CN108195884A - A kind of lossless detection method and system based on current vortex pulse thermal imaging - Google Patents
A kind of lossless detection method and system based on current vortex pulse thermal imaging Download PDFInfo
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- CN108195884A CN108195884A CN201810031692.4A CN201810031692A CN108195884A CN 108195884 A CN108195884 A CN 108195884A CN 201810031692 A CN201810031692 A CN 201810031692A CN 108195884 A CN108195884 A CN 108195884A
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Abstract
The embodiment of the present invention discloses a kind of lossless detection method and system based on current vortex pulse thermal imaging, and method includes：Sensing heater is controlled to generate high-frequency alternating current by initial heating pulse signal, provide current vortex excitation with reference to induction coil to heat tested exemplar；The infrared emanation of tested exemplar is measured to obtain the surface heat distribution of tested exemplar, and obtains infrared thermal imaging graphic sequence according to surface heat distribution and is handled, obtains the sample temperature of the predetermined sampled point of tested exemplar；If the sample temperature is not less than pre-set non-destructive testing high temperature threshold value, is exported to impulse generator and stop heating instructions, if the sample temperature is not more than pre-set non-destructive testing low temperature threshold, exported to impulse generator and start heating instructions；According to heating instructions control sensing heater deenergization is stopped, heater starting power supply is answered to generate high-frequency alternating current according to heating instructions Perceived control.With the application of the invention, the temperature control precision of heating can be promoted.
Description
Technical field
The present invention relates to non-destructive testing technology more particularly to a kind of lossless detection methods based on current vortex pulse thermal imaging
And system.
Background technology
Non-destructive testing is to ensure the key technology of Important Project equipment manufacturing quality and operational safety, based on current vortex pulse
The non-destructive testing technology integrated use of thermal imaging current vortex and joule thermal phenomenon, have that non-contact, single area of detection is big, effect
The high advantage of rate, can effectively detect surface defect, provide safeguard for quality and operational safety, be field of non destructive testing in recent years
Research hotspot.
At present, current vortex pulse thermal imaging is mainly based upon defect to the assessment of surface defect and current vortex distribution is disturbed
It is dynamic.For being tested the crackle of sample surface or inside, due to being mainly air among crackle, it is infinite that can be approximately considered impedance
Greatly, according to Ohm's law, the path of impedance minimum by current vortex it is maximum, thus, when current vortex encounters in flow process
When tested sample surface or the slit of inside, for flowing through the current vortex of slit side, via slit endpoint and Slot bottom
Shortest path, impedance is minimum, and therefore, current vortex separates to both sides and passes through slit endpoint, alternatively, bypass slit from bottom,
In turn resulting in slit side and top electric eddy current density reduces, and at endpoint and bottom electric eddy current density increases.Determined by joule
Rule it is found that heating power and electric eddy current density it is square directly proportional, thus, low-temperature region is formed in slit both sides and top,
High-temperature area is formed in the bottom portion of groove of both ends and defect.Heating power differs caused by this difference as vortex density
It causes, causes the imbalance of tested exemplar material internal heat distribution, when heat is transmitted to material surface, make tested sample surface
The phenomenon that uneven in temperature is presented in Temperature Distribution, so as to provide foundation for defects detection.
Fig. 1 is the existing nondestructive detection system structure diagram based on current vortex pulse thermal imaging.Referring to Fig. 1, the system
Including：Sensing heater, thermal infrared imager, processor, impulse generator and induction coil, wherein,
Under the pulse signal control that sensing heater is exported in impulse generator, high-frequency alternating current is generated, and pass through sensing
Coil provides current vortex excitation, to heat tested exemplar；
Under the synchronization pulse control that thermal infrared imager is exported in impulse generator, the infrared hot spoke of tested exemplar is measured
The surface heat distribution to obtain tested exemplar is penetrated, and is imaged according to surface heat distribution, obtains infrared thermal imaging graphic sequence, it is defeated
Go out to processor；
Processor handles the infrared thermal imaging graphic sequence received, obtains the surface defect information of tested exemplar,
And show the Infrared Thermogram of tested exemplar.
Impulse generator exports the pulse signal of fixed duty cycle, to synchronous triggering sensing heater and infrared thermal imagery
Instrument is allowed to work in the case where pulse signal controls, and the duty ratio of pulse signal is by the predetermined heating time to being tested exemplar
It is determined with cooling time.
But in the current non-destructive testing based on current vortex pulse thermal imaging, according to preset pulse signal to tested
Exemplar carries out computer heating control, and the temperature control precision of heating is poor, be easy to cause the scaling loss of tested exemplar；Simultaneously as using
The natural type of cooling so that will appear the otherness of test result at different ambient temperatures so that non-destructive testing is easily by ring
The influence of border temperature.
Invention content
In view of this, the embodiment of the present invention provides a kind of lossless detection method based on current vortex pulse thermal imaging and is
System can promote the temperature control precision of heating, the scaling loss probability for reducing tested exemplar.
