Gearbox Rattle Characterisation Using Low-Cost Measurements and Limited On-Road Data

The present thesis work concerns a data analysis in both the time domain and the frequency domain, to assess the presence and the severity of the rattle phenomenon in the gearbox under test. The objective is to develop a structured inspection methodology for the issue, potentially identifying some thresholds to determine more objectively whether a generic gearbox is affected by the rattle issue under some specific conditions. Specifically, the present work aims at validating three rattle indicators using a limited dataset that was collected by CNH Industrial during various tests and that was shared with the University of Ferrara. This dataset consists of five cases of acoustic pressure recorded with microphones, together with the rotational speed of some shafts and gears. These measurements can be very easily acquired, and most importantly, with a non-intrusive approach, meaning that the rattle phenomenon can be studied directly with the vehicle on road.