Further Study of the Vehicle Rattle Noise with Consideration of the Impact Rates and Loudness

With the prevalent trend of the pure electric vehicle, vehicle interior noise has been reduced significantly. However, other noises become prominent in the cabin. Especially, the BSR noise generated by friction between parts and the clearance between components become the elements of complaints directly affect the quality of vehicles. Currently, the BSR noises are subjectively evaluated by experts, and the noise samples are simply labeled as ‘qualified’ or ‘unqualified’. Therefore, it is necessary to develop an evaluation model to assess the BSR noise objectively. In this paper, we study the vehicle rattle noise intensively. Several types of rattle noise were recorded in a semi-anechoic room. The recorded signals were then processed in the LMS test lab. to extract the single impact segments. A pool of simulated signals with different impact rates (number of impacts per second) and various loudness was synthesized for analyzation. To verify the universality of the assessment, the in-vehicle background noises were also recorded. The in-vehicle background noises were added to the rattle noise samples to simulate the in-vehicle test environment. Sound metrics were calculated and compared for all the processed samples. Jury assessment with 5 experts were performed to evaluate the rattle noise samples. The correlation between the subjective evaluation and the impact rates as well as sound metrics were studied. Consequently, an objective assessing model for vehicle rattle noise was developed based on the above analysis. This study can be used to assess the rattle noise effectively, and it has bright prospect and great value in engineering.