Research On Laser Gyro Sins Dynamic Error Test And Calibration

Strapdown inertial navigation system is a kind of inert ial navigation system widely used in military and civil, to improve the navigation precision, both in the domestic and at abroad research on the error of strapdown inertial navigation system is widely carried out. The strapdown inertial navigation error is mainly caused by the error of inertial device, at present, more researches are done on the static error of the inertial device, however, less researches are done on dynamic error. On the basis of the static error calibration method, the paper studies the dynamic error test and calibration methods for laser gyro SINS.Before calibration, this paper presented laser gyro and accelerometer dynamic error models, focusing on the generation mechanism of accelerometer dynamic error, and gave the process of building dynamic error model. Using the function of uniform angular velocity of three-axis turntable, harmonic angular velocity and angular acceleration were generated on the turntable inner shaft, a dynamic error was excited, the relations between each harmonic of gyro dynamic error and dynamic error coefficients were built, the dynamic error coefficients were got by the application of the least square method, simulations were carried out and the influential factors were analyzed to identify the accuracy, results show that in order to improve accuracy, the rotary speed and the observability the information matrix of should be considered.In order to calibrate the dynamic error of the accelerometer, system equation and observation equation were established including dynamic error coefficients of the accelerometer as a part of the state, Kalman filtering method was used to estimate the state, and to solve the problem of rounding error generated by Kalman filtering, a solution of using square root Kalman filter was presented. In order to excite the dynamic error of the accelerometers, kinds of rotation program of the turntable were designed, the simulation results show that increasing given angular acceleration can improve identification accuracy, at the same time, the identification accuracy is connected with the duration of the maximum angular velocity, but showing a non-linear relationship.