CN109342574B - Acoustic emission multichannel rapid switching system and switching method - Google Patents
Acoustic emission multichannel rapid switching system and switching method Download PDFInfo
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- CN109342574B CN109342574B CN201811462119.5A CN201811462119A CN109342574B CN 109342574 B CN109342574 B CN 109342574B CN 201811462119 A CN201811462119 A CN 201811462119A CN 109342574 B CN109342574 B CN 109342574B
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- 238000000034 method Methods 0.000 title claims abstract description 11
- 230000005284 excitation Effects 0.000 claims abstract description 42
- 238000002955 isolation Methods 0.000 claims description 5
- 238000003491 array Methods 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 230000001360 synchronised effect Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 description 7
- 238000012360 testing method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 2
- 238000009659 non-destructive testing Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000013480 data collection Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/14—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object using acoustic emission techniques
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
- G01N29/2437—Piezoelectric probes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/34—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/36—Detecting the response signal, e.g. electronic circuits specially adapted therefor
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/023—Solids
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/0289—Internal structure, e.g. defects, grain size, texture
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- General Health & Medical Sciences (AREA)
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- Acoustics & Sound (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
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Abstract
The invention discloses an acoustic emission multichannel rapid switching system and a switching method thereof, wherein the acoustic emission multichannel rapid switching system comprises: the system comprises an even number of piezoelectric interfaces, each piezoelectric interface is respectively and electrically connected with two relays connected in series, in the two relays, two contacts of the relay directly electrically connected with the piezoelectric interfaces are respectively and electrically connected with the other relay and the total relay, and contacts electrically connected with the total relay are switched on when in low level, and two contacts of the other relay are respectively and electrically connected with the data acquisition interface. The acoustic emission multichannel rapid switching system disclosed by the invention not only can flexibly and stably switch the piezoelectric patch interface between two working modes of excitation and acquisition, but also can reduce the number of acquisition channels required. The temporarily-inactive piezoelectric patch interface and the total relay are grounded to ensure that crosstalk signals generated therein can be quickly suppressed.
Description
Technical Field
The invention belongs to the field of nondestructive testing, and particularly relates to an acoustic emission multichannel rapid switching system and a switching method in the field.
Background
Based on the piezoelectric effect and the inverse piezoelectric effect of the piezoelectric sheet, the piezoelectric sheet can be used as an excitation element for excitation and a sensor for signal acquisition. When the piezoelectric sheet works as an excitation element, it needs to be connected to a signal generating device; when the piezoelectric patch is operating as a sensor, it needs to be connected to the acquisition module. If all key nodes of the device are subjected to active and passive damage detection, a large number of sensors are required to be arranged, if one piezoelectric sheet is subjected to data acquisition by one acquisition channel, the number of the acquisition channels of the acquisition module is required to be high, and the acquisition modules of multiple channels are often quite expensive.
Disclosure of Invention
The invention aims to solve the technical problem of providing an acoustic emission multichannel rapid switching system and a switching method capable of enabling a plurality of piezoelectric sheets to time-sharing multiplex acquisition channels.
The invention adopts the following technical scheme:
in an acoustic emission multichannel fast switching system, the improvement comprising: the system comprises an even number of piezoelectric interfaces, each piezoelectric interface is respectively and electrically connected with two relays connected in series, in the two relays, two contacts of the relay directly electrically connected with the piezoelectric interfaces are respectively and electrically connected with the other relay and a master relay, the contacts electrically connected with the master relay are connected in low level, the two contacts of the other relay are respectively grounded and electrically connected with a data acquisition interface, the contacts electrically connected with the data acquisition interface are connected in low level, the two piezoelectric interfaces form a group, one master relay and one data acquisition interface are shared, one of the two contacts of each master relay is grounded, and the other relay is electrically connected with one excitation signal interface, and the system further comprises a control module for controlling the opening and closing of the contacts of each relay and a power module for supplying power to the system.
Further, the number of the piezoelectric patch interfaces is 16, and the number of the data acquisition interfaces is 8.
Further, the contact opening and closing of each relay is controlled through an optocoupler isolation circuit.
Further, the excitation signal interface is an SMA interface.
Furthermore, the power supply module adopts a low ripple circuit design, which comprises two modes of 12V direct current power supply and 220V alternating current power supply, and the 220V alternating current power supply is converted by the power supply voltage reduction module.
Further, the form of the power module power interface includes, but is not limited to, a post interface and a USB interface.
