An Optimized Method for Fault Propagation Analysis of Mechatronic Systems

This paper proposes a new optimized method for fault propagation analysis (FPA) of mechatronic systems. In order to analyze the fault propagation to locate the most vulnerable point, the relevant components of this type of system, such as the software, are abstracted into corresponding models. Firstly, we use a novel graphical representation of a module-signal diagram (MSD) transformed to a signal fault propagation tree (SFPT) and a module fault propagation tree (MFPT). Then fault propagation characteristic parameters are defined to calculate the index of vulnerability for the modules. Meanwhile, a method is presented to find out the most vulnerable path. Finally, a case study of a four-rotor unmanned helicopter is provided to demonstrate and validate the proposed method. By injecting fault to attitude adjustment software modules, we can obtain the fault propagation probability of all modules and the data transfer probability from a module to signals. Then the corresponding SFPT and MFPT can be built from the MSD of the attitude adjustment software system. The final result is the most vulnerable module and path of the example system after performing the proposed method of fault propagation analysis. The result can be used for predicting to locate the fault of mechatronic software systems.