WO1994015173A1 - Detecteur de balayage - Google Patents

Detecteur de balayage Download PDF

Info

Publication number
WO1994015173A1
WO1994015173A1 PCT/GB1993/001844 GB9301844W WO9415173A1 WO 1994015173 A1 WO1994015173 A1 WO 1994015173A1 GB 9301844 W GB9301844 W GB 9301844W WO 9415173 A1 WO9415173 A1 WO 9415173A1
Authority
WO
WIPO (PCT)
Prior art keywords
scanning device
laser
scanning
stripe
optics
Prior art date
Application number
PCT/GB1993/001844
Other languages
English (en)
Inventor
Stephen Crampton
Original Assignee
3D Scanners Ltd.
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
Priority claimed from GB9226426A external-priority patent/GB2264601A/en
Application filed by 3D Scanners Ltd. filed Critical 3D Scanners Ltd.
Priority to AU49723/93A priority Critical patent/AU4972393A/en
Publication of WO1994015173A1 publication Critical patent/WO1994015173A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G01B11/25—Measuring 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

Definitions

  • This invention relates to a sensing device for the accurate, three dimensional surface scanning of an object.
  • a m ⁇ ar;h*TH ⁇ ai sensor such as a touch-trigger probe mounted on a Coordinate Measuring Machine (CMM) .
  • CCM Coordinate Measuring Machine
  • a typical scan rate is 2 to 10 points per second. Since the touch-trigger probe is at a fixed vertical orientation, areas of the surface that are steeper than 3 degrees from the vertical usually cannot be scanned. Soft objects cannot be scanned accurately since the mechanical probe deforms the surface of the object on touching it.
  • optical single point probes based on laser triangulation have been used. These probes triangulate with one viewpoint which is normally a position sensing diode or a linear CCD sensor. They have higher scan rates than mechanical sensors since they are non-contacting and have no problem in scanning soft objects. However, optical single point probes cannot scan all surface textures and colours. There are also problems in scanning discontinuities such as edges. In addition, the path between the spot of laser light on the surface and the sensing device is sometimes obscured by the geometry of the object, causing an effect called shadowing (or eclipsing) in which measurements are lost. Disclosure of Invention
  • the scanning sensor is connected by a cable to a special control and processing unit.
  • a scanning sensor which projects two stripes of laser light and views these two stripes from two viewpoints using the viewing means. There is relative movement between the scanning sensor and the object being scanned.
  • the scanning sensor typically weighs around one kilogramme and would normally measure less than 300mm in size in any dimension.
  • the use of laser stripes and matrix CCD arrays rather than a single point with a linear CCD array or position sensing diode means that several hundred measurements may be made along the stripe simultaneously.
  • the largest delay in scanning is the physical movement of the object relative to the scanner between each measuring position.
  • the making of several hundred measurements at each position instead of one measurement at each position has several bene its.
  • the scanning sensor has a faster data collection rate.
  • the scanning machine with a laser stripe need make only a few traverses to scan the whole object to a uniform density, rather than several hundred or thousand traverses as required by a single point sensor.
  • the use of a laser stripe enables measurements to be made on vertical an slightly overhanging surfaces in the direction along the laser stripe.
  • a CCD matrix rather than an area position sensing device or a linear position sensing device with a scanned spot/viewing point enables the processing unit to apply algorithms based on the knowledge of the light levels at each point in the matrix. These algorithms can determine not only the position but can identify well-known situations when errors in position are likely and to either output error signals or to compute accurate positions taking into account the full data. Position sensing devices do this process in hardware with the disadvantage that false positions may be generated due to optical effects such as those found at the edge of an object when part of the projected light is lost or from flare and reflections at a shoulder. The position sensing device cannot output error signals or provide the raw data that a CCD matrix can for calculating a more accurate position.
  • the two laser stripe generators are oriented towards each other. This enables surfaces that are vertical or slightly overhanging in the direction of scanning to be scanned.
  • the laser stripe generators may be individually controlled such that each matrix CCD array exposure may contain light from either one or both stripes. In some complex surfaces the ability to have light from just one stripe at a time can avoid confusion in the processing if the two stripes meet in the CCD array i age.
  • Laser projection optics are used to provide a laser stripe that is typically less than lOO ⁇ m in width.
  • the laser projection optics typically include focusing and defocu ⁇ ing elements, together with a stripe generating element.
  • the laser sources may be broadband or narrow-band.
  • the use of a broadband laser source can overcome some optical characteristics generated by the surface texture.
  • An example is the generation of speckle patterns by the interaction of a narrowband source with a machined surface. The speckles thus produced distort the stripe such that any measurements made are significantly less accurate than without the speckle effect.
