WO2020086698A1 - Procédés et systèmes utilisés pour mesurer des bandes de roulement de pneu - Google Patents

Procédés et systèmes utilisés pour mesurer des bandes de roulement de pneu Download PDF

Info

Publication number
WO2020086698A1
WO2020086698A1 PCT/US2019/057623 US2019057623W WO2020086698A1 WO 2020086698 A1 WO2020086698 A1 WO 2020086698A1 US 2019057623 W US2019057623 W US 2019057623W WO 2020086698 A1 WO2020086698 A1 WO 2020086698A1
Authority
WO
WIPO (PCT)
Prior art keywords
tire
camera
tread
radiation
image
Prior art date
Application number
PCT/US2019/057623
Other languages
English (en)
Inventor
Stephen W. BROOKS
David Alan Koester
Aaron Daniel Franklin
Jesko Von Windheim
James Barton Summers III
JR. Carl Ray PREVATTE
Original Assignee
Tyrata, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tyrata, Inc. filed Critical Tyrata, Inc.
Publication of WO2020086698A1 publication Critical patent/WO2020086698A1/fr

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60CVEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00Tyre tread bands; Tread patterns; Anti-skid inserts
    • B60C11/24Wear-indicating arrangements
    • B60C11/246Tread wear monitoring systems
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/22Measuring arrangements characterised by the use of optical techniques for measuring depth
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/24Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G01B11/25Measuring 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
    • G01B11/2518Projection by scanning of the object
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/24Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G01B11/25Measuring 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
    • G01B11/2545Measuring 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 with one projection direction and several detection directions, e.g. stereo
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B21/00Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
    • G01B21/02Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
    • G01B21/04Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness by measuring coordinates of points
    • G01B21/047Accessories, e.g. for positioning, for tool-setting, for measuring probes
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01MTESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M17/00Testing of vehicles
    • G01M17/007Wheeled or endless-tracked vehicles
    • G01M17/02Tyres
    • G01M17/027Tyres using light, e.g. infrared, ultraviolet or holographic techniques

