JP2515136B2 - Reflective photoelectric detector - Google Patents
Reflective photoelectric detectorInfo
- Publication number
- JP2515136B2 JP2515136B2 JP63104266A JP10426688A JP2515136B2 JP 2515136 B2 JP2515136 B2 JP 2515136B2 JP 63104266 A JP63104266 A JP 63104266A JP 10426688 A JP10426688 A JP 10426688A JP 2515136 B2 JP2515136 B2 JP 2515136B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- light emitting
- light
- random number
- frequency
- 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
- 238000001514 detection method Methods 0.000 claims description 12
- 230000001360 synchronised effect Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 claims 1
- 230000003287 optical effect Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 3
- 230000007257 malfunction Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
- G01S17/931—Lidar systems specially adapted for specific applications for anti-collision purposes of land vehicles
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Description
【発明の詳細な説明】 ［発明の対象技術分野］ この発明は反射形の光電検出装置に係り、たとえば自
動搬送車の衝突防止用のセンサーとして用いられる。Description: TECHNICAL FIELD The present invention relates to a reflection type photoelectric detection device, and is used as a sensor for collision prevention of an automatic guided vehicle, for example.
［従来技術］ 従来この種の反射形光電検出装置を衝突防止用のセン
サーとして用いるばあい、他のセンサーからの光により
誤動作を起こすことがある。これを解決するため１つの
センサー内に発光周期すなわち発光周波数の異なる複数
の状態を有し、その中の１つをあらかじめ選択して使用
し、相互干渉が起こらないようにしている。[Prior Art] Conventionally, when this type of reflection-type photoelectric detection device is used as a sensor for collision prevention, a malfunction may occur due to light from other sensors. In order to solve this, one sensor has a plurality of states with different light emission periods, that is, light emission frequencies, and one of them is selected in advance and used to prevent mutual interference.
［この発明が解決しようとする問題点］ 従来の装置においては同一場所で使用できる数がその
装置すなわちセンサーの有する発光周波数の数で限定さ
れる。また発光周波数が固定されているために複数のセ
ンサーを使用するばあい、それぞれ発光周波数の異なる
ものを用いなければならず、したがって使用するセンサ
ーの数だけ周波数の種類を必要とする。[Problems to be Solved by the Invention] In the conventional device, the number of devices that can be used at the same place is limited by the number of emission frequencies of the device, that is, the sensor. Further, when a plurality of sensors are used because the light emission frequency is fixed, the ones having different light emission frequencies must be used, so that the number of kinds of frequencies is required for the number of sensors used.
［発明の目的］ この発明はこのような従来の欠点にかんがみ、光電検
出装置の保有する周波数の数による装置の使用台数の制
限を解消することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object thereof is to eliminate the limitation of the number of devices used by the number of frequencies possessed by the photoelectric detection device.
［発明の構成］ そこでこの発明は１つの光電検出装置内に複数の発光
周波数を保有するとともに、各周波数を任意に選択する
ために、乱数発生回路を設けたものである。[Configuration of Invention] Therefore, the present invention has a plurality of light emission frequencies in one photoelectric detection device, and a random number generation circuit is provided to arbitrarily select each frequency.
［発明の作用］ 乱数発生回路からの乱数信号によりある種の発光周波
数を選択し、これがオンレベルに達した後、一定時間毎
にその発光周波数を任意に、かつ自動的に複数回切り換
え、引き続き各周波数でオンレベルにあるときのみ出力
動作をする。[Operation of the Invention] A certain light emission frequency is selected by the random number signal from the random number generation circuit, and after the light emission frequency reaches the on level, the light emission frequency is arbitrarily and automatically switched a plurality of times at regular time intervals. The output operation is performed only when it is on level at each frequency.
［実施例］ 以下図によってこの発明の一実施例について説明す
る。[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.
