[Question] Custom UR3 with Robotiq 2f-140 instability

[ZachAtkins0n]

I'm using a custom usd file with a UR3 robot arm and Robotiq 2F-140 gripper using the assembler function in IsaacSim.
When I use this for any reinforcement learning tasks with the robot is unstable which causes the value function loss to exponentially grow.
I'm not sure if it is because of the usd file itself or something else. Any help will be appreciated.

Link to usd file:
https://drive.google.com/drive/folders/1chWPzIpIeduMP-0AUxyvLv0MNCVKrktF?usp=sharing

[ZachAtkins0n]

I've modified the positions of the robot arm to reduce clipping however joint vel fluctuates with the reward alternating between a small number or exponentially tiny as shown in the image. I'm using the manager based lift environment using rsl_rl with the custom UR3 robot

Further runs show that the gripper arm is folding into itself as well

[ZachAtkins0n]

After a lot of testing it does seem that the cause is the robotiq gripper. When teleoperating the robot I've noticed that the gripper will collapse into itself depending on the open and close parameters. Furthermore, with teleoperation, I've been successful in picking the cube so I wonder if imitation learning should be better approach for such a task like this?

[martinmatak]

have you fixed the gripper? do you have a working USD of it?

[RandomOakForest]

Thank you for posting this. I'll move the post to our Discussions section for the team to follow up.

[ZachAtkins0n]

UPDATE:
It seems that the velocity of the robot arm was a major factor that caused the robotiq arm to clip into itself and in turn cause the training process to become unstable. Limiting the velocity in the config file appears to resolve the instability issue.

[ZachAtkins0n]

UPDATE 2:

Good news, I've managed to resolve the issue and successfully have the robot pick the block and lift it now. This issue was down to the velocity limit of the UR3 being too fast which caused the robotiq gripper to clip into itself.