  • the provision of two view points may be achieved by means of two CCD matrix arrays or by one CCD matrix array and four mirrors.
  • the two view points overcome most shadowing problems in that if a part of the laser stripe is obscured from one viewpoint, then it is often visible from the other viewpoint.
  • the scanning sensor may be traversed in either direction perpendicular to the stripe and due to its symmetry will achieve the same results. This is not true for one viewpoint due to shadowing nd the scanning sensor is thus more flexible in use with two viewpoints than with one viewpoint.
  • a processing unit would typically calculate the centre of the stripe at each point to sub-pixel accuracy by using algorithms such as centre of gravity interpolation. It would also control laser powers and CCD matrix array exposures by real-time processing of the previous exposure.
  • the processing unit may be used to generate move commands to a machine that will change the relative distance between the object and the scanning sensor, allowing for the adaptive scanning of objects in which the variation in height of the object's surface is greater than the depth range of the scann ng sensor.
  • the lead stripe can provide advance information before the trailing stripe passes, allowing for the trailing stripe to be moved into range to scan what the lead stripe may have missed. This information can be used to generate the increment to the next scanning traverse.
  • the scan increments between the traverses may be much less than on an object that is realtively flat; the gene-ration of scan increments may be carried out adaptively and the increment can be changed so as to vary along a traverse.
  • the scanning sensor is fast and for an ideal object, data capture speeds of more than 12,000 measurements per second are obtainable.
  • the scanning sensor which is the subject of this invention is novel in that the unique combination and orientation of the CCD matrix array, laser and optical components into one scanning sensor provide a sensing device that is highly effective in accurately scanning an object more completely and more rapidly than other sensors available on the market.
  • Figure 1 is an outline of the scanning sensor layout.
  • a scanning device [2] comprising a camera [4] , a laser stripe generating means [3] , comprising laser optics [7] , and at least one mirror [6] , characterised in that the scanning device [2] projects at least two stripes of laser light [10] and has at least two viewing means.
  • the object being scanned [l] moves relative to the scanning sensor [2] .
  • the scanning sensor is a rigid enclosure to which the components [3,4,5,6,7] are firmly attached such that there is no scope for movement of the components [3,4,5,6,7] relative to each other in normal operation.
  • the scanning sensor operates on the principal of structured light triangulation.
  • the sources of structured light are usually two lasers [3] at an angle towards each other, but may be one laser and an optical arrangement of mirrors and beam splitters.
  • the source could be a slit of light or any other source that projects a relatively thin stripe of light onto the object [1] .
  • the light stripe( ⁇ ) are viewed at an angle by at least one CCD matrix array camera [4] .
  • Camera optics [5] may be used to change the field of view.
  • the preferred method is a lens of fixed focal length.
  • Anamorphic optics in which the focal length in orthogon l directions is variable may also be used.
  • the CCD matrix array camera( ⁇ ) may not view the object directly and instead their optical paths may include reflection by means of a system of mirrors [6] .
  • Laser optics [7] may be used in conjunction with the laser to produce stripes of different thicknesses.
  • One method is to use a rod lens, which spreads a beam of light into a stripe of light.
  • the rod lens may be used in conjunction with focusing optics to focus the thickness of the stripe at a certain distance from the optics.
  • a second method is the use of a scanning element such as a polygon mirror or galvanometer mirror to scan a spot to produce a stripe.
  • the scanning sensor [2] has the capability of measuring points on the undercut surface of slight overhangs on the object [1] in the direction of the stripe.
  • the lines of sight [9] are shown.
  • the scans can be overlapped so that no information is lost by shadowing along the stripe. Overlapping of the traverses by up to two thirds is enough to capture the vertical surfaces and slight overhangs along the stripe. In practice, the overlap could be much le ⁇ s than this.
  • An alternative scanning strategy is to scan the entire object with a very small overlap between traverses and from this information, the processing unit can identify the areas where data is missing and generate commands to the machine to go back and scan these areas until the complete surface is captured.
  • the scanning sensor [2] has the capability of measuring points on the undercut surface of slight overhangs on the object [1] in the direction of scanning.
  • the lines of laser light [10] are shown.
  • FIG. l A configuration for the sensor is shown in Figure l. The way in which this configuration may be used is indicated in Figures 2 and 3. This configuration is only one of several modes for carrying out the invention.
  • the main uses are in reverse engineering and inspection. Examples of the main uses are: the reverse engineering of a model with free-form surface shapes for the production of tooling at a different scale to the original and the inspection of discrete products for the provision of pass/fail and trend information.

