DIAGNOSIS OF ENGINE ANOMALY UTILIZING THE STATISTICAL CHARACTERISTIC OF ENVELOPE WAVE-FORM FOR VIBRATION ON IGNITION

摘要

PURPOSE:To correctly detect and diagnose the anomaly of an engine by extracting the envelope wave-form of the vibration signal on engine ignition and calculating a plurality of statistical characteristic values from the wave form, and collating said value with the prescribed operation-state discriminating patterns. CONSTITUTION:The output signal of a vibration detecting means 1 for detecting the vibration on engine ignition at each certain time is sent into an envelope extracting means 2, and the wave form of the envelope is extracted from the input form. The extracted wave form T of the envelope is numeric-value-converted by an AD converter 3, and input into an extracting means 4 for the envelope wave-form characteristic, and the actual effectiveness, strain degree, and peak degree are calculated, and the exponential smoothing average value is calculated. The asymmetric area and the exponential smoothing average value of the mutual correlation function are calculated from the wave form T and the reference wave form in a variety of anomaly by an envelope symmetrical-degree detecting means 5. The output signals of the both detecting means 4 and 5 are compared in an operation-state judging means 6 to detect and diagnose anomaly.