Abstract
This thesis is motivated by the increasing use of electrified bicycles and the associated noise emissions. The objective of the work is to investigate the effects of selected modifications in the transmission on airborne and structure-borne noise emissions. For this purpose, structure-borne noise measurements are performed using accelerometers, and airborne noise measurements are conducted with an acoustic camera. By comparing the measurement results, potential applications of the acoustic camera in the field of NVH analysis (Noise, Vibration, Harshness) are evaluated.After a theoretical examination of sound propagation and relevant sound sources, appropriate measurement techniques and efficient methods for signal processing are selected. Subsequently, a test bench for measuring noise emissions is set up. Following validation of the recorded data to ensure the suitability of the chosen signal processing method, various modifications of transmission components are examined under different load scenarios.
The evaluation of the collected data allows for a comparison of the two measurement methods, revealing that the use of a special lubricant leads to noise reduction in both methods. Based on insights from the signal processing, a limited application of the acoustic camera for NVH analysis is inferred.
The summary of this work highlights the impact of the components examined and suggests possible approaches for future improvements in measurements.
Date of Award | Oct 2024 |
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Original language | German (Austria) |
Supervisor | Gerald Zauner (Supervisor) |