JPH0778534B2 - Distance measurement method using lightwave rangefinder - Google Patents
Distance measurement method using lightwave rangefinderInfo
- Publication number
- JPH0778534B2 JPH0778534B2 JP61255842A JP25584286A JPH0778534B2 JP H0778534 B2 JPH0778534 B2 JP H0778534B2 JP 61255842 A JP61255842 A JP 61255842A JP 25584286 A JP25584286 A JP 25584286A JP H0778534 B2 JPH0778534 B2 JP H0778534B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- receiving element
- output
- distance
- light source
- 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 - Fee Related
Links
Landscapes
- Optical Radar Systems And Details Thereof (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、光波距離計を用いる測距方法に関する。Description: TECHNICAL FIELD The present invention relates to a distance measuring method using a light wave distance meter.
（従来の技術） 従来、光源に対設したモニタ用受光素子の出力を帰還し
て光源の発光量の自動制御を行ない、光源からの送信光
が目標物で反射した反射光と参照光とを交互に測距用受
光素子に入力させ、該受光素子から出力した反射光に対
応する受信信号と参照光に対応する参照信号との位相差
から目標物までの距離を測定する光波距離計による測距
方法は知られている。(Prior Art) Conventionally, the output of a light receiving element for monitoring installed opposite to a light source is fed back to automatically control the amount of light emitted from the light source, and the transmitted light from the light source is reflected by a target object and the reflected light and the reference light. An optical distance meter is used to measure the distance to the target from the phase difference between the received signal corresponding to the reflected light output from the light receiving element and the reference signal corresponding to the reference light. Distance methods are known.
第２図は、該光波距離計における光源の発光量の自動制
御回路を示す。FIG. 2 shows an automatic control circuit of the light emission amount of the light source in the light distance meter.
図において、（１）は例えばレーザダイオードから成る
光源で、該光源（１）に対設されたモニタ用受光素子
（２）の出力は増幅器（３）で増幅されて差動増幅器
（４）に入力する。該差動増幅器（４）は該入力とボリ
ュームで設定された設定値との差信号を出力し、該差信
号で光源（１）と電源（10）との間に介入されたトラン
ジスタ（11）のインピーダンスを変え、光源（１）の発
光量を自動制御し、周囲温度及び自己発熱による光源の
発光量の変化を防止している。尚、（12）は変調信号入
力端子、（13）はトランジスタ作動開始時の駆動電流を
抑制するためのスロースタート回路である。In the figure, (1) is a light source composed of, for example, a laser diode, and the output of a monitor light receiving element (2) provided in opposition to the light source (1) is amplified by an amplifier (3) to a differential amplifier (4). input. The differential amplifier (4) outputs a difference signal between the input and a set value set by the volume, and the transistor (11) interposed between the light source (1) and the power supply (10) by the difference signal. Of the light source (1) is automatically controlled to prevent changes in the light emission amount of the light source due to ambient temperature and self-heating. Incidentally, (12) is a modulation signal input terminal, and (13) is a slow start circuit for suppressing the drive current at the start of the transistor operation.
（発明が解決しようとする問題点） 上述した光波距離計における光源の発光量の自動制御回
路によれば、光源からの送信光が目標物で反射した反射
光を測距用受光素子に入力させた時、外界からの各種の
光が光源例えばレーザダイオードに入力し易い。したが
って、該レーザダイオードのバイアス点がふらつき、見
掛上そのインピーダンスが変動するので、該自動制御回
路の作動が不安定となる。その結果、測距用受光素子か
ら出力した反射光に対応する受信信号と参照光に対応す
る参照信号との間に測量上好ましくない位相差つまり、
目標物までの距離に対応する位相差からの位相変動分が
入り込み、測距値の精確度が不安定となるという不都合
を生ずる。(Problems to be Solved by the Invention) According to the above-described automatic control circuit of the light emission amount of the light source in the optical distance meter, the reflected light obtained by reflecting the transmitted light from the light source on the target object is input to the distance measuring light receiving element. At this time, various kinds of light from the outside are easily input to the light source, for example, the laser diode. Therefore, the bias point of the laser diode fluctuates and its impedance fluctuates apparently, so that the operation of the automatic control circuit becomes unstable. As a result, a phase difference that is not preferable in surveying between the received signal corresponding to the reflected light output from the distance measuring light receiving element and the reference signal corresponding to the reference light, that is,
A phase variation amount from the phase difference corresponding to the distance to the target object is introduced, which causes an inconvenience that the accuracy of the distance measurement value becomes unstable.
本発明は、従来のこのような不都合を解消する光波距離
計による測距方法を提供することをその目的とするもの
である。SUMMARY OF THE INVENTION It is an object of the present invention to provide a distance measuring method using a lightwave distance meter that solves the conventional inconvenience.
