Study On Robustness Of Noise And Vibration Of Automobile

Automobile is becoming the major transportation of improving people’s trip, with the increasing number of vehicle, which have already resulted in the serious pollution of noise and vibration, and have caused many negative effects to the drivers and surroundings. Many automobile companies and scientific research institutions at home and abroad have invested huge human resources、financial resources and material resources on reducing the automobile vibration, to relieve the pollution of noise and vibration of automobile traffic, meet the demands and rules of limited noise, and improve the ride comfort. Based on the research status and deficiency of automobile noise、vibration、harshness, this paper put forward the study on robustness of noise and vibration of automobile, the main research and innovation are as follows:1) Based on the research status of automobile NVH and its robustness, this paper expounds the new field and development of automobile NVH, puts forward the research thought and content of this study.2) On the basis of the study of robust design technique and automobile development, this paper puts forward the concept of noise and vibration robustness of automobile development and using process; based on the design of experiment, this paper puts forward the robust analysis method of automobile noise and vibration. Based on the automobile life cycle theory and objective/subjective analysis method, the influencing factors of automobile noise and vibration of different ways and different stages are studied. The contribution degree concept of influencing factors, which cause the automobile noise and vibration of parts、system and complete vehicle to increase, is put forward. By example quantitative calculation 、 analysis and experiment, this paper studies the contribution rate of automobile noise and vibration of the engine surported parts change factors. The noise and vibration influence law of engine bracing piece is concluded, which can be reference for its optimization.3) On the basis of multi-objective restriction and sensitivity robust analysis method of automobile noise and vibration, study on simulation of noise and vibration of automobile typical system is studied by robust design technique. Factors of the four hanger of exhaust system and the damping and stiffness of front and rear suspension system, which have a different impact on automobile noise and vibration, is studied. By example calculation、analysis and experiment, it is concluded that the key robust evaluation index factor of the first vertical bending frequency of exhaust system noise and vibration is related hanger; and that the key robust evaluation index factors of suspension system noise and vibration are front suspension system damping and rear suspension stiffness.4) This paper develops suspension bench test system and substantial vehicle test of noise, by which experiments are done on the basis of simulation of robust analysis of automobile noise and vibration. The results of experiment show that damping and stiffness factors of simulation and bench test have the same influence on suspension system noise and vibration; by the simulation and experiment, the key factors of noise and vibration of exhaust system is the same result. It is showed that influencing factors robust analysis method of noise and vibration is efficient and effective.5) The article put forwards the robust basic principle of high mile automobile noise and vibration on the basis of research of automobile noise and vibration; the robust evaluation index system of high mile automobile noise and vibration is established based on acoustic theory、vibration theory、subjective grading、annoyance rate and psychoacoustics, the robust theoretic alanalysis model and evaluation process of high mile automobile noise and vibration are derived. Robust evaluation method of high mile automobile noise and vibration is put forward on the basis of statistics, and the application process of the method is explained by example, it is showed that the initial acoustic quality of automobile can not be used to embody characteristics of vibration and noise of high mile automobile, attenuation rate can be used to embody its acoustic quality.