Analysis of the Fading Factor of an Adaptive Fading Kalman Filter under Ramp GNSS Fault Conditions

抄録

A GNSS fault detection method using an adaptive fading Kalman filter is proposed for detecting GNSS faults such as step- and ramp-type bias error in pseudorange measurements. The fading factor of the filter is used as a detection parameter. In order to detect the GNSS fault signals regardless of the GNSS fault type, the proposed method is based on a single base station that has a fixed location and is already known. In the simulations, the different fault signal types are represented by the ramp bias error and the step bias error of the pseudorange. The change in the fading factor according to the bias error is quantitatively analyzed, and a detection threshold is established to detect the GNSS fault signal by analyzing the change in the error covariance. In addition, the value of the fading factor is applied to adjust the Kalman gain and the effect of the fault signal is mitigated by controlling the Kalman gain of the filter. The performance of the proposed fault detection method is evaluated by simulations, and the results thereof confirm that this method can detect each channel affected by fault signals when GNSS faults occur.