MEMS惯性测量单元航姿更新中的测量误差估算方法

利用MEMS惯性测量单元测量载体的航姿,需要借助精密转台且较难精确估算测量误差,导致成本高误差大.针对该问题,该文利用卡尔曼滤波器在线估算载体的姿态和陀螺仪的偏置,提出一种优化航姿精度的测量误差估算方法.通过推导测量误差的数学模型,分析航姿精度随测量误差变化的关系,得到最优航姿时的测量误差值.采用一种MEMS惯性测量单...

Estimation Method of Measurement Errors in MEMS Inertial Measurement Unit Based Orientation Update

When updating body’s orientation by using Micro Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU), a precision turntable is needed and measurement errors are difficult to be estimated accurately, which cause high cost and large error. Based on the problem, both body’s attitude and gyroscope’s bias are estimated in field by a Kalman filter, an estimation method of measurement errors is proposed for improving orientation’s accuracy. Measurement errors for the optimal orientation’s accuracy are obtained by deducing the measurement errors’ mathematical model, and analyzing the relationship between orientation’s accuracy and the variations of measurement errors. By using a MEMS-IMU, the body’s orientation is measured when it keeps movement at a constant speed and in arbitrary trajectory for 5 minutes. Experimental results show the orientation after optimization is consistent with the referenced orientation, and pitch, roll and yaw during the last quiescent period deviate from the reference values only by 0.008°, 0.006° and 0.6° respectively.