基于24位置的MEMS惯性传感器快速标定方法

针对微惯性测量单元原始输出信息受零偏、标度因数、非正交误差等误差项干扰影响测量精度的问题,提出一种无需借助高精度转台的MEMS IMU快速原位标定方案。在分析MEMS惯性传感器输出特性的基础上建立传感器误差模型,利用六面体夹具设计IMU 24位置连续转停标定方案,以重力及各次旋转角度为参考信息完成传感器误差标定。针对加速度计零偏、标度因数、非正交误差9个参数构造标定模型,采用牛顿法估计误差参数最优值,考虑陀螺仪零偏与标度因数6个误差参数,利用最小二乘法计算误差参数最优估值。分别进行加速度计、陀螺标定补偿实验,实验结果表明,提出的MEMS IMU快速原位标定方法能快速得到传感器误差参数,提高了输出数据精度。

A Fast Calibration Method for MEMS Inertial Sensors Based on 24-Position

Aiming at the problem that the original output information of the micro inertial measurement unit is affected by the errors of bias, scale factor and non orthogonal error, a fast in situ calibration scheme of MEMS IMU without high precision turntable is proposed in this paper. Based on the analysis of the output characteristics of MEMS inertial sensors, the sensor error model is established. The calibration scheme of IMU 24-position is designed by using hexahedron fixture. The sensor error calibration is completed by using the gravity and each rotation angle as reference information. A calibration model is constructed for 9 parameters of accelerometer bias, scale factor and non orthogonal error. The Newton method is used to estimate the optimal value of error parameters. Considering the 6 error parameters including gyro bias and scale factor, the optimal estimation of error parameters is calculated by least square method. The calibration compensation experiments on the accelerometer and gyro are carried out respectively. The experimental results show that the proposed fast in situ calibration method for the MEMS IMU can quickly obtain the sensor error parameters and improve the output accuracy of the data.