Strap-down Inertial Navigation System Self-aligned Technology Research And Simulation

Depending on the independent features, Inertial navigation widely used in various military aerospace navigation, has become an important mainstream missile navigation system. Alignment of Inertial Navigation System is one of the important technologies of inertial navigation. In today’s modern warfare, missile is a mark to evaluate a nation’s military force. And, the most important indicator of the missile is attack precision. Initial alignment technology which contributes to improve attack precision has become an important research topic in modern military doctrine. Essence of Inertial Navigation System is integral calculation, initial alignment can provide missile guidance systems for the integral operation posture, speed, position initial value. As one of the main sources of navigation error, Initial alignment error will make difference on the attitude, speed and position of the missile, so the initial alignment study is particularly important.In this paper, the research is a program of SINS based on the initial alignment. The speed and alignment accuracy of the initial alignment are two important indicators, research on SINS initial alignment contributes to shorten the missiles alignment time, at the same, enhance rapid response capacity, improve attack precision. This paper analyzed the two states SINS may be in, that is stationary base and shaking base, In the study of the stationary base, it divided into coarse alignment and fine alignment two stage, in coarse alignment stage by contrasting analytic coarse alignment and a correction coarse alignment, a correction coarse alignment proved to be higher accuracy; in fine alignment phase, Kalman filter algorithm under stationary base system alignment, fine alignment can be achieved. In the shaking base alignment, by aligning inertial system of SINS rough alignment can quickly achieve the alignment; in fine alignment phase, EKF, UKF Two kinds of nonlinear filtering algorithms rock base to achieve precise alignment.Simulation data show that under stationary base Kalman filtering to achieve alignment of the missile launch speed and accuracy required; in the shaking base, UKF on the alignment accuracy and speed can meet the alignment requirements.