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 degrees, 0.006 degrees and 0.6 degrees respectively.