Disturbance‐prediction–based control of input time delay systems for rejection of unknown frequency disturbances

• Published in: International journal of robust and nonlinear control Vol. 30; no. 1; pp. 338 - 350
• Main Authors: Wen, Xinyu, Yan, Peng
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 10.01.2020
• Subjects: Control systems; disturbance prediction; Disturbances; disturbance‐observer–based control; Predictions; Rejection; time delay; Time delay systems
• ISSN: 1049-8923; 1099-1239
• DOI: 10.1002/rnc.4770

Summary In this paper, a novel disturbance rejection approach is presented for a class of input time‐delay systems subject to sinusoidal disturbances with unknown frequency. In particular, an auxiliary observer is proposed to represent the periodic disturbance in a parametric uncertainty form, where the unknown factor related to disturbance frequency can be estimated. Furthermore, the correlation between the future disturbance and the auxiliary observer output is analyzed, such that the future disturbances can be predicted and rejected through the input channel. Based on the aforementioned observer and predictor structure, the overall control architecture can be established as a framework of disturbance‐prediction–based control for systems with input time delays, where the conditions on the asymptotic stability of the closed‐loop systems are also derived. Finally, numerical examples are provided to illustrate the effectiveness of the proposed control approach.