In a first aspect, the embodiment of the present invention provides a kind of nondestructive detection system based on current vortex pulse thermal imaging, including：
Sensing heater, thermal infrared imager, processor, impulse generator, induction coil and sample temperature controller, wherein,
Under initial heating pulse signal and the heating pulse signal control that sensing heater is exported in impulse generator, production
Raw high-frequency alternating current, and provide current vortex by induction coil and encourage, to heat tested exemplar；In stopping for impulse generator output
Only under heating pulse signal control, power cutoff；
Under the initial heating pulse signal control that thermal infrared imager is exported in impulse generator, the infrared of tested exemplar is measured
Heat radiation is imaged with obtaining the surface heat distribution of tested exemplar according to surface heat distribution, obtains infrared thermal imaging figure sequence
Row, export to processor；
Processor handles the infrared thermal imaging graphic sequence received, obtains the surface defect information of tested exemplar,
And show the infrared thermal imaging of tested exemplar；
Sample temperature controller, for from the infrared thermal imaging graphic sequence, obtaining the predetermined sampled point of tested exemplar
Sample temperature, if the sample temperature be not less than pre-set non-destructive testing high temperature threshold value, to impulse generator export
Stop heating instructions, it is defeated to impulse generator if the sample temperature is not more than pre-set non-destructive testing low temperature threshold
Go out to start heating instructions；
Impulse generator, after initial start, output initial heating pulse signal is with synchronous triggering sensing heater and red
Outer thermal imager operation after stopping heating instructions being received, exports to sensing heater and stops heating pulse signal, receiving
After heating instructions, heating pulse signal is exported to sensing heater.
Preferably, the quantity of the sampled point is one or more, if the quantity of sampled point is multiple, sample temperature is
The temperature change mean value of multiple sampled points.
Preferably, it is sampled point to choose the high corresponding point of tested exemplar electric eddy current density or region.
Preferably, the non-destructive testing low temperature threshold is higher than environment temperature.
Preferably, the temperature difference of the non-destructive testing high temperature threshold value and tested exemplar scaling loss temperature is more than a constant value.
Second aspect, the embodiment of the present invention provide a kind of lossless detection method based on current vortex pulse thermal imaging, including：
By initial heating pulse signal control sensing heater generate high-frequency alternating current, with reference to induction coil provide current vortex excitation with
The tested exemplar of heating；
The infrared emanation of tested exemplar is measured to obtain the surface heat distribution of tested exemplar, and according to surface heat distribution into
Row imaging, obtains infrared thermal imaging graphic sequence；
Infrared thermal imaging graphic sequence is handled, obtains the sample temperature of the predetermined sampled point of tested exemplar；
If the sample temperature is not less than pre-set non-destructive testing high temperature threshold value, exports and stop to impulse generator
Heating instructions if the sample temperature is not more than pre-set non-destructive testing low temperature threshold, are opened to impulse generator output
Dynamic heating instructions；
According to heating instructions control sensing heater deenergization is stopped, heater starting is answered according to heating instructions Perceived control
Power supply generates high-frequency alternating current.
Preferably, the method can also include：
According to the infrared thermal imaging graphic sequence of processing, the surface defect information of tested exemplar is obtained, and shows tested exemplar
Infrared thermal imaging.
Preferably, the quantity of the sampled point is one or more, if the quantity of sampled point is multiple, sample temperature is
The temperature change mean value of multiple sampled points.
Preferably, it is sampled point to choose the high corresponding point of tested exemplar electric eddy current density or region.
Preferably, the non-destructive testing low temperature threshold is higher than environment temperature, the non-destructive testing high temperature threshold value and detected sample
The temperature difference of part scaling loss temperature is more than a constant value.
A kind of lossless detection method and system based on current vortex pulse thermal imaging provided in an embodiment of the present invention, by first
Beginning heating pulse signal control sensing heater generates high-frequency alternating current, provides current vortex excitation with reference to induction coil to heat quilt
Test sample part；The infrared emanation of tested exemplar is measured to obtain the surface heat distribution of tested exemplar, and according to surface heat distribution into
Row imaging, obtains infrared thermal imaging graphic sequence；Infrared thermal imaging graphic sequence is handled, obtains the predetermined sampling of tested exemplar
The sample temperature of point；If the sample temperature is not less than pre-set non-destructive testing high temperature threshold value, defeated to impulse generator
Go out to stop heating instructions, if the sample temperature is not more than pre-set non-destructive testing low temperature threshold, to impulse generator
Output starts heating instructions；It, should according to heating instructions Perceived control according to heating instructions control sensing heater deenergization is stopped
Heater starting power supply generates high-frequency alternating current, in this way, exporting infrared thermal imaging graphic sequence by extract real-time infrared thermoviewer
In pre-set sampling area temperature sampling value, be compared with pre-set non-destructive testing temperature threshold, according to than
Relatively result controls PULSE HEATING process and temperature-fall period, make tested exemplar heating maximum temperature and cooling it is minimum
Temperature is kept constant, and can promote the temperature control precision of heating, the scaling loss probability for reducing tested exemplar.
Description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, to embodiment or will show below
There is attached drawing needed in technology description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention, for those of ordinary skill in the art, without creative efforts, can be with
Other attached drawings are obtained according to these attached drawings.
