Collision spheres of Lula RMPflow

Omniverse Isaac Sim
1

Hi all,

I have created a YAML file for a UR10 robot using the Lula Robot Description Editor, with corresponding collision spheres for the robot.

If I now define the base position of the robot not at [0,0,0], but move the base position for example 1m in x direction [1.0, 0.0, 0.0] then the collision sphere does not longer match the robot (see image).

How can I realise the dependency of collision Sphere from the YAML file with the robot?

Many thanks for your help

Collision_Sphere_UR10.PNG
Collision_Sphere_UR10.PNG1253×832 65.4 KB

2

The collision spheres in the Lula Robot Description Editor are defined relative to the base frame of the robot. If you move the base position of the robot, the collision spheres should move with it. If they do not, it might be a bug or a misconfiguration in your YAML file.

Here are a few things you can check:

  1. Make sure that the base frame of the robot is correctly defined in the YAML file. The base frame should be the parent frame of all other frames in the robot.
  2. Make sure that the collision spheres are correctly defined in the YAML file. The position of each collision sphere should be defined relative to the base frame or another frame that is correctly linked to the base frame.
  3. Make sure that the transformation from the base frame to the world frame is correctly defined in the YAML file. This transformation should include the new base position of the robot.
  4. If you are using the Lula Robot Description Editor in a simulation or a visualization tool, make sure that the tool correctly interprets the YAML file and updates the position of the collision spheres when the base position of the robot changes.
3

Can you share me the YAML file and the usd and the main python script? In fact I am facing the same problem in a custom robot I have made.