JP2011150551A - Vehicle monitoring system - Google Patents

Vehicle monitoring system Download PDF

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JP2011150551A
JP2011150551A JP2010011458A JP2010011458A JP2011150551A JP 2011150551 A JP2011150551 A JP 2011150551A JP 2010011458 A JP2010011458 A JP 2010011458A JP 2010011458 A JP2010011458 A JP 2010011458A JP 2011150551 A JP2011150551 A JP 2011150551A
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vehicle
license plate
monitoring system
vehicle monitoring
infrared projector
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JP5429988B2 (en
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Takehiko Uchiumi
武彦 内海
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Panasonic Electric Works Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle monitoring system for clearly imaging all license plates by discriminating the type of the license plate based on the luminance value of the license plate measured by a luminance sensor, and controlling the output of an infrared projector with emission strength which is optimal to the imaging of the discriminated license plate. <P>SOLUTION: When a laser sensor 13 detects the passage of a vehicle 20, a luminance sensor 14 measures a luminance value B of a license plate 22, and when the luminance value B is lower than a predetermined threshold S, an infrared projector 15 is made to emit the rays of light with relatively high emission strength BH, and when the luminance value B is higher than the threshold S, the infrared projector 15 is made to emit the rays of light with relatively low emission strength BL, and the license plate 22 is imaged by a vehicle monitoring camera 16. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、路上等において走行する車両のナンバープレートを監視カメラで撮像する車両監視システムに関する。   The present invention relates to a vehicle monitoring system that images a license plate of a vehicle traveling on a road or the like with a monitoring camera.

路上等において車両のナンバープレートを監視カメラで撮像するようにした車両監視システムが知られている。従来、このような車両監視システムとしては、車検知センサが車両を検知すると、カメラで車両を撮像してナンバープレートの輝度値を計算し、この輝度値に基づいてカメラの絞り値を調整して再度撮像するようにして、種類の異なるナンバープレートでも、１台のカメラで鮮明に撮像できるようにしたナンバープレート自動認識方法及びその装置が提案されている（例えば、特許文献１参照）。また、通常は消灯状態にある照明装置を、カメラの視野より遠方で焦電センサが車両を検知した場合にのみ点灯して、消費電力が少なく、且つ長寿命とした車番認識装置が開示されている（例えば、特許文献２参照）。
また、屋外の所定場所を通過する車両のナンバープレートをカメラで撮像し、該カメラから得られた画像信号を処理して車両ナンバーを読み取る場合において、昼間と夜間とで画像信号を得る際のγを制御するようにし、あらかじめコンピュータ側で画像を補正しておくものも提案されている（特許文献３参照）。 2. Description of the Related Art A vehicle monitoring system is known in which a license plate of a vehicle is imaged with a monitoring camera on the road or the like. Conventionally, as such a vehicle monitoring system, when a vehicle detection sensor detects a vehicle, the vehicle is imaged by a camera, a brightness value of a license plate is calculated, and an aperture value of the camera is adjusted based on the brightness value. There has been proposed an automatic license plate recognition method and apparatus for imaging again, so that different types of license plates can be clearly imaged with one camera (see, for example, Patent Document 1). In addition, a vehicle number recognition device is disclosed in which a lighting device that is normally off is turned on only when the pyroelectric sensor detects the vehicle at a distance from the field of view of the camera, and consumes less power and has a longer life. (For example, refer to Patent Document 2).
In addition, when a license plate of a vehicle passing through a predetermined outdoor location is imaged with a camera, and an image signal obtained from the camera is processed to read a vehicle number, γ when obtaining an image signal between daytime and nighttime It has been proposed to correct the image in advance on the computer side (see Patent Document 3).

このような車両監視カメラを有する車両監視システムは、昼夜を問わず使用されるため、夜間は赤外線を発光する発光ダイオード（以下、「ＬＥＤ」と略記する）を光源とした赤外線投光器で被写体（車両）を照明している。筺体に取り付けられたＬＥＤを有する赤外線投光器では、ナンバープレートを鮮明に撮像可能とすることが重要であるが、ナンバープレートには、自発光型ナンバープレートと、非発光型ナンバープレートとが混在する。このため、一方のナンバープレートの撮像に最適な発光強度で発光するように赤外線投光器の出力を設定すると、他方のナンバープレートを鮮明に撮像できなくなる虞がある。   Since the vehicle monitoring system having such a vehicle monitoring camera is used day and night, the subject (vehicle) is an infrared projector using a light emitting diode (hereinafter abbreviated as “LED”) that emits infrared light at night. ). In an infrared projector having an LED attached to a housing, it is important that the license plate can be clearly imaged. For this reason, if the output of the infrared projector is set so as to emit light with the optimum light emission intensity for imaging one license plate, the other license plate may not be clearly imaged.