すなわち第１図において発光回路１は発光素子３を有
し、その内部には複数個の発光周波数を発生する周波数
発生回路や、後述する乱数発生回路からの信号に応じ
て、発光素子３を選択された１つの発光周波数により駆
動する制御回路を有する。また受光回路２は受光素子４
を有し、その出力端には増幅回路５が接続される。この
増幅回路の出力端にはレベル弁別回路６、信号処理回路
７および出力回路８が順次接続される。また乱数発生回
路９は発光回路１および信号処理回路７に接続される。
さらに発光回路１およびレベル弁別回路６には同期回路
10が接続される。That is, in FIG. 1, the light emitting circuit 1 has a light emitting element 3, and the light emitting element 3 is selected in accordance with signals from a frequency generating circuit that generates a plurality of light emitting frequencies and a random number generating circuit described later. It has a control circuit which is driven by one selected emission frequency. The light receiving circuit 2 is a light receiving element 4
And an amplifier circuit 5 is connected to the output terminal thereof. The level discrimination circuit 6, the signal processing circuit 7, and the output circuit 8 are sequentially connected to the output terminal of the amplifier circuit. The random number generation circuit 9 is connected to the light emitting circuit 1 and the signal processing circuit 7.
Further, the light emitting circuit 1 and the level discriminating circuit 6 include a synchronizing circuit.
10 are connected.
そして乱数発生回路９は乱数を発生する機能と、その
乱数に基づいて発光回路１が有する複数の発光周波数の
中の１つを任意に選択する周波数選択機能と、所定の周
期をもって乱数すなわち発光回路１の発光周波数を変化
させる機能を有している。これによって発光素子３が選
択された周波数によって、かつ所定の周期をもって発光
する。この関係を第２図を参照して説明する。The random number generating circuit 9 has a function of generating a random number, a frequency selecting function of arbitrarily selecting one of a plurality of light emitting frequencies of the light emitting circuit 1 based on the random number, and a random number, that is, a light emitting circuit with a predetermined cycle. 1 has a function of changing the light emission frequency. As a result, the light emitting element 3 emits light at the selected frequency and at a predetermined cycle. This relationship will be described with reference to FIG.
すなわちこの図において、今乱数発生回路９が乱数
Ａ、Ｂ、Ｃ、Ｄを発生するものとする。そしてその乱数
の発生順序がＢ、Ｄ、Ｃ、Ａ、Ｄであるとする。する
と、乱数発生回路９の制御機能はその乱数に対応した発
光周波数を選択する。たとえばその乱数がＢであるとす
ると、これに対応した発光回路１の発光周波数f2が選ば
れ、その制御回路により発光素子３は周波数f2をもって
発光する。そしてその周波数は所定の周期ｔだけ継続す
る。That is, in this figure, it is assumed that the random number generation circuit 9 now generates random numbers A, B, C, and D. It is assumed that the random numbers are generated in the order of B, D, C, A, and D. Then, the control function of the random number generation circuit 9 selects the light emission frequency corresponding to the random number. For example, if the random number is B, the light emission frequency f2 of the light emitting circuit 1 corresponding to this is selected, and the light emitting element 3 emits light at the frequency f2 by the control circuit. Then, the frequency continues for a predetermined period t.
さらに周期ｔの経過後、新たに乱数Ｄが発生すると、
乱数発生回路９の制御機能により、その乱数Ｄに対応す
る発光周波数f4が選択され、これによって発光素子３は
所定の周期ｔをもって発光する。Further, when a new random number D is generated after the lapse of the cycle t,
The light emission frequency f4 corresponding to the random number D is selected by the control function of the random number generation circuit 9, whereby the light emitting element 3 emits light at a predetermined cycle t.
以下乱数Ｃ、Ａ、Ｄと順に発生することにより乱数発
生回路９発光回路１の有する発光周波数f3、f1、f4をそ
れぞれ選択する。したがってこれに対応して発光素子３
はそれぞれの発光周波数をもって、かつ所定の周期ｔを
もって発光する。The light emitting frequencies f3, f1 and f4 of the light emitting circuit 1 are selected by sequentially generating random numbers C, A and D, respectively. Therefore, in response to this, the light emitting element 3
Emits light at each emission frequency and at a predetermined cycle t.
