The Design Of Composite Navigation System For Multi-rotor UAV

The Composite navigation system of Multi-rotor UAV is responsible for real-time feedback of UAV attitude,speed,position and other flight state information.It is the foundation and core of UAV autonomous flight.The integrated navigation system of multi-rotor UAV is studied in this thesis.The hardware design,navigation algorithm and software design of the system are mainly studied.Hardware system design: Design the attitude heading subsystem and navigation subsystem based on modularization.Among them,the attitude heading subsystem design mainly includes six-axis sensor module,barometer module;navigation subsystem design includes power module,processor module,GNSS module,magnetometer module,CAN-BUS communication module.Aiming at some common problems such as geomagnetic interference,temperature drift of barometer and unstable GNSS signal,the corresponding improvement scheme is put forward.Navigation algorithm design: UAV attitude finding algorithm and GNSS/INS navigation algorithm are studied.Based on the data of gyroscope,accelerometer and magnetometer,the attitude information of the carrier is provided by the extended Kalman theory.The navigation algorithm takes GNSS positioning as the core information,and combines with inertial sensor data to calculate the smooth and accurate speed and position information.Software system design: Considering the requirements of the system task,the whole process of the software system is designed.The software flow design of CAN communication,sensor reading and firmware upgrade is designed in detail.In order to improve the performance of navigation system,the navigation algorithms are improved.Firstly,chooses an appropriate weight of Kalman filter and set it to a fixed value,thereby reducing the computation.Considering the instability of geomagnetic data and the vulnerability to external disturbance,the attitude compensation is carried out by using the velocity information of GNSS module in flight to improve the accuracy of attitude angle information.In addition,in order to compensate for the instability and delay of single GNSS,the GNSS data and INS data are fused to obtain more accurate and stable navigation information.To verify the reliability and stability of the integrated navigation system,the reasonability of hardware design,the processing effect of sensor data,the performance of attitude algorithm and navigation algorithm are tested.The experimental results show that,the designed integrated navigation system can provide stable and accurate navigation information for UAV and meet the application requirements of autonomous flight of UAV.