Misfire and compression fault detection through the energy model

This article proposes a simple algorithm for misfire detection in reciprocating engines. The algorithm, based on an energy model of the engine, requires the measurement of the instantaneous angular speed. By processing the engine dynamics in the angular domain, variations in the working parameters of the engine, such as external load and mean angular speed, are compensated. A dimensionless feature has been abstracted for evaluation of the combustion as well as compression process of each cylinder. The proposed technique is expected to be easy to implement and to provide useful information for on-line monitoring of the in-cylinder processes in an internal combustion engine.