Fig. 1 is the existing nondestructive detection system structure diagram based on current vortex pulse thermal imaging；
Fig. 2 is nondestructive detection system structure diagram of the embodiment of the present invention one based on current vortex pulse thermal imaging；
Fig. 3 is the sample temperature change curve schematic diagram of the present embodiment；
Fig. 4 is lossless detection method flow diagram of the embodiment of the present invention two based on current vortex pulse thermal imaging.
Specific embodiment
The embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.
It will be appreciated that described embodiment is only part of the embodiment of the present invention, instead of all the embodiments.Base
Embodiment in the present invention, those of ordinary skill in the art obtained without creative efforts it is all its
Its embodiment, shall fall within the protection scope of the present invention.
Infrared thermal imaging graphic sequence change with time rule include two stages：The zooming sensing of material temperature adds
The cooling stage that hot stage and material temperature continuously decrease.Wherein, in the sensing heating stage, when being tested the temperature of exemplar with heating
Between rise, in the phase diagram formed by infrared thermal imaging graphic sequence, defect area (Nonuniform Domain Simulation of Reservoir) and non-defective region are (uniformly
Region) phase difference it is smaller, and show larger phase difference in cooling stage, defect area and non-defective region.
Existing nondestructive detection system, non-destructive testing mode be open loop, i.e., sensing heater, thermal infrared imager, processor,
Impulse generator and induction coil form an open cycle system.Under open loop condition, in the acquisition of infrared thermal imaging graphic sequence
Cheng Zhong does not feed back tested exemplar temperature change, and heating process easily forms temperature and is gradually increasing, due to temperature by
Gradually rise, when detecting between it is longer when be easy to cause tested exemplar and be chronically at hot environment, so as to cause to being tested exemplar
The damages such as ablation, meanwhile, it is tested exemplar temperature or environment temperature rises or variation, will also cause range of temperature relatively low,
Show as that amplitude difference is smaller in map of magnitudes, so as to reduce the amplitude resolution of non-destructive testing process.
Fig. 2 is nondestructive detection system structure diagram of the embodiment of the present invention one based on current vortex pulse thermal imaging.Ginseng
See Fig. 2, the nondestructive detection system of the embodiment of the present invention includes：Sensing heater, thermal infrared imager, processor, impulse generator,
Induction coil and sample temperature controller, wherein,
Under initial heating pulse signal and the heating pulse signal control that sensing heater is exported in impulse generator, production
Raw high-frequency alternating current, and provide current vortex by induction coil and encourage, to heat tested exemplar；In stopping for impulse generator output
Only under heating pulse signal control, power cutoff；
Under the initial heating pulse signal control that thermal infrared imager is exported in impulse generator, the infrared of tested exemplar is measured
Heat radiation is imaged with obtaining the surface heat distribution of tested exemplar according to surface heat distribution, obtains infrared thermal imaging figure sequence
Row, export to processor；
Processor handles the infrared thermal imaging graphic sequence received, obtains the surface defect information of tested exemplar,
And show the infrared thermal imaging of tested exemplar；
In the present embodiment, processor mainly wraps the processing of high speed infrared thermograph sequence that thermal infrared imager obtains
It includes：The enhancing and extraction of tested exemplar defect information.In current vortex thermal imaging, the defects of current vortex is directly with surface and shallow-layer
It interacts, high temperature and low-temperature region is generated around defect, and then depositing for defect is disclosed according to high temperature and low-temperature region
Whether.
Three-dimensional matrice of the infrared thermal imaging graphic sequence of thermal infrared imager record for a pixel point coordinates and pixel frame number, often
One pixel is identified using pixel point coordinates, and each pixel (permutation matrix for forming M × N) in same plane forms one
Frame, i.e., the measured value of each frame form M × N two-dimensional matrix, which is infrared thermal imaging figure.Each pixel
The measured value of (m, n) changes with time fm,n(p) one-dimensional vector is formed.In actually detected, due to thermal infrared imager with
The relative position of tested exemplar be it is fixed, thus, pixel is corresponded with tested exemplar surface region, pixel it is one-dimensional
Vector can describe material surface corresponding region infra-red radiation and change with time process, referred to as transient state infrared heat response, i.e. wink
State infrared thermal imaging figure changes with time rule.As described above, typical transient state infrared heat response includes two stages：Material
The sensing heating stage that temperature rapid increase and the cooling stage that material temperature continuously decreases.
Known by Fourier transformation basic principle, any signal can be decomposed by Fourier transformation it is a series of sinusoidal and
The superposition of cosine function when signal is the signal changed over time, is fourier transformed the spectrum component that signal can be obtained.This
In embodiment, in current vortex pulse thermal imaging, since detection time is limited, transient state infrared heat response fm,n(p) to there is limit for length real
Number Sequence, by discrete Fourier transform, can acquire its signal at frequencies omega is：
Wherein,
ω=1,2,3 ..., P-1；
P is sampling number；
NpFor frame number；
Rm,n(ω) and Im,n(ω) is respectively Fm,nThe real and imaginary parts of (ω)；
F is calculated using following formulam,nThe amplitude and phase of (ω)：
It asks for the amplitude and phase at frequencies omega respectively to each pixel, obtains the infrared heat of the corresponding transient state of a frame and ring
The magnitude image of induction signal | F (ω) | and phase image | φ (ω) |.
