JPS6371674A - Laser distance measuring instrument - Google Patents
Laser distance measuring instrumentInfo
- Publication number
- JPS6371674A JPS6371674A JP21741986A JP21741986A JPS6371674A JP S6371674 A JPS6371674 A JP S6371674A JP 21741986 A JP21741986 A JP 21741986A JP 21741986 A JP21741986 A JP 21741986A JP S6371674 A JPS6371674 A JP S6371674A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- light
- laser
- modulation
- laser light
- 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.)
- Pending
Links
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 239000000284 extract Substances 0.000 claims 1
- 230000010355 oscillation Effects 0.000 abstract description 8
- 238000005259 measurement Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Landscapes
- Optical Radar Systems And Details Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、レーザー光を用いて対象物までの距離を測
定するレーザー測距装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a laser distance measuring device that measures the distance to an object using laser light.
従来の技術
対象物までの絶対距離をレーザーを用いて測定すること
はロボットの遠隔操作のための視覚情報源として最近注
目されている。このようなレーザー測距装置のなかにＦ
Ｍ−ＣＷレーザーレーダと呼ばれる方式がある。この方
式に関しては例えばアイイーイーイージャーナルオブク
ウオンタムエレクトロニクスＱＥ−８巻９１〜９２頁、
１９７２年 （■ＥＥＥ Ｊ、 ＱｕａｎｔｕｍＥ］
ｅｃｔｒｏｎｉｃｓ、 ｖｏｌ、ＱＥ−８、ｐｐ９１
〜９２．１９７２）に記載されている。以下、第４図を
参照して、従来のＦＭ−ＣＷレーザーレーダについて説
明する。BACKGROUND OF THE INVENTION Measuring the absolute distance to an object using a laser has recently attracted attention as a visual information source for remote control of robots. Among such laser distance measuring devices, F
There is a method called M-CW laser radar. Regarding this method, for example, IEE Journal of Quantum Electronics QE-8, pp. 91-92,
1972 (■EEE J, QuantumE]
electronics, vol, QE-8, pp91
~92.1972). Hereinafter, a conventional FM-CW laser radar will be explained with reference to FIG.
第４図においてレーザー１の共振器を構成する全反射鏡
２をピエゾ素子３によって保持する。ピエゾ素子３にか
かる電圧を変調用電源４によって変化させると、共振器
長の変化のためにレーザー光の発振周波数は変調される
。この様子を第５図に示す。変調用電源４に三角波電圧
を印加すると、第５図（ａｌＫ示したようにレーザー光
の発振周波数はｆｌからｆ、に直線的に変化する。図中
実線は送信波、破線は反射波を示し、送信後反射波を受
信するまでの時間ΔｔはΔｔ＝２Ｌで表わされる。こＣ
のように変調されたレーザー光を第４図に示したように
対象物７に照射する。対象物からの散乱光を部分反射鏡
６によって受光し、検圧器９に導く。In FIG. 4, a total reflection mirror 2 constituting a resonator of a laser 1 is held by a piezo element 3. When the voltage applied to the piezo element 3 is changed by the modulation power source 4, the oscillation frequency of the laser beam is modulated due to the change in the resonator length. This situation is shown in FIG. When a triangular wave voltage is applied to the modulation power source 4, the oscillation frequency of the laser beam changes linearly from fl to f as shown in Figure 5 (alK). In the figure, the solid line shows the transmitted wave and the broken line shows the reflected wave. , the time Δt from transmitting to receiving the reflected wave is expressed as Δt=2L.The laser beam modulated as shown in C is irradiated onto the object 7 as shown in Fig. 4. The scattered light is received by a partial reflecting mirror 6 and guided to a pressure detector 9.
他方、レーザー光の一部を参照光としてビームスプリッ
タ−５によって取り出し、検出器９に導（。On the other hand, a part of the laser beam is taken out as a reference beam by a beam splitter 5 and guided to a detector 9 (.
レンズ８はレーザー光の集光のために用いている。Lens 8 is used to condense laser light.
