Parallel gripper not holding the box firmly enough

IsaacSim_parallel_gripper_object_slips.zip (9.4 MB)
Dear IsaacSim comminity,
I am working on a cardbox pick and place application with a Kinova link 6 robot and a parallel gripper (Robotiq 2f-140). After the robot closes the gripper and picks up the box the box slips from the gripper and falls down (even when the gripper is closed!) . You can see the described behaviour in the attached video. I have tried to increase the dynamic and static friction on both the gripper fingers material and box material. I also tried to modify the gripper joints closed position, so that they close fully and thus put more pressure on the box. However, the box still slips. Do you have any suggestions about the other parameters I can modify to prevent the objects from slipping from the gripper? Thank you in advance.
@rthaker

Hi, I’m having a similar issue, were you eventually able to solve the problem?

Hi @altick, unfortunately no. I will be grateful for your insight, @rthaker, @Morganh.

Hi, I think I found the solution in my case. Basically my gripper was defined with gains greater than zero and when I was trying to hold the object I was applying a force to the fingers with this function

gripper_articulation.apply_action(ArticulationAction(joint_position=CLOSE_POS, joint_efforts=np.array([1, 1]))

But following the docs I found out that for effort control your gains should be set to zero. So I removed the parameter joint_efforts=np.array([1, 1]) and it all worked out


Hope it helps