xArm7 Gripper can't Grasp Objects - Githubissues

google-deepmind / mujoco_menagerie

A collection of high-quality models for the MuJoCo physics engine, curated by Google DeepMind.

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xArm7 Gripper can't Grasp Objects #83

Open jonzamora opened 1 month ago

jonzamora commented 1 month ago

Which model is the issue affecting?

xArm7

What is the issue?

I'm working on a task where an xArm7 can grasp and lift a cube with the help of mink, however, I ran into an issue with the gripper.

https://github.com/user-attachments/assets/a3200082-b9ba-478d-b977-4c763f023c6f

Could someone help me debug the xArm7 gripper so it can grasp the cube properly?

I tried all the suggestions mentioned in https://github.com/google-deepmind/mujoco/issues/786 and https://github.com/google-deepmind/mujoco_menagerie/issues/54, though my attempts were unsuccessful so far.

Is there any additional context you can provide (e.g., a spec sheet or a URDF to show a value mismatch)?

My code can be found here https://github.com/jonzamora/mink.
To reproduce the video above, simply run mjpython examples/arm_xarm7.py

kevinzakka commented 1 month ago

I don't have a lot of bandwidth to fix this right now, but some things that can be done to improve this gripper:

Custom geom colliders for the finger pads, like in the Robotiq model. Splitting into 2 boxes per pad for more contacts is even better.
Adding <option cone="elliptic" impratio="10"/>.
The forcerange on the gripper actuator seems excessively high (100 N?)
Adding armature to the joints as was done with the Robotiq model for a bit more stability.