Fault-Tolerant Robust Automatic Landing Control Design

A new approach is presented for developing reliable automatic landing controllers that can tolerate actuator stuck faults. The approach is based on the solvability of linear matrix inequalities and polytopic fault models. The H 2 control technique is used to guarantee tracking performance with respect to a given glide slope trajectory. A high-fidelity fighter aircraft model is studied to illustrate the proposed approach. The six-degree-of-freedom nonlinear aircraft model with independent left and right control surfaces is established using the appropriate aerodynamic data from wind-tunnel test and computational fluid dynamics. A single fixed reliable automatic landing controller is designed for the whole landing process. It achieves optimized tracking performance in normal operation and maintains an acceptable level of tracking performance in the case of single contingency actuator stuck fault among the left and right ailerons and horizontal stabilators. Nonlinear simulation under various faults, measurement noises, and wind disturbances such as deterministic wind, wind turbulence, and wind shear are included in this study. Simulation results show that such a reliable controller design approach can achieve zero steady-state tracking error, good tracking response, robustness against wind disturbances, and reliability against actuator stuck faults.