Backtracking scheme for single-point self-calibration and rapid in-motion alignment with application to a position and azimuth determining system

The position and azimuth determining system (PADS) chiefly consists of an inertial navigation system and odometer. In order to improve the performance of the PADS, a backtracking scheme is proposed for odometer calibration and odometer-aided rapid alignment of PADS with a single pre-known landmark. Based on a backtracking scheme, a newly derived backward filter is presented to accomplish odometer calibration, fine alignment and positioning simultaneously by using the recorded forward data. Compared with normal methods, the proposed method can calibrate the odometer with only one pre-known landmark and lessens the environment restraints. Both the simulation and the experiment results show that the proposed method can calibrate the odometer with only one landmark and achieve good alignment and positioning accuracy in a short period of time.