例えば、日本で使用される多くのナンバープレートは、非発光型ナンバープレートであるので、この非発光型ナンバープレートの撮像に最適な発光強度に設定すると、自発光型ナンバープレートを撮像すると、輝度が高くなって画像にハレーションが発生する。逆に、自発光型ナンバープレートの撮像に最適な発光強度に設定すると、非発光型ナンバープレートへの照射光量が不足することになり、鮮明な画像が得られなくなる。   For example, many license plates used in Japan are non-emission type license plates, so if you set the light emission intensity to be optimal for imaging non-emission type license plates, the brightness will be higher when imaging self-emission type license plates. It becomes high and halation occurs in the image. On the other hand, if the light emission intensity is set to be optimal for imaging the self-luminous license plate, the amount of light applied to the non-light-emitting license plate is insufficient, and a clear image cannot be obtained.

特開平０８−２８７３９０号公報Japanese Patent Laid-Open No. 08-287390 特開平１０−２６１１９０号公報Japanese Patent Laid-Open No. 10-261190 特開２００２−３００４３７号公報JP 2002-300437 A

本発明は、前記実情に鑑みてなされたもので、輝度センサで測定した車両のナンバープレートの輝度値に基づいてナンバープレートの種類を判別し、判別されたナンバープレートの撮像に最適な発光強度で赤外線投光器の出力を制御して、すべてのナンバープレートを鮮明に撮像可能とした車両監視システムを提供することを目的とする。   The present invention has been made in view of the above circumstances, and determines the type of the license plate based on the luminance value of the license plate of the vehicle measured by the luminance sensor, with the optimum emission intensity for imaging of the determined license plate. An object of the present invention is to provide a vehicle monitoring system that can control the output of an infrared projector to clearly image all license plates.

本発明は、車両を撮像する車両監視カメラと、前記車両を照明する赤外線投光器と、を有する車両監視システムであって、路面上を走行する前記車両の通過を検知するレーザーセンサと、前記車両のナンバープレートの輝度値を測定する輝度センサと、前記赤外線投光器の発光強度を制御する制御部と、を備え、前記制御部は、前記輝度センサによって測定された前記ナンバープレートの前記輝度値が、予め決められた閾値よりも低い場合、相対的に高い発光強度である第１の発光強度で前記赤外線投光器から発光させ、前記輝度センサによって測定された前記ナンバープレートの前記輝度値が、予め決められた前記閾値よりも高い場合、前記第１の発光強度より相対的に低い第２の発光強度で前記赤外線投光器から発光させる。   The present invention is a vehicle monitoring system including a vehicle monitoring camera that images a vehicle and an infrared projector that illuminates the vehicle, a laser sensor that detects the passage of the vehicle traveling on a road surface, and the vehicle A brightness sensor that measures the brightness value of the license plate; and a control unit that controls the light emission intensity of the infrared projector, wherein the control unit has the brightness value of the license plate measured by the brightness sensor in advance. When the threshold value is lower than the predetermined threshold value, the infrared light projector emits light at a first light emission intensity that is a relatively high light emission intensity, and the brightness value of the license plate measured by the brightness sensor is predetermined. When it is higher than the threshold value, the infrared light projector emits light with a second light emission intensity relatively lower than the first light emission intensity.

この構成により、赤外線投光器は、種類の異なるナンバープレートに対して常に撮像に最適な強度で発光し、どの種類のナンバープレートでも鮮明に撮像することが可能となる。   With this configuration, the infrared projector always emits light with the optimum intensity for imaging with respect to different types of license plates, and it is possible to clearly capture images of any type of license plates.

