An Online Gravity Modeling Method Applied for High Precision Free-INS.
For real-time solution of inertial navigation system (INS), the high-degree spherical harmonic gravity model (SHM) is not applicable because of its time and space complexity, in which traditional normal gravity model (NGM) has been the dominant technique for gravity compensation. In this paper, a two-dimensional second-order polynomial model is derived from SHM according to the approximate linear characteristic of regional disturbing potential. Firstly, deflections of vertical (DOVs) on dense grids are calculated with SHM in an external computer. And then, the polynomial coefficients are obtained using these DOVs. To achieve global navigation, the coefficients and applicable region of polynomial model are both updated synchronously in above computer. Compared with high-degree SHM, the polynomial model takes less storage and computational time at the expense of minor precision. Meanwhile, the model is more accurate than NGM. Finally, numerical test and INS experiment show that the proposed method outperforms traditional gravity models applied for high precision free-INS.
School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100083, China. by1217133@buaa.edu.cn.|Inertial Technology Key Laboratory of National Defense Science and Technology, Beihang University, Beijing 100083, China. by1217133@buaa.edu.cn.
Jing
J
Wang
School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100083, China. yanggongliu@buaa.edu.cn.|Inertial Technology Key Laboratory of National Defense Science and Technology, Beihang University, Beijing 100083, China. yanggongliu@buaa.edu.cn.
Gongliu
G
Yang
School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100083, China. buaa_lijing@buaa.edu.cn.|Inertial Technology Key Laboratory of National Defense Science and Technology, Beihang University, Beijing 100083, China. buaa_lijing@buaa.edu.cn.
Jing
J
Li
School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100083, China. by1317110@buaa.edu.cn.|Inertial Technology Key Laboratory of National Defense Science and Technology, Beihang University, Beijing 100083, China. by1317110@buaa.edu.cn.
Xiao
X
Zhou
complexity analysis; high precision free-INS; online modeling; polynomial model
Sensors (Basel). 2014 Sep 03;14(9):16322-42
25192311
Sensors (Basel). 2015 Oct 16;15(10):26212-35
26501281