A Study on the Knocking and Misfire Detection System Using Breakdown Voltage Characteristics

Engine knocking and misfire cause a negative effect on the engine power and the exhaust emissions such as HC, CO and NOx. They also cause permanent damages to the three way catalyst (TWC) system. And a heavy knock can cause severe damages to the engine itself, which gives more reason why it must be detected and corrected. This study introduces a new system concept for detecting combustion misfire and knocking using breakdown voltage (BDV) characteristics between spark plug electrodes. This system detects and evaluates the degree of combustion by measuring the breakdown voltage which predicts that the breakdown voltage depends on the pressure and the temperature.