基于波束形成的汽车前围板隔声测量方法  

Transmission loss measurement method for car dash panel based on beamforming

作　　者：杨洋[1] 褚志刚[2] 沈林邦 周亚男[2] 段云炀 

机构地区：[1]重庆工业职业技术学院车辆工程学院,重庆401120 [2]重庆大学机械工程学院,重庆400044

出　　处：《农业工程学报》2014年第5期42-49,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(50975296);中央高校基本科研业务费资助项目(CDJZR13110001)

摘　　要：为提高隔声量测量效率，提出了基于波束形成的测量方法，与传统混响室-消声室声强测量法对某汽车前围板隔声量的测量结果的对比表明：该方法可以准确识别被测试件的隔声薄弱部位，可以准确计算2000 Hz以下频段被测试件的隔声量，2000 Hz以上频段虽然其计算的隔声量偏低，但可用于分析不同条件的隔声量的差异或评判隔声量的改进效果；空调进气口内外循环转换阀与阀口贴合不紧密是主要的隔声薄弱环节。在此基础上，对空调进气口内外循环转换阀和前围板声学材料进行改进，测量结果表明：改进后，该汽车前围板的隔声量在500～5000 Hz频段平均提高了约4.2 dB，对改善其隔声性能进而改善车内声学环境具有重要意义。Conventional methods for transmission loss measurement have drawbacks such as failing to identify poor sound insulation positions or time-consuming. In order to overcome these shortages, an innovative method was proposed, which is based on beamforming noise source identification technology and estimation of partial area sound power with beamforming scaled sound intensity. Its effectiveness was validated by comparing the transmission loss of a car dash panel before and after parts of dash panel were installed using the proposed method and the conventional sound intensity method. The experiment was conducted in a specialized laboratory consisting of a reverberation room and an anechoic room. In the reverberation room, an omnidirectional sound source （Br＆#252;el＆amp;Kj？r Type 4292） was excited by white noise emitted from PULSE front end and was amplified by a power amplifier （Br＆#252;el＆amp;Kj？r Type 2716）, and a microphone （Br＆#252;el＆amp;Kj？r Type 4187） was utilized to measure sound pressure signals. In the anechoic room, different instruments were used for sound signal collection. For the test with the conventional method, a dual-microphone sound intensity probe （Br＆#252;el＆amp;Kj？r Type 3599） was used to scan and measure sound intensity from the surface of the car dash panel, while for the test with the beamforming method, a 36-channel sector wheel array with a diameter of 0.65 m （Br＆#252;el＆amp;Kj？r） was utilized to collect sound pressure signals. After signal processing based on the principles of the two methods, contour maps and transmission loss curves of the car dash panel were drawn. Results showed that compared with the conventional method, the proposed method could not only accurately locate the position where sound insulation was poor in the dash panel, but also evaluate the transmission loss of the dash panel at frequencies up to 2 000 Hz. Although the proposed method underestimated the transmission loss at frequencies more than 2 000 Hz because of infl

关 键 词：波束形成 测量 车辆 隔声量 声强 改进 

分 类 号：TB52[理学—物理] U467.3[理学—声学]