外文翻译--制造分析进程数据使用快速标记技术(编辑修改稿)

外文翻译--制造分析进程数据使用快速标记技术(编辑修改稿)内容摘要：

s information is discovered regarding the causes of these deviations it is then possible to move from novelty detection to diagnosis, but the ability to identify previously unseen abnormalities is retained at all stages. 3 External References Acpanying documentation providing further information on the data sets is available in unnumbered documents. 4 Glossary AUT Aachen University of Technology GMM Gaussian Mixture Model MLP MultiLayer Perception OBS Oxford BioSignals Ltd. 5 Data Description The following sections give a brief overview of the data set obtained by visual inspection of the data. Data types The data provided were recorded over a number of tests. Each test consisted of a similar procedure, in which an automated drill unit moved towards a static metallic disk at a fixed velocity (“feed”), a hole was drilled in the disk at that same feedrate. The following data streams were recorded during each test, each sampled at a rate of 20 KHz: Ax – acceleration of the diskmounting unit in the xplane1 , Ay acceleration of the diskmounting unit in the yplane1 , Az acceleration of the diskmounting unit in the zplane1 , AERMS acoustic emission, 50400 KHz2, SPpower delivered to the drill spindle3. Tests considered in this investigation used three drillprices (of identical product specification) as shown in Table 1. Table 1Experiment Parameters by Test Drill Number Test Numbers Drill Rotation Rate Feed Rate 1 [12] 1700RPM 80 mm/min 2 [3127] 1700RPM 80 mm/min 3 [130194] 1700RPM 120mm/min Note that tests 16,54,128,129 were not provided, thus a series of 190 tests are analysed in this investigation. These 190 tests are labeled as shown in Table 2. Table 2 –Test indices used in this report against actual test numbers Test Indices Actual Test Number [115] [115] [1652] [1753] [53125] [55127] [126190] [130194] Prior Experiment Knowledge Normal Tests AUT indicated that tests [10110] could be considered “normal processes”. AE Sensor Placement AUT noted that the position of the acoustic emission sensor was altered prior to test 77, and was adjusted prior to subsequent tests. From inspection of AE data, it appears that AE measurements are consistent after test 84, and so: AE is assumed to be unusable for tests [176] –the sensor records only white noise。 AE is assumed to be usable, but possibly abnormal, for tests [7783] –the sensor position is being adjusted, resulting in extreme variation in measurements。 AE is assumed to be usable for tests [94190] –the sensor position is held constant during these tests. Thus, the range of tests assumed to be normal [10110] should be reduced to [84110] when AE is considered. Test Description Data recorded for during a typical test are shown in Figure 1. The duration of this test is approximately t=51 seconds. This section uses this test to illustrate a typical process, as described by AUT. Drill poweron and poweroff events may be seen at the start and end of the test as transient spikes in SP. The drill unit is then moved towards the static disk at the constant feed rata specified in Table 1, between t=12 and 27 seconds. This corresponds to approximately constant values of SP during that period, approximately zero AE, and very lowamplitude acceleration in x,y,and z planes. At t=27 seconds, the drill makes contact with the static disk and begins to drill into the metal. This corresponds to a stepchange in SP to a higher lever, staying approximately constant until t=38 seconds. During this time, AE increases significantly to a largely constant but nonzero value. The values Ax and Az increase throughout this drilling operation, while the value of Ay remains approximately zero (as it does throughout the test). At t=38 seconds, the tip of the drillbit passes through the rear face of the disk. The value of SP increases until t=44 seconds. During this period, AE reaches correspondingly high values, while Ax and Az decrease in amplitude. At t=44 seconds, the direction of the drill unit is reversed, and the drill is retracted from the metal disk. Until t=46 seconds, the value of SP and AE decrease rapidly. A transient is observed in Ax and Az at t =44 seconds, with vibration amplitude decreasing until t=46 seconds. At t=46 seconds, the drillbit has been pletely retracted from the metal disk, and the unit continues to be withdrawn at the feed rate until the end of the test. The value of SP decreases during this period(noting the poweroff transient at the very end of the test), while the values of all three acceleration channels and AE are approximately zero. 6 .Preprocessing Removal of Start/Stop Transients Assuming that normal and abnormal system behaviour will be evident from data acquired during the drilling process, prior to analysis, each test was shortened by retaining only data between the start and stop events, shown as transients in SP. For example, for the test shown in Figure 1, this corresponds to retaining the period [1350] seconds. Removal of Power Supply Signal The 50 Hz power supply appears with in each channel, and was removed prior to analysis by application of a bandstop filter with stopband [4951] Hz. Frequency Transformation Data for each test were divided into windows of 4096 points. A 4096point FFT for was performed using data within each window, for Ax,Ay and Az channels. This corresponds to approximately 5 FFTs per second of data， similar to the QUICK system used in aerospace analysis， shown to provide s。