Research On Key Partial Technique Of Mechanically Dithered Ring Laser Gyro Compass

Although the research of compass has been already matured, only a few institutions in our country can develop middle or high precision North-seeking system. The task of this paper is to develop a higher precision North-seeking system by using high precision mechanically dithered ring laser gyro(MDRLG) and choosing reasonable north-seeking project and filter technique.The configuration and principle of North-seeking system are discussed, and the mathematic model of Multi-position is also derived in this paper. After Multi-positon project errors are analysed in detail, Four-position north-seeking project is introduced and the primary parameters of key inertia components are determined.In order to improve north-seeking precision, Kalman filter is introduced to process the MDRLG signal, which can reduce the effect of random drift and external disturbance. The building block design of software which is compiled by C language is discussed in detail, and the software flow is presented.A series of experiments have been carried out on the north-seeking system in the laborary of our institute, the results are as follows: North-seeking time is about 5minutes, north-seeking repeatablity error is about 0.25mil ( 1σ), the zimuth angle error is less than 0.33mil ( 1σ).The results show that the choice of north-seeking project and data processing method are reasonable, and the required precision has been achieved.