発光素子３から出た光は被検出物体11に照射され、さ
らにここで反射された光は受光素子４に入射する。この
受光素子に流れる電流は受光回路２によって電圧に変換
され、さらに増幅回路５によって増幅される。そしてこ
の出力は同期回路10によって発光回路１と同期をとった
後レベル弁別回路６に入力され、そのレベルが所定の値
に達するとその出力は信号処理回路７に供給される。こ
こでそのレベルが一定時間以上、所定の値以上であった
ばあい、信号処理回路７より乱数発生回路９に信号が伝
わり、新たな乱数が発生し、発光回路に１により新たな
周波数が選択され、発光素子３が発光する。このループ
をあらかじめ定めた回数だけ繰り返すと、信号処理回路
７より出力回路８に信号が伝わり、装置としての出力が
得られる。The light emitted from the light emitting element 3 is applied to the object 11 to be detected, and the light reflected here is incident on the light receiving element 4. The current flowing through the light receiving element is converted into a voltage by the light receiving circuit 2 and further amplified by the amplifier circuit 5. Then, this output is input to the level discriminating circuit 6 after being synchronized with the light emitting circuit 1 by the synchronizing circuit 10, and when the level reaches a predetermined value, its output is supplied to the signal processing circuit 7. If the level is a predetermined value or more for a certain time or more, a signal is transmitted from the signal processing circuit 7 to the random number generation circuit 9, a new random number is generated, and a new frequency is selected by 1 in the light emitting circuit. Then, the light emitting element 3 emits light. When this loop is repeated a predetermined number of times, a signal is transmitted from the signal processing circuit 7 to the output circuit 8 and an output as a device is obtained.
第３図は乱数発生回路９による発光回路１の発光周波
数の切り換え回数ｒを２回すなわちｒ＝２としたばあい
のタイミングチャートである。FIG. 3 is a timing chart when the number of times r the light emitting frequency of the light emitting circuit 1 is switched by the random number generating circuit 9 is two, that is, r = 2.
まず発光回路１はこれが保有している複数すなわちＮ
個の発光周波数の中から１つが乱数発生回路９により発
生した乱数に応じて選択され、これによって発光素子３
が発光している。この発光周波数は被検出物体11からの
反射光の中、その周波数と等しい周波数の光が受光素子
４に入射しない限り、その発光周波数は維持される。First, the light emitting circuit 1 has a plurality of N, that is, N
One of the light emission frequencies is selected according to the random number generated by the random number generation circuit 9, whereby the light emitting element 3 is selected.
Is emitting light. This emission frequency is maintained as long as the reflected light from the object to be detected 11 has no light having a frequency equal to that frequency, which is incident on the light receiving element 4.
そして同図の時点Ａで被検出物体11が検出装置の感応
領域内に入ると、すなわち同周波数の光が受光素子４に
入射するとレベル弁別回路６の出力はＨレベルとなる。
なおこの出力は検出装置全体としては中間出力となる。When the object 11 to be detected enters the sensitive region of the detection device at time A in the figure, that is, when light of the same frequency enters the light receiving element 4, the output of the level discrimination circuit 6 becomes H level.
This output is an intermediate output for the entire detection device.
このとき中間出力がＨレベルになり時間ｔが経過した
時点で乱数発生回路９により発生した乱数に応じて発光
回路１が有するＮ個の発光周波数の中から任意の周波数
すなわち第２番目の発光周波数を選択する。このとき被
検出物体11が検出装置の感応領域内にあればその発光周
波数における中間出力はＨレベルである。そしてこのＨ
レベルの状態でさらに時間ｔが経過すると発光回路の発
光周波数は第３番目の周波数に切り換わる。それでもな
おその発光周波数における中間出力がＨレベルで、かつ
所定の時間ｔを経過すると信号処理回路７を通して出力
回路８より検出装置としての出力すなわちオン状態の出
力を出す。At this time, when the intermediate output becomes H level and the time t elapses, an arbitrary frequency, that is, the second light emission frequency, from the N light emission frequencies of the light emission circuit 1 according to the random number generated by the random number generation circuit 9. Select. At this time, if the detected object 11 is within the sensitive area of the detection device, the intermediate output at the light emission frequency is H level. And this H
When the time t further elapses in the level state, the light emission frequency of the light emitting circuit switches to the third frequency. Nevertheless, when the intermediate output at the light emission frequency is H level and a predetermined time t has elapsed, the output as the detection device, that is, the on-state output is output from the output circuit 8 through the signal processing circuit 7.
