Research on fuzzy diagnosis Expert System of electronic control engine

According to the character of the Electronic control engine, Diagnosis Expert System of Electronic control engine was developed based on commix fuzzy reasoning. The system includes Knowledge base, Reasoning machine, Explain system, management system. Considering about fuzzy relation between fault cause and symptom, commix fuzzy reasoning diagnosis method was set up by means of fuzzy synthesize judge. Knowledge of expert was expressed as three parts: Fault Symptom, System´s Fault and Part´s Fault. On-Board-Diagnosis method and general measure instruments method worked together in the system, and by utilizing commix fuzzy reasoning method, complex fault´s diagnosis become efficient. By using Diagnosis Tree method, the causes of faults can be found in best way, with high distinguishing rate, low error diagnosis rate and least cost. By means of Waveform Analysis diagnosis method, abundant information about fault can be acquired accurately as waveform by measuring. And by basic character of waveform´s main observation point, cause of a fault and Certainty Factor can be achieved. By utilizing commix fuzzy reasoning diagnosis method and Diagnosis Tree method and Waveform Analysis diagnosis method, fault orientation became more convenience.