A research on fault diagnostic expert system based on fuzzy Petri nets for FMS machining cell

In view of the fuzziness and the uncertainty of expert knowledge in fault diagnosis expert system for the flexible manufacturing cell (FMC), this paper presents fuzzy production rule (FPR) knowledge representation and storage using fuzzy Petri nets (FPN) model, and their reasoning mechanism and algorithm implementation. Based on these, taking the FFS-1500-2 FMC as an object, by acquiring the PLC data online, analyzing the logic relations of each signal of PLC ladder-shaped graph and the hardware of FMC in detail, and especially combining the information of a multisensor condition monitoring and synthetic decision system, expert and user experience knowledge, a fault diagnostic expert system has been built up. A detailed reasoning illustration about the spindle servo fault is presented that has proved the feasibility and the validity of the FPN diagnosis system.