美國(guó)PAC聲發(fā)射儀器

PAC公司多通道全數(shù)字化

聲發(fā)射檢測(cè)系統(tǒng)PAC數(shù)字化AE發(fā)展過(guò)程80’SLocan+TRA2.5ET，Turnkeysystem90’S初SPARTAN+TRA212

94年：第一代全數(shù)字化Mistras2001(AEDSP)99年底：第二代全數(shù)字化DiSP系統(tǒng)（4通道PCI總線）2001,DiSPVer5.0版(硬件X3，DMA）2002：PCI-8（SAMOS）2003：PCI-2

PAC公司數(shù)字化聲發(fā)射技術(shù)特征自90年代中期以AEDSP卡構(gòu)成的MISTRAS2001系統(tǒng)的成功問(wèn)世標(biāo)志PAC公司的AE技術(shù)進(jìn)入DSP數(shù)字化時(shí)代。PAC發(fā)展AE技術(shù)的綜旨：

高速、高效、實(shí)時(shí)、可靠

最大限度采用現(xiàn)代硬件技術(shù)

最大限度解決當(dāng)今AE問(wèn)題PAC公司技術(shù)特點(diǎn)：

DSP技術(shù)

并行DSP技術(shù)

并行處理

DISP的系統(tǒng)基于4通道AE卡——PCI/DSP-4

SAMOS系統(tǒng)的8通道AE卡——PCI-8PCI-8HFCard

8CompleteAEChannelsonasinglePCIcardUsesSMBConnectors3MS/sec,16bitA/D.2Parametricsperboard4High,4LowPassfilters1-400kHzbandwidth.MultipleFPGA’swithReal-TimeFeatureExtractionBuilt-inwaveformswithfixed4Ksamplelength(8kbytes)usingcircularbuffers.

2通道AE卡——PCI-2

系統(tǒng)主要技術(shù)特點(diǎn)全數(shù)字化計(jì)算機(jī)一體化CAT系統(tǒng)并行DSP處理系統(tǒng)高速DMA技術(shù)結(jié)構(gòu)化設(shè)計(jì)16位A/D（PCI-2為18位A/D）PCI總線AE特征參數(shù)/波形同時(shí)進(jìn)行16A/DPARAMETRICSAEINPUTS8ChannelParametrio&GroupController(In1stBoardOnly)DSP

Based4ChannelWaveformModuleOptionalDSP

BasedChannelControllerAndPCIBusInterfaceCircuitry28v

AST

28v

AST

28v

AST

28vAST4ChannelAEModuleFEATURESFPGAFEATURESFPGAPar1ParaCH1CH2CH3CH44SelectableFILTER

16A/DPCI-DSPBoardBlockDiagramPCI-BUS4SelectableFILTER4SelectableFILTER4SelectableFILTER16A/D16A/D16A/D

DiSP系統(tǒng)結(jié)構(gòu)圖

PCI-DSP4Master(with8Parametrics)8ChannelParametrics&GroupController(In1stBoardOnly)WaveformOptionalModuleDSPBasedChannelControllerHitLED'sSyncAudisPar1Par8CH1CH2CH3CH44ChannelSPMSignalProcessingModulePCI-DSP4Board

HitLED'sSyncAudioPCI-DSP4Board

HitLED'sSyncAudioCH5CH6CH7CH8CH53CH54CH55CH56HitLED'sVideoMouseKeybordPCICOMPUTERBOARDPIIIorP4CPUUSBPrinterCOM1COM2Spares100BasedNetworkCardAudio/AlarmBoardExpansionInterfaceBoardExpansionInterfaceConnectorFor>56CHNetworkvideoKEYBOARDHDiskCDROMfloppyHighSpeedSync&controlWaveformModuleOptionWaveformModuleOption

ISA

PCI-BUSPARAMETRICSSENSORINPUTS

DiSP系統(tǒng)結(jié)構(gòu)流程圖PCI/DSP-4modulewithonboardDSPandautosensortestingch.1ch.2ch.3ch.48-ch.para.inputsPCIslot1PCI/DSP-4modulewithonboardDSPandautosensortestingch.4(n-1)+1ch.4(n-1)+2ch.4(n-1)+3ch.4(n-1)+4PCIslotnPCIBusInterchannelsynchronizationbusPersonalcomputerorindustrialPCchassis12

56通道DiSP系統(tǒng)(112通道SAMOS系統(tǒng))

24通道便攜式DISP系統(tǒng)

48通道便攜式SAMOS系統(tǒng)

32通道SAMOS系統(tǒng)（16通道DiSP系統(tǒng)/8通道PCI-2系統(tǒng)）

12通道微型DISP系統(tǒng)（24通道SAMOS系統(tǒng)）DiSP系統(tǒng)主要功能特色AE特征提取與波形采集實(shí)時(shí)AE波形采集與處理實(shí)時(shí)實(shí)時(shí)采集與信號(hào)處理、濾波DiSP主要AE特征參數(shù)

Hit驅(qū)動(dòng)參數(shù)——

1．幅度Amplitude2．能量Energy3．記數(shù)Counts4．持續(xù)時(shí)間Duration5．RMS信號(hào)均方根值6．ASL平均信號(hào)電平7．上升時(shí)間Risetime8．峰值記數(shù)CountstoPeak9．平均頻率AverageFrequency10.回蕩頻率：ReverberationFrequency:(Count-Counttopeak)/(duration-risetime)11.初始頻率：Initiation(Countstopeak)/(risetime)12.信號(hào)強(qiáng)度：Signalstrength13.絕對(duì)頻率：AbsoluteFrequency

DiSP主要AE特征參數(shù)

時(shí)間驅(qū)動(dòng)參數(shù)——

RMS

ASL

外參數(shù)輸入Parametrics

循環(huán)計(jì)數(shù)CycleCounter

門(mén)檻值Threshold

絕對(duì)能量AbsoluteenergyDiSP主要AE波形參數(shù)FFT分析FFT質(zhì)心：CentroidPartialPower:在FFT功率譜圖上，給出不同頻率段信號(hào)所占的百分比。DiSP頻率濾波4-高通，4-低通隨意組合成13個(gè)濾波段。

多種（實(shí)時(shí)）數(shù)字濾波及信號(hào)處理參數(shù)前端濾波波型前端濾波圖解濾波多參數(shù)分析相關(guān)分析聚類分析2-D，3-D，歷程圖…..衰減曲線/分析…...

ThresholdSettingThresholdSettingseliminatemostbackgroundnoise.Additionaltechniquesareusedtoremovetheremainingbackgroundnoise,ieduration,frequency,etc.FixedThreshold:thethresholdremains"fixed"atthevaluesetbytheuserinthethresholdmenu.Thisthresholdmodeisthecommonmodeofoperationforshorttestsandtestswherethebackgroundnoiseiscontrolledornotvaryinginamajorway.FloatingThreshold:isanadaptivethresholdmode,wherethethresholdchangesindirectrelationtotheRMSofthebackground.Thethresholdlevelsetbytheuseristheminimumthresholdandthisvalueisautomaticallyraisedasthebackgroundnoisevaries.SmartThreshold:isaunique,computerizedadaptivethresholdmodemadepossiblebyPAC'shigh-speed,frontend,digitalsignalprocessing,wherethethresholdchangesinsmallincrements(upordown)basedontheAEactivity(e.g.hits/second)onagivenAEchannel.Thethresholdlevelsetbytheuseristhestartingthresholdforthisprocess.Thishasbeenfoundtobeanextremelyeffectivehit