CN1145897C - Digital image measuring method and equipment of triaxle testing sample soil deformation - Google Patents

Abstract

The present invention relates to a digital image measuring method and a device of triaxial test sample soil deformation, particularly to the application of a computer digital image identification technology in conventional earth work triaxial test sample deformation measurement. The device is composed of a triaxial compressometer, a digital image collection device and a microcomputer, a program is divided into a pixel equivalent weight calibration part and a triaxial test sample deformation measurement part, and each part is composed of an image collection and treatment module and an edge recognition and record module. The deformation of soil sample is not disturbed, the measuring method is contactless direct measurement, the measurement accuracy is increased, synchronous measurement of radial deformation and axial deformation for any part of the soil sample is realized, and the present invention can be widely applied to the triaxial test sample deformation measurement.

Description

The digital picture measuring method and the equipment of triaxial test specimen deformation

One, technical field:

The present invention relates to the application of computer digital image recognition technology in the geotechnological triaxial test sample deformation of routine is measured.

Two, background technology:

At present, ordinary triaxial test method key step is as follows: (1) with soil be cut into right cylinder be enclosed within the rubber membrane or directly in rubber membrane dress soil become sample, be put in the pressure chamber of sealing.The colligation of rubber membrane lower end is on base, and the upper end colligation separates interior pore water of sample and the water in the pressure chamber on the test cap fully.Pore water perhaps is communicated with drainpipe by the upper end permeable stone by the permeable stone and the measuring pore water pressure system connectivity of sample lower end.(2) in the pressure chamber, exert pressure, make test specimen respectively to being subjected to ambient pressure σ ₃, and hydraulic pressure is remained unchanged in entire test.(3) and then by transmission rod test specimen is applied vertical pressure, like this, vertical stress just greater than level to stress, when level remains unchanged to stress, and vertical stress is when increasing gradually, the test specimen sheared destruction.

The axial displacement of the axial deformation throughput test specimens cap of sample obtains, reflection be the overall axial deformation of soil sample, the axial strain that obtains in view of the above also is the axial mean strain of sample.The radial deformation of sample is to convert by the volume change of measuring soil sample to obtain, and the volume change of sample is then determined by the water body volume that sample is discharged in process of the test.Therefore what in fact obtain by test only is the average external volume strain of sample and the average radial strain of the sample integral body that obtains of conversion thus.But owing to be subjected to the influence of rigidity sample cap, the radial deformation of soil sample is extremely inhomogeneous in the process of the test, and therefore average radial deformation can not accurately reflect the radial strain state of soil sample.In addition also there is following defective in conventional earthwork triaxial apparatus aspect the deformation measurement: (1) can not count soil sample becomes soil sample in sample and the saturation history (setting pressure chamber, adding little confined pressure, to discharge suction, logical carbon dioxide and water filling saturated) on triaxial apparatus cubic deformation.(2) can not in measurement, eliminate rubber membrane and embed the cubing error that soil sample top layer hole causes that the water discharge variation brings.(3) can not consider the influence of soil sample end restraint to specimen deformation.(4) in order to measure radial deformation, require the soil sample must be saturated fully, this is not only time-consuming, and is difficult to usually accomplish.(5) for unsaturated soil, because can not determine the cubic deformation of soil sample, so can not be directly used in the test of unsaturated soil by the method for surveying water discharge.

To existing improvement measuring equipment of the radial deformation of sample and method be: Long Gang testing laboratory of (1) Tokyo Univ Japan adopts the radial strain instrument of local displacement sensor LDT and El-Ruwayih design, all is to measure the sample radial strain according to the variation of resistance in the conductor.(2) Escario﹠amp; Uriel adopts pure optical instrument, by the vertical markings of glass outer cover and the reading of sight line on scale of specimen finish, measures the size of specimen finish.(3) Morgn ﹠amp; Moore around the sample and stick on the rubber membrane with the thin layer silicone grease, utilizes micrometer microscope to survey distance between read flag with the variation of mensuration sample girth on banded aluminium foil.(4) Akai ﹠amp; The radial strain indicator that the intermediate altitude place of Acadchi by sample hangs up records diameter variation.(5) David M.Cole loses rule according to eddy current, and employing Kaman Multi-Vriel sensor is measured the radial deformation in the triaxial test.As mentioned above, have Many researchers to do a lot of effort, but more or less all there are some places not fully up to expectations in the method that they proposed for the direct measurement that realizes three sample radial deformations.As local displacement sensor LDT and radial strain instrument very high precision is arranged, but be difficult to adapt to large deformation, and operating difficulties when in the water of closed chamber, measuring; The problem that Kaman Multi-Vriel sensor exists is that static drift is arranged, and is difficult to the control survey precision; With the distance between the micrometer microscope record banded aluminium foil mark on the sample, process of the test is very complicated.Employing double pressure chamber can be carried out the stress-strain characteristics test of unsaturated soil at the normal triaxial instrument, and the average external volume that remains soil sample that still test obtains changes, and test apparatus is changed a social system, all more complicated are controlled and operated in test.

