On initial alignment of large azimuth misalignment for SINS on the static base in Krein space

The error equation of the azimuth misalignment angle for SINS on the static base is nonlinear, and it´s an urgent problem to align it when the angle is large. This paper proposes a method for the initial alignment of large azimuth misalignment based on Krein space linear estimation. The sum quadratic constraint (SQC) for nonlinear system is obtained by using Lipschitz condition of nonlinearity. Thus proposed Krein space approach is used to tackle the estimation problem for a class of nonlinear cases. Using kalman filterof krein space robust properties, we establish a nonlinear measurement error equation in Krein space, and give a recursive formula for the measurement error estimation. The initial alignment of large azimuth misalignment is simulated Finally, a numerical example is given to demonstrate the effectiveness of the proposed approach.By the Kalman filter method in Krein space which shows that the result generated by the Kalman filter method in Krein space has effective and superior.