Since pulse eddy current driving source is mechanical periodicity, in amplitude after the conversion, phase diagram, crackle both ends are in width
Be shown as highlight regions on degree figure, disclose defect presence and can quick positioning defect areas, by being carried out to tested exemplar
Spectrum analysis can effectively carry out defects detection.
Phase diagram describes pixel infrared heat response and changes with time rule, and the changing rule and amplitude without
It closes, in rapid heat-up stage, phase diagram, defect area and the phase difference in non-defective region are smaller, and in cooling stage, phase
The defects of bitmap region shows larger phase difference with non-defective region.Thus, in non-destructive testing, select larger
High and low temperature difference and appropriate heating cycle are conducive to improve pulsed infrared thermal imaging nondestructive detection system performance.
Sample temperature controller, for from the infrared thermal imaging graphic sequence, obtaining the predetermined sampled point of tested exemplar
Sample temperature, if the sample temperature be not less than pre-set non-destructive testing high temperature threshold value, to impulse generator export
Stop heating instructions, it is defeated to impulse generator if the sample temperature is not more than pre-set non-destructive testing low temperature threshold
Go out to start heating instructions；
In the present embodiment, as an alternative embodiment, sample temperature controller can also be from the infrared thermal imaging of processor
The sample temperature of the middle predetermined sampled point for obtaining tested exemplar.
In the present embodiment, as an alternative embodiment, processor and sample temperature controller two in computer in order to control
The infrared thermal imaging graphic sequence of acquisition is output to control computer, and obtained in real time by the storage of control computer by unit, thermal infrared imager
The infrared thermal imaging graphic sequence taken, can quick obtaining sampling by analyzing each frame infrared thermal imaging graphic sequence obtained in real time
The range value of point, which is directly linked the temperature changing process of tested exemplar, so as to can obtain the real-time temperature of detected sample part
Change curve is spent in order to be controlled into trip temperature.
In the present embodiment, during control, obtained sample temperature change curve will be sampled as current vortex pulse
Signal is controlled, the corresponding sample temperature of real time temperature change curve with non-destructive testing temperature threshold is compared, works as sampled point
Sample temperature when being greater than or equal to non-destructive testing high temperature threshold value, (current vortex heats output control signal-off sensing heater
Device), exemplar is made to stop heating, when probe temperature is less than non-destructive testing low temperature threshold, then control signal unlatching sensing is exported and adds
Hot device is to heat exemplar.
In the present embodiment, the quantity of sampled point can be one or more, if the quantity of sampled point is 1, sampled point is anti-
Single point temperature variation is presented, if the quantity of sampled point is multiple (for example, sampling areas), sample temperature is the temperature of multiple sampled points
Spend change mean.
In the present embodiment, as an alternative embodiment, the high corresponding point of the tested exemplar electric eddy current density of setting or region are
Sampled point thereby may be ensured that the highest temperature zone of tested exemplar within the temperature range of control, i.e., no more than non-destructive testing height
Warm threshold value.Certainly, in practical application, as another alternative embodiment, sampled point can also be arranged on other areas of tested exemplar
Domain, and according to the non-destructive testing high temperature threshold in the region region corresponding with highest temperature zone and tested exemplar scaling loss temperature setting
Value.
Fig. 3 is the sample temperature change curve schematic diagram of the present embodiment.As shown in figure 3, in the present embodiment, horizontal axis for heat into
As graphic sequence, corresponding to time of the tested exemplar during non-destructive testing, the longitudinal axis for sampled point sample temperature (sampled point/
Area sampling value), wherein,
Tr0For be tested exemplar from room temperature non-destructive testing high temperature threshold value is heated to by current vortex when temperature ramp de, should
Process is the initial temperature-rise period of tested exemplar, that is, is preheated；
Tested exemplar stops current vortex heating, makes after room temperature is warming up to high-temperature control point (non-destructive testing high temperature threshold value)
Tested exemplar enters cooling stage, after it reaches low temperature control point (non-destructive testing low temperature threshold), again to tested exemplar into
Row eddy heating for heating, TrEnter the heating point (non-destructive testing low temperature threshold) in formal non-destructive testing stage for exemplar, from after the moment,
The temperature change of tested exemplar enters relatively stable cyclically-varying stage, period T；
The heating-up time of tested exemplar point from low temperature control point to high-temperature control heats pulse width time (heating arteries and veins for current vortex
It is wide), and stop heating pulse width time, high-temperature control for current vortex from high-temperature control point to the Wen Duxiajiang times at low temperature control point
Point and temperature spot centered on the mean value at low temperature control point.
In the present embodiment, during current vortex PULSE HEATING, when the sample temperature value of sampled point reaches the lossless of setting
After detecting high temperature threshold value, stop current vortex heating, tested exemplar is made to be transferred to cooling procedure, when sample temperature value drops to setting
During non-destructive testing low temperature threshold, current vortex heating is started again at, until the non-destructive testing high temperature threshold value of setting, so as to utilize
The non-destructive testing high temperature threshold value of setting and non-destructive testing low temperature threshold carry out periodic heat and cooling to tested exemplar.
