CN203688463U - Transparent crystal foreign substance examination system - Google Patents

Abstract

The utility model discloses a transparent crystal foreign substance examination system. The transparent crystal foreign substance examination system comprises a first station and a second station, wherein the first station comprises a first camera, a second camera and a first plane light source, the first camera and the second camera go through a semi-transparent semi-reflective mirror at the same time and form images in parallel, and the first plane light source forms an image in a transmission light manner; the second station comprises a third camera and a second plane light source, the third camera is used for forming an image, and the second plane light source forms an image in a transmission light manner. According to the transparent crystal foreign substance examination system with three cameras provided by the utility model, transparent or semi-transparent crystal foreign substances can be accurately examined, so that the leak detection problem of transparent foreign substances when visual detection is utilized in industrial detection is effectively solved.

Description

Transparent crystal foreign matter detection system

Technical field

The utility model relates to industrial automation detection technique field, particularly a kind of transparent crystal foreign matter detection system.

Background technology

At present, the food safety management system of China advances fast, and the common people strengthen further for the degree of concern of food security, and the HACCP standard in Europe and the GB4927-91 standard of China have all proposed strict requirement to the detection of beer bottle empty bottle.In the production run of existing beer, beverage and medicine, all require container filling to meet corresponding quality standard, producing each step all needs to check, when defective bottle comes into the market, not only consumer may come to harm, and also can suffer damage for its economy of production producer and reputation.For the consideration of the aspect such as cost, environmental protection, beer, beverage industry generally adopt the filling mode of returnable bottle, after bottle reclaims through wash bottle, test after bottle again filling, labeling, coding, vanning, then come into the market to sell.In the bottle reclaiming under this mode, may there is various foreign matters, pollution, breakage, if do not clean up when wash bottle, and fail to be detected while testing bottle, may cause dirty bottle to come into the market.

Automatically testing a bottle detection field, generally adopting the method for vision, though with industrial camera to bottle to be detected photographic images one by one, then in analysis image, whether there is foreign matter or breakage, with judge this bottle whether qualified can carry out filling.And in the time there is transparent foreign matter in bottle, traditional visible detection method cannot be found, thereby cause foreign matter undetected, defective bottle comes into the market.Transparent foreign matter is generally crystal, can be divided into two classes: a class is the isotropic body take cullet as representative, such foreign matter often thickness is larger, and in the time of imaging, owing to reflecting and absorbing the shade that makes can clearly see foreign matter on image, such foreign matter loss is not high; The another kind of aeolotropic crystal for take adhesive tape as representative, this crystalloid transparency is high, thickness is little, and the conventional almost completely free method of imaging mode found, causes serious undetected.

For anisotropic transparent crystal, some colleges and universities and research institution of company are studied it, find that it has birefringent phenomenon, can under specific optical axis of crystal angle, utilize vision-based detection to be found by installing polariscopic mode additional.But in the middle of actual industrial production, the optical axis angle of foreign matter is random, require detection system all can be accurately under any angle of foreign matter, stablize, detected rapidly, when the optical axis angle of crystal is any, on image, all can find significantly foreign matter.To take station more few better for this detection system simultaneously.

Utility model content

(1) technical matters that will solve

The technical problems to be solved in the utility model is: in vision industrial detection field, transparent foreign matter is often difficult to be presented on significantly in image, therefore very easily causes undetected.The utility model proposes a kind of detection method for transparent crystal foreign matter, it adopts three industrial cameras to coordinate multi-disc linear polarizer to combine and detects, and improves the recall rate of transparent crystal foreign matter.

(2) technical scheme

For addressing the above problem, the utility model provides a kind of transparent crystal foreign matter detection system, comprise: the first station, comprise: first camera and second camera, described first camera and second camera are by semi-transparent semi-reflecting lens parallel imaging simultaneously, and, the first planar light source, it adopts the imaging of transmitted light mode; The second station, comprising: third phase machine, and for imaging, and, the second planar light source, it adopts the imaging of transmitted light mode.

Preferably, before every camera He on each light source, a slice linear polarizer is all installed, each polariscopic polarization direction is as described below: the polariscope on the first planar light source is 0 °, polariscope on the second planar light source is 45 °, polariscope before first camera is 0 °, polariscope before second camera is 45 °, and the polariscope before third phase machine is 45 °.

Preferably, in the time processing three cameras to the captured image of detected sample, if at least there is blackening or speck on piece image, and the clear-cut margin of blackening or speck, can determine on this sample and be attached with foreign matter.

(3) beneficial effect

Three camera detection of the transparent crystal foreign matter the utility model proposes can detect transparent or translucent crystal foreign matter exactly, have effectively solved the undetected difficult problem of transparent foreign matter while utilizing vision-based detection in industrial detection.

