JP4170925B2

JP4170925B2 - Multi-optical axis photoelectric sensor and collision prevention sensor

Info

Publication number: JP4170925B2
Application number: JP2004024916A
Authority: JP
Inventors: 二朗神谷; 直昭野田
Original assignee: サンクス株式会社
Priority date: 2004-01-30
Filing date: 2004-01-30
Publication date: 2008-10-22
Anticipated expiration: 2024-01-30
Also published as: JP2005214904A

Description

本発明は、多光軸光電センサ及び衝突防止センサに関する。 The present invention relates to a multi-optical axis photoelectric sensor and a collision prevention sensor.

従来、例えば工場等に使用される無人搬送車には、その走行方向前方に障害物等がある場合に、その障害物等を光電センサで自動的に検出して衝突防止を図る衝突防止センサが設けられている。
ここで、一般に衝突防止センサとして機能させるには検出可能領域を広範囲にするために、多数の光電センサが並設されている。 Conventionally, for example, in an automatic guided vehicle used in a factory or the like, when there is an obstacle or the like in front of the traveling direction, there is a collision prevention sensor that automatically detects the obstacle by a photoelectric sensor and prevents collision. Is provided.
Here, in order to function as a collision prevention sensor, a large number of photoelectric sensors are arranged in parallel in order to widen the detectable region.

このものは、例えば、互いに対応する投光手段及び受光手段を、上記走行方向前方に向けて複数組横並び状に備えている。ここで、各受光手段においてそれに対応しない他の投光手段からの光が受光されると障害物の正確な検出が行えない。そこで、図１１（ａ）に示すように、複数の投光手段にそれぞれ時分割したパルスを与え、互いに異なるタイミング（Ｐ１〜Ｐ４）で順次投光させる一方、各投光手段の投光タイミングに同期してそれに対応する受光手段からの受光量に応じた受光信号を有効化し、この有効化された受光信号に基いて障害物等の検出動作を行う構成になっている。
ところで、各受光手段には、例えば照明など周囲からの外乱光（以下、干渉光）が入射する可能性がある。このような干渉光が各投光手段の投光タイミングと同時にそれに対応する受光手段に入射した場合には（図１１（ａ）参照）、この干渉光により受光量レベルが変化してしまい障害物等を正確に検出することができなくなる。 This includes, for example, a plurality of sets of light projecting means and light receiving means corresponding to each other in a side-by-side manner in the traveling direction. Here, when each light receiving means receives light from other light projecting means that does not correspond to the light receiving means, the obstacle cannot be accurately detected. Therefore, as shown in FIG. 11 (a), time-divided pulses are given to a plurality of light projecting means, and light is projected sequentially at different timings (P1 to P4), while the light projecting timing of each light projecting means is set. The light receiving signal corresponding to the amount of light received from the corresponding light receiving means is validated synchronously, and an operation of detecting an obstacle or the like is performed based on the validated light receiving signal.
By the way, disturbance light (hereinafter referred to as interference light) from the surroundings such as illumination may enter each light receiving means. When such interference light is incident on the corresponding light receiving means simultaneously with the light projection timing of each light projecting means (see FIG. 11A), the received light amount level is changed by the interference light and is an obstacle. Etc. cannot be detected accurately.

そこで、下記特許文献１には、各投光手段の投光タイミングの直前の検出タイミングでその投光手段に対応する受光手段の受光量レベルを検出し、その受光量レベルに基づき干渉光の入射の有無を検出する干渉光検出手段を備えた構成が開示されている。
特許第２６８０９７７号公報 Therefore, in Patent Document 1 below, the received light amount level of the light receiving means corresponding to the light projecting means is detected at the detection timing immediately before the light projecting timing of each light projecting means, and the incidence of interference light is based on the received light level. A configuration including interference light detection means for detecting the presence or absence of is disclosed.
Japanese Patent No. 2680977

しかしながら、上記特許文献１の構成では、干渉光が検出された場合、図１１（ｂ）に示すように、干渉光の影響を受けないタイミングまで待って、その待ち時間だけ、それ以降の全て投光手段の投光タイミングを遅らせるようになっている。従って、干渉光が検出された場合に全投光手段及び受光手段による投受光動作が終了するまでの時間が長くなり、全体として応答速度が遅くなってしまうといった問題があった。 However, in the configuration of the above-mentioned patent document 1, when interference light is detected, as shown in FIG. 11 (b), it waits until the timing at which it is not affected by the interference light, and only the waiting time is allotted thereafter. The light projection timing of the light means is delayed. Therefore, when interference light is detected, there is a problem in that the time until the light projecting / receiving operation by all the light projecting means and the light receiving means is completed becomes longer, and the response speed becomes slower as a whole.