Three, summary of the invention:

The purpose of this invention is to provide a kind of distortion of not disturbing soil sample, contactless direct measurement, improve measuring accuracy, the any part of soil sample is realized the synchro measure of radial deformation and axial deformation, study the difference of soil sample local deformation characteristic and bulk deformation characteristic, can directly measure the digital picture measuring method and the equipment of the triaxial test specimen deformation of unsaturated soil distortion.

The object of the present invention is achieved like this: the digital picture measuring equipment of triaxial test specimen deformation, by triaxial apparatus, digital image acquisition apparatus and microcomputer are formed, the sealing cover of triaxial apparatus is a transparent toughened glass quad seal container, established standards diameter length on the base, soil sample to be measured is placed on the base, digital image acquisition apparatus is by charge-coupled device (CCD), focusing lens and magnifying glass are formed, the charge-coupled device (CCD) front end connects magnifying glass and focusing lens, dress video frequency collection card and display card in the microcomputer, the image of three soil samples is sent to computing machine by the charge-coupled device (CCD) collection and with the image that collects, computing machine is handled image, described processing comprises two parts: first is the demarcation of pixel equivalent, second portion is that three sample deformations are measured, and each part all is made up of with record two big modules with processing and edge identification the collection of image.

The digital picture measuring method of triaxial test specimen deformation is at first placed sample to triaxial apparatus, exerts pressure in the pressure chamber, and then by transmission rod sample is applied vertical pressure, calculates axial deformation and radial deformation,

First: horizontal, vertical pixel equivalent is demarcated,

The lateral pixel equivalent is demarcated:

(1), realizes shooting continuously by software control;

(2), in order to guarantee object central shaft symmetry, regulate charge-coupled device (CCD) and make image placed in the middle;

(3), place different pixel height place successively, image is analyzed and handled, detect and demarcate the left and right marginal position of thing, use formula K by software control demarcating thing _Nhll=column diameter/(right hand edge-left hand edge) calculates the lateral pixel equivalent at differing heights place, the pixel equivalent value that all demarcation obtain is stored in the two-dimensional data table, the pixel equivalent at feature point for calibration place carries out curve fitting with the unique point of having demarcated in other position and interpolation is tried to achieve;

Vertical pixel equivalent is demarcated and is demarcated with the lateral pixel equivalent;

Second portion: three sample deformations are measured, and use the rubber membrane dress soil that prints additional white marking on the surface to become sample, and deformation measurement is:

(1), realizes shooting continuously by software control;

(2), guarantee sample central shaft symmetry, the dislocation charge coupling device makes image placed in the middle;

(3), by software control image is analyzed and handled: detect the normal diameter length of setting on the triaxial apparatus base, determine image enlargement factor β; Also store the detection of sign position, calculates pixel height between the contiguous tokens line, directly reads from vertical pixel equivalent bivariate table or obtain corresponding pixel equivalent by interpolation method, uses formula H _Vi=N _i* K _NViTrue altitude between the * β calculation flag line; The left and right marginal position of test samples is also stored, and directly reads from lateral pixel equivalent bivariate table or obtains corresponding pixel equivalent by interpolation method, uses formula H _Hi=N _i* K _NHi* β calculates the true diameter of sample; The real-time length of output sample obtains different deflections constantly thus.

Advantage of the present invention is: the deformation measurement that the computer digital image measuring technique is applied to geotechnological triaxial test, (1) can realize the contactless direct measurement of soil sample axial deformation and radial deformation, reduced disturbance to sample body, has higher measuring accuracy, and realized that test is discerned, the record robotization, no longer require the sample must be saturated fully, reduce the labour intensity of testing crew greatly.(2) can get rid of the influence of soil sample two ends rigid base and sample cap to specimen deformation.(3) can measure the strain between any two the representative horizontal sections of soil sample, and the difference of research spot sample and whole sample stress-strain relation.(4) can catch the formation time of sample shear zone in the three axial compression compression process and form rule.(5) the normal triaxial compressometer can be applied to the experimental study of unsaturated soil.