（問題点を解決するための手段） 本発明は、上記の目的を達成するために、光源に対設し
たモニタ用受光素子の出力を帰還して光源の発光量の自
動制御を行ない、光源からの送信光が目標物で反射した
反射光と参照光とを交互に測距用受光素子に入力させ、
該受光素子から出力した反射光に対応する受信信号と参
照光に対応する参照信号との位相差から目標物までの距
離を測定する光波距離計による測距方法において、参照
光を測距用受光素子に入力させた時のモニタ用受光素子
の出力をサンプルホールドし、この出力を帰還して光源
の発光量を制御しながら測距を行うことを特徴とする。(Means for Solving Problems) In order to achieve the above-mentioned object, the present invention feeds back an output of a monitor light-receiving element opposite to a light source to automatically control the light emission amount of the light source. The reflected light reflected by the target object and the reference light are alternately input to the distance measuring light receiving element,
In a distance measuring method using an optical wave range finder for measuring a distance to a target from a phase difference between a reception signal corresponding to reflected light output from the light receiving element and a reference signal corresponding to reference light, the reference light is received for distance measurement. It is characterized in that the output of the monitor light receiving element when it is input to the element is sampled and held, and the output is fed back to measure the distance while controlling the light emission amount of the light source.
（実施例） 本発明の実施例を添付図面につき説明する。(Embodiment) An embodiment of the present invention will be described with reference to the accompanying drawings.
第１図は、本発明の実施に使用する光波距離計における
光源の発光量の制御回路を示す。FIG. 1 shows a control circuit for controlling the amount of light emitted from a light source in a lightwave rangefinder used for implementing the present invention.
図中（１）は光源例えばレーザダイオードで、該レーザ
ダイオード（１）に対向してモニタ用受光素子としての
モニタ用ホトダイオード（２）が従来例と同様に配設さ
れている。該モニタ用ホトダイオード（２）の出力は増
幅器（３）で増幅されて差動増幅器（４）に入力され、
該差動増幅器（４）はサンプルホールド回路（５）に接
続され、該サンプルホールド回路（５）の出力は、スイ
ッチ（６）を介してレーザダイオード（１）のバイアス
を所定値に設定する可変抵抗（７）に接続された電圧分
割抵抗(81)(82)の中間接続点に接続されている。該可変
抵抗（７）と電圧分割抵抗(81)との接続点は、インピー
ダンス調整用バッファ（９）を経て、レーザダイオード
（１）と電源（10）との間に接続されたトランジスタ
（11）の制御極に接続されている。In the figure, (1) is a light source such as a laser diode, and a monitoring photodiode (2) as a light receiving element for monitoring is arranged facing the laser diode (1) in the same manner as in the conventional example. The output of the monitoring photodiode (2) is amplified by the amplifier (3) and input to the differential amplifier (4),
The differential amplifier (4) is connected to a sample and hold circuit (5), and the output of the sample and hold circuit (5) is variable to set the bias of the laser diode (1) to a predetermined value via a switch (6). It is connected to the intermediate connection point of the voltage dividing resistors (8 1 ) and (8 2 ) connected to the resistor (7). Variable resistor (7) and the voltage dividing resistor (81) and the connection point, through the impedance adjusting buffer (9), a transistor connected between the laser diode (1) and the power supply (10) (11 ) Is connected to the control pole.
尚、図中、（12）及び（13）はそれぞれ変調信号入力端
子及びスロースタート回路である。In the figure, (12) and (13) are a modulation signal input terminal and a slow start circuit, respectively.
上述の制御回路以外の光波距離計の構成は従来のものと
特に異ならない。すなわち、光源からの送信光が目標物
で反射した反射光と参照光とを交互に測距用受光素子に
入力させ、該受光素子から出力した反射光に対応する受
信信号と参照光に対応する参照信号との位相差から目標
物までの距離を測定するように構成されている。The configuration of the lightwave rangefinder other than the control circuit described above is not particularly different from the conventional one. That is, the transmitted light from the light source alternately receives the reflected light reflected by the target object and the reference light, and the reflected light and the reference light corresponding to the reflected light output from the light receiving element are input to the distance measuring light receiving element. It is configured to measure the distance to the target from the phase difference from the reference signal.
次に本発明による測距方法について説明する。Next, the distance measuring method according to the present invention will be described.
測距の先立って第１図示の制御回路のスイッチ（６）を
開成し、ボリューム（14）を調整して差動増幅器（４）
の両入力端子を同電位にした後、該スイッチ（６）を閉
成しておく。Prior to the distance measurement, the switch (6) of the control circuit shown in FIG. 1 is opened and the volume (14) is adjusted to adjust the differential amplifier (4).
After setting both input terminals to the same potential, the switch (6) is closed.
測距する時は、外界からの各種の光の影響を受けない、
参照光を測距用受光素子に入力する時に、サンプルホー
ルド回路（５）にサンプリングパルスを加え、増幅器
（３）及び差動増幅器（４）で増幅したモニタ用ホトダ
イオード（２）の出力をサンプルホールドする。かくて
トランジスタ（11）は、サンプリングされたモニタ用ホ
トダイオード（４）の出力に応じたインピーダンス値と
なり、それに応じてレーザダイオード（１）のバイアス
点は、参照光を測距用受光素子に入力させている時及び
反射光を測距用受光素子に入力させている時にある値に
固定され、該レーザーダイオード（１）の電気的インピ
ーダンスは固定される。When measuring distance, it is not affected by various light from the outside world,
When the reference light is input to the light receiving element for distance measurement, a sampling pulse is applied to the sample and hold circuit (5) to sample and hold the output of the monitoring photodiode (2) amplified by the amplifier (3) and the differential amplifier (4). To do. Thus, the transistor (11) has an impedance value according to the sampled output of the monitoring photodiode (4), and accordingly, the bias point of the laser diode (1) causes the reference light to be input to the distance measuring light receiving element. The laser diode (1) is fixed to a certain value while the reflected light is input to the distance measuring light receiving element, and the electric impedance of the laser diode (1) is fixed.
