Research On Vehicle Active Sound Management System

The rapid development of automobile industry leads to the improvement of vehicle performance requirements,the automobile NVH problem has been paid much attention in the decade.At present,many countries have introduced the relevant technical standards,laws and regulations on the car to limit noise.For interior noise,there are only limits on the coach,and no limits on the passenger car.For outside noise,it is usually considered that the quieter is the better,so the relevant standards only provide the upper limits of the noise and no lower limit requirements.At present,with the emergence of new technologies on the vehicle,some new NVH problems appear.Many six or eight-cylinder engines are replaced by four-cylinder engines.Electric vehicles are usually motor-driven.All of them lead to small noise in the cab,people cannot hear the traditional internal combustion engine noise with a sense of power roar.In order to meet some people who like high power engine noise,a number of car sound enhancement devices have been developed.With the increasing dual pressure of resources and the environment,electric cars are vigorously promoted for their unique advantages.However,because the electric cars running sound is too small,it is very dangerous for people with vision or hearing problems and bicyclists on both sides of the road.In order to solve this problem,some new technologies and regulations came into being.In this paper,some deep researches were conducted and the concept of vehicle active sound management system was put forward.This vehicle active sound management system mainly achieves two functions: 1)according to the vehicle operating condition,the system automatically plays the sound of the traditional engine noise in the cab,in order to enhance driving experience;2)based on the vehicle condition and the external environment,the system plays warning sound out of the vehicle,aimed at reminding other road users,while requiring minimal pollution to the external environment.In this paper,the simulation of engine sound was studied firstly.Based on a method call Granular Synthesis,an improved method was proposed and analyzed,which was verified that the method could simulate the engine sound with variable operating conditions.Secondly,the warning sound and the control strategy were discussed based on the needs and some foreign laws and regulations.Thirdly,the strategy of hardware and software design of the vehicle active sound management system was proposed and implemented.Fourthly,combined with the specific hardware and software design,engine sound and warning sound sample libraries were produced.At last,the system was installed into the real car for debugging and testing.According to the principle that different modules are test respectively,combined with subjective and objective evaluation and related standards,the system was tested.