A method of the digital picture based on building curtain wall surface monitors its in-plane deformationTechnical field
A kind of monitoring method of building curtain wall in-plane deformation of the present invention is based on building curtain wall table especially in regard to one kindThe method that the digital picture in face monitors its in-plane deformation.
Background technique
Building curtain wall passes through development in more than 30 years, the features such as because of its graceful appearance, the lighter scale of construction and heat preservation energy-saving,It is widely used among the design of heavy construction structure.Simultaneously it is also noted that building curtain wall during service because of earthquake, wind load, buildBuilding object to involve the deformation of curtain wall caused by the factors such as sedimentation is to influence the principal element of overall performance.When these Load Combinations act onCause on the surface of building curtain wall the rupture that will lead to curtain wall unit when the deformation more than curtain wall limit of bearing capacity toLead to safety accident.According to the above reason, assessed by detecting its in-plane deformation under Load Combination effect to building curtain wallIts security performance during one's term of military service, is link important in engineering project quality inspection and Architectural Mechanics performance monitoring.
Main stream approach to monitoring and the evaluation of building curtain wall in-plane deformation is passed through using Quintic system loading test deviceTest is to restore Load Combination effect.Specific method is, in the connecting corner yard of curtain wall test specimen and Quintic system loading device walking beamPlace arranges displacement meter by curtain wall member side, then start-up loading device, and walking beam is made to carry out the period to, Z-direction or both combination along XIt moves back and forth and then involves building curtain wall and deform, the corresponding position for arranging displacement meter is obtained while carrying out period loadDisplacement information, and then the story drift and plane internal deformation on the curtain wall surface under calculating cycle load action come with thisEvaluate the graded index of building curtain wall produced deformation under seismic loading.The relatively simple load that reappeared of this method is appliedThe case where adding effect, also intuitively having measured building curtain wall in-plane deformation, but there are certain limitations: 1) corner brace at use biographyThe displacement meter of system measures, though accurate data can be obtained intuitively, it only passes through the displacement of several definite measured key points positionInformation describes the in-plane deformation of monolith curtain wall, causes the most weak location point for destroying position with making curtain wall unit its deformationWith material, construct for handling characteristic and it is different.Original method measures the key point chosen in test may not be able toThis partial information is captured completely；2) this method removes outer using traditional displacement meter measurement, by gradual increase each periodDisplacement amplitude destroys situation until generating destruction, the crackle etc. that only detects by an unaided eye to judge curtain wall grade, this is clearly not smart enoughTrue；3) due to the diversification of curtain wall form, traditional displacement meter arrangement key point is measured for more symmetrical easy structureIt is desirable, but the special circumstances such as labyrinth or small space is difficult directly to arrange that displacement meter directly measures；4) with buildingCurtain wall rapid development is built, is extended to large scale structure, Multispans continuous engineer application from simple single panel, this all improves changeThe requirement of the spatial extent and spatial resolution to be studied of shape monitoring.The in-plane deformation monitoring range of curtain wall require it is increasing andPrecision also requires higher and higher.If undoubtedly needed in such a way that tradition is based on displacement meter measurement in Quintic system loading deviceThe upper a large amount of displacement meter of arrangement, either financial resources are still technically all difficult to realize, for large structure, this measurementMode is undoubtedly equal to local deformation measurement and non-integral measurement of full field.
Summary of the invention
For defect and problem existing for current mainstream measurement method, the object of the present invention is to provide one kind based on building curtainThe method that the digital picture on wall surface monitors its in-plane deformation.
To achieve the above object, the invention adopts the following technical scheme: a kind of digital picture based on building curtain wall surfaceThe method for monitoring its in-plane deformation, step include: 1) according to testing the requirement of single axial direction or combined effect for building to be measuredCurtain wall is fixed on the corresponding walking beam of Quintic system loading device；2) guarantee that entire curtain wall test surfaces to be measured are placed in camera perspectiveIn range, an industrial digital camera is set up, need to guarantee that camera optical axis is vertical with curtain wall surface to be measured, and by industrial digital cameraIt is connect with computer, starts digital image acquisition software；3) it opens a whole set of digital imaging system and starts Quintic system loading device,The effect of uniaxial or combined cycle shift reciprocately is applied to curtain wall and applies displacement step by step, while being continuously shot one using cameraThe corresponding displacement grade of sequence photographs record acts on the digital speckle image on lower curtain wall surface；4) two-dimensional digital is utilized on computersImage correlation matching algorithm carries out relevant matches to a series of digital picture of corresponding displacement grade effects collected in experimentIt calculates, obtains the whole audience displacement information of building curtain wall in-plane deformation.The present invention overcomes use tradition displacement meter measurement method pairThe limitation of measurement and the unreliability that visually observation curtain wall destroys, the invention pass through to measurement period camera imaging sequence ratioThe whole audience in-plane deformation information that curtain wall surface can quantitatively be obtained in the case where not needing contact measurement to calculating, so that curtain wallDeformation monitoring test accuracy and stability simplify test process while improving, and cost is less expensive.
