US3858223A - Device for photographic monitoring of road intersections controlled by a traffic light - Google Patents

Device for photographic monitoring of road intersections controlled by a traffic light Download PDF

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Publication number
US3858223A
US3858223A US00436036A US43603674A US3858223A US 3858223 A US3858223 A US 3858223A US 00436036 A US00436036 A US 00436036A US 43603674 A US43603674 A US 43603674A US 3858223 A US3858223 A US 3858223A
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multivibrator
signal
sensor
pulse
output
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English (en)
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J Holzapfel
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Robot Foto and Electronic GmbH and Co KG
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Robot Foto and Electronic GmbH and Co KG
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    • GPHYSICS
    • G08SIGNALLING
    • G08GTRAFFIC CONTROL SYSTEMS
    • G08G1/00Traffic control systems for road vehicles
    • G08G1/01Detecting movement of traffic to be counted or controlled
    • G08G1/017Detecting movement of traffic to be counted or controlled identifying vehicles
    • G08G1/0175Detecting movement of traffic to be counted or controlled identifying vehicles by photographing vehicles, e.g. when violating traffic rules

Definitions

  • That vehicle illegally entering the intersection turns right, it activates a second sensor which sends a signal to cause another picture to be taken.
  • a second vehicle illegally entering behind the first will not interrupt the sequence of pictures initiated by the first, but will result in another picture being taken after a predetermined time lapse.
  • This invention relates to a device for photographic monitoring of road intersections at which there is a traffic light, in which device a photographic camera is triggered by a sensor responding to a vehicle entering the intersection during the stop period of the traffic light, and in which device there is also provision for triggering a second camera exposure.
  • a sensor is positioned at a point along the road near the traffic light. This sensor supplies a signal when a vehicle passes over it. If the signal appears during the stop interval of the traffic light, i.e. a vehicle has entered the road intersection during the stop interval contrary to traffic regulations, a photographic camera will be triggered. The field of view of this camera covers the road intersection. Thereby a photograph is made of the traffic violation and also of the license plate of the violating vehicle (German patent 683,658).
  • a second sensor is positioned in the road, and an additional exposure is triggered if said second sensor responds within said delay time.
  • a first monostable multivibrator is connected to be triggered by the first sensor.
  • This monostable multivibrator opens a first gate circuit in a control path for a trigger signal from the second sensor to the camera.
  • the second exposure can be triggered by the first monostable multivibrator returning to its stable state after said predetermined delay time.
  • the second exposure will be made at the end of the delay time in any event and will occur also if the vehicle continues to go straight ahead and only touches the second sensor.
  • the first sensor is an induction loop which controls a detector circuit.
  • the pulse from the detection circuit should have a duration of at least the time required by the whole length of the vehicle to pass over the sensor.
  • a second monostable multivibrator which remains in its metastable state for a shorter interval than the duration of said pulse from the detection circuit is connected to be triggered by the front edge of the detection circuit pulse in order to reduce the pulse width.
  • the output pulses of the second monostable multivibrator trigger said first monostable multivibrator directly or through further intermediate circuits.
  • an initial pulse is produced by the detector circuit. This pulse continues while the entire length of the vehicle passes over the induction loop. This makes sure that one vehicle will not produce a plurality of sensor pulses, for example one for each axle. I This initial pulse is, however, too long for the actua tion of the processing circuit. Therefore a second pulse of shorter duration is derived therefrom by the second monostable multivibrator. This shorter pulse can then be used in a manner whereby the output of the second monostable multivibrator triggers a third monostable multivibrator to produce a pulse signal triggering the first camera exposure. Also, the rear edge of the latter pulse signal is used to trigger said first monostable multivibrator.
  • the signal triggering the second exposure is produced by a fourth monostable multivibrator connected to be triggered by the first monostable multivibrator returning to its stable state.
  • a fifth monostable multivibrator is connected to the output of the fourth monostable multivibrator to be triggered by the rear edge of said exposure triggering signal, remains in its metastable state for an interval substantially equal to the film feed time, and blocks a gate circuit in said control path of said exposure triggering signal;
  • FIG. 2 is a schematic diagram of the circuit used in an embodiment of the invention.
  • FIG. 3 is a more detailed wiring diagram.
  • FIG. 1 shows a road intersection formed by two roads l and 12 intersecting each other at right angles.
  • the road intersection is controlled by a traffic light installation, only one of which is shown.
  • This is light 14 which controls the lane of movement of vehicles from left to right in road 10.
  • the present description only describes the apparatus employed in conjunction with this lane, but it will be'understood that corresponding apparatus is employed in conjunction with the remaining lanes.
  • Pedestrian walks 16 have been marked on the road surface at the road intersection.
  • the road intersection is automatically monitored by aphotographic camera'20, in order to make a conclusive photographic record of all vehicles which enter or cross the roadintersection during the stop interval.
  • the induction loop I is connected to a detector circuit D, which produces a signal when a vehicle passes over the induction loop (FIG. 2).
  • a signal is applied to a control input 26 of a NAND-gate N
  • NAND-gate N When a signal from detector circuit D, is received by NAND-gate N during the stop interval that signal triggers a monostable multivibrator MF, through an inverter N ,5.
