CN103075979A - Three-dimensional surface detecting device and three-dimensional surface detecting method - Google Patents

Abstract

The present invention provides a three-dimensional surface detecting device which has the following advantages: simple structure, low cost, high detecting speed and high detecting precision. The three-dimensional surface detecting device is used for detecting three-dimensional defects such as surface recess and shape change along with larger scratch on the objects with strong mirror reflection. The three-dimensional surface detecting device mainly comprises the following components: a photographing device 3 which photographs the image of a photographed object X; a light filtering film which covers the circumference of the photographed object and is set to a curved surface; and a curved-surface-shaped structure light projecting unit 5 which projects curved-surface-shaped structure light to the photographed object, wherein the strength of the curved-surface-shaped structure light is in periodical arrangement along the shape of the curved-surface-shaped light filtering film, wherein decoding processing is performed on the image of the detected object which is photographed thorugh the photographing device 3, and the curved-surface-shaped strength arrangement is changed to linear strength arrangement; and a defect detecting unit 13 which detects three-dimensional defects on the surface of the detected object through image processing.

Description

Three-dimensional surface pick-up unit and three-dimensional surface detection method

Technical field

The invention provides a kind of non-contact three-dimensional pick-up unit and 3 D detection method, for detection of the surface pitting of the objects such as automobile and parts thereof and be accompanied by larger cut and the 3 D stereo defectives such as three-dimensional deformation that produce.

Background technology

In fields such as automobile production, auto parts and components cycling and reutilizations, the detection that the cut on body of a motor car surface, indenture, application are peeled off etc. is very important.Yet, mostly undertaken by Quality Controller's range estimation such as above-mentioned these quality testings now.Because the difference of Quality Controller's professional skill, the result who detects is also uneven.In addition, range estimation detects that not only workload is huge, and because job specification important also can bring very large mental burden to the overlooker.Therefore, people's digital camera devices such as using digital camera or digital camera that waits in expectation, go to realize noncontact, at a high speed, high-precision body surface detects.

The measurement that as body of a motor car, has the object of three-dimensional shape, the method that can use three-dimensional image to measure.Three-dimensional image is measured and can be divided into passive measurement method and active mensuration two large classes.The representative method of passive measurement method is the binocular vision method, it use 2 cameras from the photo of different visual angle shot objects, seek corresponding point at photo and mate and then calculate its three dimensional space coordinate.Contour shape that this method is highly suitable for measuring object etc. has the part of obvious characteristic, but not too is applicable to measure part or the object of unique point rareness, as changes slowly curved surface etc.

As the representative method of active mensuration, we can enumerate the structured light projection mensuration.The structured light projection mensuration has been made some unique points on the testee surface artificially by to testee projective structure light, even if picture changes the slowly part of the unique point rareness of curved surface etc. like this, also can measure.

In addition, the phase shifts mensuration also is widely known by the people.This method be to testee projection such as sine wave such have a structured light that space periodic changes, then the space phase of moving structure light, utilize many different reflected light images of space phase to resolve.For example, in order to shorten Measuring Time, the raising measuring accuracy based on the three-dimensional image measuring method of structured light projection principle, people have invented the method thatpatent documentation 1 and 2 is put down in writing.The feature of the method for patent documentation 1 is that it has used optimum strength modulated structure light, only needs projection primary structure light just can realize the three-dimensional image measurement of testee, has improved measuring accuracy thereby shortened Measuring Time.But this method also is not suitable for the measurement on body of a motor car surface, because the surface reflection of body of a motor car is too strong.

The feature of the method forpatent documentation 2 records is that it uses the higher measurement of density with structured light and datum line structured light, to realize more high accuracy three-dimensional image measurement.But it is difficult to be exposed for the stronger object of surface emitting with bright spot reflection.That is to say that the general three-dimensional image measuring method based on structured light projection be difficult to be exposed for the very object in high light pool that has as car body, that is this method can't be applicable to the stronger object of surperficial mirror-reflection.

