WO1989012837A1 - Dispositif de telemetrie - Google Patents

Dispositif de telemetrie Download PDF

Info

Publication number
WO1989012837A1
WO1989012837A1 PCT/AU1989/000263 AU8900263W WO8912837A1 WO 1989012837 A1 WO1989012837 A1 WO 1989012837A1 AU 8900263 W AU8900263 W AU 8900263W WO 8912837 A1 WO8912837 A1 WO 8912837A1
Authority
WO
WIPO (PCT)
Prior art keywords
scene
light source
image data
image
range finding
Prior art date
Application number
PCT/AU1989/000263
Other languages
English (en)
Inventor
Kemal Ajay
Original Assignee
Kemal Ajay
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 Kemal Ajay filed Critical Kemal Ajay
Publication of WO1989012837A1 publication Critical patent/WO1989012837A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging

Definitions

  • This invention relates to optical radar systems, and more particularly to systems which acquire range data points in a parallel or simultaneous fashion, rather than point by point using a scanning mechanism.
  • the invention has particular utility in robotics where it is necessary for a robot to obtain a "picture" of the surrounding and consequently the invention i generally applicable over only a short range.
  • U.S. Patent No. 3,899,250 discloses a system where the delay between the outgoing pulse and receiver activation is controlled on successive pulse cycles, to give a known correction for sensitivity with distance.
  • French, U.S. Patent No. 4,226,529 presents a viewing system whereby the contrast of an image of a target at a particular distance is enhanced with the time gating adjustable to view different ranges.
  • U.S. Patent No. 4,603,250 discloses a viewing system in which an image intensifier is used as the receiver ⁇ with the photocathode gated and the gain of the receiver adjusted by varying the microchannel plate voltage.
  • Each diode is activated in turn and the time taken for light to travel from the source to the reflecting object and back to the photodiode is measured.
  • the echo time gives the time of flight, and hence distance, to the object in the scene that the particular diode is focused upon.
  • an optical radar range finding system comprising a high speed switchable light source for illuminating a scene, a high speed switchable imagin device for receiving a reflected image from said scene and providing an output to control means, a pulsing means connected to said light source and to said imaging device to provide pulses to trigger said light source and said imaging device, respectively, said control -means including a store means for storing image information from said imaging device, control logic to sequence operation of said light source and logic circuitry to process data and produce range information relevan to said scene.
  • said control logic operates a switching device and the switching device is able to switch said light source to be continuously on, triggered by said pulsing means or in an off condition.
  • said light source is a laser diode array.
  • the store means is a video frame store.
  • Another broad form of the invention provides a method of obtaining range information relating to a scene comprising the steps of:
  • said method includes the further step of storing third image data reflected from the scene in the absence of light from the light source and subtracting the third image dat from the first and second image data, respectively, prior to said division so as to remove background illumination effects.
  • Figure 1 is a simplified block diagram of apparatus constitutin the system.
  • Figure 2 shows time profiles of reflected light pulses and sensitivity of the image sensor, of the system of Figure 1.
  • Figures 3 and 4 show plan view and side view, respectively, of experimental apparatus used to demonstrate the apparatus.
  • Figure 5 shows the range image acquired from the system when viewing the apparatus of Figures 3 and 4.
  • Figure 6 shows a profile of distances for a horizontal section through Figure 5.
  • FIG. 7 is a more detailed block diagram of the apparatus of Figure 1.
  • Figure 8 is a timing diagram showing timing details of the system's hardware.
  • Figure 9 shows graphs of the approximate output of laser diode array, and the image intensifier sensitivity, respectively.
  • control hardware 1 selects switch 2 so that the high speed light source 3 is pulsed on and off by the pulse generator 4.
  • the pulse generator 4 also drives circuitry (not shown in Figure 1) that controls the sensitivity of image sensor 5.
  • the resulting image is stored in the contro hardware 1.
  • the reference 6 represents a video monitor.
  • control hardware 1 selects switch 2 so that the light source is continuously on.
  • the resulting image from the image sensor is again stored in the control hardware 1.
  • the intensity of the image is dependent upon the distance to the objects, due to the inverse square law.
  • the image is also dependent upon a gating effect caused by the overlap of the reflected light pulse from the scene with the 'on' time of the image sensor, again depende on distance.
  • .12 is taken when the light source is continuously on and is dependent only on the surface reflectivity of objects in the scene.
  • the intensity of the image is dependent upon the distan to the objects, caused by the inverse square law.
  • R is a range image and K is a calibration factor which is constant.
  • This processing removes the effect of surface reflectivity and inverse square light loss.
  • the only effect that remains is tha due to the overlap or convolution of the pulsed light with the gated image sensor.
