CN113933391A - Piezoelectric ultrasonic guided wave detection device and detection method - Google Patents
Piezoelectric ultrasonic guided wave detection device and detection method Download PDFInfo
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Abstract
The invention provides a piezoelectric ultrasonic guided wave detection device and a detection method, comprising the following steps: the device comprises a main control module, a driving circuit module, a monitoring circuit module, a temperature detection module, a strain detection module, at least two piezoelectric sensing elements, at least one temperature sensing element and at least one strain sensing element; the main control module is connected with at least one first piezoelectric sensing element through the driving circuit module, and at least one second piezoelectric sensing element is connected with the main control module through the monitoring circuit module; the main control module is connected with at least one temperature sensing element through a temperature monitoring module; the main control module is connected with at least one strain sensing element through a strain monitoring module; the invention realizes the stable control of the transmitting signal, eliminates the resonance of the transmitting signal and reduces the noise of the transmitting signal; the short circuit of the piezoelectric sensing element is protected in time and alarm prompt is realized; the elimination of the crosstalk between channels is realized; the applicability of the instrument under different working conditions is improved.
Description
Technical Field
The invention relates to the field of structural health monitoring, in particular to a detection device and a detection method based on piezoelectric ultrasonic guided waves.
Background
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The structural health monitoring is the description of whether the structure is in a normal working state or not. The method comprises the steps of obtaining structural operation parameters by using a sensor, obtaining characteristic information required by health state diagnosis through data processing, realizing state monitoring, fault diagnosis, prediction and the like of the structure by fusing various types of characteristic information, and generating health state information available for maintenance and decision.
Piezoelectric sensing elements, also called piezoelectric transducers, are devices that convert electrical energy and acoustic energy into each other by using the piezoelectric effect of certain single crystal materials and the electrostrictive effect of certain polycrystalline materials.
The ultrasonic guided wave detection technology is an implementation mode of structural health monitoring, guided waves are used as transmission media of damage information, an array formed by multiple piezoelectric sensing elements is used for exciting the guided waves on a structure, and guided wave response signals after interaction with damage are collected. And processing the acquired response signals, extracting signal characteristics such as amplitude, phase, frequency spectrum and the like in the waveform, and then carrying out signal characteristic analysis to identify and position structural damage.
The traditional piezoelectric ultrasonic detection instrument has the following defects:
(1) the transmitting waveform of the driving piezoelectric sensing element cannot be accurately controlled, the waveform harmonic component is large, and the waveform is easy to resonate at high frequency, so that the system stability is relatively poor;
(2) short circuit of the piezoelectric sensing element cannot be protected in time;
(3) crosstalk between channels due to waveform emission cannot be effectively reduced.
(4) Because different materials attenuate ultrasonic waves to different degrees, received signal amplitudes of different materials have hundreds of times of difference under the same transmitted signal, and therefore a single device cannot monitor various types of structures such as aluminum alloy and composite materials at the same time.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a piezoelectric ultrasonic guided wave detection device and a detection method, which can accurately control the emission waveform of a piezoelectric sensing element, reduce the harmonic component of the waveform, eliminate the oscillation of the waveform and improve the consistency of the emission waveform; the short circuit of the piezoelectric sensing element can be protected in time and alarm prompt is realized; crosstalk signals between channels can be inhibited; the adaptive amplification can be realized aiming at response signals with different amplitudes.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a piezoelectric ultrasonic guided wave detection device in a first aspect.
A piezoelectric ultrasonic guided wave detection device comprising: the device comprises a main control module, a driving circuit module, a monitoring circuit module, a temperature detection module, a strain detection module, at least two piezoelectric sensing elements, at least one temperature sensing element and at least one strain sensing element.
The main control module is connected with at least one first piezoelectric sensing element through the driving circuit module, and at least one second piezoelectric sensing element is connected with the main control module through the monitoring circuit module; the main control module is connected with at least one temperature sensing element through a temperature monitoring module; the main control module is connected with at least one strain sensing element through the strain monitoring module.
