An Investigation on MEMS IMU Error Mitigation Using Rotation Modulation Technique

Shuang Du, Wei Sun, Yang Gao

Abstract:	As the MEMS (Micro-Electro Mechanical Systems) IMU (Inertial Measurement Unit) outputs are corrupted by significant sensor errors, the navigation errors of the MEMS-based inertial navigation system accumulate very quickly, and so does its integrated system with GNSS (Global Navigation Satellite Systems) when GNSS measurements are not available. This paper proposed a rotary INS (Inertial Navigation System) to mitigate the navigation errors caused by the significant MEMS inertial sensor errors by rotating the IMU. A rotary INS is an inertial navigator in which the IMU is installed on a rotation platform that rotates the IMU following pre-defined rotation schemes. As the proper IMU rotation can average out the sensor errors without the need for external information, such technique had been widely accepted marine navigation for submarines and warships. However it has not been investigated for low-cost MEMS IMU systems. In this research, different IMU rotation schemes (rotation about X, Y and Z axes) are employed and the mitigation of navigation errors caused by inertial sensor errors through IMU rotations is analyzed mathematically. Simulations are conducted to verify the error mitigation analysis in rotary INS. By using a tri-axial rotation table, the prototypes of the rotary INS are developed based on two MEMS IMU, namely, MTi-G and NAV440, respectively. The static tests are conducted and the results indicate that although the rotation of IMU can mitigate the navigation errors caused by inertial sensor errors, it also motivates additional sensor errors due to the gyro scale factor and installation errors, which results additional navigation errors. Therefore, a calibration of these sensor errors for MEMS-based rotary INS is required.
Published in:	Proceedings of the 27th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2014) September 8 - 12, 2014 Tampa Convention Center Tampa, Florida
Pages:	1822 - 1838
Cite this article:	Du, Shuang, Sun, Wei, Gao, Yang, "An Investigation on MEMS IMU Error Mitigation Using Rotation Modulation Technique," Proceedings of the 27th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2014), Tampa, Florida, September 2014, pp. 1822-1838.
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