Algorithm of fault diagnosis for satellite network

Automated fault diagnosis becomes increasingly important to satellite work. In an early paper, we introduced system level diagnosis theory into satellite iietwork firstly and presented two-level-node graph, a novel modeling method,. Based on these work, a new test invalidation model under certain fault pattern is presented and a diagnosis algorithni is proposed in this paper. Diagnosis can be divided into two steps, local diagnosis and centralized diagnosis. The former is distributed, which can reduce the diagnosis delay by collecting test results in satellites parallelly. The latter is centralized, which can make use of the regularity of satellite network. The procedure of local diagnosis is described by activity cycle diagram. During diagnosing, little professional knowledge about satellite needs to be involved. An example illustrates the diagnosis algorithm and its effect.