  • the monostable multivibrator MF produces a trigger signal to be applied to the camera through a control path 28.
  • the monostable multivibrator MF By returning into its stable state, the monostable multivibrator MF, triggers a monostable multivibrator MF, which changes to its metastable state for a predetermined delay time.
  • the monostable multivibrator MF returns to its stable state it triggers a monostable multivibrator MP through a NAND-gate N -andan inverter N
  • Monostable multivibrator MP also applies a triggering signal to the camera through a control path 30.
  • a first exposure will be triggered by monostable multivibrator MF,, when a vehicle passes the induction loop I, during the stop interval of the traffic lights, and thereafter a second exposure will be triggered by the monostable multivibrator MF, after a delay time deter-- mined by the monostable multivibrator MP
  • A'second sensor in the form of induction loop I is located on the right-turn lane of road 12.
  • Induction loop I is connected to a detector circuit D which produces a signal when a vehicle passes over it. This signal is inverted by the inverter N and is applied to a second input of the NAND-gate N Normally (i.e.
  • the signal is applied by detector circuit D, to one input of NAND-gate N through leads 32, 34, and to one input of another NAND-gate N,, through lead 32 and lead 36.
  • the function of NAND-gate N is explained below.
  • a monostable multivibrator MF comprising two transistors T T, is triggered by the output signal of the detector circuit D applied to the base of transistor T
  • the monostable multivibrator is triggered by the front edge of the output signal from detector circuit D,. It applies a signal through leads 38, 40 and 42 to one input, respectively, of each of the NAND-gates N and N Multivibrator MP produces an output pulse to lead 38 which is relatively short as compared to the duration of the input pulse from detector circuit D,.
  • a signal is applied to an input E when the stop interval of the traffic light 14 commences. This signal is applied to the base of a transistor T which operates as an inverter. Transistor T controls a transistor T operating as an electronic switch. When the switch is opened, i.e. the transistor T is nonconducting, a capacitor C is charged through an adjustable resistor P,. The voltage across capacitor C controls a Schmitt trigger comprising transistors T T and T Thereby a predetermined time interval can be selected, during which a vehicle passing over the induction loop I will not trigger an exposure.
  • the output signal of the Schmitt trigger is applied through an inverter N the control line 26 and lines 44 and 46 to one input of each of the NAND-gates N and N
  • the output of the NAND-gate N is applied through the inverter N to the input of the monostable multivibrator MP
  • the monostable multivibrator MF supplies a triggering signal for triggering the first exposure of the camera
  • This triggering signal applied to line 28 triggers a monostable multivibrator MP through NAND-gates N and N (the function of which will be described below) and through lead 48.
  • Monostable multivibrator MP produces a signal through lead 50 to an amplifier (not shown) which energize the triggering solenoid of the camera 20.
  • a monostable multivibrator MP is triggered through lead 52.
  • the monostable multivibrator MP remains in its metastable state during an interval equal to the desired delay time between the first and the second exposure.
  • the monostable multivibrator MP is triggered by the rear edge of the output signal 48 by the rear edge of the applied signal, thus by the transition from L to O.
  • This output of the monostable multivibrator MF, (which is in the state 0 when the monostable multivibrator is in its metastable state) and the respective outputs of the monostable multivibrators MF MB and MP are connected to an NAND-gate N through leads 58, 60, 62 and 64, respectively.
  • NAND-gate N is L, if anyone of the monostable multivibrators MP MP MP or MF, is in its metastable, i.e. triggered, state.
  • This output L is made on O by an inverter N and applied through line 66 to a further input of the NAND-gate N Therefore the NAND-gate N is rendered non-conductive during the passage of the signal through the monostable multivibrators MF,, MP MP and MP
  • the output L of gate N is directly applied through line 66 to a further input of the NAND-gate N This results in the gate circuit comprising NAND-gate N 14 and the inverter N being rendered conductive if all leads are on positive potential.
  • Monostable multivibrator MP supplies a triggering signal to the monostable multivibrator MF through line 30, NAND-gates N and N and lead 48.
  • Monostable multivibrator MF supplies a pulse to the triggering solenoid of the camera through lead 50.
  • a monostable multivibrator MP When the monostable multivibrator MP returns to its stable state, a monostable multivibrator MP, is triggered through lead 54. Monostable multivibrator MP, is connected to remain in its unstable state during an interval substantially equal to the film feed time. Multivibrator MF, is to make sure'that no further pulse can be supplied to the triggering solenoid of the camera while the film is being advanced.
  • the monostable multivibrator MF renders NAND-gate N nonconductive to signals from MP MP or MP and thereby prevents the triggering of the monostable multivibrator MP
  • the output of the monostable multivibrator MP is in the state 0, when the monostable multivibrator MP, is in its metastable state, lead 56 extending from this output.
  • the output of NAND- gate N is L, regardless of which signal is applied to the other input of the NAND-gate N
  • the monostable multivibrator MP is, however, triggered through lead its metastable state for a hold time of, for example, 1.3 seconds.
  • the monostable multivibrator MF is triggered through lead 72 by the monostable multivibrator MP returning into its stable state.
  • the monostable multivibrator MF generates a triggering signal on a lead 74, which also triggers the monostable multivibrator MP through gates N and N and lead 48. This results in a pulse being applied to the triggering solenoid of the camera through lead 50.
  • Signal 0 appears on lead 74 when the monostable multivibrator MF is in its metastable state.
  • signal L is applied to lead 74.
  • there is also L-signal on lead 28 from monostable multivibratorMF, and on lead 30 from monostable multivibrator MF Thus 0 appears at the output of NAND-gate N and consequently L appears at the output of NAND-gate N If one of the monostable multivibrators MP MF, or MF, is triggered and changes over into its metastable state, the signal on the respective lead 74, 28 or 30 becomes 0.
