Study On Initial Alignment Of SINS

The INS (Inertial Navigation System) that based on the principle of inertia has some advantages, like independence and strong with outside noises. In the SINS/GPS integrated navigation system, when the GPS (Global Positioning System) signal was jammed, the INS can still able to provide navigation information for navigation system. SINS is a strap-down inertial navigation system. It makes the inertial component connected to carrier, and uses a computer to processing the information from inertial component, then use the information to solute navigation parameters. Compared with the inertial navigation system with platform, SINS removed the gyro stabilized platform, dramatically reducing its cost, and it can use the redundancy technology to improve its reliability. Therefore, SINS has wide application in low-cost navigation system.SINS need the initial navigation parameters, such as initial position and velocity. The attitude matrix also needs to be amended, to help the computer make geographic coordinates which was calculated and the true geographic coordinates overlap as much as possible. This is the work of SINS initial alignment. We need to study the process of SINS initial alignment to improve its speed and accuracy.The main work of this paper is the study on stationary-base SINS initial alignment. Another part is the study on moving-base initial alignment which with line movement.Paper is organized as follows:First, starting from the working principle of SINS, and gives the error model of SINS system. Secondly, because the initial alignment needs to amend the attitude matrix, so we describe four different Kalman filter. Then introduce the stationary base alignment process. Two experiments using Kalman filter, one for small azimuth misalignment angle and the other for small azimuth misalignment angle. Finally, gives an experiment for moving-base initial alignment with line movement.