Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/14—Measuring arrangements characterised by the use of optical techniques for measuring distance or clearance between spaced objects or spaced apertures
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B11/00—Measuring arrangements characterised by the use of optical techniques
  • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
  • G01B11/25—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. one or more lines, moiré fringes on the object
  • G01B11/2518—Projection by scanning of the object
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T7/00—Image analysis
  • G06T7/0002—Inspection of images, e.g. flaw detection
  • G06T7/0004—Industrial image inspection
  • G06T7/001—Industrial image inspection using an image reference approach
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T2207/00—Indexing scheme for image analysis or image enhancement
  • G06T2207/30—Subject of image; Context of image processing
  • G06T2207/30108—Industrial image inspection

Definitions

• the subject of the present invention is a method for registering an article and retrieving a portion of the article.
• Automation in the manufacture and processing of many industrial goods and commodities requires automated recognition and recovery of items and / or portions of items.
• the laid-open specification DE3704313A1 deals, for example, with a non-contact optical method for detecting an object.
• a hologram is attached to the object.
• the hologram is illuminated with coherent light and the radiation returned by the hologram is captured by a camera. From the radiation returned, conclusions can be drawn about the type of object, its position in space, shape changes and the dynamic behavior.
• a disadvantage of the method is the need for an aid (hologram), which must be attached to the object.
• the method is therefore not applicable to objects that can not be provided with appropriate tools.
• an item would need to be provided with a variety of holograms to recognize and retrieve different portions of the item.
• Properties of objects in particular the surface structure of an object, provide features for a unique detection and / or recovery of portions of the object.
• a first subject of the present invention is thus a method for registering an object, characterized in that a portion of the object is scanned with electromagnetic radiation and at least a part of the emitted from the object as a result of scanning electromagnetic radiation collected and the obtained scanning signal, optionally to S signal ver arb processing, stored together with other parameters to individual sections of the article in the form of a reference profile in a database, wherein the electromagnetic radiation used for scanning has a line-shaped beam profile.
• a further subject of the present invention is a method for the detection and / or recovery of a portion of an object, comprising the steps:
• Scanning signal optionally using signal processing methods, wherein the electromagnetic radiation used for scanning has a linear beam profile
• a further subject of the present invention is a method for associating a portion of a processed object with the corresponding portion of the unprocessed article, comprising the steps of:
• the present invention can be formally divided into two phases.
• a first phase - hereinafter also referred to as the first phase - an object is registered.
• a reference profile is created, which is stored in a database.
• the reference profile contains information about intrinsic structural properties of the object and the positions of the object where the intrinsic structural properties occur.
• the reference profile thus represents a kind of map of the object, on which information about intrinsic structural characteristics as a function of the place is recorded.
• the reference profile contains parameters for individual sections of the article. In the reference profile, these parameters are listed together with the information about the intrinsic structural properties of the object. This means that in the reference profile for individual sections, which are identified by one or more parameters, information about the intrinsic structural properties of the object are present in these sections.
• the parameters indicate certain features on the map, such as lighthouses.
• defects such as scratches or inclusions occur in the manufacture and processing of an article. Furthermore, it is conceivable that these defects can not be eliminated immediately, for example, because an immediate elimination would mean the interruption of the manufacturing or processing process.
• these defects are first detected.
• the article is scanned by electromagnetic radiation to produce a characteristic scan signal that is so characteristic of individual sections of the article that these sections can later be uniquely retrieved. From the scanning signal, a reference profile is generated.
• the reference profile records the areas where defects have occurred. It can also be recorded, what kind of flaws it is.
• Such information about the defects is generally referred to herein as a parameter.
• the defects can be detected, for example, with online analysis methods. If it is visually detectable defects, it is also conceivable that they are directly detectable in the scanning signal, so that it is possible to dispense with a further analy s ever driving. Scratches on an adjacent surface Whether it is a surface or a surface, it is preferable for the device to be scanned with electromagnetic radiation, for example, a clearly recognizable signal.
• the defect is to be recovered, for example, to eliminate them.
• a portion of the object is determined in which the defect occurs. This portion of the item is rescanned to create a local profile. By comparing the local profile with the portion of the reference signal having the missing parts, it is possible to check whether the correct portion of the object is present.
• This comparison corresponds to a verification; a check is made as to whether the section identified in the reference profile and having a specific feature (defect) actually exists where indicated by the reference profile.
