Measurements Discarding Strategy for Adaptive Kalman Filter in GNSS/IMU Integration

Innovation-based adaptive estimation(IAE),which is one of the proved AKF algorithms and can improve the accuracy of GNSS/IMU combined navigation system,is more likely to be subjected to bias and non-convergence with degraded measurements accuracy due to GNSS signal outage or low-cost receiver.In order to maintain the performance of integrated GNSS/IMU system with the coexistence of less accurate measurements,an algorithm named IAE with measurements discarding strategy(IAE-D) is proposed in this paper.The algorithm monitors the quality of the estimations and measurements in real-time,and discards the less qualified measurements.Field test was carried out,and noise was imported to simulate different levels of measurements deterioration.Performance comparison between EKF,IAE and IAE-D has been executed with real data.The results demonstrate that IAE-D has magnificent advantage over EKF and IAE in regard to stability and accuracy when the power level of measurements interference is relatively high.