Further, the system also comprises an excitation signal synchronization interface, and the opening and closing of the interface are controlled by the control module through an independent relay.
In a method for acoustic emission multi-channel fast switching using the system described above, the improvement comprising the steps of:
(1) Serial port setting: setting the port number and bit rate of an upper computer sending instructions to a system control module;
(2) Mode selection: in a passive mode, each channel of the data acquisition instrument is electrically connected with each data acquisition interface on the system to form an acquisition channel, so that the system can form a plurality of acquisition channels by a plurality of data acquisition interfaces; in the active mode, besides the content in the passive mode, the signal generator is electrically connected with an excitation signal interface on the system to form an excitation channel;
(3) When the system works in the active mode, an excitation signal synchronous interface on the system can be electrically connected with a signal generator to form a direct-connection channel for recording the generation time of an excitation signal;
(4) The control module enables each piezoelectric patch interface to collect or excite through controlling the opening and closing of each relay contact, and in a passive mode, each two piezoelectric patch interfaces share one collecting channel so as to realize time-sharing multiplexing of the same collecting channel, and when one piezoelectric patch interface is used for collecting, the other piezoelectric patch interface which is temporarily inactive is grounded; in the active mode, except the content in the passive mode, all the total relays share one excitation channel, a piezoelectric patch interface working in the excitation mode is electrically connected with the excitation channel, and a temporarily-inactive piezoelectric patch interface is grounded, so that the piezoelectric patch interface is allowed to neither collect nor excite; the piezoelectric patch interfaces are mutually matched into linear, circular or rectangular arrays for acquisition and/or excitation.
The beneficial effects of the invention are as follows:
the acoustic emission multichannel rapid switching system disclosed by the invention not only can flexibly and stably switch the piezoelectric patch interface between two working modes of excitation and acquisition, but also can reduce the number of acquisition channels required. The interface of the piezoelectric sheet which is temporarily not operated and the total relay are grounded so as to ensure that crosstalk signals generated in the interface can be quickly inhibited, and avoid that the piezoelectric sheet vibrates under the action of the inverse piezoelectric effect after the crosstalk signals are generated, and the vibration can increase the complexity of guided waves in the structure and interfere guided wave detection.
According to the acoustic emission multichannel rapid switching system disclosed by the invention, the power supply module adopts a low-ripple circuit design, so that the influence on the system caused by unstable input voltage can be effectively reduced, and meanwhile, surge current is effectively inhibited. The contact opening and closing of each relay is controlled through an optical coupler isolation circuit, so that the damage to a system caused by instantaneous high current or instantaneous high voltage which is surging under certain special conditions can be avoided.
The acoustic emission multichannel rapid switching method disclosed by the invention can enable each piezoelectric sheet interface to be mutually matched into a linear, circular or rectangular array for acquisition and/or excitation, thereby accurately positioning certain characteristics of a test piece and ensuring that the nondestructive testing result is more ideal.
Drawings
FIG. 1 is a block diagram of the system disclosed in embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of the system disclosed in embodiment 1 of the present invention for performing multi-channel switching;
FIG. 3 is a schematic circuit diagram of an optocoupler isolation circuit in the system disclosed in embodiment 1 of the present invention;
FIG. 4 is a schematic diagram showing the circuit connection of the power module in the system disclosed in embodiment 1 of the present invention;
fig. 5 is a flow chart of a handover method according to embodiment 1 of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
When the structure is detected by active guided wave and passive guided wave, the basic principle is the piezoelectric effect and inverse piezoelectric effect of the piezoelectric sheet. The piezoelectric sheet is placed on a test piece to be tested, the piezoelectric effect of the piezoelectric sheet is utilized to convert an electric signal into a mechanical signal, so that weak vibration is generated and the piezoelectric sheet propagates forwards on the test piece in a wave shape, and other piezoelectric sheets on the test piece to be tested convert the vibration signal into an electric signal (inverse piezoelectric effect) after capturing the vibration signal and transmit the electric signal to the acquisition equipment. In the detection process, the same piezoelectric sheet may be used as an acquisition element immediately after being used as an excitation element, and each piezoelectric sheet on the test piece to be detected is electrically connected to each piezoelectric sheet interface of the system disclosed in the embodiment, so that flexible conversion of the piezoelectric sheets in different working modes can be ensured.
