Research On Control Technology Of A Six-Rotor Unmanned Helicopter

This dissertation describes the research on flight control technology of a novel six-rotor unmanned helicopter, especially the dynamic modeling of helicopter and the design of its flight control law. PID method, LQ control and Dynamic Inversion theory are employed. It is verified by the simulation that the flight control system obtained can make the six-rotor unmanned helicopter fly autonomously between targets, keep stable and reach the desired goal even under some input disturbances or changes of model parameters.At first, the dynamic characteristics of the six-rotor unmanned helicopter are analyzed, getting the dynamic equations of rotation and the dynamic equations of translation. Also, the mathematical model is simplified.PI control and LQ control are respectively used to design the attitude control system of the unmanned helicopter which ensures the adequate stability margins of the control systems obtained. The process of attitude control is simulated in order to test the performance of the control system, especially the robustness when there is disturbance. Besides, the simulation results between the PI control and the LQ control are compared.What’s more, a combine method of PID control and Dynamic Inversion theory is employed to design the altitude control system of the unmanned helicopter. And robust PD control is used to design its planimetric position control system. As a result, the stability margins of the flight position (altitude and planimetric position) control system obtained is adequate. Through the simulation of the Flight-position Control process in different conditions, the performance of control system is tested and analyzed.Finally, a three-dimensional simulation of the six-rotor unmanned helicopter’s flight trajectory is carried out and its results verify the validity of the Flight Control system design.