基于极大似然估计的惯性测量组合标定方法

摘要

针对测试设备或平台框架转角误差( ASE)较大的情况,提出了一种用于惯性测量组合(IMU)标定的新方法.该方法采用相互正交的惯性器件输出的平方和作为观测信息,并以重力加速度ga和地速ωie的幅值平方作为参考基准来标定工具误差系数,这样能够消除ASE对标定结果的影响.同时针对误差项系数也较大的情况,给出了一种基于极大似然估计(MLE)的辨识方法.仿真分析了各误差系数的可观测性,并验证了辨识方法的有效性.%A new method for calibration of inertial measurement units (IMU) under the circumstances of large angle-setting errors (ASE) of test equipments or platform' s gimbals is presented in the paper. The method uses the quadratic sum of three orthogonal instruments' outputs as the observation quantity and the magnitude squares of gravitational acceleration ga and earth rate ωie as the reference to calibrate the instrument errors, which can help to eliminate the effects of angle-setting errors on the calibration results. Furthermore, an identification method based on maximum likelihood estimation ( MLE) is given for larger error coefficients. Finally the observability of error coefficients is analyzed by the simulations and the effectiveness of the proposed method are verified.