Test Analysis And Research On Sound Quality Of Electric Vehicle

The research on the noise of vehicle is a key point in vehicle NVH. At present, the majority of domestic and foreign noise standards or criteria are based on the A-weighted sound pressure level (SPL). The SPL of electric vehicle interior noise is much smaller than the traditional internal combustion engine vehicle noise, the traditional method in SPL as the evaluation standard is no longer adapted for electric vehicle research, using sound quality which based on subjective evaluation provide a new way on the study of analyzing the electric vehicle noise.In this thesis, the noise quality of electric vehicles is evaluated by calculating the objective parameters and subjective evaluation test. The subjective evaluation model is built up, which offer a certain guidance to evaluate the sound quality.This thesis investigates the human auditory characteristics and introduces the algorithm of loudness, sharpness, roughness and fluctuation. Based on the Zwicker loudness, the programs of the parameters above are realized by matlab program and the accuracy of the calculation is verified.By testing the electric vehicle under the typical operating conditions, vehicle inner noise signal are obtained, and the objective parameters are calculated and the inner noise are compared and evaluated. Samples are collected from the inner noise signals, and the samples are made a subjective test (jury test) to evaluate the subjective scores. Comparisons and evaluations are made again by the scores.Through multiple regression analysis, a multivariate regression model â…  is built, by converting objective parameters, then model â…¡ and model â…¢ are obtained, the model through the significant test. By comparison, we find, model â…¢ is more precise, thus a more feasible improved method is obtained.