A Stability Guaranteed Active Fault-Tolerant Control System

In this paper, we focus on the problem of active management of actuator redundancy for fault-tolerant control of linear systems in the presence of both parameter uncertainty and actuator failures. In the proposed method, multiple controllers are designed based on the concept of quadratic stablizing control, in which each controller is determined under the assumption that one specified actuator, named the main actuator, is failure-free. During the course of system operation, the best controller is selected automatically based on the result of fault detection and isolation process. The significance of the proposed active fault-tolerant control system is that the stability of the closed-loop system is always guaranteed even in the presence of fault isolation errors. Such errors only affect control performance. Therefore, the scheme provides a good trade-off among the conflicting requirements on stability and performance. This control starategy has been demonstrated on a lateral-directional dynamics of a McDonnel F-4C airplane by simulation.