Strongly Stable Generalized Predictive Control Focused on Closed-loop Characteristics

Abstract

This paper proposes a design method of strongly stable generalized predictive control (GPC) focused on closed-loop characteristics. GPC can be extended by coprime factorization, and the extended controller can be designed to be stable by selecting newly introduced parameter. That is, strongly stable system, which means both the closed-loop system and its controller are stable, can be obtained. Although the authors have considered the design method of strongly stable system using coprime factorization, the steady state of output has not been considered when feedback loop was cut. In the case that the controlled plant is stable, the steady state output of strongly stable system is stable even if feedback loop is cut. But for safety, it is desirable that the steady state of output becomes as close to the steady state of closed-loop output as possible even if feedback loop was cut. Therefore this paper explores a design method of strongly stable GPC focused on closed-loop characteristics by algebraic calculation of newly introduced parameter in the extended GPC. The proposed method has the feature that the steady state of output becomes the same as the steady state of closed-loop output even if feedback loop is cut.