Two-Degree-of-Freedom GMVC-Based PID Controller Using Pre-Compensator

This paper discusses the design methods of generalized mininum variance control (GMVC)-based PID controllers in a two-degree-of-freedom (2DOF) system. The PID parameters of PID controllers are designed based on GMVC, and the PID controllers are designed as self-tuning controllers. In design of a 2DOF PID controller based on GMVC with a feed-forward compensator (abbreviated as FF-type GMVC), because the order of a feed-forward compensator depends on a dead-time, the longer the dead-time is, the worse approximation error is. Therefore, in this paper, to obtain better approximation, GMVC with a pre- compensator (PC-type GMVC) is approximated by a 2DOF PID controller. Further, to improve control performance, a 2DOF PID controller having time-varying proportional gain is designed based on strongly stable GMVC with a pre-compensator.