For the measurement of the stronger object of surperficial minute surface reflection strength, people have proposed the method forpatent documentation 3 and 4.Patent documentation 3 has proposed a kind of means of illumination, so that the light that lighting source sends can not shine directly on the testee, thereby so that the measurement of the stronger object of surface reflection becomes possibility.In addition, patent documentation 4 has proposed a kind of method, and its uses the light and shade structured light of linearity that testee is carried out projection, the marginal feature of the light and shade structured light in its reflected image is resolved, thereby detect the indenture of body surface.It can be for detection of the concavo-convex defective on car body surface.

The above-mentioned patent documentation of quoting is listed as follows:

Patent documentation 1: Japan, JP 2006-145405 communique

Patent documentation 2: Japan, JP 2011-185872 communique

Patent documentation 3: Japan, JP 2010-185820 communique

Patent documentation 4: Japan, JP 2010-85165 communique

Summary of the invention

Yet the method that above-mentionedpatent documentation 3 proposes is the two dimensional image treatment technology owing to what use, so although it can detect the defective of the bidimensionals such as scar on car body surface, can't detect the three-dimensional informations such as the degree of depth of indenture.In addition, the method that patent documentation 4 proposes is the side information that utilizes the light and shade structured light, the disposal route of using two dimensional image to resolve because its adopts, so although it can detect deformation of unevenness, be difficult to measure the height of the degree of depth or the projection of indenture.In addition, the method for patent documentation 4, the part beyond the edge that can't detection architecture light, being limited in scope of measurement.

For this reason, the objective of the invention is to propose a kind of three-dimensional surface checkout equipment for detection of the stronger testee of surperficial mirror-reflection and three-dimensional surface detection method, only use simple structure and lower cost structure, just can detect the indenture of body surface high-speed, high precision and be accompanied by larger cut and the 3 D defects such as 3 D stereo deformation that produce.

The three site surface pick-up units that the present invention proposes comprise following components: the photographic means of taking the image of measurand object; Be made into the curved surface shape and shroud light filter film around the testee; See through light filter film to the curved-surface structure light projecting cell of measurand object projection curved-surface structure light, the spatial-intensity of this curved-surface structure light is along the periodic spatial intensity distribution of the Surface forming of light filter film; And taken image decoded to process its curved surface shape intensity distributions is transformed to linearity distributes, and then detect the defect detection unit of the 3 D defects of body surface.

In addition, detection method proposed by the invention has following characteristics: for being made into the curved surface shape and shrouding at testee light filter film on every side, see through this light filter film to measurand object projection curved-surface structure light, the spatial-intensity of this curved-surface structure light is along the periodic spatial intensity distribution of the Surface forming of light filter film; Utilize photographic means to obtain the image information of measurand object, taken image is decoded to process to be transformed to linearity with its curved surface shape intensity distributions and to distribute, and then detects the 3 D defects of body surface.

The present invention is not because directly to measurand project objects structured light but carry out projection by light filter film, therefore light source can directly not shone upon by body surface, even if so the object very strong to mirror-reflection also can be taken as the object that does not have mirror-reflection and needn't consider the problem of surface reflection.So just, be easy to take the image of testee and from the image that photographs, detect the existing defective of measurand body surface.In this process, be projected to projection light intensity on the testee and be along the curved surface of light filter film and be period profile.Then, by processing that the image that photographs is decoded, can make its intensity distributions become linearity by the curved surface shape.Like this, because the intensity distributions of the 3 D defects part that exists on the measured object surface is non-linear shape, we just can whether linearity judges whether to exist 3 D defects according to the intensity distributions of image.

Use method and apparatus of the present invention, because projected light can directly not be mapped to the testee surface, even if so for the very strong measurand object of minute surface emission, also can be as to the object that does not have mirror-reflection, taking pictures simply, and from resulting image, detect simply the defective on testee surface.So just, can detect at a high speed, accurately the indenture of testee surface existence and be accompanied by the 3 D defects such as three-dimensional deformation that larger cut produces with very low cost.

