惯性测量组件离心机标定及误差分析方法

针对传统惯性测量组件(IMU)标定方法不能根据加速度计测量量程提供足够大的信号激励,并且现有离心机标定方法未考虑IMU在离心机上的安装位置偏差的问题,提出了一种基于离心机的IMU标定及误差分析方法. 将IMU按照6个基准位置安装于离心机上,通过离心机在水平面内旋转,为IMU提供角速度激励和加速度激励. 通过对IMU的输出进行旋转积分,可以消除地球自转以及离心机不水平带来的谐波影响,获得IMU的输出方程. 在不考虑IMU在离心机上安装的位置偏差角的情况下,采用线性最小二乘法求解;在考虑IMU偏差角的情况下,采用牛顿法求解,可以标定出IMU的标度因数、安装误差、零偏、IMU偏差角等共计27个误差系数. 建立了标定方案中的离心机控制模型和误差传播模型,并对模型进行了仿真验证. 仿真试验表明,该标定方法步骤简单,输入激励可调,标定结果误差可控. 

A Calibration and Error Analysis Method for IMU Using Centrifuge

In conventional calibration of inertial measurement unit (IMU), sufficient signal excitation according to accelerometer's measuring range cannot be provided, moreover, current centrifuge-based calibration method doesn't take the IMU's orientation error on centrifuge into consideration. In this paper, a calibration and error analysis method for IMU using centrifuge was proposed. The IMU was installed on centrifuge in six positions and rotates with centrifuge in horizontal plane. Both angular velocity and acceleration excitations were provided by centrifuge. After revolution integration of the IMU's output equations, harmonic components brought by rotation of the earth and non-levelness of centrifuge can be eliminated, thus the IMU's output equation can be acquired, according to which error parameters including scale factor, misalignment, bias and orientation error can be calculated. In case of ideal horizontal installation of the IMU on centrifuge, linear least squares method was used; when taking orientation error into consideration, Newton method was used. Both the control model of centrifuge and the error propagation model were developed. Finally both models were simulated. Experiment results indicated that this calibration method was simple to implement, the input excitation can be modified, and the calibration error can be controlled.