【作者】 马飞；

【导师】 陈华新；

【作者基本信息】 武汉理工大学 ， 动力机械及工程， 2003， 硕士

【摘要】 本文较详细的叙述了利用虚拟仪器技术(Virtual Instrument，简称VI)构建针对汽车或摩托车发动机的噪声测试系统。 本文首先分析了发动机噪声的组成和产生机理；发动机的噪声可分为表面噪声和直接向大气辐射噪声，表面噪声又可分为机械噪声和燃烧噪声。本文指出发动机噪声与发动机转速的直接关系，并且着眼于从发动机整体噪声测试入手，找到发动机噪声源。 其次本文提出将虚拟仪器技术引入了发动机噪声测试，先后设计和选择了测试系统的硬件部分，软件部分。在硬件设计方面，先是选用Microphone作为传声器、完成设计了信号放大电路、选择了合适的数据采集卡，然后是提出利用个人计算机自带的声卡作为简单数据采集卡。在软件设计方面，提出了使用被CAT(计算机辅助测试技术)领域广泛采用的美国NI公司的LabVIEW作为本测试系统软件部分的开发程序，并且编写了一组程序完成测试的控制、信号的滤波、信号的频谱变换以及屏幕显示面板。 最后本文通过采用本测试系统和Spectralab针对某型号发电机用发动机试验，测试了发动机在零负荷和外带400W负荷下的发动机噪声，进行了频谱分析。证明本测试系统能够满足噪声测试及频谱分析的需求，为在发动机测试领域里采用先进的虚拟仪器测试技术提供了理论和实践依据。更多还原

【Abstract】 This thesis discusses detail about how to research a noise testing system for automobile engine based on virtual instrument (shortly: VI).Firstly this paper analyses what the automobile engine noise make and how the noise work. The noise of engine includes the noise of surface and the noise of eradiating to atmosphere directly. And the noise of surface make of mechanical noise and the noise of combustion. And the thesis discusses how to test the whole noise of engine and how to find good ways to control the noise of engine.Secondly this paper gives a way to use the VI to finish the testing work. And the paper discusses how to research the hardware and software of this engine noise testing VI. About the hardware, the paper advises using microphone as sound sensor, researches signal magnify circuit and chooses the feat DAQ Card: bring forward that using the Sound Card as simply DAQ Card. About the software, this paper suggests that using LabVIEW, which is used broadly in CAT field by the American Company-NI, as the basic software program.At last, this paper records the test about the noise of some generator engine under zero’ s or 400W s load via the VI and the Spectralab software. The test process proves that this noise testing Virtual Instrument can fit for testing the noise of automobile engine and for analyzing what engine’ s noise include. In the end, this thesis lodges a new concept by researching VI to testing other function of engine not only it’ s noise.更多还原