It is "good enough" for PID output directly controls, without further modelling, the PWM duty cycle?
Logic behind the question is,
In case of pure resistance heater, PWM duty cycle percentage directly relates to power (on off time ratio). So, direct control is appropriate.
However, motor has two additional effects,
a) with considerable inductance, initial current is smaller and ramping up over time
b) as RPM gradually ramping up, after time constant of mechanical inertia etc, increasing back EMF will reduce current
Will it be wise to ignore the above two effects and still expect a reasonably good outcome?
Application is 6 volts, 2 watt DC brushed motor, gear 1:50, 10000 RPM no load, PWM frequency 490Hz, driving DIY 1kg robot.