Research Of The High Precision North Finding Technique Using Ring Laser Gyroscope

Laser Gyroscope has been widely applied in north finder for its quickstartup、 resistance to harsh environment and high precision. Accuracy andrapidity are important technical targets of the north-finder system. The anglerandom walk(RAW) which the Laser Gyroscope works under rate biased state ismuch smaller than the dithering state. Based on this characteristic of the LaserGyroscope, main researches on the north finder using rate biased RLG are carriedout as follows:First,The basic principle of the RLG north finder is analyzed, and the errorcharacteristic of the north finder under rotation confection is derived.Second,The next,Different error characteristics are analyzed, including theRLG scale factor errors, angle sensor error, coning error, lever-arm error, andbase disturbance errors. The appropriate compensation methods and theexperimental results are laid out.The next,The software and hardware systems are designed, including thedigital signal processing circuit design, the thermostat circuit design and theupdate algorithms design of attitude and velocity. And then, based on the northfinding algorithms under Kalman filter, principle prototype is put forward.Final,On the basis of the principle prototype, the experiments are carried outunder the laboratory conditions and the outdoor car conditions. Contrasts aremade between the two position alignment under dithering state and the rotationalignment under rate biased state of the north-finder system. The alignment resultof the two positions is about30-40″(1σ) in5minutes, and the rotation alignmentis approximately12″(1σ) in5minutes. It’s verified that the proposednorth-finder system has strong anti-interference ability as the system stability of15″(1σ) based on rate biased.