検出されたビート信号の周波数は第５図（ｂ）のように
なり、その周波数は対象物までの距離に比例する。すな
わち、周波数偏移量△ｆ＝ｆ、−ｆ、、変調のくり返し
周波数をｆ、、、ビート信号の周波数をｆｂ、対象物ま
での距離をＬとすると
という関係が成り立つ。ここでＣは光の速度である。従
って、周波数分析器１０によってビート信号の周波数を
測定すれば対象物までの距離が求まるわけである。The frequency of the detected beat signal is as shown in FIG. 5(b), and the frequency is proportional to the distance to the object. That is, the following relationships hold: frequency deviation amount Δf=f, -f, the repetition frequency of modulation is f, the frequency of the beat signal is fb, and the distance to the object is L. Here C is the speed of light. Therefore, by measuring the frequency of the beat signal with the frequency analyzer 10, the distance to the object can be determined.
発明が解決しようとする問題点
以上のような構成において全反射鋼２により共振器長を
変化させ、レーザー光の周波数を変調させる方式ではピ
エゾ素子の時間応答性の点から高速なくり返しが不可能
であり、 ｆ、は１ｋＨｚ以下となり、測距精度は制限
を受ける。また、ピエゾ素子が印加電圧に対して直線的
に変化しないといった問題も測距精度を低下させている
。Problems to be Solved by the Invention In the above-mentioned configuration, high-speed repetition is impossible due to the time response of the piezo element with the method of changing the resonator length using the total reflection steel 2 and modulating the frequency of the laser beam. , f is less than 1 kHz, and the distance measurement accuracy is limited. Further, the problem that the piezo element does not change linearly with the applied voltage also reduces distance measurement accuracy.
本発明は以上のような問題点を解決するものであり、精
度のよいレーザー測距装置を提供するものである。The present invention solves the above-mentioned problems and provides a highly accurate laser distance measuring device.
問題点を解決するための手段
本発明はレーザー共振器の出力レーザー光を共振器の外
部に設置した音響光学光変調器を用いて周波数変調し、
周波数変調されたレーザー光の一部を参照光としてとり
出すとともに被測定物に照射し、反射光と参照光との周
波数差を検出するようにしたものである。Means for Solving the Problems The present invention frequency-modulates the output laser light of a laser resonator using an acousto-optic modulator installed outside the resonator.
A part of the frequency-modulated laser light is taken out as a reference light and irradiated onto the object to be measured, and the frequency difference between the reflected light and the reference light is detected.
作 用
本発明は上記構成により音響光学光変調器によって周波
数変調を行なうため、周波数偏移量、変調くり返し数を
大きくとることができるとともに、直線的な周波数変調
が行なえるために、精度よい測距を行なうことができる
。Function: Since the present invention performs frequency modulation using an acousto-optic modulator with the above configuration, it is possible to increase the amount of frequency deviation and the number of repetitions of modulation, and also to perform linear frequency modulation, which allows accurate measurement. You can do distance.
実施例
以下、本発明の一実施例を第１図および第２図にもとづ
いて説明する。第４図と同じ部位には同一番号を付しで
ある。EXAMPLE Hereinafter, an example of the present invention will be explained based on FIGS. 1 and 2. The same parts as in FIG. 4 are given the same numbers.
レーザー１の出力光を音響光学光変調器１１に照射し、
回折光を発生させる。レンズ１３はより高速の変調を行
なえるようにレーザー光を集光するために用いて〜・る
。回折光の周波数は音響光学光変調器１１を駆動する変
調用電源１２の発振周波数だけレーザーの発振周波数か
らシフトしている。従って変調用電源１２の発振周波数
を三角波的に変化させれば、第５図に示したのと同様の
周波数変調が行なえる。ここで重要なことはレンズ１４
によって回折光を平行光に戻すことである。Irradiating the output light of the laser 1 onto the acousto-optic modulator 11,
Generates diffracted light. The lens 13 is used to focus the laser beam so that higher speed modulation can be performed. The frequency of the diffracted light is shifted from the oscillation frequency of the laser by the oscillation frequency of the modulation power source 12 that drives the acousto-optic modulator 11. Therefore, by changing the oscillation frequency of the modulation power source 12 in a triangular wave manner, frequency modulation similar to that shown in FIG. 5 can be performed. The important thing here is lens 14
This is to convert the diffracted light back into parallel light.
