Datasets:

introvoyz041
/

mujoco

	<mujoco model="Active adhesion example">
	<!--
	Adding some fluid viscosity to prevent the hanging sphere from jiggling too much.
	-->
	<option viscosity="1"/>

	<size memory="10M"/>

	<visual>
	<headlight diffuse=".2 .2 .2"/>
	</visual>

	<default>
	<joint damping=".3" axis="0 1 0"/>
	<geom type="box" friction=".5"/>
	<default class="wall">
	<geom rgba=".5 .5 .5 .4"/>
	</default>
	<default class="mechanical">
	<geom rgba=".5 .5 .8 1"/>
	<tendon rgba=".5 .5 .8 1"/>
	</default>
	<default class="active_adhesion">
	<!--
	Geoms in the active_adhesion class are "inflated" with a margin of 1cm, but contacts are
	activated only at a depth gap of 1cm, leading to a layer of inactive contacts at a 1cm
	distance from the surface. However the contacts can be used by the adhesion actuator.
	-->
	<geom rgba=".8 .5 .5 1" margin=".01" gap=".01"/>
	</default>
	<default class="object">
	<geom rgba=".5 .8 .5 1" density="100"/>
	</default>
	</default>

	<worldbody>
	<light pos="0.4 -.15 .6" dir="-1 .5 -1" diffuse=".7 .7 .7"/>
	<light pos="-.4 -.15 .6" dir="1 .5 -1" diffuse=".7 .7 .7"/>

	<body name="two crates">
	<joint name="conveyor" type="slide" damping="100" axis="1 0 0"/>
	<geom size=".2 .1 .01" pos="0 0 -.01"/>
	<geom size=".01 .08 .031" pos="-.19 0 .03" class="wall"/>
	<geom size=".01 .08 .031" pos="0 0 .03" class="wall"/>
	<geom size=".01 .08 .031" pos="0.19 0 .03" class="wall"/>
	<geom size="0.2 .01 .031" pos="0 -.09 .03" class="wall"/>
	<geom size="0.2 .01 .031" pos="0 0.09 .03" class="wall"/>
	</body>

	<body name="arm1" pos="-.1 0 .3" childclass="mechanical">
	<joint name="arm1"/>
	<geom type="cylinder" size=".015 .01" zaxis="0 1 0"/>
	<geom type="capsule" size=".01" fromto="0 0 0 -.12 0 -.07"/>
	<body name="arm2" pos="-.12 0 -.07">
	<joint name="arm2"/>
	<geom type="cylinder" size=".015 .01" zaxis="0 1 0"/>
	<geom type="capsule" size=".01" fromto="0 0 0 .12 0 -.07"/>
	<body name="4boxes" pos=".12 0 -.08" childclass="active_adhesion">
	<site name="force_sensor" group="3"/>
	<joint name="arm3" damping=".01" pos="0 -.03 0"/>
	<geom size=".015 .015 .01" pos="0.015 0.015 0"/>
	<geom size=".015 .015 .01" pos="0.015 -.015 0"/>
	<geom size=".015 .015 .01" pos="-.015 0.015 0"/>
	<geom size=".015 .015 .01" pos="-.015 -.015 0"/>
	</body>
	</body>
	</body>

	<body name="box" pos="-.1 0 .05">
	<freejoint/>
	<geom size=".05 .05 .05" class="object"/>
	</body>

	<body name="winch" pos="-.01 0 .35" childclass="mechanical">
	<joint name="winch" damping="1"/>
	<geom type="cylinder" size=".015 .01" zaxis="0 1 0"/>
	<geom type="capsule" size=".01" fromto="0 0 0 .1 0 .05"/>
	<site name="anchor" pos=".1 0 .04"/>
	</body>
	<site name="pulley" pos=".1 0 .32"/>
	<site name="hook_left" pos=".08 0 .3"/>
	<site name="hook_right" pos=".12 0 .3"/>
	<body name="sphere" pos=".1 0 .2" childclass="active_adhesion">
	<freejoint/>
	<!--
	The composite balls in the crate have only 3 linear DoFs with condim=1, effectively
	frictionless point particles. In order to make them stick to the sphere we give the sphere
	priority 2, to force condim=3.

	Also note the sphere has a margin+gap of 3cm as opposed to the 1cm of the arm box.
	-->
	<geom type="sphere" size=".03" priority="2" margin=".03" gap=".03"/>
	<site name="pin_left" pos="-.025 0 .025"/>
	<site name="pin_right" pos=".025 0 .025"/>
	</body>

	<replicate count="4" offset=".025 0 0">
	<replicate count="4" offset="0 .025 0">
	<replicate count="4" offset="0 0 .025">
	<body pos=".06 -.04 .05">
	<joint type="slide" axis="1 0 0"/>
	<joint type="slide" axis="0 1 0"/>
	<joint type="slide" axis="0 0 1"/>
	<geom type="sphere" size=".012" rgba=".5 .8 .5 1" solref=".005 1" condim="1"/>
	</body>
	</replicate>
	</replicate>
	</replicate>
	</worldbody>

	<equality>
	<joint joint1="arm1" joint2="arm2" polycoef="0 -.5 0 0 0"/>
	<joint joint1="arm3" joint2="arm1"/>
	</equality>

	<!--
	By using divisor=3 in the pullies we increase the distance by which the hanging sphere moves
	relative to the motion of the winch arm. One should imagine a double spindle with two radii that
	creates a ratio of 1.5 between the motion of tendon before the pullies and after the pullies.
	(1.5 rather than 3 because the tendon has 2 branches and the length is split between them)
	-->
	<tendon>
	<spatial range="0 .19" limited="true" solreflimit=".01 2" class="mechanical">
	<site site="anchor"/>
	<site site="pulley"/>
	<pulley divisor="3"/>
	<site site="pulley"/>
	<site site="hook_left"/>
	<site site="pin_left"/>
	<pulley divisor="3"/>
	<site site="pulley"/>
	<site site="hook_right"/>
	<site site="pin_right"/>
	</spatial>
	</tendon>

	<actuator>
	<position name="conveyor" joint="conveyor" ctrlrange="-.2 .2" ctrllimited="true" kp="400"/>
	<position name="arm" joint="arm2" ctrlrange="-.8 1" ctrllimited="true" kp="10"/>
	<adhesion name="adhere_arm" body="4boxes" ctrlrange="0 1" gain="5"/>
	<position name="winch" joint="winch" ctrlrange="-.7 .5" ctrllimited="true" kp="10"/>
	<adhesion name="adhere_winch" body="sphere" ctrlrange="0 1" gain="5"/>
	</actuator>

	<sensor>
	<force site="force_sensor"/>
	</sensor>
	</mujoco>