  • the convolution value depends on the delay between the onset of the reflected pulse at the receiver, and the onset of the activation of the image sensor. This delay is due to the round trip time for light to travel from the pulsed light source, to the objects in the scene and back to the image sensor 5. Thus, for any pixel in the range, knowing the shape of the convolution function and the overall calibration factor K, the distance from the rangefinder to any point in the image may be found directly from R.
  • the calibration factor, K is globally applied to all points in the image and may be found by obtaining a range image of a scene of known dimensions. This need be done only once.
  • a refinement of the above mode of operation, to facilitate operation in non-ideal environments, is the extension of the control hardware to capture a third 'background' image to includ in the processing. This image is taken with the light source turned off so that background illumination effects are recorded. The processing is modified so that
  • the experiment used to demonstrate the system comprises six test cards A separated from each other by 15 cm.
  • the receiver 5 is 115 cm from the closet test card A.
  • the cards are also offset transversely to the direction of light source.
  • Figure 5 shows the range image acquired using such apparatus and
  • Figure 6 shows a profile of distances to the various cards on a horizontal section through the image of Figure 5.
  • a pulse generator 11 provides timed trigger signa to the image intensifier driver 12 which drives the gate of the image intensifier 9.
  • the pulse generator also triggers the las diode array and associated drive circuitry 17.
  • the laser diode used are the SHARP LT015 F type. Light from the laser diode array is directed toward the scene (not shown) .
  • the system controller 15 selects the mode of the electronic switch 16 which allows the diode array 17 to be operated in pulsed mode (position a), continuous mode (position b) and turn off completely (position c). The controller 15 also selects on of three frame memory buffers in the frame store 14 correspondi to images obtained in the three operating modes of the laser diode array.
  • the three outputs from the frame store 14 are processed by digital logic circuitry 18 to produce data representing range information about the scene. This is converted to an analogue signal by a digital to analog converter 19 the output of which i combined by a circuit 20 with video sync information form the sync processor 13. The resulting signal is displayed on a video monitor 21.
  • the image intensifier 9 has a driving voltage which ranges from O V to -60 V and back to 0 V in 30 nSec.
  • the microchannel plate is provided with -850 V (MCP out to MCP in) and the phosphor screen accelerating voltage is 5 V (Screen to MCP out).
  • Receiving lens optics 8 consist of a manually adjusted focus len and a galvanmeter controlled aperture.
  • the filter is a Kodak Wratten filter #87.
  • FIG 8 shows the relevant timing details of the system's hardware.
  • Timing signals (23), (24) and (25) show the select signals for operating the mode switch and governing the frame buffer memory selection in the frame store 14. These are shown in relation to the odd and even fields of the interlaced video signal 22 from the video camera 10.
  • the times when a control signal is asserted is the "active" time and is indicated by reference 26.
  • signal 23 selects the pulsed mode of the laser array.
  • signal 24 When signal 24 is active, it selects the continuous mode of the laser array, while signal 25 being active selects the background mode, during which time the laser array i idle.
  • the laser array is also idle when none of the selections is active (time intervals 27).
  • the active time 26 for a select signal is two video field time in length or 20 mSec.
  • the images are captured during the odd field of the interlaced video represented by the low state of signal 22.
  • Reference 27 represents the recovery time between modes. This allows the phosphor of the image intensifier to return to a neutral state prior to the next selection.
  • the recovery time is also two field times. These timing values are adjusted according to the persistence characteristics of the imaging system.
  • Figure 8 also shows the timing of the waveforms that drive the laser diode during pulsed mode, and drive the image intensifier.
  • the length 28 of the driving pulse is of the order of 30 nSec.
  • the off time 29 may be varied between 30 nSec and greater than 100 nSec.
  • the image intensifier 9 has the same pulse duration and duty cycle as the laser array.
  • a time delay 32 is adjustab over the range + or - 15 nSec. This is to compensate for circui delays and the longitudinal displacement between the laser arra and the image intensifier. This delay is set once, after the system is constructed and is not thereafter adjusted unless recalibration is required.
  • Figure 9 shows approximate graphs of the laser optical output 33 and the image intensifier sensitivity 34. These vary from ideal square waves because of the limited response times of the driver circuitry. The effects of these imperfections on the final rang readings are readily calibrated out of the system.
  • Images obtained from three modes of operation of a pulsed illuminator, gated receiver imaging system are combined through the use of the special hardware to produce a representation of range data for the viewed scene.
  • the system captures a complete range image of the viewed scene using just three images, one fro each mode.
  • the step which measures the background image may be eliminated, particularly when background light levels are low.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

Un générateur d'impulsions (11) envoie des signaux de déclenchement cadencés à un circuit d'attaque d'amplificateur image (12) qui commande la porte de l'amplificateur image (9). Le générateur d'impulsions déclenche également les circuits de commande et un réseau de diodes (7) pour qu'ils émettent de la lumière en direction d'un champ de télémétrie. La lumière réfléchie depuis le champ de télémétrie pénètre dans le système d'imagerie en traversant un filtre (7) et une lentille (8), focalisant ainsi la lumière filtrée sur l'amplificateur (9) sur laquelle est pointée une caméra vidéo (10). La sortie de la caméra vidéo (10) est connectée à une mémoire de bloc image (14) et à un processeur de synchronisation (13). Le contrôleur (15) du système règle un commutateur (16), qui permet au réseau de diodes d'être exploité en mode pulsé (a), en mode continu (b), et en mode d'arrêt. Les trois sorties provenant de la mémoire (14) sont traitées par les circuits (18) pour produire des données représentant des informations de télémétrie rélatives au champ. Ces informations, qui passent ensuite à travers le convertisseur analogique (19), sont combinées avec des informations de synchronisation vidéo provenant du processeur de synchronisation (13) et le signal qui en résulte est affiché sur un moniteur vidéo (21).
PCT/AU1989/000263 1988-06-20 1989-06-20 Dispositif de telemetrie WO1989012837A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPI887688 1988-06-20
AUPI8876 1988-06-20

Publications (1)

Publication Number Publication Date
WO1989012837A1 true WO1989012837A1 (fr) 1989-12-28

Family

ID=3773167

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1989/000263 WO1989012837A1 (fr) 1988-06-20 1989-06-20 Dispositif de telemetrie

Country Status (3)

Country Link
EP (1) EP0424409A4 (fr)
JP (1) JPH03505123A (fr)
WO (1) WO1989012837A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0396867A2 (fr) * 1989-05-12 1990-11-14 DORNIER GmbH Procédé de navigation
EP0396865A3 (fr) * 1989-05-12 1991-02-27 DORNIER GmbH Radar optique
EP0835460A2 (fr) * 1995-06-22 1998-04-15 3DV Systems Ltd. Camera perfectionnee a telemetrie optique
US6445884B1 (en) 1995-06-22 2002-09-03 3Dv Systems, Ltd. Camera with through-the-lens lighting
WO2005052633A1 (fr) * 2003-10-29 2005-06-09 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Capteur de distance et procédé de détection de la distance

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3897150A (en) * 1972-04-03 1975-07-29 Hughes Aircraft Co Scanned laser imaging and ranging system
US4190362A (en) * 1977-05-04 1980-02-26 Societe Anonyme De Telecommunications Laser telemeter
GB2125649A (en) * 1982-08-18 1984-03-07 Eastman Kodak Co Improvements in or relating to rangefinders
US4644149A (en) * 1983-04-18 1987-02-17 Canon Kabushiki Kaisha Photoelectric transducer element
US4812035A (en) * 1986-11-03 1989-03-14 Raytheon Company AM-FM laser radar

