Multi-Input and Multi-Output Discrete Time Output Feedback Control System Design Method Based on Improved Optimal Regulator Theory

Abstract

Multi-input and multi-output output feedback control system design method based on improved optimal regulator theory is proposed. Steady state errors of the output feedback control system remain zero for changes in the desired signals and the disturbance signals and in spite of the parameter variations of the controlled object, same as in the full state feedback control system previously proposed by the author. The control system structure of the output feedback control system as well as the full state feedback control system are clarified. It is shown that proportional actions and integral actions are included in the full state feedback control system, on the other hand, derivative actions as well as proportional actions and integral actions are included in the output feedback control system. That is, (n-1)th and (n-2)th order derivative actions for error signals and disturbance signals are introduced for n-th order controlled object. In order to improve the transient responses for changes in the deisred signals and the disturbances, feedforward control loops utilizing the informations on the signals, if possible, are introduced for both the systems. Input delay times due to the processing time required to execute the employed control algorithm in a microprocessor are also easily taken into account in this design method, which results in the introduction of the compensating actions for the input delay times.