Identification and classification of selected internal combustion engine inefficiency based on vehicle structure vibrations

The combustion engine generates forced vibrations, caused by periodically acting external forces resulting from the combustion of the fuel-air mixture. Any changes in this process cause an increase in the value of vibration amplitude and a change in the distribution of harmonics dominating in the frequency domain. In order to identify selected malfunctions of the internal combustion engine of the Polaris off-road vehicle tested, its current parameters were correlated with the vibrations transmitted to the vehicle's structural elements. An integrated sensor for measuring acceleration using the direct method, made in MEMS technology, was used for the tests. The recorded signals of the acceleration components were subjected to analysis in the frequency domain, thus identifying the characteristic harmonic components in the analyzed spectrum. For the classification of incompleteness based on registered signals, a diagnostic inference matrix based on our own algorithm of conduct was used.