Constrained Optimal Preview Control of Dual-Stage Actuators

This paper proposes constrained optimal trajectories for the preview control of dual-stage actuators (DSA). Relying on the redundancy of actuators preview control allows the primary stage to move before the transition instant, and uses the secondary stage to compensate its movements. Contrasting existing strategies that consider the secondary stage infinitely fast during preview control, this study takes into account its dynamic limitations when designing the trajectories to be followed during preactuation. It will be shown that the problem may be cast in terms of quadratic programming providing an optimal solution with respect to a quadratic criterion. Experimental results validated the proposed strategy, which is able to achieve a 30% improvement over state-of-the-art high-performance DSA controllers, while respecting the limitations of both actuators.