Static Calibration Of Piezoelectric Six-axis Accelerometer And Its Application In Inertial Navigation

The six-axis accelerometer can sense the acceleration information of the carrier in six dimensions in space,which is significant for the monitoring of the motion state of the object.At present,the research on the six-axis accelerometer is mostly on the principle level,and the practical application process is slow.One of the important reasons for this problem is that there is no unified conclusion on the calibration equipment,methods and evaluation means of six-axis accelerometer.Therefore,the research of a practical six-axis accelerometer calibration method,static characteristic index and the designing of a specific application technology is conducive to promoting its application.In this thesis,the static characteristic calibration of the IEPE six-axis accelerometer and studied its typical application technology in gyro-free strapdown inertial navigation.The measurement mechanism of accelerometer is studied in this thesis,and the sensitivity calibration theory is analyzed.Calibration equipment of six-axis vibration characteristics is studied,based on the vibration table and its vibration characteristic measurement method to design a kind of new method for sensitivity calibration,the static performance evaluation index of various channels output and its calculating acceleration results from the aspects of composite load,completed the IEPE type 6-axis accelerometer calibration experiment,The application of GFSINS based on six-axis accelerometer is developed and tested by simulation and experiment.The specific tasks completed include:(1)The system composition,structure,working mechanism and calibration method of the IEPE piezoelectric six-axis accelerometer are analyzed,and the method of using the least square method to solve the sensitivity matrix of the six-axis accelerometer is defined.(2)To study the calibration equipment of six-axis vibration characteristics and its influence on six-axis accelerometer calibration,based on the vibration table 6-axis characteristics,study the real-time acceleration measuring method of the vibration table,the actual output characteristic of the vibration table are tested,which is consistent with the theoretical analysis;The possibility and method of using its six-dimensional vibration characteristics to calibrate the sensor are studied.A new sensitivity calibration method of six-axis accelerometer is proposed.It is proved that the sensor calibration can be completed after three loading times.(3)The static performance evaluation indexes of the output of each channel of the six-axis accelerometer and the results calculated by the sensor under composite loading are studied.The algorithm of filtering and denoising under continuous acquisition is designed.An outlier detection algorithm of calibration data based on DBSCAN was proposed to screen the calibration data.The calibration and calculation software is set up.The experimental system was assembled,and the calibration experiment was completed.The evaluation index of sensor calculation error is put forward,and each static characteristic index of the system was analyzed.(4)Based on the potential application of the six-axis accelerometer in GFSINS,the working principle of GFSINS was analyzed,and the attitude calculation,speed solution,position shift solution algorithms were designed.The effectiveness of GFSINS were verified by computer simulation and indoor navigation experiments.The calibration method of the six-axis accelerometer designed in this thesis can be completed only by using the single-dimensional linear vibration platform,only one equipment is needed.Solve the problem of phase difference in the sensor output signal in the current calibration,and realize the real-time calculation.The error of the real-time solution was decreased by up to 94% compared with that of ignoring the phase difference of the signal at most.The proposed static characteristic index is.The GFSINS designed in this thesis has been proved to be effective,and a typical application scenario has been developed for the six-axis accelerometer,which provides a new scheme for GFSINS as well.