そして検出装置がオン状態になった後も引き続き時間
ｔ毎に乱数発生回路９により発生した乱数に応じて発光
回路１の発光周波数を任意に切り換える。Then, even after the detecting device is turned on, the light emission frequency of the light emitting circuit 1 is arbitrarily switched according to the random number generated by the random number generating circuit 9 every time t.
そしてある点たとえば第３図のＢ点すなわちｋ番目の
周波数で被検出物体11がなくなるとｋ＋１番目の周波数
での中間出力がＬレベルとなり、この状態が時間ｔ′継
続したばあい出力回路８の出力はオフとなる。Then, at a certain point, for example, point B in FIG. 3, that is, when the detected object 11 disappears at the k-th frequency, the intermediate output at the k + 1-th frequency becomes L level, and if this state continues for time t ', the output circuit 8 The output turns off.
なお時間ｔ′は時間ｔと同じに設定してもよい。 The time t ′ may be set to be the same as the time t.
［発明の効果］ この発明は上述のように発光回路１が複数の発光周波
数を有し、この発光周波数を乱数発生回路９により発生
した乱数に応じて１つずつ任意に選択して発光回路１の
発光周波数を変化させると同時に受光回路２により受信
された光信号を上記発光周波数の変化にあわせて処理す
るようにしているので、複数個の光電検出装置を併設す
るばあいにも相互干渉の起こる確立を低下させることが
でき、したがって光電検出装置の配設個数が制約を受け
ることがない。EFFECTS OF THE INVENTION In the present invention, as described above, the light emitting circuit 1 has a plurality of light emitting frequencies, and the light emitting circuit 1 is arbitrarily selected one by one according to the random number generated by the random number generating circuit 9. The light signal received by the light receiving circuit 2 is processed at the same time that the light emission frequency of the light receiving circuit 2 is changed according to the change of the light emitting frequency. The probability of occurring can be reduced, so that the number of arranged photoelectric detection devices is not restricted.
すなわち発光回路１の発光周波数の数をＮ、乱数発生
回路９による発光種は数の切り換え回数をｒとすると相
互干渉の起こる確立は1/Nr+1で表される。That is, assuming that the number of light emission frequencies of the light emitting circuit 1 is N and the number of light emission species by the random number generating circuit 9 is r, the probability of mutual interference is represented by 1 / N r + 1 .
したがって発光周波数の数Ｎを多くすることができな
いばあいには切り換え回数ｒを増加すればよい。この関
係は任意の２つの光電検出装置間でつねに成り立つので
その装置の数による影響を全く受けない。ちなみに発光
周波数の数Ｎを10、切り換え回数ｒを４としたばあいの
誤動作の確立は1/105＝0.01％である。Therefore, if the number N of light emission frequencies cannot be increased, the number of switching times r may be increased. This relationship is always established between any two photoelectric detection devices and is therefore completely unaffected by the number of devices. By the way, if the number N of emission frequencies is 10 and the number of switching times r is 4, the probability of malfunction is 1/10 5 = 0.01%.
