In-Motion Attitude and Position Alignment for Odometer-Aided SINS Based on Backtracking Scheme

Abstract

In-motion alignment of navigation-grade strapdown inertial navigation system (SINS) combined with odometer (OD) is one of the challenging issues for the land vehicle navigation, while most current in-motion alignment methods still rely on the measurements of the global positioning system or only aim at improving the attitude alignment, thus neglecting the position alignment. Thus, one of the main obstacles during the in-motion alignment for SINS/OD is to autonomously and simultaneously obtain the high-precision attitude and position within specified time. In this paper, an in-motion alignment scheme based on the backtracking scheme is presented to solve this problem. The proposed method consists of two steps. First, an improved optimization-based coarse alignment (IOBCA) is employed to obtain the attitude and position with reasonable precision, and the gravity deflexion error projection in inertial frame caused by the positioning error is diminished, which contributes to better alignment results for the subsequent process. Second, initialized with the alignment results provided by IOBCA, a backtracking-scheme-based fine alignment combined with the Kalman filter is investigated to make a further improvement in the precision of attitude and position, during which the known initial binding position and zero velocity have been utilized again. The car-mounted field experimental results illustrate that the proposed method can not only autonomously improve the precision of attitude within a short time but also simultaneously achieve the position with high precision. INDEX TERMS In-motion alignment, strapdown inertial navigation system (SINS), odometer (OD), backtracking.

Odometer Aided SINS in-Motion Alignment Method Based on Backtracking Scheme for Large Misalignment Angles

“…where f [X(t), t] can be shown on the basis of the formula (9),(13), (15), (16), (24) and (26). G(t) is the noise matrix; w(t) is the system process white noise with the power spectral density Q(t).…”

“…Chang et al utilized attitude estimation based alignment method for OD aided SINS [14]. Sun et al further improve the OBA [16] method on the basis of the known initial information including initial binding position and velocity.…”

“…Li et al proposed an online calibration and compensation of total OD error in SINS/OD system [19]. In [16] a continuous linear 16-dimensional SINS/OD integrated model was utilized in fine alignment. Few researches were about the nonlinear model of SINS/OD system, therefore further improvements of the nonlinear model would be worthwhile.…”

In-motion initial alignment method using Cayley–Kalman filter on special orthogonal group

“…This matrix decomposition method was also used in an alignment algorithm for land odometer-aided SINS in Ref. 18.…”

In-Motion Alignment Method of SINS Based on Improved Kalman Filter under Geographic Latitude Uncertainty

“…However, this alignment has high requirements on the environment, which greatly reduces its agility and its anti-strike feature. Because the in-motion alignment method can effectively improve the carrier's maneuverability under the premise of ensuring the alignment accuracy, this technology has received more attention recently [3][4][5][6][7][8]. The traditional initial alignment method of the SINS is generally carried out under the condition that the geographical location (mainly refers to latitude) is accurately known.…”