {
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std::string test_name;
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mjtIntegrator integrator;
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};
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using ParametrizedForwardTest = ::testing::TestWithParam<ActLimitedTestCase>;
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TEST_P(ParametrizedForwardTest, ActLimited) {
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static constexpr char xml[] = R"(
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<mujoco>
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<option timestep="0.01"/>
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<worldbody>
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<body>
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<joint name="slide" type="slide" axis="1 0 0"/>
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<geom size=".1"/>
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</body>
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</worldbody>
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<actuator>
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<general joint="slide" gainprm="100" biasprm="0 -100" biastype="affine"
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dynprm="10" dyntype="integrator"
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actlimited="true" actrange="-1 1"/>
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</actuator>
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</mujoco>
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)";
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char error[1024];
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mjModel* model = LoadModelFromString(xml, error, sizeof(error));
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ASSERT_THAT(model, NotNull()) << error;
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mjData* data = mj_makeData(model);
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model->opt.integrator = GetParam().integrator;
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data->ctrl[0] = 1.0;
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// integrating up from 0, we will hit the clamp after 99 steps
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for (int i=0; i < 200; i++) {
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mj_step(model, data);
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// always greater than lower bound
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EXPECT_GT(data->act[0], -1);
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// after 99 steps we hit the upper bound
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if (i < 99) EXPECT_LT(data->act[0], 1);
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if (i >= 99) EXPECT_NEAR(data->act[0], 1, MjTol(0, 5e-6));
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}
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data->ctrl[0] = -1.0;
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// integrating down from 1, we will hit the clamp after 199 steps
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for (int i=0; i < 300; i++) {
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mj_step(model, data);
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// always smaller than upper bound
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EXPECT_LT(data->act[0], model->actuator_actrange[1]);
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// after 199 steps we hit the lower bound
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if (i < 199) EXPECT_GT(data->act[0], model->actuator_actrange[0]);
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if (i >= 199) {
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EXPECT_NEAR(data->act[0], model->actuator_actrange[0], MjTol(0.0, 5e-6));
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}
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}
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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INSTANTIATE_TEST_SUITE_P(
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ParametrizedForwardTest, ParametrizedForwardTest,
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testing::ValuesIn<ActLimitedTestCase>({
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{"Euler", mjINT_EULER},
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{"Implicit", mjINT_IMPLICIT},
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{"RK4", mjINT_RK4},
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}),
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[](const testing::TestParamInfo<ParametrizedForwardTest::ParamType>& info) {
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return info.param.test_name;
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});
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// --------------------------- damping actuator --------------------------------
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using ForwardTest = MujocoTest;
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TEST_F(ForwardTest, DamperDampens) {
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static constexpr char xml[] = R"(
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<mujoco>
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<worldbody>
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<body>
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<geom size="1"/>
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<joint name="jnt" type="slide" axis="1 0 0"/>
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</body>
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</worldbody>
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<actuator>
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<motor joint="jnt"/>
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<damper joint="jnt" kv="1000" ctrlrange="0 100"/>
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</actuator>
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</mujoco>
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)";
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char error[1024];
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mjModel* model = LoadModelFromString(xml, error, sizeof(error));
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ASSERT_THAT(model, NotNull()) << error;
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mjData* data = mj_makeData(model);
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// move the joint
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data->ctrl[0] = 100.0;
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data->ctrl[1] = 0.0;
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for (int i=0; i < 100; i++)
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mj_step(model, data);
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// stop the joint with damping
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data->ctrl[0] = 0.0;
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data->ctrl[1] = 100.0;
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for (int i=0; i < 1000; i++)
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mj_step(model, data);
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EXPECT_LE(data->qvel[0], std::numeric_limits<double>::epsilon());
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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static const char* const kArmatureEquivalencePath =
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"engine/testdata/armature_equivalence.xml";
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// test that adding joint armature is equivalent to a coupled rotating mass with
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// a gear ratio enforced by an equality
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TEST_F(ForwardTest, ArmatureEquivalence) {
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const std::string xml_path = GetTestDataFilePath(kArmatureEquivalencePath);
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char error[1000];
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mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, error, sizeof(error));
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ASSERT_THAT(model, NotNull()) << error;
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mjData* data = mj_makeData(model);
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// with actuators
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mjtNum qpos_mse = 0;
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int nstep = 0;
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while (data->time < 4) {
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data->ctrl[0] = data->ctrl[1] = mju_sin(2*data->time);
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mj_step(model, data);
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nstep++;
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mjtNum err = data->qpos[0] - data->qpos[2];
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qpos_mse += err * err;
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}
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EXPECT_LT(mju_sqrt(qpos_mse/nstep), 1e-3);
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// no actuators
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model->opt.disableflags |= mjDSBL_ACTUATION;
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qpos_mse = 0;
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nstep = 0;
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mj_resetData(model, data);
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while (data->time < 4) {
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mj_step(model, data);
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nstep++;
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mjtNum err = data->qpos[0] - data->qpos[2];
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qpos_mse += err * err;
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}
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EXPECT_LT(mju_sqrt(qpos_mse/nstep), 1e-3);
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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// --------------------------- implicit integrator -----------------------------
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using ImplicitIntegratorTest = MujocoTest;
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// Disabling implicit joint damping works as expected
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TEST_F(ImplicitIntegratorTest, EulerDampDisable) {
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static constexpr char xml[] = R"(
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<mujoco>
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<option>
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<flag eulerdamp="disable"/>
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</option>
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<worldbody>
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<body>
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<joint axis="1 0 0" damping="2"/>
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<geom type="capsule" size=".01" fromto="0 0 0 0 .1 0"/>
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<body pos="0 .1 0">
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<joint axis="0 1 0" damping="1"/>
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<geom type="capsule" size=".01" fromto="0 0 0 .1 0 0"/>
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</body>
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</body>
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</worldbody>
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</mujoco>
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)";
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char error[1024];
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mjModel* model = LoadModelFromString(xml, error, sizeof(error));
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ASSERT_THAT(model, NotNull()) << error;
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mjData* data = mj_makeData(model);
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// step once, call mj_forward, save qvel and qacc
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mj_step(model, data);
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mj_forward(model, data);
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std::vector<mjtNum> qvel = AsVector(data->qvel, model->nv);
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std::vector<mjtNum> qacc = AsVector(data->qacc, model->nv);
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// second step
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mj_step(model, data);
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// compute finite-difference acceleration
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std::vector<mjtNum> qacc_fd(model->nv);
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for (int i=0; i < model->nv; i++) {
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qacc_fd[i] = (data->qvel[i] - qvel[i]) / model->opt.timestep;
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}
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// expect finite-differenced qacc to match to high precision
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EXPECT_THAT(qacc_fd, Pointwise(MjNear(1e-14, 1e-6), qacc));
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// reach the same initial state
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mj_resetData(model, data);
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mj_step(model, data);
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// second step again, but with implicit integration of joint damping
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model->opt.disableflags &= ~mjDSBL_EULERDAMP;
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mj_step(model, data);
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// compute finite-difference acceleration difference
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std::vector<mjtNum> dqacc(model->nv);
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for (int i=0; i < model->nv; i++) {
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dqacc[i] = (data->qvel[i] - qvel[i]) / model->opt.timestep;
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}
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// expect finite-differenced qacc to not match
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EXPECT_GT(mju_norm(dqacc.data(), model->nv), 1);
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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// Reducing timesteps reduces the difference between implicit/explicit
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TEST_F(ImplicitIntegratorTest, EulerDampLimit) {
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static constexpr char xml[] = R"(
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<mujoco>
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<worldbody>
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<body>
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<joint axis="1 0 0" damping="2"/>
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<geom type="capsule" size=".01" fromto="0 0 0 0 .1 0"/>
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<body pos="0 .1 0">
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<joint axis="0 1 0" damping="1"/>
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<geom type="capsule" size=".01" fromto="0 0 0 .1 0 0"/>
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</body>
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</body>
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</worldbody>
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</mujoco>
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)";
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char error[1024];
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mjModel* model = LoadModelFromString(xml, error, sizeof(error));
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ASSERT_THAT(model, NotNull()) << error;
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mjData* data = mj_makeData(model);
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mjtNum diff_norm_prev = -1;
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for (const mjtNum dt : {1e-2, 1e-3, 1e-4, 1e-5, 1e-6, 1e-7, 1e-8}) {
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// set timestep
