Search Results

Fluctuation in the sound pressure level of the interior noise of an on-road vehicle is always caused by unpredictable factors such as wind gusts, traffic, roadside obstacles, and changing drive-by-drive conditions, and is hence, not reproducible in nature. Since the human brain is known to be more sensitive to noise that is amplitude-modulated than noise at a steady level [1], it is important to evaluate and improve the NVH performance of a vehicle in terms of the fluctuating interior noise likely to be experienced by drivers or users. To this end, an evaluation system was developed as part of this study, the details of which are presented in this paper. The system is composed of hardware for database storage and replay of sounds, and software for synthesizing the noise signals. For given wind tunnel test results, the evaluation system yields a wind noise model that can synthesize wind noise signals for any wind scenario.

In the new product development of vehicle suspension system, the spindle or component loads are very important for optimization of component design for weight and fatigue life. Accurate loads of spindle force at the early stage of vehicle development will help to reduce the number of design changes and there by shortening of the product development cost and time. This paper introduces a reliable method to calculate spindle force. This method requires two models that are tire and road profile. However, precise modeling of tire is not easy because of nonlinear effects between tire and ground. Therefore, new method is proposed which makes the response of the spindle force with a linear tire model be the same as the test result. Virtual road profile is made by using equivalent damage method which is based on frequency response function between road and wheel. This road profile contains the ground characteristics and nonlinear effects between road and wheel.