Research Of Control System Of Autopilot For Unmanned Aerial Vehicle

The birth and development of unmanned aerial vehicle technology is a great advance inthe world. Because of the special performance and application area, more and more countriespay attention to it, and invest enormous human, funds, and resources on it. Through tirelessresearches, the UAV capabilities are promoted continuously, and step into miniaturization,intellectualization, strong aggressivity and stealth. The unmanned aerial vehicle plays a majorrole not only in the military application, but also in the civilian use. This paper focus on theautopilot control system research with unmanned aerial vehicle as background.Autopilot is the core of unmanned aerial vehicle, which controls the plane’s movementautomatically according to the technical requirement and assignment. The main function is tomaintain the aircraft attitude and support the pilot. For UAV, the autopilot cooperates withother navigation equipments to complete flight mission. Mostly, the flight functions are doneby the UAV control system which includes processor, sensitive elements and actuators. In aword, a perfect automatic control system determines the performance of an aircraft. Thisresearch mainly focuses on the autopilot hardware design and control algorithm. The autopilotis designed base on the high-performance, low power consumption ARM processor, kinds ofMEMS sensors and modern control theory.This paper mainly focuses on two parts, hardware platform design and flight control law,then the attitude signal filtering and signal processing are also expounded. The main contentincludes: firstly, the state of development of autopilot about domestic and overseas unmannedaerial vehicles in recent years is analyzed. The advanced control method is discussed. Byconsidering autopilot technology characteristic and superiority, a design proposal is confirmed.Secondly, the component and structure of autopilot hardware is introduced. The processor,gyroscope, triaxial accelerometer, GPS and barometric altimeter’s characteristic and circuitdesign are analyzed. The hardware platform is designed according to the design target andUAV function. Thirdly, the appropriate space coordinate system is selected based on the UAVforce and torque, state-space equations are built from the vertical and lateral, and taken thelinearization process by small perturbation theory. Fourth, the building of vertical and laterallinear state-space equations is to check the equations’ stability according to the actualparameter, and the paper designs PID controller from pitch control channel, altitude controlchannel, roll control channel and yaw control channel in order to observe system timecorresponding curve, the controller function and the correctness of control strategy are analyzed. Fifth, from the practical application view, sensor output signal process is completedby Kalman filtering principle, which helps us get rid of high frequency noise signal andreduce error. Then the paper takes attitude algorithm to the filtered signal by four elementmethod, and deserves the angle signal. The aircraft coordination of control processes andcontrol methods are described detailedly finally.