Is it possible to control D6 joint with action graph

Omniverse Isaac Sim
1

I’m trying to control D6 joint with action graph which is connected to my ROS2 script. But I’m getting following error
2024-08-20 02:16:14 [4,862,420ms] [Error] [omni.physx.tensors.plugin] Provided pattern list did not match any articulations

I’ve done it with RevoluteJoint just fine. But not working with D6 joint

2

Hi, I’m sorry that I cannot help. I’m facing similar issue and wanted to ask if you have solved it?

3

I don’t think you can control D6 or spherical joints directly. I can tell you for sure that D6 and spherical joints are not supported in the articulation APIs.

What are you trying to do? Real robots don’t really have D6 or spherical actuators. I see this question pop up from time to time and there’s usually a way to model what’s needed with revolute and prismatic joints.

4

I have a specialized robot that uses a 3PSP setup, which creates a closed-loop system. As shown in this post: Parallel Robot similar to Stewart platform physx issue - #2 by VickNV, I struggled with this issue. After that, I forced everything through direct USD transform via Python script, which resulted in not using the PhysX Engine at all and caused significant lag.

Later, someone suggested I should try to recreate the robot using available joints that could mimic the 3PSP setup, and I developed a 2xD6Joint system. Isaac Sim immediately warned me that the 3 linear axes had to be blocked for the articulation to even run, so I used 2 prismatic joints and just the two rotational axes (X and Y) of the 6DJoints. I’ve been waiting for an answer on how to drive a D6Joint for a month since I received no warning from Isaac Sim.

And now you tell me it’s not possible! So I will abandon that idea and use two rotational joints instead.

Thanks you very much for the Insight :)