JPH0530144Y2 - - Google Patents
Info
- Publication number
- JPH0530144Y2 JPH0530144Y2 JP1987119534U JP11953487U JPH0530144Y2 JP H0530144 Y2 JPH0530144 Y2 JP H0530144Y2 JP 1987119534 U JP1987119534 U JP 1987119534U JP 11953487 U JP11953487 U JP 11953487U JP H0530144 Y2 JPH0530144 Y2 JP H0530144Y2
- Authority
- JP
- Japan
- Prior art keywords
- vehicle
- light
- inter
- measured
- measuring device
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 33
- 238000005259 measurement Methods 0.000 claims description 8
- 239000004065 semiconductor Substances 0.000 description 8
- 230000010287 polarization Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000007257 malfunction Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Optical Radar Systems And Details Thereof (AREA)
Description
【考案の詳細な説明】
［産業上の利用分野］
本考案は車間距離測定装置に係り、特に送出し
た光パルスの反射光を受光するまでの伝搬遅延時
間に基づいて車間距離を測定する車間距離測定装
置に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inter-vehicle distance measuring device, and in particular, an inter-vehicle distance measuring device that measures an inter-vehicle distance based on the propagation delay time until the reflected light of a transmitted light pulse is received. Concerning a measuring device.
［従来の技術］
従来、車間距離を測定する場合、第７図の如
く、測定装置５を備えた車両１０から、該車両１
０の前方を走行する車両１２に向けて光パルス１
４を送出し、この光パルス１４の車両１２による
反射光を車両１０の測定装置５で受光し、その
送、受パルスの伝搬遅延時間を測定することによ
つて車両１０と１２間の距離を演算する方法が用
いられている。[Prior Art] Conventionally, when measuring the inter-vehicle distance, as shown in FIG.
A light pulse 1 is directed toward a vehicle 12 running in front of the vehicle 0.
The distance between the vehicles 10 and 12 is determined by transmitting a light pulse 14 and receiving the reflected light of the light pulse 14 by the vehicle 12 by the measuring device 5 of the vehicle 10, and measuring the propagation delay time of the transmitted and received pulses. A method of calculating is used.
なお、この装置に関するものとして、特開昭58
−37576号公報記載の技術がある。 Regarding this device, please refer to Japanese Patent Application Laid-open No. 58
There is a technique described in the -37576 publication.
［考案が解決しようとする問題点］
しかし、従来の車間距離測定装置は、第７図に
示すように、送出した光パルスの目標とする車両
以外の物体（例えばガードレール１６、対向車両
１８等）からの反射光、あるいは車両１０と同一
方式の車間距離測定装置を備えた対向車両１８が
発する光パルスを受信可能であるため、これによ
つて車間距離測定装置が誤動作する虞れがある。[Problems to be solved by the invention] However, as shown in FIG. 7, the conventional inter-vehicle distance measuring device detects objects other than the target vehicle of the transmitted light pulse (for example, guardrail 16, oncoming vehicle 18, etc.). Since it is possible to receive reflected light from a vehicle 10 or a light pulse emitted by an oncoming vehicle 18 equipped with the same type of inter-vehicle distance measuring device as the vehicle 10, this may cause the inter-vehicle distance measuring device to malfunction.
本考案は、測定対象車両以外の物体からの反射
光等の影響による測定誤差が生じないようにした
車間距離測定装置を提供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide an inter-vehicle distance measuring device that does not cause measurement errors due to the influence of reflected light from objects other than the vehicle to be measured.
［問題点を解決するための手段］
上記目的を達成するために、本考案は、測定車
両から被測定車両に向けて光を送出し、前記被測
定車両からの反射光を前記測定車両で受光して光
の伝播時間から車間距離を測定する車間距離測定
装置において、前記被測定車両に設けられて前記
測定車両からの光を偏光させると共に再帰反射し
て出力する光トランスポンダと、前記測定車両に
設けられて前記光トランスポンダによつて偏光さ
れた光のみを受光する光学系と、を備えて構成し
てある。[Means for Solving the Problems] In order to achieve the above object, the present invention transmits light from a measurement vehicle toward a vehicle to be measured, and receives reflected light from the vehicle to be measured by the vehicle to be measured. The inter-vehicle distance measuring device measures the inter-vehicle distance from the propagation time of light, which comprises: an optical transponder installed in the vehicle to be measured that polarizes light from the vehicle to be measured, and outputs the reflected light by retroreflecting; and an optical system that receives only the light polarized by the optical transponder.
