PXWAE engineering version of the core of the digital full waveform acoustic emission instrument for the physical acoustics company PCI bus using DMA technology of PCI - 8 AE card, each PCI - 8 8 AE channel card independent processing, several PCI card of multi_channel acoustic emission system. And because the standard PCI bus structure, a set of multi_channel acoustic emission of SAMOS system card can be installed in any standard PC computer and split into several different channels for acoustic emission system. PCI - 8 card core hardware for 16 bit A/D, multipleFPGA and DSP real_time AE characteristic parameters (CPU) acquisition and analysis. All AE characteristic parameters collection/analysis, waveform acquisition/analysis are made by card on the curing of FPGA and DSP, so the hardware structure of the maximum core features as parallel DSP processing technology (parallel processing and parallel DSP CPU). Unlike other acoustic emission system based on general A/D card (most of the work of AE signal processing by the backend PC's CPU to handle), PCI - 8 - most of the AE signal acquisition/processing work (including AE characteristic parameters collection/analysis, waveform sampling/analysis, etc.) are made by PCI - 8 card hardware CPU (FPGA and DSP); Also don't like other non_standard bus structure of AE system of the whole system and PC computer data communication is through the nonstandard bus communication line connection, the communication speed is only a few megabytes per second, PCI - 8system USES standard PCI bus structure, with the computer communications at the rate of 132 MB/SECAnd PCI - 8 card with the latest computer DMA technology, its maximum limit for PCI - 8 card exchange processing with the computer CPU, memory, and maximize the use of computer hardware resources. These characteristics is very important, because a large number of acoustic emission after decades of research/application show that the acoustic emission testing technology of data/signal processing are often very large, is unmatched by other detection technology. And because the actual problem of the acousticemission phenomenon itself is characteristic with irreversible or unrepeatable, acoustic emission processing system is required not only maximize the AE signal real_time acquisition, and maximize the AE signal analysis/processing, more for the work to be real_time, including with the computer communications and storage.
Tell from the AE processing functions, the use of parallel DSP processing technology of PCI - 8 system not only has a real_time synchronous data acquisition/analysis of AE parameters and the signal waveform features, more able to AE characteristic parameters real_time processing including: correlation analysis and parameter analysis and various kinds of digital filter algorithm processing; For AE signal waveform, the waveform acquisition/store is not only simple, better real_time waveform analysis and calculation, including: real_time FFT function, real_time computing center frequency, frequency, waveform characteristics such as the percentage of each frequency distribution analysis. These are the bidding products unique technical characteristics.
In addition, PCI - 8 system in addition to AE signal processing, and synchronous processing and AE channels have the same number of input parameters, including: load, temperature, stress/strain parametersthereof.
PCI - 8 main signal collection and processing functions are as follows:
A variety of time domain and frequency domain feature extraction: 14 time domain features can be extracted with six frequency domain feature
Real time synchronization feature extraction and waveform acquisition: record in feature extraction can be collected at the same time storage response waveform
Channel selection optional choose is used by the AE channel number and channel number
A/D sampling rate Settings: A variety of optional sampling rate
Hit and wave length setting: flexible set Hit and wave length
Including: fixed value the threshold value is set floating threshold value and intelligence
Online threshold correction: in the detection process is not interrupt to modify the threshold
Parameter record setting parameter input (8) : record synchronization with acoustic emission signal load parameters temperature and stress/strain thereof
Fatigue cycle count set: when the fatigue test can real time record number of fatigue
Time door voltage function: the function is used for fatigue test load cycle AE acquisition. To remove from the crack surface friction noise Other friction noise is very useful. In PAC company's previous equipment the function by independent hardware to implement (option). In aPCI - 8 system the function has been integrated in PCI - 8 card (optional)
Hit AE characteristics of driver Settings: including 15 characteristic parameter setting and acquisition
Driven time parameter setting and acquisition (8) : in addition to the AE characteristics of acoustic emission Hit drive also can wait time interval to extract acoustic emission characteristics
Three important parameters HDT PDT HLT Settings: can control the length of the Hit signal and acquisition rate
Front end filtering (characteristics of AE HIT) : rise time of each channel the peak number number energy duration and amplitude the average frequency digitization of main AE characteristic parameters such as filter Settings. For signal did not meet the requirements of filter set will not be collecting and processing. The function to remove noise signal or active acquisition of AE signal is very useful.
Waveform front-end filtering: setting up meet the filter conditions of AE waveform recording.
Graphic filter: a variety of digital filtering processing in the graphical display.
Alarm Settings the user can according to the actual inspection situation set up alarm in different ways such as the signal acquisition according to the characteristics of the signal itself to choose the front end of the alarm; In view of the graphics and filtering conditions set graphics alarm; According to the characteristics of clustering analysis in the process of testing conditions on the implementation of state police
Audio Settings: can be set up freely for any channel Hit audio alarm audio and the audio intensity frequency etc
Through Internet remote communication function: can be on the scene of the acoustic emission system for remote operation and monitoring and testing process
Automatic sensor test (AST) : any one channel can be used to transmit and receive width and speed adjustable sound pulse to verify that the sensor coupling condition (unlike other equipment is only one independent module produce pulse signal other sensors can only acceptsignals)
To be sure: PCI - 8 band pass filter function the front end filtering function the wave front filtering and the selection of PDT HDT HLT Settings is based on a large number of AE in decades experience of engineering application for AE application under various environmental noise removal and needed to collect useful AE signals are very useful. And many of the functions and Settings are most of the acoustic emission standards referenced such as the PDT HDT HLT Settings and so on. In addition the increase of the floating threshold setting andsmart threshold setting method greatly improved the disadvantages of traditional fixed threshold set is very useful to AE application under complicated background noise.
