Optimal Preview Control of Dual-Stage Actuators System for Triangular Reference Tracking

This paper proposes an optimal preview control law for a dual-stage actuators (DSA) system to track triangular references, which is essential in many raster scan motion control applications. The main difficulty of tracking triangular reference is to follow the waveform fast and accurately when its slope switches. For this goal, we first present a non-preview time optimal control for the primary stage, which is proved to have the minimal overshoot. This result is a new contribution to DSA control because it leads to a minimal reference profile for secondary stage to follow and thus significantly prevents the saturation of the secondary actuator. Next, we propose an optimal preview control with the use of the information of the future references to further reduce the settling time and the overshoot. Finally, the secondary actuator controller is also given. Simulated results are shown to verify the effectiveness of the proposed control design.