Accompanying drawing explanation

Fig. 1 is the structural representation according to the transparent crystal foreign matter detection system of the utility model embodiment;

Fig. 2 detects hourglass according to the employing one camera of the utility model embodiment to transparent crystal foreign matter to pick the schematic diagram of situation;

Fig. 3 detects hourglass according to the employing double double camera of the utility model embodiment to transparent crystal foreign matter to pick the schematic diagram of situation;

Fig. 4 detects hourglass according to the employing list station double camera of the utility model embodiment to transparent crystal foreign matter to pick the schematic diagram of situation;

Fig. 5 detects hourglass according to the detection system shown in employing Fig. 1 of the utility model embodiment to transparent crystal foreign matter to pick the schematic diagram of situation.

Wherein: A: the first station; B: the second station; 1: first camera; 2: second camera; 3: third phase machine; 4: the first planar light sources; 5: semi-transparent semi-reflecting lens; 6: the second planar light sources; P1, P2, P3, P4, P6: polariscope.

Embodiment

Below in conjunction with drawings and Examples, embodiment of the present utility model is described in further detail.Following examples are used for illustrating the utility model, but are not used for limiting scope of the present utility model.

As shown in Figure 1, the utility model embodiment provides a kind of transparent crystal foreign matter detection system, comprise: the first station A and the second station B, wherein, the first station A comprises: first camera 1 and second camera 2, and described first camera 1 and second camera 2 are passed through semi-transparent semi-reflecting lens 5 parallel imaging simultaneously, and, the first planar light source 4, it adopts the imaging of transmitted light mode; Wherein the second station B comprises: third phase machine 3, and for imaging, and, the second planar light source 6, it adopts the imaging of transmitted light mode.

Preferably, before every camera He on each light source, a slice linear polarizer is all installed, each polariscopic polarization direction is as described below: the polariscope P4 on the first planar light source 4 is 0 °, polariscope P6 on the second planar light source 6 is 45 °, polariscope P1 before first camera 1 is 0 °, polariscope P2 before second camera 2 is 45 °, and the polariscope P3 before third phase machine 3 is 45 °.

Preferably, in the time processing three cameras to the captured image of detected sample, if at least there is blackening or speck on piece image, and the clear-cut margin of blackening or speck, can determine on this sample and be attached with foreign matter.

Due to birefringent phenomenon, when light is when the aeolotropic crystal, generally can be decomposed into two-beam and along different direction refractions, and this two-beam is linearly polarized light, i.e. o light and e light.In the research category of this patent, because light source radiation modality is that transmitted light is vertically through transparent foreign matter, so can think that the light of light source is vertical incidence foreign matter.When light source send be linearly polarized light time, have following formula to set up:

If light is I through the light intensity after the polariscope before light source from light source sends, the light intensity of o light is I _o, the light intensity of e light is I _e, light source vibration plane and principal section of crystal angle are θ:

I _o=I sin ²θ

I _e=I cos ²θ (1)

And o light is mutually vertical with e polarisation of light direction, wherein e polarisation of light direction is along the optical axis direction of crystal, and o polarisation of light direction is perpendicular to the optical axis direction of crystal.

Known, when polarized light is by after crystal, its light intensity may change, and in the time that Crystal Rotation arrives different angles, the light intensity of transmission is not identical.

In addition, from Malus law, when light beam intensity is I ₁polarized light vertically by after becoming the polariscope at α angle with its polarization direction, the intensity of its transmitted ray is I ₂:

I ₂=I ₁cos ²α (2)

Think the light intensity through transparent crystal part that camera receives and the ratio γ of light intensity difference that does not pass through transparent crystal part _iabsolute value exceed certain ratio and can find foreign matter, that is:

${\mathrm{\γ}}_i=({\tilde{I}}^{\left(i\right)}-I^{\left(i\right)})/I^{\left(i\right)---\left(3\right)}$

I=1 in formula (3), 2,3.

If

|γ _i|≥40% (4)

Think that foreign matter can be detected.

Set forth respectively with regard to the system shown in Fig. 1 below.

