GB2587511A

GB2587511A - Optical inspection and sorting machine, and corresponding method thereof

Info

Publication number: GB2587511A
Application number: GB2016718.5A
Authority: GB
Inventors: Mark Murray Deefholts Benedict
Original assignee: Buehler UK Ltd
Current assignee: Buehler UK Ltd
Priority date: 2018-04-20
Filing date: 2019-04-12
Publication date: 2021-03-31
Anticipated expiration: 2039-04-12
Also published as: WO2019201786A1; GB2587511B; GB202016718D0

Abstract

Proposed is an optical sorting machine (1) for sorting of granular objects (1.13) affected by a mold producing aflatoxin. Thus, the granular objects (1.31) can be at least partially contaminated (for example, hotspot contamination) by the highly toxic aflatoxin. The optical sorting machine (1) comprises feeders (1.11) for passing the objects (P) through a sorting zone (1.4). The sorting zone (1.4) comprises illumination means (1.6; 3, 3'), one or more optical detectors (1.7; 7) sensing reflected light or emitted fluorescent light (FE), and sorting means (1.5) for separating desired objects (1.131) showing no aflatoxin contamination to an accept stream (1.42) and undesired objects (1.132) showing an aflatoxin contamination to a reject stream (1.43).

Claims

Claims

1 . An optical sorting machine (1 ) for sorting of granular objects (1 .13; P) that comprises a hopper (1 .1 ) and/or feeders (1 .1 1 ) for passing the objects (1 .13; P) to a sorting zone (1 .4), the sorting zone (1 .4) comprising illumination means (1 .6; 3, 3'), one or more optical sensors (1 .7; 7) sensing reflected (1 .62) or emitted (1 .63) light (FE) from the objects (1 .13; P), and sorting means (1 .5) for separating desired objects (1 .131 )â o an accept stream (1 .42) and undesired objects (1 .132) to a reject stream (1 .43), characterized in that the optical sorting machine ( 1 ) comprises optical splitter means (1 .81 ) for measuring luminous intensifies of the reflected (1 .62) and/or emitted light (1 .63), or a photometric equivalent thereof sensed by the optical sensors (1 .7; 7), in at leasâ a firsâ and a second wavelength range (1 .631 , 1 .632. 1 .63x), in that the optical sorting machine (1 ) comprises trigger means (1 .2) for triggering trigger identifications (1 .221 ) of undesired objects (1 .132) based on their luminous intensities measured in the aâ leasâ firsâ and the second wavelength range (1 .631 , 1 .632) of the emitted light (1 .63), by means of a plurality of defined sets of aâ leasâ 2-dimensional intensity trigger vectors (1 .21 ), wherein each defined set of intensity trigger vectors (1 .21 ) defines an intensity color space (31.34) of trigger identifications (1 .22) of objects by luminous intensities in the aâ leasâ firsâ and second wavelength ranges (1 .631 /1 .632), wherein at leasâ one of the intensity color spaces (32, 33) comprises trigger identifications (1 .22) of objects with a higher probability of correctly identifying undesired objects (1 .132) than at leasâ one other of the intensity color spaces (31 ,34), in that the optical sorting machine (1 ) comprises a frequency counter (1 .31 ) for measuring a frequency or number of undesired objects (1 .132) identified in the aâ leasâ one of the intensity color spaces (32, 33) with the higher probability of triggering undesired objects (1 .132), and comprises measuring means (1 .32) for measuring an overall frequency or number of objects passing the sorting zone (1 .4), and in that the optical sorting machine (1 ) comprises a steering device (1 .9) for controlling the operation of the sorting means (1 .5) by means of two switched modes switching between sorting and monitoring the operation of the sorting machine (1 ), wherein if a predefined threshold value of the frequency or number of undesired objects (1 .132) identified in the at least one of the intensity color spaces (32, 33) with the higher probability as a portion of the measured overall frequency or number of objects passing the sorting zone (1.4) is exceeded, then the sorting means (1 .5) are switched on â o sorting mode (1.931 ), while otherwise the sorting means (1.5) are switched off to only monitoring mode ( 1.932) of the optical sorting machine ( 1 ) .
2. The optical sorting machine (1 ) accordingâ o claim 1 , characterized in that the identified undesired objects (1.132) are objects contaminated by aflafoxin, wherein the objects (1.132) are affected by a mold producing aflatoxin.
3. The optical sorting machine (1 ) accordingâ o one of claims 1 or 2, characterized in that the optical sorting machine (1 ) comprises an interface module (1 .91 ) connecting the optical sorting machine (1 ) to the world-wide backbone network (1 .92; Internet) for automated access to location-specific data (1 .9212, 1 .922.1 .922x) related to the overall risk level or overall probability for aflatoxin contamination in the specific geographic area (1.94) in which the optical sorting machine (1 ) is located and/or that which the granular objects (1 .13) to be sorted come from and/or that in which at least one other sorting machine (1 ) is located, whereby either intensity color spaces (31.34) for triggering the identification of objects are modified based on the accessed data (1.921 1 , 1.921.1.92x1 ) or the predefined threshold value is modified based on the accessed data.
4. The optical sorting machine (1 ) accordingâ o one of claims 1 to 3, characterized in that the optical sorting machine (1 ) comprises an interface module (1 .91 ) connecting the optical sorting machine to the world-wide backbone network (1 .92; Internet), where when the frequency of occurrence of objects (1 .132) in the at least one intensity color space (32, 33) is higher than a second threshold, the sorting machine will create an alert over the Internet connection (1.92)â o warn an operator of the sorting machine (1 ) that the product contamination may be too high, resulting in a higher probability that the accept product (1.42) is also contaminated .
5. The optical sorting machine (1 ) accordingâ o one of claims 1 to 4, characterized in that the optical sorting machine (1 ) comprises an interface module (1 .91 ) connecting the optical sorting machine (1 ) to the world-wide backbone network (Internet), wherein the sorting machine (1 ) reports details of its mode of operation, either sorting or monitoring, to the cloud-based database, and this information being used for a technical billing procedure of a customer, providing a report to the customer, or both.
6. The optical sorting machine (1 ) according to one of claims 1â o 5, characterized in that the optical sorting machine (1 ) comprises an interface module (1 .91 ) connecting the optical sorting machine (1 )â o the world-wide backbone network (interneâ ) (1.92), wherein data on the sorting modes uploadedâ o a cloud-based database (1.921 ) by a plurality of sorting machines (1 ) is usedâ o assess the generated risk of contamination in the local area (1 .94) and/or is used for creating alertsâ o other users in the geographical area (1.94).
7. The optical sorting machine (1 ) according to one of claims 1â o 6, characterized in that the firsâ wavelength range (1.631 ) is between 450 - 495 nm in the blue light range and the second wavelength range (1 .632) is between 495 - 570 nm in the green light range.
8. The optical sorting machine (1 ) according to one of claims 1â o 7, characterized in that the one or more optical detectors (1 .7) aâ leasâ comprise cameras (1 .71 ) for splitting the received reflected or emitted light into two wavelength ranges using a prism with a dichroic filter element.
9. The optical sorting machine (1 ) according to one of claims 1â o 8, characterized in that the illumination means (1 .6) cause the objects (1.132) to fluoresce and comprise aâ leasâ one incident light emitter emitting one or more incident light beams, and further characterized in that the optical detectors (1 .7) are configuredâ o detect fluorescence emitted from the objects (1 .132).
10. The optical sorting machine (1 ) according to claim 9, characterized in that the incident light beam(s) comprise ultraviolet light (UV).
11. The optical sorting machine (1 ) according to one of claims 9 or 10, characterized in that the sorting machine (1 ) sensing the fluorescence emitted by the optical detectors (1 .7) comprises optical filters (1 .81 ) for isolating the incident light beam(s) and the emitted fluorescence.
12. The optical sorting machine (1 ) according to claim 1 1 , characterized in that the optical filters (1 .81 ) for isolating the incident light beam(s) and the emitted fluorescence comprise filter fluoromefers using filtersâ o isolate the incident light and fluorescence or specfrofluoromefers using diffraction grating monochromatorsâ o isolate the incident light and fluorescence.
13. The optical sorting machine (1 ) according to one of claims 1 to 12, characterized in that the one or more optical defectors (1 .7) aâ leasâ comprise cameras (1 .71 ) .
14. The optical sorting machine (1 ) according to one of claims 1 to 13, characterized in that the sorting means (1 .5) comprise one or more ejectors (1 .5) ejecting undesired objects (1 .132) from the objects (1 .13) to be sorted, thereby providing the accept stream (1 .42) and the reject stream (1 .43) .
15. The optical sorting machine (1 ) according to claim 14, characterized in that the one or more ejectors (1 .5) aâ leasâ comprise pneumatic ejectors (1 .51 ).
16. A method for an optical sorting machine (1 ) for sorting of granular objects (1 .13; P), which comprises passing the objects (1 .13; P) by a hopper (1 .1 ) and/or feeders (1 .1 1 ) and/or chutes (1 .12; 1 .121 , 1 .122.1 12x)â o a sorting zone (1 .4), the sorting zone (1 .4) comprising illumination means (1 .6; 3, 3'), one or more optical sensors (1 .7; 7) sensing reflected (1 .62) or emitted (1 .63) light (FE) from the objects (1 .13; P), and sorting means (1 .5) for separating desired objects (1 .131 )â o an accept stream (1 .42) and undesired objects (1 .132) to a reject stream (1 .43), characterized in that luminous intensities of the reflected (1 .62) and/or emitted light (1 .63) or a photometric equivalent thereof, sensed by the optical sensors (1 .7; 7) are measured by optical splitter means (1 .81 ), in at leasâ a firsâ and a second wavelength range (1 .631 , 1 .632. 1 .63x), in that trigger identifications (1 .221 ) of undesired objects (1 .132) are triggered by trigger means (1 .2) based on their luminous intensities measured in the at least first and the second wavelength range (1 .631 , 1 .632) of the emitted light (1 .63), by means of a plurality of defined sets of at least 2-dimensional intensity trigger vectors (1 -21 ), wherein each defined set of intensity trigger vectors (1 .21 ) defines an intensity color space (31.34) of trigger identifications (1 .22) of objects by luminous intensities in the at least first and second wavelength ranges (1 .631 /1 .632), wherein at least one of the intensity color spaces (32, 33) comprises trigger identifications (1 .22) of objects with a higher probability of correctly identifying undesired objects (1 .132) than at least one other of the intensity color spaces (31 ,34), in that a frequency or number of undesired objects (1 .132) is measured by a frequency counter (1 .31 ), which undesired objects (1 .132) are identified in the at least one of the intensity color spaces (32, 33) with the higher probability of triggering an undesired objects (1 .132), and an overall frequency or number of objects passing the sorting zone (1 .4) is measured by measuring means (1 .32), and in that the sorting means (1 .5) are operated and steered by a steering device (1 .9) comprising two switched modes switching between sorting and monitoring the operation of the sorting machine (1 ), wherein if a predefined threshold value of the frequency or number of undesired objects (1 .132) identified in the at least one of the intensity color spaces (32, 33) with the higher probability as a portion of the measured overall frequency or number of objects passing the sorting zone (1 .4) is exceeded, then the sorting means (1 .5) are switched on to sorting mode (1 .931 ), while otherwise the sorting means (1 .5) are switched off to only monitoring mode (1 .932) of the optical sorting machine (1 ).