Abstract

Dispositif (2) de balayage comprenant au moins une caméra (4), un générateur (3) de fasceau laser qui est constitué d'une optique laser (7) et qui produit deux faisceaux de lumière laser, et un processeur (5) de données. Le dispositif (2) de balayage comprend au moins deux systèmes de visualisation constitués soit par au moins deux caméras (4) soit associés à des miroirs ou des lentilles. Le générateur (3) de faisceau laser et les systèmes de visualisation sont placés les uns par rapport aux autres de sorte que des zones situées sur la surface d'objets qui seraient dans l'ombre si on utilisait une seule incidence de lumière laser, puissent être vues directement par le générateur (3) de faisceau laser et par les systèmes de visualisation.
PCT/GB1993/001844 1992-12-18 1993-08-31 Detecteur de balayage WO1994015173A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU49723/93A AU4972393A (en) 1992-12-18 1993-08-31 Scanning sensor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9226426A GB2264601A (en) 1991-12-31 1992-12-18 Object inspection
GB9226426.6 1992-12-18

Publications (1)

Publication Number Publication Date
WO1994015173A1 true WO1994015173A1 (fr) 1994-07-07

Family

ID=10726831

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1993/001844 WO1994015173A1 (fr) 1992-12-18 1993-08-31 Detecteur de balayage

Country Status (2)

Country Link
AU (1) AU4972393A (fr)
WO (1) WO1994015173A1 (fr)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5778724A (en) * 1995-09-07 1998-07-14 Minnesota Mining & Mfg Method and device for monitoring web bagginess
ES2116927A1 (es) * 1996-09-20 1998-07-16 Tecnologico Robotiker Centro Escaner tridimensional.
AU715218B2 (en) * 1994-08-24 2000-01-20 Tricorder Technology Plc Scanning arrangement and method
US6553138B2 (en) 1998-12-30 2003-04-22 New York University Method and apparatus for generating three-dimensional representations of objects
US6920697B2 (en) 2002-02-14 2005-07-26 Faro Technologies, Inc. Portable coordinate measurement machine with integrated touch probe and improved handle assembly
DE19581099B4 (de) * 1994-09-28 2006-07-27 William Richard Fright Optisches Oberflächenabtastgerät und Vermessungsverfahren
USRE42082E1 (en) 2002-02-14 2011-02-01 Faro Technologies, Inc. Method and apparatus for improving measurement accuracy of a portable coordinate measurement machine
US7903245B2 (en) 2007-08-20 2011-03-08 Marc Miousset Multi-beam optical probe and system for dimensional measurement
WO2011032999A1 (fr) 2009-09-15 2011-03-24 Mettler-Toledo Ag Appareil permettant de mesurer les dimensions d'un objet
DE102006036586B4 (de) * 2006-08-04 2011-06-22 Reiter, Mathias, Dipl.-Ing., 82515 Lötnahtprüfung
EP2623010A3 (fr) * 2012-02-04 2014-09-24 LG Electronics, Inc. Robot nettoyeur
US8931182B2 (en) 2002-02-14 2015-01-13 Faro Technologies, Inc. Portable coordinate measurement machine having a handle that includes electronics
US8988523B1 (en) * 2013-03-01 2015-03-24 The United States Of America, As Represented By The Secretary Of Agriculture Single-camera multi-mirror imaging method and apparatus for whole-surface inspection of rotating objects
US20160212412A1 (en) * 2013-09-18 2016-07-21 Matter and Form Inc. Device, system and method for three-dimensional modeling
US9568438B1 (en) * 2013-03-01 2017-02-14 The United States Of America, As Represented By The Secretary Of Agriculture Single-camera angled conveyance imaging method and apparatus for whole-surface inspection of rotating objects
DE102017007590A1 (de) * 2017-08-11 2019-02-14 Baumer Inspection Gmbh Verfahren und Vorrichtung zur Erfassung von dreidimensionalen Objekten auf Basis des Lichtschnittverfahrens