何故なら回折光はその周波数変化に応じて回折角が変化
するため偏向を受け、レーザー光は軸ずれを起こしてい
る。しかし、第２図て示したようにレンズ１４の焦点を
音響光学光変調器１１の中心Ｖをト≧イ番汗り壬Ｈ枡会
六１θ、ｈ）へθ−Ｆ磨イに１イ表常に回折光はレンズ
１４によって平行光となり、その周波数のちがいによる
軸ずれΔｄは小さくでき、レンズ１４の焦点距離が極端
に大きくない限り軸ずれ△ｄは問題にならない程度に小
さい。This is because the diffraction angle of the diffracted light changes in accordance with the change in its frequency, so it is deflected and the axis of the laser light is shifted. However, as shown in Figure 2, the focus of the lens 14 is set from the center V of the acousto-optic modulator 11 to The diffracted light is always turned into parallel light by the lens 14, and the axis deviation Δd due to the difference in frequency can be made small, and unless the focal length of the lens 14 is extremely large, the axis deviation Δd is small enough not to be a problem.
ＣＯ，レーザーにおいてＧｅ裂の音響光学光変調器を用
いた場合、周波数偏移量△ｆをＩＦｖｌＨｚ、レンズ１
４の焦点距離をｌｏｏｍとして軸ずれ△ｄは２００μｍ
と非常に小さい値である。When using a Ge-crack acousto-optic modulator in a CO, laser, the frequency deviation amount △f is IFvlHz, lens 1
The focal length of 4 is loom, and the axis deviation △d is 200 μm.
This is a very small value.
以下、周波数変調されたレーザー光を対象物７に照射し
、反射光と参照光とのビート信号の周波数を測定して対
象物までの距離を求めろ構成は第３図の従来例と同様で
ある。（１）式から距離測定精度△Ｌは、ビート信号の
周波数測定精度をΔｆｂとして
となるので、周波数偏移量△ｆ、変調くり返し数ｆ□は
大きいほど距離測定精度はよい値となる。本実施例によ
れば、周波数偏移量、変調くり返し数ともに大きな周波
数変調が可能であり、また、直線的な周波数変調を行な
える。このため精度のよい距離測定を行なうことができ
る。Below, frequency-modulated laser light is irradiated onto the target object 7, and the frequency of the beat signal between the reflected light and the reference light is measured to find the distance to the target object.The configuration is the same as the conventional example shown in Fig. 3. be. From equation (1), the distance measurement accuracy ΔL is determined by setting the frequency measurement accuracy of the beat signal as Δfb. Therefore, the larger the frequency deviation amount Δf and the modulation repetition number f□, the better the distance measurement accuracy becomes. According to this embodiment, frequency modulation with a large amount of frequency shift and a large number of modulation repetitions is possible, and linear frequency modulation can be performed. Therefore, accurate distance measurement can be performed.
第３図には本発明の別の実施例を示す。本実施例が第１
図と異なるのは、スキャナー１５によって周波数変調さ
れたレーザー光の走査を行ない、同じスキャナー１５を
通して対象物７の反射光を検出している点である。本構
成によれば距離画像として三次元情報を得ることができ
る。このような距離画像はロボットの三次元視覚などに
有効である。FIG. 3 shows another embodiment of the invention. This example is the first
The difference from the figure is that a scanner 15 scans with frequency-modulated laser light, and the reflected light from the object 7 is detected through the same scanner 15. According to this configuration, three-dimensional information can be obtained as a distance image. Such distance images are effective for three-dimensional vision of robots.
発明の効果
以上述べたように本発明はレーザー共振器の外部に設置
した音響光学光変調器によって周波数変調されたレーザ
ー光を得、対象物に照射し、反射光の周波数を検出する
ことによって距離を測定する精度よいレーザー測距装置
を提供するものである。Effects of the Invention As described above, the present invention obtains frequency-modulated laser light using an acousto-optic modulator installed outside a laser resonator, irradiates it onto an object, and detects the frequency of the reflected light. The purpose of the present invention is to provide a laser distance measuring device with high accuracy for measuring.