(1) to the first planar light source 4 in Fig. 1, first camera 1, polariscope P4 and polariscope P1 part.When container is during at aeolotropic crystal, former incident light is divided into o light and e light.The light intensity that enters polariscope P1 and polariscope P2 after spectroscope is I/2.Because polariscope P4 and polariscope P1 are 0 °, two polariscopic polarization directions are parallel, so for this part α=0.If the o light intensity of the first station after polariscope P1 is

e light intensity is

the light intensity through transparent crystal foreign matter that first camera 1 receives is

be not I through the light intensity of transparent crystal foreign matter ⁽¹⁾, from formula (1):

$\begin{array}{c}{I}_o^{\left(1\right)}=I_o{\sin }^2\mathrm{\θ}/2=I{\sin }^4\mathrm{\θ}/2\\ I_e^{\left(1\right)}=I_e{\cos }^2\mathrm{\θ}/2=I{\cos }^4\mathrm{\θ}/2\\ {\tilde{I}}^{\left(1\right)}=I_o^{\left(1\right)}+I_e^{\left(1\right)}=I({\cos }^4\mathrm{\θ}+{\sin }^4\mathrm{\θ})/2\\ I^{\left(1\right)=I/2}\end{array}---\left(5\right)$

Can obtain through deriving:

${\mathrm{\γ}}_1=({\tilde{I}}^{\left(1\right)}-I^{\left(1\right)})/I^{\left(1\right)}={\cos }^4\mathrm{\θ}+{\sin }^4\mathrm{\θ}-1---\left(6\right)$

| γ ₁| with the pass of θ be shown in Fig. 2.Wherein horizontal ordinate is Crystal Rotation angle, i.e. incident polarized light vibration plane and principal section of crystal angle, and ordinate is the light intensity through transparent crystal part that receives of camera and do not pass through the absolute value of ratio of light intensity difference of transparent crystal part | γ ₁|.Under crystal different rotary angle, can sensing range mark in Fig. 2.Can find, in the time using a camera, will have the undetected of greater probability.

(2) the part system forming for the first light source 1, the second planar light source 2, first camera 1, third phase machine 3, polariscope P4, polariscope P1, polariscope P6 and polariscope P3 in Fig. 1.If transparent crystal foreign matter self does not rotate in the time of 2 stations, establishing the first station A Crystal Rotation angle is θ, and the second station B Crystal Rotation angle is θ ', order:

θ′=θ+45° (7)

If the o light intensity of the second station B after polariscope P3 is

e light intensity is

the light intensity through transparent crystal part that third phase machine 3 receives is

be not I through the light intensity of transparent crystal part ⁽³⁾.

Because the first station A is identical with the structure of the second station B, so from formula (6):

${\mathrm{\γ}}_3=({\tilde{I}}^{\left(3\right)}-I^{\left(3\right)})/I^{\left(3\right)}={\cos }^4{\mathrm{\θ}}^{\′}+{\sin }^4{\mathrm{\θ}}^{\′}-1---\left(8\right)$

Easily known γ by formula (6) and formula (8) ₁and γ ₃the cycle changing with θ is 90 °.In the time of two station parallel detections, there is a camera calibration to think and be detected to transparent foreign matter.Work as

max{|γ ₁|，|γ ₃|}≥40%

Time foreign matter can detect.Formula (7) both can be realized by polariscope P3 and polariscope P6 rotation, also can be realized by body rotation.Now first camera 1 | γ ₁| and third phase machine 3 | γ ₃| with the pass of θ be shown in Fig. 3.

Analysis chart 3 curves are easily known, work as θ ₁with θ ₂differ half period, 45 ° time, loss is minimum.

As can be seen from Figure 3, after employing double camera serial detection architecture, the loss of transparent crystal foreign matter is had to larger reduction compared with 1.

(3) in the time that detection system is as shown in the first station A in Fig. 1.It is identical with the light path of second camera 2 that the first planar light source 4 arrives first camera 1, and in the time that all polariscopes are not installed, first camera 1 is identical with the imaging results of second camera 2.

If the o light intensity after polariscope P2 is

e light intensity is

the light intensity through transparent crystal foreign matter that second camera 2 receives is

be not I through the light intensity of transparent crystal foreign matter ⁽²⁾.Polariscope P2 is α with respect to the rotation angle of polariscope P4.

From formula (2):

$\begin{array}{c}{I}^{\left(2\right)}=I{\cos }^2\mathrm{\α}/2\\ I_o^{\left(2\right)}=I_o{\sin }^2(\mathrm{\θ}-\mathrm{\α})=I{\sin }^2\mathrm{\θ}{\sin }^2(\mathrm{\θ}-\mathrm{\α})/2\\ I_e^{\left(2\right)}=I_e{\cos }^2(\mathrm{\θ}-\mathrm{\α})=I{\cos }^2\mathrm{\θ}{\cos }^2(\mathrm{\θ}-\mathrm{\α})/2\\ {\tilde{I}}^{\left(2\right)}=I_o^{\left(2\right)}+I_e^{\left(2\right)}=[{\sin }^2\mathrm{\θ}{\sin }^2(\mathrm{\θ}-\mathrm{\α})+{\cos }^2\mathrm{\θ}{\cos }^2(\mathrm{\θ}-\mathrm{\α})]I/2\end{array}---\left(9\right)$

Can obtain through deriving:

${\mathrm{\γ}}_2=\frac{{\tilde{I}}^{\left(2\right)}-I^{\left(2\right)}}{I^{\left(2\right)}}=\frac{{\sin }^2\mathrm{\θ}{\sin }^2(\mathrm{\θ}-\mathrm{\α})+{\cos }^2\mathrm{\θ}{\cos }^2(\mathrm{\θ}-\mathrm{\α})}{{\cos }^2\mathrm{\α}}-1---\left(10\right)$

Now first camera 1 | γ ₁| and second camera 2 | γ ₂| with the pass of θ be shown in Fig. 4.Wherein the implication of horizontal ordinate and ordinate is identical with Fig. 2, Fig. 3.

