Design Of Four-Rotor Aircraft Control System

In this paper, a new type of helicopter, Four-Rotor aircraft, has been designed and introduced. Four-rotor aircraft is a kind of Micro Unmanned Aerial Vehicle, compared with traditional unmanned aerial vehicle, the strong maneuverability and high bearing capability make it easy to achieve vertical take-off and landing under ideal stationary or quasi-stationary fight conditions, and provide the aircraft with a broad developing prospect in both military and civilian areas.The objective of the research is achieving the stable vertical take-off and landing of the aircraft and flying attitude adjustment in a small angle range. The present developing status of four-rotor aircraft at home and abroad and the main content of the research have firstly been introduced in the paper, then based on the investigation of four-rotor aircraft's flight principle, an integral structure of the aircraft system has been designed by using a structure-modularizing method as designing concept and AduC7026 as the microcontroller, and the hardware circuit of the main control module, driving module, testing module and executive module have been accomplished with it. Combined with the hardware structure, the software programming of the system has also been fulfilled using C programming language.As an under-actuated multi-input and multi-output system, four-rotor aircraft has some unexpected dynamic features such as high coupling degree, non linearity and time-varying, this makes the controlling of the aircraft very complicated. To solve this problem, a loop shaping method based on H_∞control theory has been presented to realize the designing of system controller, the method combines classic loop shaping and the concept of bandwidth with the robust stability of modern H_∞control theory, and gives full consideration of the effect of system's uncertainty to ensure robust stability of the system and optimizes the performance index. The dynamic module of the aircraft has been built for controller simulation, after simulating using Matlab, the control performance of the designed controller has been vertified.In the end, the performance of system modules has been tested, and the aircraft designed has completed its flying experiment under current laboratory codition successfully, which vertified the rationality of the designation.