PIM digital redesign method and its application to the design of a digital flight controller

In the digital redesign approach considering the closed-loop characteristics of the underlying continuous-time (CT) control system, the plant input mapping (PIM) method has previously been proposed based on the plant input transfer function (PITF) discretized by the matched pole-zero model. The authors have subsequently proposed the modified algorithm of this method using the standard H/spl infin/ problem for redesigning into an one-degree-of-freedom (1-DOF) digital control system, and the discretization method of the PITF utilizing the inter-sample responses of the step invariance model for redesigning the multi-input multi-output (MIMO) CT control system. This paper presents its extension to the redesign for the two-degree-of-freedom (2-DOF) CT control system. The simulation studies are performed for the redesign of a digital CCV flight control system to illustrate the effectiveness of the proposed method.