Same force on symmetrical tendons don't cancel out

Omniverse Isaac Sim
1

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Isaac Sim Version

4.5.0

Operating System

Ubuntu 22.04

GPU Information

  • Model: RTX 4060
  • Driver Version: 550

Topic Description

Detailed Description

The set up includes four symmetrical tendons around one soft robot (simulated with chain of rigid bodies connected with joints, inspired by the rope example). The four tendons all have an offset to the capsules. When I apply equal force on all tendons, I expect the soft robot to stay straight and not move, but it moves and bends. What should I tune to achieve the desired outcome?
I’ve attached the scene script.

Screenshots or Videos

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forum.zip (5.6 KB)

2

I solved it by tuning some parameters. Isaac sim doesn’t work well with small and light weight objects.

4

Hi @haoyun1, thank you for posting your issue. If objects are very light weight the physics solver won’t be able to perform well due to very high speeds of rigid bodies. One option like you said is to increase the inertial parameters, the other option is to reduce to physics time step. You can do that in the properties of PhysicsScene Prim > Time Steps Per Second. Increase the number to like 240, 360 or more.