Definitions

  • the present disclosure relates generally to tires, and more particularly, to tire tread monitoring systems and related methods.
  • U.S. Patent No. 9,677,973 (entitled“Method and Apparatus for Environmental Protection of Drive-Over Tire Tread Depth Optical Sensors” to Carroll et al.) discusses use of optical sensors for the acquisition of data associated with tire conditions of vehicle wheels. As further discussed, optical sensors are disposed in, or below, a supporting surface over which the vehicle wheels roll. Embedded or drive-over optical sensors may include components for projecting illuminating energy towards and onto the surfaces of a passing vehicle, as well as receiving components for capturing reflected energy from the passing vehicle.
  • some tire tread depth measurement systems consist of a laser emitter configured to project a laser light onto or across the surface of a tire passing over the optical sensor, and a cooperatively configured imaging sensor for acquiring images of the projected laser light reflected from the passing tire.
  • Other systems/methods are discussed in U.S. Patent No. 9,805,697 (entitled “Method for Tire Tread Depth Modeling and Image Annotation” to Dorrance et al.). Such methods/systems, however, may be costly and/or difficult to scale down to fit small enclosures
  • IR infrared
  • the camera may comprise first and second cameras. Infrared (IR) radiation may be projected on the tread using an IR source.
  • a first image of the tread may be generated using the first camera receiving first reflected IR radiation reflected from the tread, and a second image of the tread may be generated using the second camera receiving second reflected IR illumination from the tread.
  • the profile may thus be measured based on the first and second images. For example, a first point cloud may be generated based on the first image, a second point cloud may be generated based on the second image, and the profile may be measured based on the first and second point clouds.
  • the first and second images may be generated responsive to detecting a location of the tire.
  • the location of the tire may be detected based on output from at least one of a proximity sensor, a pressure sensor, and/or an optical sensor.
  • the first and second images may be generated based on the first and second reflected IR radiation reflected from a first portion of the tread.
  • a third image of the tread may be generated using a third camera receiving third reflected IR radiation reflected from a second portion of the tread
  • a fourth image of the tread may be generated using a fourth camera receiving fourth reflected IR illumination from the second portion of the tread.
  • the first and second cameras and the IR source may be moved to maintain a
  • the first image may be generated by generating a plurality of first images using the first camera at different positions while moving to maintain the measurement distance
  • the second image may be generated by generating a plurality of second images using the second camera at different positions while moving to maintain the measurement distance
  • a plurality of profiles of the tread may be measured at different locations based on the pluralities of first and second images.
  • the plurality of profiles may be measured around a circumference of the tire.
  • the first and second cameras and the IR source may be provided on a sled below a track for the tire, wherein moving the first and second cameras and the IR source comprises translating the sled along the track for the tire while the tire rolls on the track.
  • the track may include a portion that is transparent with respect to the IR radiation, the sled may be translated in front of the tire while the tire rolls on the track, and/or the sled may be translated behind the tire while the tire rolls on the track.
  • the first and second cameras and the IR source may be provided below a track for the tire so that the tire rolls over the first and second cameras and the IR source.
  • the track may include a portion that that is transparent with respect to the IR radiation, and/or the track may include an opening to allow transmission of the IR radiation through the opening to the tire.
  • a shutter may be provided on the track, the shutter may be opened to allow projection of the IR radiation and generation of the first and second images through the opening, and the shutter may be closed after generating the first and second images.
  • a visual indication of a status of the tire may be provided based on measuring the profile of the tread.
  • Infrared (IR) radiation may be projected on the tread using an IR source, generating an image of the tread may be generated using the camera receiving reflected IR radiation reflected from the tread, and the profile may be measured based on the image.
  • IR Infrared
  • a point cloud may be generated based on the image, and the profile may be measured based on the point cloud.
  • the image may be generated responsive to detecting a location of the tire (e.g., based on output from at least one of a proximity sensor, a pressure sensor, and/or an optical sensor).
  • the image may be generated based on the reflected IR radiation reflected from a first portion of the tread, a second image of the tread may be generated using a second camera receiving second reflected IR radiation reflected from a second portion of the tread, and a first portion of the profile corresponding to the first portion of the tread may be measured based on the first image, and a second portion of the profile corresponding to the second portion of the tread may be measured based on the second image.
  • the camera and the IR source may be moved to maintain a measurement distance with respect to the tire as the tire rolls, a plurality of images may be generated using the camera at different positions while moving to maintain the measurement distance, and a plurality of profiles of the tread at different locations may be measured based on the plurality of images.
  • the plurality of profiles may be measured around a circumference of the tire.
  • the camera and the IR source may be provided on a sled below a track for the tire, and moving the camera and the IR source may include translating the sled along the track for the tire while the tire rolls on the track.
  • the track may include a portion that is transparent with respect to the IR radiation, the sled may be translated in front of the tire while the tire rolls on the track, and/or the sled may be translated behind the tire while the tire rolls on the track.
  • the camera and the IR source may be provided below a track for the tire so that the tire rolls over the camera and the IR source.
  • the track may include a portion that that is transparent with respect to the IR radiation.
  • the track may include an opening to allow transmission of the IR radiation through the opening to the tire.
  • a shutter may be provided on the track, the shutter may be opened to allow projection of the IR radiation and generation of the image through the opening, and the shutter may be closed after generating the image.
  • systems may be provided to measure a profile of a tread of a tire.
  • Such systems may include an infrared (IR) radiation source, a camera, and a controller coupled with the camera.
  • the infrared (IR) radiation source may be configured to project IR radiation on the tread.
  • the camera may be configured to generate an image of the tread based on receiving a reflection of the IR radiation reflected from the tread.
  • the controller may be coupled with the camera, wherein the controller is configured to measure the profile of the tread based on the image generated by the camera.
  • the camera is a first camera, the reflection may be a first reflection of the IR radiation reflected from the tread, and a second camera may be coupled with the controller, and the second camera may be configured to generate a second image of the tread based on receiving a second reflection of the IR radiation reflected from the tread, and the controller may be configured to measure the profile of the tread based on the first and second images generated by the first and second cameras.
  • the system may also include a drive-over enclosure, wherein the camera and the IR radiation source are provided in the drive-over enclosure.
  • the controller may be configured to measure the profile of the tread based on the image which is generated by the camera with the tire rolling over the drive-over enclosure.
  • the controller may be configured to measure the profile of the tread based on the image which is generated by the camera with the tire moving toward the drive-over enclosure before the tire contacts the roll over drive-over enclosure.
  • the controller may be configured to measure the profile of the tread based on the image which is generated by the camera with the tire moving away from the drive-over enclosure after the tire moves off of the drive-over enclosure.