• the comparison between the local profile and the identified section of the reference profile reveals that the previously determined location, which should have a certain feature, is actually in the area for which a local profile has been created. So is the determined A location having a certain feature actually located on the object may be followed by further steps, such as the elimination of imperfections.
• the allocation can identify the errors in the determination of the location and the correct area that determines the particular location Should be determined again.
• the second phase may be used, for example, to associate a portion of a split item with the corresponding portion of the undivided item.
• the unused item corresponds to the above-mentioned unprocessed item; the divided article corresponds to the above-mentioned machined article.
• unprocessed and processed are intended to mean that the object has been subjected to any processing between the registration in the first phase (unprocessed state) and the re-sampling in the second phase, which does not necessarily lead to a change of the object ,
• the processing can therefore for example be a storage.
• the processing is a process in which the subject has undergone a change.
• a reference profile to the undivided object is initialized.
• the object is then divided into several parts.
• the local profile is compared with the reference profile section by section to be able to assign the local profile to a section of the reference profile. The assignment determines where the part was previously in the undivided counterpart.
• the electromagnetic radiation during detection and identification has a line-shaped beam profile.
• the scanning of a portion of the object in the two phases is preferably done in the same manner to achieve high reproducibility.
• the area scanned in the first phase is also referred to here as the first area, the area scanned in the second phase as the second area.
• the second region is usually within the first region or overlaps at least partially with it, so that an association between the local profile and a section of the reference profile is even possible.
• the section of the reference profile is understood to be a contiguous part of the reference profile that is smaller than the reference profile itself.
• the relative movement between the object and the incident beam may be performed so that the object moves and the radiation source is held, or carried out so that the radiation source moves and the item is being held. It is also conceivable that both the object and the radiation source moves. It is also conceivable that the object and the radiation source are held fast and the scanning beam is guided over a region of the object, for example by means of movable mirrors.
• the relative movement can take place continuously with constant wind speed, accelerating or decelerating, or discontinuously, ie, step-by-step. Preferably, the movement is carried out at a constant speed.
• the scanning is done with electromagnetic radiation rather.
• the wavelength of the electromagnetic radiation used depends on the respectively present intrinsic structural properties of the object. Depending on the nature of the intrinsic structural properties, a particular wavelength range may be advantageous because, for example, it leads to particularly strong signals. It is conceivable to determine the optimum wavelength range empirically. Usually, visible to infrared light is used.
• the electromagnetic radiation used may be coherent or non-coherent, depending on whether interference phenomena such as speckle patterns are useful or disturbing to generate a reference profile.
• interference phenomena such as speckle patterns are useful or disturbing to generate a reference profile.
• the intrinsic structural properties of the object, which are supposed to produce a characteristic signal upon irradiation, are decisive for the
• LED light emitting diode
• Methods for the reduction of speckle appearance in coherent radiation are known in the art (see for example DE102004062418B4). It is also conceivable to use LED arrays, ie an arrangement of several LEDs.
• the recording of the characteristic radiation emanating from the object takes place in reflection or transmission. It is also conceivable that the recording takes place in reflection and transmission. Since most objects are intransparent to electromagnetic radiation over a wide range of wavelengths, the recording of the characteristic radiation emanating from the object usually takes place in reflection. For the sake of simplicity, only the reflection variant is explained in more detail in the present description; However, the method according to the invention is not limited to the absorption of radiation in reflection but also includes the absorption of radiation in transmission. The person skilled in the art knows how to modify the method described in more detail here in order to record radiation in transmission.
• the surface of the article is scanned using a focused beam of light.
• the beam is focused on the surface, for example, by means of a lens. If one were to focus the beam at one point and pass that point across the surface of the object to produce a reference profile in the first phase, then in the second phase one would have to find the area that the point had sampled in the first phase, which, as should be immediately apparent, is very difficult due to the small extent of the scanned area.
• a line-shaped beam profile is used for scanning, in which the beam profile is widened transversely to the scanning direction.
• the beam sweeps over a larger area in a single scan than when using a point-shaped beam profile, and this larger area can be re-hit and at least partially rescanned later on.
• Scanning with a linear beam profile is more akin to averaging over a plurality of scanning signals resulting from scanning with a point beam profile along a plurality of closely spaced and parallel lines. It is surprising that this averaging generates a reference profile over a wide range which is so characteristic of individual sections of the article that the individual sections can later be clearly identified.
• a linear beam profile is defined here as follows: Usually, the intensity in the cross-sectional center of the radiation is highest and decreases toward the outside. The intensity can decrease evenly in all directions - in this case there is a round cross-sectional profile. In all other cases there is at least one direction in which the intensity gradient is greatest and at least one direction in which the intensity gradient is smallest.