Four, description of drawings:

Fig. 1 is existing triaxial apparatus structural representation.

Fig. 2 is the present device structural representation.

Fig. 3 demarcates process flow diagram for the lateral pixel equivalent.

Fig. 4 is that three sample deformations are measured process flow diagram.

Five, embodiment:

The digital picture measuring equipment of triaxial test specimen deformation as shown in Figure 2, is made up of triaxial apparatus, digital image acquisition apparatus and microcomputer.The sealing cover of triaxial apparatus is a transparent toughened glass quad seal container 1, established standards diameter length on the base; Digital image acquisition apparatus is made up of charge-coupled device (CCD) 2, focusing lens 3 and magnifying glass 4, and charge-coupled device (CCD) 2 front ends connect magnifying glass 4 and focusing lens 3; Dress video frequency collection card and display card in the microcomputer 6, the data line 5 of charge-coupled device (CCD) connects video frequency collection card.Program is in two sub-sections: first is the demarcation of pixel equivalent, and second portion is that three sample deformations are measured.Each part all by the collection of image and processing and edge identification and record two big module groups or.

Geotechnique's triaxial test is a kind of common method that is used for measuring native shearing strength.Triaxial apparatus by the pressure chamber, axially loading system, apply ambient pressure system, pore water pressure force measuring system etc. and form, as shown in Figure 1.The pressure chamber is the chief component of triaxial apparatus, and the pressure chamber is a tubular airtight container of being made up of metal top cover, base and organic glass in the normal triaxial instrument.Among the present invention, the pressure chamber changes the quad seal container of being made up of metal top cover, base and transparent toughened glass into, established standards diameter length on the base.

Digital image acquisition apparatus: charge-coupled device (CCD) (Charge Coupled Device) is selected Panasonic ccd video camera (MODEL:WV BP310/G, resolution: 800 (H) * 600 (V) for use.

NSK SK 12575 manual focusing camera lenses.

NSK X2 magnifying glass.

Video frequency collection card: Matrix Electronic Systems Ltd (Matrix Imagingadapter, Meteor PCI frame grabber (supporting 24 RGB high resolving power)).

Display card: Matrix Electronic systems Ltd (Matrix MGA MillenniumPower Desk (2M video memory), RAMDAC Speed:220MHz, Power DeskVersion:3.22.059).

Microcomputer: Pentium 100,24M EDORAM, 2.1G Fireball HD, 14 ' Bridge Monitor.

Geotechnique's triaxial test computer digital image measuring method mainly comprises charge-coupled device (CCD) shooting and computer digital image processing two parts.Its course of work may be summarized to be: the image of three soil samples is by the charge-coupled device (CCD) collection, be temporary in after handling through video frequency collection card in frame deposits, pass through routine processes again, the information during frame is deposited is mixed with the graph text that needs, and delivers to display by display card.Information in simultaneously frame being deposited is carried out analyzing and processing, determines shape and then definite deflection of soil sample by the recognition image edge.

One of the primary clustering of measuring system charge-coupled device (CCD), it is with the form storage and the transmission information of charge packet.The charge-coupled device (CCD) device has the branch of linear array and face battle array.The present invention adopts face battle array black and white charge-coupled device (CCD), and it constitutes photodevice matrix by 800 * 600 photodiodes.When Scenery Imaging was on photosurface, each photodiode was accepted the strong and weak different of light, the optical charge of the different amounts of inducting.The optical charge that accumulates is under the effect of driving pulse, by the output circuit outputting video signal.A/D converter in charge-coupled device (CCD) and the image acquisition circuit is finished the sampling and the quantification work of image, makes analog image be converted to digital picture, is convenient to the identification and the processing of computing machine.

The deformation of any continuous object all shows as the change in location of object edge on macroscopic view.Therefore the computer digital image of specimen deformation is measured, and is exactly real time record and identification soil sample edge and the variation that detects its position.The edge of object can be reflected by the uncontinuity of gray scale under the black and white image-forming condition, is divided into step evolution edge and shape edge, roof roughly.The pixel gray-scale value at step evolution edge has remarkable difference near the edge; Shape edge, roof then is positioned at the variation turning point place of gray-scale value.With the Changing Pattern of contiguous first order derivative in edge or second derivative, just can find out the position at place, edge.

