Development of the knocking and the defective cylinder decision system of industrial CRDI diesel engine through the CKP sensor signal analysis

As an abnormal combustion caused by the compression and spontaneous ignition of unburned mixture during the latter process of combustion, if knocking occurs, it will result in loss of engine power as well as severe damage to the engine. Therefore, it is very significant to monitor knocking. Generally, a practical method of monitoring knocking is to use a knocking sensor. However, by this method it is not possible to distinguish between the engine's own vibrations and knocking if the vibrations match up with the range of the knocking sensor signal for the use of detection of knocking. Therefore, in this study, knocking was diagnosed by way of using the signals of crankshaft position (CKP) sensor which is basically installed in the engine, instead of using such a problematic knocking sensor.