I have an axle testing system (detailed in another topic on the forum) that is driven and loaded with hydraulic motors through gearboxes, one on each corner of the axle being tested (3 total). The test stand will run testing cycles of various speed/torque points at each gearbox, switching between speed (velocity) and torque (force) limiting control modes as the cycle executes. Each gearbox has an encoder for speed feedback and torque feedback at the gearbox output.
All of the position/force examples I have seen have been of linear axes so I am not sure how to implement the force limit with my system. Being that this system can spin indefinitely, position is not relevant for us, except for calculating velocity.
The intended mode of operation was to send a velocity command, along with a force limit per corner, and allow the system to switch in and out of velocity or force limit control as the speeds and loads on each corner change throughout the cycle. Corners trying to stop rotation would be issued a 0 velocity command with a force limit matching the desired load. Then if load was removed, the velocity would be controlled to zero, versus running away as with force control.
How would I go about programming the switching in and out of force limit mode?