hello i wonder how to control parallel (closed chain) gripper.
I found two similar questions on the forum.
Link 1 moves with the gripper’s joint separated.
Link 2 moves as the gripper successfully forms a closed chain.
Link 1 : https://forums.developer.nvidia.com/t/add-gripper-to-ur5e/174647/2\
Link 2 : Robotiq 2f-140 gripper not moves smoothly - #6 by rgasoto
Can you tell me how to move like link 2?
I looked at the tutorial below and couldn’t find an answer.
ur5_rg2.zip (4.0 MB)
This zip file is my manipulator and gripper, please take a look.
@hoe8279 - This document about the gripper in the most recent Isaac Sim release will be useful to you Surface Gripper — Omniverse IsaacSim latest documentation
Hello! There’s not much more to do when controlling a closed loop joint. In the case of the gripper, it currently has individual controller for the fingers - You’d need to add a Tendon to control with an individual action value, but we currently recommend doing a dual value (one for each finger) for performance and stability reasons.
Now, regarding the finger simulation for the closed loop - You’d need to pick one of the joints of the loop and check “Exclude from Articulation” - This lets the Articulation Schema to be used with no problems.
Move all joint damping properties from the excluded joint to the ones that were not excluded from articulation, since they are solved with a better stabilization algorithm, while the “Excluded from Articulation” joint will be solved at a best effort measure (it will still converge to the right pose, but the stabilization is prioritized to the other ones. For example if it reaches an unreachable solution that will be the first joint to break position to satisfy the solver).