I’m trying to simulate the clearpath husky robot in ISAAC Sim. I add a flat terrain and give wheel velocities of 374 deg/s (right) and 181.4 (left). Which corresponds to v = 0.8 m/s and omega as 1 rad/s. It should have an ICR as 0.8 m but instead it traces an extremely large circle (33m or something). Stiffness is zero and damping is set to 100000.
Is there some setting I’m missing? Attaching the urdf as well.
husky.urdf (12.3 KB)
Does anybody have an idea about this?
Attaching the video with both solvers.
In PGS solver, it behaves better for tracing a circle of a specified radius but does not work properly when opposite velocities are given to the wheels. When using TGS, it does not work either way. Attaching the video for rotation about its axis.
I was able to get a consistent behavior after making a few tweaks on the solver and model:
with the velocities of [181, 374] for left and right wheels
Solver - Critical point is Enable CCD, make sure friction type is set to Patch, and increase time steps per second to 600 (I was able to get it working with 360, but sometimes it would slip):
- Ensure the robot Mass and center of Mass are in the right location
- Enable CCD to all Wheels
- Add a Physics material to the Wheels colliders:
Those adjustments also allowed the robot to turn in place
@rgasoto Thank you so much. It works but w.r.t rotating on the spot, it gives a very bumpy motion. Have you experienced the same?
I have not… can you share your current usd model so i can take a look? Please send a collected folder to avoid any missing reference. (To collect click in file, save collected as)
@rgasoto , were you able to replicate the issue?