Acquisition/processing by PCI - 8 main parameters:
Hit drive parameters --
1. The Amplitude of Amplitude
2. Energy Energy
3. The numeration Counts
4. The last time Duration
5. The RMS signal RMS values
6. ASL average signal level
7. Rise time Rise time
8. Peak Counts to Peak
9. The Average Frequency of Average Frequency
10. Reverberation echo Frequency Frequency (Count - Count to peak)/(duration - rise time)
11. The initial frequency Initiation (Counts to peak)/(rise time)
12. The Signal intensity of Signal strength
13. The Absolute Energy Absolute Energy
14. The Threshold Threshold
15. Frequency domain Centroid Frequency Centroid
16. The Peak Frequency Peak Frequency
17_20.Regional Power spectrum (4) Partial Power:in FFT Power spectrum diagram the user can define any four frequency to the percentageof different frequency signals is given.
In addition the Hit to drive parameters include Hit parameter input cycle count waveform and FFT etc.
Time driving parameters --
1. The RMS signal RMS values
2. ASL average signal level
3. The outside parameter input Parametrics
4. The loop count Cycle Counter
5. The Threshold value Threshold
6. Absolute energy Absolute energy
To be sure: the above 20 Hit drive AE characteristic parameters and six time drive characteristic parameters are real_time collection/analysis/processing. And are made by PCI - 8 card's hardware implementation.
PCI - 8 system due to adopting standard PCI bus structure not only the data is open can separate form AE characteristic parameters and the waveform of the ASCII format. But also can provide PCI - 8 card to the bottom of the development environment is C dynamic link libraries SDK and used in LAB VIEW development driver of PCI BOARD LAB VIEW software. Users can be hardware programming according to different needs for different realtime collection and processing system. And PCI - 8 card can be embedded in other systems or control other hardware integrated acquisition or control system process control for example flexible manufacturing integrated diagnosis/control system.
The main technical characteristics of the product
PCI bus structure/CAT/parallel DSP system;
PCI - 8 card can be in any PC computer constitute a complete acoustic emission system independently;
Parallel DMA technology;
Each independent 16 channels
+ / - 10 v input to ensure that the standard of 40 db gain Settings signal amplitude largest of 100 db. The other similar products of the A/D input range is + / - 5 v its dynamic range is far less than + / - 10 v under 40 db gain Settings its biggest signal amplitude is only 94 db.
> 82 db dynamic range (if the A/D input is + / - 5 v it is hard to reach that level);
Hardware filtering: controlled by software combination can be freely according to different situation of 13 frequency filtering section in order to realize the filter frequency is set up according to different situation. Such as for steel pressure vessels should be adopt high frequencyfrequency Settings; For aluminum containers choosing the low frequency Settings. For tank blank test need to choose a lower frequency range. Other similar products for different frequency range such as pressure vessel and tank blank test need to remove the system replace all acoustic emission collection module on the hardware filtering component.
Three kinds of threshold value is set: fixed floating intelligent;
To gain three Settings: before 20 dB 40 dB 60 dB (this is the international general Settings as opposed to some equipment adopt 34 dB or 43 dB Settings).
AE signal parameters real-time front-end digital filtering;
The AE signal waveform real-time front-end digital filtering;
A variety of functions of graphics filter;
AE parameters and waveform characteristic parameters of the multi_parameter analysis correlation analysis 2_d / 3_d graphic analysis chart diagram histogram the statistical figure;
Hit parameters - waveform/FFT link analysis;
E activity of cluster analysis;
From the analysis of AE characteristic parameters of AE waveform are extracted/calculation;
AEWinpost rich after analysis software function;
Wavelet analysis short-time FFT frequency Dispersion Curve (Dispersion Curve) functions such as package;
For complex problems complex signal strong/neural network pattern recognition software package (separate);
Take the AST - automatic sensor test function standard function;
To the problem of generalized acoustic emission for acoustic emission signal problems (such as friction leakage etc.) special processing capacity.
Dynamic link libraries provide the SDK and used in LAB VIEW development tools package;
The key characteristic of positioning function is as follows:
O random positioning function: both sensors can be arbitrary root layout is no longer restricted by fixed line triangle and quadrilateral shape greatly convenient for application.
Eight o standard positioning group (32 optional) each group can be applied in acoustic emission system all of the channels. Mouse operation probe position setting the probe position can be artificially by click or drag the mouse to achieve triangular probe layout automatically set can also be simply by dragging or input probe location coordinates to edit the probe position coordinates list.
O variety of one-dimensional two-dimensional and three-dimensional positioning model.
O the flexible clustering analysis clustering analysis and statistics are available at any point of the picture (not only limited to the location map).
O the user can easily set to display the selected different positioning structure. Optional items include: plate horizontal and vertical container vessel spherical and free way to easily set above each structure are detailed corresponding Settings menu include automatic or manual probe layout weld nozzle and so on.
O through the easy setup and position setting and display the results of plane figure including: probe grid lines attenuation figure weld and nozzle etc.
O senior position setting event detection can provide improved classification and accurate source location technology.
O rich software analysis function has a variety of super afterwards analysis function including adjusting speed of sound time_base trigger principle material localization algorithm correction and so on various locating accuracy analysis and so on.