Let's say I have an industrial sized 6DOF robotic arm. I want to control each one of the six joints despite the non-linearity produced by the chain structure, the gravity and the weight of the loads it could lift.
I don't focus here on the speed nor the power limitations, I just want the arm to respond well. Moreover, I would like to avoid the use of any prior knowledge such as inertial computation. Then I had these considerations, considering that I can play with both the actuator design, and the loop feedback control system:
- Limit the maximum speed of each actuator to smooth their error variation.
- Increase the damping of the actuators to avoid high frequency instability.
- Find a good control system, such as a PID, to make sure the targets are reached without oscillations.
Do you have any other considerations in mind? Do you know what process(es) industrial designers follow?
EDIT: As it is said in the comments, my question concern the design of an adaptive controller for a robot arm, which is, how to design a joint control system (actuator + loop control) that don't need inertia and masses to be computed (the controller could adapt to its own structure, or to the loads it lifts). I'll be very much interested if you know some paper about adaptive control in the field of robotic arms.