A differential drive robot with casters exhibits significant bouncing while driving

Omniverse Isaac Sim
1

Isaac Sim Version

4.5.0

Operating System

Windows 11

GPU Information

  • Model: NVIDIA GeForce RTX 4070 Laptop GPU

  • Driver Version: 570.124.03

Topic Description

A differential drive robot with casters exhibits significant bouncing while driving.

Detailed Description

image_1

As shown above, a differential drive robot exhibits significant bouncing while driving.

The large central wheels are the drive wheels, and no Drive is applied to the four corner casters.

When the Z-axis rotation of the caster joints is fixed, the issue no longer occurs, suggesting that the Z-axis rotation is likely the cause.

This phenomenon can be somewhat mitigated by:

  • Adjusting the mass values
  • Modifying the size or connection position of the wheels
  • Increasing the resolution (granularity) of the physics simulation

However, even slight changes can cause the issue to reappear. The resulting motion is also physically extreme and appears somewhat unnatural.

We would appreciate any insight as to whether this behavior is an inherent characteristic of Isaac Sim’s physics simulation, or if it can be resolved through parameter tuning or other means.

3

Hi @ochigc, Thank you for posting your issue. That is a very strange behavior. What you have tried is also what I would suggest. Can you share the script or USD you are using to create this scene?

4

Hi @michalin
Thank you for your reply.
I’ve attached a sample that reproduces the issue.
You can control the vehicle using the W/A/S/D keys.

sample.zip (8.1 KB)