I’m working on tuning a hub motor to use on a ground vehicle. Regarding only the FOC torque control loop, is it typically the case that tuning the motor unloaded gives the desired parameters in a loaded state? Or is retuning required for different loading?
Hey @field_twister , welcome to SimpleFOC!
So for a ground vehicle, depending also on the weight, friction and type of terrain it is sitting on, you will probably have to:
- perform the motor calibration in an unloaded state
- perform the tuning in the unloaded state to get a baseline
- re-tune in the loaded state if needed
You might also just tune in the loaded state, but finding the electrical zero will definately have to be in unloaded state unless your vehicle is so light and the ground so smooth that it causes very little load.
Thank you for the response! As a follow-up: For a vehicle which needs to handle a wide range of loads, what are the typical strategies to get smooth control over the entire range? Is some sort of MPC required so that the torque loop is dynamically tuned in response to the load?
I’m not really qualified to say… we’ve had some others here who have worked on rovers and even EV racecars, perhaps someone else can comment?
SimpleFOC only handles the low level control of the motor, but for a vehicle effective torque will also be about coordination of the wheels, detecting slip, etc. it will heavily depend on the design (differentials, 4WD with direct drive, etc)
Detecting stalls and thermal management will also be important aspects to work out.
So I think you’ll need some higher levels of control above SimpleFOC.