Observability of INS/OD Integration with Rotating MEMS IMU: A Global Perspective

In absence of Global Navigation Satellite System (GNSS), the vehicle tests have demonstrated that the accuracy of Inertial Navigation System (INS) can be improved by the /Odometer (OD). To further improve the accuracy of integrated INS/OD system, this paper studies an approach by rotating the inertial measurement sensors. The test results show that mechanism of rotating INS is more cost-effective than use of more accurate inertial sensors, in particular case of micro-electromechanical inertial sensors. Design of a complete rotational navigation system requires rigorous mathematical modeling and experimental analysis, by which an efficient rotation scheme can be achieved to optimize the performance of such navigation systems. This paper attempts to explore the changes brought by rotational INS to the classic INS/OD integrated navigation system. The relationship between the states of a rotating INS is investigated from the perspective of global observability instead of the error state approach. The outcomes of the research are helpful to deeply understand the rotating navigation system, in terms of providing guidance for the rotation scheme to refine such systems further.