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2536696A1 (de) * 1975-08-18 1977-03-03 Betr Forsch Inst Angew Forsch Verfahren und vorrichtung fuer die bestimmung der querschnittsformen von koerpern auf optischem wege
EP0062941A1 (fr) * 1981-04-08 1982-10-20 Koninklijke Philips Electronics N.V. Dispositif d'enregistrement mesure de contours
EP0130345A2 (fr) * 1983-06-02 1985-01-09 General Electric Company Dispositif intégré de caméra et d'éclairage
US4541722A (en) * 1982-12-13 1985-09-17 Jenksystems, Inc. Contour line scanner
JPS60196608A (ja) * 1984-03-21 1985-10-05 Tomohiko Akuta 三次元形状の自動測定方法
JPS61162706A (ja) * 1985-01-14 1986-07-23 Hitachi Zosen Corp 立体計測方法
WO1987001194A1 (fr) * 1985-08-12 1987-02-26 David Andrew Addleman Numeriseur rapide de surfaces tridimensionnelles
US4741621A (en) * 1986-08-18 1988-05-03 Westinghouse Electric Corp. Geometric surface inspection system with dual overlap light stripe generator
EP0305107A2 (fr) * 1987-08-24 1989-03-01 L.B.P. Partnership Appareil à balayage tridimensionnel

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2536696A1 (de) * 1975-08-18 1977-03-03 Betr Forsch Inst Angew Forsch Verfahren und vorrichtung fuer die bestimmung der querschnittsformen von koerpern auf optischem wege
EP0062941A1 (fr) * 1981-04-08 1982-10-20 Koninklijke Philips Electronics N.V. Dispositif d'enregistrement mesure de contours
US4541722A (en) * 1982-12-13 1985-09-17 Jenksystems, Inc. Contour line scanner
EP0130345A2 (fr) * 1983-06-02 1985-01-09 General Electric Company Dispositif intégré de caméra et d'éclairage
JPS60196608A (ja) * 1984-03-21 1985-10-05 Tomohiko Akuta 三次元形状の自動測定方法
JPS61162706A (ja) * 1985-01-14 1986-07-23 Hitachi Zosen Corp 立体計測方法
WO1987001194A1 (fr) * 1985-08-12 1987-02-26 David Andrew Addleman Numeriseur rapide de surfaces tridimensionnelles
US4741621A (en) * 1986-08-18 1988-05-03 Westinghouse Electric Corp. Geometric surface inspection system with dual overlap light stripe generator
EP0305107A2 (fr) * 1987-08-24 1989-03-01 L.B.P. Partnership Appareil à balayage tridimensionnel

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 10, no. 369 (P - 525) 10 December 1986 (1986-12-10) *
PATENT ABSTRACTS OF JAPAN vol. 10, no. 52 (P - 432) 28 February 1986 (1986-02-28) *