The main control module is used for judging the structural defects by combining the temperature and the strain information of the structure according to the received response signals of the second piezoelectric sensing element.
Furthermore, the driving circuit module comprises an arbitrary waveform generation module, a program-controlled amplification module, a program-controlled band-pass filtering module, a broadband power amplification module, a short-circuit protection module, an impedance matching module, a shock elimination module and a piezoelectric sensing element selection module which are sequentially connected.
Furthermore, the arbitrary waveform generating module adjusts parameters of the output waveform according to the requirement of the transmitting signal and the instruction of the main control module, and generates a driving waveform with specific amplitude, frequency and phase.
Furthermore, the program control amplification module adjusts the gain of the module according to the amplitude requirement of the transmitting signal and the instruction of the main control module, and amplifies the transmitting signal by different times.
Furthermore, the program-controlled band-pass filtering module is used for carrying out filtering frequency band configuration according to the frequency of the transmitting signal and the instruction of the main control module, and filtering low-frequency noise and high-frequency noise generated by the preceding stage.
Furthermore, the broadband power amplification module is used for carrying out power amplification of fixed times on the transmitting signal, and improving the output voltage and the driving capability.
Furthermore, the short-circuit protection module utilizes the triode to build a self-recoverable bidirectional short-circuit protection circuit for overcurrent protection during short circuit of the first piezoelectric sensing element.
Furthermore, the impedance matching module utilizes the resistor, the capacitor and the inductor to build a matching circuit, so that the matching of the output impedance of the device and the impedance of the piezoelectric sensing element is realized, and the energy loss of the transmitted signal is reduced.
Furthermore, the oscillation eliminating module utilizes the main control module to control the on-off of the bidirectional thyristor, so that the oscillation of the transmitting signal is eliminated.
Furthermore, the transmitting sensing element selecting module is used for selecting at least one piezoelectric sensing element from the plurality of piezoelectric sensing elements as a first piezoelectric sensing element for transmitting.
Furthermore, the monitoring circuit module comprises a piezoelectric sensing element selection module, a single-path speed switch module, a primary amplification module, a multi-stage program control amplification module, a program control band-pass filtering module, a fixed gain attenuation module and a data sampling module which are sequentially connected.
Further, the receiving piezoelectric sensing element selecting module is used for selecting at least one piezoelectric sensing element from the plurality of piezoelectric sensing elements as a second piezoelectric sensing element for receiving.
Furthermore, the single-path fast switch module is opened before the excitation signal is ended and closed after the excitation signal is ended, is used for eliminating the crosstalk signals in the response signal, and is controlled by the instruction of the main control module to open and close.
Furthermore, the primary signal amplification module adopts the precise operational amplifier to carry out primary amplification of fixed times on the response signal.
Furthermore, the multi-stage program control amplification module is realized by adopting a plurality of operational amplifiers with adjustable gains in cascade connection, and the gain of each operational amplifier is configured according to the instruction of the main control module.
Furthermore, the program-controlled band-pass filtering module is used for carrying out filtering frequency band configuration according to the frequency of the transmitting signal and the instruction of the main control module, and filtering low-frequency and high-frequency noises in the response signal.
Furthermore, the fixed gain attenuation module performs fixed gain amplitude attenuation on the transmission signal without changing the frequency and the phase of the transmission signal.
Furthermore, the high-speed data sampling module performs analog-to-digital conversion on the attenuated transmission signal and the amplified response signal.
Furthermore, the temperature detection module comprises a long line driving module and a temperature channel selection module which are sequentially connected.
Furthermore, the long-line driving module improves the driving capability of the temperature signal so as to adapt to the long-distance transmission of the signal.
Furthermore, the temperature channel selection module is used for selecting at least one of the plurality of temperature sensing elements to be connected.
Furthermore, the strain detection module comprises a long line driving module and a strain channel selection module which are sequentially connected.
Furthermore, the long-line driving module improves the driving capability of the strain signal so as to adapt to the long-distance transmission of the signal.