Description of drawings

All pie graphs of the three-dimensional surface pick-up unit of Fig. 1 embodiments of the present invention;

The structured flowchart of the detailed structure of all pie graphs of Fig. 2 key diagram 1;

The process flow diagram of the Check processing of the three-dimensional surface pick-up unit of Fig. 3 embodiments of the present invention;

The schematic diagram of the curved surface shape spatial intensity distribution structured light of the three-dimensional surface pick-up unit of Fig. 4 embodiments of the present invention;

The embodiment of other of the projecting structural optical of Fig. 5 three-dimensional surface pick-up unit of the present invention;

The surface of Fig. 6 (a) expression measurand object does not have the intensity distributions schematic diagram in the situation of the change of shape such as indenture, (b) is the intensity distributions of the decoded result of (a);

There is the intensity distributions schematic diagram in the situation of the change of shape such as indenture in the surface of Fig. 7 (a) expression measurand object, (b) is the intensity distributions of the decoded result of (a).

Embodiment

Below, the embodiment with regard to three-dimensional surface pick-up unit of the present invention is illustrated by means of accompanying drawing.Fig. 1 is all pie graphs of the three-dimensional surface pick-up unit of embodiments of the present invention, and Fig. 2 is the structured flowchart of the detailed structure of all pie graphs of key diagram 1.

The three-dimensional surface pick-up unit of embodiments of the present invention shown in Figure 1, be the non-contact detection device of the 3 D defects such as a cut for detection of the surface of the measurand object X such as body of a motor car or other parts, indenture, it is comprised of following part: the light source 1 of linearity; For the light that guarantees linearity light source 1 can not shine directly into measurand object X, and between linearity light source 1 and measurand object X, arrange, can make the light of linearity light source 1 become equally distributedlight filter film 2 simultaneously; Take thephotographic means 3 of the image of measurand object X; Connect and control the computing machine 4 of linearity light source 1 andphotographic means 3.

Linearity light source 1 can use the general commodity in market circulation, is shaped as the ligthing paraphernalia of linearity such as daylight lamp, LED illumination etc.Light filter film 2 uses trnaslucent materials, makes the curve forms such as palace shape, tunnel-type, and it carries out dim light and diffusion to the light of linearity light source 1.A plurality of linearity light sources 1 are pressed certain arranged spaced along the curve form oflight filter film 2.

The transmittance oflight filter film 2 will be selected according to the light intensity oflinearity light source 2 and the surface reflection interest rate of measurand object, can select within 5% to 95% scope in general.Photographic means 3 can use various digital cameras, can select 8,10,12 or 16 bit digital cameras, the imageing sensors such as 3CCD, 1CCD, CMOS can be used, still camera, nonstatic image pickup device or video camera etc. can be used.

Computing machine 4 has the interface (in not expression of figure) that connects linearity light source 1 and photographic means 3, by the detection software (in not expression of figure) that weaves in advance, realize thatmnemon 10 shown in Figure 2, projection structurelight control unit 11,image photography unit 12,defect detection unit 13,size reckoning unit 14, testing result represent the various functions ofunit 15 andoutput unit 16.

Projection structurelight control unit 11 is controlled " opening " and the states such as " passes " of some linearity light sources 1, is the curved surface shape intensity distributions structured light of period profile along the curved surface oflight filter film 2 to form intensity, and to the measurand project objects.The various control data of projection structurelight control unit 11 employed control linearity light sources 1 also all are kept among themnemon 10.

Image photography unit 12 uses as photographing the ideal that detects usefulness and controls photographic means 3 to the needed the best achievement in cinematography parameter of image, takes the digital picture on the surface of measurand object X, and taken digital picture is input in the mnemon 10.This best achievement in cinematography parameter is included as the various optimal parameters (hereinafter to be referred as photographic parameter) that obtain the best needed camera of detection effect, also is kept in the memory storage 10.In addition,memory storage 10 also is used for preserving the various data such as result of aftermentioned unit simultaneously.

13 pairs of image photography unit, defect detection unit, 12 captured Digital Image Data are resolved, calculate measurand object X surface indenture, be accompanied by larger cut and the 3 D defects such as three-dimensional deformation that produce.Size calculates thatunit 14 utilizes the method for image analysis that the size (diameter, the degree of depth etc.) of detected 3 D defects is calculated.