In the present embodiment, as an alternative embodiment, in order to reduce environment temperature to being tested exemplar non-destructive testing process
It influences, non-destructive testing low temperature threshold is normally set up higher than environment temperature, and the difference of non-destructive testing low temperature threshold and environment temperature is big
In or equal to pre-set temperature difference threshold, so as to be conducive to reduce tested exemplar in cooling procedure by the shadow of environment temperature
It rings, while can also shorten tested exemplar and be cooled to time needed for non-destructive testing low temperature threshold, reduce the whole nothing of tested exemplar
Damage detection time.
In the present embodiment, as an alternative embodiment, the temperature value setting (non-destructive testing high temperature threshold value) of high-temperature control point
It can specifically be set according to tested sample material so that non-destructive testing high temperature threshold value is less than tested exemplar scaling loss temperature, alternatively,
Non-destructive testing high temperature threshold value and the temperature difference of tested exemplar scaling loss temperature are more than a constant value.For example, when tested exemplar is easily in height
When being damaged under the conditions of temperature or performance change occurs, non-destructive testing high temperature threshold value can be reduced, so as to ensure that tested exemplar was detecting
It will not be damaged in journey.
Impulse generator, after initial start, output initial heating pulse signal is with synchronous triggering sensing heater and red
Outer thermal imager operation after stopping heating instructions being received, exports to sensing heater and stops heating pulse signal, receiving
After heating instructions, heating pulse signal is exported to sensing heater.
In the present embodiment, as an alternative embodiment, impulse generator can also be defeated according to pre-set dutyfactor value
Go out pulse signal, after stopping heating instructions being received, adjust the duty ratio of pulse signal, use the pulse signal currently exported
Stop heating in instruction sensing heater, after heating instructions are received, adjust the duty ratio of pulse signal, make what is currently exported
Pulse signal is used to indicate sensing heater heating.
In the present embodiment, sampled point temperature change is monitored using close-loop control mode, under the conditions of closed-loop control, sampling temperature
Degree controller can be also used for before being carried out non-destructive testing to tested exemplar, according to the infrared thermal imaging that processor is shown, selection
The big region of electric eddy current density or point are as sampled point.So as to during entire non-destructive testing, obtain tested exemplar sampled point
Sample temperature change curve, with reference to preset non-destructive testing temperature threshold (non-destructive testing high temperature threshold value and lossless inspection
Survey low temperature threshold), so as to control the heating time of current vortex pulse signal and cooling time so that the heating temperature of sampled point is not
More than non-destructive testing high temperature threshold value, cooling temperature is not less than non-destructive testing low temperature threshold, so as to ensure tested exemplar temperature whole
During a non-destructive testing, substantially in non-destructive testing low temperature threshold to the temperature setting regions between non-destructive testing high temperature threshold value
Cyclically-varying so as to promote the temperature control precision of heating and cooling, improves while the scaling loss for preventing exemplar
Amplitude resolution in later stage conversion process.
In the present embodiment, pre-set sampling in infrared thermal imaging graphic sequence is exported by extract real-time infrared thermoviewer
The temperature sampling value in region is compared with pre-set non-destructive testing temperature threshold, according to comparison result to PULSE HEATING
Process and temperature-fall period are controlled, and keep constant the maximum temperature of tested exemplar heating and the minimum temperature of cooling, energy
Relatively strong periodically variable infrared image is preferably obtained, while also can improve detected sample on the basis of the temperature sampling signal
Range of temperature in part detection process so that the cyclically-varying process that detection process is low temperature, high temperature dot is basicly stable,
It is not influenced by variation of ambient temperature, and the high/low temperature difference during cyclically-varying can be improved on this basis, so as to carry
The resolution ratio of high-amplitude figure.It has the following advantages that：
(1) by the way that non-destructive testing low temperature threshold is set to be higher than environment temperature so that the central temperature lifting of tested exemplar has
Conducive to reducing variation of ambient temperature to being tested the influence of exemplar and testing result, while central temperature is raised, and is conducive to reduce
Tested exemplar, with the temperature difference of environment temperature, accelerates the temperature drop rate of tested exemplar in temperature-fall period；
(2) about non-destructive testing high temperature threshold value and non-destructive testing low temperature threshold two temperature control point setting, be conducive to
The range of temperature of tested exemplar is improved, improves tested homogeneous zones of the exemplar under the conditions of thermal change and heterogeneity area
The difference in domain；
(3) tested exemplar can be effectively ensured in the non-destructive testing high temperature threshold value of setting will not be damaged during non-destructive testing
Or ablation；
(4) stability for being advantageously selected for improving nondestructive detection system of low temperature control point (non-destructive testing low temperature threshold),
And the variation of environment temperature is influenced smaller；
(5) different tested exemplars can be effectively ensured in the feedback control scheme of the sample temperature real-time change curve of the present embodiment
Variation by a relatively large margin under the conditions of different parameters, is conducive to the detection of the relevant informations such as the phase in later stage；
(6) heating process can compare control under feedback condition by sample temperature change curve and temperature-fall period, from
And slow down heating process, make heating process that there is preferable symmetry with the temperature-fall period time, while can also reduce heated
The maximum drive current that system needs in journey.