［作用］
本考案によれば、光トランスポンダによつて、
測定車両より送出された光が偏光されると共に再
帰反射して測定車両側へ出力される。また、光学
系は、光トランスポンダによつて偏光された光の
みを受光する。したがつて、偏光されていないガ
ードレール、対向車等よりの反射光は受光部に入
光されることはないため、誤動作の発生が防止さ
れる。[Operation] According to the present invention, by the optical transponder,
The light sent out from the measurement vehicle is polarized, retroreflected, and output to the measurement vehicle. Further, the optical system receives only the light polarized by the optical transponder. Therefore, unpolarized light reflected from a guardrail, an oncoming vehicle, etc. will not enter the light receiving section, thereby preventing malfunctions.
［実施例］
以下、図面を参照して本考案の実施例を詳細に
説明する。[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
第１図は本考案による車間距離測定装置の一実
施例を示すものであり、被測定車両１２の後部に
は、測定車両１０より発せられたレーザビーム２
４の一部を反射して再び測定車両１０の受光部方
向へ射出させる光トランスポンダ２０が装着され
ている。さらに、測定車両１０の前部には光学系
２２が設けられている。 FIG. 1 shows an embodiment of the inter-vehicle distance measuring device according to the present invention, in which a laser beam 2 emitted from the measuring vehicle 10 is placed at the rear of the vehicle 12 to be measured.
An optical transponder 20 is mounted to reflect a portion of the light beam 4 and emit it again toward the light receiving section of the measuring vehicle 10. Furthermore, an optical system 22 is provided at the front of the measurement vehicle 10.
第２図は光トランスポンダ２０の詳細を示すも
のである。この光トランスポンダ２０は、再帰反
射する再帰反射系としてのコーナキユーブプリズ
ム２６と、このプリズムの入射面（出射面を兼ね
る）に装着された1/4波長板２８とより成る。コ
ーナキユーブプリズム２６は、入射光が有効口径
に対していかなる角度で入射しても、その反射光
が入射光に平行で且つ逆向きになる構成を有し
（再帰反射）、有効口径の全域に入射された光線の
反射光３２は入射光３０に完全に平行になる。 FIG. 2 shows details of the optical transponder 20. This optical transponder 20 consists of a corner cube prism 26 as a retroreflection system that performs retroreflection, and a 1/4 wavelength plate 28 attached to the entrance surface (also serving as the exit surface) of this prism. The corner cube prism 26 has a configuration in which, no matter what angle the incident light is incident on the effective aperture, the reflected light is parallel to and in the opposite direction to the incident light (retroreflection), and the entire area of the effective aperture is The reflected light 32 of the incident light ray becomes completely parallel to the incident light 30.
1/4波長２８は、相互に垂直な方向に振動する
直線偏光の間に1/4波長の光路差が生ずるように
厚さが決定された複屈曲板で、その材料には雲
母、水晶等が用いられる。 The 1/4 wavelength 28 is a birefringent plate whose thickness is determined so that an optical path difference of 1/4 wavelength occurs between linearly polarized lights vibrating in directions perpendicular to each other, and its material includes mica, quartz, etc. is used.