Testing result representsunit 15, adopts the user to hold intelligible mode, and the information such as position, shape and size of detected defective are presented on the display of computing machine.In addition, it also has according to user's needs and provides the expansion of testing result or dwindle expression, all or part expression at displayscreen.Output unit 16 stores the information such as captured image photograph, testing result on the various media into image file, text, graphic file, form document, database mode, or is exported.

In addition, as shown in Figure 2, curved-surface structurelight projecting cell 5 is made of linearity light source 1 and projection structure light control unit 11.In addition, in order to generate needed projecting structural optical, the space between the integrated location of linearity projection light source 1 relation, each linearity light source and and light filter film between distance etc., all need to adjust in advance.

The below is to using the three-dimensional surface pick-up unit of present embodiment, and the process of the 3 D defects such as surface pitting of measurand object X partly being carried out Check processing is illustrated.Fig. 3 carries out the process flow diagram of Check processing for the three-dimensional surface pick-up unit that uses present embodiment.

Before this device of use detects, arrange linearity light source 1.When arranging, position, the interval between each linearity light source that at first will regulate linearity light source 1 are the distance (S101) between each linearity light source.Then regulate distance between each linearity light source 1 and thelight filter film 2, to improve as the generation curved surface shape needed hardware environment of intensity distributions structured light (S102).Above-mentioned setting only need to be implemented once when surface detecting system is assembled, and being not all needed to implement before each the detection.

During detection, at first the projection structurelight control unit 11 by computing machine 4 send instruction, control each linearity light source 1 " opening " and " pass ", generate to detect needed curved surface shape spatial intensity distribution structured light (S 103).Fig. 4 is the generation schematic diagram of curved surface shape spatial intensity distribution structured light, (a) be the intensity distributions schematic diagram of the configuration of linearity light source 1 and the structured light that around it, generates along the surface curve shape oflight filter film 2, (b) make the intensity distributions schematic diagram of the structured light behind the planar development (soon circular arc R linearize) for the curve form onlight filter film 2 surfaces that will (a).We can find out by Fig. 4 (b), and the intensity distributions of the structured light of the curved surface shape intensity distributions of Fig. 4 (a) namely becomes the sinusoidal wave shape intensity distributions after launching in the plane.That is the structured light of curved surface shape intensity distributions is actually a kind of sinusoidal wave shape intensity distributions structured light that has been bent.

Then, regulated the photographic parameter of photographic means 3 byimage photography unit 12 by computing machine 4, again by photographic means take measurand object X reflection curved surface shape intensity distributions structured light image and input to computing machine 4(S104).The intensity distributions of captured image is analyzed inimage photography unit 12, judges whether it can be as the ideal image that is used for defects detection., its intensity distributions enters next step handling procedure if being desirable, if its intensity distributions is also undesirable, that with regard to the photographic parameter of regulating again photographic means, take by the image of the curved surface shape intensity distributions structured light of image measurand object X reflection and carry out intensive analysis, until obtain (S105) till the image that ideal tensile strength distributes.

After obtaining desirable image, namely implement decoding by 13 pairs of these images in defect detection unit and process, its original curved surface shape intensity distributions sinusoidal wave shape structured light is transformed to linearity intensity distributions (S106).Do not have in the situation of the change of shape such as indenture on the surface of testee X, the intensity distributions of the image that is photographed will distribute for very regular sinusoidal wave shape as Fig. 6 (a), intensity distributions after decoding is processed will become straight line like this, shown in Fig. 6 (b).Yet if there is the change of shape such as indenture on the surface of testee X, the phase place of the intensity of indenture change of shape part will change on image, and the sinusoidal wave shape that also just can not get rule distributes, shown in Fig. 7 (a).Like this, after decoding is processed, there is the part of indenture change of shape will off-straight, shown in Fig. 7 (b).Therefore we just can conclude, exist the change of shape (S107) such as concavo-convex in the place of off-straight.

