Yuval Tassa
279df98cd0
<pid kp kv|dampratio [ki imax] [slewmax]> is a PID controller with real position and velocity setpoint inputs on a single force output, plus an optional feedforward input. With a zero velocity setpoint it reproduces <position> bit-exactly; the input signature is any subset of [pos, vel, ff], selected with input="..." and recorded as mjtCtrlInput bits in actuator_ctrlspec; absent setpoint inputs are fixed at zero, so the control vector contains no inert entries. kp and kv are single-sourced in the affine bias parameters (biasprm[1,2]) with no gainprm mirror: every consumer of the position-servo shape (dampratio conversion, inheritrange, qDeriv) reads one location, which is what makes the bit-exact <position> parity possible. Controller state uses dyntype 'pid' with slot-gated activations in the order [slew, integral], following the dcmotor slot idiom: slewmax (dynprm[1]) rate limits the effective position setpoint through an activation holding it; ki (gainprm[0]) integrates the position error -- wrapped on rotational transmissions -- with anti-windup clamping of the integrand at imax (dynprm[0]). Both features require the pos input. Servo input unpacking is shared with the dcmotor controller (unpackServoInputs); per-input ranges are exposed as posrange/velrange/ffrange. This subsumes the functionality of the mujoco.pid plugin with proper activation state: correct under all integrators, visible to keyframes, act sensors and reset. Migration: kp/ki/kd map to kp/ki/kv, plugin imax is in force units (divide by ki), slewmax carries over; the single ctrl becomes input="pos". PiperOrigin-RevId: 957588898 Change-Id: Id2786836ca6e76f58e5b5cc8323fc23be0a53784
MuJoCo Python Bindings
This package is the canonical Python bindings for the MuJoCo physics engine. These bindings are developed and maintained by Google DeepMind, and is kept up-to-date with the latest developments in MuJoCo itself.
The mujoco package provides direct access to raw MuJoCo C API functions,
structs, constants, and enumerations. Structs are provided as Python classes,
with Pythonic initialization and deletion semantics.
It is not the aim of this package to provide fully fledged
scene/environment/game authoring API, as there are already a number of existing
packages that do this well. However, this package does provide a number of
lower-level components outside of MuJoCo itself that are likely to be useful to
most users who access MuJoCo through Python. For example, the egl, glfw, and
osmesa subpackages contain utilities for setting up OpenGL rendering contexts.
Installation
The recommended way to install this package is via PyPI:
pip install mujoco
A copy of the MuJoCo library is provided as part of the package and does not need to be downloaded or installed separately.
Source
IMPORTANT: Building from source is only necessary if you are modifying the Python bindings (or are trying to run on exceptionally old Linux systems). If that's not the case, then we recommend installing the prebuilt binaries from PyPI.
If you need to build the Python bindings from source, please consult the documentation.
Usage
Once installed, the package can be imported via import mujoco. Please consult
our documentation for
further detail on the package's API.
We recommend going through the tutorial notebook which covers the basics of
MuJoCo using Python:
Versioning
The major.minor.micro portion of the version number matches the version of
MuJoCo that the bindings provide. Optionally, if we release updates to the
Python bindings themselves that target the same version of MuJoCo, a .postN
suffix is added, for example 2.1.2.post2 represents the second update to the
bindings for MuJoCo 2.1.2.
License and Disclaimer
Copyright 2022 DeepMind Technologies Limited
MuJoCo and its Python bindings are licensed under the Apache License, Version 2.0. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.
This is not an officially supported Google product.