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model->opt.timestep = dt;
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// step twice with implicit damping, save qvel
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model->opt.disableflags &= ~mjDSBL_EULERDAMP;
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mj_resetData(model, data);
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mj_step(model, data);
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mj_step(model, data);
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std::vector<mjtNum> qvel_imp = AsVector(data->qvel, model->nv);
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// step once, step again without implicit damping, save qvel
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mj_resetData(model, data);
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mj_step(model, data);
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model->opt.disableflags |= mjDSBL_EULERDAMP;
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mj_step(model, data);
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std::vector<mjtNum> qvel_exp = AsVector(data->qvel, model->nv);
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mjtNum diff_norm = 0;
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for (int i=0; i < model->nv; i++) {
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diff_norm += (qvel_imp[i] - qvel_exp[i]) * (qvel_imp[i] - qvel_exp[i]);
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}
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diff_norm = mju_sqrt(diff_norm);
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if (diff_norm_prev != -1){
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EXPECT_LT(diff_norm, diff_norm_prev);
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}
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diff_norm_prev = diff_norm;
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}
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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// Euler and implicit should be equivalent if there is only joint damping
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TEST_F(ImplicitIntegratorTest, EulerImplicitEquivalent) {
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static constexpr char xml[] = R"(
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<mujoco>
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<worldbody>
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<body>
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<joint axis="1 0 0" damping="2"/>
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<geom type="capsule" size=".01" fromto="0 0 0 0 .1 0"/>
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<body pos="0 .1 0">
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<joint axis="0 1 0" damping="1"/>
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<geom type="capsule" size=".01" fromto="0 0 0 .1 0 0"/>
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</body>
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</body>
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</worldbody>
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</mujoco>
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)";
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char error[1024];
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mjModel* model = LoadModelFromString(xml, error, sizeof(error));
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ASSERT_THAT(model, NotNull()) << error;
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mjData* data = mj_makeData(model);
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// step 10 times with Euler, save copy of qpos as vector
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for (int i=0; i < 10; i++) {
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mj_step(model, data);
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}
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std::vector<mjtNum> qposEuler = AsVector(data->qpos, model->nq);
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// reset, step 10 times with implicit
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mj_resetData(model, data);
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model->opt.integrator = mjINT_IMPLICIT;
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for (int i=0; i < 10; i++) {
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mj_step(model, data);
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}
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// expect qpos vectors to be numerically different
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#ifndef mjUSESINGLE
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EXPECT_THAT(AsVector(data->qpos, model->nq), Pointwise(Ne(), qposEuler));
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#endif
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// expect qpos vectors to be similar to high precision
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EXPECT_THAT(AsVector(data->qpos, model->nq),
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Pointwise(MjNear(1e-14, 1e-6), qposEuler));
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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// Joint and actuator damping should integrate identically under implicit
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TEST_F(ImplicitIntegratorTest, JointActuatorEquivalent) {
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const std::string xml_path = GetTestDataFilePath(kDampedActuatorsPath);
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mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, nullptr, 0);
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mjData* data = mj_makeData(model);
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// take 1000 steps with Euler
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for (int i=0; i < 1000; i++) {
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mj_step(model, data);
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}
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// expect corresponding joint values to be significantly different
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#ifndef mjUSESINGLE
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EXPECT_GT(fabs(data->qpos[0]-data->qpos[2]), 1e-4);
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EXPECT_GT(fabs(data->qpos[1]-data->qpos[3]), 1e-4);
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#endif
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// reset, take 10 steps with implicit
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mj_resetData(model, data);
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model->opt.integrator = mjINT_IMPLICIT;
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for (int i=0; i < 10; i++) {
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mj_step(model, data);
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}
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// expect corresponding joint values to be insignificantly different
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EXPECT_LT(fabs(data->qpos[0]-data->qpos[2]), MjTol(1e-16, 1e-6));
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EXPECT_LT(fabs(data->qpos[1]-data->qpos[3]), MjTol(1e-16, 1e-6));
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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// Energy conservation: RungeKutta > implicit > Euler
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TEST_F(ImplicitIntegratorTest, EnergyConservation) {
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const std::string xml_path =
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GetTestDataFilePath(kEnergyConservingPendulumPath);
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mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, nullptr, 0);
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mjData* data = mj_makeData(model);
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const int nstep = 500; // number of steps to take
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// take nstep steps with Euler, measure energy (potential + kinetic)
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model->opt.integrator = mjINT_EULER;
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for (int i=0; i < nstep; i++) {
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mj_step(model, data);
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}
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mjtNum energyEuler = data->energy[0] + data->energy[1];
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// take nstep steps with implicit, measure energy
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model->opt.integrator = mjINT_IMPLICIT;
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mj_resetData(model, data);
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for (int i=0; i < nstep; i++) {
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mj_step(model, data);
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}
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mjtNum energyImplicit = data->energy[0] + data->energy[1];
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// take nstep steps with 4th order Runge-Kutta, measure energy
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model->opt.integrator = mjINT_RK4;
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mj_resetData(model, data);
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for (int i=0; i < nstep; i++) {
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mj_step(model, data);
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}
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mjtNum energyRK4 = data->energy[0] + data->energy[1];
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// energy was measured: expect all energies to be nonzero
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EXPECT_NE(energyEuler, 0);
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EXPECT_NE(energyImplicit, 0);
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EXPECT_NE(energyRK4, 0);
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// test conservation: perfectly conserved energy would remain 0.0
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// expect RK4 to be better than implicit
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EXPECT_LT(fabs(energyRK4), fabs(energyImplicit));
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// expect implicit to be better than Euler
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EXPECT_LT(fabs(energyImplicit), fabs(energyEuler));
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mj_deleteData(data);
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mj_deleteModel(model);
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}
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// Energy and angmom conservation for free body with implicitfast (IMR)
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TEST_F(ImplicitIntegratorTest, ConservationMidpoint) {
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// aligned: CoM at joint origin
|
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static constexpr char xml1[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast" timestep="0.01">
|
|
<flag energy="enable" gravity="disable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body>
|
|
<freejoint/>
|
|
<geom type="box" size=".1 .2 .3" mass="1" euler="10 20 30"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
// auto-aligned: CoM at joint origin
|
|
static constexpr char xml2[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast" timestep="0.01">
|
|
<flag energy="enable" gravity="disable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body>
|
|
<freejoint align="true"/>
|
|
<geom type="box" size=".1 .2 .3" mass="1" euler="10 20 30" pos=".03 .02 .01"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
// non-aligned: CoM offset from joint origin
|
|
static constexpr char xml3[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast" timestep="0.01">
|
|
<flag energy="enable" gravity="disable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body>
|
|
<freejoint/>
|
|
<geom type="box" size=".1 .2 .3" mass="1" euler="10 20 30" pos=".03 .02 .01"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
int xml_idx = 1;
|
|
for (auto xml : {xml1, xml2, xml3}) {
|
|
SCOPED_TRACE(testing::Message() << "XML case " << xml_idx++);
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
const int nstep = 500;
|
|
mjtNum energy_drift[2], angmom_drift[2]; // [0]=midpoint, [1]=rk4
|
|
|
|
for (int integrator : {mjINT_IMPLICITFAST, mjINT_RK4}) {
|
|
int idx = (integrator == mjINT_IMPLICITFAST) ? 0 : 1;
|
|
model->opt.integrator = integrator;
|
|
|
|
// reset
|
|
mj_resetData(model, data);
|
|
data->qvel[3] = 1.0;
|
|
data->qvel[4] = 2.0;
|
|
data->qvel[5] = 3.0;
|
|
mj_forward(model, data);
|
|
mjtNum initial_energy = data->energy[1];
|
|
mjtNum initial_angmom[3];
|
|
mj_subtreeVel(model, data);
|
|
mju_copy3(initial_angmom, data->subtree_angmom);
|
|
|
|
for (int i=0; i < nstep; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
energy_drift[idx] = fabs(data->energy[1] - initial_energy);
|
|
mj_subtreeVel(model, data);
|
|
mjtNum angmom_err[3];
|
|
mju_sub3(angmom_err, data->subtree_angmom, initial_angmom);
|
|
angmom_drift[idx] = mju_norm3(angmom_err);
|
|
}
|
|
|
|
// midpoint should conserve energy better than RK4 (double only)
|
|
#ifndef mjUSESINGLE
|
|
EXPECT_LT(energy_drift[0], energy_drift[1]);
|
|
#endif
|
|
|
|
// both should conserve angular momentum well
|
|
EXPECT_LT(angmom_drift[0], MjTol(1e-3, 1e-2));
|
|
EXPECT_LT(angmom_drift[1], MjTol(1e-3, 1e-2));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
}
|
|
|
|
// verify second-order convergence of midpoint integration
|
|
TEST_F(ImplicitIntegratorTest, MidpointConvergenceOrder) {
|
|
// aligned: CoM at joint origin
|
|
static constexpr char xml1[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast">
|
|
<flag gravity="disable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body>
|
|
<freejoint/>
|
|
<geom type="box" size=".1 .2 .3" mass="1" euler="10 20 30"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
// non-aligned: CoM offset from joint origin
|
|
static constexpr char xml2[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast">
|
|
<flag gravity="disable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body>
|
|
<freejoint/>
|
|
<geom type="box" size=".1 .2 .3" mass="1" euler="10 20 30"
|
|
pos=".05 .03 .02"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
int xml_idx = 1;
|
|
for (auto xml : {xml1, xml2}) {
|
|
SCOPED_TRACE(testing::Message() << "XML case " << xml_idx++);
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjtNum T = 1.0;
|
|
mjtNum h_coarse = 0.02;
|
|
mjtNum quat_coarse[4], quat_fine[4], quat_ref[4];
|
|
|
|
auto run = [&](mjtNum h, mjtNum quat_out[4]) {
|
|
model->opt.timestep = h;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
data->qvel[3] = 1.0;
|
|
data->qvel[4] = 2.0;
|
|
data->qvel[5] = 3.0;
|
|
|
|
int nstep = (int)(T / h + 0.5);
|
|
for (int i = 0; i < nstep; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
mju_copy4(quat_out, data->qpos + 3);
|
|
mj_deleteData(data);
|
|
};
|
|
|
|
run(h_coarse, quat_coarse);
|
|
run(h_coarse / 2, quat_fine);
|
|
run(h_coarse / 16, quat_ref);
|
|
|
|
// quaternion distance: ||quat - quat_ref|| (handles sign ambiguity)
|
|
auto quat_dist = [](const mjtNum a[4], const mjtNum b[4]) -> mjtNum {
|
|
mjtNum pos = 0, neg = 0;
|
|
for (int i = 0; i < 4; i++) {
|
|
pos += (a[i] - b[i]) * (a[i] - b[i]);
|
|
neg += (a[i] + b[i]) * (a[i] + b[i]);
|
|
}
|
|
return mju_sqrt(mju_min(pos, neg));
|
|
};
|
|
|
|
mjtNum err_coarse = quat_dist(quat_coarse, quat_ref);
|
|
mjtNum err_fine = quat_dist(quat_fine, quat_ref);
|
|
|
|
// second-order: error ratio should be ~4 when halving timestep
|
|
mjtNum ratio = err_coarse / err_fine;
|
|
EXPECT_GT(ratio, 3.5);
|
|
EXPECT_LT(ratio, 4.5);
|
|
|
|
mj_deleteModel(model);
|
|
}
|
|
}
|
|
|
|
// verify that Newton iteration in mj_midpoint converges quickly (aligned case)
|
|
TEST_F(ImplicitIntegratorTest, MidpointNewtonConvergence) {
|
|
// inertia ratios: symmetric, mildly asymmetric, extremely asymmetric
|
|
mjtNum inertias[][3] = {
|
|
{1.0, 1.0, 1.0},
|
|
{1.0, 2.0, 3.0},
|
|
{0.01, 1.0, 100.0},
|
|
{1.0, 1.0, 1000.0},
|
|
};
|
|
|
|
mjtNum timesteps[] = {0.001, 0.01, 0.1};
|
|
|
|
mjtNum velocities[][3] = {
|
|
{1.0, 2.0, 3.0},
|
|
{100.0, 0.0, 0.0},
|
|
{10.0, 10.0, 10.0},
|
|
{0.01, 0.01, 100.0},
|
|
};
|
|
|
|
mjtNum q_identity[4] = {1, 0, 0, 0};
|
|
