Navigation And Control System Design For Multi-rotor UAV

Multi-rotor UAV has been widely used in agriculture,plant protection,power inspection,aerial photography and other industries.However,how to improve the safety and stability of UAV in complex environment is still a serious problem.Based on the existing hardware platform of UAV,the navigation algorithm and flight control algorithm are studied to realize autonomous point flight in this thesis.The main research contents are as follows.The existing Quad-Rotor airframe and STM32 embedded hardware are selected to provide experimental test platform for navigation and flight control algorithm research.The research of navigation algorithm includes attitude calculation and integrated navigation.Based on gyroscope,accelerometer and magnetic compass data,the attitude information of the airframe is calculated by extended Kalman theory.The algorithm selects a stationary value as the Kalman filter weight,so that the computational complexity is reduced.In addition,the heading angle is compensated by satellite positioning data to improve the accuracy of attitude angle information.The data fusion of integrated navigation algorithm based on the satellite positioning information,combines inertial data to compensate for the instability and delay of satellite positioning information,and the smooth and stable speed and position information is obtained.To design the flight control system,the six-degree-of-freedom motion of multi-rotor UAV in space is analyzed,and the mathematical models of attitude,velocity and altitude are established.The system identification tool is used to identify the specific parameters of the model.According to the structure of the control system,the design of autonomous flight control system is divided into four independent control loops: horizontal lateral control,horizontal longitudinal control,altitude control and heading control.Considering the characteristics of model disturbance and susceptibility to load variation,the model reference sliding mode control theory is adopted to improve the robustness.The outdoor experiment results show that,the calculated attitude angle,velocity and position data of the designed navigation system coincides well with the high-precision reference equipment,and can provide stable and accurate navigation information for UAV.The designed control system has completed the autonomous waypoint flight of the experimental machine,and has good anti-interference and robust performance,which verifies the effectiveness of the navigation algorithm and control system design.