• the beam width is understood as meaning the distance from the center of the cross-sectional profile in the direction of the smallest intensity gradient, at which the intensity has dropped to half of its value in the center.
• the beam thickness is understood to be the distance from the center of the cross-sectional profile in the direction of the highest intensity gradient, at which the intensity has dropped to half of its value in the center.
• a line-shaped beam profile refers to a beam profile in which the beam width is increased by a factor of more than! 0 is greater than the beam thickness.
• the beam width is larger than the beam thickness by a factor of more than 50, more preferably by a factor of more than 100, and most preferably by a factor of more than 150.
• the jet thickness is in the range of the mean groove width of the present surface (for the definition of the average groove width, see DI EN ISO 4287: 1998).
• the abovementioned ranges for the beam thickness and the beam width are very well suited for achieving, on the one hand, the positioning that is sufficiently accurate for reproducibility and, on the other hand, for a sufficiently accurate assignment of the local profile to achieve a sufficient signal-to-noise ratio for a section of the reference profile.
• the recording of the characteristic radiation emanating from the object takes place with the aid of one or more detectors. Common detectors are camera, photodiode or phototransistor.
• the radiation source, the object and one or more detectors may be arranged in different ways to one another.
• the scanning beam preferably falls perpendicular to the surface of the article ( Figure 4).
• One or more detectors are preferably arranged laterally of the scanning beam in order to absorb diffusely reflected (scattered) radiation.
• a corresponding sensor with which this embodiment of the method according to the invention can be carried out is described, for example, in the publication WO2010 / 1 18835 (A1) or the application DE 102010015014.2, the content of which is to be incorporated by reference into this description.
• the scanning beam preferably falls obliquely, ie at an angle of incidence in the range of 10 ° to 80 °, more preferably in the range of 20 ° to 70 ° and especially preferably in the range of 30 ° to 60 ° relative to the normal of the surface of the article to this.
• Specularly reflected radiation is returned by the object according to the law of reflection at an angle of reflection corresponding to the angle of incidence.
• One or more detectors are preferably laterally from the fall angle in an angular range of 5 ° to 30 ° relative to the angle of failure arranged (Fig. 1).
• a corresponding sensor with which this embodiment of the method according to the invention can be carried out is For example, in the publication WO2010 / 040422 (A1) or the application DE102009059054.4 described, the content of which is incorporated by reference into this description.
• a signal is generated from the collected radiation, which is also referred to here as a scanning signal.
• a reference profile or a local profile is generated from the scanning signal.
• scanning The process of irradiating a portion of the object with relative movement of the object and the beam impinging on the object, and capturing a portion of the incident radiation emanating from the object as a result of the irradiation is collectively referred to herein as scanning.
• the relative movement between the object and the scanning beam can be constant or discontinuous.
• the incoming radiation at the sampling on the detector is detected and digitized at a discrete and constant sampling frequency.
• the sampling signal is thus usually an intensity-time function. If a region of the object is scanned at a constant speed, there is a linear relationship between the time of recording an intensity value and the location of the object at which the respective intensity value has occurred during irradiation, so that the intensity-time function can be easily calculated an intensity-location function can be calculated.
• the relative movement between the object and the scanning signal is not constant, the result is a correspondingly more complex relationship between the intensity-time function and the intensity-location function.
• a transformation function must be known. Here can be used on the known from the prior art coding.
• markers with a constant spacing of 300 microns are used to transform the intensity-time signal into an intensity-location signal (see WO05 / 088533A1 page 23). These markers are optically detected with a separate photodetector. Since the constant measuring frequency (sampling rate) and the distance of the markings are known, the location at which the focused scanning beam was located can be determined at any time. This makes it possible to transform the time-dependent scanning signal with the aid of the coder into a time-independent intensity-location signal. For some items, no markings need to be applied because they have a consistent ripple that can be used to correlate time to place (see, for example, application DE 102010021380.2).
• the reference profile and the local profile are generated from the sampling signal by various mathematical methods such as filtering and / or background subtraction or other other methods of signal processing.
• filtering and / or background subtraction or other other methods of signal processing By means of these mathematical methods, for example, random or systematic fluctuations resulting from individual measurements are largely eliminated.
• parameters are added to individual sections of the article in the reference profile. It is also conceivable to include further information on the object in the reference profile, such as, for example, batch numbers, identification numbers, images, property parameters and the like.
