Control System Reconfiguration Technology In The High Viability Of The Flight Control System Design

The High-altitude, long-endurance (HALE) Unmanned Aerial Vehicles (UAV) is used to carry out high reconnaissance or to head off missiles. Since HALE UAV has a feature of high altitude and long endurance, the probability of control surface failures is increased highly. When it does happen, the failure would most likely result in fatal accidents. This dissertation investigates design of reconfigurable flight control systems of a certain model HALE UAV which is supported by Initiative Research Project Fund of China during the 10th 5 Year Plan.Reconfigurable flight control systems are control systems that are characterized by the ability to perform in the presence of drastic changes in the system dynamics due, for example, to abrupt system component failures or rapid changes in the operating conditions.Based on the flight datum of A300, the mathematical models and the normal control law of UAV are built. Separating the traditional flight control surfaces into several independent portions, we can reduce the influence of the control surface each and add redundance to the systems at the meanwhile. According to the fault type of the flight control surfaces, they are classified and modeled. Further, the reconfigurable control law is designed undergoing the elevator and aileron failures.An Optimization Algorithm for the problem of control reconfiguration in response to operating condition changes or abrupt system component failures is presented here. The algorithm provides an output feedback controller that not only stabilizes the impaired system, when possible, but also preserves much of the dynamics of the unfailed system. The design is such that the closed-loop system is robust with respect to inevitable uncertainties/modeling errors on the state-space matrices of the impaired system.The Model Following Method can make the outputs of failure system exactingly tracking those of reference model by detecting the location and amplitude of failure of actuator failure, modifying control parameter, and redesigning control law on-line to counteract dynamics caused by actuators failure. The approach maintains the simplicity of the original algorithm, and carry out perfect model following. The Pseudo-Inverse Method is concerned with distributing the deflection commands of multiple control surfaces of the aircraft to generate required control responses when the number of independent control surfaces is greater than the number of required independent control responses.All of the examples presented in this dissertation demonstrate the efficiency of the reconfigurable control approaches.