In the step 1), if the surface of building curtain wall to be measured does not possess the natural texture of sufficiently random characteristic, needSpeckle label is artificially added on curtain wall surface to be measured before experiment: to guarantee that contrast and the maximization of image recognition accuracy canTo use the gimmick spot of white with black point, uses the dumb light paint spraying curtain wall surface of black as background first, reuse whiteDumb light paint is sprayed on curtain wall surface in particle random distribution state, needs to guarantee that individual particle point size is not take up camera acquisitionMultiple pixels of photo are to reduce imaging precision.
In the step 2), the optical axis of camera needs face curtain wall center to guarantee that entire curtain wall test surfaces can be in cameraPicture is captured in vision range, while need to also ensure dissipating in plane to be measured before testing by adjusting the aperture and focal length of cameraSpot pattern imaging clearly, to make precision maximization maximize object under test in vision range as far as possible.
In the step 3), three relatively reciprocal periods should be made by carrying out displacement application process in Quintic system load means,Each period is about 3s-10s, and increases displacement step by step.To curtain wall knot can be opened after the completion of each displacement grade appliesStructure carries out switch testing detection.A cycle displacement is first carried out before experiment starts to apply as preloading step, to check curtainWall connecting corner yard and the relative displacement situation of walking beam simultaneously make amendment.Carry out later displacement the period apply and start photo sequenceShooting is stored in computer.
In the step 4), the matching process step of two-dimensional digital image related algorithm is as follows:
A) shooting does not generate the curtain wall speckle image of Displacement-deformation as reference picture before experiment.Select each group of difference positionUnder the effect of shifting amplitude, last width digital speckle image in current period, as the target image in the case of research maximum displacement；
B) determination will monitor region in selected reference picture；
C) sampled point is selected in monitoring region；
D) relevant calculation sub-district is determined, while corresponding position determines region of search in the target image；
E) it is based on following relevant matches criterion, carries out relevant matches calculating in image after deformation:
Wherein, C is the related coefficient between two sub-districts, and the coefficient is smaller, illustrates that two sub-districts are closer；f(xi,yj)With g (x 'i,y′j) it is respectively the gray value function for deforming front and back curtain wall surface corresponding position；
F) the smallest position of related coefficient is most likely location after the sampling point deformation after carrying out whole audience search, is calculatedCoordinate difference between the position and initial position can obtain motion vector of this after curtain wall in-plane deformation；
G) step d)~f is repeated to sampled point all in monitoring region), the displacement letter of all sampled points can be obtainedBreath；
H) displacement information based on all sampled points rebuilds the whole field deformation information on whole building curtain wall surface.
The present invention due to using the technology described above, has the advantage that 1) the present invention is based on two-dimensional digital image correlationsAlgorithm calculates the detection of building curtain wall whole audience in-plane deformation, and the deformation information of curtain wall surface any position can be quantitatively evaluated, andThere can only be extreme position to carry out displacement measurement arrangement measuring point in tradition displacement meter measurement method；2) present invention is a kind of non-contactThe measurement method of formula: due to use picture catching computing technique without the ontology of direct contact measurement curtain wall just can be carried out toSurvey the deformation monitoring on surface；3) present invention can complete large-scale superelevation by improving camera properties and position progress digital imageryLayer building curtain wall etc. is not easy to artificially add the research of traditional measurement instrument.Therefore this method have high resolution precision it is strong,The advantages that convenient for operating and being low in cost, stability is strong, has actual promotional value.
Detailed description of the invention
Fig. 1 is the device of the invention schematic diagram.
Fig. 2 is performance deciding grade and level detection loading sequence step.
