Accurate Navigation of Marine Vessel, Using the Integration of Inertial Navigation System (INS) and Global Positioning System (GPS), Applying Extended Kalman Filter

Inertial navigation is a method to determine the position, velocity and attitude of a vehicle. In these systems, three perpendicular accelerometers and three perpendicular gyroscopes are used to measure linear accelerations and angular velocities of vehicles, respectively. Using some special equations and the measured accelerations and angular velocities, the position, velocity and attitude of a vehicle can be determined. Although these systems have great advantages, some disadvantages such as the increase of error position, velocity and attitude of vehicle by the passage of time exist. These disadvantages are due to errors of inertial sensors. In this paper, firstly, a suitable error model of inertial sensors is proposed. In the following, to decrease these errors and to correct the operation of inertial navigation system; the INS is integrated with GPS. Integration of INS and GPS is done using extended Kalman filter. To this purpose, required equations and relations for integration of INS and GPS are extracted and proposed completely and illustratively. Finally, the simulation of integration of INS and GPS is presented for two different motion scenarios. The results of simulation show great improvements in characteristic of INSᣴ system in comparison to INS individually.