  • the camera and the IR radiation source may be located to a side of a track of the tire so that the tire rolls by the camera and the IR radiation source.
  • the IR radiation source may be a first IR radiation source, the camera may be a first camera, and the first IR radiation source and the first camera may be located to a first side of the track followed by the tire.
  • a second infrared (IR) radiation source may be configured to project second IR radiation on the tread.
  • a second camera may be configured to generate a second image of the tread based on receiving a reflection of the second IR radiation reflected from the tread, wherein the second camera is coupled with the controller, and wherein the second camera and the second IR radiation source are located to a second side of the track followed by the tire so that the tire rolls between the first and second cameras.
  • the controller may be configured to measure the profile of the tread based on the first and second images generated by the first and second cameras.
  • a translational sled may be configured to move the camera and the IR radiation source to maintain a measurement distance with respect to the tire as the tire rolls, the camera may be configured to generate a plurality of images from different positions as the tire rolls while moving to maintain the measurement distance, and the controller may be configured to measure a plurality of profiles of the tread at different locations based on the plurality of images.
  • the system may also include a roll over enclosure, wherein the translational sled, the camera, and the IR source are provided in the roll over enclosure so that the translational sled is configured to move the camera and the IR radiation source within the roll over enclosure while the tire rolls over the roll over enclosure.
  • the sled is configured to move the camera in front of the tire as the tire rolls, the sled may be configured to move the camera behind the tire as the tire rolls.
  • the system may also include an enclosure configured to lie on a driving surface, where the IR radiation source and the camera are provided within the enclosure.
  • the enclosure may be configured to orient a line of sight of the camera and/or the IR radiation source at an acute angle relative to the driving surface.
  • the enclosure may have a flat surface configured to lie on the driving surface and an elevated driving surface opposite the flat surface, and the line of sight of the camera and/or the IR radiation source may extend through an optical opening through the driving surface.
  • the elevated driving surface may be curved and/or rounded.
  • the system may also include a pneumatic air source in the enclosure, wherein the pneumatic air source is configured to clear an optical path for the IR radiation source and/or the camera.
  • the system may include an optically transparent protective cover provided within the enclosure in the line of sight, and the pneumatic air source may comprise an air knife configured to clean a surface of the optically transparent protective cover.
  • the surface of the optically transparent cover may be provided at an angle that is non-parallel with respect to the flat surface of the enclosure.
  • Figure 1 schematically illustrates a systems using IR stereoscopic techniques according to some embodiments of inventive concepts
  • Figure 2 is a side view illustrating tread measurement systems according to some embodiments of inventive concepts
  • Figure 3 is a front view illustrating tread measurement systems of Figure 2 according to some embodiments of inventive concepts
  • Figure 4 is a top view illustrating tread measurement systems according to some embodiments of inventive concepts
  • Figure 5 is a top view illustrating tread measurement systems according to some embodiments of inventive concepts
  • Figure 6 is a side view of a side view illustrating tread measurement systems according to some embodiments of inventive concepts
  • Figure 7 is a front view illustrating tread measurement systems including optical systems according to some embodiments of inventive concepts
  • Figure 8 is a block diagram illustrating tread measurement systems according to some embodiments of inventive concepts; and Figures 9 and 10 are side views illustrating tread measurement systems according to some embodiments of inventive concepts.
  • Tire tread thickness measurements may be performed using laser profiling, involving the scanning of a single wavelength, unidirectional beam and using the reflection of the beam from the tire surface to ascertain the tire profile.
  • laser-based systems may be highly accurate but may also be costly and/or difficult to scale down to fit small enclosures.
  • Another imaging- based technique to obtain the depth profile of a surface is to use infrared (IR) camera units (IR source + detectors). IR technology has become affordable and accessible but may require proper integration to enable a specific application.
  • IR infrared
  • inventions of inventive concepts illustrated in Figure 1 may provide a system that uses IR stereoscopic techniques to triangulate the distance of specific points on a tire surface from the two cameras mounted in an imaging unit. This technique may be uniquely applied herein to the measurement and profiling of tire tread surfaces.
  • the system may include an IR unit 101 (also referred to as an IR optical unit, an optical unit, an IR optical system, an optical system, etc.) enclosed in a low-profile structure 103 where the top surface may provide an optical opening 121 for the IR light, thus enabling a clear view between the IR unit 101 and the tire surface 111.
  • Two IR detectors l07a and l07b in the IR unit 101 collect data from the surface 111 of the tire 115 and the data is compared to determine the relative height/depth of each measurement.
  • An IR source 109 i.e., a high intensity IR lamp or LED
  • Two IR detectors l07a and l07b, placed a fixed distance apart may provide stereoscopic images as shown in Figure 1.
  • Embodiments of this disclosure in Figure 1 may provide a system incorporating an IR source 109 and two IR detectors l07a and l07b (e.g., IR sensor cameras) for in-motion tire tread thickness measurement.
  • Inventive aspects may include the integration of the IR unit 101 into a drive-over enclosure (e.g., low-profile structure 103 of Figure 1), protection of the unit with a shutter and appropriate antireflective glass, handling and processing of the collected tire profile image, and other modes of integration of the IR unit.
  • the system may include an IR unit (source + detectors) enclosed in a low-profile
  • the system may employ multiple IR units, used cooperatively to enable measurement of all tires attached to the vehicle under inspection.
  • the system may have markings on the external surfaces to guide an operator during its use.
  • the system may be used with equipment providing visual indication of status such as readiness, fault or measurement completion.
  • the system may contain a single IR camera system (2 cameras + illuminator) to read each tire surface or more than one system to provide wider coverage.
  • Figure 2 is a side view illustrating a sensor system according to some embodiments in a roll-over mat providing a low-profile roll over structure 103.
  • Figure 3 is a front view illustrating the system of Figure 2 with a tire 115 rolling over an enclosure including the optical unit 101 (e.g., IR camera system with and IR source and IR detectors).
  • the optical unit 101 e.g., IR camera system with and IR source and IR detectors.
  • a cone of light 141 (extending from optical unit 101) is shown illuminating the tire area of interest.
  • the system includes an IR unit 101 mounted inside a ramp or a sub-surface enclosure (providing a low profile structure 103) at an appropriate angle to capture an
  • the IR unit 101 has a certain focal length and is designed to capture the measurement image when the tire 115 is in focus.
  • the IR unit 101 may optionally be covered by a transparent antireflective material (or material with an antireflective coating providing optical opening 121) allowing IR light to pass through while protecting the IR unit 101 from particles.
  • the system may operate while the vehicle is in motion.
  • the speed of the IR unit 101 may be capable of capturing the tire 115 in motion without sacrificing resolution.
  • the system may include additional proximity sensors, pressure sensors, optical sensors, and/or motion sensors to determine the location of the oncoming tire and provide/ensure proper timing of image capture.
  • the system may include a protective shutter over the IR optical unit 101, triggered to open responsive to detection of an incoming tire 115 and then closing to protect the IR unit 101 prior to the tire 115 passing over the IR optical unit 101.
  • the system may include multiple IR optical units lOla and lOlb (one unit being one source and two IR detectors) to capture extremely wide tires (e.g. truck tires, commercial vehicle tires, industrial and mining tires) or dual wheels (as shown by IR optical units lOla and lOlb in Figure 7).
  • Each optical unit lOla and lOlb may be used to measure respective different portions 11 la and 11 lb of the tire tread. These images can be subsequently stitched together to create a single image.
  • the system may include multiple ramps (or tracks) to simultaneously measure both left and right tires.
  • the system may include indicators that provide feedback to drivers on the status of the tires based on measured tire tread profile.
  • the indictors may be similar to stoplights that provide one of a green (safe), yellow (marginal), or red (unsafe) light to the driver based on the measured tire tread profile.
  • the system may provide quantitative data on the status of the remaining tire tread on a display.
  • the system may include an ancillary interface to review data, print output, and/or collect and/or review older data files.
  • This station may reside in the service lane office or other places in a tire or other type of shop.
  • Output from the system may be sent directly to a cloud-based database for future
  • the IR images may be combined with standard red-green-blue RGB color images from a complimentary camera to produce a realistic display of the measured tire to the user.
  • the IR unit sensor may be mounted in a handheld system that can be used to image the surface of the tire to capture tire tread thickness profile.
  • the IR unit may be mounted in a system inside the tire well to continuously capture tread wear data.
  • the IR unit may be mounted to an automated guided vehicle system, which may independently identify and measure tires on parked or moving vehicles.
  • the cameras may be nominally mounted directly under the path of the tire to provide a clear and ostensibly normal view of the tire.
  • Some embodiments described herein may also use IR camera systems with the IR cameras configured differently to provide images of the tire from two distinctly different view angles.
  • Other embodiments may provide for a camera system that is mounted inside a sliding track that follows the tire while simultaneously capturing imaging information that can be converted into a full circumferential map of tire tread.
  • these embodiments may use IR stereoscopic techniques to triangulate the distance of specific points on a tire surface from the two cameras mounted in an imaging unit. This technique may be uniquely applied herein to the measurement and profiling of tire tread surfaces.
  • Two IR cameras/detectors, placed a fixed distance apart may provide stereoscopic images as shown in Figure 1.
  • the detectors (cameras) and IR source may be provided in an IR camera unit (IRCU), with the IR source projecting IR radiation and the cameras detecting the IR signal reflected from the tire surface.
  • the camera unit may be positioned off the axis of tire motion. This may be in contrast to the orientation of Figure 1 where the camera unit is shown in the axis of motion.
  • the system may include four separate IR camera units lOla’, lOlb’, lOlc’, and lOld’, IRCUs (configuration 1, Fig. 4), wherein each IRCU includes an IR source and one or two IR detectors/cameras. Each IRCU is enclosed in a housing to protect the camera and any associated optics and electronics from environmental damage or damage from inadvertent vehicle roll-over.
  • the center two IRCUs lOlbc’ may occupy a same housing. In this configuration, the cameras may be mounted further from the tire path.
  • the data cloud (3D image data) from each IRCU is combined with data from the other IRCU incident on the same tire to provide a more comprehensive image of the tire surface. This may be especially helpful to image into deep tread grooves.
  • the data clouds from the two IRCUs may be combined (stitched) to create a single data cloud.
  • the system may have markings on the external surfaces to guide an operator during its use.
  • the system may be used with equipment providing visual indication of status such as readiness, fault, or measurement completion.
  • An additional sensor or sensors may be employed in the system to measure the vehicle position and speed as it approaches the camera units. This may trigger the proper timing of the image capture from the IRCUs.
  • the system may operate while the vehicle is in motion.
  • the speed of the IRCU may be capable of capturing the tire in motion without sacrificing resolution.
  • a central unit or Hub may collect data from the IRCUs, perform useful/necessary image processing and data analysis, and present the data to the user.
  • Data from the IRCUs may be transmitted either wirelessly or by wire.
  • the system may include a separate red-green-blue RGB camera unit (either in one of the IRCU housings or elsewhere) to capture the license plate of the vehicle as it rolls past the cameras, then associate the extracted information from the license plate with the data collected from the IRCUs.
  • a separate red-green-blue RGB camera unit (either in one of the IRCU housings or elsewhere) to capture the license plate of the vehicle as it rolls past the cameras, then associate the extracted information from the license plate with the data collected from the IRCUs.
  • Figure 4 illustrates a top-down view of a first configuration according to some embodiments.
  • the top-down view shows the vehicle 401 entering from left and traveling to the right.
  • the tire paths 405a and 405b are shown for illustrative purposes.
  • IRCUs lOla’, lOlb’, lOlc’, and lOld’ are mounted on the floor, positioned on either side of the respective tire paths 40la and 40lb.
  • Cameras are inwardly facing at an angle to provide a useful/optimal view of the respective tire as it passes through the camera’s field of view. Cameras are positioned to ensure the fields of view overlap. Data is collected, analyzed and presented at the Hub.
  • Figure 5 illustrates a top-down view of a second configuration according to some embodiments.
  • the top-down view shows the vehicle 401 entering from left and traveling to the right.
  • the tire paths 405a and 405b are shown for illustrative purposes. In this configuration, there is a dual IRCU lOlbc’ in the center rather than two independent IRCUs.
  • a single or dual camera unit 101 may be
  • Sensors may determine and monitor the tire’s translational speed as it moves down the track.
  • the sled may synchronize its translational speed with that of the tire 115 to maintain a constant working distance for the camera(s) of unit 101.
  • the sled may move ahead or behind the tire 115.
  • the data from the camera(s) may be collected as a time-dependent point cloud.
  • Software may also identify unusual wear patterns indictive of poor alignment, over or under inflation, manufacturing defects, and/or damage.
  • a central unit or Hub may collect data from the camera units, perform useful/necessary image processing and data analysis, and present the data to the user. Data from the camera units may be transmitted either wirelessly or by wire.
  • the system may include an ancillary interface to review data, print output, and/or collect and/or review older data files.
  • This station may reside in the service lane office or other places in a tire or other type of shop.
  • Output from the system may be sent directly to a cloud-based database for future
  • FIG. 6 is a side view illustrating a sensor system in translational sled according to some embodiments.
  • Figure 7 is a front view illustrating a tire 115 shown rolling over an enclosure with a dual optical system (including optical units lOla and lOlb) mounted under that enclosure surface.
  • a respective cone of light l4la and 14 lb from each optical unit lOla and lOlb is shown illuminating the respective tire area of interest.
  • the dual camera systems mounted on a translational sled, may follow (or lead) the tire as it drives the length of the enclosure, capturing video data in the form of a time dependent point cloud.
  • embodiments may be provided using an IRCU 600 (or a plurality of IRCUs), a central control unit 610, and an indicator 620. While separate units are shown by way of example, operations/functions of units may be combined and/or separated in different ways.
  • IRCU 600 may include IR detectors/cameras Dl and D2 as discussed above with respect to Figure 1.
  • IRCU may also include controller 601 and a communication interface 603 (e.g., a wired or wireless communication interface) to provide data from IR detectors/cameras to the central control unit 610.
  • controller 601 and communication interface 603 may provide raw image data from detectors Dl and D2 to central control unit 610
  • controller 601 and communication interface 603 may provide processed point clouds to central control unit 610
  • controller 601 and communication interface 603 may provide tread profile information to central control unit 610.
  • tire position detector 615 e.g., including one or more of an optical sensor(s), a pressure sensor(s), a proximity sensor(s), etc.
  • functionality thereof may be provided within the IRCU or outside of IRCU (e.g., in central control unit 610).
  • IRCU 600 (or portions thereof) may be included in/with a rollover mat.
  • two IRCUs may be used to measure one tire with one IRCU on each side of the tire path (e.g., within a rollover mat or on a drive surface.
  • the IRCU/IRCUs may be provided on a translational sled so that the IRCU/IRCUs move with the rolling tire to capture tire tread information around a circumference of the tire.
  • sources/cameras of Figure 1 may be provided in a manner that allows for the imaging of a tire tread profile.
  • a system to measure a profile of a tread of a tire may include the IR source and cameras (detectors) of Figure 1 provided in a drive-over enclosure as shown in Figures 2/3, 6, and/or 7, with the IR source and cameras positioned to provide an incident view of the incoming tire.
  • an optical opening(s) may be provided in/on a surface of the drive-over enclosure to allow projection of the IR radiation from the IR source to the tire, and reception of reflected IR radiation from the tire at the cameras.
  • Such an optical opening(s) may be provided as: a physical opening(s) with a shutter(s) that opens to allow measurement and that closes to protect the IR source and/or cameras; or a transparent opening(s) (e.g., portions of the enclosure provided with IR transparent glass, plastic, etc.) that allow transmission of source/reflected IR radiation therethrough without physically exposing the IR source/cameras.
  • a physical opening(s) with a shutter(s) that opens to allow measurement and that closes to protect the IR source and/or cameras
  • a transparent opening(s) e.g., portions of the enclosure provided with IR transparent glass, plastic, etc.
  • a system to measure a profile of a tread of a tire may include the IR source and cameras (detectors) of Figure 1 provided in off-axis enclosures as shown in Figure 4 and/or Figure 5.
  • an IRCU with an IR source and two IR cameras may be positioned to provide an angled incident view of an incoming/outgoing tire at a spacing such that a vehicle can pass to the side of the IRCU before/after a tire is imaged.
  • a first IRCU may be provided on one side of a track of a tire and a second IRCU may be provided on the other side of the track of the tire so that the tire travels between the two IRCUs and the profile of the tread is measured based on information from the two IRCUs.
  • a system to measure a profile of a tread of a tire may include the IR source and cameras (detectors) of Figure 1 provided with a translational sled structure as shown in Figure 6.
  • the translational sled structure may be controlled (e.g., using controller 601 and/or 611 of Figure 8) to track at a fixed distance ahead of or behind the rolling tire to measure multiple profiles of the tire tread at different positions around the tire (e.g., around a circumference of the tire).
  • the IR source and cameras may track the tire from below the track of the tire as shown in Figures 2/3/7 (e.g., in front of the tire, behind the tire, or directly beneath the tire), or the IR source and cameras may track the tire from the side of the track of the tire as shown in Figures 3/4 (e.g., in front of the tire or behind the tire).
  • two IR cameras of an IRCU may provide stereoscopic imaging using reflected radiation from one IR source of the IRCU.
  • IR imaging may be performed using an IRCU with one IR source and one IR camera.
  • IR imaging can thus be performed using one illuminator (IR source) and one camera per IRCU providing a field-of-view or using one illuminator (IR source) and 2 cameras in stereo as shown in Figure 1.
  • IR source illuminator
  • IR source illuminator
  • An IRCU with two cameras providing stereoscopic imaging may use an IR source providing an overlapping dot matrix, and an IRCU with a single camera may use an IR source providing a structured pattern for the imaging.
  • the IRCU may be provided in a roll-over structure such that the tire is on the roll-over structure when the IRCU performs imaging.
  • the roll-over structure may be provided as a“speed bump” so that the IRCU performs imaging/measurement before the tire contacts the roll-over structure (before the tire rolls over the structure) or after the tire contacts the roll-over structure (after the tire rolls over the structure).
  • the roll-over structure e.g., referred to as a“speed bump” may rise from the surface on which the tire rolls to position the IR source/cameras to perform imaging/measurement of the tire tread before/after contact between the tire and the structure.
  • Such a structure could have the form of a speed bump that could be used to regulate the speed of the vehicle as the tire is measured. Stated in other words, the use of a speed bump structure could cause the vehicle to slow to an acceptable speed for tread measurement. Such a structure may also provide a benefit that imaging/measurement of the tire tread is performed before (or after) the tire contacts the speed bump structure so that the IRCU is isolated from vibration caused by the vehicle, thereby improving performance.
  • Central control unit 610 also referred to above as a control unit, a Hub, or Hub unit
  • controller 611 and communication interface 6l3a may receive raw image data from ICRU 600, controller 611 and communication interface 613a may receive point cloud information from ICRU 600, and/or controller 611 and communication interface 6l3a may receive processed tread profile information from ICRU 600. Based on information from detectors/cameras Dl and D2, controller 611 may determine an output to be provided to a user/customer of the system, and the output may be provided through communication interface 613b to indicator unit 620. The output may be provided visually through output 625 (e.g., red/yellow/green lights) or printed using output 625 (e.g., a printer). According to some embodiments, functionality of controller 611 may be incorporated in controller 601 and/or controller 621 so that a separate central control unit 610 may not be required.
  • output 625 e.g., red/yellow/green lights
  • Indictor unit 620 may include controller 611 coupled between communication interface 623 and output 625, and output 625 may be implemented as red/yellow/green lights or as a printer. Indicator unit 620 may thus provide an appropriate output based on the profile of the tire. According to some embodiments, functionality of controller 621 may be incorporated in controller 611 and/or controller 601 so that a separate indicator unit is not required.
  • Controller 601 may thus generate tread thickness information (e.g., video information, point cloud information, tread profile information, etc.) based on signals received from detectors/cameras Dl and D2. Tread thickness information may thus be transmitted through wireless/wired communication interface 603 (also referred to as a wireless/wired interface circuit or wireless/wired interface circuitry) to central control unit 610.
  • the communication interface 603 may also receive information (e.g., instructions) from central control unit 610.
  • Controller 611 may receive the tread thickness information from IRCU 600, and controller 611 may use this information to determine an output to be provided using indicator unit 620. Controller 611 may transmit information regarding the output through communication interface 613b to indicator unit 620. Controller 621 may receive the information regarding the output through communication interface 623 and provide the output through output 625, for example, as a one of a red, orange, or green light or as a printout. Communications between interfaces 603 and 613a may be provided via wired and/or wireless interface, and communications between interfaces 613b and 623 may be provided via wired and/or wireless interface.
  • the IR source of Figure 8 may provide infrared (IR) radiation on the tread
  • camera Dl also referred to as an IR detector
  • camera D2 also referred to as an IR detector
  • controller(s) 601/611/621 may measure the profile of the tread, for example, based on the first and second images.
  • the first and second images may be captured and/or selected responsive to tire position detector 615 detecting a location of the tire relative to IRCU 600.
  • controller(s) 601/611/621 may generate a first point cloud based on the first image from camera Dl, and controller(s) 601/611/621 may generate a second point cloud based on the second image from detector/camera D2, and controller(s) 601/611/621 may measure the profile based on the first and second point clouds.
  • the first and second point clouds may be generated responsive to tire position detector 615 detecting a location of the tire relative to the IRCU 600.
  • IRCU 600 may be provided on a translational sled to move with the tire (e.g., ahead of the tire, behind the tire, or below the tire).
  • controller(s) 601/611/621 may control the translational sled to move IRCU 600 including cameras Dl and D2 (also referred to as IR detectors) and the IR source to maintain a measurement distance with respect to the tire as the tire rolls, for example, based on feedback from tire position detector 615.
  • IR source may provide projected IR radiation on the tread while moving to maintain the measurement distance.
  • Camera Dl may generate a plurality of first images at different positions based on IR radiation reflected from the tread while moving to maintain the measurement distance
  • camera D2 may generate a plurality of second images at different positions based on IR radiation reflected from the tread while moving to maintain the measurement distance.
  • Controller(s) 601/611/621 may thus measure a plurality of profiles of the tread at different locations based on the pluralities of first and second images. Controller(s) 601/611/621 may thus measure the plurality of profiles around the circumference of the tire.
  • controller(s) 601/611/621 may generate first and second pluralities of point clouds respectively based on the first and second pluralities of images.
  • controller(s) 601/611/621 may measure the plurality of profiles based on the first and second point clouds. Moreover, the first and second pluralities of images and/or point clouds may be generated responsive to position detector(s) 615 detecting locations of the tire.
  • IRCU 600 including cameras Dl and D2 and the IR source may be provided on the sled below a track for the tire, and cameras Dl and D2 and the IR source may be moved by translating the sled along the track for the tire while the tire rolls on the track.
  • the track may include a portion that is transparent with respect to the IR radiation.
  • cameras Dl and D2, IR source, and the sled may be provided on a level of the track ahead of the tire, behind the tire, and/or offset to a side of a track of the tire.
  • each IRCU may be provided as shown in Figure 8 with two cameras (also referred to as IR detectors) and an IR Source (with elements of the first IRCU-a referred to as Dl-a, IRSource-a, and D2a, and with elements of the second IRCU-b referred to as Dl-b, IRSource-b, and D2-b).
  • a first portion of the tire width may be measured using IRCU-a and a second portion of the tire width may be measured using IRCU-b as shown in Figure 7.
  • IRSource-a may provide first projected infrared (IR) radiation l4la on a first portion of the tread 11 la, camera Dl-a may generate a first image of the tread based on receiving first reflected IR radiation reflected from the tread, and camera Dl-b may generate a second image of the tread based on receiving second reflected IR illumination from the tread.
  • IRSource-b may provide second projected IR radiation 14 lb on a second portion of the tread 11 lb, camera Dl-b may generate a third image of the tread based on receiving third reflected IR radiation reflected from a second portion of the tread, and camera D2-b may generate a fourth image of the tread based on receiving fourth reflected IR
  • controller(s) 601/601 -a/601 -b/611/621 may measure a first portion of the profile corresponding to the first portion of the tread based on the first and second images and may measure a second portion of the profile corresponding to the second portion of the tread based on the third and fourth images.
  • controller(s) 601 /601 - a/60 l-b/611/621 may generate first, second, third, and fourth point clouds respectively based on the first, second, third, and fourth image. Accordingly, controller(s) 601/601 -a/60 l-b/611/621 may measure the first portion of the profile based on the first and second point clouds, and controller(s) 601/601 -a/60 l-b/611/621 may measure the second portion of the profile based on the third and fourth point clouds.
  • first, second, third, and fourth images and/or point clouds may be generated responsive to position detector(s) 615 detecting a location of the tire.
  • the cameras and IR source may be provided below a track for the tire so that the tire rolls over the cameras and the IR source.
  • the track may include a portion that is transparent with respect to the IR radiation to allow projection of the IR from the IR source to the tire and to allow reception of reflected IR radiation at the cameras.
  • the track may include an opening to allow transmission of the IR radiation from the IR source through the opening to the tire and to allow reception of reflected IR radiation at the cameras.
  • controller(s) 601/611/621 may control the shutter to open to allow projection of the IR radiation and generation of the first and second images through the opening, and to close the shutter after generating the first and second images.
  • controller(s) 601/611/621 may provide a visual indication of a status of the tire through output 625 based on measuring the profile of the tread.
  • the visual indication may be one of a red, yellow, or green light to indicate unsafe, marginal, or safe tread condition, or the visual indication may be provided as a graphical, photographic or other representation on a display or a printout.
  • information regarding the profile of the tire may be electronically stored in a local or remote data base or transmitted (e.g., via email) to another location/user/customer.
  • Figure 9 and Figure 10 which is an expanded view of Figure 9) where the IR radiation source and camera(s) 101 are provided in an enclosure 103’ configured to lie on the driving surface (e.g., a garage floor, an outdoor paved surface, etc.).
  • the enclosure 103’ may be provided with the appearance of a“speed bump” with a flat surface configured to lie on the driving surface and with an elevated driving surface opposite the flat surface that may be curved and/or rounded.
  • the driver of the vehicle may naturally slow the vehicle approaching the enclosure, and/or the driver may be more comfortable driving over the enclosure.
  • the camera and/or IR radiation source 101 may be oriented in the enclosure 103’ so that a line of sight of the camera(s) and/or the IR radiation source extends through an optical opening through the elevated driving surface.
  • the enclosure may be configured to orient the line of sight of the camera(s) and/or the IR radiation source at an acute angle relative to the driving surface.
  • a pneumatic air source 1031 may be provided in the enclosure 103’, with the pneumatic air source being configured to clear an optical path for the IR radiation source and/or the camera.
  • an optically transparent protective cover 1041 (shown as protective glass in Figure 10) may be provided within the enclosure in the line of sight, and the pneumatic air source may be an air knife configured to clean a surface of the optically transparent protective cover.
  • the surface of the optically transparent cover may be provided at an angle that is non parallel with respect to the flat surface of the enclosure so that contaminants (e.g., dirt, fluids, etc.) do not settle easily on the surface.
  • contaminants e.g., dirt, fluids, etc.
  • the image of the tire may be captured by the camera(s) as the tire approaches the enclosure before the tire contacts the enclosure.
  • a structure similar to that of Figures 9 and 10 may be configured to capture the image of the tire after the tire rolls over the enclosure (e.g., reversing the directions of movement/rotation of the tire as shown in Figures 9 and 10).
  • IRCU 600 (or portions thereof) may be included in/with the“speed bump” enclosure.
  • the terms “comprise”, “comprising”, “comprises”, “include”, “including”, “includes”, “have”, “has”, “having”, or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof.
  • the common abbreviation “e.g.”, which derives from the Latin phrase “exempli gratia” may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item.
  • the common abbreviation “i.e.”, which derives from the Latin phrase “id est,” may be used to specify a particular item from a more general recitation.
  • top when an upper part of a drawing is referred to as a "top” and a lower part of a drawing is referred to as a “bottom” for the sake of convenience, in practice, the "top” may also be called a “bottom” and the “bottom” may also be a “top” without departing from the teachings of the inventive concept (e.g., if the structure is rotate 180 degrees relative to the orientation of the figure).
  • Example embodiments are described herein with reference to block diagrams and/or flowchart illustrations of computer-implemented methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits.
  • These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit, and/or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions/acts specified in the block diagrams and/or flowchart block or blocks, and thereby create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block(s).

