Demanding legislation on exhaust emissions and fuel consumption has led great attention to on board control algorithms able to optimize the combustion process in terms of efficiency and pollutants emissions production.
Dealing with turbocharged engines, the thermo and fluid dynamic conditions of the exhaust gas are responsible for the turbine rotation; its speed has demonstrated to be related to the combustion process and can be used for the combustion monitoring.
This work presents a methodology in which the instantaneous turbocharger speed is obtained by the processing of the signal from an accelerometer mounted on the compressor housing.
Experimental tests have been carried out on a small water-cooled, two cylinder, common rail diesel engine installed in the Laboratory of the Engineering Department at ‘ROMA TRE’ University. The methodology has been applied to the signals acquired during steady state and transient tests. The comparison between the estimations provided by the accelerometer and the values obtained by direct measurements highlighted the accuracy of the predictions thus demonstrating the suitability of the accelerometer to be used as feedback signal in algorithms for the engine management in order to maintain the combustion effectiveness in spite of aging and degradation of components, variations of fuel properties.