The Simulation And Research Of Attitude Control System For Aerocraft

With the development of science and technology, the future high-tech war puts forward ever-increasing demands on indicators of aircraft. In order to improve the flight performance and range of the gliding extended aircraft with particular model, the simulation analysis and research of spacecraft attitude control system characteristics and the releated parameters of the control system have been done.which based on the control principle of the aircraft.In order to establish the control system model of the extended range glider aircraft, analyz-ed the structural characteristics of the control system which consists of three closed-loop.This paper is aiming at the type of this gliding extended range aircraft. The simulation and analysis of aircraft aerodynamic parameters such as lift,drag coefficient and moment coefficient have been done through Fluent software; defined the coordinate system and described the transform relations between the coordinate system; analyzed the external force and torque; established the space movement equations of gliding extendedrange aircraft.The disturbed motion equations are obtained by linearizing and simplifying the ballistic equations by the method of small disturbance. Under some assumptions, the disturbance of the gliding extended range aircraft can be divided into vertical disturbed movement and lateral disturbed motion. The transfer functions of two channels are induced by the coefficient freezing method. Take vertical disturbed motion for example, the stability of the gliding extended range aircraft are analyzed and studyed. According to the actual control requirements of the aircraft, an appropriate model of the actuator is established and the parameters of the actuator are adjusted. Finally, the close loop of the actuator system is brought into the longitudinal control system. PD controlling strategy is adopted in the pitch angle close loop,while PID controlling strategy is adopted in the height close loop.both of which are based on the control rule of the control system. Simulink Response Optimization Block of Matlab is used to choose the coefficient of the controller. Step response of each loop has been analyzed from perspective of time domain. Analysis of the amplitude and phase angle stability margin have been done from the perspective of frequency domain.The simulation results have shown that the design of the actuator system and longitudinal control system satisfy the targets of time domain and frequency domain,so that both of them are applicable for the flighting control of gliding extended range aircraft.