mjtNum torques[][3] = {
|
|
{0, 0, 0},
|
|
{10.0, 20.0, 30.0},
|
|
{100.0, 0.0, 0.0},
|
|
{0.0, 0.0, 100.0},
|
|
};
|
|
|
|
int max_iter = 0;
|
|
int total_iter = 0;
|
|
int ncases = 0;
|
|
|
|
for (auto& I : inertias) {
|
|
for (mjtNum h : timesteps) {
|
|
for (auto& w : velocities) {
|
|
for (auto& tau : torques) {
|
|
mjtNum vel[6] = {0, 0, 0, w[0], w[1], w[2]};
|
|
mjtNum tau_ext[6] = {0, 0, 0, tau[0], tau[1], tau[2]};
|
|
mjtNum v_new[6];
|
|
mjtNum ipos[3] = {0, 0, 0};
|
|
int niter = mj_midpoint(1.0, I, ipos, q_identity, q_identity, vel,
|
|
tau_ext, NULL, h, v_new);
|
|
EXPECT_LT(niter, 10)
|
|
<< "Failed for I=(" << I[0] << "," << I[1] << "," << I[2] << ")"
|
|
<< " h=" << h
|
|
<< " w=(" << w[0] << "," << w[1] << "," << w[2] << ")"
|
|
<< " tau=(" << tau[0] << "," << tau[1] << "," << tau[2] << ")";
|
|
max_iter = std::max(max_iter, niter);
|
|
total_iter += niter;
|
|
ncases++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
EXPECT_LE(max_iter, 4);
|
|
EXPECT_LT((mjtNum)total_iter / ncases, 2.0);
|
|
}
|
|
|
|
// verify that Newton iteration in mj_midpoint converges quickly (non-aligned)
|
|
TEST_F(ImplicitIntegratorTest, MidpointFullNewtonConvergence) {
|
|
mjtNum masses[] = {0.1, 1.0, 10.0};
|
|
|
|
mjtNum inertias[][3] = {
|
|
{1.0, 1.0, 1.0},
|
|
{1.0, 2.0, 3.0},
|
|
{0.01, 1.0, 100.0},
|
|
};
|
|
|
|
mjtNum offsets[][3] = {
|
|
{0.1, 0.0, 0.0},
|
|
{0.05, 0.03, 0.02},
|
|
{0.0, 0.0, 0.5},
|
|
};
|
|
|
|
mjtNum timesteps[] = {0.001, 0.01, 0.1};
|
|
|
|
mjtNum velocities[][6] = {
|
|
{1.0, 0.0, 0.0, 1.0, 2.0, 3.0},
|
|
{0.0, 0.0, 0.0, 10.0, 10.0, 10.0},
|
|
{5.0, 5.0, 5.0, 0.01, 0.01, 100.0},
|
|
};
|
|
|
|
mjtNum q_identity[4] = {1, 0, 0, 0};
|
|
mjtNum forces[][6] = {
|
|
{0, 0, 0, 0, 0, 0},
|
|
{10.0, 20.0, 30.0, 1.0, 2.0, 3.0},
|
|
};
|
|
|
|
int max_iter = 0;
|
|
int total_iter = 0;
|
|
int ncases = 0;
|
|
|
|
for (mjtNum mass : masses) {
|
|
for (auto& I : inertias) {
|
|
for (auto& r : offsets) {
|
|
for (mjtNum h : timesteps) {
|
|
for (auto& vel : velocities) {
|
|
for (auto& frc : forces) {
|
|
mjtNum v_new[6];
|
|
int niter = mj_midpoint(mass, I, r, q_identity, q_identity,
|
|
vel, frc, NULL, h, v_new);
|
|
EXPECT_LT(niter, 10)
|
|
<< "Failed for mass=" << mass
|
|
<< " I=(" << I[0] << "," << I[1] << "," << I[2] << ")"
|
|
<< " r=(" << r[0] << "," << r[1] << "," << r[2] << ")"
|
|
<< " h=" << h;
|
|
max_iter = std::max(max_iter, niter);
|
|
total_iter += niter;
|
|
ncases++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
EXPECT_LE(max_iter, 6);
|
|
EXPECT_LT((mjtNum)total_iter / ncases, 3.0);
|
|
}
|
|
|
|
// verify midpoint eligibility: compare with/without invdiscrete
|
|
// if trajectories differ, midpoint was applied
|
|
// if trajectories match, midpoint was skipped
|
|
TEST_F(ImplicitIntegratorTest, MidpointEligibility) {
|
|
// free body with asymmetric inertia, optionally near a plane
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast" timestep="0.01">
|
|
<flag energy="enable"/>
|
|
</option>
|
|
<worldbody>
|
|
<geom type="plane" size="5 5 0.1"/>
|
|
<body name="free" pos="0 0 2">
|
|
<freejoint/>
|
|
<geom type="ellipsoid" size="0.3 0.2 0.1" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
char error[1024];
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m);
|
|
mjData* d2 = mj_makeData(m);
|
|
int nsteps = 50;
|
|
|
|
auto spin_and_compare = [&](const char* label,
|
|
bool expect_midpoint) {
|
|
mj_resetData(m, d1);
|
|
mj_resetData(m, d2);
|
|
d1->qvel[3] = d2->qvel[3] = 5;
|
|
d1->qvel[4] = d2->qvel[4] = 3;
|
|
d1->qvel[5] = d2->qvel[5] = 1;
|
|
|
|
// d1: midpoint enabled (default)
|
|
m->opt.enableflags &= ~mjENBL_INVDISCRETE;
|
|
for (int i = 0; i < nsteps; i++) mj_step(m, d1);
|
|
|
|
// d2: midpoint disabled
|
|
m->opt.enableflags |= mjENBL_INVDISCRETE;
|
|
mj_resetData(m, d2);
|
|
d2->qvel[3] = 5; d2->qvel[4] = 3; d2->qvel[5] = 1;
|
|
for (int i = 0; i < nsteps; i++) mj_step(m, d2);
|
|
m->opt.enableflags &= ~mjENBL_INVDISCRETE;
|
|
|
|
// compare angular velocities
|
|
mjtNum diff = 0;
|
|
for (int k = 3; k < 6; k++) {
|
|
mjtNum d = d1->qvel[k] - d2->qvel[k];
|
|
diff += d * d;
|
|
}
|
|
if (expect_midpoint) {
|
|
EXPECT_GT(diff, 1e-6)
|
|
<< label << ": expected midpoint to be applied";
|
|
} else {
|
|
EXPECT_LT(diff, 1e-20)
|
|
<< label << ": expected midpoint to be skipped";
|
|
}
|
|
};
|
|
|
|
// case 1: free body in vacuum, implicitfast -> midpoint applied
|
|
m->opt.integrator = mjINT_IMPLICITFAST;
|
|
m->opt.density = 0;
|
|
m->opt.viscosity = 0;
|
|
spin_and_compare("vacuum+implicitfast", true);
|
|
|
|
// case 2: implicit integrator -> midpoint NOT applied
|
|
m->opt.integrator = mjINT_IMPLICIT;
|
|
spin_and_compare("vacuum+implicit", false);
|
|
|
|
// case 3: fluid (nonzero density) -> midpoint NOT applied
|
|
m->opt.integrator = mjINT_IMPLICITFAST;
|
|
m->opt.density = 1.2;
|
|
spin_and_compare("fluid+implicitfast", false);
|
|
m->opt.density = 0;
|
|
|
|
// case 4: fluid (nonzero viscosity) -> midpoint NOT applied
|
|
m->opt.viscosity = 0.001;
|
|
spin_and_compare("viscosity+implicitfast", false);
|
|
m->opt.viscosity = 0;
|
|
|
|
// case 5: body with active contacts -> midpoint NOT applied
|
|
// test both island-enabled and island-disabled branches
|
|
for (int disable_island = 0; disable_island < 2; disable_island++) {
|
|
m->opt.integrator = mjINT_IMPLICITFAST;
|
|
if (disable_island) {
|
|
m->opt.disableflags |= mjDSBL_ISLAND;
|
|
} else {
|
|
m->opt.disableflags &= ~mjDSBL_ISLAND;
|
|
}
|
|
|
|
mj_resetData(m, d1);
|
|
mj_resetData(m, d2);
|
|
d1->qpos[2] = d2->qpos[2] = 0.05;
|
|
d1->qvel[3] = d2->qvel[3] = 5;
|
|
d1->qvel[4] = d2->qvel[4] = 3;
|
|
d1->qvel[5] = d2->qvel[5] = 1;
|
|
|
|
// verify contacts are active
|
|
mj_forward(m, d1);
|
|
ASSERT_GT(d1->ncon, 0) << "body should be in contact with the plane";
|
|
|
|
// single step with midpoint enabled
|
|
mj_resetData(m, d1);
|
|
d1->qpos[2] = 0.05;
|
|
d1->qvel[3] = 5; d1->qvel[4] = 3; d1->qvel[5] = 1;
|
|
m->opt.enableflags &= ~mjENBL_INVDISCRETE;
|
|
mj_step(m, d1);
|
|
|
|
// single step with midpoint disabled
|
|
mj_resetData(m, d2);
|
|
d2->qpos[2] = 0.05;
|
|
d2->qvel[3] = 5; d2->qvel[4] = 3; d2->qvel[5] = 1;
|
|
m->opt.enableflags |= mjENBL_INVDISCRETE;
|
|
mj_step(m, d2);
|
|
m->opt.enableflags &= ~mjENBL_INVDISCRETE;
|
|
|
|
mjtNum diff = 0;
|
|
for (int k = 0; k < m->nv; k++) {
|
|
mjtNum d = d1->qvel[k] - d2->qvel[k];
|
|
diff += d * d;
|
|
}
|
|
EXPECT_LT(diff, 1e-20)
|
|
<< "contact (island " << (disable_island ? "disabled" : "enabled")
|
|
<< "): expected midpoint to be skipped";
|
|
}
|
|
m->opt.disableflags &= ~mjDSBL_ISLAND;
|
|
|
|
mj_deleteData(d2);
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
// model with degenerate translational inertia
|
|
TEST_F(ForwardTest, DegenerateInertia) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast" cone="elliptic">
|
|
<flag gravity="disable" diagexact="enable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body name="1" pos="0.05 0.3 0">
|
|
<joint name="1" axis="0 1 0"/>
|
|
<geom type="capsule" size="0.1 0.5"/>
|
|
</body>
|
|
<body name="2">
|
|
<joint name="2" axis="1 0 0" stiffness="1" springref="90"/>
|
|
<geom type="capsule" size="0.1 0.5"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
for (int i = 0; i < 1000; i++) {
|
|
mj_step(model, data);
|
|
EXPECT_EQ(data->warning[mjWARN_BADQACC].number, 0)
|
|
<< "divergence at timestep " << i;
|
|
if (data->warning[mjWARN_BADQACC].number != 0) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ForwardTest, ControlClamping) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<geom size="1"/>
|
|
<joint name="slide" type="slide" axis="1 0 0"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor name="unclamped" joint="slide"/>
|
|
<motor name="clamped" joint="slide" ctrllimited="true" ctrlrange="-1 1"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// for the unclamped actuator, ctrl={1, 2} produce different accelerations
|
|
data->ctrl[0] = 1;
|
|
mj_forward(model, data);
|
|
mjtNum qacc1 = data->qacc[0];
|
|
data->ctrl[0] = 2;
|
|
mj_forward(model, data);
|
|
mjtNum qacc2 = data->qacc[0];
|
|
EXPECT_NE(qacc1, qacc2);
|
|
|
|
// for the clamped actuator, ctrl={1, 2} produce identical accelerations
|
|
data->ctrl[1] = 1;
|
|
mj_forward(model, data);
|
|
qacc1 = data->qacc[0];
|
|
data->ctrl[1] = 2;
|
|
mj_forward(model, data);
|
|
qacc2 = data->qacc[0];
|
|
EXPECT_EQ(qacc1, qacc2);
|
|
|
|
// data->ctrl[1] remains pristine
|
|
EXPECT_EQ(data->ctrl[1], 2);
|
|
|
|
// install warning handler
|
|
static char warning[1024];
|
|
warning[0] = '\0';
|
|
mju_user_warning = [](const char* msg) {
|
|
util::strcpy_arr(warning, msg);
|
|
};
|
|
|
|
// for the unclamped actuator, huge raises warning
|
|
data->ctrl[0] = 10*mjMAXVAL;
|
|
mj_forward(model, data);
|
|
EXPECT_THAT(warning,
|
|
HasSubstr("Nan, Inf or huge value in CTRL at ACTUATOR 0"));
|
|
|
|
// for the clamped actuator, huge does not raise warning
|
|
mj_resetData(model, data);
|
|
warning[0] = '\0';
|
|
data->ctrl[1] = 10*mjMAXVAL;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(warning[0], '\0');
|
|
|
|
// for the clamped actuator, NaN raises warning
|
|
mj_resetData(model, data);
|
|
data->ctrl[1] = std::numeric_limits<double>::quiet_NaN();
|
|
mj_forward(model, data);
|
|
EXPECT_THAT(warning,
|
|
HasSubstr("Nan, Inf or huge value in CTRL at ACTUATOR 1"));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
void control_callback(const mjModel* m, mjData *d) {
|
|
d->ctrl[0] = 2;
|
|
}
|
|
|
|
TEST_F(ForwardTest, MjcbControlDisabled) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<geom size="1"/>
|
|
<joint name="hinge"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="hinge"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// install global control callback
|
|
mjcb_control = control_callback;
|
|
|
|
// call forward
|
|
mj_forward(model, data);
|
|
// expect that callback was used
|
|
EXPECT_EQ(data->ctrl[0], 2.0);
|
|
|
|
// reset, disable actuation, call forward
|
|
mj_resetData(model, data);
|
|
model->opt.disableflags |= mjDSBL_ACTUATION;
|
|
mj_forward(model, data);
|
|
// expect that callback was not used
|
|
EXPECT_EQ(data->ctrl[0], 0.0);
|
|
|
|
// remove global control callback
|
|
mjcb_control = nullptr;
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ForwardTest, gravcomp) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -10" />
|
|
<worldbody>
|
|
<body>
|
|
<joint type="slide" axis="0 0 1"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
<body pos="3 0 0" gravcomp="1">
|
|
<joint type="slide" axis="0 0 1"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
<body pos="6 0 0" gravcomp="2">
|
|
<joint type="slide" axis="0 0 1"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjData* data = mj_makeData(model);
|
|
while (data->time < 1) { mj_step(model, data); }
|
|
|
|
mjtNum dist = 0.5*mju_norm3(model->opt.gravity)*(data->time*data->time);
|
|
|
|
// expect that body 1 moved down, allowing some slack from our estimate
|
|
EXPECT_NEAR(data->qpos[0], -dist, 0.011);
|
|
|
|
// expect that body 2 does not move
|
|
EXPECT_EQ(data->qpos[1], 0.0);
|
|
|
|
// expect that body 3 moves up the same distance that body 0 moved down
|
|
EXPECT_EQ(data->qpos[0], -data->qpos[2]);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// test disabling of equality constraints
|
|
TEST_F(ForwardTest, eq_active) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="vertical" type="slide" axis="0 0 1"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<equality>
|
|
<joint joint1="vertical"/>
|
|
</equality>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// simulate for 1 second
|
|
while (data->time < 1) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
// expect that the body has barely moved
|
|
EXPECT_LT(mju_abs(data->qpos[0]), 0.001);
|
|
|
|
// turn the equality off, simulate for another second
|
|
data->eq_active[0] = 0;
|
|
while (data->time < 2) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
// expect that the body has fallen about 5m
|
|
EXPECT_LT(data->qpos[0], -4.5);
|
|
EXPECT_GT(data->qpos[0], -5.5);
|
|
|
|
// turn the equality back on, simulate for another second
|
|
data->eq_active[0] = 1;
|
|
while (data->time < 3) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
// expect that the body has snapped back
|
|
EXPECT_LT(mju_abs(data->qpos[0]), 0.001);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// test that normalized and denormalized quats give the same result
|
|
TEST_F(ForwardTest, NormalizeQuats) {
|
|
#ifdef mjUSESINGLE
|
|
GTEST_SKIP() << "Skipping in float32: exact mjData comparison infeasible.";
|
|
#endif
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicit">
|
|
<flag warmstart="disable" energy="enable"/>
|
|
</option>
|
|
<worldbody>
|
|
<body name="free">
|
|
<freejoint/>
|
|
<geom size="1" pos=".1 .2 .3"/>
|
|
</body>
|
|
<body pos="3 0 0">
|
|
<joint name="ball" type="ball" stiffness="100" range="0 10"/>
|
|
<geom size="1" pos=".1 .2 .3"/>
|
|
</body>
|
|
</worldbody>
|
|
<sensor>
|
|
<ballquat joint="ball"/>
|
|
<framequat objtype="body" objname="free"/>
|
|
</sensor>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjData* data_u = mj_makeData(model);
|
|
|
|
// we'll compare all the memory, so unpoison it first
|
|
#ifdef MEMORY_SANITIZER
|
|
__msan_unpoison(data_u->buffer, data_u->nbuffer);
|
|
__msan_unpoison(data_u->arena, data_u->narena);
|
|
#endif
|
|
|
|
// set quats to denormalized values, non-zero velocities
|
|
for (int i = 3; i < model->nq; i++) data_u->qpos[i] = i;
|
|
for (int i = 0; i < model->nv; i++) data_u->qvel[i] = 0.1*i;
|
|
|
|
// copy data and normalize quats
|
|
mjData* data_n = mj_copyData(nullptr, model, data_u);
|
|
mj_normalizeQuat(model, data_n->qpos);
|
|
|
|
// call forward, expect quats to be untouched
|
|
mj_forward(model, data_u);
|
|
for (int i = 3; i < model->nq; i++) {
|
|
EXPECT_EQ(data_u->qpos[i], (mjtNum)i);
|
|
}
|
|
|
|
// expect that the ball joint limit is active
|
|
EXPECT_EQ(data_u->nl, 1);
|
|
|
|
// step both models
|
|
mj_step(model, data_u);
|
|
mj_step(model, data_n);
|
|
|
|
// expect everything to match
|
|
#define X(type, name, nr, nc) \
|
|
for (int i = 0; i < model->nr; i++) \
|
|
for (int j = 0; j < nc; j++) \
|
|
ExpectNear(data_n->name[i*nc+j], data_u->name[i*nc+j]);
|
|
MJDATA_POINTERS;
|
|
#undef X
|
|
|
|
// repeat the above with RK4 integrator
|
|
model->opt.integrator = mjINT_RK4;
|
|
|
|
// reset data, unpoison
|
|
mj_resetData(model, data_u);
|
|
#ifdef MEMORY_SANITIZER
|
|
__msan_unpoison(data_u->buffer, data_u->nbuffer);
|
|
__msan_unpoison(data_u->arena, data_u->narena);
|
|
#endif
|
|
|
|
// set quats to un-normalized values, non-zero velocities
|
|
for (int i = 3; i < model->nq; i++) data_u->qpos[i] = i;
|
|
for (int i = 0; i < model->nv; i++) data_u->qvel[i] = 0.1*i;
|
|
|
|
// copy data and normalize quats
|
|
mj_copyData(data_n, model, data_u);
|
|
mj_normalizeQuat(model, data_n->qpos);
|
|
|
|
// step both models
|
|
mj_step(model, data_u);
|
|
mj_step(model, data_n);
|
|
|
|
// expect everything to match
|
|
#define X(type, name, nr, nc) \
|
|
for (int i = 0; i < model->nr; i++) \
|
|
for (int j = 0; j < nc; j++) \
|
|
ExpectNear(data_n->name[i*nc+j], data_u->name[i*nc+j]);
|
|
MJDATA_POINTERS;
|
|
#undef X
|
|
|
|
mj_deleteData(data_n);
|
|
mj_deleteData(data_u);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// test that normalized and denormalized quats give the same result
|
|
TEST_F(ForwardTest, MocapQuats) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body name="mocap" mocap="true" quat="1 1 1 1">
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<sensor>
|
|
<framequat objtype="body" objname="mocap"/>
|
|
</sensor>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjData* data = mj_makeData(model);
|
|
mj_forward(model, data);
|
|
|
|
// expect mocap_quat to be normalized (by the compiler)
|
|
for (int i = 0; i < 4; i++) {
|
|
EXPECT_NEAR(data->mocap_quat[i], 0.5, MjTol(0, 1e-6));
|
|
EXPECT_NEAR(data->xquat[4+i], 0.5, MjTol(0, 1e-6));
|
|
}
|
|
|
|
// write denormalized quats to mocap_quat, call forward again
|
|
for (int i = 0; i < 4; i++) {
|
|
data->mocap_quat[i] = 1;
|
|
}
|
|
mj_forward(model, data);
|
|
|
|
// expect mocap_quat to remain denormalized, but xquat to be normalized
|
|
for (int i = 0; i < 4; i++) {
|
|
EXPECT_NEAR(data->mocap_quat[i], 1, MjTol(0, 1e-6));
|
|
EXPECT_NEAR(data->xquat[4+i], 0.5, MjTol(0, 1e-6));
|
|
}
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// user defined 2nd-order activation dynamics: frequency-controlled oscillator
|
|
// note that scalar mjcb_act_dyn callbacks are expected to return act_dot, but
|
|
// since we have a vector output we write into act_dot directly
|
|
mjtNum oscillator(const mjModel* m, const mjData *d, int id) {
|
|
// check that actnum == 2
|
|
if (m->actuator_actnum[id] != 2) {
|
|
mju_error("callback expected actnum == 2");
|
|
