Study on the order target of the sporty sound quality of the vehicle exhaust noise under acceleration

Abstract

Correlational studies of order noise sample tuning and subjective evaluation test of sound quality were conducted to achieve sporty sound quality and confirm the correlation between the auditory sense (subjective) and the order noise level (objective) of vehicle exhaust noise under acceleration. First, the frequency range and the order ingredient of sporty quality noise were confirmed by a study of ear-hearing subjective feeling on the basis of physiological acoustics. By using an order tuning software that was developed independently, the second, fourth, and sixth order noise A-weighting sound pressure level (dB(A)) of the exhaust noise of an objective vehicle were tuned segmentally into numerous sound samples. Furthermore, samples with high sporty sound quality were selected through subjective evaluation, and the A-weighting sound pressure level (dB(A)) distributions of the second, fourth, and sixth order noise of these samples were analyzed. Consequently, the relative size relations of the second, fourth, and sixth order noise of all the exhaust noise with sporty sound quality were determined. In addition, the curve distribution zones of the corresponding order noise were formed and the order quantitative target of the sporty sound quality was considered. Finally, four passenger vehicles with representative sound qualities (sporty, quiet, and characterless) on the market were selected as the benchmark vehicles; their order noise was objectively tested and their sound qualities subjectively evaluated. Meanwhile, the order noise objective test result was compared with the order target. Results showed that when the fourth and sixth order noise curves relative to the second order noise curves were within the order target zones at most of the engine speeds, the exhaust noise of the vehicle had considerable sporty sound quality; otherwise, it did not have such a sound. Therefore, the order target of the sporty sound quality was accurate and effective.

Research on noise control of automobile exhaust system under idling condition based on modal analysis

“…According to the classical definition of modal analysis, modal analysis is an analysis process based on the vibration of a linear system and aimed at obtaining modal parameters of the system. 6 The main purposes of modal analysis are as follows: (1) To understand the resonance region of the structure, determine the modal parameters, such as natural frequency, damping, mode shape, etc., and provide guidance for the structure design; (2) To verify the accuracy of the numerical calculation model; (3) To be the basis of transient analysis and spectrum analysis.…”

“…1 Therefore, to study and optimize the vibration characteristics of exhaust system is not only beneficial to improve its own vibration and noise level and improve its service life, but also plays a very important role in improving the vehicle NVH level. 2,3…”

“…1 Therefore, to study and optimize the vibration characteristics of exhaust system is not only beneficial to improve its own vibration and noise level and improve its service life, but also plays a very important role in improving the vehicle NVH level. 2,3 Research has shown that vehicles generally have the phenomenon of body vibration and oversized exhaust noise under idling condition, which is probably related to the resonance between the exhaust system and vibration excitation of the engine. Therefore, the structural performance analysis and resonance decoupling of the exhaust system can effectively solve the problem of body vibration and oversized exhaust noise under idling condition.…”

Toward a cylinder pressure signals-based active synthesis algorithm for engine sound

“…On the whole, the recorded engine sound is powerful and strong, the order sounds are clear, harmonious, and coherent, which satisfies people's subjective feeling for a powerful engine sound. 30 The recorded engine cylinder pressure signal is showed in Figure 7(c), note that the time period for demonstration is 74.45-76.00 s, which corresponds to a low engine speed (approximately 2200 RPM) and a low load. As described in Section ''Construction of the index matrix,'' the periodic changes are presented in the cylinder pressure signal curve, and two adjacent peaks represent a complete engine cycle.…”

A Study on Affective Dimensions to Engine Acceleration Sound Quality Using Acoustic Parameters

“…People evaluate vehicles based on a variety of design factors such as the overall appearance of the vehicle or the sound of the engine [1,2]. In response to consumers' tendency to be satisfied when they come across products that exceed their expectations with superior features, many companies in the automotive industry have focused on developing design elements that satisfy the human senses [3,4].…”