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Mechanical Engineering (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

La présente invention porte, selon certains modes de réalisation, sur des procédés destinés à mesurer un profil d'une bande de roulement d'un pneu. Selon de tels procédés, le profil de la bande de roulement peut être mesuré sur la base d'une caméra recevant un rayonnement infrarouge (IR) réfléchi par la bande de roulement. Selon certains autres modes de réalisation, la présente invention se rapporte à des systèmes destinés à mesurer un profil d'une bande de roulement d'un pneu. De tels systèmes peuvent comprendre une source de rayonnement infrarouge (IR), une caméra et un dispositif de commande couplé à la caméra. La source de rayonnement infrarouge (IR) peut être configurée pour projeter un rayonnement IR sur la bande de roulement. La caméra peut être configurée pour générer une image de la bande de roulement sur la base de la réception d'une réflexion du rayonnement IR réfléchi par la bande de roulement. Le dispositif de commande peut être couplé à la caméra, le dispositif de commande étant configuré pour mesurer le profil de la bande de roulement sur la base de l'image générée par la caméra.
PCT/US2019/057623 2018-10-25 2019-10-23 Procédés et systèmes utilisés pour mesurer des bandes de roulement de pneu WO2020086698A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201862750478P 2018-10-25 2018-10-25
US62/750,478 2018-10-25
US201862773561P 2018-11-30 2018-11-30
US62/773,561 2018-11-30

Publications (1)

Publication Number Publication Date
WO2020086698A1 true WO2020086698A1 (fr) 2020-04-30

Family

ID=70330742

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2019/057623 WO2020086698A1 (fr) 2018-10-25 2019-10-23 Procédés et systèmes utilisés pour mesurer des bandes de roulement de pneu

Country Status (1)

Country Link
WO (1) WO2020086698A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210372777A1 (en) * 2020-05-28 2021-12-02 The Goodyear Tire & Rubber Company System and method for estimating tire tread depth
WO2022070176A1 (fr) * 2020-09-30 2022-04-07 Uveye Ltd. Système d'estimation de la profondeur de la bande de roulement et procédé correspondant
US11614317B2 (en) 2019-06-21 2023-03-28 Tyrata, Inc. Methods providing enhanced material thickness sensing with capacitive sensors using inductance-generated resonance and related devices
US11673436B2 (en) 2018-06-29 2023-06-13 Tyrata, Inc. Structures and methods providing tread sensor integration

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010022802A1 (en) * 2000-03-17 2001-09-20 Bridgestone Corporation Tire wear forecasting method and apparatus
US20120207340A1 (en) * 2011-02-14 2012-08-16 Xerox Corporation Method for automated tire detection and recognition
US20130099123A1 (en) * 2010-06-15 2013-04-25 Societe De Technologie Michelin Tire surface anomaly detection
US20130278771A1 (en) * 2011-06-10 2013-10-24 Flir Systems, Inc. Systems and methods for monitoring vehicle wheel assembly
US20170124784A1 (en) * 2014-06-19 2017-05-04 Neomatix Ltd. System and method for multiple feature detection and analysis of a rotating tire
US9677973B1 (en) * 2013-02-22 2017-06-13 Hunter Engineering Company Method and apparatus for environmental protection of drive-over tire tread depth optical sensors
US9805697B1 (en) * 2012-06-01 2017-10-31 Hunter Engineering Company Method for tire tread depth modeling and image annotation
EP3243671A1 (fr) * 2016-05-11 2017-11-15 Conti Temic microelectronic GmbH Procédé et appareil de classification d'un pneu
KR102002450B1 (ko) * 2017-11-28 2019-07-22 공주대학교 산학협력단 차량의 타이어 마모 감지 장치

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010022802A1 (en) * 2000-03-17 2001-09-20 Bridgestone Corporation Tire wear forecasting method and apparatus
US20130099123A1 (en) * 2010-06-15 2013-04-25 Societe De Technologie Michelin Tire surface anomaly detection
US20120207340A1 (en) * 2011-02-14 2012-08-16 Xerox Corporation Method for automated tire detection and recognition
US20130278771A1 (en) * 2011-06-10 2013-10-24 Flir Systems, Inc. Systems and methods for monitoring vehicle wheel assembly
US9805697B1 (en) * 2012-06-01 2017-10-31 Hunter Engineering Company Method for tire tread depth modeling and image annotation
US9677973B1 (en) * 2013-02-22 2017-06-13 Hunter Engineering Company Method and apparatus for environmental protection of drive-over tire tread depth optical sensors
US20170124784A1 (en) * 2014-06-19 2017-05-04 Neomatix Ltd. System and method for multiple feature detection and analysis of a rotating tire
EP3243671A1 (fr) * 2016-05-11 2017-11-15 Conti Temic microelectronic GmbH Procédé et appareil de classification d'un pneu
KR102002450B1 (ko) * 2017-11-28 2019-07-22 공주대학교 산학협력단 차량의 타이어 마모 감지 장치

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11673436B2 (en) 2018-06-29 2023-06-13 Tyrata, Inc. Structures and methods providing tread sensor integration
US11614317B2 (en) 2019-06-21 2023-03-28 Tyrata, Inc. Methods providing enhanced material thickness sensing with capacitive sensors using inductance-generated resonance and related devices
US20210372777A1 (en) * 2020-05-28 2021-12-02 The Goodyear Tire & Rubber Company System and method for estimating tire tread depth
US11421982B2 (en) * 2020-05-28 2022-08-23 The Goodyear Tire & Rubber Company System and method for estimating tire tread depth
WO2022070176A1 (fr) * 2020-09-30 2022-04-07 Uveye Ltd. Système d'estimation de la profondeur de la bande de roulement et procédé correspondant
US11562472B2 (en) 2020-09-30 2023-01-24 Uveye Ltd. System of tread depth estimation and method thereof

Similar Documents

Publication Publication Date Title
WO2020086698A1 (fr) Procédés et systèmes utilisés pour mesurer des bandes de roulement de pneu
CN100592029C (zh) 测距设备
US9858682B2 (en) Device for optically scanning and measuring an environment
JP6387407B2 (ja) 周辺検知システム
KR101030763B1 (ko) 이미지 획득 유닛, 방법 및 연관된 제어 유닛
US20170280132A1 (en) System and method of acquiring three-dimensional coordinates using multiple coordinate measurment devices
KR101927648B1 (ko) 차량 운행 고장 검출 시스템 및 방법
US20100060885A1 (en) Method and device for performing optical suspension measurement
US20140168380A1 (en) Device for optically scanning and measuring an environment
JP2018537655A (ja) タイヤ状態解析
US20130258108A1 (en) Road Surface Shape Recognition System and Autonomous Mobile Apparatus Using Same
US11073379B2 (en) 3-D environment sensing by means of projector and camera modules
JP2009041929A (ja) 距離計測方法および装置、ならびに距離計測装置を備えた車両
JP2007527007A (ja) 移動制御システム
KR20160096000A (ko) 2개의 물체의 목표 위치 편차를 결정하기 위한 장치 및 방법
CN104777521A (zh) 一种基于双目视觉的列车车门与站台屏蔽门之间异物检测系统及其检测方法
US20200408682A1 (en) Optical Wheel Evaluation
CN104215200A (zh) 利用多波长进行表面同步三维测量的装置及方法
CN102887155A (zh) 货运列车超限计算机视觉检测系统
EP4204847A1 (fr) Détection de rétroréflecteurs dans des images du nir pour commander un balayage lidar
KR100844640B1 (ko) 물체 인식 및 거리 계측 방법
CN112672017B (zh) 测试结构件、ToF装置以及镜头脏污检测方法
KR101679017B1 (ko) Hud에서 가상이미지를 생성하는 장치 및 방법
WO2018002679A1 (fr) Procédé d'identification et de localisation d'un objet mobile
CN115769258A (zh) 用于漫射照明和结构光的投影仪

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19876406

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19876406

Country of ref document: EP

Kind code of ref document: A1