Fault-Tolerant Control for Flexible Structures With Partial Output Constraint

In this article, we propose an adaptive fault-tolerant control strategy for flexible string systems and extend the result to Euler-Bernoulli beam systems under deferred and asymmetric boundary partial output constraints. The designed control strategies consist of a boundary control law and two adaptive parameter update laws. A hyperbolic tangent function is applied to realize rejection to disturbance. With the adaptive technique, the unknown actuator faults are compensated. The deferred partial output constraints are addressed by utilizing a shifting function to remove the initial limitation on the boundary output and constructing a novel asymmetric barrier Lyapunov function. Furthermore, it is proven that both the controlled string and Euler-Bernoulli beam systems are well-posed and meet the deferred constraint conditions. Finally, extensive simulation examples are presented to demonstrate the performance of the proposed control methods.