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4298280A (en) * 1979-09-25 1981-11-03 Massachusetts Institute Of Technology Infrared radar system
US4501961A (en) * 1982-09-01 1985-02-26 Honeywell Inc. Vision illumination system for range finder
US4678323A (en) * 1984-07-20 1987-07-07 Canon Kabushiki Kaisha Distance measuring devices and light integrators therefor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3897150A (en) * 1972-04-03 1975-07-29 Hughes Aircraft Co Scanned laser imaging and ranging system
US4190362A (en) * 1977-05-04 1980-02-26 Societe Anonyme De Telecommunications Laser telemeter
GB2125649A (en) * 1982-08-18 1984-03-07 Eastman Kodak Co Improvements in or relating to rangefinders
US4644149A (en) * 1983-04-18 1987-02-17 Canon Kabushiki Kaisha Photoelectric transducer element
US4812035A (en) * 1986-11-03 1989-03-14 Raytheon Company AM-FM laser radar

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0424409A4 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0396867A2 (fr) * 1989-05-12 1990-11-14 DORNIER GmbH Procédé de navigation
EP0396865A3 (fr) * 1989-05-12 1991-02-27 DORNIER GmbH Radar optique
EP0396867A3 (fr) * 1989-05-12 1991-08-14 DORNIER GmbH Procédé de navigation
US6445884B1 (en) 1995-06-22 2002-09-03 3Dv Systems, Ltd. Camera with through-the-lens lighting
EP0886790A2 (fr) * 1995-06-22 1998-12-30 3DV Systems Ltd. Camera stereoscopique telecentrique et procede correspondant
EP0835460A4 (fr) * 1995-06-22 1999-01-13 3Dv Systems Ltd Camera perfectionnee a telemetrie optique
EP0835460A2 (fr) * 1995-06-22 1998-04-15 3DV Systems Ltd. Camera perfectionnee a telemetrie optique
US6654556B2 (en) 1995-06-22 2003-11-25 3Dv Systems Ltd. Camera with through-the-lens lighting
EP0886790B1 (fr) * 1995-06-22 2006-03-01 3DV Systems Ltd. Camera stereoscopique telecentrique et procede correspondant
US6993255B2 (en) 1999-02-16 2006-01-31 3Dv Systems, Ltd. Method and apparatus for providing adaptive illumination
US7355648B1 (en) 1999-02-16 2008-04-08 3Dv Systems Ltd. Camera having a through the lens pixel illuminator
WO2005052633A1 (fr) * 2003-10-29 2005-06-09 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Capteur de distance et procédé de détection de la distance
US7186965B2 (en) 2003-10-29 2007-03-06 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandton Forschung E.V Distance sensor and method for detecting a distance

Also Published As

Publication number Publication date
EP0424409A1 (fr) 1991-05-02
EP0424409A4 (en) 1992-01-15
JPH03505123A (ja) 1991-11-07

Similar Documents

Publication Publication Date Title
CA1332978C (fr) Lidar d'imagerie utilisant de la lumiere invisible
EP0462289B1 (fr) Appareil de mesure de coordonnees tridimensionnelles
US6323942B1 (en) CMOS-compatible three-dimensional image sensor IC
CN1099802C (zh) 强度调制辐射场的探测与解调的设备和方法
US4708473A (en) Acquisition of range images
EP0835460B1 (fr) Camera perfectionnee a telemetrie optique
US5048950A (en) Optical radar
US20090091738A1 (en) Surface profile measurement
JP2004538491A (ja) 三次元距離画像を記録するための方法及び装置
EP0431299A2 (fr) Imagerie in-situ à deux longueurs d'ondes solitaires internes
KR20010033549A (ko) 3차원 거리 측정 이미지를 기록하기 위한 방법 및 장치
US4119379A (en) Optical detection and ranging apparatus
Bretthauer et al. An electronic Cranz–Schardin camera
GB2374743A (en) Surface profile measurement
WO1989012837A1 (fr) Dispositif de telemetrie
EP3543742B1 (fr) Système et procédé d'imagerie 3d
AU3831189A (en) Range finding device
Christie et al. Design and development of a multi-detecting two-dimensional ranging sensor
GB2154388A (en) Image processing system
CN100417915C (zh) 无扫描器的成像测距方法及其测距仪
Kotake et al. Performance improvement of real-time 3D imaging ladar based on a modified array receiver
JPH0136082B2 (fr)
EP0777134A1 (fr) Dispositif d'observation d'objets
SU712662A1 (ru) Способ телевизионного автоматического измерени размеров однородных объектов
SU275423A1 (ru) Фотоэлектронное устройство дл измерени толщины гор чего и холодного проката

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1989907048

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1989907048

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1989907048

Country of ref document: EP