Fault Diagnosis Study of Complex Mechanism Based on FMA Function Decomposition Model

In the study of Reliability Technology, failures reflect in the inability to perform of basic parts. In order to seek the fundamental causes, FMA (function-motion-action) function decomposition model was utilized. By the decomposition stepwise, all basic actions formed the complex mechanism functions were found out, which were called Action. The failure model of action units was built by the fuzzy control theory. The key actions were worked out and the improved design measures were put forward, which proves the method valid.