Adaptive Tracking Control of Nonstrict-Feedback Nonlinear Systems with Actuator Faults and Input Delay via a Fuzzy Funnel Approach

This article investigates an adaptive fuzzy funnel control approach for nonstrict-feedback nonlinear systems with actuator faults and input delay. Fuzzy logic systems (FLSs) are utilized to estimate unknown functions, while the Pade approximation technique is applied to address the effects of input delay. By leveraging the approximation capabilities of FLSs and the backstepping control technique, an adaptive funnel control scheme is developed. This scheme ensures that all closed-loop signals are semi-globally uniformly ultimately bounded (SGUUB). Utilizing funnel control, the tracking error is kept within a predefined funnel and converges to a specified interval using a funnel function. The effectiveness of the proposed controller is validated with a real-world example involving an electromechanical system.