Detection and Correction of injection failures in diesel engines on the basis of turbocharger instantaneous speed frequency analysis

Combustion failure diagnosis techniques for reciprocating internal combustion engines have been developed over the last few years. Nowadays the most usual techniques are based on the crankshaft instantaneous speed or on engine vibrations. These methods, although successfully in use, may be applied only to maintenance tasks or to low and moderate engine speeds. In this paper, a controller for the correction of injection failures is presented. The aim of the algorithm is to ensure that the same quantity of fuel is injected into each one of the cylinders. This governor can be applied to the full operating range of the engine. The injection failure detection and identification technique is based on the measurement of the turbocharger instantaneous speed and its treatment in the frequency domain. The simulation of the controller shows an effective reduction in the dispersion between cylinders to a level below 2 per cent.