基于虚拟仪器的发动机噪声测试与分析系统开发

发布时间：2018-04-23 19:08

本文选题：发动机 + 噪声测试　；参考：《昆明理工大学》2016年硕士论文

【摘要】：发动机向着轻量化、高速化与集成化的方向发展,为发动机噪声控制提出了更加严峻的挑战。发动机向周围辐射噪声影响人们的正常休息和睡眠,影响工作效率,高分贝的噪声损坏人们的听觉器官,长期处于高强度噪声中,将出现头晕、头痛等生理影响。因此,对发动机进行噪声控制非常重要。然而,在对内燃机进行噪声控制之前,必需对内燃机的主要噪声源进行分离识别并对其噪声信号的时频特性进行研究,为此,针对发动机噪声测试与分析开发一套集测试与分析于一体的系统非常有必要。针对发动机噪声测试与分析系统研究的内容,系统分析了国内外噪声测试技术的发展趋势,从噪声测试与分析技术入手,深入分析和推导了小波分析、近场声全息技术、偏相干算法等。结合虚拟仪器技术,将测试与分析系统分成硬件和软件结构进行深入研究。硬件方面,设计了一自动移动控制线阵列装置,与传声器、PXI4498数据采集卡等组建系统的硬件结构；软件方面,通过虚拟仪器开发平台编制了时频域分析、基于空间FFT变换的声全息技术和偏相干算法等,搭建了集时频域分析、近场声全息技术和9点声功率级测试于一体的测试平台。为了验证发动机噪声测试与分析系统的实用性和有效性,在普通台架上对云内YN38CRD2型柴油机1600 r·min-1和1800 r·min-170 N·M两个工况下进行了近场声全息测试。通过测试与分析系统的时频域模块对噪声信号进行了频谱分析连续小波分析等。分析结果表明：1600 r·min-1工况下,发动机噪声的主要能量分布在0～220Hz,300～850Hz,1000～1150Hz,1150～1600Hz,1900～2110Hz,2200～2600Hz范围内,1800rmin-170NM工况下,发动机噪声的主要能量分布在0-250Hz, 400～700Hz,700～2000Hz,2000～2600Hz,并对这些优势频带在重建面上的声压级进行了重建。重建结果验证了发动机噪声测试与分析系统中声全息技术能够有效的分离主要声源。同时,依据《GB/T 1859往复式内燃机辐射的空气噪声测量工程法及简易法》在半消声室内对4100QB型柴油机怠速工况下进行了9点声功率级测试,试验验证了系统可以满足企业的工程实用。
[Abstract]:The development of engine towards the direction of lightweight, high speed and integration presents a more severe challenge for engine noise control. The radiated noise from the engine affects the normal rest and sleep of people and affects the working efficiency. The high decibel noise damages the hearing organ of the people and is in the high intensity noise for a long time it will have physiological effects such as dizziness headache and so on. Therefore, it is very important to control the engine noise. However, before the internal combustion engine is controlled by noise, it is necessary to separate and identify the main noise sources of the internal combustion engine and study the time-frequency characteristics of its noise signals. It is necessary to develop a set of test and analysis system for engine noise test and analysis. In view of the research content of engine noise test and analysis system, the development trend of noise measurement technology at home and abroad is analyzed systematically. The wavelet analysis and near-field acoustic holography technology are deeply analyzed and deduced from the noise measurement and analysis technology. Partial coherence algorithm and so on. Combined with virtual instrument technology, the test and analysis system is divided into hardware and software structure. In terms of hardware, an automatic mobile control line array device is designed, and the hardware structure of the system is constructed with a microphone PXI4498 data acquisition card. In software, time-frequency analysis is compiled through a virtual instrument development platform. Based on the acoustic holography technology and partial coherence algorithm of spatial FFT transform, a testing platform is built which integrates time-frequency analysis, near-field acoustic holography and 9-point acoustic power level measurement. In order to verify the practicability and effectiveness of the engine noise measurement and analysis system, the near-field acoustic holography tests were carried out under two operating conditions of 1600 r min-1 and 1800 r min-170 N M of the YN38CRD2 diesel engine in the cloud on the ordinary bench. The time and frequency domain module of the system is used to analyze the frequency spectrum of the noise signal by continuous wavelet analysis and so on. The results show that the main energy distribution of engine noise is in the range of 1800rmin-170NM under the operating conditions of 1: 1600r min-1, and the main energy distribution of engine noise is in the range of 0 ~ 220Hz, 400Hz ~ 700Hz ~ 2000Hz, and the sound pressure levels of these dominant frequency bands on the reconstructed plane are reconstructed. The main energy distribution of engine noise is in the range of 0 ~ 250 Hz, 400 Hz ~ 700 Hz ~ 2 000 Hz ~ 2 000 Hz ~ 2 600 Hz, and the sound pressure level of these dominant frequency bands is reconstructed on the reconstructed plane. The main energy distribution of engine noise is in the range of 0 ~ 250 Hz, 400 Hz, 700 Hz ~ 2 000 Hz ~ 2 000 Hz, and the sound pressure level of these superior frequency bands is reconstructed in the reconstructed plane. The reconstruction results show that the acoustic holography can effectively separate the main sound sources in the engine noise measurement and analysis system. At the same time, according to the engineering method and simple method of measuring the air noise of GB/T 1859 reciprocating internal combustion engine radiation, the 9 point sound power level of 4100QB diesel engine under idle condition is measured in the semi noise control chamber. The experimental results show that the system can meet the engineering needs of enterprises.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK406

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