Comparison of vibroacoustic signals generated by combustion engine acquired with accelerometer and microphone
Mechanical vibrations generated by a working combustion engine are widely used as a source of information used both, to assess the current state of the internal combustion process as well to assess the technical health condition of cooperating subassemblies. In the classic approach, acceleration sensors mounted directly on structural elements are most often used. The parameters of the acquired signal depend naturally on the characteristics of the sensor and its location in relation to the source of vibrations, and are related to the nature of its propagation in specific medium. In an alternative approach, the source of information used in the analysis of vibroacoustic signals is sound yield from microphone devices. The propagation of the signal in two consecutive mediums - body structure and air, affects the final content of its vibroacoustic spectrum. The effect of modifying the vibroacoustic signal at the stage of propagation in the air can have a positive or negative impact on the final result in accordance with assumed research goal. In the presentation, preliminary results of measurements of signals recorded from selected engines with the use of both accelerometers and microphone devices are presented.
Topic: Engine testing and modeling
Author: Michał Śmieja
Co-authors: Kamil Duda, Jakub Banach