In the digital picture measuring system, because non-linear to optical device itself such as the refraction of light and zoom lens, magnifying glass, charge-coupled device (CCD)s such as water body in the tempered glass seal closure, confined pressure chamber can cause the pattern distortion distortion.The existence of pattern distortion means that the object of equal length can obtain the image of different length in different imaging regions, and this must cause bigger measuring error, influences measuring accuracy.Find that by test pattern distortion has evident regularity in the entire image zone, belong to systematic error, can revise.The demarcation of first's pixel equivalent of measuring method, exactly systematic error is revised, therefore after every group of device assembles, what at first carry out is exactly the demarcation of pixel equivalent, and equivalent value is stored in the two-dimensional data table, each later on the measurement only needs the data in the corresponding bivariate table are found, calculate analog value and get final product, carry out the correction of systematic error when the digital picture Survey Software realizes deformation measurement.Programming language is selected Visual Basic for use, has called some the existing built-in functions in the Matrix graphical development storehouse simultaneously, and measuring method is as described below.

At first place sample, in the pressure chamber, exert pressure, and then sample is applied vertical pressure, calculate axial deformation and radial deformation, it is characterized in that by transmission rod to triaxial apparatus:

First: horizontal, vertical pixel equivalent is demarcated,

Lateral pixel equivalent calibrating procedure is:

(1), the beginning, the MdigGrabContinuous function that at first calls in the Matrix graphical development storehouse is made a video recording continuously;

(2), in order to guarantee object central shaft symmetry, need to judge whether demarcate thing be in the entire image center, if not, regulate charge-coupled device (CCD) and make image placed in the middle;

(3), place different pixel height place successively, the MbufGet function that calls in the Matrix graphical development storehouse obtains the digital image information data, and image is analyzed and handled, and detects and demarcates the left and right marginal position of thing, uses formula K demarcating thing _Nhll=column diameter/(right hand edge-left hand edge) calculates the lateral pixel equivalent at differing heights place; Judging whether to demarcate in addition thing needs to demarcate, if do not have, the pixel equivalent value that all demarcation obtain is stored in the two-dimensional data table termination routine; The pixel equivalent at feature point for calibration place carries out curve fitting with the unique point of having demarcated in other position and interpolation is tried to achieve; Vertical pixel equivalent is demarcated with lateral pixel equivalent calibrating procedure; Two-dimensional data table is:

${\left[\begin{array}{ccc}{K}_{\mathrm{nH}11}& K_{\mathrm{nH}12}& K_{\mathrm{nH}1n}\\ K_{\mathrm{nH}21}& K_{\mathrm{nH}22}& K_{\mathrm{nH}2n}\\ K_{\mathrm{nHm}1}& K_{\mathrm{nHm}2}& K_{\mathrm{nHm}3}\end{array}\right]}_{m\×n}$

Second portion: three sample deformations are measured, and use the rubber membrane dress soil that prints additional white marking on the surface to become sample, and the deformation measurement program is:

(1), the beginning, the MdigGrabContinuous function that at first calls in the Matrix graphical development storehouse is made a video recording continuously;

(2), in order to guarantee sample central shaft symmetry, judge whether Sample Image is in the center, if not, the dislocation charge coupling device makes image placed in the middle;

(3), the MbufGet function that calls in the Matrix graphical development storehouse obtains the digital image information data, image is analyzed and is handled: detect the normal diameter length of setting on the triaxial apparatus base, determine image enlargement factor β; Also store the detection of sign position, calculates pixel height between the contiguous tokens line, directly reads from vertical pixel equivalent bivariate table or obtain corresponding pixel equivalent by interpolation method, uses formula H _Vi=N _i* K _NhViTrue altitude between the * β calculation flag line; The left and right marginal position of test samples is also stored, and directly reads from lateral pixel equivalent bivariate table or obtains corresponding pixel equivalent by interpolation method, uses formula H _Hi=N _i* K _NHi* β calculates the true diameter of sample; The real-time length of output sample obtains different deflections constantly thus; Judge whether to continue to measure, continue said process, otherwise termination routine if desired.