Fig. 4 is lossless detection method flow diagram of the embodiment of the present invention two based on current vortex pulse thermal imaging.Such as
Shown in Fig. 4, which includes：
Step 401, sensing heater is controlled to generate high-frequency alternating current by initial heating pulse signal, with reference to induction coil
Current vortex excitation is provided to heat tested exemplar；
Step 402, the infrared emanation of tested exemplar is measured to obtain the surface heat distribution of tested exemplar, and according to surface
Heat distribution is imaged, and obtains infrared thermal imaging graphic sequence；
Step 403, infrared thermal imaging graphic sequence is handled, obtains the sampling temperature of the predetermined sampled point of tested exemplar
Degree；
Step 404, if the sample temperature is not less than pre-set non-destructive testing high temperature threshold value, to impulse generator
Output stops heating instructions, if the sample temperature is not more than pre-set non-destructive testing low temperature threshold, to pulse generation
Device output starts heating instructions；
Step 405, according to heating instructions control sensing heater deenergization is stopped, should adding according to heating instructions Perceived control
Hot device startup power supply generates high-frequency alternating current.
In the present embodiment, as an alternative embodiment, this method further includes：
According to the infrared thermal imaging graphic sequence of processing, the surface defect information of tested exemplar is obtained, and shows tested exemplar
Infrared thermal imaging.
In the present embodiment, infrared thermal imaging graphic sequence is handled, the surface defect information of tested exemplar can be obtained,
And the infrared thermal imaging of tested exemplar can be shown over the display, in order to intuitively understand the specific defect of tested exemplar letter
Breath, for example, defect size, defective locations, defect shape, defect Temperature Distribution etc..
In the present embodiment, the infrared thermal imaging graphic sequence of thermal infrared imager record is a pixel point coordinates and pixel frame number
Three-dimensional matrice, each pixel are identified using pixel point coordinates, and each pixel in same plane forms a frame, each pixel
The measured value of point, which changes with time, forms an one-dimensional vector.Since the relative position of thermal infrared imager and tested exemplar is solid
Fixed, thus, pixel is corresponded with tested exemplar surface region, and the one-dimensional vector of pixel can describe material surface pair
Region infra-red radiation is answered to change with time process, spectrum analysis is carried out using Fourier transformation, each pixel can be asked for
Magnitude image and phase image of the point at any frequency, by magnitude image and phase image, can carry out defects detection and
Positioning.
In the present embodiment, initial heating pulse signal and heating pulse letter that sensing heater is exported in impulse generator
Number control under, generate high-frequency alternating current, and by induction coil provide current vortex encourage, to heat tested exemplar；It is sent out in pulse
Under the stopping heating pulse signal control of raw device output, power cutoff；
Under the initial heating pulse signal control that thermal infrared imager is exported in impulse generator, the infrared of tested exemplar is measured
Heat radiation is imaged with obtaining the surface heat distribution of tested exemplar according to surface heat distribution, obtains infrared thermal imaging figure sequence
Row, export to processor；
Processor handles the infrared thermal imaging graphic sequence received, obtains the surface defect information of tested exemplar,
And show the infrared thermal imaging of tested exemplar；
Sample temperature controller, for from the infrared thermal imaging graphic sequence, obtaining the predetermined sampled point of tested exemplar
Sample temperature, if the sample temperature be not less than pre-set non-destructive testing high temperature threshold value, to impulse generator export
Stop heating instructions, it is defeated to impulse generator if the sample temperature is not more than pre-set non-destructive testing low temperature threshold
Go out to start heating instructions；
Impulse generator, after initial start, output initial heating pulse signal is with synchronous triggering sensing heater and red
Outer thermal imager operation after stopping heating instructions being received, exports to sensing heater and stops heating pulse signal, receiving
After heating instructions, heating pulse signal is exported to sensing heater.
In the present embodiment, as an alternative embodiment, the quantity of the sampled point is one or more, if sampled point
Quantity is multiple, and sample temperature is the temperature change mean value of multiple sampled points.
In the present embodiment, as an alternative embodiment, choose the high corresponding point of tested exemplar electric eddy current density or region is
Sampled point is to ensure the highest temperature zone of tested exemplar within the temperature range of control.
In the present embodiment, as an alternative embodiment, in order to reduce environment temperature to being tested exemplar non-destructive testing process
It influences, the non-destructive testing low temperature threshold of selection is higher than environment temperature；Alternatively, the difference of non-destructive testing low temperature threshold and environment temperature
More than or equal to pre-set temperature difference threshold.
In the present embodiment, as an alternative embodiment, non-destructive testing high temperature threshold value can be according to the tested sample material point of difference
It is not set specifically, non-destructive testing high temperature threshold value and the temperature difference of tested exemplar scaling loss temperature are more than a constant value, to ensure quilt
Test sample part will not be damaged in detection process.
It should be noted that herein, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any this practical relationship or sequence.Moreover, term " comprising ", "comprising" or its any other variant are intended to
Non-exclusive inclusion, so that process, method, article or equipment including a series of elements not only will including those
Element, but also including other elements that are not explicitly listed or further include as this process, method, article or equipment
Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
Also there are other identical elements in process, method, article or equipment including the element.
Each embodiment in this specification is described using relevant mode, identical similar portion between each embodiment
Point just to refer each other, and the highlights of each of the examples are difference from other examples.
