Research On Calibration Technology Of Three-axis MEMS Accelerometer

With the development of micro-nano processing technology and the progress of integrated circuits,Micro-Electro-Mechanical Systems(MEMS)has received more and more attention in the field of scientific development.Among them,MEMS inertial navigation technology is widely used in modern navigation disciplines and tactical weapons.The three-axis MEMS acceleration sensor is one of the core components of this technology,the measuring accuracy directly affect the positioning accuracy of the whole navigation system.The high precision calibration scheme of three axis accelerometer has become an essential part of ensuring the high-precision design of the navigation system.In this paper,the calibration method of the three-axis MEMS accelerometer is researched.The research goal is to find a better calibration scheme and calculate the various error parameters of the three-axis MEMS accelerometer more accurately to improve the accelerometer after compensation the purpose of measurement accuracy.Based on the research objectives of this article,the main research content of this article mainly includes the following parts:1.Research on calibration technology.Investigate the design and research progress of the three-axis MEMS accelerometer at home and abroad,as well as the calibration form and progress of the three-axis accelerometer.It is pointed out that the calibration accuracy of the three-axis accelerometer depends on the calibration mathematical model,calibration experiment scheme and parameter solution method.2.Establish the calibration mathematical model.The error of the three-axis MEMS accelerometer is described systematically,and the calibration mathematical model is established.The traditional three-axis accelerometer calibration mathematical model usually only considers the three-axis accelerometer zero offset,scale factor error and installation error.In this paper,the lateral sensitivity of each sensitive axis of the three-axis accelerometer is also considered when establishing the three-axis accelerometer calibration mathematical model.Consider it as an error parameter,and establish two sets of calibration mathematical models.3.Set up an experimental platform,and use an FPGA board as a data acquisition card to complete the programming and debugging of the acceleration data acquisition of the three-axis MEMS accelerometer ADXL362.Analyze and compare the characteristics of the sensor,and determine the calibration experiment scheme according to the existing experimental conditions.In this paper,the six-position calibration method,the 12-position calibration method and the centrifuge calibration method are used to measure the acceleration data respectively.Combined with the established calibration mathematical model,the advantages and disadvantages of these methods are compared through subsequent calculations3.Data collection for calibration experiment.An experimental platform was built,and an FPGA development board with a cyclone IV chip as its core processor was used as a data acquisition card to complete the programming and debugging of the acceleration data acquisition of the three-axis MEMS accelerometer ADXL362.This article uses six-position calibration method,twelve-position calibration method,and centrifuge calibration method to measure the output acceleration data of the three-axis accelerometer.4.Experimental data analysis.The maximum likelihood parameter estimation method is used to calculate the parameters of the six calibration schemes used in this paper.Each scheme parameter is used to compensate a set of triaxial accelerometer output data with known input and output respectively,and the parameter compensation errors of each calibration scheme are compared with the actual errors.The experimental results show that,compared with the traditional calibration mathematical model,the error mean and variance of the output compensation value of the accelerometer obtained by the proposed calibration mathematical model considering the lateral sensitivity of each axis of the three-axis accelerometer are smaller,that is,the output accuracy of the three-axis accelerometer is higher and the stability is better.The validity of the proposed calibration scheme is proved...