Adaptive two degrees-of-freedom internal model control with reference input predictor for systems with unknown time delay

Authors:	Ren X. M., Beijing Institute of Technology, China Rad A. B., The Hong Kong Polytechnic University, Hong Kong Lo W. L., The Hong Kong Polytechnic University, Hong Kong Chan P. T., The Hong Kong Polytechnic University, Hong Kong
Topic:	1.2 Adaptive and Learning Systems
Session:	Adaptive and Learning Approaches to Controller Design
Keywords:	Time delay systems; Identification; Least-squares algorithm; Internal model control

Abstract

A new adaptive two degrees-of-freedom internal model control (IMC) with reference input predictor is presented for continuous-time systems with unknown time delay. The proposed controller consists of reference input predictor, model reference controller, disturbance rejection controller and internal model predictor. The reference input predictor is used to compensate for time delay transfer function from the time-varying reference input to the output of the actual plant. The model reference controller is employed to make the plant output track the output of the stable reference model. The disturbance rejection controller is used to optimize the disturbance response. The unknown time-delay and rational transfer function of continuous-time systems are simultaneously estimated by making use of the modified normalized least-squares algorithm with projection. One feature of the proposed alg