Design Of Flight Control System Simulation Based On Multiple Model Method

Design of flight control system is an important part of the overall design of the aircraft, has a significant impact on flight performance and quality of the aircraft. In flight simulation, flight control system design also has an important significance, is a very important part of the flight simulation system and has a decisive effect on the flight simulation, it is also of practical significance to the research of actual aircraft control system. In this thesis, the flight data recorded by the B737-800 aircraft Quick Access Recorder(QAR) is used to design flight control system of cruise phase in flight simulation based on multi-model control method. The main work of this paper is as follows:First of all, the aerodynamic parameters of aircraft change with flight status, therefore, according to the dynamic pressure, the cruise segment of QAR data is divided into several regions, then the aerodynamic parameters of each region is identified; based on the aircraft’s aerodynamic differential equations, a nonlinear model of aircraft is designed to facilitate the design of control system.Secondly, in order to facilitate the design of control laws, a trim system is established, several trim points is evenly got in each region and small perturbation linear models are extracted from the nonlinear model at trim points, then a nominal linear model is selected in each region; structure of control laws is selected and improved genetic algorithm is used to optimize control parameters to improve control design accuracy.Finally, the control laws switching system is designed, in order to avoid sudden change of control parameters then cause instability of system,a soften part of the handover process is designed.Then the effectiveness of the control system is verified.The simulation results shows this design method of the flight control system can get good results in flight simulation, improve flight simulation’s performance, and in the design of the actual aircraft flight control system has important value as reference.