In the embodiment 1, as shown in fig. 1-2, the embodiment discloses an acoustic emission multichannel rapid switching system, the system comprises 16 piezoelectric interfaces 1, each piezoelectric interface is respectively and electrically connected with two relays connected in series, in the two relays, two contacts of the relay directly electrically connected with the piezoelectric interfaces are respectively and electrically connected with the other relay and one general relay, the contacts electrically connected with the general relay are respectively and grounded at a low level, the two contacts of the other relay are respectively and electrically connected with one data acquisition interface 2, the contacts electrically connected with the data acquisition interfaces are connected at a low level, the two piezoelectric interfaces form a group, and one general relay and one data acquisition interface are shared, so that 8 general relays and 8 data acquisition interfaces are totally arranged, one of the two contacts of each general relay is grounded, the other contact is electrically connected with one excitation signal interface 3, the contact electrically connected with the excitation signal interface at a low level, and the system further comprises a power supply module 5 for controlling the power supply module of each relay and the control module.
As shown in fig. 3, the contact opening and closing of each relay is controlled by an optocoupler isolation circuit. The excitation signal interface is an SMA interface.
As shown in FIG. 4, the power supply module adopts a low ripple circuit design, which comprises two modes of 12V direct current power supply and 220V alternating current power supply, and the 220V alternating current power supply is converted by the power supply voltage reduction module. Forms of power module power interface include, but are not limited to, a post interface and a USB interface.
The system also comprises an excitation signal synchronization interface 6, and the opening and closing of the interface is controlled by the control module through an independent relay. The total number of relays 7 in this example embodiment is 41, including 8 total relays, 32 relays corresponding to 16 piezoelectric patch interfaces, and 1 independent relay controlling the switching of the excitation signal synchronization interface.
As shown in fig. 5, this embodiment also discloses a method for fast switching acoustic emission multi-channels, and the system includes the following steps:
(1) Serial port setting: setting the port number and bit rate of an upper computer sending instructions to a system control module;
(2) Mode selection: in a passive mode, each channel of the data acquisition instrument is electrically connected with each data acquisition interface on the system to form an acquisition channel, so that the system can form 8 acquisition channels; in the active mode, besides the content in the passive mode, a signal generator is electrically connected with an excitation signal interface on the system to form 1 excitation channel;
(3) When the system works in the active mode, an excitation signal synchronous interface on the system can be electrically connected with a signal generator to form a direct-connection channel for recording the generation time of an excitation signal;
(4) The control module controls the opening and closing of the contacts of each relay to enable each piezoelectric patch interface to collect or excite, for example, to enable the piezoelectric patch interface of the piezoelectric patch 1 in fig. 2 to collect, the relay 2 needs to be low-level so as to be connected with the contacts electrically connected with the data collection interface; to energize the piezoelectric patch interface of piezoelectric patch 16 in fig. 2, relay 40 needs to be low to make its contacts electrically connected to the overall relay 36, and the overall relay 36 needs to be low to make its contacts electrically connected to the energizing signal interface. In a passive mode, each two piezoelectric patch interfaces share one acquisition channel so as to realize time-sharing multiplexing of the same acquisition channel, and when one piezoelectric patch interface is used for acquisition, the other piezoelectric patch interface which does not work temporarily is grounded; in the active mode, except the content in the passive mode, all the total relays share one excitation channel, a piezoelectric patch interface working in the excitation mode is electrically connected with the excitation channel, and a temporarily-inactive piezoelectric patch interface is grounded, so that the piezoelectric patch interface is allowed to neither collect nor excite; the piezoelectric patch interfaces are mutually matched into linear, circular or rectangular arrays for acquisition and/or excitation.
Claims (8)
1. An acoustic emission multichannel fast switching system, characterized in that: the system comprises an even number of piezoelectric interfaces, each piezoelectric interface is respectively and electrically connected with two relays connected in series, in the two relays, two contacts of the relay directly electrically connected with the piezoelectric interfaces are respectively and electrically connected with the other relay and a master relay, the contacts electrically connected with the master relay are connected in low level, the two contacts of the other relay are respectively grounded and electrically connected with a data acquisition interface, the contacts electrically connected with the data acquisition interface are connected in low level, the two piezoelectric interfaces form a group, one master relay and one data acquisition interface are shared, one of the two contacts of each master relay is grounded, and the other relay is electrically connected with one excitation signal interface, and the system further comprises a control module for controlling the opening and closing of the contacts of each relay and a power module for supplying power to the system.
