DESIGN OF A DIGITAL FLIGHT CONTROL SYSTEM USING PIM METHOD

摘要

In the PIM(plant-input mapping) method, which is a digital redesign method, first a plant-input transfer function is obtained for an original continuous-time control system. It is a transfer function from an external input to a plant input. Then, it is discretized as a matched pole-zero model, and a digital control system is designed so that its plant-input transfer function can agree with the discretized one. Thereby, it is known that the discrete-time plant input can approximate the continuous-time plant input. The method guarantees stability of the digital control system for large sampling periods. It has been established for single-input single-output systems. However, it is not yet for multi-input multi-output (MIMO) systems. This paper proposes a design method for MIMO systems, based on the coprime factorization approach. It has been applied to design of a decoupling flight control system and its effectiveness illustrated through computer simulation.