False Alarm Reduction Method for Formation Flying Spacecraft FDI

Abstract

The main focus of this paper is to propose a method for reducing a false alarm of formation flying spacecraft. In this paper, we construct a federated UKF to estimate navigation information and use threshold method for spacecraft fault detection and isolation. Also, we apply an extended scalar adaptive filter for preventing the false alarm as a pre-filtering method. An extended scalar filter is an adequate filtering method for eliminating abnormal jumping signal by estimating three different kinds of variances continuously. The measurement noise variance is estimated by using an innovation method while, the velocity error and the acceleration error variance are estimated through a least square method. This filter operates as a pre-filter of the local filter in the federated UKF. When the sensor output exceeds threshold limit due to sudden noise, we eliminate abnormal measurements. Simulation results show that the extended scalar adaptive filter can eliminate sudden abnormal measurements. Thus, the extended scalar adaptive filter is an adequate algorithm for reducing the false alarm.