发动机块振动测量毕业设计外文文献翻译.rar

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《对于发动机块振动测量中多个激力事件的鉴别而做的单点时频分析》

作者：威廉，邓恩，波特查，理查森和金
英国布赖顿的苏塞克斯大学工程设计部
地址：捷豹汽车有限公司动力传动工程，工程中心，修道院路，惠特利，考文垂CV3 4LF ，英国。


摘要
通过从振动传感器采集来的单点加速度数据采用短时傅立叶变换（简称STFT）可以用来识别发电机组的不同振源。研究的重点是利用短期傅里叶变换区分正常燃烧和异常燃烧，途径是通过从其他来源的激励包括阀影响，喷油器脉冲，爆震等等来区分。使用单一的方法来检测另一种活动可用于前处理的衡量爆震传感器数据基于神经网络的重建气缸压力。这对于分离各种爆振声系统中的某些部分也是有用的。通过一系列试验数据孤立这些不同活动的3缸汽油发动机。在每种情况中，测量数据处理采用短时傅里叶变换，以企图孤立发生的特定事件的时域。有四组实验要开始： （一）没有点燃的（马达）发动机，用测力计测驱动力，发动机安装了火花塞，然后移开，隔离阀的影响; （二）点燃的发动机在自由状况下运行，然后来比较空载燃烧和没有燃烧; （三）加部分载荷的引擎正常运行，然后运行一个喷油器开关的关闭， （四）让满载的发动机正常运行，然后关闭爆震控制。该研究表明，通过短时傅里叶变换一个单一的时频分析方法，如果适当的调整分离和使用爆震传感器数据，可以有效地确定发生这些事件的反应时域。


文章概要
1 、导言
2 、利用短时傅里叶变换进行时频分析
3 、发动机试验方案和实验数据采集
3.1 、实验测试方案
3.2 、数据采集
参考资料


Time-frequency analysis of single-point engine-block vibration measurements for multiple excitation-event identification
S. Vulli, J.F. Dunne,,, R. Potenza, D. Richardson and P. King
Department of Engineering and Design, The University of Sussex, Falmer, Brighton BN1 9QT, UK
Advanced Powertrain Engineering, Jaguar Cars Limited, Engineering Centre, Abbey Road, Whitley, Coventry CV3 4LF, UK



Abstract
The short-term-Fourier-transform (STFT) is used to identify different sources of IC engine-block vibration from single-point acceleration measurements taken with a commercial knock sensor. Interest is focused on using the STFT to distinguish normal combustion from other sources of excitation including valve impact, injector pulses, and abnormal combustion, such as knocking. Positive identification of these other events using a single method can be useful for pre-processing of measured knock-sensor data for neural-network-based reconstruction of cylinder pressure. It can also be useful separately as part of a fast knock detection system. A series of experiments is discussed to create the data to isolate these different events on a 3-cylinder gasoline engine. In each case, the measured data is processed using the STFT to attempt to isolate the occurrence of particular events in the time domain. Four classes of experiments are undertaken: (i) an un-fired (motored) engine, driven by a dynamometer, with spark plugs fitted, and then removed, to isolate valve impact; (ii) a fired engine running under idle conditions, to contrast no-load combustion with no combustion; (iii) a part-loaded engine running normally, and then running with one injector switched-off, and (iv) a fully-loaded engine running normally, and then running with knock-control switched-off. The paper shows that a single Time-frequency analysis method, applied to knock sensor data in the form of an appropriately-tuned STFT, can effectively identify the occurrence of these events in the time domain if responses are adequately separated and strong enough.
Article Outline
1. Introduction
2. Time-frequency analysis using the STFT
3. Engine test programme and experimental data acquisition
3.1. Experimental test programme
3.2. Data acquisition
Acknowledgements
References