第１図はこの発明における光電検出装置の一実施例を示
すブッロック回路図、第２図は第１図において、乱数発
生回路によって発生する乱数と発光回路が有する発光周
波数との関係およびその周期を説明する説明図、第３図
は第１図における動作を説明するタイミング図である。 １……発光回路 ２……受光回路 ３……発光素子 ４……受光素子 ５……増幅回路 ６……レベル弁別回路 ７……信号処理回路 ８……出力回路 ９……乱数発生回路 10……同期回路 11……被検出物体FIG. 1 is a block diagram showing a photoelectric detection device according to an embodiment of the present invention, and FIG. 2 shows the relationship between the random number generated by the random number generation circuit and the light emission frequency of the light emission circuit and its cycle. FIG. 3 is an explanatory diagram for explaining, and FIG. 3 is a timing diagram for explaining the operation in FIG. 1 ... Light emitting circuit 2 ... Light receiving circuit 3 ... Light emitting element 4 ... Light receiving element 5 ... Amplifying circuit 6 ... Level discriminating circuit 7 ... Signal processing circuit 8 ... Output circuit 9 ... Random number generating circuit 10 ... … Synchronizing circuit 11 …… Detected object
Claims (1)
と、この発光回路（１）から投射され、かつ被検出物体
（11）によって反射された光を受信する受光回路（２）
と、上記発光回路（１）の各発光周波数に対応する乱数
を発生するとともに、上記発光回路（１）の発光周波数
の中、任意の発光周波数を１つずつ選択する機能および
所定の周期をもって上記発光周波数を変化させる機能を
有する乱数発生回路（９）と、上記発光回路（１）の出
力と上記受光回路（２）の受光出力との同期をとる同期
回路（10）と、この同期回路（10）によって同期をとっ
た上記受光回路（２）の受光出力を処理する信号処理回
路（７）およびこの信号処理回路（７）によって処理さ
れた信号を出力する出力回路（８）とを備え、上記乱数
発生回路（９）により発生した乱数に対応して上記発光
回路（１）の発光周波数の１つを選択するとともに、こ
の発光周波数を一定時間毎に変化させ、さらに上記受光
回路（２）により受信された光信号を上記発光周波数の
周期毎の変化に合わせて処理し、かつ出力することを特
徴とする反射形光電検出装置。1. A light emitting circuit (1) having a plurality of light emitting frequencies.
And a light receiving circuit (2) for receiving the light projected from the light emitting circuit (1) and reflected by the object to be detected (11)
And a function of generating a random number corresponding to each light emitting frequency of the light emitting circuit (1) and selecting one of the light emitting frequencies of the light emitting circuit (1) one by one and having a predetermined cycle. A random number generating circuit (9) having a function of changing the light emission frequency, a synchronizing circuit (10) for synchronizing the output of the light emitting circuit (1) and the light receiving output of the light receiving circuit (2), and this synchronizing circuit ( A signal processing circuit (7) for processing the light receiving output of the light receiving circuit (2) synchronized by 10) and an output circuit (8) for outputting the signal processed by the signal processing circuit (7), One of the light emitting frequencies of the light emitting circuit (1) is selected according to the random number generated by the random number generating circuit (9), and the light emitting frequency is changed at regular intervals, and the light receiving circuit (2) is further selected. Received by A reflection type photoelectric detection device, which processes and outputs the received optical signal in accordance with the change of the emission frequency in each cycle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63104266A JP2515136B2 (en) | 1988-04-28 | 1988-04-28 | Reflective photoelectric detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63104266A JP2515136B2 (en) | 1988-04-28 | 1988-04-28 | Reflective photoelectric detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01276086A JPH01276086A (en) | 1989-11-06 |
| JP2515136B2 true JP2515136B2 (en) | 1996-07-10 |
Family
ID=14376126
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63104266A Expired - Fee Related JP2515136B2 (en) | 1988-04-28 | 1988-04-28 | Reflective photoelectric detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2515136B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4577577B2 (en) * | 2006-03-28 | 2010-11-10 | ソニー株式会社 | Optical communication system |
| JP2019158894A (en) * | 2019-05-31 | 2019-09-19 | 株式会社デンソー | Laser radar device and surroundings monitoring system |
-
1988
- 1988-04-28 JP JP63104266A patent/JP2515136B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01276086A (en) | 1989-11-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |