Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
  • B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
  • B07C5/34—Sorting according to other particular properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
  • B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
  • B07C5/36—Sorting apparatus characterised by the means used for distribution
  • B07C5/361—Processing or control devices therefor, e.g. escort memory

Definitions

• the invention relates to a method for identifying and sorting belt-conveyed objects, in particular for sorting waste, in which the material properties of the objects are detected spectroscopically using an NIR measuring device and the sorting as a function of the spectroscopy
• the invention also relates to a device for carrying out this method.
• Another method for identifying and sorting belt-conveyed objects is known from DE 43 05 006 A1.
• the material properties of the objects to be sorted are recorded by means of a polarization interferometer, and a Fast Fourier analysis is used to evaluate the data supplied by this interferometer.
• Such a device for determining the material properties of the objects to be identified and sorted also has a detection area which is essentially limited to a single measuring point and is therefore subject to the same disadvantages as previously explained; that is, a relatively complex presorting and separation is required before the objects are fed to the point-like measuring location.
• such a measuring device is critical with regard to the distance to the measurement object.
• the invention has for its object to provide a method of the type mentioned in the preamble of claim 1, by means of which objects of any shape can be reliably identified and sorted, and which can in particular be integrated into existing waste sorting systems.
• a device for performing this method is to be provided.
• the method according to the invention eliminates the disadvantage of the prior art in terms of complex pre-sorting and separation by providing a relatively large detection area that can be approached differently by scanning the object's scanning movement of the measuring point of the NIR measuring device above the object-carrying conveyor belt.
• a scanning movement is preferably achieved by a scanning device in the form of a mirror arrangement for directing the measuring point of the NIR device onto the objects.
• the NIR measuring device can identify different object materials simultaneously. In principle, this requires longer exposure times or sampling times as with the NIR State of the art scanning. However, this is made up for by the fact that measurements do not have to be carried out at all locations on the conveying channel, but only where the image processing according to the invention, which precedes the NIR measurement, has located an object.
• the NIR spectral analysis is preceded by an image analysis, preferably a color image analysis, for localization, including optionally determining the shape and size of the objects to be identified.
• image analysis preferably a color image analysis, for localization, including optionally determining the shape and size of the objects to be identified.
• the information obtained by means of image analysis is used to control the movement of the scanning device connected upstream of the NIR measuring device; This means that only a specific scan of the objects to be identified follows, with the exception of points on the conveyor belt that are not occupied by objects. This makes the scanning process rational.
• the image analysis provides information about shape, size, color and, for example, texture, which ensures better selection.
• a new (color) image analysis based on another camera downstream of the separation point can be used to recognize the objects which have remained on the conveyor belt with regard to their possibly changed position, and without renewed NIR spectroscopy if the data this camera with the already acquired NIR data in a matching manner.
• the NIR values already obtained and saved can be used in every further separation step.
• the method according to the invention is based on the following principle:
• an object for example, garbage 1
• the position, shape, contour, size, color and texture can be recognized and the relevant parameters saved.
• the material properties of the objects are then determined using NIR spectroscopy.
• infrared radiation in NIR spectroscopy concentrates on only one measuring point.
• a mirror device is proposed which brings the infrared rays to the desired scanning point.
• the reverse procedure is preferred, i.e. illumination of the entire detection area and control of the measuring optics in such a way that only reflected infrared rays from desired measuring points on the respective object are detected.
• This mirror system is controlled with the help of previously obtained information from the image recognition.
• the data obtained from the (color) image recognition and infrared radiation are combined and provide signals for controlling a device for the targeted discharge of objects, for example in the form of a fading nozzle arrangement.
• the method according to the invention Identification and separation of several object fractions in a single system guaranteed. This system can easily be trained to recognize new objects by placing enough of these new objects on the conveyor belt in a learning phase.
• the method and the device according to the invention are particularly advantageously suitable for sorting household waste.
• the method according to the invention allows all objects to be visually localized on 1 m 2 of a conveyor belt in a period of less than 50 ms.
• the NIR measurement of an individual object typically requires 3 ms and the subsequent evaluation to identify the object typically takes 1 to 2 milliseconds.
• the device shown in the figure consists of three device complexes: an analysis complex 1 with a first separation complex, a second separation complex 2 and one third separation complex 3.
• Each of these three complexes 1, 2 and 3 comprises an endless belt conveyor 4, 5 and 6 with conveyor belts 7, 8 and 9, which are all arranged in the same horizontal plane and adjoin one another with the interposition of blow-off nozzle strips.
• a blow nozzle bar 10 is arranged between the downstream end of the belt conveyor 4 and the upstream end of the belt conveyor 5, while a blow nozzle bar 11 is arranged between the downstream end of the belt conveyor 5 and the upstream end of the belt conveyor 6.
• blow-off nozzle strips extends over the full width of the respective conveyor belt 7, 8 and 9, immediately adjoins their corresponding deflecting ends and is relatively narrow in order to ensure that conveyed on the conveyor track formed by the conveyor belts 7, 8 and 9 Goods can easily run over the blow-off nozzle strips 10, 11.
• a plurality of blowing nozzle openings extend across the blow nozzle bars 10, 11.
• the conveyor line defined by the belt conveyors or their conveyor belts, together with the units assigned to them, which are explained in more detail below, is used, for example, for sorting waste.
• the analysis complex 1 above the belt conveyor 4 of this complex comprises a color camera 12, an NIR spectrometer 13 with an NIR sensor 14 and an optical scanning head 15.
• a computer 16 is used, which is preferably arranged at a distance from the units 12 to 14 and can also be integrated into a computer network, as listed below.
• the outputs of the color camera 12 and the NIR spectrometer 13 are connected to corresponding inputs of the computer 16.
• the NIR sensor 14, which can also form an integral part of the NIR spectrometer 13, is connected to the NIR spectrometer for the transmission of measured values.
• the optical scanning head 15 consists of a (mirror) lens arrangement known per se, which can be displaced, for example by a motor, in such a way that a detection area 18 is scanned point by point on the conveyor belt 7, the scanned measuring point being input into the NIR sensor.
• a measuring point is designated by the reference number 19.
• the optical scanning head 15 is designed such that the detection area 18 has a rectangular shape, extends over the full width of the conveyor belt 7 and has a given length in the conveying direction. Typically, the detection area 18 has an area of approximately 1 m 2 when a standard conveyor belt with a width of 100 cm is used.
• the detection area 17 of the color camera 12 corresponds in terms of its shape and size to that of the detection area 18; that is, the detection area 17 also has a rectangular shape and extends over the full width of the conveyor belt 7 Analysis complex 1 by two detection areas, a detection area 17, in which the shape and / or surface condition and position of objects on the conveyor belt 7 are detected, and a detection area 18 downstream of this detection area for detecting the material properties of precisely these objects.
• the output data of the color camera 12 and the output data of the NIR spectrometer 13 are evaluated in the computer 16.
• objects on the belt conveyor can thus be classified and recorded in terms of shape, size, color, texture and the like.
• NIR spectroscopy enables a high spectral resolution of, for example, up to 256 (512) frequency channels with a width of approximately 2 to 4 nm at a single spatial measurement location. From this total information, material properties at the measuring location or at the object can be concluded. If the spatial resolution of the camera 12 is combined in the visible range with rapid control of the NIR measurement location over the respective detection range 17 to 18 of approximately 1 m 2 , an NIR measurement with spatial resolution can be simulated. This provides a very secure object localization and identification, without the need for complex object separation beforehand. This means that pre-separation is only necessary to the extent that the objects can be distinguished from one another in plan view.
• a further color camera 22 is arranged above the conveyor belt 8, which is connected to the computer 16 similarly to the color camera 12 of the analysis complex 1 and for detecting an area 23 on the conveyor belt 8 serves.
• the first separation complex 2 (as well as further downstream separation complexes, such as, for example, the separation complex 3) can be assigned its own computer which is networked with the computer 16, as mentioned above.
• This detection area 23 has the same shape size and relative position to the conveyor belt 8 as the detection areas 17 and 18 to the conveyor belt 7 of the first analysis complex.
• the detection data from the color camera 22 processed in the computer 16 permit detection of the remaining objects and, if necessary, their change in position.
• NIR values can be used and used for a further separation step that takes place downstream of the first separation complex, namely through the blow nozzle bar 11 between the belt conveyor 5 and the belt conveyor 6. Objects are discharged in a targeted manner in the direction of an arrow 24 to a collecting device 25 and from there via a chute or a cross conveyor 25a by means of the blow nozzle bar 11.
• the second separation complex 3 is constructed identically to the first separation complex 2 and accordingly has a further color camera 26 which captures an area 27 on the conveyor belt 9, the size and shape of which corresponds to that of the preceding detection areas.
• the operation of the second separation complex 3 corresponds to that of the first separation complex explained above, with the difference that the image reference data are used as reference data, which were acquired by the color camera 22 of the first separation complex, instead of the data provided by the color camera 12 of the analysis complex were.
• the device according to the invention explained above is not limited to the system shown with only three separation complexes. Rather, depending on the particular requirements, more separation complexes or only a single separation complex can be used.
• the cameras 12, 22 and 26 are color cameras; rather, black and white cameras can also be used if necessary.

Landscapes

• Sorting Of Articles (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Discharge Of Articles From Conveyors (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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Cited By (1)

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• 1997
  • 1997-11-22 DE DE19751862A patent/DE19751862C2/de not_active Revoked
• 1998
  • 1998-11-13 ES ES98961191T patent/ES2166193T3/es not_active Expired - Lifetime
  • 1998-11-13 AT AT98961191T patent/ATE206961T1/de active
  • 1998-11-13 EP EP98961191A patent/EP1030740B1/fr not_active Expired - Lifetime
  • 1998-11-13 AU AU16699/99A patent/AU1669999A/en not_active Abandoned
  • 1998-11-13 WO PCT/EP1998/007267 patent/WO1999026734A1/fr active IP Right Grant
  • 1998-11-13 JP JP2000521927A patent/JP2001523574A/ja active Pending
  • 1998-11-13 CA CA002310838A patent/CA2310838A1/fr not_active Abandoned

Non-Patent Citations (1)

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