  • the output 76 of the monostable multivibrator MP is applied to a monostable multivibrator MP, to trigger the monostable multivibrator MP when the monostable multivibrator MP returns into its stable state.
  • the monostable multivibrator MP has the same function as the monostable multivibrator MP It is to prevent triggering of the camera during the film feed operation.
  • the monostable multivibrator MF remains in its metastable state during a hold time substantially equal is in the state 0, when the monostable multivibrator MP is in its metastable-state, is connected to a NAND- gate N through lead 78.
  • Lead 56 from the monostable multivibrator ME also is connected to an input of gate Nzz- The output from NAN D-gate N is 0, when neither of the monostable multivibrators MF, and MP, is
  • the device of the invention makes it possible to conclusively record traffic violations at road intersections controlled by traffic lights even under unfavorthe NAND-gate N llf one of the monostable-multivibrators MP or MP is triggered, the NAND-gate N will be rendered non-conductive.
  • the outputs from the monostablemultivibrators MF MF and MB, which supply the signal 0, when the respective monostable multivibrator is in its metastable state, are applied respectively to the three inputs of a NAND-gate N
  • the output of this NAND-gate becomes L, when one of the three monostable multivibrators MF MF or MP is triggered.
  • This output L is then converted into an O-signal bythe inverter N this O-signal being applied to the input leads 82, 84 of the NAND-gates N and N respectively and rendering these NAND- gates non-conductive,
  • all further input signal triggers a monostable multivibrator MF comprising transistors T, and T Thereby a short pulse, as
  • the monostable multivibrator MP which is triggered by the rear edge of its input signal, will be triggered, when' either the monostable multivibrator MP returns into its stable state and brings one input of NAND-gate N into the state 0, or when an output pulse from the monostable multivibrator MF appears and through the inverter N brings the other input of the NAND-gate N into the state 0. In. both cases a triggering signal is applied to line 30 by the monostable multivibrator.
  • the circuit comprising the monostable multivibrator MP NAND-gate N inverter N and monostable multivibrator MP operates in a corresponding manner.
  • a vehicle passes over the sensor comprising induction loop 1 during the delay time between the first and thesecond exposure (monostable multivibrator MF being triggered) or during the delay time by I able conditions such as with a plurality of vehicles entering the road intersection in rapid succession and/or with vehicles turning off.
  • An improvement for an apparatus for photographically monitoring an intersection of'two roads, at which there is a traffic light, by making photographs of vehicles entering the intersection against the stop signal of the traffic light said apparatus including a first sensor positioned along one of the roads to produce a signal when a vehicle passes the first sensor, afirst device to produce a first camera-actuating pulse in response to said signal for taking an initial photograph,;and a second device to produce a second-camera-actuating pulse a predetermined delay time afterv said initial photo graph for taking a second, photograph, said improvement comprising: g
  • a second sensor positioned along the other of the two roads to produce a signal when a vehicle passes the second sensor; and I means connected to saidsecond sensor and to said apparatus for producing a camera-actuating pulse when a signal from the second sensor occurs within said given period of time after the signal from the first sensor.
  • said first sensor comprises an induction loop; including a detection circuit connected to thefirst sensor for producing a detection pulse in response to the signal from the first sensor which detection pulse has a duration of at least the time required by the vehicle to pass the first sensor; and
  • said first device comprises a second monostable multivibrator which remains in its metastable'state for a shorter period of time than the duration of said detection pulse, means connecting said second multivibrator to said detection circuit to trigger the second multivibrator from its stable state to its metastable state by the initiation of said detection pulse, and means connecting said second multivibrator to the first multivibrator to normally triggerthe latter when the second multivibrator returns to its stable state.
  • said first device includes a third monostable multivibrator having an input andan output, said second multivibrator being connected to said input whereupon the third multivibrator produces a pulse signal at its output in response to a signal at its input, means connecting said output of said third multivibrator t the first multivibrator to trigger the latter by the rear edge of said output pulse signal, and means connected to said output of said third multivibrator to use said output pulse signal to form said first cameraactuating pulse.
  • said means defining said control paths for said camera-actuating pulses includes second gate means;
  • said second device includes a fourth monostable multivibrator having an input and an output, means connecting the input of the fourth multivibrator to the first multivibrator to trigger the former by the latter returning to its stable state to thereby produce a signal at the output of the fourth multivibrator for forming said second cameraactuating pulse, a fifth monostable multivibrator having a metastable state duration substantially equal to the film feed time, means connecting said fifth multivibrator to the fourth multivibrator to be triggered by the rear edge of said output signal of the fourth multivibrator, and means connecting the second gate means to said fifth multivibrator to close said second gate means when the fifth multivibrator is in its metastable state to thereby prevent a camera-actuating pulse from being formed during the film feed time following said production of said signal at the output of the fourth multivibrator.
  • fourth gate means connected to said first device which is open and permits a signal to pass therethrough to produce a detection pulse when said third gate means is blocking
  • a seventh monostable multivibrator connected to said sixth multivibrator for producing a cameraactuating pulse in response to said delayed passed signal.

