Study on integration of FOG single-axis rotational INS and odometer for land vehicle

Obtaining the land vehicle's position, azimuth and attitudes autonomously and accurately is significant for vehiclebased weapon's combat effectiveness. High performance inertial navigation system (INS) can provide high precision attitudes and azimuth reference information, however, it is usually very expensive. In addition, due to gyroscope drifts and accelerometer biases, INS navigation errors would diverge with time. To solve the problem, this paper proposed an integrated positioning and orientation method based on the FOG single-axis rotational INS (FRINS) and the odometer (OD). The proposed method adopted the rotation modulation technique to suppress the inertial sensor errors, particularly z-axis FOG drift, by which the navigation accuracy, especially the azimuth accuracy, can be improved. At the same time, the proposed method integrated the FRINS with OD to suppress INS error's divergence with time. Combining the above rotation modulation technique and the integration of FRINS and OD, the proposed method could improve the integrated system positioning and orientation accuracy as well as reduce the integrated system cost. This paper presented the FRINS/OD integrated navigation system configuration, established the FRINS/OD integrated system errors model, and then verified the performance of proposed method by simulations. The results show that the proposed method could achieve positioning accuracy of 0.03% (of total traveled distance) and orientation of ±20, respectively, using rotational INS with FOGs of 0.1°/h and accelerometers of 500 ug.