本発明は上記のような事情に基づいて完成されたものであって、応答速度の遅れを防止しつつ干渉光による影響を排除し検出物の正確な検出が可能な多光軸光電センサ及び衝突防止センサを提供することを目的とする。 The present invention has been completed based on the above circumstances, and a multi-optical axis photoelectric sensor capable of accurately detecting a detected object by eliminating the influence of interference light while preventing a delay in response speed and collision An object is to provide a prevention sensor.

上記の目的を達成するための手段として、請求項１の発明に係る多光軸光電センサは、所定の検出領域ヘ向けて光を照射する複数の投光手段と、前記検出領域からの光を受光可能な受光手段と、
前記複数の投光手段について順次投光させるとともに、各投光手段の投光タイミングに同期して受光手段からの受光量に応じた受光信号に基づき前記検出領域内の検出物体を検出する投受光動作を行う投受光制御手段と、前記各投光手段のそれぞれの投光タイミングに対応するタイミングであって、所定の検出タイミング（例えば、投光タイミングの前の所定タイミング）毎に、前記受光手段からの受光信号に基づいて干渉光を検出する干渉光検出手段とを備えた多光軸光電センサにおいて、前記投受光制御手段は、常には、前記複数の投光手段に所定の投光タイミング毎に投受光動作を順次実行させる一方で、
前記干渉光検出手段にて干渉光が検出されたときには、その検出タイミングに対応する投光手段の投光タイミングだけを、いずれの投光手段の投光タイミングとは異なるタイミングにずらす構成としたところに特徴を有する。 As means for achieving the above object, a multi-optical axis photoelectric sensor according to the invention of claim 1 comprises a plurality of light projecting means for irradiating light toward a predetermined detection area, and light from the detection area. A light receiving means capable of receiving light;
Projecting and receiving light that sequentially projects the plurality of light projecting means and detects a detection object in the detection area based on a light reception signal corresponding to the amount of light received from the light receiving means in synchronization with the light projection timing of each light projecting means The light receiving / receiving control means for performing the operation and the timing corresponding to the light projecting timing of each of the light projecting means at each predetermined detection timing (for example, a predetermined timing before the light projecting timing). In a multi-optical axis photoelectric sensor comprising interference light detection means for detecting interference light based on a light reception signal from the light projection / reception control means, the light projection / reception control means always supplies the plurality of light projection means to a predetermined light projection timing. While executing the light emitting / receiving operation sequentially,
When interference light is detected by the interference light detection means, only the light projection timing of the light projection means corresponding to the detection timing is shifted to a timing different from the light projection timing of any light projection means. It has the characteristics.

なお、所定の検出領域ヘ向けて光を照射する複数の投光手段と、複数の投光手段のそれぞれに対応して設けられ、前記検出領域からの光を受光可能な複数の受光手段と、前記複数の投光手段について順次投光させるとともに、各投光手段の投光タイミングに同期してそれと対応する受光手段からの受光量に応じた受光信号に基づき前記検出領域内の検出物体を検出する投受光動作を行う投受光制御手段と、前記各投光手段の投光タイミング前の非投光時における検出タイミング毎に、それに対応する受光手段からの受光信号に基づいて干渉光を検出する干渉光検出手段とを備えた多光軸光電センサにおいて、前記投受光制御手段は、常には、前記複数の投光手段に所定の投光タイミング毎に投受光動作を順次実行させる一方で、前記干渉光検出手段にて干渉光が検出されたときには、その干渉光が検出された受光手段に対応する投光手段の投光動作の投光タイミングだけを、前記干渉検出手段にて干渉光が検出されなくなり、かつ、いずれの投光手段の投光タイミングとは異なるタイミングにずらす構成としてもよい。 A plurality of light projecting means for irradiating light toward a predetermined detection area; a plurality of light receiving means provided corresponding to each of the plurality of light projecting means and capable of receiving light from the detection area; The plurality of light projecting units are sequentially projected, and a detection object in the detection area is detected based on a light reception signal corresponding to the amount of light received from the corresponding light receiving unit in synchronization with the light projection timing of each light projecting unit. Interfering light is detected based on the light receiving signal from the corresponding light receiving means for each of the light projecting / receiving control means for performing the light projecting / receiving operation and the detection timing at the time of non-light projection before the light projecting timing of each light projecting means. In the multi-optical axis photoelectric sensor provided with the interference light detecting means, the light projecting / receiving control means always causes the plurality of light projecting means to sequentially execute the light projecting / receiving operation at every predetermined light projecting timing, Interferometric light detection When the interference light is detected by the means, only the light projection timing of the light projecting operation of the light projecting means corresponding to the light receiving means in which the interference light is detected, the interference light is not detected by the interference detection means, And it is good also as a structure shifted to the timing different from the light projection timing of any light projection means.

