Bounded control of feedforward nonlinear systems subject to input time‐delay

• Published in: International journal of robust and nonlinear control Vol. 30; no. 14; pp. 5579 - 5601
• Main Authors: Yang, Xuefei, Zhou, Bin, Lam, James, Cao, Yong
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 25.09.2020
• Subjects: bounded control; Control systems design; Controllers; Decoupling; Feedback control; Feedforward control; feedforward nonlinear systems; global stabilization; Integrators; Linearization; Nonlinear control; nonlinear feedback; Nonlinear systems; Oscillators; Recursive methods; Stabilization; Time delay systems; time‐delay
• DOI: 10.1002/rnc.5098
• ISSN: 1049-8923

Summary This article is concerned with the global stabilization problem of a family of feedforward nonlinear time‐delay systems whose linearized system consists of multiple distinct oscillators. To fully utilize the delayed information and maintain the state decoupling property in the controller design, the considered nonlinear feedforward system is first transformed into a new system which contains time delays in both its input and states based on a novel model transformation containing time delays, and then the stabilizing saturated controller for the transformed system is designed based on the recursive design method. Meanwhile, explicit stability conditions are also provided. When the linearized system is a cascade of multiple oscillators and multiple integrators, a modified saturated feedback control utilizing not only the current state but also the delayed state is also established for the corresponding global stabilization problem. Two examples, including a practical one, are given to show the effectiveness and superiority of the proposed approaches.