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  • General Physics & Mathematics (AREA)
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US00436036A 1973-02-14 1974-01-24 Device for photographic monitoring of road intersections controlled by a traffic light Expired - Lifetime US3858223A (en)

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Application Number Priority Date Filing Date Title
DE2307217A DE2307217C3 (de) 1973-02-14 1973-02-14 Vorrichtung zur photographischen Überwachung von ampelgesteuerten Kreuzungen

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US (1) US3858223A (fr)
JP (1) JPS5415200B2 (fr)
DD (1) DD109461A5 (fr)
FR (1) FR2217751A1 (fr)
NL (1) NL158307B (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4353054A (en) * 1977-03-02 1982-10-05 King Lawrence J Stop sign watcher, a device for monitoring vehicles at full stop sign intersections
DE3532527A1 (de) * 1985-09-12 1987-03-19 Robot Foto Electr Kg Vorrichtung zur photographischen ueberwachung von kreuzungen
US5343237A (en) * 1990-10-08 1994-08-30 Matsushita Electric Industrial Co., Ltd. System for detecting and warning an illegally parked vehicle
US5508774A (en) * 1994-07-14 1996-04-16 Eastman Kodak Company Automatic image capture station
US5912822A (en) * 1994-06-01 1999-06-15 American Traffic Systems, Inc. Frequency domain processing of Doppler signals in a traffic monitoring system
US5929787A (en) * 1996-11-27 1999-07-27 Mee; Gary L. Vibration actuated traffic light control system
US5935190A (en) * 1994-06-01 1999-08-10 American Traffic Systems, Inc. Traffic monitoring system
US5948038A (en) * 1996-07-31 1999-09-07 American Traffic Systems, Inc. Traffic violation processing system
US6111523A (en) * 1995-11-20 2000-08-29 American Traffic Systems, Inc. Method and apparatus for photographing traffic in an intersection
US6188329B1 (en) 1998-11-23 2001-02-13 Nestor, Inc. Integrated traffic light violation citation generation and court date scheduling system
US20020135471A1 (en) * 2000-04-21 2002-09-26 Bbnt Solutions Llc Video-monitoring safety systems and methods
US6754663B1 (en) 1998-11-23 2004-06-22 Nestor, Inc. Video-file based citation generation system for traffic light violations
US6760061B1 (en) 1997-04-14 2004-07-06 Nestor Traffic Systems, Inc. Traffic sensor
US20050046597A1 (en) * 2003-08-18 2005-03-03 Hutchison Michael C. Traffic light signal system using radar-based target detection and tracking