Size is calculated size dimension and the degree of depth ofunit 14 reckoning indentures.Shown in Fig. 7 (b), because the size of the scope of off-straight part and indenture is directly proportional, the degree of off-straight part is directly proportional with the degree of depth of indenture, so size calculates thatunit 14 calculates size dimension and the degree of depth (S108) of indenture according to the size of the scope of off-straight and degree.The result who detects can represent thatunit 15 is represented (S109) in graph image mode intuitively on the display of computing machine 4 by testing result, also can is kept at them on various storeies or be exported (S100) byoutput unit 16.

In the above-described embodiment, our structured light of the curved surface shape intensity distributions used has sinuous spatial intensity distribution.Projecting structural optical also can use the waveform with periodic spatial intensity distribution of other form, platform shape ripple as shown in Figure 5, square wave etc.

In the three-dimensional surface pick-up unit of present embodiment, detect the structured light of usefulness not directly to measurand object X projection, but first after the dim light bylight filter film 2 and the DIFFUSION TREATMENT again to the testee projection.Because projecting structural optical has passed through the above-mentioned processing oflight filter film 2, so even if for the stronger object of surperficial mirror-reflection, light source can directly not shone upon by body surface yet.We just can remove to take measurand object X as taking the object that does not have the surface mirror surface launching like this, and are easy to detect from taken image three distortion such as indenture on measurand object X surface.This processing only needs several seconds to tens seconds time usually.

Also have, project to the structured light on the measurand object X, be periodic intensity along the curve form of light filter film and distribute.For the reflected image of the structured light that photographs, by the decoding processing its curved surface shape intensity distributions is transformed to the linearity intensity distributions.Like this, there is the part of 3 D deformation defective on strength distribution curve, off-straight to be distributed on the measurand object X surface.Utilize this meaning characteristics, only need several seconds to tens seconds time just can simply detect the 3 D deformation defective.

The three-dimensional measuring apparatus of proposition of the present invention and method for three-dimensional measurement, the three-dimensional that is specially adapted to the surface configuration of the stronger object of surperficial mirror-reflection detects, such as the surface pitting of automobile and parts thereof and be accompanied by larger cut and the non-contact detecting of the three-dimensional deformation that produces.

Wherein, symbol description is as follows:

X measurand object

1 linearity light source

2 light filter films

3 photographic means

4 computing machines

5 curved-surface structure light projecting cells

10 storage unit

11 projection structure light control units

12 image photography unit

13 defect detection unit

14 sizes are calculated the unit

15 testing results represent the unit

16 output units.

Claims (4)

1. a surface configuration three-dimensional detection device is characterized in that having: the photographic means of taking the image of measurand object; Shroud and around above-mentioned measurand object, be set to curved light filter film; By the curved-surface structure light projecting cell of above-mentioned light filter film to above-mentioned measurand object projection curved surface shape structured light, this curved-surface structure light intensity is periodic distribution along the shape of above-mentioned curved light filter film; Defect detection unit, it carries out above-mentioned curved surface shape intensity distributions is transformed to the decoding processing of linearity intensity distributions to the image that photographs by above-mentioned photographic means, and then detects the 3 D defects of above-mentioned measurand body surface.

2. three-dimensional surface pick-up unit according to claim 1 is characterized in that described curved-surface structure light projecting cell has: several linearity light sources that configure along the curved surface of above-mentioned light filter film; The projection structure light control unit, the luminance of above-mentioned several linearity light sources of its control is the curved surface shape intensity distributions structured light that periodic intensity distributes to form along the surface configuration of above-mentioned light filter film.

3. three-dimensional surface pick-up unit according to claim 1 and 2 is characterized in that described curved surface shape intensity distributions structured light has sinusoidal wave shape, rectangle is wavy or platform shape is wavy periodic intensity distributes.

4. three-dimensional surface detection method, it is characterized in that: it sees through the light filter film with curve form that shrouds around the measurand object, to above-mentioned measurand project objects curved surface shape intensity distributions structured light, this curved surface shape intensity distributions structure light intensity is periodic distribution along the curved surface of above-mentioned light filter film; It uses above-mentioned photographic means to take above-mentioned measurand object, and to the processing of decoding of taken image, above-mentioned curved surface shape intensity distributions is transformed to the linearity intensity distributions, and then detects the 3 D defects that above-mentioned measurand body surface exists.

Images