Research On AHRS And RTK GPS Data Fusion Algorithm For UAV And Implementation Of Hardware And Software

The rapid development of unmanned aerial vehicle(UAV)has made it widely used in various fields.At present,UAV has become a hot topic for research in express industry,aerial photography,agriculture,plant protection and disaster relief in information-based societies.The whole world is devoted to improving the stability of the UAV flight control system and the accuracy of the positioning system.Therefore,the design of the system is based on the flight control system and the RTK GPS positioning system,it is of great theoretical and practical value to study the fusion of AHRS and RTK GPS data to maximize the accuracy of flight control’s stability and location.This paperfirstly studies and implements the AHRS and RTK GPS data fusion algorithms.Explain the conversion relationship between quaternion,Euler angle and rotation matrix in AHRS and RTK GPS positioning principle.And analyze several common data fusion algorithms such as Least Squares Estimation,Wiener Filter(Linear Minimum Variance Estimation),Kalman Filter,and Extended Kalman Filter,and compare the formula derivation,algorithm complexity and error magnitude.Finally,it is confirmed that the data fusion algorithm of the system based on the extended Calman filter is used to optimize the system’s input dimension and external noise parameters to achieve the system output optimal state data,and the data fusion algorithm of AHRS and RTK GPS is simulated and analyzed by MATLAB.To verify the feasibility of the data fusion algorithm,this article has finished the system software and hardware design.The hardware circuit includes the flight control system hardware circuit and the RTK GPS positioning system hardware circuit.The flight control system needs to provide the basic data of the AHRS,and uses a high-performance STM32F4 series chip as the main controller chip to complete the data reception,transmission and processing.The required gyroscopes,accelerometers,magnetic induction,pressure,and other data are collected by external sensors.RTK GPS positioning system uses NEO-M8P positioning chip to provide high-precision positioning data for the system.The flight control software system mainly includes the establishment of the embedded Linux system development environment,the configuration and compilation of the Nuttx system,the compilation of the flight control system,and the programming of the firmware.At the same time,the ground station is constructed,which can transmit the flight instructions and communication data with the filight control system through the wireless transmission.The RTK GPS positioning software design mainly needs to configure the hardware circuit through u-center to achieve the strongest satellite signal.Finally,the paper tests the data fusion algorithm,software and hardware platform of the whole system.Simulation is performed by inputting actual flight data to the system data fusion algorithm and compared with the output data,the results show that the implementation of the fusion algorithm in the flight control system makes the output data closer to the actual value,increases the amount of data per unit times,and effectively reduces the impact of noise on the system.At the same time,by testing and analyzing the hardware and software platform,it is known that the system has the characteristics of low power consumption,fast processing data,short positioning time,high precision and high stability,and the system can get high precision positioning information in real time.