When

max{|γ ₁|，|γ ₂|}≥40%

Time think that foreign matter can be detected.

Analysis chart 4 is known, and in the time of α=45 °, transparent crystal foreign matter loss is minimum, and than adopting, the loss of detection method of one camera is low, but still exists significantly undetected.

(4) when adopt shown in Fig. 1 complete system time, the above analysis is known, first camera 1 | γ ₁|, second camera 2 | γ ₂| and third phase machine 3 | γ ₃| with the pass of θ be shown in Fig. 5.Wherein the implication of horizontal ordinate and ordinate and Fig. 2, Fig. 3, Fig. 4 are identical.

In like manner, when

max{|γ ₁|，|γ ₂|，|γ ₃|}≥40%

Time think that foreign matter can be detected.

Analysis chart 5 is known, in the time that the structure that adopts three-phase series-parallel machine as shown in Figure 1 to combine detects, can in theory loss be down to 0, can reach the requirement of commercial Application.

Known by above-mentioned analysis, in the time adopting the system shown in Fig. 1 to detect transparent crystal foreign matter, can stablize and exactly the type foreign matter is effectively detected.Table 1 is three cameras captured image under θ different angles in the system shown in Fig. 1 in the time that bottle bottom has been pasted adhesive tape, as can be seen from Table 1, adopt the structure shown in Fig. 1, no matter θ is under arbitrarily angled, all can have to be no less than a captured image of camera and can significantly transparent crystal foreign matter to be detected.

In sum, the utlity model has following some advantage:

1. loss is low.Adopt the detection system that proposes of the utility model to detect transparent crystal foreign matter, can the clear existence of finding significantly foreign matter in image, recall rate is 100% in theory, actual recall rate is higher than 99%.

2. false drop rate is low.Performance difference when existing and not having transparent crystal foreign matter in image is obvious, so be difficult for forming flase drop.

3. take station few.Only using 2 stations to realize detects the high-accuracy of transparent crystal foreign matter.

4. computing velocity is fast.In the time there is transparent crystal foreign matter, in image, performance obviously, can be used simple gray scale and edge detection method both can rapidly and accurately foreign matter be distinguished, so computation complexity is low, computing velocity is fast.

5. applied widely.The system that the utility model proposes can all can detect effectively to all bilinearity crystal, as adhesive tape, cigarette film, kalzit, quartz, mica etc.And for the glass material of bottle itself, because it has the characteristic of isotropic, so can not be affected in native system.

6. site installation test is convenient.By the angle index on polarization mirror holder, or directly can quickly and easily each polariscope be adjusted to the angle needing by polarization characteristic, the angle of required adjustment is 0 ° or 45 °, and system is not high to angular setting accuracy requirement, so debug at the scene more for convenience.

7. can detect opaque foreign body simultaneously.This system is in detecting transparent foreign matter, can compatiblely detect opaque foreign body, after the system that equipment is proposed at installation the utility model, needn't the detection system for shooting area opaque foreign body be additionally installed again, greatly save equipment cost and space hold.

Description to the utility model specific embodiment in conjunction with the drawings, other side of the present utility model and feature are apparent to those skilled in the art.

The above is only preferred implementation of the present utility model; should be understood that; for those skilled in the art; do not departing under the prerequisite of the utility model know-why; can also make some improvement and replacement, these improvement and replacement also should be considered as protection domain of the present utility model.

Claims (2)

1. a transparent crystal foreign matter detection system, is characterized in that, comprising:

The first station, comprising: first camera and second camera, and described first camera and second camera are passed through semi-transparent semi-reflecting lens parallel imaging simultaneously, and, the first planar light source, it adopts the imaging of transmitted light mode;

The second station, comprising: third phase machine, and for imaging, and, the second planar light source, it adopts the imaging of transmitted light mode.

2. system according to claim 1, it is characterized in that, equal hookup wire polariscope before every camera and on each light source, each polariscopic polarization direction is as described below: the polariscope on the first planar light source is 0 °, polariscope on the second planar light source is 45 °, polariscope before first camera is 0 °, and the polariscope before second camera is 45 °, and the polariscope before third phase machine is 45 °.

Images