請求項２の発明に係る衝突防止センサは、無人搬送車に配置され当該無人搬送車の走行方向前方の障害物を検出する衝突防止センサであって、
前記走行方向前方の検出領域ヘ向けて光を照射する複数の投光手段と、
前記投光手段から投光され、前記検出領域で反射した光を受光可能な受光手段と、
前記複数の投光手段について順次投光させるとともに、各投光手段の投光タイミングに同期して受光手段からの受光量に応じた受光信号に基づき前記検出領域内の検出物体を検出する投受光動作を行う投受光制御手段と、
前記各投光手段のそれぞれの投光タイミングに対応するタイミングであって、所定の検出タイミング（例えば、投光タイミングの前の所定タイミング）毎に、前記受光手段からの受光信号に基づいて干渉光を検出する干渉光検出手段とを備えた衝突防止センサにおいて、
前記投受光制御手段は、常には、前記複数の投光手段に所定の投光タイミング毎に投受光動作を順次実行させる一方で、
前記干渉光検出手段にて干渉光が検出されたときには、その検出タイミングに対応する投光手段の投光タイミングだけを、いずれの投光手段の投光タイミングとは異なるタイミングにずらす構成としたところに特徴を有する。 The collision prevention sensor according to the invention of claim 2 is a collision prevention sensor that is disposed in an automatic guided vehicle and detects an obstacle ahead of the automatic guided vehicle in the traveling direction,
A plurality of light projecting means for irradiating light toward the detection area forward in the traveling direction;
A light receiving means capable of receiving the light projected from the light projecting means and reflected by the detection region;
Projecting and receiving light that sequentially projects the plurality of light projecting means and detects a detection object in the detection area based on a light reception signal corresponding to the amount of light received from the light receiving means in synchronization with the light projection timing of each light projecting means Light emitting / receiving control means for performing the operation;
Interfering light based on the received light signal from the light receiving means at a timing corresponding to each light projecting timing of each light projecting means and at each predetermined detection timing (for example, a predetermined timing before the light projection timing). In a collision prevention sensor comprising interference light detection means for detecting
While the light projecting / receiving control unit always causes the plurality of light projecting units to sequentially execute a light projecting / receiving operation at every predetermined light projecting timing,
When interference light is detected by the interference light detection means, only the light projection timing of the light projection means corresponding to the detection timing is shifted to a timing different from the light projection timing of any light projection means. It has the characteristics.

