Autonomous Control System For The Quadrotor Unmanned Aerial Vehicle

Unmanned aerial vehicle (UA V) is a speci al kind of aircraft, which can be manipulated by the radio remote control equipment and self-control devices. UAV can be divided into two main categories: fixed-wing UAV and rotorcraft UA V. The technology of the fixed-wing UA V has been matured, in contrast, the research of rotorcraft UAV is still o n its p ath. However, rotorcraft UAV has m any irreplaceable advantages, such as the capability o f vertical takeoff and landing, agile flight ability (hovering, backwards flying, side-flying, etc. ), stronger environm ental adaptability, and so on. As a common kind of rotorcraft UAV, the quadrotor has attracted more and more attention, and becomes a hotspot of the research both domestic and abroad. This thesis designs an autonomous flight control system for the quadrotor helicopter. Autonom ous control of the ro ll angle, pitch angle and the horizontal direction altogether four degrees of free dom in hovering state has been obtained. The main contents of this thesis are listed as follows:(1) The hardware configuration of the autonomous control system has been designed. In full consideration of quadr otor’s dynam ic properties and payload capacity, suitable body fra me of t he aircraft , controllers, and sensors have been determined. On the basis of rem ote control system, we completed the conversion of the control signals. S erial communication between th e airbo rne e quipments is completed.(2) The dynam ic m odel of quadrotor has the cha racteristics of no nlinearity, under-actuated, and strong coupling. This th esis used an inner -outer-loop control scheme. The nonlinear system is decomposed into two linear subsystems. And the two cascaded subsystems coupled by a nonlinea r interconnection te rm. The inner loop performs the attitude tracking, and the outer loop performs the trajectory tracking. The PD control algorithms are employed for both inner loop control and outer loop control. And at last, we write C++ program for the implementation of the control algorithms.(3) The th esis introdu ced the basic p rocess of the control procedure. W e completed the num erical s imulation vi a MA TLAB/SIMULINK, and verified the theoretical feasibility of the control law. Then, we did the hovering flight test, and the results showed that the hovering flight controller is stable.The difficulty of this paper is a combin ation of the control algorithm and actual hardware system.