基于模值估计的三轴磁力计标定方法研究

现有的三轴磁力计标定方法大都是对采样数据进行归一化,然后利用样本数据求解参数.为了提高标定算法的通用性和有效性.提出了一种改进的标定方法,首先将磁力计所处位置磁场向量的模作为误差模型参数,然后对其进行估计算法设计,接着提出一种两步标定方法进行参数初值的选取,然后应用Levenberg-Marquardt方法进行磁力计标定算法设计.仿真和实验结果表明,本文所提算法对类似的三轴传感器具有通用性,不依赖于传感器的观测向量,同时能够对所观测向量的模值进行精确的估计,可以标定三轴磁力计的安装误差、静态灵敏度误差和零位误差,标定过程简便,适用性广.

Research on Calibration Methods of Three-Axis Magnetometer Based on Vector Norm Estimation

In view of calibration methods of three-axis magnetometer, most calibration methodsuse the normalized magnetic field vector to calibrate three-axis magnetometer. In order to improve the generality and effectiveness of calibration methods,a two-step calibration method is proposed. In this work,the error model of three-axis magnetom-eter uses the magnetic field vector norm as a parameter. First step is used to get the initial parameters,then second step is used to solve nonlinear least squares problem with the initial parameters. Simulation results show that two-step calibration method can improve the convergence of Levenberg-Marquardt method. This method does not depend on the observed vector,and is also applicable to other three-axis sensors with the same error model. And experiment results show that this method can correctly and effectively compensate the misalignment errors,null shift errors and sensitivity errors of the three-axis magnetometer. And the magnetic field vector norm is relatively precise.