Research Integrated Navigation System Based On MEMS Sensor

The navigation system provides the attitude information of moving carrier to the control system,which is used to realize the carrier from the start point to the target end point according to the planning path.The development of navigation system has been gradually diversified,but a single navigation system has been difficult to adopt needs of new areas of application,so the integrated navigation system which has combined advantages of different navigation system has come into being,and has gotten more research.Sensor is core of navigation system,whether it is a single inertial navigation system or GPS/INS integrated navigation system.With the rapid development of micromechanical system(MEMS)technology,MEMS inertial measurement unit(IMU)and MEMS magnetometer has begin to be widely used in integrated navigation system.MEMS sensor has small volume,low power consumption,low cost,high integration and so on,these advantages can make the integrated navigation system apply to many fields,such as mobile phone,aerial vehicle typed consumer and wearable medical equipment,and greatly expand the application of integrated navigation system.A widely used integrated navigation system based on GPS and INS may be useless when the system has no reception signal from satellite.So,in this paper we designed an integrated navigation system based on MEMS IMU and MEMS magnetometer to realize the measurement of carrier's attitude information.This paper mainly completes the following three aspects:(1)Established the error model of MEMS IMU and MEMS magnetometer,and designed the calibration system for MEMS sensor.In this paper,the principle of MEMS IMU and MEMS magnetometer is introduced first.And then established the function between the output value and the actual value according to the error parameters of IMU and magnetometer,including bias,scale and misalignment.And then designed six-side static experiment and three-axis turning experiment to get the error parameters based on the known error function.One calibration program is used in whole entire solution and calibration process which is designed by Labview software.At last,an online calibration algorithm is designed to realize the automatic calibration of the sensor in the integrated navigation system,which can useful inhibition the drift of MESM IMU.(2)The building of hardware platform for integrated navigation system and the realization of the software function.First of all,according to the designing requirements of the integrated navigation system to select hardware,the core microprocessor is STM32F407 and sensor is MPU9250.The software architecture would achieve many functions,such as the getting the original data of sensor,saving data to SD card,building communication from system to calibration program,online calibration and so on.(3)Researching and comparing for different attitude calculation algorithms.Building math model and program for commonly used calculation algorithms based on the data from SD card,including Complementary filtering,Extend Kalman Filter,quaternion solution algorithm.,and then choose the best one apply to the system in paper.Finally,confirming the attitude calculated by calibrated sensor data is more accurate than original data.