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU715218B2 (en) * 1994-08-24 2000-01-20 Tricorder Technology Plc Scanning arrangement and method
DE19581099B4 (de) * 1994-09-28 2006-07-27 William Richard Fright Optisches Oberflächenabtastgerät und Vermessungsverfahren
US5778724A (en) * 1995-09-07 1998-07-14 Minnesota Mining & Mfg Method and device for monitoring web bagginess
ES2116927A1 (es) * 1996-09-20 1998-07-16 Tecnologico Robotiker Centro Escaner tridimensional.
US6553138B2 (en) 1998-12-30 2003-04-22 New York University Method and apparatus for generating three-dimensional representations of objects
US9410787B2 (en) 2002-02-14 2016-08-09 Faro Technologies, Inc. Portable coordinate measurement machine having a bearing assembly with an optical encoder
US8931182B2 (en) 2002-02-14 2015-01-13 Faro Technologies, Inc. Portable coordinate measurement machine having a handle that includes electronics
US6935036B2 (en) 2002-02-14 2005-08-30 Faro Technologies, Inc. Portable coordinate measurement machine
USRE42082E1 (en) 2002-02-14 2011-02-01 Faro Technologies, Inc. Method and apparatus for improving measurement accuracy of a portable coordinate measurement machine
US7043847B2 (en) 2002-02-14 2006-05-16 Faro Technologies, Inc. Portable coordinate measurement machine having on-board power supply
US10168134B2 (en) 2002-02-14 2019-01-01 Faro Technologies, Inc. Portable coordinate measurement machine having a handle that includes electronics
US9513100B2 (en) 2002-02-14 2016-12-06 Faro Technologies, Inc. Portable coordinate measurement machine having a handle that includes electronics
US6920697B2 (en) 2002-02-14 2005-07-26 Faro Technologies, Inc. Portable coordinate measurement machine with integrated touch probe and improved handle assembly
DE102006036586B4 (de) * 2006-08-04 2011-06-22 Reiter, Mathias, Dipl.-Ing., 82515 Lötnahtprüfung
US7903245B2 (en) 2007-08-20 2011-03-08 Marc Miousset Multi-beam optical probe and system for dimensional measurement
WO2011032999A1 (fr) 2009-09-15 2011-03-24 Mettler-Toledo Ag Appareil permettant de mesurer les dimensions d'un objet
US8520220B2 (en) 2009-09-15 2013-08-27 Mettler-Toledo Ag Apparatus for measuring the dimensions of an object
CN102498363A (zh) * 2009-09-15 2012-06-13 梅特勒-托利多公开股份有限公司 测量物体尺寸的设备
EP2623010A3 (fr) * 2012-02-04 2014-09-24 LG Electronics, Inc. Robot nettoyeur
US8988523B1 (en) * 2013-03-01 2015-03-24 The United States Of America, As Represented By The Secretary Of Agriculture Single-camera multi-mirror imaging method and apparatus for whole-surface inspection of rotating objects
US9568438B1 (en) * 2013-03-01 2017-02-14 The United States Of America, As Represented By The Secretary Of Agriculture Single-camera angled conveyance imaging method and apparatus for whole-surface inspection of rotating objects
US20160212412A1 (en) * 2013-09-18 2016-07-21 Matter and Form Inc. Device, system and method for three-dimensional modeling
US9900585B2 (en) * 2013-09-18 2018-02-20 Matter and Form Inc. Device, system and method for three-dimensional modeling
DE102017007590A1 (de) * 2017-08-11 2019-02-14 Baumer Inspection Gmbh Verfahren und Vorrichtung zur Erfassung von dreidimensionalen Objekten auf Basis des Lichtschnittverfahrens
DE102017007590B4 (de) * 2017-08-11 2019-06-06 Baumer Inspection Gmbh Verfahren und Vorrichtung zur Erfassung von dreidimensionalen Objekten auf Basis des Lichtschnittverfahrens

Also Published As

Publication number Publication date
AU4972393A (en) 1994-07-19

Similar Documents

Publication Publication Date Title
GB2264601A (en) Object inspection
US8670114B2 (en) Device and method for measuring six degrees of freedom
US5082362A (en) Zoom lens for a variable depth range camera
EP2183544B1 (fr) Appareil et procédé de mesure sans contact
US4979815A (en) Laser range imaging system based on projective geometry
US4299491A (en) Noncontact optical gauging system
GB2264602A (en) Object examination
WO1994015173A1 (fr) Detecteur de balayage
US5061062A (en) Focus spot size controller for a variable depth range camera
US5032023A (en) Optical fiber based sensor for a variable depth range camera
WO1993008448A1 (fr) Systeme rapide de mesure de surfaces en trois d, d'inspection de surfaces et de cao inversee
IE42799B1 (en) Gauging system for determining the contour of the surface of an object
JP7339629B2 (ja) 複数のレーザーガルバノスキャナを用いる空間曲線の共同位置決め投影システム、及び、その方法
EP1680689B1 (fr) Dispositif de balayage d'objets tridimensionnels
Matos et al. Underwater laser triangulation sensor model with flat refractive interfaces
US11276198B2 (en) Apparatus for determining dimensional and geometric properties of a measurement object
US6927864B2 (en) Method and system for determining dimensions of optically recognizable features
US5568258A (en) Method and device for measuring distortion of a transmitting beam or a surface shape of a three-dimensional object
Manthey et al. Calibration of a laser range-finding coordinate-measuring machine
JPH06249624A (ja) ３次元表面形状測定装置
JPH08504505A (ja) 離れた像を撮像する方法および装置
KR20040071532A (ko) 3차원형상 측정장치
US4725146A (en) Method and apparatus for sensing position
Tu et al. Geometrical model of laser triangulation system based on synchronized scanners
Clark et al. Measuring range using a triangulation sensor with variable geometry

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AT AU BR CA CH CZ DE DK ES GB JP KR NL NO NZ PL PT RU SE UA US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA