DE3521357A1 - Method and device for optimising image-processing systems in textile and leather processing - Google Patents

Abstract

The invention relates to a method for optimising image-processing systems for flat workpieces with regular or irregular boundaries, of textiles, leather, plastics, metals or natural materials, and a device for carrying out the method. It is characterised by the fact that a workpiece is treated with a contrast medium from the inside or outside, that the workpiece is excited by a medium radiated onto it or any other field effect in order to output a signal of a particular characteristic which can be detected by measuring techniques, and the signal is conducted to a receiver or receiver matrix which are only sensitive to the output reaction and, by automatically converting the signal, are capable of displaying or evaluating an image or particular characteristics of the object. It is therefore suitable for providing for simpler image processing and also for significantly extending the limits of the prior art even to cope with difficult problems. Only a small equipment expenditure is necessary and the contrast medium can be applied efficiently in previous work stages. At the same time, it is also possible to achieve better visual monitoring of the process control by humans with UV illumination with a suitable form of the contrast medium, for example fluorescine.

Description

Method and device for optimizing image processing

Systems in textile and leather processing The invention relates to a method for optimizing image processing systems for flat workpieces with regular or irregular borders, made of textiles, leather, plastics, Metals or natural substances, as well as a device for carrying out the method.

In the course of the use of industrial robots and flexible machines In large parts of the industry, automatic image processing is an important one Become a key technology. In J. Bretschi "Intelligent measuring systems for automation technical processes published by R. Oldenburg Verlag Munich, Vienna 1979 numerous methods of image processing are described. Then there are the following options known from image generation for image processing - color images - gray value images - binary images - contour images.

The natural human environment is presented in the form of a Color image. In the industrial sector, the possible color palette is limited, However, their processing still represents a very high level of difficulty. For this purpose, three gray value images have to be processed in the processing stage of the sensor corresponding to the color separations red, green and blue. These three pictures are to be processed at the same time due to time constraints. Because of the high degree of difficulty however, if the processing of color images has not yet been carried out, this would be particular in textile processing desirable.

Gray value images have i. a. between 32 and 256 gray values. as a typical example of a gray value scene is referred to here on black and white photos. You can see that separating the individual objects is very difficult. In In practice, there are further aggravating problems due to disturbances due to soiling, Rust, reflections of the light, etc. added. That is why gray value images are currently being used rarely processed in industrial applications.

It is much easier to use binary images. You wise only the two degrees of quality "white" and "black".

If you reduce these images to those object edges where If the brightness value changes, a contour image of the object is obtained.

To generate a binary image, the object is replaced by a corresponding The lighting clearly stands out from the background. There are two ways of doing this on: - transmitted light - incident light.

An example of the transmitted light method is one that is illuminated from below Conveyor belt on which the workpieces are guided past the sensor of a sewing machine.

In the case of incident light, a distinction is made between diffuse and directed Lighting. The diffuse incident light corresponds to the daylight illumination and is technically achieved through large-area light sources.

If one observes exactly in the direction of incident light The direction given by the law of reflection (glancing angle), so are surfaces different color shiny in the same way. Even black parts. appear then bright (brightfield observation).

Disturbances in the surface, e.g. holes in leather, reflect this Not light and can be seen as dark areas in the image field.

When observing the dark field, the object is at one of the glancing angles clearly different angles observed.

Disturbances of the image surface are based on the generated scattered light award.

As a rule, the background can be found in industrial practice Do not change the object to be optically detected at will. One example Workpiece clamped in an automatic sewing machine stands out only poorly from the background the processing machine, which is also often heavily affected by dust, sections, etc. is dirty.

There is then one possibility of improving object recognition in illuminating the background with monochromatic light (e.g. sodium vapor lamp). A mounted in front of the television camera and tuned to the wavelength of the light source, narrow-band filter makes the background appear light and the object appear dark.

Another way to simplify a picture scene is to Generation of a light section image. These images are a special case of binary images. They are distance images of the observed scene and are created by opening a gap or slits are projected onto a scene.

The described options for image generation and image processing therefore use all the primary properties of a workpiece the image of these properties and filter them by optical or electronic methods the properties relevant for the respective process out subsequently, with what the known image processing systems are very complex and expensive and thus rarely go beyond laboratory studies. This one Disadvantage wants the inventive method to remedy this by as early as possible Step an image data reduction and selection is sought to thereby the image processing to simplify and optimize. It should be color images, gray value images, binary images and contour images are already generated on the workpiece, which the electronics use for evaluation is significantly relieved and the image data processing input on a broad basis can find in automation.

According to the invention the object is achieved in that the respective Workpiece is treated with a contrast agent from the outside or inside. This contrast medium is generated by an irradiated medium or some other field effect stimulated to emit a metrologically detectable signal of certain property. This is forwarded to a recipient or a recipient matrix that is only used for the response given is sensitive and is now capable of conversion a picture or certain properties of the workpiece or object must be shown and evaluate.

Thus, Figure 1 shows an arrangement according to the invention consisting of the Workpiece 1, for example, a piece of clothing that only has two edges 2 and 2 'has been treated with a contrast agent 9. This contrast agent will For example, sprayed on in an upstream process such as cutting or pressed on and consists preferably of yellow-red, green or blue fluorescent Flourescin or another stimulable substance that is normally invisible.

For certain workpieces such as body parts, this is sufficient Luminous paint, because this contrast medium is used again in a subsequent painting process is covered. Magnetizable particles on non-metals are also conceivable can be applied in a water-soluble manner. A medium 3 is applied to the workpiece only z. B. a UV light or a magnetic field via a selective converter 4 on the On the transmitter side as well as the transmitter 5, the workpiece 1 and the treated ones radiate edge 2 and 2 a different and clearly distinguishable signal or medium 6 to the transducer on the receiver side 7 and to the receiver 8, which is now for image processing and analysis can be used. Processing in the recipient is now limited to the simple distinction between two characteristics, whereby depending on the treatment of the Workpiece with the contrast agent immediately a reduced color image, a reduced Gray image or just a binary image or contour image results. The background is playing it no longer matters because it has not been treated with a contrast agent, black objects can therefore be detected by a sensor or a sensor assembly on a black background or colored objects on a colored background selectively separate. The designation image and color is only used as an alternative to the Principle using the example of the contrast agent flourescin, known as optical brightener, to make recognizable. Of course, for another contrast agent, from Workpiece - structure or field strength-differentiated can be spoken.

In Figure 2 is an example of the possibilities there to apply the contrast agent to generate contrast differences. Man can only apply the contrast agent to an edge after 1o, which is a simple one two-valued sensor can distinguish the edge.

At 11, a contour image is created by applying during punching or cutting where, however, at 12 a grid in the form of a coordinate system or at 13 a coordinate system with points is sprayed or printed. At 14 and 15 is proposed by a contrast agent A and B different contrasts and to combine forms of application with one another. Where, on the other hand, at 15 the entire Workpiece surface treated with the contrast agent is a so-called binary image to create. Here, for example, in the manufacture of semi-finished products or in a the contrast agent in the entire workpiece surface prior to the work process be applied.

FIG. 3 shows an application according to the invention in a simple one Refer to edge control. A sewing machine is shown with a so-called Y light guide guides the W light to the impregnated edge 18, from the transmitter 20 and receiver 21. Sufficient contrast to workpiece 19 is thus achieved. This application can be used in simple sewing machines as well as in automatic sewing machines.

The use in leather processing is described in FIG. at the leather control on a light table 22 will show a piece of leather 23 and a defect / hole 25 marked with brightener on the edges. At a subsequent workstation the contrast agent is excited by the transmitter 5 via transducer 4 and medium 3 and by the video camera or sensor 26 recorded via converter optics 27. It can now an error localization and area determination carried out on the basis of the contour images will. A computer is now also able to e.g. insert soles into the piece of leather take into account that the waste is minimal.

Another embodiment is shown in Figure 5. There the method and the device according to the invention for controlling a loading and sewing robot 31 used. According to FIG. 16, the fabric blank 29 is flat with a contrast medium treated. The recognition system 32 issues positioning commands to the robot 31 and the robot automatically feeds the machine, as was already the case with sufficient technology known.

