Fault Tolerant Flight Control Law Design Of Tilt-Rotor

Tilt rotor aircraft fault tolerant flight control law design is one of the key technologies due to its multi flight modes(helicopter, airplane and conversion mode), complex control and redundant control servo surface. Redundant servo surface provides basis of control law reconfiguration.This paper aims unmanned tilt rotor as the research object, the nonlinear aircraft flight dynamics model is established to obtain handling quality in helicopter mode, tilting transition mode and airplane mode, analyze control surface operating efficiency, and determine control servo surface allocation strategy in different flight mode and reasonable conversion path.According to the reasonable transition path, tilt rotor aircraft full mode control law is designed by using dynamic inverse combined with PID control. For tilt rotor aircraft control servo surface redundant features, the multi-model fault tolerant flight control system and direct adaptive fault-tolerant flight control system are presented to achieve a good tracking command with control surface failure in flight.Finally,the multiple-layer hybrid adaptive control law is presented by integrating direct theory and multiple model adaptive theory, which effectively overcome foreseeable and unforeseeable control servo surface failure. Direct adaptive control focus on surface damage, and multiple model adaptive control aims at control surface floating. Based on this measure, adaptive control law has good tracking performance under control surface failure. The simulation results show that the present method is feasible in tilt rotor control law design.