Adaptive fault-tolerant control and online control allocation for strict-feedback nonlinear systems with actuator faults.

In systems with multiple redundant actuators, the existing direct adaptive fault-tolerant control (FTC) methods adopt a static control allocation strategy, which in turn leads to an imbalance in the utilization of control resources. In this paper, an adaptive FTC scheme with an online control allocation algorithm is proposed for a class of nonlinear systems. The algorithm dynamically adjusts the control allocation among actuators based on their estimated efficiency coefficients, thereby prioritizing control effort to healthier actuators. Furthermore, to balance performance with computational efficiency, the algorithm adaptively modulates the update frequency of the control weights according to the rate of fault variation. Experimental results demonstrate the effectiveness of the proposed scheme.