Backstepping Control for a Class of Nonlinear Discrete-Time Systems Subject to Multisource Disturbances and Actuator Saturation

• Published in: IEEE transactions on cybernetics Vol. 52; no. 10; pp. 10924 - 10936
• Main Authors: Yu, Yang, Yuan, Yuan, Liu, Huaping
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.10.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Backstepping; Backstepping technique; Discrete time systems; disturbance observer; Disturbance observers; Disturbances; Harmonic analysis; hybrid observer; Linear matrix inequalities; linear matrix inequality (LMI); Mathematical analysis; multisource disturbances; Neural networks; Nonlinear systems; Nonlinearity; Process control; Radial basis function; Saturation
• ISSN: 2168-2267; 2168-2275; 2168-2275
• DOI: 10.1109/TCYB.2021.3071298

In this article, the backstepping control scheme is designed for a class of systems with multisource disturbances, actuator saturation, and nonlinearities in the domain of discrete time. To address the multisource disturbances, we put forward a novel discrete-time hybrid observer, which can deal with both modeled and unmodeled disturbances. In virtue of the radial basis function neural networks, the unknown nonlinearities are approximated. In addition, the anti-windup technique is adopted to cope with the actuator saturation phenomenon, which is pervasive in engineering practice. Bearing all the adopted mechanisms in mind, the composite control strategy is designed in a backstepping manner. Sufficient conditions are established to guarantee that the states of the system ultimately converge to a small range with linear matrix inequalities. Finally, the effectiveness of the presented methodology is verified for the spacecraft attitude system.