As FIG. 6 also shows, the area of application is very extensive and is certainly not exhausted in the examples suggested. It will be here a workpiece according to 14 and 15 with two different contrast media and different Treated patterns. This makes it possible, for example, to do something geometrically similar Large and small parts such as 34 and 35 through pattern comparison and correlation analysis to recognize, as well as foreign parts 35 of the same materials with great certainty and color, however, to separate parts of different shapes.

The method described and the device for optimizing image processing Systems is therefore suitable for enabling simpler image processing, as well as the The limits of the state of the art increase significantly, even beyond difficult problems expand. Only a small amount of equipment is required to apply the Contrast agent can be done efficiently at previous work stages.

At the same time, with a suitable form of the contrast agent, e.g. Flourescin in the case of UV lighting, the process can also be better monitored visually by humans will.

List of reference symbols 1 workpiece 2 edge 2 'edge 3 stimulating Medium 4 transducer, sending side 5 medium sender 6 dispensed medium 7 transducer, receiving side 8 Receiver 9 Contrast agent 1o Edge contrast 11 Contour contrast 12 Grid contrast 13 Dot network contrast 14 Contour contrast medium A 15 Grid contrast medium B 16 Binary contrast 17 Y light guide 18 edge with contrast agent 19 sleeve (workpiece) 20 transmitter for UV 21 receiver for remission 22 light table 23 piece of leather 24 sole punch 25 Hole in the leather 26 Video camera / sensor 27 Converter optics 28 Sewing sensor like 17 29 Sleeves / Cutting 30 gripping device 31 handling robot 32 video camera / sensor 33 Parts storage 34 small part 35 foreign part 36 large part 37 receiving system 38 Transmitter system.

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Claims (10)

Method and device for optimizing image processing systems in textile and operator processing claims 1. A method for optimizing image processing Systems in textile and leather processing, characterized in that a workpiece A contrast agent is used to treat the inside or outside of the workpiece is stimulated by a blasted medium or some other field effect to emit a metrologically detectable signal of a certain property, as well as that Signal is routed to a receiver or receiver matrix that is only used for the output Response are sensitive and capable of automatically converting the signal a picture or certain properties of the object must be presented or evaluated. 2. The method according to claim 1, characterized in that the workpiece with the contrast agent, as well as a possible accelerator, preferably on one Edge io to distinguish between edges, as well as on a contour ii to generate a Contour image, or with a grid 12 or a dot network 13 for generating a reference system, or with a network 15, as well as contour 14 with different contrast media to generate oriented contour images, or flat according to 16 to achieve of a binary image has been treated. 3. The method according to claim 1 or 2, characterized in that the Contrast agent from a stimulable Flourescin, or magnetic, di electrical or radiological preparation with Netzer, which normally is invisible and only reacts to the stimulating medium that is beneficial in one previous operation can be sprayed, pressed on or printed, as well as is soluble in solvents. 4. Apparatus according to claim 1 and 2, characterized in that a Transmitter 5 emits a medium 3 via a transducer 4, since the contrast agent 9 stimulates, so that a measurable specific contrast after 10-16 between edge 2 and workpiece 1 is created by medium 6 and converter 7 on the receiver side at the receiver 8 produces a measurable signal. 5. The method and device according to claim 1 to 4, characterized in that that a Y-light guide 20-21 can be used for edge scanning to a to control the automatic sewing process. 6. The method and device according to one of the preceding claims characterized in that a piece of leather 23 on the edge and holes 25 such characterized by a contour image 11 with a pattern recognition system 26 and 27 a subsequent work process can be controlled. 7. The method and device according to one of the preceding claims characterized in that a workpiece 29 as a binary image 16 from a recognition system according to the method according to the invention is identified to be a handling robot 31 and a sewing machine 28 to control. 8. The method and device according to one of the preceding claims characterized in that according to the method according to the invention according to 14 and 16 Parts of different sizes, colors and materials with correlation methods by 37 and 38 can be distinguished from one another and separated. 9. The method and device according to one of the preceding claims 1 to 8, characterized in that the individual elements from 1o to 16 either can be used advantageously individually or in combination. 10. The method and device according to one of the preceding claims characterized in that the devices according to Figure 3 to 6 individually or in Combination can be used advantageously in a verkette th flexible Line.