For system embodiment, since it is substantially similar to embodiment of the method, so the comparison of description is simple
Single, the relevent part can refer to the partial explaination of embodiments of method.
Expression or logic and/or step described otherwise above herein in flow charts, for example, being considered use
In the order list for the executable instruction for realizing logic function, may be embodied in any computer-readable medium, for
Instruction execution system, system or equipment (such as computer based system, including the system of processor or other can be held from instruction
The system of row system, system or equipment instruction fetch and execute instruction) it uses or combines these instruction execution systems, system or set
It is standby and use.For the purpose of this specification, " computer-readable medium " can any can be included, store, communicate, propagate or pass
Defeated program for instruction execution system, system or equipment or with reference to these instruction execution systems, system or equipment and what is used be
System.The more specific example (non-exhaustive list) of computer-readable medium is including following：Electricity with one or more wiring
Connecting portion (electronic system), portable computer diskette box (magnetic system), random access memory (RAM), read-only memory
(ROM), erasable edit read-only storage (EPROM or flash memory), fibre system and portable optic disk is read-only deposits
Reservoir (CDROM).In addition, computer-readable medium can even is that the paper that can print described program on it or other are suitable
Medium, because can be for example by carrying out optical scanner to paper or other media, then into edlin, interpretation or when necessary with it
His suitable method is handled electronically to obtain described program, is then stored in computer storage.
It should be appreciated that each section of the present invention can be realized with hardware, software, firmware or combination thereof.
In the above-described embodiment, multiple steps or method can be with storages in memory and by suitably instructing execution
The software or firmware that system performs are realized.If for example, being realized with hardware in another embodiment, can use
Any one of following technology well known in the art or their combination are realized：With for data-signal realization logic work(
The discrete logic of the logic gates of energy has the application-specific integrated circuit of suitable combinational logic gate circuit, programmable gate
Array (PGA), field programmable gate array (FPGA) etc..
Those skilled in the art are appreciated that realize all or part of step that above-described embodiment method carries
Suddenly it is that relevant hardware can be instructed to complete by program, the program can be stored in a kind of computer-readable storage medium
In matter, the program when being executed, one or a combination set of the step of including embodiment of the method.
For convenience of description, description system above is to be divided into various units/modules with function to describe respectively.Certainly, exist
Implement the function of each unit/module is realized can in the same or multiple software and or hardware during the present invention.
As seen through the above description of the embodiments, those skilled in the art can be understood that the present invention can
It is realized by the mode of software plus required general hardware platform.Based on such understanding, technical scheme of the present invention essence
On the part that the prior art contributes can be embodied in the form of software product in other words, the computer software product
It can be stored in storage medium, such as ROM/RAM, magnetic disc, CD, be used including some instructions so that a computer equipment
(can be personal computer, server either network equipment etc.) performs the certain of each embodiment of the present invention or embodiment
Method described in part.
The above description is merely a specific embodiment, but protection scope of the present invention is not limited thereto, any
Those familiar with the art in the technical scope disclosed by the present invention, all should by the change or replacement that can be readily occurred in
It is included within the scope of the present invention.Therefore, protection scope of the present invention should be subject to the protection scope in claims.
Claims (10)
1. a kind of nondestructive detection system based on current vortex pulse thermal imaging, which is characterized in that including：It is sensing heater, infrared
Thermal imaging system, processor, impulse generator, induction coil and sample temperature controller, wherein,
Under initial heating pulse signal and the heating pulse signal control that sensing heater is exported in impulse generator, generate high
Frequency alternating current, and provide current vortex by induction coil and encourage, to heat tested exemplar；Add in the stopping of impulse generator output
Under thermal impulse signals control, power cutoff；
Under the initial heating pulse signal control that thermal infrared imager is exported in impulse generator, the infrared hot spoke of tested exemplar is measured
The surface heat distribution to obtain tested exemplar is penetrated, and is imaged according to surface heat distribution, obtains infrared thermal imaging graphic sequence, it is defeated
Go out to processor；
Processor handles the infrared thermal imaging graphic sequence received, obtains the surface defect information of tested exemplar, and shows
Show the infrared thermal imaging of tested exemplar；
Sample temperature controller, for from the infrared thermal imaging graphic sequence, obtaining adopting for the predetermined sampled point of tested exemplar
Sample temperature if the sample temperature is not less than pre-set non-destructive testing high temperature threshold value, is exported to impulse generator and is stopped
Heating instructions if the sample temperature is not more than pre-set non-destructive testing low temperature threshold, are opened to impulse generator output
Dynamic heating instructions；
Impulse generator, after initial start, output initial heating pulse signal is with synchronous triggering sensing heater and infrared warm
It as instrument work, after stopping heating instructions being received, is exported to sensing heater and stops heating pulse signal, receiving heating
After instruction, heating pulse signal is exported to sensing heater.
2. the nondestructive detection system according to claim 1 based on current vortex pulse thermal imaging, which is characterized in that described to adopt
The quantity of sampling point is one or more, if the quantity of sampled point is multiple, sample temperature is the temperature change of multiple sampled points
Mean value.
3. the nondestructive detection system according to claim 1 or 2 based on current vortex pulse thermal imaging, which is characterized in that choosing
It is sampled point to take the high corresponding point of tested exemplar electric eddy current density or region.