Further, the strain channel selection module is used for selecting at least one of the plurality of strain sensing elements to be connected.
The second aspect of the present invention provides a piezoelectric ultrasonic guided wave detection method, which utilizes the above piezoelectric ultrasonic guided wave detection apparatus, and includes the following processes:
the piezoelectric sensing elements, the temperature sensing element and the strain sensing element are arranged on the structure body to be measured;
the main control module drives a certain first piezoelectric sensing element to transmit a preset waveform signal by using the driving circuit module, the frequency and the phase of the transmitted signal are adjusted by the arbitrary waveform generation module, and the amplitude of the transmitted signal is adjusted by the arbitrary waveform transmission module and the program control amplification module together;
the main control module filters noise of other frequency bands in the transmitting signal by utilizing an adjustable band-pass filtering module according to the frequency of the transmitting signal;
the main control module controls the oscillation eliminating module to eliminate oscillation of the transmitted waveform according to the end time of the transmitted signal;
the main control module controls the transmitting sensing element selection module, and selects at least one first piezoelectric sensing element for transmitting from the plurality of piezoelectric sensing elements;
the main control module receives a response signal of a certain second piezoelectric sensing element by using the monitoring circuit module. The main control module controls the receiving sensing element selection module to select at least one second piezoelectric sensing element for receiving from the plurality of piezoelectric sensing elements;
the main control module controls the action of the single-path fast switch according to the end time of the law case emission signal, and eliminates the crosstalk influence in the response signal;
the main control module adaptively adjusts the gain of the multi-stage programmable control amplification module according to the amplitude of the response signal; the main control module filters noise of other frequency bands in the response signal by using an adjustable band-pass filtering module according to the frequency of the transmission signal;
the main control module samples the attenuated transmitting signal and the amplified response signal by using a high-speed data sampling module;
the main control module receives structural temperature information acquired by a certain temperature sensing element by using the temperature detection module, controls the temperature channel selection module, selects at least one of the temperature sensing elements as the temperature sensing element and acquires the structural temperature information;
the main control module receives structural strain information acquired by a certain strain sensing element by using the strain detection module, controls the strain channel selection module, selects at least one strain sensing element from the plurality of strain sensing elements as the strain sensing element, and acquires the structural strain information;
the main control module judges the structural damage according to the change of the response signal received by the second piezoelectric sensing element and by combining the temperature information and the strain information of the structure.
Compared with the prior art, the invention has the beneficial effects that:
1. the device and the method of the invention firstly set a proper filter passband range by the main control module according to the frequency of the transmitting signal, and filter the noise interference which is different in frequency with the transmitting signal in the transmitting signal by controlling the cut-off frequency and the bandwidth of the program control bandpass filter module in the drive circuit. Secondly, an impedance matching module in the driving circuit matches the output impedance of the device with the piezoelectric sensing element, and the oscillation eliminating module discharges the reflected oscillation energy of the transmitting signal, so that the reflected oscillation phenomenon of the transmitting signal can be reduced, and the consistency of the transmitting signal is improved. And finally, attenuating the transmitted signal by using a fixed gain attenuation module, accurately sampling the transmitted signal by using a main control module, and readjusting the excitation waveform according to sampling information, thereby realizing accurate control of the waveform. The above measures ensure the consistency and stability of the transmitted waveform. In addition, the monitoring part module also uses a program control band-pass filtering module, so that the noise and harmonic component of the response signal can be effectively reduced, and the high stability of the system is further ensured.
2. According to the device and the method, the short-circuit protection module capable of self-recovering is designed in the drive circuit part. When the first piezoelectric sensing element is short-circuited, the circuit can automatically send out an alarm signal and limit overlarge current output; when the short circuit phenomenon is recovered to normal, the circuit can automatically recover the normal working state and cancel the alarm signal. When the sensing element is short-circuited, the detection device can give an alarm to prompt the maintenance, and the conditions of instrument damage and the like caused by the short circuit of the piezoelectric sensing element are avoided.
