Robust Variable Structure Controller Design for Fault Tolerant Flight Control

In this paper, a variable structure control (VSC) based model following control system that possesses fault detection and isolation(FDI) capability as well as fault tolerance property is proposed. With the scheme, parameter estimation process for reconfigurable control is not necessary. The main idea of the proposed algorithm stems from the fact that nonlinear control of VSC counteracts to external disturbances. The proposed algorithm is shown to be very useful for the case of control effector damage in aircraft, where the parameter change and external fault signal satisfy the matching conditions. With the comparison of nonlinear control suppressing fault effect and adequate outputs, it is also possible to determine how serious the damage is. The numerical result shows the applicability of the proposed algorithm in this paper.