したがって測距用受光素子から出力した反射光に対応す
る受信信号と参照光に対応する参照信号との間の測量上
好ましくない位相差つまり目標物までの距離に対応する
位相差からの位相変動分が除去される。Therefore, a phase difference that is not preferable in surveying between the received signal corresponding to the reflected light output from the distance measuring light receiving element and the reference signal corresponding to the reference light, that is, the phase fluctuation amount from the phase difference corresponding to the distance to the target object. Are removed.
以上のようなモニタ用ホトダイオード（２）の出力のサ
ンプルホールドを測距の度に行なえば、レーザダイオー
ド（１）のしきい値が周囲温度及び自己発熱により緩か
に変化しても該レーザダイオード（２）の発光量は一定
に保たれる。If the output of the monitoring photodiode (2) is sampled and held every time the distance is measured, the laser diode (1) can be slowly changed due to ambient temperature and self-heating. The light emission amount of (2) is kept constant.
（発明の効果） 以上説明したように、本発明によるときは、参照光を測
距用受光素子に入力させた時のモニタ用受光素子の出力
をサンプルホールドし、この出力を帰還して光源の発光
量を制御しながら測距を行なうようにしたから、外界の
各種の光が光源に入力しても有効に高精度の測距を期待
できる効果を有する。(Effects of the Invention) As described above, according to the present invention, the output of the monitor light receiving element when the reference light is input to the distance measuring light receiving element is sampled and held, and this output is fed back to the light source of the light source. Since distance measurement is performed while controlling the amount of light emission, there is an effect that even if various kinds of light in the external world are input to the light source, effective distance measurement with high accuracy can be expected.
第１図は本発明の実施に使用する光波測距計における光
源の光量制御回路の結線図、第２図は従来の光源の光量
制御回路の結線図である。 （１）…レーザダイオード （２）…モニタ用ホトダイオード （４）…サンプルホールド回路 （11）…トランジスタFIG. 1 is a wiring diagram of a light amount control circuit of a light source in a light wave range finder used for implementing the present invention, and FIG. 2 is a wiring diagram of a conventional light amount control circuit of a light source. (1) ... laser diode (2) ... monitoring photodiode (4) ... sample and hold circuit (11) ... transistor
Claims (1)
帰還して光源の発光量の自動制御を行ない、光源からの
送信光が目標物で反射した反射光と参照光とを交互に測
距用受光素子に入力させ、該受光素子から出力した反射
光に対応する受信信号と参照光に対応する参照信号との
位相差から目標物までの距離を測定する光波距離計によ
る測距方法において、参照光を測距用受光素子に入力さ
せた時のモニタ用受光素子の出力をサンプルホールド
し、この出力を帰還して光源の発光量を制御しながら測
距を行なうことを特徴とする光波距離計による測距方
法。1. The output of a light receiving element for monitoring provided opposite to a light source is fed back to automatically control the amount of light emitted from the light source, and the transmitted light from the light source is alternately reflected light reflected by a target and reference light. A distance measuring method using a light-wave rangefinder that measures the distance to a target from the phase difference between the received signal corresponding to the reflected light output from the light receiving element and the reference signal corresponding to the reference light, which is input to the distance measuring light receiving element. In (1), the output of the monitor light receiving element when the reference light is input to the distance measuring light receiving element is sampled and held, and the output is fed back to perform the distance measurement while controlling the light emission amount of the light source. Distance measurement method using lightwave rangefinder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61255842A JPH0778534B2 (en) | 1986-10-29 | 1986-10-29 | Distance measurement method using lightwave rangefinder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61255842A JPH0778534B2 (en) | 1986-10-29 | 1986-10-29 | Distance measurement method using lightwave rangefinder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63111488A JPS63111488A (en) | 1988-05-16 |
| JPH0778534B2 true JPH0778534B2 (en) | 1995-08-23 |
Family
ID=17284348
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61255842A Expired - Fee Related JPH0778534B2 (en) | 1986-10-29 | 1986-10-29 | Distance measurement method using lightwave rangefinder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0778534B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6604623B2 (en) * | 2015-03-31 | 2019-11-13 | 株式会社トプコン | Light wave distance meter |
| WO2019146440A1 (en) * | 2018-01-23 | 2019-08-01 | 日本電産株式会社 | Distance measurement device, and mobile body |
-
1986
- 1986-10-29 JP JP61255842A patent/JPH0778534B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63111488A (en) | 1988-05-16 |
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