Axial stress in the triaxial test is with the stressed actual loading area divided by sample body in the sample deformation process of sample, because prior art there are differences according to cubic deformation and axial deformation conversion sample mean lifting surface area that obtains and the sample area that the diameter that measures with the present invention program's digital picture calculates, so also there is some difference with axial stress that two kinds of distinct methods calculate, it is big directly to measure the radial strain that the radial strain that obtains obtains than converting with conventional method with the digital picture measuring method at the axial central part of soil sample.In practical operation, can obtain testing the average radial distortion of soil sample on the radial deformation of any horizontal section of soil sample or any one section height, for the intensity and the stress-strain Constitutive Relationship of the research soil body provides more accurately, measurement means easily.Adopt digital picture measuring technique of the present invention, the strain measurement precision of soil sample can reach 2.0 * 10 ^-4-3.0 * 10 ^-4, satisfy and accurately measure purpose.

Provide present embodiment one program segment, support the present invention program.Below this section program be to measure the pixels across equivalent of calibration cylinder in a certain position " ' defining variable " " "

Dim B1 (0 To 442367) As ByteDim Pos Y, i, j, Margin 1, Margin2, Counter As IntegerDim datastr As StringDim tMargin1, tMargin2, rMargin1, rMargin2, vv1, vv2, vv3, vv4 AsSingleDim k As LongDim Kn1 (10), L1, L2, Km1, Km2 As Singlebegin: " " " ' shooting and reads image data (gray-scale value) be in the array B1 () " " " " " " ' If StartYesNo=1 Then＜!--SIPO＜DP n=" 6 "〉--〉＜dp n=" d6 "/MdigHalt (MilDigitizer) Call MbufGet (MilBuffer, B1 (0)) Cau MdigGrabContinuous (MilDigitizer, MilBuffer) Else Call MdigGrabContinuous (MilDigitizer, MilBuffer) MdigHalt (MilDigitizer) Call MbufGet (MilBuffer, B1 (0)) End Ifk=Val (Text6.Text) * 768Ifk=0 Then MsgBox " please the input position value! " Exit SubEnd IfKn=0Counter=10Forj=1 to 10 k=k+ (j-4) * 768 " " " calculating left hand edge rough position " " " ' For i=5 To 398 If (CDec (B1 (i-1+k))-CDec (B1 (i+K)))＞TH And (CDec (B1 (i+k))-CDec (B1 (i+1+k)))＞TH And (CDec (B1 (i+1+k))-CDec (B1 (i+2+k)))＞TH Then If Abs (CDec (B1 (i+20+k))-CDec (B1 (i+50+k)))＞35Then Else Margin1=i GoTo ok1 End If End If Next " " " calculating left hand edge sub-pixel location " " " ' ok1:vv1=0:vv2=0＜!--SIPO＜DP n="7"〉--〉＜dp n="d7"/〉 For i＝Margin1-LPixelnum1 to Margin1-LPixelnum2 vv1＝vv1+B1   (  i+k  )  Next For i＝Margin1+RPixelnum2 To Margin1+RPixelnum1 vv2＝vv2+B1   (  i+k  )  Next tMargin1＝   (  vv1/10+vv2/10  )  /2 For i＝Margin1-10 To Margin1+10 IfB1   (  i+k  )＞tMargin1 And B1   (  i+1+k  )＜tMargin1 Then rMargin1＝i+   (  B1   (  i+k  )-tMargin1  )  /   (  B1   (  i+k  )-B1   (  i+1+k  )   )  End If Next ””””””’ For i＝760 To 400 Step-1 If   (  CDec   (  B1   (  i-1+k  )   )-CDec   (  B1   (  i+k  )   )   )＜-TH And   (  CDec   (  B1   (  i+k  )   )-CDec   (  B1   (  i+1+k  )   )   )＜-TH And   (  CDec   (  B1   (  i+1+k  )   )-CDec   (  B1   (  i+2+k  )   )   )＜-TH Then′And   (  CDec   (  B1   (  i+2+k  )   )-CDec   (  B1   (  i+3+k  )   )   )＜-TH Then If Abs   (  CDec   (  B1   (  i-20+k  )   )-CDec   (  B1   (  i-50+k  )   )   )＞35Then′Form5.R1.Text＝Form5.R1.Text+Trim   (  str   (  i  )   )  +str   (  CDec   (  B1   (  i+k  )   )-CDec   (  B1   (  i+1+k  )   )   )  +Chr   (  10  )  +Chr   (  13  )  Else Margm2＝i GoTo ok2 End If End If Next ””””””’ok2： vv1＝0：vv2＝0 For i＝Margin2-RPixelnum1 To Margin2-RPixelnum2 vv1＝vv1+B1   (  i+k  )  Next For i＝Margin2+LPixelnum2 To Margin2+LPixelnum1 vv2＝vv2+B1   (  i+k  )  Next tMargin2＝   (  vv1/10+vv2/10  )  /2 For i＝Margin2-10 To Margin2+10＜!--SIPO＜DP n="8"〉--〉＜dp n="d8"/〉 IfB1   (  i+k  )＜tMargin2 And B1   (  i+1+k  )＞tMargin2 Then rMargin2＝i+1-  (  B1   (  i+1+k  )-tMargin2  )  /   (  B1   (  i+1+k  )-B1   (  i+k  )   )  End If Next ””””””” Kn1   (  j  )  ＝   (  rMargin2-rMargin1  )  Kn＝Kn+Kn1   (  j  )  NextKn＝Kn/10For i＝1 To 10 If Abs   (  Kn1   (  i  )-Kn  )＞10 Then Kn1   (  i  )  ＝0 Counter＝Counter-1 End IfNextIfCounter＝0 Then Erase B1 GoTo beginEnd IfKn＝0For i＝1 To 10 Kn＝Kn+Kn1   (  i  )  NextKn＝   (  Kn/Counter  )  Text10.Text＝str   (  Kn  )  L1＝KnKn＝Val   (  C1.Text  )  /KnKm1＝Val   (  C1.Text  )  rMar1＝rMargin1rMar2＝rMargin2Text11.Text＝str   (  Val   (  Text11.Text  )  +1  )  Erase B1

