Diagnosis of combustion engines by analysis of the crankshaft's rotational speed

: Quante, F.; Fehrenbach, H.

Abstract
Important faults of combustion engines can be diagnosed by analysis of the crankshaft's rotational speed. In this contribution, an improvement of this method by simple statistical is described, taking into account the cyclical dispersion of ignition engines. Using this evaluation method, small and timevariant faults can be detected and the faulted cylinder in multicylinder machines can be identified. First results of a simplified theoretical model are compared with measured waveforms. Thus a better physical understanding of the waveforms and further developments of diagnostic procedures are possible. (IITB)