4. the nondestructive detection system based on current vortex pulse thermal imaging according to claims 1 or 2 or 3, which is characterized in that
The non-destructive testing low temperature threshold is higher than environment temperature.
5. the nondestructive detection system according to any one of claims 1 to 4 based on current vortex pulse thermal imaging, feature exist
In the temperature difference of the non-destructive testing high temperature threshold value and tested exemplar scaling loss temperature is more than a constant value.
6. a kind of lossless detection method based on current vortex pulse thermal imaging, which is characterized in that including：
Sensing heater is controlled to generate high-frequency alternating current by initial heating pulse signal, providing current vortex with reference to induction coil swashs
It encourages to heat tested exemplar；
The infrared emanation of tested exemplar is measured to obtain the surface heat distribution of tested exemplar, and according to surface heat distribution carry out into
Picture obtains infrared thermal imaging graphic sequence；
Infrared thermal imaging graphic sequence is handled, obtains the sample temperature of the predetermined sampled point of tested exemplar；
If the sample temperature is not less than pre-set non-destructive testing high temperature threshold value, is exported to impulse generator and stop heating
Instruction if the sample temperature is not more than pre-set non-destructive testing low temperature threshold, starts to impulse generator output and adds
Heat instruction；
According to heating instructions control sensing heater deenergization is stopped, heater starting power supply is answered according to heating instructions Perceived control
Generate high-frequency alternating current.
7. the lossless detection method according to claim 6 based on current vortex pulse thermal imaging, which is characterized in that the side
Method can also include：
According to the infrared thermal imaging graphic sequence of processing, the surface defect information of tested exemplar is obtained, and shows the red of tested exemplar
Outer thermal imaging.
8. the lossless detection method based on current vortex pulse thermal imaging described according to claim 6 or 7, which is characterized in that institute
The quantity for stating sampled point is one or more, if the quantity of sampled point is multiple, sample temperature is the temperature of multiple sampled points
Change mean.
9. the nondestructive detection system based on current vortex pulse thermal imaging described according to claim 6 or 7, which is characterized in that choosing
It is sampled point to take the high corresponding point of tested exemplar electric eddy current density or region.
10. according to lossless detection method of claim 6 to 9 any one of them based on current vortex pulse thermal imaging, feature
It is, the non-destructive testing low temperature threshold is higher than environment temperature, the non-destructive testing high temperature threshold value and tested exemplar scaling loss temperature
The temperature difference be more than a constant value.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354380A (en) * | 2007-07-23 | 2009-01-28 | 北京航空航天大学 | Vortex flow and electromagnetic ultrasonic combined type nondestructive detection method |
| CN103646386A (en) * | 2013-12-05 | 2014-03-19 | 电子科技大学 | Thermal-image processing method capable of inhibiting effects of uneven thermal emissivity of material surface |
| CN103759651A (en) * | 2014-01-21 | 2014-04-30 | 沈阳师范大学 | Real-time monitoring variable temperature and pressure type laser speckle measuring system |
| CN104764770A (en) * | 2015-03-30 | 2015-07-08 | 南京航空航天大学 | Pulsed eddy current infrared thermal imaging detection system and method for steel rail cracks |
-
2018
- 2018-01-12 CN CN201810031692.4A patent/CN108195884A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354380A (en) * | 2007-07-23 | 2009-01-28 | 北京航空航天大学 | Vortex flow and electromagnetic ultrasonic combined type nondestructive detection method |
| CN103646386A (en) * | 2013-12-05 | 2014-03-19 | 电子科技大学 | Thermal-image processing method capable of inhibiting effects of uneven thermal emissivity of material surface |
| CN103759651A (en) * | 2014-01-21 | 2014-04-30 | 沈阳师范大学 | Real-time monitoring variable temperature and pressure type laser speckle measuring system |
| CN104764770A (en) * | 2015-03-30 | 2015-07-08 | 南京航空航天大学 | Pulsed eddy current infrared thermal imaging detection system and method for steel rail cracks |
Non-Patent Citations (2)
| Title |
|---|
| 梁宗裕 等: "《小家电故障检修实例》", 30 April 2006, 北京：金盾出版社 * |
| 白利兵: "电涡流脉冲热成像无损检测技术研究", 《中国博士学位论文全文数据库 工程科技I辑》 * |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN109580643A (en) * | 2018-12-14 | 2019-04-05 | 四川大学 | A kind of portable material microstructure defect detecting device |
| CN109613063A (en) * | 2019-01-17 | 2019-04-12 | 四川大学 | A kind of device and method based on face battle array pulse laser excitation detection thermal barrier coating face |
| CN110501384A (en) * | 2019-08-15 | 2019-11-26 | 东南大学 | A kind of bead wire curtain defect detecting device and detection method based on heat radiation visual pattern |
| CN111299894A (en) * | 2019-12-06 | 2020-06-19 | 深圳市瑞凌实业股份有限公司 | Welding defect detection system and method |
| CN111982967A (en) * | 2020-08-22 | 2020-11-24 | 核动力运行研究所 | Permanent magnet-based magnetic saturation pulse eddy current infrared nondestructive evaluation method |
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