Application of adaptive FLP filter to ring laser gyro IMU calibration

Ring laser gyro inertial measurement unit (IMU) encounters the problem of relatively large stochastic noise because of the strenuous dithering motion. The conventional calibration method eliminates the impact on the stochastic noise by extending the measurement time, which undoubtedly reduces the calibration efficiency. To solve the problem, the adaptive forward linear prediction (FLP) filter is adopted to suppress the stochastic noises of ring laser gyro IMU calibration data and improve the calibration accuracy of the system with small amount of calibration data. Firstly, the original data is acquired from the four-position rotation calibration experiment. Secondly, the calibration data is de-noised by the adaptive FLP filter to improve its signal noise ratio (SNR). Finally, the calibration parameters are calculated with the de-noised data. The experimental results show that the stochastic noises of calibration data are de-noised effectively by the adaptive FLP filter, the SNR of the signal is improved, and more accurate calibration parameters are acquired with small amount of calibration data, which enhances the navigation accuracy of the system.