ACTUATOR SATURATION COMPENSATION FOR SELF-TUNING CONTROLLERS

In linear control system design, it is often assumed that control is u nbounded. However, due to practical constraints, actuator saturation o ften occurs. To compensate for the actuator saturation, heuristic tech niques are developed and can be found in the literature. In this paper , the optimal compensation for a class of sub-optimal control laws suc h as the minimum variance, generalized minimum variance, k-incremental , integrating and generalized predictive control is derived. Compariso ns with non-optimal schemes such as those derived heuristically are ma de. It is shown that the optimal compensation scheme also yields the l owest accumulated sum of the cost function under certain conditions, a lthough the result does not generally hold, as illustrated by a numeri cal example.