Contour of vibroacoustic map in diagnoses of engines failure

Almost all engine failures have an influence on engine's vibration, which is described in the article .Of course not every time diagnostic system can report of that. This is a reason why detection of vibrations must be accomplished with high quality diagnostic systems. Therefore, Doppler laser Vibrometry based on scanner Polytec had been used. To achieve full diagnostic results multidimensional vibration's function has been invented, where the torque moment is used as an extra parameter. Measured vibrations were subjected to digital signal processing like windowing, fast Fourier transform, filtration byfinite impulse response windowed filters. The results of measure and processing per-form inform of contour 3 D plots, which indulge in speed estimate of the usefulness of presented method. Tested engine performance, vibration measurement parameters, adopted diagnostic circuit, Digital processing of vibration signal, Vibration versus torque and magnitude spectrum (contour vibroacoustic map) of engine in good working order; co = 2000 rpm, contour vibroacoustic map of engine in good working order; co = 4000 rpm, contour vibroacoustic map of engine with fail of injection system; co = 2000 rpm, contour vibroacoustic map of engine with fail of injection system; co = 4000 rpm, contour vibroacoustic map of engine withfail of turbo charger; co = 2000 rpm are presented in the paper.