Ackermann based robot by python script

Hi, I’m working on python script to import ‘robot.usd’ using Isac sim.

[Pre-knowledge]
I’m going to use a total of 2 robot models. The urdf model of each robot was downloaded through the git hub link marked with urdf link, converted to usd through the UrdF Importer of Isac sim, and saved it.

(I saved the robot usd after import URDF → unparent → set as default prim ->set articulation root → save)

[main quesiton]

The problem is that the Simulation APP is suddenly shut down when the code is executed.
Below is the code for me to call Qcar.

  1. Please let me know why the above phenomenon occurs.
  2. Currently I’m guessing that the two models are Ackermann-based models so they don’t get called ‘WheeledRobot’. If this is the real reason, I’d like to know how to get them as a model python script.