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2549263A1 (fr) * 1983-07-11 1985-01-18 Malvolti Amedeo Appareil electronique permettant d'enregistrer le passage et la vitesse d'un vehicule automobile

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2871088A (en) * 1952-10-18 1959-01-27 Abell Frank Method of obtaining evidence of traffic signal violations
US3060434A (en) * 1958-03-04 1962-10-23 Agfa Ag Method and apparatus for traffic surveillance

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2871088A (en) * 1952-10-18 1959-01-27 Abell Frank Method of obtaining evidence of traffic signal violations
US3060434A (en) * 1958-03-04 1962-10-23 Agfa Ag Method and apparatus for traffic surveillance

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4353054A (en) * 1977-03-02 1982-10-05 King Lawrence J Stop sign watcher, a device for monitoring vehicles at full stop sign intersections
DE3532527A1 (de) * 1985-09-12 1987-03-19 Robot Foto Electr Kg Vorrichtung zur photographischen ueberwachung von kreuzungen
WO1987001847A1 (fr) * 1985-09-12 1987-03-26 Robot Foto Und Electronic Gmbh & Co. Kg Dispositif de surveillance photographique de carrefours
US4884072A (en) * 1985-09-12 1989-11-28 Heinrich Horsch Device for photographic monitoring of cross-roads
US5343237A (en) * 1990-10-08 1994-08-30 Matsushita Electric Industrial Co., Ltd. System for detecting and warning an illegally parked vehicle
US5935190A (en) * 1994-06-01 1999-08-10 American Traffic Systems, Inc. Traffic monitoring system
US5912822A (en) * 1994-06-01 1999-06-15 American Traffic Systems, Inc. Frequency domain processing of Doppler signals in a traffic monitoring system
US5508774A (en) * 1994-07-14 1996-04-16 Eastman Kodak Company Automatic image capture station
US6111523A (en) * 1995-11-20 2000-08-29 American Traffic Systems, Inc. Method and apparatus for photographing traffic in an intersection
US5948038A (en) * 1996-07-31 1999-09-07 American Traffic Systems, Inc. Traffic violation processing system
US5929787A (en) * 1996-11-27 1999-07-27 Mee; Gary L. Vibration actuated traffic light control system
US6760061B1 (en) 1997-04-14 2004-07-06 Nestor Traffic Systems, Inc. Traffic sensor
US6281808B1 (en) 1998-11-23 2001-08-28 Nestor, Inc. Traffic light collision avoidance system
US6573929B1 (en) 1998-11-23 2003-06-03 Nestor, Inc. Traffic light violation prediction and recording system
US6647361B1 (en) 1998-11-23 2003-11-11 Nestor, Inc. Non-violation event filtering for a traffic light violation detection system
US20040054513A1 (en) * 1998-11-23 2004-03-18 Nestor, Inc. Traffic violation detection at an intersection employing a virtual violation line
US6754663B1 (en) 1998-11-23 2004-06-22 Nestor, Inc. Video-file based citation generation system for traffic light violations
US6188329B1 (en) 1998-11-23 2001-02-13 Nestor, Inc. Integrated traffic light violation citation generation and court date scheduling system
US6950789B2 (en) 1998-11-23 2005-09-27 Nestor, Inc. Traffic violation detection at an intersection employing a virtual violation line
US20020135471A1 (en) * 2000-04-21 2002-09-26 Bbnt Solutions Llc Video-monitoring safety systems and methods
US20050046597A1 (en) * 2003-08-18 2005-03-03 Hutchison Michael C. Traffic light signal system using radar-based target detection and tracking
US7821422B2 (en) 2003-08-18 2010-10-26 Light Vision Systems, Inc. Traffic light signal system using radar-based target detection and tracking

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Publication number Publication date
FR2217751A1 (fr) 1974-09-06
JPS49119599A (fr) 1974-11-15
DD109461A5 (fr) 1974-11-05
NL7401944A (fr) 1974-08-16
JPS5415200B2 (fr) 1979-06-13
NL158307B (nl) 1978-10-16

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