3. According to the device and the method, the monitoring circuit part uses a single-way quick switching circuit, and the action of the single-way quick switching circuit is controlled by the main control module. Before the transmission of signals is finished, the switch is in an open state, and the main control module controls the switch to be quickly closed in the first time of finishing the transmission of signals, so that the device can amplify and sample the signals after the transmission is finished and ignore crosstalk signals which simultaneously appear with the transmission signals, and the influence on response caused by crosstalk between channels is effectively eliminated.
4. In the device and the method, the monitoring circuit part of the instrument uses the programmable control amplifying circuit with adjustable gain, and a multistage gain adjustable amplifier is used for cascade connection in order to improve the gain adjusting range as much as possible. The main control module automatically adjusts the gain of the program control amplification according to the amplitude of the response signal of the second piezoelectric sensing element, the signal-to-noise ratio of the response signal is improved as much as possible, the amplitude difference of the response signal caused by the factors such as the material to be detected and the monitoring range is reduced, the adaptive adjustment of the gain under different working conditions is realized, and the damage identification precision is improved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
Fig. 1 is a schematic structural diagram of a piezoelectric ultrasonic guided-wave detection apparatus provided in embodiment 1 of the present invention.
Fig. 2 is a schematic circuit diagram of a short-circuit protection module according to embodiment 2 of the present invention.
Fig. 3 is a circuit schematic diagram of an oscillation cancellation module according to embodiment 3 of the present invention.
Fig. 4 is an effect diagram of the oscillation elimination module according to embodiment 3 of the present invention.
Detailed Description
The invention is further described with reference to the following figures and examples.
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
Example 1:
as shown in fig. 1, embodiment 1 of the present invention provides a piezoelectric ultrasonic guided wave detection apparatus, including: driving and monitoring of the piezoelectric sensing element, and monitoring of the temperature sensing element and the strain sensing element.
When the piezoelectric sensing elements are used for monitoring structural damage, the piezoelectric sensing elements are pasted on a structure to be tested, one piezoelectric sensing element is used for emitting a high-voltage driving signal, the other piezoelectric sensing element is used for receiving a response signal, and if the structure is damaged, the response signal carries damaged information.
Therefore, the piezoelectric sensing element part mainly comprises a driving circuit and a monitoring circuit, and a main control module is used for carrying out overall coordination control on all circuits of the whole instrument.
The driving part of the piezoelectric sensing element consists of functional modules of arbitrary waveform generation, program control amplification, program control band-pass filtering, broadband power amplification, short circuit protection, impedance matching, oscillation elimination, emission sensing element selection and the like.
The waveform generation module adjusts parameters of output waveforms according to the requirements of the transmission signals and the instructions of the main control module, and generates driving waveforms with specific amplitudes, frequencies and phases. In this embodiment, the waveform generation module is implemented by using a DDS (direct digital frequency synthesis) technique, and besides this, may be implemented by using a DA (digital to analog conversion) chip.
The program control amplification module adjusts the gain of the module according to different amplitude requirements, the amplitude requirement of the transmitting signal and the instruction of the main control module, and amplifies the transmitting signal by different times. In this embodiment, the programmable amplifying module is implemented by using an amplifier with adjustable gain, such as AD603 and PGA 281. Besides, a multi-way switch can be used for changing the resistance value of the access circuit, or an attenuator such as PE4302 can be used for realizing adjustable gain.
The filtering frequency band of the program-controlled band-pass filtering is set by the main control module according to the frequency of the emission waveform so as to filter the interference of low-frequency noise, higher harmonic and the like generated by the preceding stage. In this embodiment, the programmable bandpass filter uses an analog switch to control the resistance value of the access circuit, so as to adjust the filtering frequency band, such as MAX 4051.
The broadband power amplification module performs power amplification on the waveform by a fixed multiple so as to meet the voltage and power requirements for driving the piezoelectric sensing element. In this embodiment, the class AB power amplifier is designed to improve the load capability of the circuit, and the transformer is used to improve the output voltage value. In addition, high voltage broadband amplifiers, such as PA85, etc., or digital power amplifiers may be used to achieve this function.
