A digital self-tuning tracking controller for permanent-magnet synchronous motors

A new digital self-tuning tracking controller for a permanent-magnet synchronous motor is presented, providing for either velocity or position trajectory tracking when both the electrical and mechanical parameters of the motor are unknown. A time-scale simplification leads to a discrete-time design model that is reduced-order and that evolves in the slower mechanical time-scale. A new piecewise-linear parameterization of the motor torque-angle characteristic functions allows for arbitrarily accurate identification of higher-order harmonics, without requiring more computation than traditional single-term sinusoidal descriptions. Experimental results demonstrate that excellent performance is achieved, even with very poor initial parameter knowledge