Adaptive Control Research Of Civil Aircraft In Special Flight Envelope Constraint

Loss of Control caused by flight emergency is one of the main inducements of civil aviation accidents.With the improvement of aircraft automation,preventing Loss of Control through control systems has become the focus of civil aviation safety research.In this paper,the method of model reference adaptive control and fuzzy control was adopted to improve the safety of the aircraft landing in the case of flight emergency.Based on the control of Loss of Control envelope protection,the multi-loop control law of the aircraft was designed,and the low-altitude wind shear was taken as an example to verify the control law.The main research contents are as follows:(1)The quantitative Loss of Control envelop of different civil aircraft was analyzed,and the changes of Loss of Control envelopes were studied separately under the three kinds of flight emergency: ice accretion,rudder jamming and disturbance wind,and a design method of multi-loop control law for flight Loss-of-Control envelope protection was studied.(2)An aircraft dynamics model with disturbing wind effects was established.Fuzzy dynamic inverse multi-loop control framework was built,and the internal and external loop control laws was designed.The lateral side simulation test was carried out to verify the correctness of the inner loop Loss of Control envelope protection law and outer loop task control law.(3)A linear variable parameter model was established,and a model reference adaptive control framework was built.Based on generalized predictive control with control constraints,the adaptive control law was designed.And longitudinal escape simulation test was performed to verify the effectiveness of Loss of Control envelope protection control law.(4)The low-altitude wind shear of the landing of the aircraft was taken as an example,the wind shear escape multi-loop flight control framework was built.Based on different flight conditions,a reasonable control strategy was selected,and the fuzzy dynamic inverse control lateral escape wind shear simulation test and model reference adaptive control longitudinal escape wind shear simulation test were performed to verify the effectiveness of the wind shear escape multi-loop control law.