Experimental Research On North Finder Based On Rate Biased Ring Laser Gyro

High precision azimuth can be provided rapidly by the north finder based on rate biased RLG, which plays an important role in military and civil applications. The Error characteristic of rate biased RLG, is theoretically studied, same to the factors which influence the precision of north finder. Experimental research is carried out to work parameters and functions of the north finer, which is an experimental machine. The data provided by experiments is used on the next step of engineering. Main researches are as the follows.1. The error characteristic of rate biased RLG(core parts of north finder), is theoretically studied .The primary errors of rate biased RLG are bias instability error, quantification error and angle random work error. The results show that quantification error and angle random work error can be reduced, when the turn round acceleration of the rate biased equipment and rate biased period are increased.2. The factors which influence the precision of north finder are analyzed. Based on the error models of two-position sampling scheme, the errors of rate biased RLG, the rate biased parameters, the mechanical error and the demarcated error of optical norm are analyzed theoretically. The results show that the north finding precision, in short turn north finding, is primary influenced by quantification error and angle random work error. The mechanical error of north finder is a fixed error when there is no perturbation.3. The data processing method to improve the north finding precision is studied. Compared with the normal average method, moving average method can weaken the effect of quantification error and improve the precision of north finder in short turn north finding.4. The parameters of the north finer and influence of environment condition on the precision are studied by experiments. The parameters include turn round acceleration of the rate biased equipment, rate biased period and single north finding time are studied and optimized by experiments. The results show that: at the geographic latitude of 28.2o, the precision of north finder on stationary base is better than 16" after 200S. The precision of north finder is not influenced by cool starting and the repeat precision is good.5. The north finder is demarcated and the precision is proved through experiments. A experiment system is built by a theodolite and the north finder to demarcate the optical norm and compare with the geographic north (directed by Polaris). The precision of the north finder is proved by the result.