Yuval Tassa
efae9157a7
PiperOrigin-RevId: 884607673 Change-Id: If8088dbf37fed1055304778a7eb84dec52cba920
90 lines
2.9 KiB
XML
90 lines
2.9 KiB
XML
<mujoco model="Polynomial Stiffness">
|
|
<!--
|
|
Four boxes hanging from spatial tendons, demonstrating polynomial stiffness.
|
|
Each tendon has a different stiffness profile:
|
|
1. Linear: k(q) = a*q (stiffness="100 0 0")
|
|
2. Quadratic: k(q) = b*q^2 (stiffness="0 200 0")
|
|
3. Cubic: k(q) = c*q^3 (stiffness="0 0 300")
|
|
4. Combination: k(q) = a*q + b*q^2 + c*q^3 (stiffness="100 -400 400")
|
|
-->
|
|
|
|
<visual>
|
|
<map force="0.1" zfar="30"/>
|
|
<rgba haze="0.15 0.25 0.35 1"/>
|
|
<global offwidth="1280" offheight="720" elevation="-10"/>
|
|
</visual>
|
|
|
|
<asset>
|
|
<texture type="skybox" builtin="gradient" rgb1="0.3 0.5 0.7" rgb2="0 0 0" width="32" height="32"/>
|
|
<texture name="grid" type="2d" builtin="checker" rgb1=".2 .3 .4" rgb2=".1 .15 .2" width="512" height="512"/>
|
|
<material name="grid" reflectance="0.3" texture="grid" texrepeat="5 5" texuniform="true"/>
|
|
</asset>
|
|
|
|
<default>
|
|
<geom condim="3"/>
|
|
<site rgba="0 .8 0 .5" size=".03"/>
|
|
<tendon width=".01" rgba=".9 .9 .9 1" springlength="0 .3"/>
|
|
<default class="box">
|
|
<geom type="box" size=".2 .2 .2" mass="5"/>
|
|
</default>
|
|
</default>
|
|
|
|
<worldbody>
|
|
<geom type="plane" size="3 3 .01" material="grid"/>
|
|
<light directional="true" diffuse=".4 .4 .4" specular="0 0 0" pos="0 0 5" dir="0 0 -1" castshadow="false"/>
|
|
<light directional="false" diffuse=".8 .8 .8" specular=".3 .3 .3" pos="0 -2 4" dir="0 .5 -1"/>
|
|
|
|
<!-- anchor sites -->
|
|
<site name="anchor_linear" pos="-1.5 0 2"/>
|
|
<site name="anchor_quadratic" pos="-.5 0 2"/>
|
|
<site name="anchor_cubic" pos=".5 0 2"/>
|
|
<site name="anchor_combi" pos="1.5 0 2"/>
|
|
|
|
<body name="linear" pos="-1.5 0 1.5">
|
|
<freejoint/>
|
|
<geom class="box" rgba=".2 .6 1 1"/>
|
|
<site name="hook_linear" pos="0 0 .2"/>
|
|
</body>
|
|
|
|
<body name="quadratic" pos="-.5 0 1.5">
|
|
<freejoint/>
|
|
<geom class="box" rgba="1 .4 .1 1"/>
|
|
<site name="hook_quadratic" pos="0 0 .2"/>
|
|
</body>
|
|
|
|
<body name="cubic" pos=".5 0 1.5">
|
|
<freejoint/>
|
|
<geom class="box" rgba=".2 .8 .2 1"/>
|
|
<site name="hook_cubic" pos="0 0 .2"/>
|
|
</body>
|
|
|
|
<body name="combi" pos="1.5 0 1.5">
|
|
<freejoint/>
|
|
<geom class="box" rgba=".8 .2 .8 1"/>
|
|
<site name="hook_combi" pos="0 0 .2"/>
|
|
</body>
|
|
</worldbody>
|
|
|
|
<tendon>
|
|
<spatial name="linear" stiffness="100">
|
|
<site site="anchor_linear"/>
|
|
<site site="hook_linear"/>
|
|
</spatial>
|
|
|
|
<spatial name="quadratic" stiffness="0 200">
|
|
<site site="anchor_quadratic"/>
|
|
<site site="hook_quadratic"/>
|
|
</spatial>
|
|
|
|
<spatial name="cubic" stiffness="0 0 300">
|
|
<site site="anchor_cubic"/>
|
|
<site site="hook_cubic"/>
|
|
</spatial>
|
|
|
|
<spatial name="combination" stiffness="100 -400 400">
|
|
<site site="anchor_combi"/>
|
|
<site site="hook_combi"/>
|
|
</spatial>
|
|
</tendon>
|
|
</mujoco>
|