また、本発明は、上記の車両監視システムにおいて、前記閾値は、前記輝度センサによって測定される自発光型ナンバープレートの輝度値と、非発光型ナンバープレートの輝度値とを判別可能であるものを含む。   In the vehicle monitoring system according to the present invention, the threshold value can discriminate between a luminance value of a self-luminous license plate measured by the luminance sensor and a luminance value of a non-luminous license plate. Including.

この構成により、輝度センサによって測定されたナンバープレートの輝度値を閾値と比較することによって、ナンバープレートの種類を判別することができ、判別されたナンバープレートの撮像に最適な強度で赤外線投光器を発光させて、すべてのナンバープレートを鮮明に撮像することができる。   With this configuration, the license plate brightness can be determined by comparing the brightness value of the license plate measured by the brightness sensor with a threshold value, and the infrared projector emits light with the optimum intensity for imaging the determined license plate. Thus, all the license plates can be imaged clearly.

更に、本発明は、上記の車両監視システムにおいて、前記赤外線投光器は、一方の垂直面に開口部を有する方形箱形状の筐体と、前記筐体の開口部近傍に設けられ、複数の赤外線ＬＥＤを平面状に配列したＬＥＤ基板から構成される面状発光体と、を備えるものを含む。   Furthermore, the present invention provides the vehicle monitoring system, wherein the infrared projector is provided in a rectangular box-shaped housing having an opening on one vertical surface, and in the vicinity of the opening of the housing, and includes a plurality of infrared LEDs. And a planar light emitter composed of an LED substrate arranged in a plane.

この構成により、面状発光体をコンパクトに構成することができるとともに、監視カメラによって昼夜を問わず、且つ、運転者に気づかれることなく車両を撮像することができる。   With this configuration, the planar light emitter can be configured in a compact manner, and the vehicle can be imaged by the surveillance camera regardless of day and night and without being noticed by the driver.

本発明によれば、輝度センサで測定した車両のナンバープレートの輝度値に基づいてナンバープレートの種類を判別し、判別された種類のナンバープレートの撮像に最適な発光強度で赤外線投光器の出力を制御するため、すべての種類のナンバープレートを鮮明に撮像可能な車両監視システムを提供することができる。   According to the present invention, the type of the license plate is determined based on the luminance value of the vehicle license plate measured by the luminance sensor, and the output of the infrared projector is controlled with the optimum light emission intensity for imaging the determined type of license plate. Therefore, it is possible to provide a vehicle monitoring system that can clearly image all types of license plates.

本発明の実施の形態に係る車両監視システムの構成を示す図であり、（ａ）は車両監視システムの平面図、（ｂ）はこの平面図の側面図It is a figure which shows the structure of the vehicle monitoring system which concerns on embodiment of this invention, (a) is a top view of a vehicle monitoring system, (b) is a side view of this top view 本発明の実施の形態に係る車両監視システムの概略構成を示すブロック図The block diagram which shows schematic structure of the vehicle monitoring system which concerns on embodiment of this invention 本発明の実施の形態に係る赤外線投光器の外観を示す斜視図The perspective view which shows the external appearance of the infrared projector which concerns on embodiment of this invention 本発明の実施の形態に係る車両監視システムの制御手順を説明するためのフローチャートThe flowchart for demonstrating the control procedure of the vehicle monitoring system which concerns on embodiment of this invention. 本発明の実施の形態に係る車両監視システムの動作を説明するためのタイムチャートTime chart for explaining the operation of the vehicle monitoring system according to the embodiment of the present invention

以下、本発明の実施形態に係る車両監視システムについて、図面を参照しつつ詳細に説明する。
図１は本発明の実施の形態に係る車両監視システムの構成を示す図であり、（ａ）は車両監視システムの平面図、（ｂ）はこの平面図の側面図である。同図に示すように、本実施形態の車両監視システム１０は、道路１１上を走行する車両２０の通過を検知するレーザーセンサ１３と、このレーザーセンサ１３より車両２０の進行方向前方に配置された輝度センサ１４、赤外線投光器１５、車両監視カメラ１６、及び制御部１７とから構成されている。 Hereinafter, a vehicle monitoring system according to an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a vehicle monitoring system according to an embodiment of the present invention. (A) is a plan view of the vehicle monitoring system, and (b) is a side view of the plan view. As shown in the figure, the vehicle monitoring system 10 of the present embodiment is arranged in front of the laser sensor 13 that detects the passage of the vehicle 20 traveling on the road 11 and the traveling direction of the vehicle 20 from the laser sensor 13. It comprises a luminance sensor 14, an infrared projector 15, a vehicle monitoring camera 16, and a control unit 17.

