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

A new digital self-tuning tracking controller for the 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 and cogging allows for arbitrarily accurate identification of higher-order harmonics, without requiring more computation than traditional single-term sinusoidal descriptions. Experimental results demonstrate that good performance is achieved even with very poor initial parameter knowledge