2. The acoustic emission multi-channel fast switching system of claim 1, wherein: the number of the piezoelectric patch interfaces is 16, and the number of the data acquisition interfaces is 8.
3. The acoustic emission multi-channel fast switching system of claim 1, wherein: the contact opening and closing of each relay is controlled by an optocoupler isolation circuit.
4. The acoustic emission multi-channel fast switching system of claim 1, wherein: the excitation signal interface is an SMA interface.
5. The acoustic emission multi-channel fast switching system of claim 1, wherein: the power supply module adopts a low-ripple circuit design, and comprises two modes of 12V direct current power supply and 220V alternating current power supply, wherein the 220V alternating current power supply is converted by the power supply voltage reduction module.
6. The acoustic emission multi-channel fast switching system of claim 5, wherein: forms of power module power interface include, but are not limited to, a post interface and a USB interface.
7. The acoustic emission multi-channel fast switching system of claim 1, wherein: the system also comprises an excitation signal synchronization interface, and the opening and closing of the interface are controlled by the control module through an independent relay.
8. An acoustic emission multi-channel fast switching method using the system of claim 7, comprising the steps of:
(1) Serial port setting: setting the port number and bit rate of an upper computer sending instructions to a system control module;
(2) Mode selection: in a passive mode, each channel of the data acquisition instrument is electrically connected with each data acquisition interface on the system to form an acquisition channel, so that the system can form a plurality of acquisition channels by a plurality of data acquisition interfaces; in the active mode, besides the content in the passive mode, the signal generator is electrically connected with an excitation signal interface on the system to form an excitation channel;
(3) When the system works in the active mode, an excitation signal synchronous interface on the system can be electrically connected with a signal generator to form a direct-connection channel for recording the generation time of an excitation signal;
(4) The control module enables each piezoelectric patch interface to collect or excite through controlling the opening and closing of each relay contact, and in a passive mode, each two piezoelectric patch interfaces share one collecting channel so as to realize time-sharing multiplexing of the same collecting channel, and when one piezoelectric patch interface is used for collecting, the other piezoelectric patch interface which is temporarily inactive is grounded; in the active mode, except the content in the passive mode, all the total relays share one excitation channel, a piezoelectric patch interface working in the excitation mode is electrically connected with the excitation channel, and a temporarily-inactive piezoelectric patch interface is grounded, so that the piezoelectric patch interface is allowed to neither collect nor excite; the piezoelectric patch interfaces are mutually matched into linear, circular or rectangular arrays for acquisition and/or excitation.
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| DE19860127C1 (en) * | 1998-12-17 | 2000-10-26 | Mannesmann Ag | Ultrasonic testing head for non-destructive materials testing uses individual piezoelectric elements coupled in pairs to common input channels with summation of their output signals for each output channel |
| CN1595183A (en) * | 2003-09-09 | 2005-03-16 | 华为技术有限公司 | Test circuit and test method thereof |
| CN201449411U (en) * | 2009-07-02 | 2010-05-05 | 苏州经贸职业技术学院 | Multichannel current sampling circuit |
| CN101872194A (en) * | 2010-06-30 | 2010-10-27 | 南京航空航天大学 | Low-crosstalk, rapid and active-passive compatible type piezoelectric channel switching system and realization method thereof |
| CN103425107A (en) * | 2013-08-13 | 2013-12-04 | 南京航空航天大学 | Multiple piezoelectric channel program-controlled switching system |
| CN203883859U (en) * | 2014-05-30 | 2014-10-15 | 国家电网公司 | Multi-gate attenuation network system based on relay array |
| CN209231276U (en) * | 2018-12-03 | 2019-08-09 | 中国海洋大学 | A kind of sound emission multichannel fast switching system |
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2018
- 2018-12-03 CN CN201811462119.5A patent/CN109342574B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| DE19860127C1 (en) * | 1998-12-17 | 2000-10-26 | Mannesmann Ag | Ultrasonic testing head for non-destructive materials testing uses individual piezoelectric elements coupled in pairs to common input channels with summation of their output signals for each output channel |
| CN1595183A (en) * | 2003-09-09 | 2005-03-16 | 华为技术有限公司 | Test circuit and test method thereof |
| CN201449411U (en) * | 2009-07-02 | 2010-05-05 | 苏州经贸职业技术学院 | Multichannel current sampling circuit |
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