Research On The Fast North-seeking Technology Of FOG On Disturbing Base

How to seek north accurately and fast on disturbing base is a difficult and important issue. This paper mainly discusses vehicle FOG (Fiber Optic Gyroscope) north-seeking system and research on fast north-seeking under disturbance environment. The main difficulty lies in the wide bandwidth of disturbance, and north-seeking system compare with SINS (Strapdown Inertial Navigation System), has less inertial instruments and can not measured base line movement and the angle movement fully.Based on the concept of virtual inertial instruments, this paper brings forward a new anti-disturbance north-seeking algorithm.A FOG SINS has three gyroscopes and three accelerometers, and a vehicle FOG and north-seeking system only has two gyroscopes and two accelerometers. According to the actual application environment, by introducing dynamic restriction, bring forward the concept of virtual gyroscope and virtual accelerometer. So the FOG and north-seeking system can be regarded as SINS. North-seeking becomes a problem of SINS initial alignment.Based on the above ideas, this paper research on the following aspects.1. In accordance with the dynamic restriction of vehicle, the output expression of virtual gyroscope and virtual accelerometer has been presented.2. In accordance with the error equation of initial alignment on static base , a Kalman filter has designed for initial alignment, the initial alignment algorithm has been test through simulation on virtual gyroscope and virtual accelerometer.3. For better performance, active disturbance rejection control technology been applied to FOG north-seeking system, a ESO filter has been designed for SINS initial alignment, and this paper also analyzed the static error of initial alignment. Some conclusions have been reached by simulation and analysis based on the actual north-seeking system measurement data.4. This paper established a FOG output model, based on the fiber optic gyroscope characteristics.5. The north-seeking algorithm has been realized based on the Motorola MPC8260 chip PPC104 modules and the embedded operating system VxWorks. In the end the actual vehicle experiment on the FOG and north-seeking system has been carried out.