• the reference profile is stored in a database in order to be able to use it at a later time (in the second phase), the term database generally being to be understood as a data or information store.
• the storage may be on, for example, an electronic storage medium (semiconductor memory), an optical storage medium (e.g., compact disk), a magnetic storage medium (e.g., hard disk), or other information storage medium. It is also conceivable to store the signature as an optical code (barcode, matrix code) on a paper or the object itself or as a hologram. After the reference profile has been generated and saved, the respective object is registered.
• the item is scanned again.
• a smaller range is sampled in the second phase than in the first phase.
• the local profile is compared with one or more sections of the reference profile, around that section of the reference profile or to verify that a local profile is identical to a given portion of the reference profile.
• FIG. 1 shows schematically the method according to the invention for scanning the surface I of an object.
• An area 7 of the surface 1 is irradiated by means of a source 2 for electromagnetic radiation.
• a portion of the reflected radiation 4 is picked up by a detector 5 to pick up a sample signal.
• the object is moved relative to the array of radiation source 2 and detector 5 (represented by the thick black arrow).
• a line-shaped beam profile 6, whose longer extension is transverse to the direction of movement.
• the sub-figures 2 (a) and 2 (b) illustrate a line-shaped beam profile with a beam width SB and a beam thickness SD.
• sub-figure 2 (a) the two-dimensional cross-sectional profile of a elektr omagnetis chen beam is shown in the focal point. At the center of the cross-sectional profile is the highest intensity. The intensity / decreases to the outside, where there is a first direction (x), in which the intensity decreases the most with increasing distance A to the center, and a further direction (y), which is perpendicular to the first direction (x), in which the intensity decreases the weakest with increasing distance A to the center.
• Sub-figure 2 (b) shows the intensity profile / as a function of the state A from the center.
• the beam width and the beam thickness are defined as those distances from the center in which the intensity has dropped to 50% of its maximum value in the center, here the beam width in the j'-direction and the beam thickness in the x-direction.
• FIGS. 3 (a) and 3 (b) show by way of example how a line-shaped beam profile can be generated with the aid of a plano-convex cylindrical lens 300.
• the cylinder lens 300 acts in one
• R is the cylinder radius and n is the refractive index of the lens material.
• Figure 4 shows a preferred arrangement for scanning an article in which scanning beam 3 falls perpendicular to the surface of the article.
• Figures 5a, 5b and 5c show scanning signals resulting from the scanning of an object with a linear beam profile.
• the scanning signal was recorded in each case with a sensor according to the application DE102009059054.4
• the ordinate in each case shows the voltage signal I (in arbitrary units) of the photodetector used, which is proportional to the intensity of the incident radiation.
• the abscissa shows the distance X traveled in the scan along a single line in cm.
• a single photodetector was used in the second feedthrough (12).
• the scanned article was a composite consisting of the special paper 7110 from 3M (3M 7110 litho paper, white) and a laminated protective film PET Overlam RP35 from UPM Raflatac.
• the radiation source used was a Speckie-reduced laser diode (Flexpoint line module FP-HOM-SLD, Laser Components GmbH).
• the beam profile was linear, with a beam width of 5 mm and a beam thickness of 25 ⁇ .
• the scanning signals can be stored directly as reference profiles.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Quality & Reliability (AREA)
• Theoretical Computer Science (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
• Length-Measuring Devices Using Wave Or Particle Radiation (AREA)

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• 2010
  • 2010-12-13 DE DE102010062959A patent/DE102010062959A1/de not_active Withdrawn
• 2011
  • 2011-12-08 JP JP2013543651A patent/JP2014504367A/ja active Pending
  • 2011-12-08 US US13/990,758 patent/US20130250310A1/en not_active Abandoned
  • 2011-12-08 CA CA2821066A patent/CA2821066A1/en not_active Abandoned
  • 2011-12-08 AU AU2011344400A patent/AU2011344400A1/en not_active Abandoned
  • 2011-12-08 BR BR112013013105A patent/BR112013013105A2/pt not_active IP Right Cessation
  • 2011-12-08 CN CN2011800596796A patent/CN103261837A/zh active Pending
  • 2011-12-08 KR KR1020137015112A patent/KR20130141590A/ko not_active Application Discontinuation
  • 2011-12-08 RU RU2013132141/28A patent/RU2013132141A/ru not_active Application Discontinuation
  • 2011-12-08 EP EP11801660.9A patent/EP2652440A1/de not_active Withdrawn
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