Yuval Tassa
6a85b5db45
Significantly reduced joint-level damping, introduced damping in the actuators themselves. This reduces dynamics artifacts by matching the space in which damping and actuation forces are applied. PiperOrigin-RevId: 509574523 Change-Id: Id99b69aea4562509c48ed1a24fb9ea3e008c0b69
63 lines
2.6 KiB
XML
63 lines
2.6 KiB
XML
<mujoco>
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<compiler autolimits="true"/>
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<!--
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Adding a high fluid viscosity and using implicit integration for extra stabillity.
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Extra stabillity is required because the abstract "arm" model is not very realistic.
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(e.g. 4 consecutive ball joints is not a realistic kinematic design)
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-->
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<option viscosity="10" integrator="implicit">
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<flag gravity="disable" contact="disable"/>
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</option>
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<statistic meansize=".05"/>
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<default>
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<default class="translation">
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<general gainprm="100" biasprm="0 -100 -10" biastype="affine" ctrlrange="-.25 .25"/>
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</default>
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<default class="rotation">
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<!--
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Note that the rotational control range is purposefully limited to (-pi/2, pi/2) to avoid the
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documented instabillity near pi, which is due to taking quaternion differences.
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Increase this range to pi or bigger in order to see the instabillity.
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See here for more details https://mujoco.readthedocs.io/en/latest/XMLreference.html#actuator
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-->
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<general gainprm=".5" biasprm="0 -.5 -.05" biastype="affine" ctrlrange="-1.571 1.571"/>
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</default>
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<joint damping="1e-4"/>
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<site type="box" size=".012 .012 .012" rgba=".7 .7 .8 1"/>
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</default>
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<worldbody>
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<light pos="0 0 2"/>
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<geom type="box" size=".25 .25 .01" pos="0 0 -.01"/>
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<site name="reference" pos="0 0 .25"/>
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<body name="arm" pos="-.25 .25 0">
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<joint type="ball"/>
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<geom type="box" size=".01" fromto="0 0 0 0 0 .25"/>
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<body pos="0 0 .25">
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<joint type="ball"/>
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<geom type="box" size=".01" fromto="0 0 0 .25 0 0"/>
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<body pos=".25 0 0">
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<joint type="ball"/>
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<geom type="box" size=".01" fromto="0 0 0 0 -.2 0"/>
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<body pos="0 -.2 0">
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<joint type="ball"/>
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<geom type="box" size=".01" fromto="0 0 0 0 -.05 0"/>
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<site name="end_effector" pos="0 -.05 0"/>
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</body>
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</body>
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</body>
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</body>
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</worldbody>
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<actuator>
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<general name="x" site="end_effector" refsite="reference" gear="1 0 0 0 0 0" class="translation"/>
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<general name="y" site="end_effector" refsite="reference" gear="0 1 0 0 0 0" class="translation"/>
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<general name="z" site="end_effector" refsite="reference" gear="0 0 1 0 0 0" class="translation"/>
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<general name="rx" site="end_effector" refsite="reference" gear="0 0 0 1 0 0" class="rotation"/>
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<general name="ry" site="end_effector" refsite="reference" gear="0 0 0 0 1 0" class="rotation"/>
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<general name="rz" site="end_effector" refsite="reference" gear="0 0 0 0 0 1" class="rotation"/>
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</actuator>
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</mujoco>
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