Research On MIMU Automatic Test And Calibration System

Because of its small size,low power consumption,high reliability,relatively low cost,and ease of mass production,MEMS inertial measurement units have attracted the attention of various countries and have been increasingly used in military and civilian fields.However,because the device itself will produce errors during the manufacturing process,error calibration and algorithm compensation are required in the later stage to improve its measurement accuracy.The thesis aims to improve the calibration method by reducing the complexity of the calibration operation and increasing the calibration efficiency,and designs a portable MIMU test and calibration system.First of all,according to the design requirements,the overall design of the calibration system is completed,mainly for structural design,hardware control system design,and upper software design.The structure of the whole machine mainly includes reinforced chassis,small three-axis turntable,system control box,system power supply module,etc.;the hardware control system is mainly to accurately control the small three-axis turntable,which is composed of torque motors,encoders,motor drives,and PMAC motion The control card constitutes a three-loop control system of position,speed and current,and introduces the debugging method of the control system.Secondly,according to MIMU's error generation mechanism,establish its error model.The specific calibration process based on the three-axis turntable discrete calibration method and the system-level calibration method based on the Kalman filter are introduced respectively.The Kalman filter model is designed based on the error model.In order to reduce the amount of calculation and speed up the filter convergence,the idea of dimensionality reduction is adopted,and the filter model is split to establish the filter model of the gyroscope and the accelerometer to complete the error estimation.Then,it introduces the design and development of the upper-level software of the system based on LABVIEW,which mainly includes a multi-serial communication program module,which is used for MIMU data reading and communication with the PMAC motion control card;the turntable control module,realizes the multi-function control of the turntable,and can simulate some dynamics Environment to stimulate the various errors of MIMU;MIMU's attitude calculation and navigation solution modules provide MIMU attitude information and navigation information;coarse calibration and system-level calibration modules realize MIMU's data online processing and automatic calibration functions.Finally,the accuracy of the hardware control system and the functions of the upper software are tested.After the calibrated error parameters are compensated for the MIMU,the accuracy of the attitude calculation is improved.Compared with the traditional calibration system,its operation is more convenient and the calibration time is shorter.