第１図は本発明の一実施例におけるレーザー測距装置の
概略図、第２図は同レーザー測距装置の音響光学光変調
器のための光学系の説明図、第３図は本発明の他の実施
例のレーザー測距装置の概略図、第４図は従来のレーザ
ー測距装置の概略図。
第５図は周波数変調方式レーザー測距装置の原理図であ
る。
１・・・レーザー、２・・・全反射鏡、３・・・ピエゾ
、４゜１２・・・変調用型源、５・・・ビームスプリッ
タ−１６・・・部分反射鏡、７・・・対象物、８．１３
．１４・・・レンズ、９・・・検出器、１０・・・周波
数分析器、】１・・・音響光学光変調器、１５・・・ス
キャナー。
代理人の氏名 弁理士 中 尾 敏 男 ほか１名 Ｎ
′Ｉ、。FIG. 1 is a schematic diagram of a laser ranging device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of an optical system for an acousto-optic modulator of the laser ranging device, and FIG. 3 is a schematic diagram of a laser ranging device according to an embodiment of the present invention. A schematic diagram of a laser distance measuring device according to another embodiment, and FIG. 4 is a schematic diagram of a conventional laser ranging device. FIG. 5 is a diagram showing the principle of a frequency modulation type laser distance measuring device. DESCRIPTION OF SYMBOLS 1...Laser, 2...Total reflection mirror, 3...Piezo, 4゜12...Modulation source, 5...Beam splitter-16...Partial reflection mirror, 7... Object, 8.13
．． 14... Lens, 9... Detector, 10... Frequency analyzer, ]1... Acousto-optic light modulator, 15... Scanner. Name of agent: Patent attorney Toshio Nakao and one other person N'I.
Claims (2)
を周波数変調する音響光学光変調器と、周波数変調され
たレーザー光の一部を参照光として取り出すとともに、
被測定物に照射する手段と、前記参照光と被測定物から
の反射光との周波数差を検出する手段とを具備したこと
を特徴とするレーザー測距装置。(1) A laser light source, an acousto-optic modulator that frequency-modulates the laser light from the laser light source, and extracts a part of the frequency-modulated laser light as a reference light,
1. A laser distance measuring device comprising: means for irradiating an object to be measured; and means for detecting a frequency difference between the reference light and light reflected from the object to be measured.
ーを備えている特許請求の範囲第１項記載のレーザー測
距装置。(2) The laser distance measuring device according to claim 1, wherein the means for irradiating the object to be measured with laser light includes a scanner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21741986A JPS6371674A (en) | 1986-09-16 | 1986-09-16 | Laser distance measuring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21741986A JPS6371674A (en) | 1986-09-16 | 1986-09-16 | Laser distance measuring instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6371674A true JPS6371674A (en) | 1988-04-01 |
Family
ID=16703915
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21741986A Pending JPS6371674A (en) | 1986-09-16 | 1986-09-16 | Laser distance measuring instrument |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6371674A (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1082858A (en) * | 1996-07-15 | 1998-03-31 | Hiromasa Ito | Optical range finder |
| JP2006513399A (en) * | 2002-05-29 | 2006-04-20 | ケント・エル・デインズ | System and method for measuring velocity using frequency modulation of laser power |
| JP2014202716A (en) * | 2013-04-09 | 2014-10-27 | 株式会社日立ハイテクノロジーズ | Distance measuring device |
| JP2019537012A (en) * | 2016-11-30 | 2019-12-19 | ブラックモア センサーズ アンド アナリティクス インク． | Method and system for Doppler correction of Doppler detection and optical chirp distance detection |
| JP2021510834A (en) * | 2018-01-16 | 2021-04-30 | ロベルト・ボッシュ・ゲゼルシャフト・ミト・ベシュレンクテル・ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ | Transmitter for transmitting light |
| US11249192B2 (en) | 2016-11-30 | 2022-02-15 | Blackmore Sensors & Analytics, Llc | Method and system for automatic real-time adaptive scanning with optical ranging systems |
| US11366228B2 (en) | 2017-07-10 | 2022-06-21 | Blackmore Sensors & Analytics, Llc | Method and system for time separated quadrature detection of doppler effects in optical range measurements |
