Filter Designed for GPS-Aided Inertial Navigation System Based on Linear Accelerometers

W. Junwei, L. Jinfeng, Z. Yunan, Y. Na

Abstract:	The motivation for developing a gyroscope-free navigation system is that low-cost gyroscopes lack the accuracy needed for precise navigation application and can not achieve the required levels of precise in the near future. A precise micro-machined accelerometers, on the other hand, is more affordable. Also, less fundamental physical constraints inhibit the precision of micromachining accelerometer than that of gyroscopes. Therefore, most efforts tend to develop a INS which is only based linear accelerometers and called gyroscopefree inertial navigation system, in short GF-INS. It is well known that the least number of sensors detecting the motion of body is six which corresponds to the six independent parameters describing the rigid displacing and rotating in space. Based on the theory mechanics, all of the parameters of rigid motion may be obtained by the least six linear accelerometers distribute from centroid. It is known that the differential equation of angular and linear velocity is nonlinear, the extended Kalman filter (EKF) will be adopted to estimate the angular velocity errors. The EKF is the optimal least squares estimators for the system described by the nonlinear state-space model and well adaptive to our problem. In this paper, a configuration of six accelerometers located will be presented and all of the detecting axis of accelerometer parallel to coordinate axis. The differential equation of angular velocity and linear velocity will be resolved based on the six accelerometers located in the sphere scheme. The error dynamic equation of GF-INS is derived and the character of error is analyzed. The information from GPS will be taken as the reference of GF-INS and the extended Kalman filter designed to estimate the GF-INS errors resulted from the accelerometer bias. Simulation will be done to know and verify the research results in this paper.
Published in:	Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006) September 26 - 29, 2006 Fort Worth Convention Center Fort Worth, TX
Pages:	2208 - 2213
Cite this article:	Junwei, W., Jinfeng, L., Yunan, Z., Na, Y., "Filter Designed for GPS-Aided Inertial Navigation System Based on Linear Accelerometers," Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006), Fort Worth, TX, September 2006, pp. 2208-2213.
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