Abstract
PID controllers have been widely used in many industrial processes. Because they have only three control parameters, and we can easily understand their physical meanings. However, it is difficult to tune their parameters in the case where the control system has uncertainties, for example, modelling errors, system fluctuation, and so on. Therefore, we propose a design scheme of discrete robust PID controllers in this paper. That is, we design a PID controller based on the generalized minimum variance control (GMVC) scheme, and present a method how to design a weighting factor included in the GMVC criterion from the viewpoint of the robust stability. Furthermore, we investigate the behavior of the proposed control scheme by applying it to an air pressure control system.