}
|
|
|
|
// get pointers to activations (inputs) and their derivatives (outputs)
|
|
mjtNum* act = d->act + m->actuator_actadr[id];
|
|
mjtNum* act_dot = d->act_dot + m->actuator_actadr[id];
|
|
|
|
// harmonic oscillator with controlled frequency
|
|
mjtNum frequency = 2*mjPI*d->ctrl[id];
|
|
act_dot[0] = -act[1] * frequency;
|
|
act_dot[1] = act[0] * frequency;
|
|
|
|
return 0; // ignored by caller
|
|
}
|
|
|
|
TEST_F(ForwardTest, MjcbActDynSecondOrderExpectsActnum) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="1e-4"/>
|
|
<worldbody>
|
|
<body>
|
|
<geom size="1"/>
|
|
<joint name="hinge"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<general joint="hinge" dyntype="user" actdim="2"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// install global dynamics callback
|
|
mjcb_act_dyn = oscillator;
|
|
|
|
// for two arbitrary frequencies, compare actuator force as output by the
|
|
// user-defined oscillator and analytical sine function
|
|
for (mjtNum frequency : {1.5, 0.7}) {
|
|
mj_resetData(model, data);
|
|
data->ctrl[0] = frequency; // set desired oscillation frequency
|
|
data->act[0] = 1; // initialise activation
|
|
|
|
// simulate and compare to sine function
|
|
while (data->time < 1) {
|
|
mjtNum expected_force = mju_sin(2*mjPI*data->time*frequency);
|
|
mj_step(model, data);
|
|
EXPECT_NEAR(data->actuator_force[0], expected_force, .01);
|
|
}
|
|
}
|
|
|
|
// uninstall global dynamics callback
|
|
mjcb_act_dyn = nullptr;
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// ------------------------------ actuators -----------------------------------
|
|
|
|
using ActuatorTest = MujocoTest;
|
|
|
|
TEST_F(ActuatorTest, ExpectedAdhesionForce) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -1"/>
|
|
|
|
<worldbody>
|
|
<body name="static">
|
|
<!-- small increase to size to ensure contact -->
|
|
<geom size=".02001" pos=" .01 .01 .07"/>
|
|
<geom size=".02001" pos="-.01 .01 .07"/>
|
|
<geom size=".02001" pos=" .01 -.01 .07"/>
|
|
<geom size=".02001" pos="-.01 -.01 .07"/>
|
|
</body>
|
|
<body name="free">
|
|
<freejoint/>
|
|
<geom type="box" size=".05 .05 .05" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<adhesion body="static" ctrlrange="0 2"/>
|
|
<adhesion body="free" ctrlrange="0 2"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// iterate over cone type
|
|
for (mjtCone cone : {mjCONE_ELLIPTIC, mjCONE_PYRAMIDAL}) {
|
|
// set cone
|
|
model->opt.cone = cone;
|
|
// iterate over condim
|
|
for (int condim : {1, 3, 4, 6}) {
|
|
// set condim
|
|
for (int id=0; id < model->ngeom; id++) {
|
|
model->geom_condim[id] = condim;
|
|
}
|
|
// iterate over actuators
|
|
for (int id=0; id < 2; id++) {
|
|
// set ctrl > 1, expect free body to not fall
|
|
mj_resetData(model, data);
|
|
data->ctrl[id] = 1.01;
|
|
for (int i = 0; i < 100; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
// moved down at most 10 microns
|
|
EXPECT_GT(data->qpos[2], -1e-5);
|
|
|
|
// set ctrl < 1, expect free body to fall below 1cm
|
|
mj_resetData(model, data);
|
|
data->ctrl[id] = 0.99;
|
|
for (int i = 0; i < 100; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
// fell lower than 1cm
|
|
EXPECT_LT(data->qpos[2], -0.01);
|
|
}
|
|
}
|
|
}
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// Actuator force clamping at joints
|
|
TEST_F(ActuatorTest, ActuatorForceClamping) {
|
|
const std::string xml_path = GetTestDataFilePath(kJointForceClamp);
|
|
mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, nullptr, 0);
|
|
mjData* data = mj_makeData(model);
|
|
|
|
data->ctrl[0] = 10;
|
|
mj_forward(model, data);
|
|
|
|
// expect clamping as specified in the model
|
|
EXPECT_NEAR(data->actuator_force[0], 1, MjTol(0, 1e-6));
|
|
EXPECT_NEAR(data->qfrc_actuator[0], 0.4, MjTol(0, 1e-6));
|
|
|
|
// simulate for 2 seconds to gain velocity
|
|
while (data->time < 2) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
// activate damper, expect force to be clamped at lower bound
|
|
data->ctrl[1] = 1;
|
|
mj_forward(model, data);
|
|
EXPECT_NEAR(data->qfrc_actuator[0], -0.4, MjTol(0, 1e-6));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// Apply gravity compensation via actuators
|
|
TEST_F(ActuatorTest, ActuatorGravcomp) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body gravcomp="1">
|
|
<joint name="joint" type="slide" axis="0 0 1"
|
|
actuatorfrcrange="-2 2" actuatorgravcomp="true"/>
|
|
<geom type="box" size=".05 .05 .05" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<motor name="actuator" joint="joint"/>
|
|
</actuator>
|
|
|
|
<sensor>
|
|
<actuatorfrc actuator="actuator"/>
|
|
<jointactuatorfrc joint="joint"/>
|
|
</sensor>
|
|
</mujoco>
|
|
)";
|
|
mjModel* model = LoadModelFromString(xml);
|
|
mjData* data = mj_makeData(model);
|
|
|
|
mj_forward(model, data);
|
|
|
|
// expect force clamping as specified in the model
|
|
EXPECT_EQ(data->actuator_force[0], 0);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 2);
|
|
EXPECT_EQ(data->qfrc_passive[0], 0);
|
|
EXPECT_EQ(data->sensordata[0], 0);
|
|
EXPECT_EQ(data->sensordata[1], 2);
|
|
|
|
// reduce gravity so gravcomp is not clamped
|
|
model->opt.gravity[2] = -1;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->actuator_force[0], 0);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 1);
|
|
EXPECT_EQ(data->qfrc_passive[0], 0);
|
|
EXPECT_EQ(data->sensordata[0], 0);
|
|
EXPECT_EQ(data->sensordata[1], 1);
|
|
|
|
// add control, see that it adds up
|
|
data->ctrl[0] = 0.5;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->actuator_force[0], 0.5);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 1.5);
|
|
EXPECT_EQ(data->qfrc_passive[0], 0);
|
|
EXPECT_EQ(data->sensordata[0], 0.5);
|
|
EXPECT_EQ(data->sensordata[1], 1.5);
|
|
|
|
// add larger control, expect clamping
|
|
data->ctrl[0] = 1.5;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->actuator_force[0], 1.5);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 2);
|
|
EXPECT_EQ(data->qfrc_passive[0], 0);
|
|
EXPECT_EQ(data->sensordata[0], 1.5);
|
|
EXPECT_EQ(data->sensordata[1], 2);
|
|
|
|
// disable actgravcomp, expect gravcomp as a passive force
|
|
model->jnt_actgravcomp[0] = 0;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->actuator_force[0], 1.5);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 1.5);
|
|
EXPECT_EQ(data->qfrc_passive[0], 1);
|
|
EXPECT_EQ(data->sensordata[0], 1.5);
|
|
EXPECT_EQ(data->sensordata[1], 1.5);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// Check that dampratio works as expected
|
|
TEST_F(ActuatorTest, DampRatio) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast"/>
|
|
|
|
<worldbody>
|
|
<body>
|
|
<joint name="slide1" axis="1 0 0" type="slide"/>
|
|
<geom size=".05"/>
|
|
</body>
|
|
|
|
<body pos="0 0 -.15">
|
|
<joint name="slide2" axis="1 0 0" type="slide"/>
|
|
<geom size=".05"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<position name="slightly underdamped" joint="slide1" kp="10" dampratio="0.99"/>
|
|
<position name="slightly overdamped" joint="slide2" kp="10" dampratio="1.01"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
mjModel* model = LoadModelFromString(xml);
|
|
mjData* data = mj_makeData(model);
|
|
|
|
data->qpos[0] = data->qpos[1] = -0.1;
|
|
|
|
mjtNum under_damped = data->qpos[0];
|
|
mjtNum over_damped = data->qpos[1];
|
|
while (data->time < 10) {
|
|
mj_step(model, data);
|
|
under_damped = mju_max(under_damped, data->qpos[0]);
|
|
over_damped = mju_max(over_damped, data->qpos[1]);
|
|
}
|
|
|
|
// expect slightly underdamped to slightly overshoot
|
|
EXPECT_GT(under_damped, 0);
|
|
EXPECT_LT(under_damped, 1e-6);
|
|
|
|
// expect slightly overdamped to slightly undershoot
|
|
EXPECT_LT(over_damped, 0);
|
|
EXPECT_GT(over_damped, -1e-6);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
|
|
// Check dampratio for actuators with nontrivial transmission
|
|
TEST_F(ActuatorTest, DampRatioTendon) {
|
|
const std::string xml_path =
|
|
GetTestDataFilePath("engine/testdata/actuation/tendon_dampratio.xml");
|
|
char error[1000];
|
|
mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
data->ctrl[0] = 1;
|
|
data->ctrl[1] = 4;
|
|
|
|
while (data->time < 1) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
// expect first and second fingers to move together
|
|
double tol = 1e-10;
|
|
EXPECT_THAT(AsVector(data->qpos, 4),
|
|
Pointwise(MjNear(tol, tol), AsVector(data->qpos + 4, 4)));
|
|
EXPECT_THAT(AsVector(data->qvel, 4),
|
|
Pointwise(MjNear(tol, tol), AsVector(data->qvel + 4, 4)));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// ----------------------- DC motor actuators ----------------------------------
|
|
|
|
using DCMotorTest = MujocoTest;
|
|
|
|
TEST_F(DCMotorTest, IntVelocityEquivalence) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicit"/>
|
|
<worldbody>
|
|
<body pos="0 0 0">
|
|
<joint name="slide1" type="slide" axis="1 0 0"/>
|
|
<geom size=".1"/>
|
|
</body>
|
|
<body pos="0 1 0">
|
|
<joint name="slide2" type="slide" axis="1 0 0"/>
|
|
<geom size=".1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<!--
|
|
Equivalence mapping:
|
|
intvelocity force: F = kp * \int(ctrl - v) - kv * v
|
|
dcmotor force: F = (V*K - K^2*v) / R
|
|
where V = ki * \int(ctrl - v) (since kp=0, kd=0)
|
|
|
|
Setting K=1, R=0.2, ki=2 yields:
|
|
F = (2 * \int(ctrl - v) - v) / 0.2
|
|
= 10 * \int(ctrl - v) - 5 * v
|
|
|
|
This perfectly matches intvelocity with kp=10, kv=5.
|
|
-->
|
|
<intvelocity name="intvel" joint="slide1" kp="10" kv="5" actrange="-0.01 0.01"/>
|
|
<dcmotor name="dcmotor" joint="slide2" motorconst="1" resistance="0.2" input="velocity" controller="0 2 0 0 0.01"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Apply a time-varying velocity command
|
|
while (data->time < 1.0) {
|
|
data->ctrl[0] = mju_sin(20 * data->time);
|
|
data->ctrl[1] = mju_sin(20 * data->time);
|
|
mj_step(model, data);
|
|
|
|
// Both actuators should integrate identical states
|
|
EXPECT_MJTNUM_EQ(data->act[0], data->act[1]);
|
|
|
|
// Both bodies should move identically
|
|
EXPECT_NEAR(data->qpos[0], data->qpos[1], MjTol(1e-14, 1e-7));
|
|
EXPECT_NEAR(data->qvel[0], data->qvel[1], MjTol(1e-14, 1e-7));
|
|
EXPECT_NEAR(data->qacc[0], data->qacc[1], MjTol(1e-14, 1e-6));
|
|
|
|
// Both actuators should produce identical force
|
|
EXPECT_NEAR(data->actuator_force[0], data->actuator_force[1],
|
|
MjTol(1e-14, 1e-6));
|
|
}
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, StatelessSteadyState) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
double K = 0.05;
|
|
double R = 2.0;
|
|
double V = 12.0;
|
|
double omega = 3.0;
|
|
|
|
data->ctrl[0] = V;
|
|
data->qvel[0] = omega;
|
|
mj_forward(model, data);
|
|
|
|
double expected_force = K / R * (V - K * omega);
|
|
EXPECT_NEAR(data->actuator_force[0], expected_force, MjTol(1e-12, 1e-5));
|
|
EXPECT_EQ(model->actuator_actnum[0], 0);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, CurrentFilterConverges) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.0001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint" damping="1000"/>
|
|
<geom size="1" mass="100"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
inductance="0.01 0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
ASSERT_EQ(model->actuator_actnum[0], 1);
|
|
|
|
double K = 0.05;
|
|
double R = 2.0;
|
|
double V = 12.0;
|
|
|
|
data->ctrl[0] = V;
|
|
for (int i = 0; i < 10000; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
double omega = data->qvel[0];
|
|
double i_ss = V / R - K / R * omega;
|
|
double expected_force = K * i_ss;
|
|
|
|
EXPECT_NEAR(data->act[0], i_ss, MjTol(1e-6, 1e-4));
|
|
EXPECT_NEAR(data->actuator_force[0], expected_force, MjTol(1e-6, 1e-4));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, CurrentFilterExactIntegration) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint" damping="10000"/>
|
|
<geom size="1" mass="10000"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
inductance="0.01 0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
double R = 2.0;
|
|
double te = 0.01 / R;
|
|
double V = 12.0;
|
|
|
|
data->ctrl[0] = V;
|
|
mj_step(model, data);
|
|
|
|
double h = model->opt.timestep;
|
|
double exact_current = V / R * (1 - mju_exp(-h / te));
|
|
EXPECT_NEAR(data->act[0], exact_current, MjTol(1e-10, 1e-4));
|
|
|
|
double euler_current = V / R * h / te;
|
|
EXPECT_GT(std::abs(data->act[0] - euler_current),
|
|
std::abs(data->act[0] - exact_current));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, CoggingTorque) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
cogging="0.1 6 0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
double A = 0.1, Np = 6, phi = 0;
|
|
double K = 0.05, R = 2.0;
|
|
double V = 5.0;
|
|
double pos = 1.0;
|
|
|
|
data->ctrl[0] = V;
|
|
data->qpos[0] = pos;
|
|
mj_forward(model, data);
|
|
|
|
double electrical_force = K / R * V;
|
|
double cogging = A * mju_sin(Np * pos + phi);
|
|
EXPECT_NEAR(data->actuator_force[0], electrical_force + cogging,
|
|
MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, CoggingBypassesSaturation) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
saturation="0.001 0" cogging="0.1 6 0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
double A = 0.1, Np = 6, phi = 0;
|
|
double pos = 1.0;
|
|
|
|
data->ctrl[0] = 100.0;
|
|
data->qpos[0] = pos;
|
|
mj_forward(model, data);
|
|
|
|
double cogging = A * mju_sin(Np * pos + phi);
|
|
EXPECT_NEAR(model->actuator_forcerange[1], 0.001, MjTol(1e-12, 1e-5));
|
|
EXPECT_GT(mju_abs(data->actuator_force[0]), 0.001);
|
|
EXPECT_NEAR(data->actuator_force[0], 0.001 + cogging, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, LuGreViscousFriction) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
damping="0.01" lugre="100 1 0.5 0.7 10"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
ASSERT_EQ(model->actuator_actnum[0], 1);
|
|
|
|
double sigma1 = 1, sigma2 = 0.01;
|
|
double K = 0.05, R = 2.0;
|
|
double omega = 2.0;
|
|
|
|
data->ctrl[0] = 0;
|
|
data->qvel[0] = omega;
|
|
mj_forward(model, data);
|
|
|
|
EXPECT_MJTNUM_EQ(model->actuator_damping[0], sigma2);
|
|
double electrical_force = K / R * (0 - K * omega);
|
|
double z = data->act[model->actuator_actadr[0]];
|
|
double z_dot = data->act_dot[model->actuator_actadr[0]];
|
|
double lugre_force = 100 * z + sigma1 * z_dot;
|
|
EXPECT_NEAR(data->actuator_force[0], electrical_force - lugre_force,
|
|
MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, ThermalRiseAndFall) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint" damping="10000"/>
|
|
<geom size="1" mass="10000"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
thermal="10 5 0 0 25 25"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
int adr = model->actuator_actadr[0];
|
|
ASSERT_EQ(model->actuator_actnum[0], 1);
|
|
EXPECT_EQ(data->act[adr], 0);
|
|
|
|
double R = 2.0, V = 10.0;
|
|
double RT = 10.0, C = 5.0;
|
|
double h = model->opt.timestep;
|
|
double P = V * V / R;
|
|
|
|
data->ctrl[0] = V;
|
|
|
|
mj_step(model, data);
|
|
double dT1 = h * P / C;
|
|
EXPECT_NEAR(data->act[adr], dT1, MjTol(1e-11, 1e-4));
|
|
|
|
mj_step(model, data);
|
|
double dT2 = dT1 + h * (P - dT1 / RT) / C;
|
|
EXPECT_NEAR(data->act[adr], dT2, MjTol(1e-11, 1e-4));
|
|
|
|
data->ctrl[0] = 0;
|
|
mj_step(model, data);
|
|
double dT3 = dT2 + h * (0 - dT2 / RT) / C;
|
|
EXPECT_NEAR(data->act[adr], dT3, MjTol(1e-11, 1e-4));
|
|
EXPECT_LT(data->act[adr], dT2);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, ThermalSteadyState) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint" damping="10000"/>
|
|
<geom size="1" mass="10000"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
thermal="0.1 0.1 0 0 25 25"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
double R = 2.0, V = 10.0;
|
|
double RT = 0.1;
|
|
double dT_ss = RT * V * V / R;
|
|
|
|
data->ctrl[0] = V;
|
|
for (int i = 0; i < 10000; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
int adr = model->actuator_actadr[0];
|
|
EXPECT_NEAR(data->act[adr], dT_ss, 1e-4);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, ThermalAffectsForce) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
thermal="0.1 0.1 0 0.004 25 25"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
double K = 0.05, R = 2.0, V = 10.0;
|
|
double alpha = 0.004;
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
data->ctrl[0] = V;
|
|
data->act[adr] = 0;
|
|
mj_forward(model, data);
|
|
double force_cold = data->actuator_force[0];
|
|
EXPECT_NEAR(force_cold, K / R * V, MjTol(1e-12, 1e-5));
|
|
|
|
double dT = 50;
|
|
data->act[adr] = dT;
|
|
mj_forward(model, data);
|
|
double R_hot = R * (1 + alpha * dT);
|
|
double force_hot = data->actuator_force[0];
|
|
EXPECT_NEAR(force_hot, K / R_hot * V, MjTol(1e-12, 1e-5));
|
|
EXPECT_LT(force_hot, force_cold);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// Temperature slot must be correctly offset past slew and integral states.
