Coarse Alignment of Strapdown Inertial Navigation System Based on LMS Adaptive Filtering

Coarse alignment of SINS (Strapdown Inertial Navigation System) is a process to determine the Angle between the carrier coordinate system and the navigation coordinate system. Using the output values of gyroscope and accelerometer to construct attitude transfer matrix by the method of constructing new vectors from orthogonal vectors. However, in practice, the output of the gyroscope and the accelerometer are often interfered by the outside world, resulting in the change of the measured value of the angular rate output by the gyroscope and the perceived gravity acceleration by the accelerometer [1]. Furthermore, the attitude transfer matrix changes and the attitude Angles are no longer accurate. In this paper, an adaptive filter algorithm based on Least Mean Square (LMS) is used to deal with device noise reduction to minimize the influence of external interference on device measurement accuracy. Simulation results of coarse alignment show that the device error is obviously reduced and the precision of coarse alignment is greatly improved.