Added MJCF file using position control instead of motor (torque) control #2
+983
−30
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
magdelinekuan
commented
Jul 16, 2025
magdelinekuan
commented
- Created a new MJCF file of the openarm bimanual robot that uses position control for each of the joints
- Modified joint limits according to those provided in the openarm_bimanual URDF
- Added forcerange according to peak torque specified in motor datasheets
- Added kp and damping to reduce overshoot and oscillations in simulation (may not reflect real values)
Add support for simulated openarm hardware with MuJoCo backend. Refactor the mujoco Move meshes to top level Add back the readme
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
Co-authored-by: Sutou Kouhei <kou@cozmixng.org> Update openarm_mujoco_hardware/include/openarm_mujoco_hardware/openarm_mujoco_hardware.hpp Co-authored-by: Sutou Kouhei <kou@cozmixng.org> Update openarm_mujoco_hardware/openarm_mujoco_hardware.xml Co-authored-by: Sutou Kouhei <kou@cozmixng.org> Update openarm_mujoco_hardware/package.xml Co-authored-by: Sutou Kouhei <kou@cozmixng.org> Update openarm_mujoco_hardware/test/test_load_openarm_mujoco_hardware.cpp Co-authored-by: Sutou Kouhei <kou@cozmixng.org> Update openarm_mujoco_hardware/src/openarm_mujoco_hardware.cpp Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
thomasonzhou
requested changes
Jul 19, 2025
Comment on lines
4
to
+6
| <default class="motor"> | ||
| <joint armature="0.001" frictionloss="0.1"/> | ||
| <motor ctrlrange="-0.2 0.2"/> | ||
| <motor ctrlrange="-0.2 0.2" gear="10"/> |
There was a problem hiding this comment.
It might be more worth it to add the damping property to the class here instead of repeating it below.
There was a problem hiding this comment.
Also, if we are updating gearing ratios, might as well also add armature:
https://mujoco.readthedocs.io/en/stable/XMLreference.html#body-joint-armature
| @@ -46,48 +48,48 @@ | |||
| <geom name="right_link1_collision" pos="0.0 0.0 0.0289" type="box" size="0.055 0.0365 0.0296" class="collision" /> | |||
| <geom name="right_link1_visual" pos="0.0 0.0 -0.0007" material="gray" type="mesh" mesh="link1.stl" class="visual" /> | |||
| <body name="right_link2" pos="0.0 0.0 0.05325"> | |||
| <joint name="right_rev1" type="hinge" class="motor" range="-2.0943951023931953 2.0943951023931953" axis="0 0 1" /> | |||
| <joint name="right_rev1" type="hinge" class="motor" damping="2.0" range="-2.0943951023931953 2.0943951023931953" axis="0 0 1" /> | |||
There was a problem hiding this comment.
also worth experimenting with: friction loss
https://mujoco.readthedocs.io/en/stable/XMLreference.html#body-joint-frictionloss
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.