|
|
TEST_F(DCMotorTest, ThermalAffectsForceWithController) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
input="position" controller="1.0 1.0 0 5.0 0"
|
|
thermal="0.1 0.1 0 0.004 25 25"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// slot order: slew(0), integral(1), temperature(2)
|
|
ASSERT_EQ(model->actuator_actnum[0], 3);
|
|
int adr = model->actuator_actadr[0];
|
|
int temp_adr = adr + 2; // temperature is slot 2
|
|
|
|
double K = 0.05, R = 2.0, alpha = 0.004;
|
|
double dT = 50;
|
|
data->act[adr] = 1.0; // slew state = ctrl: no rate-limiting applied
|
|
data->act[adr + 1] = 0.0; // integral state x_I = 0
|
|
data->act[temp_adr] = dT; // temperature rise above ambient
|
|
data->ctrl[0] = 1.0; // position setpoint = 1.0, qpos = 0, error = 1.0
|
|
mj_forward(model, data);
|
|
|
|
// u_eff = ctrl = 1.0 (no slew applied since act[slew] == ctrl)
|
|
// V = kp*(u_eff - length) + ki*x_I - kd*omega = 1.0*1.0 + 1.0*0.0 - 0*0 = 1.0
|
|
// R(T) = 2.0 * (1 + 0.004 * 50) = 2.4
|
|
// stateless (no te): force = K/R(T) * V = 0.05/2.4 * 1.0
|
|
double R_hot = R * (1 + alpha * dT);
|
|
EXPECT_NEAR(data->actuator_force[0], K / R_hot * 1.0, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, StatelessPositionMode) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" input="position" controller="2.0 0 0.5 0 0"
|
|
motorconst="0.05" resistance="2.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Position target 5.0, current pos 0.0, current vel 0.0
|
|
data->ctrl[0] = 5.0;
|
|
mj_forward(model, data);
|
|
|
|
// V = Kp * (u - theta) = 2.0 * 5.0 = 10.0
|
|
// force = K / R * V + bias = (0.05 / 2.0) * 10.0 + 0 = 0.25
|
|
EXPECT_NEAR(data->actuator_force[0], 0.25, MjTol(1e-12, 1e-5));
|
|
|
|
// Velocity penalty
|
|
data->qvel[0] = 2.0;
|
|
mj_forward(model, data);
|
|
// V = 10.0 - Kd * omega = 10.0 - (0.5 * 2.0) = 9.0
|
|
// bias = - K^2 / R * omega = -0.0025 / 2.0 * 2.0 = -0.0025
|
|
// force = K / R * V + bias = 0.225 - 0.0025 = 0.2225
|
|
EXPECT_NEAR(data->actuator_force[0], 0.2225, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, StatelessVelocityMode) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" input="velocity" controller="3.0 0 0 0 0"
|
|
motorconst="0.05" resistance="2.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Velocity target 4.0, current vel 1.0
|
|
data->ctrl[0] = 4.0;
|
|
data->qvel[0] = 1.0;
|
|
mj_forward(model, data);
|
|
|
|
// V = Kp * (u - omega) = 3.0 * (4.0 - 1.0) = 9.0
|
|
// bias = - K^2 / R * omega = -0.0025 / 2.0 * 1.0 = -0.00125
|
|
// force = K / R * V + bias = (0.05 / 2.0) * 9.0 - 0.00125 = 0.22375
|
|
EXPECT_NEAR(data->actuator_force[0], 0.22375, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, StatefulPositionMode) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" input="position" controller="2.0 0.5 0.1 10.0 5.0"
|
|
motorconst="0.05" resistance="2.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Controller states: 1 for slew, 1 for ki -> actnum = 2
|
|
ASSERT_EQ(model->actuator_actnum[0], 2);
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
// Current states
|
|
double u_prev = 1.0;
|
|
double x_I = 2.0;
|
|
data->act[adr] = u_prev;
|
|
data->act[adr+1] = x_I;
|
|
|
|
// target 5.0 position, current 0.0
|
|
data->ctrl[0] = 5.0;
|
|
data->qvel[0] = 0.5;
|
|
mj_forward(model, data);
|
|
|
|
// slew bounding: s = 10.0, dt = 0.001. max_change = 0.01
|
|
// Target = 5.0. It is upper bounded by u_prev + 0.01 = 1.01
|
|
EXPECT_NEAR(data->act_dot[adr], 10.0, MjTol(1e-12, 1e-5));
|
|
|
|
// PI error: error = u_eff - length = 1.01 - 0.0 = 1.01
|
|
EXPECT_NEAR(data->act_dot[adr+1], 1.01, MjTol(1e-12, 1e-5));
|
|
|
|
// V = Kp(u_eff - length) + Ki * x_I - Kd * omega
|
|
// V = 2.0 * 1.01 + 0.5 * 2.0 - 0.1 * 0.5 = 2.97
|
|
// bias = - K^2/R * omega = -(0.05)^2 / 2.0 * 0.5 = -0.000625
|
|
// force = K/R * V + bias = 0.025 * 2.97 - 0.000625 = 0.073625
|
|
EXPECT_NEAR(data->actuator_force[0], 0.073625, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, StatefulPositionWithCurrentMode) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" input="position" controller="2.0 0.5 0.1 10.0 5.0"
|
|
motorconst="0.05" resistance="2.0" inductance="1.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Controller states: slew (0), ki (1), current (2). actnum = 3
|
|
ASSERT_EQ(model->actuator_actnum[0], 3);
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
double u_prev = 1.0;
|
|
double x_I = 2.0;
|
|
double current = 0.5;
|
|
data->act[adr] = u_prev;
|
|
data->act[adr+1] = x_I;
|
|
data->act[adr+2] = current;
|
|
|
|
// Target 5.0 position, velocity 0.5
|
|
data->ctrl[0] = 5.0;
|
|
data->qvel[0] = 0.5;
|
|
mj_forward(model, data);
|
|
|
|
// Slew bounding: max_change = 0.01, u_eff = 1.01
|
|
EXPECT_NEAR(data->act_dot[adr], 10.0, MjTol(1e-12, 1e-5));
|
|
|
|
// PI error: error = u_eff - length = 1.01
|
|
EXPECT_NEAR(data->act_dot[adr+1], 1.01, MjTol(1e-12, 1e-5));
|
|
|
|
// Voltage computation:
|
|
// V = Kp(u_eff - length) + Ki * x_I - Kd * omega
|
|
// V = 2.0 * 1.01 + 0.5 * 2.0 - 0.1 * 0.5 = 2.97
|
|
|
|
// Current filter:
|
|
// t_e = L / R = 1.0 / 2.0 = 0.5
|
|
// di/dt = (V/R - K/R * omega - i) / t_e
|
|
// di/dt = (2.97/2.0 - 0.05/2.0 * 0.5 - 0.5) / 0.5
|
|
// di/dt = (1.485 - 0.0125 - 0.5) / 0.5 = 0.9725 / 0.5 = 1.945
|
|
EXPECT_NEAR(data->act_dot[adr+2], 1.945, MjTol(1e-12, 1e-5));
|
|
|
|
// Force is K * next_activation (actearly is always on for DC motors)
|
|
// Inline mj_nextActivation for te = 0.5
|
|
mjtNum te = 0.5;
|
|
mjtNum h = model->opt.timestep;
|
|
mjtNum next_i = 0.5 + data->act_dot[adr+2] * te * (1 - mju_exp(-h / te));
|
|
EXPECT_NEAR(data->actuator_force[0], 0.05 * next_i, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, StatefulVelocityMode) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" input="velocity" controller="3.0 1.0 0 0 2.0"
|
|
motorconst="0.05" resistance="2.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Controller states: 1 for ki (no slew)
|
|
ASSERT_EQ(model->actuator_actnum[0], 1);
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
double x_I = 2.0; // Exactly at Imax limit (Imax = 2.0)
|
|
data->act[adr] = x_I;
|
|
|
|
// target vel 4.0, current vel 1.0
|
|
data->ctrl[0] = 4.0;
|
|
data->qvel[0] = 1.0;
|
|
mj_forward(model, data);
|
|
|
|
// integrate command directly: error = target = 4.0
|
|
// since x_I == Imax (2.0) and error (4.0) > 0, act_dot should be clamped to 0
|
|
EXPECT_NEAR(data->act_dot[adr], 0.0, MjTol(1e-12, 1e-5));
|
|
|
|
// V = Kp * (u_eff - omega) + Ki * (x_I - length)
|
|
// V = 3.0 * (4.0 - 1.0) + 1.0 * (2.0 - 0.0) = 9.0 + 2.0 = 11.0
|
|
// bias = - K^2/R * omega = -(0.05)^2 / 2.0 * 1.0 = -0.00125
|
|
// force = K/R * V + bias = 0.025 * 11.0 - 0.00125 = 0.275 - 0.00125 = 0.27375
|
|
EXPECT_NEAR(data->actuator_force[0], 0.27375, MjTol(1e-12, 1e-5));
|
|
|
|
// repeat with non-zero joint position
|
|
data->qpos[0] = 1.5;
|
|
mj_forward(model, data);
|
|
|
|
// V = 3.0 * (4.0 - 1.0) + 1.0 * (2.0 - 1.5) = 9.0 + 0.5 = 9.5
|
|
// force = K/R * V + bias = 0.025 * 9.5 - 0.00125 = 0.2375 - 0.00125 = 0.23625
|
|
EXPECT_NEAR(data->actuator_force[0], 0.23625, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, CurrentPlusThermal) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint" damping="10000"/>
|
|
<geom size="1" mass="10000"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
inductance="0.01 0" thermal="10 5 0 0.004 25 25"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
ASSERT_EQ(model->actuator_actnum[0], 2);
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
double K = 0.05, R = 2.0, V = 12.0;
|
|
double te = 0.01 / R;
|
|
double RT = 10.0, C = 5.0;
|
|
|
|
double current = 3.0;
|
|
double dT = 10.0;
|
|
data->act[adr] = dT;
|
|
data->act[adr+1] = current;
|
|
data->ctrl[0] = V;
|
|
mj_forward(model, data);
|
|
|
|
// Force uses next_activation (actearly is always on for DC motors)
|
|
// Inline mj_nextActivation for te = 0.01 / R = 0.005
|
|
mjtNum h = model->opt.timestep;
|
|
mjtNum next_i = current + data->act_dot[adr+1] * te * (1 - mju_exp(-h / te));
|
|
EXPECT_NEAR(data->actuator_force[0], K * next_i, MjTol(1e-12, 1e-5));
|
|
|
|
double R_hot = R * (1 + 0.004 * dT);
|
|
double T_dot = (R_hot * current * current - dT / RT) / C;
|
|
EXPECT_NEAR(data->act_dot[adr], T_dot, MjTol(1e-10, 1e-4));
|
|
|
|
double omega = data->qvel[0];
|
|
double i_dot = (V/R_hot - K/R_hot*omega - current) / te;
|
|
EXPECT_NEAR(data->act_dot[adr+1], i_dot, MjTol(1e-10, 1e-3));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, CurrentRateLimit) {
|
|
// Verifies that saturation:current_rate clamps di/dt.
