Method for parameterizing a machine-vision lighting device

{
  "publication_number": "US11395382B2",
  "country": "US",
  "kind": "B2",
  "title": "Method for parameterizing a machine-vision lighting device",
  "abstract": "A method for parameterizing a machine-vision device. The method incudes the e following successive steps: a) selecting, depending on the zone of interest, a slaved lighting configuration, and recording the slaved lighting configuration in the control interface and/or applying the slaved lighting configuration; b) independently of step a), selecting an origin lighting configuration, and applying the origin lighting configuration; c) establishing an informational relationship between said origin and slaved lighting configurations and recording said relationship in the control interface so that the electronic unit commands the zone of interest to be lit in the slaved lighting configuration in response to an origin lighting configuration.",
  "claims": [
    "1. Method for parameterizing a machine-vision device, said machine-vision device comprising: a camera system comprising a camera and first and second origin light sources configured to, in an origin lighting configuration, emit first and second origin light signals, respectively; a lighting device comprising: a control interface comprising: first and second light sensors arranged to capture said first and second origin light signals, respectively, and to emit first and second sensor signals, respectively, in response to the capture of said first and second origin light signals, respectively; an electronic unit for processing said first and second sensor signals, said electronic processing unit being configured to send, as a result of said processing, a plurality of control signals to respective outputs of the electronic processing unit; a plurality of slaved light sources, each connected to one respective output of the electronic processing unit so as to be controlled with the control signal delivered to said output in order to light a zone of interest; said method comprising the following successive steps: a) selecting, depending on the zone of interest, a lighting configuration for the slaved light sources, called the “slaved lighting configuration”, and recording the slaved lighting configuration in the control interface and/or applying the slaved lighting configuration; b) independently of step a), selecting a lighting configuration for the origin light sources, or “origin lighting configuration”, and applying the origin lighting configuration; c) establishing an informational relationship between said origin and slaved lighting configurations and recording said informational relationship in the control interface so that the electronic unit commands the zone of interest to be lit in the slaved lighting configuration in response to reception, by said sensors, of origin light signals in the origin lighting configuration.",
    "2. Method according to claim 1, wherein, in step c), said informational relationship between the origin and slaved lighting configurations is recorded via action on a programming member of the control interface.",
    "3. Method according to claim 1, wherein, in step a), a plurality of slaved lighting configurations is tested, so as to find and select a slaved lighting configuration that is optimal with respect to the effectiveness of a recognition, by the machine-vision device, of objects placed in the zone of interest.",
    "4. Method according to claim 1, wherein, in step b), the selection of the origin lighting configuration is independent of the slaved lighting configuration in step a).",
    "5. Method according to claim 1, wherein, in an assembled position in which the camera is fastened to the control interface, the origin light sources face one or more respective light sensors and are at less than 3 cm from said respective light sensors.",
    "6. Method according to claim 1, wherein each light sensor is placed so that the light that it receives originates, as regards more than 50% of its intensity, from one or more origin light sources that face it.",
    "7. Method according to claim 1, wherein the slaved light sources are kept active, in the slaved lighting configuration selected in step a), during the application of the origin lighting configuration in step b) and/or until said informational relationship has been established in step c).",
    "8. Method according to claim 1, wherein: in step a), the slaved lighting configuration is selected from a database of slaved lighting configurations stored in the control interface; and/or in step b), the origin lighting configuration is selected from a database of origin lighting configurations stored in the camera.",
    "9. Method according to claim 1, wherein, the origin light sources are adjustable by an operator independently and, in step a), to select the slaved lighting configuration, an operator adjusts at least one origin light source independently of the other origin light sources.",
    "10. Method according to claim 1, wherein said origin light sources are integrated into the camera and/or the slaved light sources are integrated into the control interface.",
    "11. Method according to claim 1, wherein, in the slaved lighting configuration, at least two slaved light sources are configured to emit different light spectra.",
    "12. Method according to claim 1, wherein the camera is fastened, preferably magnetically, to the control interface in a preset position.",
    "13. Method according to claim 1, wherein the cycle of steps a) to c) is repeated in order to establish a plurality of said informational relationships suitable for recognition, by the machine-vision device, of a plurality of different objects.",
    "14. Method according to claim 1, wherein the one or more slaved light sources are configured to emit flashes of a duration shorter than 10 ms and/or a light spectrum of a width narrower than 100 nm, and/or wherein at least some of the slaved light sources are configured to emit in a domain of non-visible frequencies.",
    "15. Method according to claim 1, wherein the control interface is passed through by an aperture and the optical axis of the camera is substantially aligned with the axis of the aperture, the slaved light sources being placed on the side of the control interface opposite to the camera.",
    "16. Device for conveying objects, comprising at least: one track for conveying objects, and one machine-vision device parameterized using a method according to any one of the preceding claims, the slaved light sources being suitable for lighting at least one segment of the track for conveying objects."
  ],
  "description_excerpt": "The present invention relates to a method for parameterizing a machine-vision device.\n\nIn the industrial field, it is known to inspect objects visually in order to identify them or to verify the conformity thereof. This inspection is advantageously carried out automatically by means of a machine-vision device. Such a machine-vision device conventionally comprises light sources that light a zone of interest containing the objects to be inspected, and a camera for taking images of this zone of interest. The images are then processed by an image-analyzing software package, which may or may not be integrated into the camera.\n\nThe quality of the contrast, and therefore the robustness of the inspection, depend on the lighting configuration. The lighting may for example be directional, diffuse and indirect, coaxial, with a grazing incidence with respect to the axis of the camera, or even such as to produce silhouettes. The color of the lighting must be adapted to the objects. For example, it may be necessary to light in red objects conveyed on a blue conveyor belt, the objects thus appearing white on a black background to a monochromic camera.\n\nLastly, conventionally, the light sources do not provide light continuously, but do so intermittently, in the manner of a stroboscope. The light sources thus emit successive flashes of a duration equal to or slightly longer than the exposure time of the camera. This allows the moving items on the conveyor belt to be “frozen” during the acquisition of the images by the camera.",
  "cpc": [
    "H05B 45/10",
    "B25J 9/1697",
    "G01B 11/24",
    "G01N 21/8806",
    "G03B 15/02",
    "G03B 2215/0539",
    "H04N 23/56",
    "H04N 23/66",
    "H04N 23/74",
    "H05B 45/20",
    "H05B 47/105"
  ],
  "ipc": [
    "B25J 9/16",
    "H05B 45/10"
  ],
  "assignees": [
    "TPL Vision UK Ltd"
  ],
  "inventors": [
    "Guillaume Mazeaud",
    "Jack MCKINLEY",
    "Nedko GATEV"
  ],
  "filing_date": "2019-11-01",
  "publication_date": "2022-07-19",
  "grant_date": "2022-07-19",
  "priority_date": "2018-11-05",
  "application_number": "US-201916671434-A",
  "family_id": "66542287",
  "cited_by_count": 0,
  "citations": [
    "US20200134773A1"
  ]
}