Prediction And Analysis Technique Of Sound Quality For Heavy Commercial Vehicle Cab

With the rapid development of urbanization and the rapid start of the logistics industry, heavy commercial vehicles have already become an important part of cargo transport. The acoustic comfort of heavy commercial vehicle has attracted more and more attention of consumers and the major automobile manufacturers. After many years of development and the joint efforts of researchers, the cab noise has been effectively controlled. The physical damage to the human ears has be en initially solved, but the psychological damage still exists. The focus of NVH has thus turned to sound quality optimization. How to get the sound quality technology effectively integrated into the traditiona l acoustic design has become an important research direction of the future NVH development.This paper proposed the virtual sound quality prediction method based on the hybrid FE-SEA, SEA analysis method, sound quality evaluation theory and sound quality objective parameters distribution principle. Us ing the idea of combining test with virtual simulation technology, we established a contact between the sound quality parameters and the cab structures. Through the virtual d istribution of objective psychoacoustic parameters, we can directly find out the great influence vehicle structure to the cab sound quality.Firstly, based on the BP neural network and the subjective and objective evaluation test data, a heavy commercial vehicle cab sound quality assessment and forecast model was established.Secondly, the SEA model and the hybrid FE-SEA model were established. Three major parameters were obtained through theoretical analysis and numerical calculation. The excitations of the models were measured by real vehicle road tests and the simulation tests. Tests were carried out on the cab interior acoustic materials to get the absorption and insulation performances of the cab materials. The parameters and excitations were involved to forecast the cab noise to verify the models’ validity.Finally, based on sound quality objective psychoacoustic parameters distribution principle, virtual sound quality objective parameters prediction model was established, which combines the SEA and the hybrid FE-SEA model, to calculate the sound pressure levels and psychoacoustic parameters. The main influence factors were found out through the virtual distribution. Using a combination of sound insulation and damping optimization method to improve the cab sound quality. The virtual improvement of sound quality was forecasted by the virtual sound quality prediction model, which is verified by real vehicle optimization.