Claims (2)

1, the digital picture measuring equipment of triaxial test specimen deformation, it is characterized in that: by triaxial apparatus, digital image acquisition apparatus and microcomputer are formed, the sealing cover of triaxial apparatus is a transparent toughened glass quad seal container (1), established standards diameter length on the base, soil sample to be measured is placed on the base, digital image acquisition apparatus is by charge-coupled device (CCD) (2), focusing lens (3) and magnifying glass (4) are formed, charge-coupled device (CCD) (2) front end connects magnifying glass (4) and focusing lens (3), dress video frequency collection card and display card in the microcomputer (6), the image of three soil samples is sent to computing machine by the charge-coupled device (CCD) collection and with the image that collects, computing machine is handled image, described processing comprises two parts: first is the demarcation of pixel equivalent, second portion is that three sample deformations are measured, and each part all is made up of with record two big modules with processing and edge identification the collection of image.

2, the digital picture measuring method of triaxial test specimen deformation is at first placed sample to triaxial apparatus, exerts pressure in the pressure chamber, and then by transmission rod sample is applied vertical pressure, calculates axial deformation and radial deformation, it is characterized in that:

First: horizontal, vertical pixel equivalent is demarcated,

The lateral pixel equivalent is demarcated:

(1), realizes shooting continuously by software control;

(2), in order to guarantee object central shaft symmetry, regulate charge-coupled device (CCD) and make image placed in the middle;

(3), place different pixel height place successively, image is analyzed and handled, detect and demarcate the left and right marginal position of thing, use formula K by software control demarcating thing _Nhll=column diameter/(right hand edge-left hand edge) calculates the lateral pixel equivalent at differing heights place, the pixel equivalent value that all demarcation obtain is stored in the two-dimensional data table, the pixel equivalent at feature point for calibration place carries out curve fitting with the unique point of having demarcated in other position and interpolation is tried to achieve;

Vertical pixel equivalent is demarcated and is demarcated with the lateral pixel equivalent;

Second portion: three sample deformations are measured, and use the rubber membrane dress soil that prints additional white marking on the surface to become sample, and deformation measurement is:

(1), realizes shooting continuously by software control;

(2), guarantee sample central shaft symmetry, the dislocation charge coupling device makes image placed in the middle;

(3), by software control image is analyzed and handled: detect the normal diameter length of setting on the triaxial apparatus base, determine image enlargement factor β; Also store the detection of sign position, calculates pixel height between the contiguous tokens line, directly reads from vertical pixel equivalent bivariate table or obtain corresponding pixel equivalent by interpolation method, uses formula H _Vi=N _i* K _NViTrue altitude between the * β calculation flag line; The left and right marginal position of test samples is also stored, and directly reads from lateral pixel equivalent bivariate table or obtains corresponding pixel equivalent by interpolation method, uses formula H _Hi=N _i* K _NHi* β calculates the true diameter of sample; The real-time length of output sample obtains different deflections constantly thus.

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