レーザーセンサ１３は、道路１１を横断する両側に配設された一対の支柱１２内に、それぞれ収容されたレーザー照射部１３ａとレーザー受光部１３ｂとからなり、レーザー照射部１３ａから照射されるレーザーＬが、レーザー受光部１３ｂで受光される。車両２０がレーザー照射部１３ａから照射されるレーザーＬを遮ると、レーザーＬがレーザー受光部１３ｂで受光できなくなることで、車両２０の通過を検知する。   The laser sensor 13 includes a laser irradiation unit 13a and a laser light receiving unit 13b respectively accommodated in a pair of support columns 12 arranged on both sides crossing the road 11, and the laser L irradiated from the laser irradiation unit 13a. Is received by the laser receiving unit 13b. When the vehicle 20 blocks the laser L emitted from the laser irradiation unit 13a, the laser L cannot be received by the laser light receiving unit 13b, thereby detecting the passage of the vehicle 20.

輝度センサ１４、赤外線投光器１５、及び車両監視カメラ１６は、レーザーセンサ１３より車両２０の進行方向前方に配置されて、その前面側をレーザーセンサ１３方向、即ち走行する車両２０の前面２１、更に詳細には、車両２０のナンバープレート２２に向けて設置されている。   The brightness sensor 14, the infrared projector 15, and the vehicle monitoring camera 16 are disposed in front of the laser sensor 13 in the traveling direction of the vehicle 20, and the front side thereof is in the direction of the laser sensor 13, that is, the front surface 21 of the traveling vehicle 20. Is installed toward the license plate 22 of the vehicle 20.

これにより、輝度センサ１４は、ナンバープレート２２の輝度値を測定し、赤外線投光器１５は、車両２０、特にナンバープレート２２の近傍を照明し、車両監視カメラ１６は、赤外線投光器１５で照明されたナンバープレート２２を撮像可能である。また、制御部１７は、不図示のマイクロコンピュータを含む電気回路で構成される。   Thereby, the brightness sensor 14 measures the brightness value of the license plate 22, the infrared projector 15 illuminates the vehicle 20, particularly the vicinity of the license plate 22, and the vehicle monitoring camera 16 is the number illuminated by the infrared projector 15. The plate 22 can be imaged. Moreover, the control part 17 is comprised with the electric circuit containing the microcomputer not shown.

図２は、本発明の実施の形態に係る車両監視システムの概略構成を示すブロック図である。図２に示すように、本実施形態の車両監視システム１０は、レーザーセンサ１３、輝度センサ１４、赤外線投光器１５、車両監視カメラ１６、制御部１７、及び電源部１８を有して構成されている。   FIG. 2 is a block diagram showing a schematic configuration of the vehicle monitoring system according to the embodiment of the present invention. As shown in FIG. 2, the vehicle monitoring system 10 of the present embodiment includes a laser sensor 13, a luminance sensor 14, an infrared projector 15, a vehicle monitoring camera 16, a control unit 17, and a power supply unit 18. .

赤外線投光器１５は、図３に示すように、一方の垂直面に開口部２６を有する略方形箱形状の筐体２５の内部に、面状発光体２７が収容された構成である。面状発光体２７は、基板２８の表面に、特定の波長領域で発光する多数の赤外線ＬＥＤ２９が、例えば千鳥格子状に密に配列して構成され、赤外線ＬＥＤ２９が発光した光（赤外線）は、開口部２６を介して車両２０のナンバープレート２２近傍に向けて照射される。   As shown in FIG. 3, the infrared projector 15 has a configuration in which a planar light emitting body 27 is accommodated in a substantially rectangular box-shaped housing 25 having an opening 26 on one vertical surface. The planar light-emitting body 27 is formed by arranging a large number of infrared LEDs 29 emitting light in a specific wavelength region on the surface of the substrate 28 in, for example, a staggered pattern, and light (infrared rays) emitted from the infrared LEDs 29 is The light is irradiated toward the vicinity of the license plate 22 of the vehicle 20 through the opening 26.

次に、このように構成された本発明の実施形態に係る車両監視システム１０について、制御手順について説明する。図４は、本発明の実施の形態に係る車両監視システムの制御手順を説明するためのフローチャートである。   Next, a control procedure will be described for the vehicle monitoring system 10 according to the embodiment of the present invention configured as described above. FIG. 4 is a flowchart for explaining a control procedure of the vehicle monitoring system according to the embodiment of the present invention.

車両監視システム１０は、車両２０がレーザーセンサ１３を通過すると、レーザー照射部１３ａから照射されるレーザーＬが車両２０で遮られ、レーザー受光部１３ｂで受光できなくなることで、車両２０の通過を検知する（ステップＳ１０１）。輝度センサ１４は、レーザーセンサ１３からの車両通過信号に基づいて、この車両２０のナンバープレート２２の輝度値Ｂを測定し（ステップＳ１０２）、予め設定されている閾値Ｓと比較する（ステップＳ１０３）。   When the vehicle 20 passes the laser sensor 13, the vehicle monitoring system 10 detects the passage of the vehicle 20 because the laser L emitted from the laser irradiation unit 13a is blocked by the vehicle 20 and cannot be received by the laser light receiving unit 13b. (Step S101). The luminance sensor 14 measures the luminance value B of the license plate 22 of the vehicle 20 based on the vehicle passing signal from the laser sensor 13 (step S102) and compares it with a preset threshold value S (step S103). .

測定されたナンバープレート２２の輝度値Ｂが閾値Ｓより低いと（Ｓ＞Ｂ）、ステップＳ１０４でこのナンバープレート２２は非発光型ナンバープレートであると判定され、車両監視カメラ１６のシャッタを開いてナンバープレート２２の撮像を開始する（ステップＳ１０５）。   If the measured luminance value B of the license plate 22 is lower than the threshold value S (S> B), it is determined in step S104 that the license plate 22 is a non-light emitting license plate, and the shutter of the vehicle monitoring camera 16 is opened. Imaging of the license plate 22 is started (step S105).

赤外線投光器１５は、車両監視カメラ１６のシャッタの作動に同期して、相対的に高い発光強度である第１の発光強度ＢＨで赤外線を発光する（ステップＳ１０６）。そして、車両監視カメラ１６のシャッタを閉じた後（ステップＳ１０７）、再び、輝度センサ１４がナンバープレート２２の輝度値Ｂ１を測定し（ステップＳ１０８）、前回測定した輝度値Ｂと現在の輝度値Ｂ１とを比較して輝度値変化の有無を判断する（ステップＳ１０９）。   The infrared projector 15 emits infrared light at a first light emission intensity BH that is a relatively high light emission intensity in synchronization with the operation of the shutter of the vehicle monitoring camera 16 (step S106). Then, after closing the shutter of the vehicle monitoring camera 16 (step S107), the luminance sensor 14 again measures the luminance value B1 of the license plate 22 (step S108), and the previously measured luminance value B and the current luminance value B1. To determine whether or not there is a change in luminance value (step S109).

輝度値の変化がある場合（Ｂ１≠Ｂ）、ステップＳ１０５の前に戻り、シャッタを開閉すると共に、これに同期させて赤外線投光器１５から相対的に高い発光強度である第１の発光強度ＢＨで赤外線を発光してナンバープレート２２を撮像する。また、輝度値Ｂの変化がない場合（Ｂ１＝Ｂ）、ステップＳ１０１の前に戻り次の車両２０の通過を待つ。   When there is a change in the brightness value (B1 ≠ B), the process returns to step S105, the shutter is opened and closed, and the first light emission intensity BH, which is a relatively high light emission intensity from the infrared projector 15, is synchronized with this. The license plate 22 is imaged by emitting infrared rays. If there is no change in the brightness value B (B1 = B), the process returns to step S101 and waits for the next vehicle 20 to pass.

一方、ステップＳ１０３で、測定されたナンバープレート２２の輝度値Ｂが、閾値Ｓより高いと（Ｓ＜Ｂ）、ステップＳ２０４でこのナンバープレート２２は自発光型ナンバープレートであると判定され、車両監視カメラ１６のシャッタを開いてナンバープレート２２の撮像を開始する（ステップＳ２０５）。   On the other hand, if the measured brightness value B of the license plate 22 is higher than the threshold value S (S <B) in step S103, it is determined in step S204 that the license plate 22 is a self-luminous license plate, and vehicle monitoring is performed. The shutter of the camera 16 is opened and imaging of the license plate 22 is started (step S205).

赤外線投光器１５は、車両監視カメラ１６のシャッタの作動に同期して、相対的に低い発光強度である第２の発光強度ＢＬで赤外線を発光する（ステップＳ２０６）。そして、車両監視カメラ１６のシャッタを閉じた後（ステップＳ２０７）、再び、輝度センサ１４がナンバープレート２２の輝度値Ｂ１を測定し（ステップＳ２０８）、前回測定した輝度値Ｂと現在の輝度値Ｂ１とを比較して輝度値変化の有無を判断する（ステップＳ２０９）。   The infrared projector 15 emits infrared light with the second light emission intensity BL, which is a relatively low light emission intensity, in synchronization with the operation of the shutter of the vehicle monitoring camera 16 (step S206). Then, after closing the shutter of the vehicle monitoring camera 16 (step S207), the luminance sensor 14 again measures the luminance value B1 of the license plate 22 (step S208), and the previously measured luminance value B and the current luminance value B1. To determine whether or not there is a change in luminance value (step S209).

輝度値の変化がある場合（Ｂ１≠Ｂ）、ステップＳ２０５の前に戻り、シャッタを開閉すると共に、これに同期させて赤外線投光器１５から相対的に低い発光強度である第２の発光強度ＢＬで赤外線を発光してナンバープレート２２を撮像する。輝度値Ｂの変化がない場合（Ｂ１＝Ｂ）、ステップＳ１０１の前に戻り次の車両２０の通過を待つ。   When there is a change in the brightness value (B1 ≠ B), the process returns to step S205 to open and close the shutter, and in synchronization with this, the second light emission intensity BL that is a relatively low light emission intensity from the infrared projector 15 is used. The license plate 22 is imaged by emitting infrared rays. If there is no change in the brightness value B (B1 = B), the process returns to step S101 and waits for the next vehicle 20 to pass.

このような手順で制御することにより、車両監視システム１０は、図５に示すように作動する。図５は本発明の実施の形態に係る車両監視システムの動作を説明するためのタイムチャートである。   By controlling in such a procedure, the vehicle monitoring system 10 operates as shown in FIG. FIG. 5 is a time chart for explaining the operation of the vehicle monitoring system according to the embodiment of the present invention.

車両２０がレーザーセンサ１３を通過すると、図５（ａ）に示すように、車両２０の通過信号Ｐが出力され、これにより、図５（ｂ）（左半分）に示すように、輝度センサ１４がナンバープレート２２の輝度値Ｂを測定する。図５（ｃ）、（ｄ）に示すように、輝度値Ｂが閾値Ｓより低いと（Ｓ＞Ｂ）、非発光型ナンバープレート２２と判断して、赤外線投光器１５は相対的に高い発光強度である第１の発光強度ＢＨで赤外線を発光してナンバープレート２２を明るく照明すると共に、車両監視カメラ１６のシャッタを開閉してナンバープレート２２を撮像する。このナンバープレート２２の撮像は、輝度値Ｂが変化するごとに複数回行われる。   When the vehicle 20 passes through the laser sensor 13, as shown in FIG. 5A, a passing signal P of the vehicle 20 is output, and as a result, as shown in FIG. 5B (left half), the luminance sensor 14 is output. Measures the luminance value B of the license plate 22. As shown in FIGS. 5C and 5D, when the luminance value B is lower than the threshold value S (S> B), the infrared projector 15 determines that the light emitting license plate 22 is used, and the infrared projector 15 has a relatively high emission intensity. The license plate 22 is brightly illuminated by emitting infrared rays with the first emission intensity BH, and the shutter of the vehicle monitoring camera 16 is opened and closed to image the license plate 22. The number plate 22 is imaged a plurality of times each time the luminance value B changes.

一方、図５（ｂ）（右半分）に示すように、輝度値Ｂが閾値Ｓより高いと（Ｓ＜Ｂ）、自発光型ナンバープレート２２と判断して、図５（ｃ）、（ｄ）に示すように、赤外線投光器１５は相対的に低い発光強度である第２の発光強度ＢＬで赤外線を発光してナンバープレート２２を照明すると共に、車両監視カメラ１６のシャッタを開閉してナンバープレート２２を撮像する。このナンバープレート２２の撮像は、輝度値Ｂが変化するごとに複数回行われる。   On the other hand, as shown in FIG. 5B (right half), when the luminance value B is higher than the threshold value S (S <B), it is determined that the light-emitting license plate 22 is used, and FIGS. ), The infrared projector 15 emits infrared rays with a second emission intensity BL, which is a relatively low emission intensity, illuminates the license plate 22, and opens and closes the shutter of the vehicle monitoring camera 16 to open the license plate. 22 is imaged. The number plate 22 is imaged a plurality of times each time the luminance value B changes.

以上説明したように、このような本発明の実施形態に係る車両監視システムによれば、ナンバープレートの輝度値によってナンバープレートの種類を判別し、赤外線投光器が撮像に最適の発光強度で発光するため、ナンバープレートの種類に係わらず、常に鮮明に撮像することが可能となる。   As described above, according to the vehicle monitoring system according to the embodiment of the present invention, the type of the license plate is determined based on the brightness value of the license plate, and the infrared projector emits light with the optimal light emission intensity for imaging. Regardless of the type of license plate, it is always possible to capture a clear image.

尚、本発明は、前述した実施形態に限定されるものではなく、適宜、変形、改良、等が可能である。   In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

１０ 車両監視システム
１１ 道路（路面）
１３ レーザーセンサ
１４ 輝度センサ
１５ 赤外線投光器
１６ 車両監視カメラ
１７ 制御部
２０ 車両
２２ ナンバープレート
２５ 筐体
２６ 開口部
２７ 面状発光体
２８ ＬＥＤ基板
２９ 赤外線ＬＥＤ
Ｂ 輝度値
ＢＨ 第１の発光強度
ＢＬ 第２の発光強度
Ｓ 閾値 10 Vehicle monitoring system 11 Road (road surface)
DESCRIPTION OF SYMBOLS 13 Laser sensor 14 Luminance sensor 15 Infrared projector 16 Vehicle monitoring camera 17 Control part 20 Vehicle 22 Number plate 25 Case 26 Opening part 27 Planar light-emitting body 28 LED board 29 Infrared LED
B Luminance value BH First emission intensity BL Second emission intensity S Threshold

Claims (3)

車両を撮像する車両監視カメラと、前記車両を照明する赤外線投光器と、を有する車両監視システムであって、
路面上を走行する前記車両の通過を検知するレーザーセンサと、
前記車両のナンバープレートの輝度値を測定する輝度センサと、
前記赤外線投光器の発光強度を制御する制御部と、を備え、
前記制御部は、
前記輝度センサによって測定された前記ナンバープレートの前記輝度値が、予め決められた閾値よりも低い場合、相対的に高い発光強度である第１の発光強度で前記赤外線投光器から発光させ、
前記輝度センサによって測定された前記ナンバープレートの前記輝度値が、予め決められた閾値よりも高い場合、前記第１の発光強度より相対的に低い第２の発光強度で前記赤外線投光器から発光させる車両監視システム。 A vehicle monitoring system comprising a vehicle monitoring camera that images a vehicle and an infrared projector that illuminates the vehicle,
A laser sensor for detecting the passage of the vehicle traveling on the road surface;
A brightness sensor for measuring the brightness value of the license plate of the vehicle;
A control unit for controlling the light emission intensity of the infrared projector,
The controller is
When the brightness value of the license plate measured by the brightness sensor is lower than a predetermined threshold, the infrared projector emits light with a first light emission intensity that is a relatively high light emission intensity,
When the brightness value of the license plate measured by the brightness sensor is higher than a predetermined threshold, the vehicle emits light from the infrared projector with a second light emission intensity relatively lower than the first light emission intensity. Monitoring system. 請求項１に記載の車両監視システムであって、
前記閾値は、前記輝度センサによって測定される自発光型ナンバープレートの輝度値と、非発光型ナンバープレートの輝度値とを判別可能である車両監視システム。 The vehicle monitoring system according to claim 1,
The vehicle monitoring system, wherein the threshold value can distinguish between a luminance value of a self-luminous license plate measured by the luminance sensor and a luminance value of a non-luminous license plate. 請求項１に記載の車両監視システムであって、
前記赤外線投光器は、
一方の垂直面に開口部を有する方形箱形状の筐体と、
前記筐体の開口部近傍に設けられ、複数の赤外線ＬＥＤを平面状に配列したＬＥＤ基板から構成される面状発光体と、具備した車両監視システム。 The vehicle monitoring system according to claim 1,
The infrared projector is
A rectangular box-shaped housing having an opening on one vertical surface;
A vehicle monitoring system provided with a planar light emitter that is provided in the vicinity of the opening of the housing and is configured by an LED substrate in which a plurality of infrared LEDs are arranged in a plane.
JP2010011458A 2010-01-21 2010-01-21 Vehicle monitoring system Expired - Fee Related JP5429988B2 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015129676A1 (en) * 2014-02-26 2015-09-03 三菱重工業株式会社 Lighting system, license-plate recognition system, lighting method, and program
RU2563102C1 (en) * 2014-02-12 2015-09-20 Закрытое акционерное общество "ЭЛВИС-НеоТек" System and method for determination of vehicle license plate
JP2017116779A (en) * 2015-12-25 2017-06-29 スリーエム イノベイティブ プロパティズ カンパニー Retroreflective license plate and retroreflective sheet

