FUTURE REFERENCE TRAJECTORY IMPROVEMENT IN SELF-TUNING I-PD CONTROLLER BASED ON GENERALIZED PREDICTIVE CONTROL LAW

Abstract

In this paper a new design method of a self-tuning I-PD controller is proposed. The I-PD controller is designed based on a generalized predictive control (GPC) law. By using a conventional design method of the I-PD controller based on the GPC law, it is impossible to introduce future reference trajectory into the I-PD controller. The future reference trajectory of the GPC approaches a set-point value gradually from a present output, that is one of the features of the GPC. The proposed method can introduce the advantage of the GPC into the I-PD controller exactly because the proposed method expresses the future reference trajectory suitably when the set-point value is given as a step type signal. This paper shows that the structure of a PID controller based on the GPC law becomes an I-PD type by using the proposed method and that a design parameter of the GPC which adjusts the future reference trajectory influences only an integral time of the I-PD controller.In order to illustrate the effectiveness of the newly proposed method, numerical examples are shown.