How to create a custom explicit actuator that handles several joints at once ?

[vicltz]

I would like to create a custom explicit actuator that heritates from the ActuatorBase class (like the IdealPDActuator).

Each explicit actuator has a compute method (source here) that manages to compute the torque that is sent to the joint.

My need is the following: I would like to compute two output torques based on the angles of two joint angles (I cannot split the calculation).

Do you have any idea on how to do that ?

[RandomOakForest]

Thanks for posting this. Could you elaborate on what you mean with "compute two output torques" in a way that is not possible now? Currently, the compute call will process all torques from all joints.

[ozhanozen]

Hi @vicltz, if you need to actuate several joints at once, maybe, you need to create a controller rather than an actuator. What you can do for example is the following:

• Write a computation only controller class that calculates everything up to the joint torques/efforts. Have a look at this operational space controller as an example.
• The next step is to apply these torques to actuators/articulation. Since you will be calculating joint torques/efforts directly, you can use an ImplicitActuator (set the stiffness and damping to 0), and then use set_joint_effort_target to do this. If you are using a manager-based environment, one way to do this is to create an Action class doing this for you. See this as an example.

Hope that this helps.