A Large Misalignment Angle Initial Alignment Method of SINS Based on Strong Tracking Sparse Grid Gauss Hermite filter

The large misalignment angle error model of strapdown inertial navigation system (SINS) is a kind of nonlinear Gauss error model. The Gauss Hermite method can approach Gauss integral with any precision, and achieve high precision filtering effect. The number of Gauss Hermite integral points is exponentially related to the dimension of nonlinear system. In the process of real-time filtering, a large number of integral points of multidimensional system may lead to dimension disaster. According to the initial alignment error model of SINS with large misalignment angle, this paper presents a strong tracking reduced dimension sparse grid Gauss Hermite filtering method, which reduces the nonlinear integration dimension through separation of the linear and nonlinear terms, further reduces the number of Gauss hermit filtering integration points by sparse grid method, and ensures the stability of the system by strong tracking method.