Research Of Systematic Calibration Method For RLG Strapdown Inertial Navigation System

Navigation accuracy of the ring laser gyro strapdown inertial navigation system(RLG-SINS)can be greatly degraded by its system errors.As a result,calibration and compensation of these errors are needed before the system is put into use.In this paper,error parameter model of RLG-SINS and calibration method were studied.The contributions of this paper is stated as follows:The commonly used parameters and coordinate system of RLG-SINS was defined.According to the inertial device general error model,a simplified RLG-SINS error model was established.A ten-position calibration method was designed and the relationship between the observation parameters and the system error parameters was derived after rotating the system according to the plan.It was shown that the ten-position method is well capable of calibrating error parameters of the designed error model.The relationship between observation parameters and error parameters was also established based on observation.A 33 D Kalman filter was designed based on the system error equations.The stability of the calibration method was verified through both simulation and calibration experiments three times.By comparing the experiment results,the proper interval-time is obtained.To verify the effectiveness of the method,the navigation deviation is tested with post-compensated data.The coning-motion effect and the way it affected the calculation of attitude and velocity is studied.The analysis showed that excited by the coning-motion,the calculated attitude errors would increase linearly with time with the existence of the scale factor errors and installation errors.A method of calculating these error parameters was presented.By simulation,it was verified that the calibration capability of coning-motion plan could effectively calibrate the gyro installation errors and scale factor errors.These results will contribute to the future study of the combination of coning-motion and original.