Event-Triggered Adaptive Fault-Tolerant Boundary Control for Flexible Bionic Fish Tail With Output Constraint

Abstract

The article focuses on the tracking issue of a flexible bionic fish tail system under boundary control. The flexible bionic fish tail system is modeled as an Euler-Bernoulli beam with non-uniform parameters, where its actuator is a DC motor located at the front end of the tail. Firstly, the problem of partial actuator failure was resolved using an adaptive compensation approach. Secondly, a barrier Lyapunov function is designed to ensure that the tracking error does not exceed a predetermined range. Moreover, an event-triggered control (ETC) strategy was put forward using a fixed threshold policy, facilitating periodic vibrations of the flexible fish tail by tracking the reference signal and diminishing the communication burden between the controller and the actuator. Finally, the closed-loop system was proven to be uniformly ultimately bounded using the direct Lyapunov method, with the tracking error approaching a neighborhood of zero. The efficacy of the proposed control law was confirmed through numerical simulation results.