| US11500106B2 (en) | 2018-04-23 | 2022-11-15 | Blackmore Sensors & Analytics, Llc | LIDAR system for autonomous vehicle |
| US11537808B2 (en) | 2016-11-29 | 2022-12-27 | Blackmore Sensors & Analytics, Llc | Method and system for classification of an object in a point cloud data set |
| US11585925B2 (en) | 2017-02-03 | 2023-02-21 | Blackmore Sensors & Analytics, Llc | LIDAR system to adjust doppler effects |
| US11624828B2 (en) | 2016-11-30 | 2023-04-11 | Blackmore Sensors & Analytics, Llc | Method and system for adaptive scanning with optical ranging systems |
| US11822010B2 (en) | 2019-01-04 | 2023-11-21 | Blackmore Sensors & Analytics, Llc | LIDAR system |
| US12130363B2 (en) | 2022-02-03 | 2024-10-29 | Aurora Operations, Inc. | LIDAR system |
-
1986
- 1986-09-16 JP JP21741986A patent/JPS6371674A/en active Pending
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1082858A (en) * | 1996-07-15 | 1998-03-31 | Hiromasa Ito | Optical range finder |
| JP2006513399A (en) * | 2002-05-29 | 2006-04-20 | ケント・エル・デインズ | System and method for measuring velocity using frequency modulation of laser power |
| JP2014202716A (en) * | 2013-04-09 | 2014-10-27 | 株式会社日立ハイテクノロジーズ | Distance measuring device |
| US11921210B2 (en) | 2016-11-29 | 2024-03-05 | Aurora Operations, Inc. | Method and system for classification of an object in a point cloud data set |
| US11537808B2 (en) | 2016-11-29 | 2022-12-27 | Blackmore Sensors & Analytics, Llc | Method and system for classification of an object in a point cloud data set |
| JP2019537012A (en) * | 2016-11-30 | 2019-12-19 | ブラックモア センサーズ アンド アナリティクス インク． | Method and system for Doppler correction of Doppler detection and optical chirp distance detection |
| US11249192B2 (en) | 2016-11-30 | 2022-02-15 | Blackmore Sensors & Analytics, Llc | Method and system for automatic real-time adaptive scanning with optical ranging systems |
| KR20210059021A (en) * | 2016-11-30 | 2021-05-24 | 블랙모어 센서스 앤드 애널리틱스, 엘엘씨 | Method and system for doppler detection and doppler correction of optical chirped range detection |
| US11874375B2 (en) | 2016-11-30 | 2024-01-16 | Blackmore Sensors & Analytics, LLC. | Method and system for automatic real-time adaptive scanning with optical ranging systems |
| US11624828B2 (en) | 2016-11-30 | 2023-04-11 | Blackmore Sensors & Analytics, Llc | Method and system for adaptive scanning with optical ranging systems |
| US11802965B2 (en) | 2016-11-30 | 2023-10-31 | Blackmore Sensors & Analytics Llc | Method and system for doppler detection and doppler correction of optical chirped range detection |
| US11585925B2 (en) | 2017-02-03 | 2023-02-21 | Blackmore Sensors & Analytics, Llc | LIDAR system to adjust doppler effects |
| US11366228B2 (en) | 2017-07-10 | 2022-06-21 | Blackmore Sensors & Analytics, Llc | Method and system for time separated quadrature detection of doppler effects in optical range measurements |
| JP2021510834A (en) * | 2018-01-16 | 2021-04-30 | ロベルト・ボッシュ・ゲゼルシャフト・ミト・ベシュレンクテル・ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ | Transmitter for transmitting light |
| US11500106B2 (en) | 2018-04-23 | 2022-11-15 | Blackmore Sensors & Analytics, Llc | LIDAR system for autonomous vehicle |
| US11947017B2 (en) | 2018-04-23 | 2024-04-02 | Aurora Operations, Inc. | Lidar system for autonomous vehicle |
| US11822010B2 (en) | 2019-01-04 | 2023-11-21 | Blackmore Sensors & Analytics, Llc | LIDAR system |
| US12130363B2 (en) | 2022-02-03 | 2024-10-29 | Aurora Operations, Inc. | LIDAR system |
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