Parameter-Independent Event-Triggered Implicit UKF for the Celestial Navigation Using Time Delay Measurement

Celestial navigation using time delay measurement is an innovative autonomous method. To calculate the equivalent measurement, numerical method needs to be applied, which time-consuming. The event-triggered mechanism intermittently and aperiodically processes measurements by judging if update error has changed drastically. However, its performance greatly affected constant threshold. solve this problem, a parameter-independent implicit unscented Kalman filter (UKF) proposed applied celestial measurement. innovation at current moment updated estimate covariance last are compared with previous value instead of event automatically triggered when accuracy state low. Simulation results indicate that UKF can reduce running reducing unnecessary updates, whose will not any parameter or window size. In word, substitutes dynamic threshold for threshold, ensuring