Design And Implementation Of High Precision Attitude Measuring System

With the continuous development of the military technology and the industrial technology,people's requirement for navigation accuracy is higher and higher,and for the accuracy of attitude measurement is higher and higher,so the development of high-precision attitude measurement technology is getting more and more attention.The paper,aiming at the high precision demand of the attitude measurement system,based on the basic theory of attitude measurement,puts forward a low cost attitude measurement system design scheme with high precision,and in this design scheme,the accelerometer,gyroscope and gps are used together to calculate the exact position matrix and the position rate by using the accurate position velocity value of gps output.Then the quaternion and attitude matrix are calculated with the output of the gyroscope,and the attitude angle is obtained.When GPS fails,the attitude is calculated by the output of accelerometer and gyroscope.The position and velocity information of the high precision GPS output is used as the input of the external measurement value,and the extended Kalman filter algorithm is used to estimate the error.The attitude measurement system includes the data acquisition subsystem and the navigation solution subsystem.The data acquisition subsystem mainly includes the FPGA core controller,the inertial measurement unit(IMU)and the GPS receiving unit.The inertial measurement unit outputs the accelerometer and gyroscope data.The GPS receiver unit outputs the position and velocity data,and the FPGA simulates SPI serial port and UART serial port to realize the multi-channel data acquisition of IMU and GPS simultaneously.The navigation solution subsystem regards DSP as the core controller,and is responsible for the data fusion using Kalman filter algorithm to obtain high-precision attitude information.In this paper,a pure strapdown attitude algorithm and a high precision attitude algorithm based on extended Kalman filter are designed.Based on the theory of Kalman filtering algorithm,the state equation and measurement equation of attitude measurement system are derived.The attitude angle error calculated by the attitude calculation algorithm is simulated and analyzed,and the feasibility of high precision attitude measurement of the attitude measurement system is verified.Finally,the attitude information obtained by the system navigation is sent to the display interface of the upper computer through the UART serial port for the real-time display,this paper designs a serial communication interface based on the LabVIEW,and performs data self test and data reception test,which verifies the correctness of the design.This paper completes the design of the high-precision attitude measurement system and the development scheme of the system hardware and software,and carries on the whole system test so that the feasibility of the hardware and software scheme is verified.