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint" damping="10000"/>
|
|
<geom size="1" mass="10000"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
inductance="0.01 0" saturation="0 0 100"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
ASSERT_EQ(model->actuator_actnum[0], 1);
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
double V = 12.0;
|
|
double dimax = 100.0; // A/s rate limit
|
|
|
|
// unclamped: i_dot = (V/R - 0 - 0) / te = 6 / 0.005 = 1200 A/s >> dimax
|
|
data->act[adr] = 0; // current = 0
|
|
data->ctrl[0] = V;
|
|
mj_forward(model, data);
|
|
|
|
// i_dot should be clipped to +dimax
|
|
EXPECT_NEAR(data->act_dot[adr], dimax, MjTol(1e-12, 1e-5));
|
|
|
|
// reverse: large negative drive
|
|
data->ctrl[0] = -V;
|
|
mj_forward(model, data);
|
|
|
|
// i_dot should be clipped to -dimax
|
|
EXPECT_NEAR(data->act_dot[adr], -dimax, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
|
|
TEST_F(DCMotorTest, VoltageLimit) {
|
|
// verifies that saturation:voltage clamps voltage
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
input="position" controller="1 0 0 0 0 10.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Vmax = 10.0, ctrl = 20.0
|
|
// force = K/R * Vmax = 0.05 / 2.0 * 10.0 = 0.25
|
|
data->ctrl[0] = 20.0;
|
|
mj_forward(model, data);
|
|
|
|
EXPECT_NEAR(data->actuator_force[0], 0.25, MjTol(1e-12, 1e-5));
|
|
|
|
// negative drive
|
|
data->ctrl[0] = -20.0;
|
|
mj_forward(model, data);
|
|
|
|
EXPECT_NEAR(data->actuator_force[0], -0.25, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
|
|
TEST_F(DCMotorTest, IntegralClamp) {
|
|
// verifies that controller Imax clamps integral state
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" input="position" controller="2.0 0.5 0 0 5.0"
|
|
motorconst="0.05" resistance="2.0"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Imax = 5.0
|
|
ASSERT_EQ(model->actuator_actnum[0], 1); // only ki is stateful
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
// set integral state to Imax
|
|
data->act[adr] = 5.0;
|
|
|
|
// set target to generate positive error (ctrl - length)
|
|
data->ctrl[0] = 1.0; // target
|
|
data->qpos[0] = 0.0; // length = 0
|
|
|
|
mj_forward(model, data);
|
|
|
|
// act_dot should be clamped to 0 because act >= Imax and error > 0
|
|
EXPECT_NEAR(data->act_dot[adr], 0.0, MjTol(1e-12, 1e-5));
|
|
|
|
// set target to generate negative error
|
|
data->ctrl[0] = -1.0;
|
|
mj_forward(model, data);
|
|
|
|
// act_dot should be negative (not clamped)
|
|
EXPECT_NEAR(data->act_dot[adr], -1.0, MjTol(1e-12, 1e-5));
|
|
|
|
// set integral state to -Imax
|
|
data->act[adr] = -5.0;
|
|
|
|
// set target to generate negative error
|
|
data->ctrl[0] = -1.0;
|
|
data->qpos[0] = 0.0;
|
|
mj_forward(model, data);
|
|
|
|
// act_dot should be clamped to 0 because act <= -Imax and error < 0
|
|
EXPECT_NEAR(data->act_dot[adr], 0.0, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, LuGreExactIntegration) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1" mass="1e6"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
damping="0.01" lugre="100 1 0.5 0.7 10"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
ASSERT_EQ(model->actuator_actnum[0], 1);
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
double sigma0 = 100, F_C = 0.5, F_S = 0.7, v_S = 10;
|
|
double z0 = 0.002;
|
|
double v = 0.5;
|
|
double h = model->opt.timestep;
|
|
|
|
data->act[adr] = z0;
|
|
data->qvel[0] = v;
|
|
|
|
double ratio = v / v_S;
|
|
double g_v = F_C + (F_S - F_C) * mju_exp(-ratio*ratio);
|
|
double a = -sigma0 * std::abs(v) / g_v;
|
|
double exp_ah = mju_exp(a * h);
|
|
double int_h = (exp_ah - 1) / a;
|
|
double z_new = exp_ah * z0 + int_h * v;
|
|
|
|
mj_step(model, data);
|
|
EXPECT_NEAR(data->act[adr], z_new, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, LuGreSteadyState) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.001"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1" mass="1e6"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
damping="0.01" lugre="100 1 0.5 0.7 10"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
int adr = model->actuator_actadr[0];
|
|
|
|
double sigma0 = 100, sigma2 = 0.01;
|
|
double F_C = 0.5, F_S = 0.7, v_S = 10;
|
|
double K = 0.05, R = 2.0;
|
|
double v = 0.5;
|
|
|
|
data->qvel[0] = v;
|
|
data->ctrl[0] = 0;
|
|
for (int i = 0; i < 10000; i++) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
double ratio = v / v_S;
|
|
double g_v = F_C + (F_S - F_C) * mju_exp(-ratio*ratio);
|
|
double z_ss = g_v / sigma0;
|
|
EXPECT_NEAR(data->act[adr], z_ss, 1e-4);
|
|
|
|
EXPECT_MJTNUM_EQ(model->actuator_damping[0], sigma2);
|
|
double back_emf = K * K / R * data->qvel[0];
|
|
double lugre_ss = g_v;
|
|
EXPECT_NEAR(data->actuator_force[0], -back_emf - lugre_ss, 1e-3);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(DCMotorTest, LuGreBristleSpring) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="joint"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<dcmotor joint="joint" motorconst="0.05" resistance="2.0"
|
|
damping="0.01" lugre="100 1 0.5 0.7 10"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
int adr = model->actuator_actadr[0];
|
|
double sigma0 = 100;
|
|
double X = 0.01;
|
|
|
|
data->act[adr] = X;
|
|
data->ctrl[0] = 0;
|
|
mj_forward(model, data);
|
|
|
|
EXPECT_NEAR(data->actuator_force[0], -sigma0 * X, MjTol(1e-12, 1e-5));
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// ----------------------- filterexact actuators -------------------------------
|
|
|
|
using FilterExactTest = MujocoTest;
|
|
|
|
TEST_F(FilterExactTest, ApproximatesContinuousTime) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<compiler autolimits="true"/>
|
|
<worldbody>
|
|
<body name="box">
|
|
<joint name="slide" type="slide" axis="1 0 0" />
|
|
<geom type="box" size=".05 .05 .05" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<general joint="slide" dyntype="filter" gainprm="1.1" />
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
const mjtNum kSimulationTime = 1.0;
|
|
|
|
// compute act with a small timestep to approximate continuous integration
|
|
model->opt.timestep = 0.001;
|
|
mj_resetData(model, data);
|
|
data->ctrl[0] = 1.0;
|
|
data->act[0] = 0.0;
|
|
for (int i = 0; i < std::round(kSimulationTime / model->opt.timestep); i++) {
|
|
mj_step(model, data);
|
|
}
|
|
mjtNum continuous_act = data->act[0];
|
|
|
|
// compute again with a larger timestep, introducing integration error
|
|
model->opt.timestep = 0.01;
|
|
mj_resetData(model, data);
|
|
data->ctrl[0] = 1.0;
|
|
data->act[0] = 0.0;
|
|
for (int i = 0; i < std::round(kSimulationTime / model->opt.timestep); i++) {
|
|
mj_step(model, data);
|
|
}
|
|
mjtNum discrete_act = data->act[0];
|
|
|
|
// compute a third time with exact integration
|
|
model->actuator_dyntype[0] = mjDYN_FILTEREXACT;
|
|
mj_resetData(model, data);
|
|
data->ctrl[0] = 1.0;
|
|
data->act[0] = 0.0;
|
|
for (int i = 0; i < std::round(kSimulationTime / model->opt.timestep); i++) {
|
|
mj_step(model, data);
|
|
}
|
|
mjtNum exactfilter_act = data->act[0];
|
|
|
|
// expect exact integration to be closer to the small-timestep result
|
|
EXPECT_THAT(std::abs(continuous_act - discrete_act),
|
|
Gt(5*std::abs(continuous_act - exactfilter_act)))
|
|
<< "Using filterexact should make the error at least 5 times smaller";
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(FilterExactTest, TimestepIndependent) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<compiler autolimits="true"/>
|
|
<worldbody>
|
|
<body name="box">
|
|
<joint name="slide" type="slide" axis="1 0 0" />
|
|
<geom type="box" size=".05 .05 .05" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<general joint="slide" dyntype="filterexact" dynprm="0.9" gainprm="1.1"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
const mjtNum kSimulationTime = 1.0;
|
|
|
|
// first, compute act based on a small timestep and exact integration
|
|
model->opt.timestep = 0.01;
|
|
mj_resetData(model, data);
|
|
data->ctrl[0] = 1.0;
|
|
data->act[0] = 0.0;
|
|
for (int i = 0; i < std::round(kSimulationTime / model->opt.timestep); i++) {
|
|
mj_step(model, data);
|
|
}
|
|
mjtNum small_timestep_act = data->act[0];
|
|
|
|
// now change the timestep to a much larger timestep
|
|
model->opt.timestep = 0.1;
|
|
mj_resetData(model, data);
|
|
data->ctrl[0] = 1.0;
|
|
data->act[0] = 0.0;
|
|
for (int i = 0; i < std::round(kSimulationTime / model->opt.timestep); i++) {
|
|
mj_step(model, data);
|
|
}
|
|
mjtNum large_timestep_act = data->act[0];
|
|
|
|
EXPECT_NEAR(small_timestep_act, large_timestep_act, MjTol(1e-14, 1e-6))
|
|
<< "exact integration should be independent of timestep to machine "
|
|
"precision.";
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(FilterExactTest, ActEqualsCtrlWhenTauIsZero) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<compiler autolimits="true"/>
|
|
<worldbody>
|
|
<body name="box">
|
|
<joint name="slide" type="slide" axis="1 0 0" />
|
|
<geom type="box" size=".05 .05 .05" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<general joint="slide" dyntype="filterexact" dynprm="0" gainprm="1.1"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
data->ctrl[0] = 0.5;
|
|
data->act[0] = 0.0;
|
|
mj_step(model, data);
|
|
EXPECT_EQ(data->act[0], data->ctrl[0]);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// ----------------------- actearly actuator attribute -------------------------
|
|
|
|
using ActEarlyTest = MujocoTest;
|
|
|
|
TEST_F(ActEarlyTest, RemovesOneStepDelay) {
|
|
const std::string xml_path =
|
|
GetTestDataFilePath("engine/testdata/actuation/actearly.xml");
|
|
char error[1000];
|
|
mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
ASSERT_EQ(model->nu % 2, 0) << "number of actuators should be even";
|
|
ASSERT_EQ(model->nu, model->na) << "all actuators should be stateful";
|
|
ASSERT_EQ(model->nq, model->nu);
|
|
EXPECT_GT(model->nu, 0);
|
|
|
|
// actuators are ordered in pairs with actearly=true and actearly=false
|
|
for (int i = 0; i < model->na / 2; i++) {
|
|
EXPECT_TRUE(model->actuator_actearly[2*i]);
|
|
EXPECT_FALSE(model->actuator_actearly[2*i + 1]);
|
|
}
|
|
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// set all controls to the same value and make one step
|
|
mju_fill(data->ctrl, 0.5, model->nu);
|
|
mj_step(model, data);
|
|
|
|
for (int i = 0; i < model->na / 2; i++) {
|
|
EXPECT_EQ(data->act[2 * i], data->act[2 * i + 1])
|
|
<< "act should be the same after first step for "
|
|
<< mj_id2name(model, mjOBJ_ACTUATOR, 2 * i);
|
|
|
|
EXPECT_EQ(data->act_dot[2 * i], data->act_dot[2 * i + 1])
|
|
<< "act_dot should be the same after first step for "
|
|
<< mj_id2name(model, mjOBJ_ACTUATOR, 2 * i);
|
|
}
|
|
|
|
for (int i = 0; i < 100; i++) {
|
|
std::vector<mjtNum> last_qfrc(data->qfrc_actuator,
|
|
data->qfrc_actuator + model->nu);
|
|
mj_step(model, data);
|
|
for (int j = 0; j < model->nu / 2; j++) {
|
|
// this is true for torque actuators
|
|
EXPECT_NEAR(last_qfrc[2 * j], data->qfrc_actuator[2 * j + 1], MjTol(1e-3, 1e-1))
|
|
<< "there should be a 1 step delay between qfrc for "
|
|
<< mj_id2name(model, mjOBJ_ACTUATOR, 2 * j);
|
|
}
|
|
}
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ActEarlyTest, DoesntChangeStateInMjForward) {
|
|
const std::string xml_path =
|
|
GetTestDataFilePath("engine/testdata/actuation/actearly.xml");
|
|
char error[1000];
|
|
mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// set all controls to the same value and make one step
|
|
mju_fill(data->ctrl, 0.5, model->nu);
|
|
mj_forward(model, data);
|
|
|
|
for (int i = 0; i < model->na; i++) {
|
|
EXPECT_EQ(data->act[i], 0)
|
|
<< "act should not change with mj_forward."
|
|
<< mj_id2name(model, mjOBJ_ACTUATOR, i);
|
|
}
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ActuatorTest, DisableActuator) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="slide" type="slide" axis="1 0 0"/>
|
|
<geom size="1" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<motor joint="slide" gear="2" group="0"/>
|
|
<position joint="slide" kp="1" group="1"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
data->ctrl[0] = 1.0;
|
|
data->ctrl[1] = 1.0;
|
|
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 3.0);
|
|
|
|
model->opt.disableactuator = 1 << 0;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 1.0);
|
|
|
|
model->opt.disableactuator = 1 << 1;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 2.0);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ActuatorTest, DisableActuatorOutOfRange) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="slide" type="slide" axis="1 0 0"/>
|
|
<geom size="1" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<actuator>
|
|
<motor joint="slide" gear="-1" group="-1"/>
|
|
<motor joint="slide" gear="5" group="0"/>
|
|
<motor joint="slide" gear="31" group="31"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
data->ctrl[0] = 1.0;
|
|
data->ctrl[1] = 1.0;
|
|
data->ctrl[2] = 1.0;
|
|
|
|
// all actuators active
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 35.0);
|
|
|
|
// set all bits of disableactuator, only group 1 is disabled
|
|
model->opt.disableactuator = ~0;
|
|
mj_forward(model, data);
|
|
EXPECT_EQ(data->qfrc_actuator[0], 30.0);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ActuatorTest, TendonActuatorForceRange) {
|
|
const std::string xml_path = GetTestDataFilePath(kTendonForceClamp);
|
|
mjModel* model = mj_loadXML(xml_path.c_str(), nullptr, nullptr, 0);
|
|
mjData* data = mj_makeData(model);
|
|
|
|
EXPECT_EQ(model->tendon_actfrclimited[0], 0);
|
|
EXPECT_EQ(model->tendon_actfrcrange[0], 0);
|
|
EXPECT_EQ(model->tendon_actfrcrange[1], 0);
|
|
|
|
EXPECT_EQ(model->tendon_actfrclimited[1], 1);
|
|
EXPECT_EQ(model->tendon_actfrcrange[2], -1);
|
|
EXPECT_EQ(model->tendon_actfrcrange[3], 1);
|
|
|
|
EXPECT_EQ(model->tendon_actfrclimited[2], 1);
|
|
EXPECT_EQ(model->tendon_actfrcrange[4], -10);
|
|
EXPECT_EQ(model->tendon_actfrcrange[5], 10);
|
|
|
|
EXPECT_EQ(model->tendon_actfrclimited[3], 1);
|
|
EXPECT_EQ(model->tendon_actfrcrange[6], 0);
|
|
EXPECT_EQ(model->tendon_actfrcrange[7], 1);
|
|
|
|
data->ctrl[0] = 1;
|
|
data->ctrl[1] = 1;
|
|
data->ctrl[2] = 1;
|
|
|
|
data->ctrl[3] = -1;
|
|
data->ctrl[4] = 1;
|
|
|
|
data->ctrl[5] = -20;
|
|
data->ctrl[6] = 5;
|
|
data->ctrl[7] = -5;
|
|
|
|
mj_forward(model, data);
|
|
|
|
