Design And Implementation Of GNSS/INS Loosely Coupled Integrated Navigation System Based On U-BLOX-M8U

The Global Navigation Satellite System(GNSS)is in full swing.Micro-ElectroMechanical System(MEMS)technology is changing rapidly.The further advancement of smart city construction puts forward higher requirements for the accuracy,reliability and continuity of navigation and positioning.Aiming at the complementary advantages of GNSS and Inertial Navigation System(INS),this thesis carries out research on key technologies of combined positioning,designs and implements a loosely coupled integrated navigation system based on M8 U.The main contents of this thesis are as follows:1)Based on the full understanding of the working mode,output information format and other content of the U-BLOX M8 U integrated development platform,this thesis designs the original data analysis software to complete the extraction of the original binary data stream.Then this thesis carries out the experimental analysis of the timedomain static characteristics of the M8 U MEMS micro-mechanical inertial sensor,and obtains the main error sources of the M8 U gyro and accelerometer.2)Different wavelet transforms are used to denoise the inertial navigation data.According to the experimental results,db5 wavelet transform is used to complete the mechanical arrangement and attitude calculation,and provide inertial navigation data for information fusion.3)Initialize the state vector,measurement vector,covariance matrix and other parameters,and use Kalman filter to fuse the solved inertial navigation data with the satellite navigation data.4)Relying on the U-BLOX M8 U hardware platform,based on the following four modules: protocol analysis,data processing,navigation solution and result rendering,a loosely coupled integrated navigation system is designed and implemented with the M8 U device.This thesis finally sets up an experimental platform based on the M8 U device to carry out car experiments.The result shows that the integrated navigation system improves the reliability and continuity of the navigation and positioning services to a certain extent,and the precision of lontitude and latitude of the satellite signal is 1.5m,1.8m.When the satellite signals are lost for 2s,10 s,and 15 s,more accurate positioning results can still be provided,the latitude and longitude precision is 1.5m?1.8m,1.59m?2.9m,1.55m?4.9m.