Shock Absorber Deformation Under The Conditions Of Mechanically Dithered Laser Gyro Strapdown Inertial Navigation System Calibration Method For Optimization Studies

The article studies on the calibration method of dithering laser gyro strap-down inertial navigation system (DLNS) while it installs shock-absorption. Installing shock-absorption can decrease the error brought by the laser gyro's dithering when calibrates DLINS, and it also can eliminates the error resonated by DLINS and turn table, but it also brings in the error which is made by the distortion of the shock-absorption, which would reduce the precision of calibration, especially gyro's constant error. The article optimizes the classical calibration route while installs shock-absorption to improve the DLINS's precision. The author studies:(1) Calibrating the inertial measure unit separately , Calibrating the inertial measure unit separately is a classical calibration method. The article analyses the effect of the dithering on the output of the IMU, then put forward the calibration method's optimization based on the DLINS. While installing the shock-absorption it can improve the calibration precision with four places;(2) Calibration in navigation's state, After calibrating the parameter of IMU, we use Kalman filter to calibrate the DLNS in navigation's state, this needs to design the optimization's route. It doesn't need to consider the distortion of the shock-absorption, so the result is not influenced by it, this can calibrate the error's parameter in high precision;(3) Gyro's drift is the important factor which influences the precision of DLINS, so its compensation is an important factor in DLINS. Commonly, gyro's drift especially optical gyro's error varies with time in one-order and second-order, so how to compensate it is necessary. The article puts forward the drift modal and reason the arithmetic that compensating it. The experiments show that the gyro's drift is in existence and must be compensated.The article studies on the calibration of gyro's constant error and the compensation's method of gyro's drift, it put forward a new approach to study and improve the DLINS's precision.