EXPECT_NEAR(data->actuator_force[0], 1, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[1], 1, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[2], 1, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[3], -1, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[4], 1, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[5], -10, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[6], 5, 1e-6);
|
|
EXPECT_NEAR(data->actuator_force[7], -5, 1e-6);
|
|
|
|
EXPECT_EQ(data->sensordata[0], 3);
|
|
EXPECT_EQ(data->sensordata[1], 0);
|
|
EXPECT_EQ(data->sensordata[2], -10);
|
|
EXPECT_EQ(data->sensordata[3], 0);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// ----------------------------- actuator delays -------------------------------
|
|
|
|
TEST_F(ForwardTest, ActuatorDelay) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.01"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="slide" type="slide"/>
|
|
<geom size="0.1" mass="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="slide" delay="0.02" nsample="2"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// delay = 0.02 seconds, timestep = 0.01, so ndelay = ceil(0.02/0.01) = 2
|
|
EXPECT_EQ(model->actuator_history[0], 2);
|
|
|
|
// set ctrl to a nonzero value
|
|
data->ctrl[0] = 10.0;
|
|
|
|
// step once: the new ctrl is appended but won't be read for 2 timesteps
|
|
mj_step(model, data);
|
|
// actuator_force should still be 0 (delayed value from buffer init)
|
|
EXPECT_NEAR(data->actuator_force[0], 0.0, 1e-10);
|
|
|
|
// step again
|
|
mj_step(model, data);
|
|
// still reading old values
|
|
EXPECT_NEAR(data->actuator_force[0], 0.0, 1e-10);
|
|
|
|
// step a third time - now the delayed ctrl should arrive
|
|
mj_step(model, data);
|
|
// actuator_force should now be 10.0
|
|
EXPECT_NEAR(data->actuator_force[0], 10.0, 1e-10);
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// Test actuator delay with linear interpolation (interp=1)
|
|
// Uses delay = 1.5*timestep so interpolation is meaningful
|
|
TEST_F(ForwardTest, ActuatorDelayLinearInterp) {
|
|
constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option timestep="0.01"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="slide" type="slide"/>
|
|
<geom size="0.1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="slide" delay="0.015" nsample="3" interp="linear"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// delay = 0.015 seconds = 1.5*timestep, nsample=3, interp=1 (linear)
|
|
EXPECT_EQ(model->actuator_history[0], 3);
|
|
EXPECT_EQ(model->actuator_history[1], 1); // interp=1 (linear)
|
|
EXPECT_NEAR(model->actuator_delay[0], 0.015, MjTol(1e-10, 5e-6));
|
|
|
|
// Set increasing ctrl values
|
|
// Buffer has samples at times: -0.02, -0.01, 0 with values 0, 0, 0
|
|
// After step 0 at time=0.01: buffer has times -0.01, 0, 0.01 with values 0, 0, ctrl[0]
|
|
// Read at time 0.01 - 0.015 = -0.005: interpolate between t=-0.01 and t=0
|
|
// Since both values are 0, expected actuator_force = 0
|
|
|
|
data->ctrl[0] = 10.0;
|
|
mj_step(model, data);
|
|
EXPECT_NEAR(data->actuator_force[0], 0.0, MjTol(1e-10, 5e-6)) << "step 0";
|
|
|
|
// After step 1 at time=0.02: buffer has times 0, 0.01, 0.02 with values 0, 10, 20
|
|
// Read at time 0.02 - 0.015 = 0.005: interpolate between t=0 (val=0) and t=0.01 (val=10)
|
|
// Expected: 0 * 0.5 + 10 * 0.5 = 5
|
|
|
|
data->ctrl[0] = 20.0;
|
|
mj_step(model, data);
|
|
EXPECT_NEAR(data->actuator_force[0], 5.0, MjTol(1e-10, 5e-6)) << "step 1";
|
|
|
|
// After step 2 at time=0.03: buffer has times 0.01, 0.02, 0.03 with values 10, 20, 30
|
|
// Read at 0.03 - 0.015 = 0.015: interpolate between t=0.01 (val=10) and t=0.02 (val=20)
|
|
// Expected: 10 * 0.5 + 20 * 0.5 = 15
|
|
|
|
data->ctrl[0] = 30.0;
|
|
mj_step(model, data);
|
|
EXPECT_NEAR(data->actuator_force[0], 15.0, MjTol(1e-10, 5e-6)) << "step 2";
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
TEST_F(ForwardTest, FlexTrilinearInstability) {
|
|
// model parameters matches user's trilinear.xml
|
|
constexpr char xml[] = R"(
|
|
<mujoco model="stability_test">
|
|
<option gravity="0 0 -9.81" iterations="100" solver="CG" tolerance="1e-10"
|
|
timestep="0.002" integrator="implicitfast">
|
|
<flag warmstart="disable" island="disable"/>
|
|
</option>
|
|
<worldbody>
|
|
<geom name="floor" size="0 0 .05" type="plane" condim="3"/>
|
|
<flexcomp name="bed" type="grid" count="17 17 3" spacing="0.05 0.05 0.05"
|
|
pos="0 0 0.05" radius="0.0005" dim="3" mass="10" dof="trilinear">
|
|
<contact condim="3" solref="0.005 1" solimp=".99 .99 .001" selfcollide="none"/>
|
|
<elasticity young="865067.00" poisson="0.1" damping="1"/>
|
|
</flexcomp>
|
|
<body name="box" pos="0.05 0.05 0.5">
|
|
<freejoint/>
|
|
<geom name="box_geom" type="box" size="0.04 0.04 0.04" mass="0.5"
|
|
solref="0.001 1" solimp="0.99 0.99 0.01"/>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// flex stiffness sign checks
|
|
// verify correct sign of flex stiffness derivatives before simulation
|
|
int nv = model->nv;
|
|
mjtNum h = model->opt.timestep;
|
|
|
|
// create a test vector
|
|
std::vector<mjtNum> v(nv), Mv(nv), flex_Kv(nv);
|
|
for (int i = 0; i < nv; i++) v[i] = mju_Halton(i, 2) - 0.5;
|
|
mjtNum vnorm = mju_norm(v.data(), nv);
|
|
for (int i = 0; i < nv; i++) v[i] /= vnorm;
|
|
|
|
mj_forward(model, data);
|
|
|
|
// compute M*v and stiffness contributions
|
|
mj_mulM(model, data, Mv.data(), v.data());
|
|
|
|
// note: we use mjd_flexInterp_mulK here (unscaled by h^2) to check raw
|
|
// stiffness logic similar to what we expect in the solver now
|
|
mjtNum* v_copy = (mjtNum*)mju_malloc(nv * sizeof(mjtNum));
|
|
mju_copy(v_copy, v.data(), nv);
|
|
mju_zero(flex_Kv.data(), nv);
|
|
|
|
// using mulKD for legacy check consistency, but we know it applies h^2+h*d
|
|
// scaling; actually, let's stick to the high-level property checks from
|
|
// FlexStiffnessSign which used mulKD
|
|
mjd_flexInterp_mul(model, data, flex_Kv.data(), v.data(), h * h, h, NULL);
|
|
|
|
// compute v^T*M*v and v^T*scale*K*v
|
|
mjtNum vMv = mju_dot(v.data(), Mv.data(), nv);
|
|
// mulKD returns -scale*K*v, so -flex_Kv = +scale*K*v
|
|
mjtNum vKv = -mju_dot(v.data(), flex_Kv.data(), nv);
|
|
|
|
// assertions from FlexStiffnessSign
|
|
EXPECT_GT(vKv, 0) << "Stiffness contribution should be positive";
|
|
EXPECT_GT(vMv + vKv, vMv) << "Full Hessian should exceed M alone";
|
|
|
|
mju_free(v_copy);
|
|
|
|
// stability simulation
|
|
// run for steps to catch instability
|
|
for (int i = 0; i < 2000; ++i) {
|
|
mj_step(model, data);
|
|
|
|
for (int j = 0; j < model->nq; ++j) {
|
|
if (mju_abs(data->qpos[j]) > 1000.0) {
|
|
ADD_FAILURE() << "Instability detected at step " << i << " dof " << j
|
|
<< " val " << data->qpos[j];
|
|
return; // Exit early
|
|
}
|
|
}
|
|
}
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// Verify that flex damping does not affect rigid body motion
|
|
TEST_F(ForwardTest, FlexDampingRigidMotion) {
|
|
constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0" timestep="0.01" integrator="implicitfast"/>
|
|
<worldbody>
|
|
<flexcomp name="flex" type="grid" count="3 3 3" spacing="0.1 0.1 0.1"
|
|
pos="0 0 0" euler="45 45 45" radius="0.01" dim="3" mass="1" dof="trilinear">
|
|
<contact selfcollide="none"/>
|
|
<elasticity young="1e5" poisson="0.3" damping="10"/>
|
|
</flexcomp>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// Set initial rigid rotation velocity about Z axis
|
|
// Center of mass is roughly at 0 0 0 because pos="0 0 0" and symmetric grid.
|
|
// v = w x r. Let w = (1, 1, 1).
|
|
mjtNum w[3] = {10.0, 10.0, 10.0};
|
|
for (int i = 0; i < model->nv / 3; ++i) {
|
|
int qpos_adr = model->jnt_qposadr[i];
|
|
int qvel_adr = model->jnt_dofadr[i];
|
|
mjtNum* pos = data->qpos + qpos_adr;
|
|
mjtNum* vel = data->qvel + qvel_adr;
|
|
|
|
mjtNum r[3] = {pos[0], pos[1], pos[2]};
|
|
mju_cross(vel, w, r);
|
|
}
|
|
|
|
mj_forward(model, data);
|
|
mjtNum initial_energy = data->energy[0] + data->energy[1];
|
|
|
|
// Run a few steps
|
|
for (int i = 0; i < 10; ++i) {
|
|
mj_step(model, data);
|
|
}
|
|
|
|
mj_forward(model, data);
|
|
mjtNum final_energy = data->energy[0] + data->energy[1];
|
|
|
|
// Expect energy conservation.
|
|
// With the bug, damping force acts on rigid rotation, dissipating energy.
|
|
EXPECT_NEAR(final_energy, initial_energy, 1e-6 * initial_energy)
|
|
<< "Energy decayed significantly (" << initial_energy << " -> "
|
|
<< final_energy << ")";
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
// verify that implicit integrator respects parent-flex coupling
|
|
TEST_F(ForwardTest, FlexParentCoupling) {
|
|
static const char* const kXml = R"(
|
|
<mujoco>
|
|
<option integrator="implicit" timestep="0.01"/>
|
|
<worldbody>
|
|
<body name="parent" pos="0 0 0">
|
|
<freejoint/>
|
|
<geom size=".1" mass="0.1"/>
|
|
<flexcomp name="flex" type="grid" count="3 3 3" cellcount="1 1 1" spacing="1 1 1"
|
|
radius=".01" dim="3" mass="100" dof="trilinear" pos="1 1 1">
|
|
<contact selfcollide="none"/>
|
|
<elasticity young="1e4" poisson="0.3" damping="50"/>
|
|
</flexcomp>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
char error[1024];
|
|
mjModel* model = LoadModelFromString(kXml, error, sizeof(error));
|
|
ASSERT_THAT(model, NotNull()) << error;
|
|
mjData* data = mj_makeData(model);
|
|
|
|
// set state: parent moving, flex deformed
|
|
// this ensures both H_fp (coupling) and qacc_parent are non-trivial
|
|
// Run with Euler (timestep 1e-6)
|
|
model->opt.timestep = 1e-6;
|
|
model->opt.integrator = mjINT_EULER;
|
|
mj_resetData(model, data);
|
|
data->qvel[0] = 1.0;
|
|
data->qpos[7] += 0.01;
|
|
data->qfrc_applied[0] = 10000.0; // Apply large force to parent
|
|
mj_step(model, data); // Step integrates
|
|
std::vector<mjtNum> qvel_euler(model->nv);
|
|
mju_copy(qvel_euler.data(), data->qvel, model->nv);
|
|
|
|
// Run with Implicit (timestep 1e-6)
|
|
model->opt.integrator = mjINT_IMPLICIT;
|
|
mj_resetData(model, data);
|
|
data->qvel[0] = 1.0;
|
|
data->qpos[7] += 0.01;
|
|
data->qfrc_applied[0] = 10000.0;
|
|
mj_step(model, data); // Step integrates
|
|
std::vector<mjtNum> qvel_implicit(model->nv);
|
|
mju_copy(qvel_implicit.data(), data->qvel, model->nv);
|
|
|
|
// Check agreement
|
|
double max_diff = 0;
|
|
for (int i = 0; i < model->nv; ++i) {
|
|
double diff = mju_abs(qvel_euler[i] - qvel_implicit[i]);
|
|
if (diff > max_diff) max_diff = diff;
|
|
}
|
|
|
|
EXPECT_LT(max_diff, MjTol(2e-5, 1.5e-2))
|
|
<< "Implicit integrator should match Euler at small timestep";
|
|
|
|
mj_deleteData(data);
|
|
mj_deleteModel(model);
|
|
}
|
|
|
|
|
|
TEST_F(ForwardTest, TrilinearPinnedParentWithFreejoint) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option integrator="implicitfast"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint type="free"/>
|
|
<geom type="box" size="0.13 0.18 0.036" pos="0 0 0.036"/>
|
|
<body name="parent">
|
|
<flexcomp name="test" type="grid"
|
|
count="3 3 3" spacing=".1 .02 .1" radius="0.001"
|
|
pos="0 0 0.1" dof="trilinear" xyaxes="0 1 0 0 0 1" mass="10" dim="3">
|
|
<contact selfcollide="none"/>
|
|
<elasticity young="1e5" poisson="0.3" damping="0.1"/>
|
|
<pin id="0 2 4 6"/>
|
|
</flexcomp>
|
|
</body>
|
|
</body>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
std::array<char, 1024> error;
|
|
mjModel* m = LoadModelFromString(xml, error.data(), error.size());
|
|
ASSERT_THAT(m, NotNull()) << error.data();
|
|
mjData* d = mj_makeData(m);
|
|
|
|
int parent_id = mj_name2id(m, mjOBJ_BODY, "parent");
|
|
ASSERT_GT(parent_id, 0);
|
|
|
|
EXPECT_EQ(m->nflexnode, 8);
|
|
EXPECT_EQ(m->body_dofnum[parent_id], 0) << "parent body should have 0 DOFs";
|
|
|
|
int freejoint_body = m->body_parentid[parent_id];
|
|
EXPECT_EQ(m->body_dofnum[freejoint_body], 6) << "freejoint body has 6 DOFs";
|
|
|
|
mj_resetData(m, d);
|
|
mj_forward(m, d);
|
|
|
|
for (int i = 0; i < 500; i++) {
|
|
mj_step(m, d);
|
|
|
|
ASSERT_FALSE(mju_isBad(d->qpos[0]))
|
|
<< "Simulation became unstable at step " << i;
|
|
ASSERT_FALSE(mju_isBad(d->qvel[0]))
|
|
<< "Velocity became unstable at step " << i;
|
|
|
|
for (int j = 0; j < m->nq; j++) {
|
|
ASSERT_LT(mju_abs(d->qpos[j]), 100.0)
|
|
<< "Position exploded at step " << i << ", qpos[" << j
|
|
<< "]=" << d->qpos[j];
|
|
}
|
|
for (int j = 0; j < m->nv; j++) {
|
|
ASSERT_LT(mju_abs(d->qvel[j]), 1000.0)
|
|
<< "Velocity exploded at step " << i << ", qvel[" << j
|
|
<< "]=" << d->qvel[j];
|
|
}
|
|
}
|
|
|
|
mj_deleteData(d);
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
// -------------------- actuator damping and armature --------------------------
|
|
|
|
using ActuatorDampingTest = MujocoTest;
|
|
|
|
TEST_F(ActuatorDampingTest, SingleActuatorJointDamping) {
|
|
// actuator damping=3 with gear=2 should produce same force as
|
|
// joint damping=12 (3*2^2=12)
|
|
static constexpr char xml_actuator[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="2" damping="3"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
static constexpr char xml_joint[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"
|
|
damping="12"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m1 = LoadModelFromString(xml_actuator, error, sizeof(error));
|
|
ASSERT_THAT(m1, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m1);
|
|
|
|
mjModel* m2 = LoadModelFromString(xml_joint, error, sizeof(error));
|
|
ASSERT_THAT(m2, NotNull()) << error;
|
|
mjData* d2 = mj_makeData(m2);
|
|
|
|
mj_resetDataKeyframe(m1, d1, 0);
|
|
mj_forward(m1, d1);
|
|
|
|
mj_resetDataKeyframe(m2, d2, 0);
|
|
mj_forward(m2, d2);
|
|
|
|
EXPECT_EQ(d1->qfrc_passive[0], d2->qfrc_passive[0]);
|
|
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m1);
|
|
mj_deleteData(d2);
|
|
mj_deleteModel(m2);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, SingleActuatorTendonDamping) {
|
|
// actuator damping through tendon transmission
|
|
static constexpr char xml_actuator[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<tendon>
|
|
<fixed name="ten">
|
|
<joint joint="jnt" coef="1"/>
|
|
</fixed>
|
|
</tendon>
|
|
<actuator>
|
|
<motor tendon="ten" gear="2" damping="3"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
static constexpr char xml_tendon[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<tendon>
|
|
<fixed name="ten" damping="12">
|
|
<joint joint="jnt" coef="1"/>
|
|
</fixed>
|
|
</tendon>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m1 = LoadModelFromString(xml_actuator, error, sizeof(error));
