H∞ control of permanent magnet linear synchronous motor based on internal model theory

This paper presents a H_∞ speed controller based on internal model theory. The output point mixed sensitivity method is adopted to restrain the disturbance of servo system and guarantee the robust stability. A proximate internal model is introduced into disturbance path when solving the standard H_∞ control problem. It can simplify the design and satisfy the requirement of servo performance. A H_∞ load disturbance observer is designed which achieves the disturbance cancellation and guarantees robust stability. Simulation results show that the system has improved performance by the methods proposed in this paper.