Adaptive Prescribed Time Fuzzy Control of Interconnected Nonlinear Systems and Its Applications: A Compensation-Based Approach

This paper investigates the trajectory tracking control problem of the interconnected nonlinear system subjected to dead zone inputs. A compensation-based prescribed-time fuzzy control framework is designed and successfully implemented on an interconnected system’s real experimental device. A prescribed-time convergence performance boundary function and a tan-type transformation function are introduced to constrain the tracking errors of each subsystem within the interconnected system. To cope with the dynamic changes in the design process caused by error transformations and the effects of disturbances, an adaptive compensation strategy for offset compensation is developed. The unknown system interconnection dynamics are treated as uncertain dynamics, and an adaptive fuzzy logic estimation strategy is designed to offset the effects of the unknown interconnection dynamics and system nonlinear dynamics. In addition, a parameter estimation law is proposed to reduce the effect of dead zone inputs on the control system. The control input event triggering mechanism is developed to reduce the update frequency of the control signals. The stability analysis of the proposed control framework proves that all signals are ultimately bounded. Compared with traditional control strategies for interconnected systems, the designed control framework does not require assumptions about the interconnection dynamics of the system, and the proposed compensation strategy enhances the robustness of the control system. Crucially, this research work verifies the effectiveness and superiority of the designed control framework in practical applications. Note to Practitioners—With the development of modern technology, practical engineering systems have become more and more large, and these large systems contain many subsystems with interconnected influences, so it is necessary to further study the control problems of interconnected nonlinear systems in depth. In the application of real interconnected systems, the existence of interconnection dynamics is the main reason to affect the control effect, so it is a hot issue to study how to eliminate and reduce the interconnection effect and realize fast tracking. In addition, most of the interconnected systems in real engineering applications have dead zone control problems, so it is necessary to design a compensation control strategy to improve control accuracy. In this paper, we discuss the adaptive prescribed-time fuzzy control problem for interconnected nonlinear systems, design a fuzzy compensating control mechanism, and develop a prescribed-time tracking controller to realize fast-tracking of the system and improve tracking accuracy.