The short-circuit protection module automatically protects the short-circuit condition of the piezoelectric sensing element, and can automatically recover to a normal working state after the short-circuit fault is eliminated, so that the system fault caused by the short-circuit can be effectively prevented. In this embodiment, short circuit detection is realized by using a fixed voltage difference between the base and the emitter of the triode, and output level changes of the LED indicator (diode) and the photocoupler are output as an alarm signal.
The impedance matching module is used for carrying out impedance matching on the piezoelectric sensing element so as to reduce energy loss and reduce waveform reflection. In this embodiment, impedance matching as much as possible is achieved over a wide frequency band by using reactance characteristics of a capacitor and an inductor at different frequencies. In addition, proper capacitance and inductance can be connected through a multi-way switch according to the frequency of the transmitted signal, and matching under broadband is achieved.
Since the impedance cannot be perfectly matched at different excitation frequencies, an oscillation cancellation circuit is required to cancel the oscillation generated by the excitation. In this embodiment, the master control module controls the gate of the triac to discharge the oscillation through the optical coupler.
Since a device may have hundreds of piezoelectric sensing elements connected, but only one drive circuit, a selection circuit for transmitting the sensing elements is required to switch the connection of the different sensing elements to the drive circuit. In this embodiment, a multi-channel electronic analog switch is used to implement channel switching, such as MAX 4968. In addition to this, a relay may be used.
The monitoring part of the piezoelectric sensing element consists of functional modules, such as receiving sensing element selection, single-path fast switching, primary signal amplification, multi-stage program control amplification, program control band-pass filtering, fixed gain attenuation, data sampling and the like.
Similar to the transmitting sensing element selection module, one of the receiving sensing elements needs to be selected to be connected with the monitoring part circuit. The implementation of this embodiment is also consistent with the emitting sensing element selection module.
The response signal of the receiving sensor contains crosstalk signals, and the fact that the amplitude of the crosstalk signals is too large can cause that the amplification of the later stage only can use lower gain, and the identification precision of damage is influenced, so that the single-path fast switch is used for removing the crosstalk signals. In this embodiment, the implementation is performed by using a single-channel fast analog switch, such as MAX 4597.
The amplitude of the response signal is weak and needs to be amplified by a first fixed factor. In this embodiment, a high-precision operational amplifier such as OPA392 is used.
The multistage program control amplification uses multistage gain adjustable operational amplifier cascade connection, the gain of each stage of operational amplifier is determined by the main control module according to the size of an actual signal, and finally the amplitude value of the amplified response signal is adjusted to a proper range. In this embodiment, a cascade implementation of gain-adjustable amplifiers, such as AD603 and PGA281, is used. Besides, a multi-way switch can be used for changing the resistance value of the access circuit, or an attenuator such as PE4302 can be used for realizing adjustable gain.
The amplified response signal is sampled by the main control module after band-pass filtering, and the range of the filtering frequency band is determined by the main control module according to the frequency of the transmitted signal so as to filter the interference of other frequency bands in the response signal. In this embodiment, the programmable bandpass filter uses an analog switch to control the resistance value of the access circuit, so as to adjust the filtering frequency band, such as MAX 4051.
In addition, in order to ensure the stability of the transmission signal, the monitoring circuit part can also perform attenuation sampling on the transmission signal.
And respectively sampling the response signal and the transmitting signal by using a high-speed sampling module. In this embodiment, two single-channel analog-to-digital conversion chips are used, such as AD 9649. Besides, the method can be realized by using a multi-channel analog-to-digital conversion chip.
The temperature detection part uses a driving module to increase the driving capability of the temperature sensing element so as to meet the requirement of a long line, and also needs to use a temperature channel selection module to select the connection of the temperature sensing element. The temperature sensing element may be selected and used in a suitable form according to the type of the temperature sensing element. In this embodiment, the temperature sensing element uses a digital temperature sensor with an IIC interface, and a four-channel IIC chip TCA9546 is selected to realize the detection of the multiple temperature sensing elements. In addition to this, an analog temperature sensor may also be used.
