Strapdown Inertial Navigation System Simulation

The characteristic of the SINS-Strapdown System is that the inertial elementswhich are fixed on the carrying body straightway can apperceive the information ofbody's angle and linear movement. This system usually works in abominablesurroundings. This system adopts mathematical platform. That's to say, we calculatethe attitude matrix promptly by using computer, found virtual platform by mathmethod. So the renewed arithmetic of the attitude and navigation is in the core part ofthe system. And what's more, it effect the precision mainly. Especially to the missilein highly dynamic situation, the renewed arithmetic of the attitude is a crucial factorthat can determine if the system runs normally.This paper first elaborated the principle of SINS, some interrelated information,and the affect of renewed arithmetic to the system's precision. Then, we studied thequaternion in traditional renewed attitude arithmetic. The quaternion is simple, andwhen run it into computer, it's time saving. So, this arithmetic is often adopted byengineering. However, the quaternion brought unexchangeable error inevitably. Whenthe carrying body moves in highly dynamic situation, the error would become larger.So we should take effective measure to get over it. In this paper, we adopted therotation vector method, made use of the rotation vector differential equation instead ofthe quaternion differential equation to modify the integral of angle speed vector.Beside of this, we simulated the SINS arithmetic in MATLAB. The results proved it'sfeasibility. We also designed a software based on the graphic programlanguage-LabVIEW. Through simulating, we verified the feasibility of the softwaretoo.