第３図は光学系２２の詳細を示すものであり、
レーザ光（送出光）３４を発振する半導体レーザ
３６のレーザ光射出側には偏光ビームスプリツタ
３８および集光レンズ４０が順次配設されてい
る。偏光ビームスプリツタ３８は、半導体レーザ
３６からのレーザ光３４をそのまま通過させると
共に、光トランスポンダ２０からの反射光４２を
レーザ光３４に対し直角な方向に反射させる。ま
た、集光レンズ４０は半導体レーザ３６からのレ
ーザ光３４を特定のビーム開き角を持つた射出光
とすると共に、光トランスポンダ２０よりの反射
光４２を所定位置に収束させる。集光レンズ４０
による反射光４２の収束位置に受光素子４４が配
設されている。 FIG. 3 shows details of the optical system 22,
A polarizing beam splitter 38 and a condensing lens 40 are sequentially arranged on the laser beam emission side of a semiconductor laser 36 that oscillates a laser beam (transmission light) 34. The polarizing beam splitter 38 allows the laser beam 34 from the semiconductor laser 36 to pass through as it is, and reflects the reflected light 42 from the optical transponder 20 in a direction perpendicular to the laser beam 34. Further, the condenser lens 40 converts the laser beam 34 from the semiconductor laser 36 into an emitted beam having a specific beam aperture angle, and converges the reflected light 42 from the optical transponder 20 at a predetermined position. Condensing lens 40
A light receiving element 44 is disposed at a position where the reflected light 42 is converged.
なお、上記の車間距離測定装置では半導体レー
ザ３６による光パルスの発生タイミングから受光
素子４４による反射光の受光タイミングまでの時
間から車間距離を算出するわけであるが、ここで
はその演算部の構成については説明を省略する。 In addition, in the above-mentioned inter-vehicle distance measuring device, the inter-vehicle distance is calculated from the time from the timing of the generation of the optical pulse by the semiconductor laser 36 to the timing of the reception of the reflected light by the light-receiving element 44. Here, we will explain the configuration of the calculation section. The explanation will be omitted.
次に、第４図乃至第６図を参照して上記実施例
の作用について説明する。 Next, the operation of the above embodiment will be explained with reference to FIGS. 4 to 6.
光学系２２の半導体レーザ３６が図示しない駆
動回路によつて駆動されると、第４図に示すよう
に、Ｘ方向を偏光面とする直線偏光のレーザ光３
４が発生し、その全量が偏光ビームスプリツタ３
８を通過したのち、集光レンズ４０で特定のビー
ム開き角を持つた射出光として被測定車両１２に
向けて送出される。この射出光の一部は被測定車
両１２の後部に装着された光トランスポンダ２０
に入射する。入射光は、1/4波長板２８を通過し
て円偏光になり、さらにコーナキューブプリズム
２６によつて３回の全反射が行なわれて、入射光
３０に対し偏光面が180度回転して反射される。
このコーナキユーブプリズム２６による反射光
は、再び1/4波長板２８を通過し、その際に円偏
光４８から直線偏光５０にされ、反射光として光
トランスポンダ２０から測定車両１０の光学系２
２に向けて反射される。直線偏光５０は、Ｙ方向
を偏光面とし、入射光に対し偏光面が90度回転し
ている。 When the semiconductor laser 36 of the optical system 22 is driven by a drive circuit (not shown), a linearly polarized laser beam 3 whose polarization plane is in the X direction is generated as shown in FIG.
4 is generated, and the entire amount is transmitted to the polarizing beam splitter 3.
8, the light beam passes through the condenser lens 40 and is emitted toward the vehicle to be measured 12 as an emitted light beam having a specific beam aperture angle. A part of this emitted light is transmitted to an optical transponder 20 mounted on the rear of the vehicle 12 to be measured.
incident on . The incident light passes through the 1/4 wavelength plate 28 and becomes circularly polarized light, and is then totally reflected three times by the corner cube prism 26, so that the plane of polarization is rotated 180 degrees relative to the incident light 30. reflected.
The reflected light from the corner cube prism 26 passes through the 1/4 wavelength plate 28 again, at which time the circularly polarized light 48 becomes linearly polarized light 50, and the reflected light is transmitted from the optical transponder 20 to the optical system of the measuring vehicle 10.
It is reflected towards 2. The linearly polarized light 50 has a polarization plane in the Y direction, and the polarization plane is rotated by 90 degrees with respect to the incident light.
光トランスポンダ２０からの反射光は、集光レ
ンズ４０で集光され、さらに偏光ビームスプリツ
タ３８の接合面によつて受光素子４４方向へ全反
射される。この偏光ビームスプリツタ３８には光
トランスポンダ２０の反射光のほか、ガードレー
ル１６や対向車両等からの反射光も入光する。し
かし、これらの光はパワーが小さくかつレーザ光
３４と同一の直線偏光であるため、偏光ビームス
プリツタ３８の接合面では反射されずに直進する
ため、受光素子４４に入光することが無い。した
がつて光トランスポンダ２０からの反射光のみが
受光素子４４に受光される。このため、従来のよ
うに被測定車両以外からの反射光等による影響が
除去され、誤動作等を招くことがない。 The reflected light from the optical transponder 20 is condensed by the condenser lens 40 and further totally reflected by the joint surface of the polarizing beam splitter 38 toward the light receiving element 44 . In addition to the reflected light from the optical transponder 20, reflected light from the guardrail 16, oncoming vehicles, etc. also enters the polarizing beam splitter 38. However, since these lights have low power and are the same linearly polarized light as the laser light 34, they are not reflected at the junction surface of the polarizing beam splitter 38 and travel straight, so they do not enter the light receiving element 44. Therefore, only the reflected light from the optical transponder 20 is received by the light receiving element 44. Therefore, the influence of reflected light etc. from sources other than the vehicle to be measured is removed, unlike in the past, and malfunctions and the like are not caused.
受光素子４４の光一電変換出力に対し、半導体
レーザ３６のレーザ光の発生時点からの経過時
間、すなわち光パルスの発光から受光までの伝搬
遅延時間ｔが演算され、この時間ｔに基づいて下
式から車間距離Ｌが求められる。 The elapsed time from the time when the laser beam of the semiconductor laser 36 is generated, that is, the propagation delay time t from the emission of the optical pulse to the reception of the light pulse, is calculated for the optical-to-electrical conversion output of the light receiving element 44, and the following formula is calculated based on this time t. The inter-vehicle distance L can be calculated from .
Ｌ＝Ｃｔ／２（但し、Ｃは光速）
エラレタ車間距離情報は、例えば、アクセル、
ブレーキ等を自動的に制御し、安全な車間距離を
保つためのオートドライブシステムに用いること
ができる。 L=Ct/2 (C is the speed of light) Erareta inter-vehicle distance information is, for example, an accelerator,
It can be used in auto-drive systems that automatically control brakes and other functions to maintain a safe distance between vehicles.
本考案によれば、光トランスポンダの反射光の
みを受光部に入射させることができるため、従来
に比べ発光素子の光出力が小さくて済み、低価格
の半導体レーザを用いることができる。これによ
つて、駆動回路の簡略化が図られ、信頼性及び耐
久性の向上が可能になる。 According to the present invention, since only the reflected light from the optical transponder can be made incident on the light receiving section, the light output of the light emitting element can be smaller than that of the conventional device, and a low-cost semiconductor laser can be used. This simplifies the drive circuit and improves reliability and durability.
［考案の効果］
以上説明したように、本考案によれば、車間距
離測定用の光を被測定車両に設けた光トランスポ
ンダによつて偏光及び再帰反射させ、この偏光さ
れた光のみを受光するようにしているため、被測
定車両以外の物体からの反射光及び直接光に起因
する誤動作を防止することができる、という優れ
た効果を有する。[Effects of the invention] As explained above, according to the invention, the light for measuring the inter-vehicle distance is polarized and retroreflected by the optical transponder installed in the vehicle to be measured, and only this polarized light is received. This has the excellent effect of preventing malfunctions caused by reflected light and direct light from objects other than the vehicle to be measured.
第１図は本考案による車間距離測定装置の一実
施例を示す構成図、第２図は本考案に係る光トラ
ンスポンダの構成を示す断面図、第３図は本考案
に係る光学系の構成を示す断面図、第４図はレー
ザビームの偏光状態を示す説明図、第５図は光ト
ランスポンダにおける偏光状態を示す説明図、第
６図は偏光ビームスプリツタにおける偏光状態を
示す説明図、第７図は従来の車間距離測定装置に
よる距離測定方法を説明する説明図である。
１０……測定車両、１２……被測定車両、２０
……光トランスポンダ、２２……光学系、２６…
…コーナキユーブプリズム、２８……1/4波長板、
３６……半導体レーザ、３８……偏光ビームスプ
リツタ、４４……受光素子。
Fig. 1 is a block diagram showing an embodiment of the inter-vehicle distance measuring device according to the present invention, Fig. 2 is a sectional view showing the structure of the optical transponder according to the present invention, and Fig. 3 is a diagram showing the structure of the optical system according to the present invention. FIG. 4 is an explanatory diagram showing the polarization state of the laser beam, FIG. 5 is an explanatory diagram showing the polarization state in the optical transponder, FIG. 6 is an explanatory diagram showing the polarization state in the polarizing beam splitter, and FIG. The figure is an explanatory diagram illustrating a distance measuring method using a conventional inter-vehicle distance measuring device. 10... Measurement vehicle, 12... Vehicle to be measured, 20
...Optical transponder, 22...Optical system, 26...
...corner cube prism, 28...1/4 wavelength plate,
36... Semiconductor laser, 38... Polarizing beam splitter, 44... Light receiving element.
Claims (1)
し、前記被測定車両からの反射光を前記測定車
両で受光して光の伝播時間から車間距離を測定
する車間距離測定装置において、前記被測定車
両に設けられて前記測定車両からの光を偏光さ
せると共に再帰反射して出力する光トランスポ
ンダと、前記測定車両に設けられて前記光トラ
ンスポンダによつて偏光された光のみを受光す
る光学系と、を備えた車間距離測定装置。 (2) 前記光トランスポンダは、再帰反射する再帰
反射系と、該再帰反射系の入出力側に配置され
た1/4波長板とより成る実用新案登録請求の範
囲第(1)項に記載の車間距離測定装置。[Claims for Utility Model Registration] (1) Light is transmitted from a measurement vehicle toward a vehicle to be measured, and the reflected light from the vehicle to be measured is received by the vehicle to be measured, and the inter-vehicle distance is measured from the propagation time of the light. In the inter-vehicle distance measuring device, an optical transponder is provided on the vehicle to be measured and polarizes light from the measurement vehicle, and outputs the light by retroreflecting it; An inter-vehicle distance measuring device equipped with an optical system that receives only the light that is received by the vehicle. (2) The optical transponder comprises a retroreflective system that performs retroreflection, and a quarter-wave plate disposed on the input and output sides of the retroreflection system, as set forth in claim (1) of the utility model registration claim. Inter-vehicle distance measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987119534U JPH0530144Y2 (en) | 1987-08-04 | 1987-08-04 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987119534U JPH0530144Y2 (en) | 1987-08-04 | 1987-08-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6425784U JPS6425784U (en) | 1989-02-13 |
| JPH0530144Y2 true JPH0530144Y2 (en) | 1993-08-02 |
Family
ID=31364848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1987119534U Expired - Lifetime JPH0530144Y2 (en) | 1987-08-04 | 1987-08-04 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0530144Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6296271B2 (en) * | 2013-01-08 | 2018-03-20 | 三菱重工業株式会社 | Measuring system and measuring method |
| WO2019230890A1 (en) * | 2018-05-30 | 2019-12-05 | 富士フイルム株式会社 | Signal detection system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6168574A (en) * | 1984-09-13 | 1986-04-08 | Fujitsu Ten Ltd | Optical type sensor system |
-
1987
- 1987-08-04 JP JP1987119534U patent/JPH0530144Y2/ja not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6168574A (en) * | 1984-09-13 | 1986-04-08 | Fujitsu Ten Ltd | Optical type sensor system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6425784U (en) | 1989-02-13 |
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