Application of kinematic constraints for smart INS/DVL integrated navigation

Inertial Navigation System (INS) is widely used for underwater navigation. As its navigation errors increase with time, Doppler Velocity Log (DVL) is usually utilized to assist the INS. However, due to the complex underwater environment, DVL may fail during the missions. To deal with this problem, the kinematic constraints which are usually employed for land vehicle navigation are adjusted for underwater vehicles. In addition, a nearest extrapolation approach is proposed to predict the vehicle’s forward velocity. If the DVL malfunction happens, the kinematic constraints model can be employed to limit the error growth of the navigation system. From experimental results, it is clearly shown that the proposed method is able to limit the error growth of the INS and performs much better than pure INS navigation.