And a strain detection section, similar to the temperature detection section, for increasing a driving capability of the strain sensing element using the driving module to satisfy a demand for a long line. It is also desirable to use a strain channel selection module to select the connections of the strain sensing elements. In this embodiment, the strain sensing element uses a resistance-type strain gauge, and strain detection is realized by detecting a resistance value change.
To reduce the number of circuits, the drive circuit, the monitoring circuit, the temperature sensing circuit, and the strain sensing circuit all use a sensing element selection module to connect the appropriate transmitting sensing element, receiving sensing element, temperature sensing element, and strain sensing element. In addition, a plurality of driving circuits can be used to connect with the emission sensing element in a one-to-one manner, and the monitoring circuit, the temperature detection circuit and the strain detection circuit are similar to each other.
Example 2:
the electrical signal input terminal Vin passes through the fifth resistor R5 and the signal output terminal VOUTConnected, signal output terminal VOUTThe signal input end of the piezoelectric sensing element is respectively connected with the first end of a fourth resistor R4 and the collector of a first triode Q1, the emitter of the first triode Q1 is respectively connected with the first end of a first resistor R1 and the first end of a second resistor R2, and the second end of the second resistor R2 is connected with the base of a second triode Q2;
a second end of the fourth resistor R4 is connected with a base of the first triode Q1 and a collector of the second triode Q2, respectively, a first diode D1 is connected between a second end of the fourth resistor R4 and a collector of the second triode Q2, an emitter of the second triode Q2 is connected with a first end of the optocoupler U1, and a second end of the first resistor R1 is connected with a second end of the optocoupler U1, a signal acquisition end, a first end of the sixth resistor R6 and a collector of the fourth triode Q4, respectively;
the signal input end is sequentially connected with the cathode end of the second diode D2 and the first end of the eighth resistor R8, the anode end of the second diode D2 is connected with the emitter of the third triode Q3, the second end of the eighth resistor R8 is connected with the base of the third triode Q3 through the seventh resistor R7, the second end of the eighth resistor R8 is connected with the emitter of the fourth triode Q4, and the collector of the third triode Q3 is connected with the second end of the sixth resistor R6 and the base of the fourth triode Q4 through the third diode D3.
The signal input end is connected with a first end of a first capacitor C1, a second end of a first capacitor C1 is used for being connected with a Lamb wave signal source P1, and the Lamb wave signal source P1 is grounded.
The third end of the optical coupler U1 is connected with a first power supply VCC through a third resistor R3, and the fourth end of the optical coupler U1 is connected with a signal ground.
A second end of the fourth resistor R4 is connected to a positive end of the first diode D1, a negative end of the first diode D1 is connected to a collector of the second transistor D2, a collector of the third transistor Q3 is connected to a negative end of the third diode D3, and a positive end of the third diode D3 is connected to a second end of the sixth resistor R6 and a base of the fourth transistor Q4, respectively.
Because the indicator light D2 and the optocoupler U1 cannot bear high reverse withstand voltage, diodes D1 and D3 which can bear high reverse voltage are added in the schematic diagram, and the D2 and the U1 can not bear high reverse voltage at any time.
The resistor R5 is used for eliminating dead zones caused by the conduction voltages of the Q1 and the Q4. Without R5, the output would remain at 0V when the amplitude of the input signal is less than ± 0.7V, and the addition of R5 may eliminate this dead zone.
When the short circuit takes place for piezoelectric sensing element and when launching drive signal, pilot lamp D2 can be lighted, and the third end level of opto-coupler U1 can be pulled low, is regarded as alarm signal simultaneously, and the circuit is restricted by R1 and R8 to outer output current maximum value, has guaranteed that the instrument can not damaged. When the piezoelectric sensing element is recovered to be normal, the circuit automatically recovers to be normal, and the alarm signal is automatically eliminated.