Specific embodiment
Below in conjunction with attached drawing, specific embodiments of the present invention will be further explained:
In conjunction with Fig. 1~2, the present invention including the following steps:
Step 1: building curtain wall to be measured is fixed on by Quintic system load according to the requirement for testing single axial direction or combined effectSuch as Fig. 1 on the corresponding walking beam of device；
Step 2: guaranteeing that entire curtain wall test surfaces to be measured are placed in camera perspective range, sets up the digital phase of an industryMachine need to guarantee that camera optical axis is vertical with curtain wall surface to be measured, and industrial digital camera is connect with computer, start digital pictureAcquisition software；
Step 3: opening a whole set of digital imaging system and start Quintic system loading device, applies uniaxial or combination to curtain wallPeriod shift reciprocately acts on and applies step by step displacement, while being continuously shot a sequence photographs using camera and recording corresponding displacementGrade acts on the digital speckle image on lower curtain wall surface；
Step 4: two-dimensional digital image correlation matching algorithm is utilized on computers, to collected a series of in experimentThe digital picture of corresponding displacement grade effect carries out relevant matches calculating, obtains the whole audience displacement letter of building curtain wall in-plane deformationBreath.
In the step 1, if the surface of building curtain wall to be measured does not possess the natural texture of sufficiently random characteristic, needSpeckle label is artificially added on curtain wall surface to be measured before experiment: to guarantee that contrast and the maximization of image recognition accuracy canTo use the gimmick spot of white with black point, uses the dumb light paint spraying curtain wall surface of black as background first, reuse whiteDumb light paint is sprayed on curtain wall surface in particle random distribution state, needs to guarantee that individual particle point size is not take up camera acquisitionMultiple pixels of photo are to reduce imaging precision.
In the step 2, the optical axis of camera needs face curtain wall center to guarantee that entire curtain wall test surfaces can be in cameraPicture is captured in vision range, while need to also ensure dissipating in plane to be measured before testing by adjusting the aperture and focal length of cameraSpot pattern imaging clearly, to make precision maximization maximize object under test in vision range as far as possible.
In the step 3, carrying out displacement application process in Quintic system load means should be relatively reciprocal according to work as shown in the figureIn three periods, each period is about 3s-10s, and increases displacement step by step.It is indicated at time shaft stain to can open in figureThe curtain wall construction carry out activity test of characteristic, the displacement of initial a cycle is applied for the preloading step before experiment in figure, withIt checks the relative displacement situation of curtain wall connecting corner yard and walking beam and makes amendment.Carry out later displacement the period apply and start to shineThe shooting of piece sequence is stored in computer.
In the step 4, the matching process step of two-dimensional digital image related algorithm is as follows:
A) shooting does not generate the curtain wall speckle image of Displacement-deformation as reference picture before experiment.Select each group of difference positionUnder the effect of shifting amplitude, last width digital speckle image in current period, as the target image in the case of research maximum displacement；
B) determination will monitor region in selected reference picture；
C) sampled point is selected by the sampling interval of 30 pixels in monitoring region；
D) determine relevant calculation sub-district size select, constituency centered on sampled point, 15 pixels for radius rectangleRegion, while corresponding position determines region of search in the target image；
E) it is based on following relevant matches criterion, carries out relevant matches calculating in image after deformation:
Wherein, C is the related coefficient between two sub-districts, and the coefficient is smaller, illustrates that two sub-districts are closer；f(xi,yj)With g (x 'i,y′j) it is respectively the gray value function for deforming front and back curtain wall surface corresponding position；
F) the smallest position of related coefficient is most likely location after the sampling point deformation after carrying out whole audience search, is calculatedCoordinate difference between the position and initial position can obtain motion vector of this after curtain wall in-plane deformation；
G) step d)~f is repeated to sampled point all in monitoring region), the displacement letter of all sampled points can be obtainedBreath；
H) displacement information based on all sampled points rebuilds the whole field deformation information on whole building curtain wall surface.
Fig. 1 illustrates experimental rig figure of the invention.To guarantee that camera shoots speckle optimal quality, first by building curtain wallSurface even application black matte paint to be measured is used as priming paint, then marks in the case where guarantee possesses sufficiently random characteristic whiteColor dumb light paint speckles form random speckle pattern shown in the lower right corner in Fig. 1.Curtain wall to be measured is fixed on Quintic system device phaseOn the walking beam answered.Building curtain wall front arrange an industrial camera, it is desirable that camera optical axis face curtain wall centroid and hang downDirectly in surface to be measured, by camera connection computer to control image acquisition procedure.
Quintic system loading device applies the mode being displaced during Fig. 2 illustrates test.As shown, having carried out altogether primaryThe prestressing force load of a cycle by a definite date, increases displacement amplitude, three periods by a definite date displacement four times step by step.Prestressing force loadThere is no relative displacement with curtain wall for confirmation connecting corner yard building.For mobilizable curtain wall unit, carried out at time shaft stainThe activity operations such as open and close.