Abstract:

A vacuum filtering correction method for on SINS (Strap\|down inertial navigation system) based on specific force observation is introduced in contrast with traditional method. This method can be used to solve the problem of separating the accelerometer drift and scale factor errors accurately during the ground alignment. Besides, it can also be used to correct the navigation system errors. Taking the advantage of the vacuum information, system state equation and measure equation are established by using the specific force message of the accelerometer. The observability analysis of instrument and system errors is taken. Online filtering method of instrument and system errors is given. The simulation results show that the vacuum filtering method can be used to separate the accelerometer drift and scale factor errors and to correct system errors including attitude, velocity and position errors. The method plays a significant role in improving navigation performance of SINS in reality.

Key words: Inertial navigation, Kalman filter, Vacuum correcting, Strap down inertial navigation system (SINS)