美国PAC声发射仪器

PAC公司多通道全数字化声发射检测系统PAC数字化AE发展过程80’SLocan+TRA2.5ET，Turnkeysystem90’S初SPARTAN+TRA21294年：第一代全数字化Mistras2001(AEDSP)99年底：第二代全数字化DiSP系统（4通道PCI总线）2001,DiSPVer5.0版(硬件X3，DMA）2002：PCI-8（SAMOS）2003：PCI-2PAC公司数字化声发射技术特征自90年代中期以AEDSP卡构成的MISTRAS2001系统的成功问世标志PAC公司的AE技术进入DSP数字化时代。PAC发展AE技术的综旨：高速、高效、实时、可靠最大限度采用现代硬件技术最大限度解决当今AE问题PAC公司技术特点：DSP技术并行DSP技术并行处理DISP的系统基于4通道AE卡——PCI/DSP-4SAMOS系统的8通道AE卡——PCI-8PCI-8HFCard•8CompleteAEChannelsonasinglePCIcard•UsesSMBConnectors•3MS/sec,16bitA/D.•2Parametricsperboard•4High,4LowPassfilters•1-400kHzbandwidth.•MultipleFPGA’swithReal-TimeFeatureExtraction•Built-inwaveformswithfixed4Ksamplelength(8kbytes)usingcircularbuffers.2Analog,16DigitalParametricControllerPreampPowerDAC4SelectableFilters4SelectableFiltersBuffer/AmplifierBoardControllerCh.8Ch.2Ch.1CHANNELBLOCK#8AEInCHANNELBLOCK#2AEInDSPControlLinesCHANNELBLOCK#1ASTProg.HPFilterProg.LPFilterProgrammableGainAmplifierPCI-BUSPCIController16BitA/DRealTimeFeatureExtractAEIn2通道AE卡——PCI-2系统主要技术特点全数字化计算机一体化CAT系统并行DSP处理系统高速DMA技术结构化设计16位A/D（PCI-2为18位A/D）PCI总线AE特征参数/波形同时进行16A/DPARAMETRICSAEINPUTS8ChannelParametrio&GroupController(In1stBoardOnly)DSPBased4ChannelWaveformModuleOptionalDSPBasedChannelControllerAndPCIBusInterfaceCircuitry28vAST28vAST28vAST28vAST4ChannelAEModuleFEATURESFPGAFEATURESFPGAPar1ParaCH1CH2CH3CH44SelectableFILTER16A/DPCI-DSPBoardBlockDiagramPCI-BUS4SelectableFILTER4SelectableFILTER4SelectableFILTER16A/D16A/D16A/DDiSP系统结构图PCI-DSP4Master(with8Parametrics)8ChannelParametrics&GroupController(In1stBoardOnly)WaveformOptionalModuleDSPBasedChannelControllerHitLED'sSyncAudisPar1Par8CH1CH2CH3CH44ChannelSPMSignalProcessingModulePCI-DSP4BoardHitLED'sSyncAudioPCI-DSP4BoardHitLED'sSyncAudioCH5CH6CH7CH8CH53CH54CH55CH56HitLED'sVideoMouseKeybordPCICOMPUTERBOARDPIIIorP4CPUUSBPrinterCOM1COM2Spares100BasedNetworkCardAudio/AlarmBoardExpansionInterfaceBoardExpansionInterfaceConnectorFor56CHNetworkvideoKEYBOARDHDiskCDROMfloppyHighSpeedSync&controlWaveformModuleOptionWaveformModuleOptionISAPCI-BUSPARAMETRICSSENSORINPUTSDiSP系统结构流程图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)+4PCIslotnInterchannelsynchronizationbusPersonalcomputerorindustrialPCchassis56通道DiSP系统(112通道SAMOS系统)24通道便携式DISP系统48通道便携式SAMOS系统32通道SAMOS系统（16通道DiSP系统/8通道PCI-2系统）12通道微型DISP系统（24通道SAMOS系统）DiSP系统主要功能特色AE特征提取与波形采集实时AE波形采集与处理实时实时采集与信号处理、滤波DiSP主要AE特征参数Hit驱动参数——1．幅度Amplitude2．能量Energy3．记数Counts4．持续时间Duration5．RMS信号均方根值6．ASL平均信号电平7．上升时间Risetime8．峰值记数CountstoPeak9．平均频率AverageFrequency10.回荡频率：ReverberationFrequency:(Count-Counttopeak)/(duration-risetime)11.初始频率：Initiation(Countstopeak)/(risetime)12.信号强度：Signalstrength13.绝对频率：AbsoluteFrequencyDiSP主要AE特征参数时间驱动参数——RMSASL外参数输入Parametrics循环计数CycleCounter门槛值Threshold绝对能量AbsoluteenergyDiSP主要AE波形参数FFT分析FFT质心：CentroidPartialPower:在FFT功率谱图上，给出不同频率段信号所占的百分比。DiSP频率滤波4-高通，4-低通随意组合成13个滤波段。多种（实时）数字滤波及信号处理参数前端滤波波型前端滤波图解滤波多参数分析相关分析聚类分析2-D，3-D，历程图…..衰减曲线/分析…...ThresholdSettingThresholdSettingseliminatemostbackgroundnoise.Additionaltechniquesareusedtoremovetheremainingbackgroundnoise,ieduration,frequency,etc.FixedThreshold:thethresholdremainsfixedatthevaluesetbytheuserinthethresholdmenu.Thisthresholdmodeisthecommonmodeofoperationforshorttestsandtestswherethebackgroundnoiseiscontrolledornotvaryinginamajorway.FloatingThreshold:isanadaptivethresholdmode,wherethethresholdchangesindirectrelationtotheRMSofthebackground.Thethresholdlevelsetbytheuseristheminimumthresholdandthisvalueisautomaticallyraisedasthebackgroundnoisevaries.SmartThreshold:isaunique,computerizedadaptivethresholdmodemadepossiblebyPAC'shigh-speed,frontend,digitalsignalprocessing,wherethethresholdchangesinsmallincrements(upordown)basedontheAEactivity(e.g.hits/second)onagivenAEchannel.Thethresholdlevelsetbytheuseristhestartingthresholdforthisprocess.Thishasbeenfoundtobeanextremelyeffectivehitdetectionmethod.PCI-2特点18位A/D，40MHZ采样；Streamingfunction连续波形处理；广义AE应用；嵌入式结构—并行硬件；开放式系统—SDK，LabViewdriver最好的研发工具；柱状容器定位球面定位AEWINNOESISPatternRecognitionSoftwareNeuralNetwork&PatternRecognitionSoftwareforAE&NDTPACWaveletSoftware