|
|
ASSERT_THAT(m1, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m1);
|
|
|
|
mjModel* m2 = LoadModelFromString(xml_tendon, error, sizeof(error));
|
|
ASSERT_THAT(m2, NotNull()) << error;
|
|
mjData* d2 = mj_makeData(m2);
|
|
|
|
mj_resetDataKeyframe(m1, d1, 0);
|
|
mj_forward(m1, d1);
|
|
|
|
mj_resetDataKeyframe(m2, d2, 0);
|
|
mj_forward(m2, d2);
|
|
|
|
EXPECT_EQ(d1->qfrc_passive[0], d2->qfrc_passive[0]);
|
|
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m1);
|
|
mj_deleteData(d2);
|
|
mj_deleteModel(m2);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, SingleActuatorArmature) {
|
|
// actuator armature=0.5 with gear=3 should equal
|
|
// joint armature=4.5 (0.5*3^2=4.5)
|
|
static constexpr char xml_actuator[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="3" armature="0.5"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
static constexpr char xml_joint[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"
|
|
armature="4.5"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m1 = LoadModelFromString(xml_actuator, error, sizeof(error));
|
|
ASSERT_THAT(m1, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m1);
|
|
|
|
mjModel* m2 = LoadModelFromString(xml_joint, error, sizeof(error));
|
|
ASSERT_THAT(m2, NotNull()) << error;
|
|
mjData* d2 = mj_makeData(m2);
|
|
|
|
mj_resetDataKeyframe(m1, d1, 0);
|
|
mj_forward(m1, d1);
|
|
|
|
mj_resetDataKeyframe(m2, d2, 0);
|
|
mj_forward(m2, d2);
|
|
|
|
EXPECT_EQ(d1->qacc[0], d2->qacc[0]);
|
|
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m1);
|
|
mj_deleteData(d2);
|
|
mj_deleteModel(m2);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, MultipleActuatorsAccumulate) {
|
|
// two actuators: damping=2 gear=3, damping=1 gear=4
|
|
// equivalent joint damping: 2*9 + 1*16 = 34
|
|
static constexpr char xml_actuator[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="3" damping="2"/>
|
|
<motor joint="jnt" gear="4" damping="1"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
static constexpr char xml_joint[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"
|
|
damping="34"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m1 = LoadModelFromString(xml_actuator, error, sizeof(error));
|
|
ASSERT_THAT(m1, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m1);
|
|
|
|
mjModel* m2 = LoadModelFromString(xml_joint, error, sizeof(error));
|
|
ASSERT_THAT(m2, NotNull()) << error;
|
|
mjData* d2 = mj_makeData(m2);
|
|
|
|
mj_resetDataKeyframe(m1, d1, 0);
|
|
mj_forward(m1, d1);
|
|
|
|
mj_resetDataKeyframe(m2, d2, 0);
|
|
mj_forward(m2, d2);
|
|
|
|
EXPECT_EQ(d1->qfrc_passive[0], d2->qfrc_passive[0]);
|
|
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m1);
|
|
mj_deleteData(d2);
|
|
mj_deleteModel(m2);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, DampingSimulationEquivalence) {
|
|
// actuator damping=5 gear=2 should match joint damping=20 over time
|
|
static constexpr char xml_actuator[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -10"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="0 0 1"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="2" damping="5"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
static constexpr char xml_joint[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -10"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="0 0 1"
|
|
damping="20"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m1 = LoadModelFromString(xml_actuator, error, sizeof(error));
|
|
ASSERT_THAT(m1, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m1);
|
|
|
|
mjModel* m2 = LoadModelFromString(xml_joint, error, sizeof(error));
|
|
ASSERT_THAT(m2, NotNull()) << error;
|
|
mjData* d2 = mj_makeData(m2);
|
|
|
|
mj_resetDataKeyframe(m1, d1, 0);
|
|
mj_resetDataKeyframe(m2, d2, 0);
|
|
for (int i = 0; i < 100; i++) {
|
|
mj_step(m1, d1);
|
|
mj_step(m2, d2);
|
|
}
|
|
|
|
EXPECT_MJTNUM_EQ(d1->qpos[0], d2->qpos[0]);
|
|
EXPECT_MJTNUM_EQ(d1->qvel[0], d2->qvel[0]);
|
|
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m1);
|
|
mj_deleteData(d2);
|
|
mj_deleteModel(m2);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, ArmatureSimulationEquivalence) {
|
|
// actuator armature=2 gear=3 should match joint armature=18 over time
|
|
static constexpr char xml_actuator[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -10"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="0 0 1"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="3" armature="2"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
static constexpr char xml_joint[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -10"/>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="0 0 1"
|
|
armature="18"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<keyframe>
|
|
<key qvel="1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m1 = LoadModelFromString(xml_actuator, error, sizeof(error));
|
|
ASSERT_THAT(m1, NotNull()) << error;
|
|
mjData* d1 = mj_makeData(m1);
|
|
|
|
mjModel* m2 = LoadModelFromString(xml_joint, error, sizeof(error));
|
|
ASSERT_THAT(m2, NotNull()) << error;
|
|
mjData* d2 = mj_makeData(m2);
|
|
|
|
mj_resetDataKeyframe(m1, d1, 0);
|
|
mj_resetDataKeyframe(m2, d2, 0);
|
|
for (int i = 0; i < 100; i++) {
|
|
mj_step(m1, d1);
|
|
mj_step(m2, d2);
|
|
}
|
|
|
|
EXPECT_MJTNUM_EQ(d1->qpos[0], d2->qpos[0]);
|
|
EXPECT_MJTNUM_EQ(d1->qvel[0], d2->qvel[0]);
|
|
|
|
mj_deleteData(d1);
|
|
mj_deleteModel(m1);
|
|
mj_deleteData(d2);
|
|
mj_deleteModel(m2);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, UtilityFunctionValues) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="5" damping="7" armature="3"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
|
|
mjtNum poly[mjNPOLY] = {0};
|
|
EXPECT_EQ(mj_actuatorDamping(m, mjOBJ_JOINT, 0, poly), 175);
|
|
EXPECT_EQ(mj_actuatorArmature(m, mjOBJ_JOINT, 0), 75);
|
|
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
|
|
TEST_F(ActuatorDampingTest, NonlinearDamping) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<worldbody>
|
|
<body>
|
|
<joint name="jnt" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<motor joint="jnt" gear="3" damping="2 0.5 0.1"/>
|
|
</actuator>
|
|
</mujoco>
|
|
)";
|
|
char error[1024];
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
|
|
// linear damping: 2 * gear^2 = 18
|
|
mjtNum poly0[mjNPOLY] = {0};
|
|
EXPECT_EQ(mj_actuatorDamping(m, mjOBJ_JOINT, 0, poly0), 18);
|
|
|
|
// poly coefficients scaled by gear^2
|
|
mjtNum poly[mjNPOLY] = {0};
|
|
mj_actuatorDamping(m, mjOBJ_JOINT, 0, poly);
|
|
EXPECT_MJTNUM_EQ(poly[0], 0.5 * 9); // 4.5
|
|
EXPECT_MJTNUM_EQ(poly[1], 0.1 * 9); // 0.9
|
|
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
TEST_F(ActuatorDampingTest, DampingVsKvGearScaling) {
|
|
// Single model with two parallel bodies: one using kv, one using damping.
|
|
// Both produce the same joint-space damping force:
|
|
// kv: qfrc_actuator contribution = -kv * gear^2 * qvel
|
|
// damping: qfrc_passive contribution = -damping * gear^2 * qvel
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0" integrator="implicitfast"/>
|
|
<worldbody>
|
|
<body name="kv_body">
|
|
<joint name="jnt_kv" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
<body name="damp_body" pos="5 0 0">
|
|
<joint name="jnt_damp" type="slide" axis="1 0 0"/>
|
|
<geom size="1"/>
|
|
</body>
|
|
</worldbody>
|
|
<actuator>
|
|
<position joint="jnt_kv" kp="0" kv="5" gear="3"/>
|
|
<position joint="jnt_damp" kp="0" damping="5" gear="3"/>
|
|
</actuator>
|
|
<keyframe>
|
|
<key qvel="1 1"/>
|
|
</keyframe>
|
|
</mujoco>
|
|
)";
|
|
|
|
char error[1024];
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
mjData* d = mj_makeData(m);
|
|
|
|
// check forces at initial state
|
|
mj_resetDataKeyframe(m, d, 0);
|
|
mj_forward(m, d);
|
|
|
|
// kv force arrives via qfrc_actuator, damping via qfrc_passive
|
|
mjtNum frc_kv = d->qfrc_actuator[0];
|
|
mjtNum frc_damp = d->qfrc_passive[1];
|
|
EXPECT_NEAR(frc_kv, frc_damp, MjTol(1e-12, 1e-5));
|
|
|
|
// expected force = -5 * 3^2 * 1 = -45
|
|
EXPECT_NEAR(frc_damp, -45, MjTol(1e-12, 1e-5));
|
|
|
|
// simulate and check trajectory equivalence
|
|
mj_resetDataKeyframe(m, d, 0);
|
|
for (int i = 0; i < 100; i++) {
|
|
mj_step(m, d);
|
|
}
|
|
|
|
EXPECT_NEAR(d->qpos[0], d->qpos[1], MjTol(1e-12, 1e-5))
|
|
<< "position trajectory mismatch";
|
|
EXPECT_NEAR(d->qvel[0], d->qvel[1], MjTol(1e-12, 1e-5))
|
|
<< "velocity trajectory mismatch";
|
|
|
|
mj_deleteData(d);
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
// flex sheet dropping on a plane should not gain energy from implicit bending
|
|
TEST_F(ImplicitIntegratorTest, FlexContactEnergy) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 -10" timestep="0.001" integrator="implicitfast"
|
|
solver="CG" tolerance="1e-6">
|
|
<flag energy="enable"/>
|
|
</option>
|
|
<default>
|
|
<geom solref="0.003 1"/>
|
|
</default>
|
|
<worldbody>
|
|
<geom type="plane" size="5 5 0.1"/>
|
|
<flexcomp type="grid" count="8 8 1" spacing=".04 .04 .04"
|
|
radius=".01" name="sheet" dim="2" pos="0 0 0.02" mass="0.1">
|
|
<edge equality="true" damping="0.1"/>
|
|
<elasticity young="3e6" poisson="0" thickness="2e-2"
|
|
elastic2d="bend" damping="0"/>
|
|
<contact solref="0.003 1" internal="false" selfcollide="none"/>
|
|
</flexcomp>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
char error[1024] = {0};
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
ASSERT_EQ(m->nflex, 1);
|
|
|
|
mjData* d = mj_makeData(m);
|
|
|
|
// compute initial energy
|
|
mj_forward(m, d);
|
|
mjtNum initial_energy = d->energy[0] + d->energy[1];
|
|
ASSERT_GT(initial_energy, 0);
|
|
|
|
// simulate
|
|
mjtNum max_energy = initial_energy;
|
|
int max_energy_step = 0;
|
|
int nsteps = 500;
|
|
for (int i = 0; i < nsteps; i++) {
|
|
mj_step(m, d);
|
|
mjtNum total_energy = d->energy[0] + d->energy[1];
|
|
if (total_energy > max_energy) {
|
|
max_energy = total_energy;
|
|
max_energy_step = i + 1;
|
|
}
|
|
}
|
|
|
|
mjtNum energy_ratio = max_energy / initial_energy;
|
|
|
|
EXPECT_LE(energy_ratio, 1.01)
|
|
<< "contact solver injected energy: max_energy/initial_energy = "
|
|
<< energy_ratio << " (max at step " << max_energy_step << ")"
|
|
<< "\n initial_energy = " << initial_energy
|
|
<< "\n max_energy = " << max_energy;
|
|
|
|
mj_deleteData(d);
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
// bending damping on a flat flex must dissipate energy with implicit integrator
|
|
TEST_F(ImplicitIntegratorTest, BendingDampingDecaysEnergy) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0" timestep="0.001" integrator="implicitfast">
|
|
<flag energy="enable"/>
|
|
</option>
|
|
<worldbody>
|
|
<flexcomp type="grid" count="6 6 1" spacing=".1 .1 .1"
|
|
radius=".005" name="sheet" dim="2" mass="0.1">
|
|
<edge equality="false" damping="0" stiffness="0"/>
|
|
<elasticity young="1e6" poisson="0" thickness="0.02"
|
|
elastic2d="bend" damping="0.1"/>
|
|
<contact solref="0.01" internal="false" selfcollide="none"/>
|
|
</flexcomp>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
char error[1024] = {0};
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
ASSERT_EQ(m->nflex, 1);
|
|
ASSERT_GT(m->flex_damping[0], 0) << "flex_damping not set";
|
|
|
|
mjData* d = mj_makeData(m);
|
|
|
|
// perturb a central vertex with upward velocity
|
|
// vertex layout is 6x6 grid; pick a central vertex (row=3, col=3 -> id=21)
|
|
int center_vert = 21;
|
|
int bid = m->flex_vertbodyid[m->flex_vertadr[0] + center_vert];
|
|
int dofadr = m->body_dofadr[bid];
|
|
d->qvel[dofadr + 2] = 1.0; // z-velocity
|
|
|
|
// initial forward to compute energy
|
|
mj_forward(m, d);
|
|
mjtNum initial_energy = d->energy[0] + d->energy[1];
|
|
ASSERT_GT(initial_energy, 0) << "initial energy should be nonzero";
|
|
|
|
// step forward and check energy decay
|
|
mjtNum max_energy = initial_energy;
|
|
int nsteps = 100;
|
|
for (int i = 0; i < nsteps; i++) {
|
|
mj_step(m, d);
|
|
mjtNum total_energy = d->energy[0] + d->energy[1];
|
|
max_energy = mju_max(max_energy, total_energy);
|
|
}
|
|
|
|
// energy must never exceed initial (system must not go unstable)
|
|
EXPECT_LE(max_energy, initial_energy * 1.01)
|
|
<< "energy exceeded initial by more than 1%: max=" << max_energy
|
|
<< ", initial=" << initial_energy;
|
|
|
|
// after 100 steps (0.1 seconds), energy should have decayed significantly
|
|
mjtNum final_energy = d->energy[0] + d->energy[1];
|
|
EXPECT_LT(final_energy, 0.5 * initial_energy)
|
|
<< "energy did not decay by at least 50% after " << nsteps << " steps"
|
|
<< " (initial=" << initial_energy << ", final=" << final_energy << ")";
|
|
|
|
mj_deleteData(d);
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
// interp stretch stiffness with implicitfast must preserve energy stability
|
|
TEST_F(ImplicitIntegratorTest, InterpStretchEnergy) {
|
|
static constexpr char xml[] = R"(
|
|
<mujoco>
|
|
<option gravity="0 0 0" timestep="0.001" integrator="implicitfast">
|
|
<flag energy="enable"/>
|
|
</option>
|
|
<worldbody>
|
|
<flexcomp type="grid" count="4 4 4" cellcount="3 3 3"
|
|
spacing=".05 .05 .05" radius=".005" name="cube"
|
|
dim="3" mass="10" dof="trilinear">
|
|
<elasticity young="1e6" poisson="0.3" damping="0"/>
|
|
<contact selfcollide="none" internal="false"/>
|
|
</flexcomp>
|
|
</worldbody>
|
|
</mujoco>
|
|
)";
|
|
|
|
char error[1024] = {0};
|
|
mjModel* m = LoadModelFromString(xml, error, sizeof(error));
|
|
ASSERT_THAT(m, NotNull()) << error;
|
|
|
|
mjData* d = mj_makeData(m);
|
|
|
|
// perturb a central vertex with velocity
|
|
int center_body = m->nbody / 2;
|
|
int dofadr = m->body_dofadr[center_body];
|
|
ASSERT_GT(m->body_dofnum[center_body], 0);
|
|
d->qvel[dofadr + 2] = 1.0; // z-velocity
|
|
|
|
mj_forward(m, d);
|
|
mjtNum initial_energy = d->energy[0] + d->energy[1];
|
|
ASSERT_GT(initial_energy, 0) << "initial energy should be nonzero";
|
|
|
|
// step and track max energy
|
|
mjtNum max_energy = initial_energy;
|
|
int nsteps = 50;
|
|
for (int i = 0; i < nsteps; i++) {
|
|
mj_step(m, d);
|
|
mjtNum total_energy = d->energy[0] + d->energy[1];
|
|
max_energy = mju_max(max_energy, total_energy);
|
|
}
|
|
|
|
// energy must not blow up
|
|
EXPECT_LE(max_energy, initial_energy * 1.01)
|
|
<< "energy exceeded initial by more than 1%: max=" << max_energy
|
|
<< ", initial=" << initial_energy;
|
|
|
|
mj_deleteData(d);
|
|
mj_deleteModel(m);
|
|
}
|
|
|
|
} // namespace
|
|
} // namespace mujoco
|