Alignment Method for SINS-Tachometer Integration Based on Reverse Navigation Algorithm

Tachometer is cheap, and it can measure autonomous underwater vehicle′s relative axial velocity to surrounding water during high speed navigation, so it becomes an auxiliary device for alignment of strap-down inertial navigation system(SINS). In this paper, a method for integrating SINS and tachometer is proposed. The data from tachometer are used to correct the infor-mation collected by inertial sensors, and the information obtained from the system is processed forward and backward alternately according to the idea of reverse solution. By increasing processing times of sampled data during the period of alignment, the alignment accuracy and performance of the system can be enhanced. Simulation result shows that the SINS-tachometer integration can realize rapid alignment and satisfy the requirement for alignment accuracy. The proposed method may be applied to an AUV formation, coordinative mission of multiple vehicles, topographic survey and seabed chart drawing, etc.