The Design Of High Precision MEMS INS/GNSS Integrated Navigation System

Strapdown inertial navigation as a fully autonomous navigation method plays an irreplaceable role in the military and civil fields.With the development of MEMS(MicroElectro-Mechanical System)devices,inertial navigation system with high precision,low cost,small volume of the continuous emergence of application,to satisfy the market expanding.This paper use the quartz tuning fork gyroscope,quartz vibrating beam accelerometer inertial components to design a high precision of navigation system with GPS,geomagnetic sensor combination,can meet the requirements of UAV,aerial bomb system navigation requirements.The main work of this paper are as follows:(1)System hardware platform.The navigation computer use FPGA as a data acquisition processor,sensors data is sent to the DSP which is used to navigation solution.To complete the system structure,design of power supply circuit,complete the circuit of FPGA and DSP minimum system design,complete the communication design of the sensor data acquisition module design,completed the FPGA and DSP dual processor inside the FPGA,completed the DSP internal bottom drive design.(2)Sensors error model and compensation.Analysis of the error source of MEMS inertial sensors,to establish the error calibration model and use three axis turntable indoor to calibration the sensors.Using the relations between the system temperature and temperature control box to compensation influence of inertial sensors zero bias parameter change.In order to reduce the error geomagnetic sensor,geomagnetic compensation method is proposed based on an ellipse or ellipsoid fitting.(3)Integrated navigation system algorithm.MEMS inertial navigation system(MINS)internal error of integral operation will increase with the passage of time.In order to obtain real-time navigation information system,we use GPS course and speed and other information to correction the MINS velocity and position information.To establish integrated navigation system filter model and gives the implementation method of the system EKF filtering algorithm,and simulation analysis.(4)The testing of system accuracy.The static accuracy test and swing experiment and dynamic experimentafter finishing the practical system.The test results for the static level error is less than 0.1 degrees,the dynamic swing horizontal error is less than 0.2 degrees,level error in a car test is less than 0.5 degrees.Azimuth error before combination is less than1 degrees,azimuth error after combination is less than 0.5 deg.