Research On Active Noise Control System Of Driver’s Earside Noise Based On DSP

Along with the development of vehicle industry,the public demands on the vehicle comfort is increasing.The interior noise level of vehicle is not only one of the most intuitive feelings of drivers and passengers,but also a key factor affecting the comfort of the whole automobile,which has a great effect on consumer purchase intention.Therefore,the research of vehicle interior noise control is always one of the focus of manufacturers.Passive noise control has limitations on low frequency noise control.In this case,active noise control has become a research hotspot,which has advantages such as small equipment volume and good noise elimination performance on low frequency.In this paper,the research focuses on active noise control for driving position area in the car.Firstly,the principle and type of active noise control are explained.The vehicle interior noise in the car is tested according to the test standards,and its frequency distribution is obtained.Then the theoretical derivation of Fx LMS algorithms is carried out,and the performance of algorithm is analyzed by simulate convergence speed and steady state error with difference filter length and convergent coefficient.Based on those efforts presented above,an improved variable-step-size LMS algorithm with a relatively small calculation is proposed.Simulation experiments on MATLAB verify this algorithm can improve the contradiction between convergence speed and steady state error.Finally,hardware and electro-acoustic equipment are selected for active noise control system,the second path transfer function identification module and noise control module are designed by using the variable-step-size LMS algorithm,and the active noise control hardware system is built based on DSP.The real vehicle test shows that the active noise control system designed in this paper can attenuate the noise at the right ear of the driver’s seat.