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01265190A (en) * 1988-04-15 1989-10-23 Matsushita Electric Ind Co Ltd Led type infrared-ray projector
JPH07121794A (en) * 1993-10-22 1995-05-12 Nippon Signal Co Ltd:The Vehicle registered number recognition device
JPH09282447A (en) * 1996-04-18 1997-10-31 Mitsubishi Electric Corp Picture recognizing device
JP2000163696A (en) * 1998-11-25 2000-06-16 Mitsubishi Electric Corp Picture recognizing device
JP2002216290A (en) * 2001-01-19 2002-08-02 Nissin Electric Co Ltd Number plate reader
JP2002344952A (en) * 2001-05-22 2002-11-29 Fujitsu Ltd License plate recognition device and method
JP2006190198A (en) * 2005-01-07 2006-07-20 Mitsubishi Heavy Ind Ltd Portable vehicle number recognizing device and vehicle number recognizing method using the same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01265190A (en) * 1988-04-15 1989-10-23 Matsushita Electric Ind Co Ltd Led type infrared-ray projector
JPH07121794A (en) * 1993-10-22 1995-05-12 Nippon Signal Co Ltd:The Vehicle registered number recognition device
JPH09282447A (en) * 1996-04-18 1997-10-31 Mitsubishi Electric Corp Picture recognizing device
JP2000163696A (en) * 1998-11-25 2000-06-16 Mitsubishi Electric Corp Picture recognizing device
JP2002216290A (en) * 2001-01-19 2002-08-02 Nissin Electric Co Ltd Number plate reader
JP2002344952A (en) * 2001-05-22 2002-11-29 Fujitsu Ltd License plate recognition device and method
JP2006190198A (en) * 2005-01-07 2006-07-20 Mitsubishi Heavy Ind Ltd Portable vehicle number recognizing device and vehicle number recognizing method using the same

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2563102C1 (en) * 2014-02-12 2015-09-20 Закрытое акционерное общество "ЭЛВИС-НеоТек" System and method for determination of vehicle license plate
WO2015129676A1 (en) * 2014-02-26 2015-09-03 三菱重工業株式会社 Lighting system, license-plate recognition system, lighting method, and program
JP2015161963A (en) * 2014-02-26 2015-09-07 三菱重工業株式会社 Lighting system, number plate recognition system, lighting method, and program
GB2539338A (en) * 2014-02-26 2016-12-14 Mitsubishi Heavy Ind Mechatronics Systems Ltd Lighting system, license-plate recognition system, lighting method, and program
GB2539338B (en) * 2014-02-26 2021-06-16 Mitsubishi Heavy Ind Mach Systems Ltd Lighting system, license-plate recognition system, lighting method, and program
JP2017116779A (en) * 2015-12-25 2017-06-29 スリーエム イノベイティブ プロパティズ カンパニー Retroreflective license plate and retroreflective sheet

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