Example 3:
a Lamb wave signal input end Vin is respectively connected with the transmitting piezoelectric sensing element, a third end of a second optocoupler U2 and a first end of a tenth resistor R10; a second end of the tenth resistor R10 is connected to a first end of the first triac T1, a gate of the first triac T1 is connected to a fourth end of the second optocoupler U2 and a first end of the ninth resistor R9, and a pin 3 of the first triac T1 and a second end of the ninth resistor R9 are grounded.
The first end of the second optical coupler is connected with a pulse input signal Vpulse, and the second end of the second optical coupler is connected with a signal ground.
When the signal transmission is finished, the pulse input signal is utilized to control the conduction of the bidirectional thyristor, and the discharge of the oscillation energy is realized.
Fig. 4 is a diagram illustrating the effect of the oscillation elimination module, where a curve a is a transmitted signal with oscillation, and a curve B is a transmitted signal after the oscillation elimination module is used, and the oscillation signal is effectively eliminated.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The utility model provides a piezoelectricity supersound guided wave detection device which characterized in that:
the method comprises the following steps: the system comprises a main control module, a driving circuit module, a monitoring circuit module, a temperature detection module, a strain detection module, at least two piezoelectric sensing elements, at least one temperature sensing element and at least one strain detection element;
the main control module is connected with at least one first piezoelectric sensing element through the driving circuit module, and at least one second piezoelectric sensing element is connected with the main control module through the monitoring circuit module;
the main control module is connected with at least one temperature sensing element through a temperature detection module;
the main control module is connected with at least one strain sensing element through a strain detection module;
the main control module is used for judging the structural defects by combining the temperature and strain information of the structure according to the received response signals of the second piezoelectric sensing element.
2. The piezoelectric ultrasonic guided wave detection device according to claim 1, wherein:
the driving circuit module comprises an arbitrary waveform generation module, a program-controlled amplification module, a program-controlled band-pass filtering module, a power amplification module, a short circuit protection module, an impedance matching module, a vibration elimination module and a piezoelectric sensing element selection module which are sequentially connected.
3. The piezoelectric ultrasonic guided wave detection device according to claim 2, wherein:
and the arbitrary waveform generation module adjusts parameters of output waveforms according to the requirements of the transmission signals and the instructions of the main control module, and generates driving waveforms with specific amplitudes, frequencies and phases.
4. The piezoelectric ultrasonic guided wave detection device according to claim 2, wherein:
and the program control amplification module adjusts the gain of the module according to the amplitude requirement of the transmitting signal and the instruction of the main control module, and amplifies the transmitting signal by different times.
Or,
the program control band-pass filtering module is used for configuring a filtering frequency band according to the frequency of the transmitting signal and the instruction of the main control module and filtering low-frequency and high-frequency noise generated by a preceding stage;
or,
the broadband power amplification module is used for carrying out power amplification of fixed times on the transmitting signal and improving the output voltage and the driving capability;
or,
the short circuit protection module is used for building a self-recoverable bidirectional short circuit protection circuit by utilizing a triode and is used for overcurrent protection during short circuit of the first piezoelectric sensing element;
or,
the impedance matching module is used for building a matching circuit by using a resistor, a capacitor and an inductor, so that the matching of the output impedance of the device and the impedance of the piezoelectric sensing element is realized, and the energy loss of a transmitting signal is reduced;
or,
the oscillation elimination module utilizes the main control module to control the on-off of the bidirectional thyristor so as to eliminate the oscillation of the transmitted signal;
or,
and the transmitting sensing element selection module is used for selecting at least one piezoelectric sensing element from the plurality of piezoelectric sensing elements as a first piezoelectric sensing element for transmitting.
5. The piezoelectric ultrasonic guided wave detection device according to claim 1, wherein:
the monitoring circuit module comprises a piezoelectric sensing element selection module, a single-path speed switch module, a primary amplification module, a multi-stage program control amplification module, a program control band-pass filtering module, a fixed gain attenuation module and a data sampling module which are sequentially connected.
6. The piezoelectric ultrasonic guided wave detection device according to claim 5, wherein:
and the receiving piezoelectric sensing element selection module is used for selecting at least one piezoelectric sensing element from the plurality of piezoelectric sensing elements as a second piezoelectric sensing element for receiving.
7. The piezoelectric ultrasonic guided wave detection device according to claim 5, wherein:
the single-path fast switch module is opened before the excitation signal is ended and closed after the excitation signal is ended, is used for eliminating crosstalk signals in the response signal, and is controlled by the instruction of the main control module to be opened and closed;
or,
and the primary signal amplification module adopts precise operational amplifier to carry out primary amplification of fixed times on the response signal.
Or,
the multi-stage program control amplification module is realized by adopting a plurality of operational amplifiers with adjustable gains in a cascade mode, and the gain of each operational amplifier is configured according to the instruction of the main control module;
or,
the program control band-pass filtering module is used for configuring a filtering frequency band according to the frequency of the transmitting signal and the instruction of the main control module and filtering low-frequency and high-frequency noises in the response signal;
or,
the fixed gain attenuation module is used for carrying out fixed gain amplitude attenuation on the transmitting signal without changing the frequency and the phase of the transmitting signal;
or,
and the high-speed data sampling module is used for carrying out analog-to-digital conversion on the attenuated transmitting signal and the amplified response signal.
8. The piezoelectric ultrasonic guided wave detection device according to claim 1, wherein:
the main control module is connected with the temperature sensing elements through the temperature detection module, and the main control module is used for selectively connecting the plurality of temperature sensing elements through the temperature channel selection module.
9. The piezoelectric ultrasonic guided wave detection device according to claim 1, wherein:
the main control module is connected with the strain sensing elements through the strain detection module, and the main control module is used for selectively connecting the plurality of strain sensing elements through the strain channel selection module.
10. A piezoelectric ultrasonic guided wave detection method, which is characterized by using the piezoelectric ultrasonic guided wave detection device of any one of claims 1 to 9, and comprises the following processes:
the piezoelectric sensing elements, the temperature sensing element and the strain sensing element are arranged on the structure body to be measured;
the main control module drives a certain first piezoelectric sensing element to transmit a preset waveform signal by using the driving circuit module, the frequency and the phase of the transmitted signal are adjusted by the arbitrary waveform generation module, and the amplitude of the transmitted signal is adjusted by the arbitrary waveform transmission module and the program control amplification module together;
the main control module filters noise of other frequency bands in the transmitting signal by utilizing an adjustable band-pass filtering module according to the frequency of the transmitting signal;
the main control module controls the oscillation eliminating module to eliminate oscillation of the transmitted waveform according to the end time of the transmitted signal;
the main control module controls the transmitting sensing element selection module, and selects at least one first piezoelectric sensing element for transmitting from the plurality of piezoelectric sensing elements;
the main control module receives a response signal of a certain second piezoelectric sensing element by using the monitoring circuit module;
the main control module controls the receiving sensing element selection module to select at least one second piezoelectric sensing element for receiving from the plurality of piezoelectric sensing elements;
the main control module controls the action of the single-path fast switch according to the end time of the law case emission signal, and eliminates the crosstalk influence in the response signal;
the main control module adaptively adjusts the gain of the multi-stage programmable control amplification module according to the amplitude of the response signal;
the main control module filters noise of other frequency bands in the response signal by using an adjustable band-pass filtering module according to the frequency of the transmission signal;
the main control module samples the attenuated transmitting signal and the amplified response signal by using a high-speed data sampling module;
the main control module receives structural temperature information acquired by a certain temperature sensing element by using the temperature detection module, controls the temperature channel selection module, selects at least one of the temperature sensing elements as the temperature sensing element and acquires the structural temperature information;
the main control module receives structural strain information acquired by a certain strain sensing element by using the strain detection module, controls the strain channel selection module, selects at least one strain sensing element from the plurality of strain sensing elements as the strain sensing element, and acquires the structural strain information;
the main control module judges the structural damage according to the change of the response signal received by the second piezoelectric sensing element and by combining the temperature information and the strain information of the structure.
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