Kang Zhi Liu

Design of optimal strongly stable digital control systems and application to output feedback control of mechanical systems

ABSTRACT A new design method for an optimal digital series compensator is considered that is not produced by an optimal regulator incorporated with a state observer, but employs a new idea that assures total closed system optimality in one design step. However, the compensator so designed is not always stable, i.e. strong stability of the closed-loop system is not always guaranteed. For this case, the authors propose to use the inter-sample response to realize an optimal stable compensator and/or optimal output feedback control system. Especially when the given plant is a linearized mechanical system, such a strongly stable system can always be designed using only output data two samples prior to the current sample regardless of the system order and the parity interlacing property condition.

Design of an optimal series compensator based on DARMA model—The MIMO case

Abstract Design of an optimal series compensator for MIMO systems is considered in this paper using the DARMA form. The main purpose is to show how to find the smallest number of samples in each output channel to yield an optimal series compensator which is of the smallest possible order.