なお、無人搬送車に配置され当該無人搬送車の走行方向前方の障害物を検出する衝突防止センサであって、前記走行方向前方の検出領域ヘ向けて光を照射する複数の投光手段と、複数の投光手段のそれぞれに対応して設けられ、前記検出領域からの光を受光可能な複数の受光手段と、前記複数の投光手段について順次投光させるとともに、各投光手段の投光タイミングに同期してそれと対応する受光手段からの受光量に応じた受光信号に基づき前記検出領域内の検出物体を検出する投受光動作を行う投受光制御手段と、前記各投光手段の投光タイミング前の非投光時における検出タイミング毎に、それに対応する受光手段からの受光信号に基づいて干渉光を検出する干渉光検出手段とを備えた衝突防止センサにおいて、前記投受光制御手段は、常には、前記複数の投光手段に所定の投光タイミング毎に投受光動作を順次実行させる一方で、前記干渉光検出手段にて干渉光が検出されたときには、その干渉光が検出された受光手段に対応する投光手段の投光動作の投光タイミングだけを、前記干渉検出手段にて干渉光が検出されなくなり、かつ、いずれの投光手段の投光タイミングとは異なるタイミングにずらす構成としてもよい。 A collision prevention sensor that is disposed in the automatic guided vehicle and detects an obstacle ahead in the traveling direction of the automatic guided vehicle, and a plurality of light projecting units that irradiate light toward the detection area forward in the traveling direction; A plurality of light receiving means provided corresponding to each of the plurality of light projecting means and capable of receiving light from the detection region, and sequentially projecting the plurality of light projecting means, and projecting light from each light projecting means A light projecting / receiving control means for performing a light projecting / receiving operation for detecting a detection object in the detection area based on a light reception signal corresponding to the amount of light received from the corresponding light receiving means in synchronization with the timing, and light projection of each of the light projecting means In the collision prevention sensor comprising the interference light detecting means for detecting the interference light based on the light receiving signal from the light receiving means corresponding to each detection timing at the time of non-light emitting before the timing, the light projecting / receiving control means comprises: While always causing the plurality of light projecting units to sequentially execute the light projecting / receiving operation at every predetermined light projecting timing, when the interference light is detected by the interference light detecting unit, the light reception in which the interference light is detected. Only the light projecting timing of the light projecting operation of the light projecting unit corresponding to the unit is shifted to a timing different from the light projecting timing of any of the light projecting units, with the interference detecting unit detecting no interference light. Also good.

請求項３の発明に係る衝突防止センサは、無人搬送車に配置され当該無人搬送車の走行方向前方の障害物を検出する衝突防止センサであって、
前記走行方向前方の検出領域からの反射光を照射する複数の投光手段と、複数の投光手段のそれぞれに対応して設けられ、前記検出領域からの光を受光可能な複数の受光手段と、前記複数の投光手段について順次投光させるとともに、各投光手段の投光タイミングに同期してそれと対応する受光手段からの受光量に応じた受光信号に基づき前記検出領域内の検出物体を検出する投受光動作を行う投受光制御手段と、検出タイミング毎に、それに対応する受光手段からの受光信号に基づいて干渉光を検出する干渉光検出手段とを備えた衝突防止センサにおいて、
親機とその親機の側方に設けられる子機とを備えて構成され、互いに対応する前記複数の投光手段及び受光手段のうち一部の対応する投光手段及び受光手段は、前記親機において前記検出領域の中央付近に光軸を向けて配置され、残りの対応する投光手段及び受光手段は、前記子機において前記検出領域の周縁部に光軸を向けて配置されており、
前記投受光制御手段は、常には、前記複数の投光手段に所定の投光タイミング毎に投受光動作を順次実行させる一方で、前記干渉光検出手段にて干渉光が検出されたときには、その干渉光が検出された受光手段に対応する投光手段の投光動作の投光タイミングだけを、いずれの投光手段の投光タイミングとは異なるタイミングにずらす構成としたところに特徴を有する。 The collision prevention sensor according to the invention of claim 3 is a collision prevention sensor that is arranged in an automatic guided vehicle and detects an obstacle ahead of the automatic guided vehicle in the traveling direction,
A plurality of light projecting means for irradiating reflected light from the detection area in front of the traveling direction; a plurality of light receiving means provided corresponding to each of the plurality of light projecting means and capable of receiving light from the detection area; The plurality of light projecting units are sequentially projected, and the detection object in the detection region is detected based on a light reception signal corresponding to the amount of light received from the corresponding light receiving unit in synchronization with the light projection timing of each light projecting unit. In a collision prevention sensor comprising a light projection / reception control means for performing a light projection / reception operation to be detected, and an interference light detection means for detecting interference light based on a light reception signal from the corresponding light reception means for each detection timing,
A plurality of light projecting means and light receiving means corresponding to each other, and a part of the corresponding light projecting means and light receiving means, In the machine, the optical axis is arranged near the center of the detection area, and the remaining corresponding light projecting means and light receiving means are arranged in the slave unit with the optical axis directed to the peripheral edge of the detection area,
The light projecting / receiving control means always causes the plurality of light projecting means to sequentially execute the light projecting / receiving operation at every predetermined light projecting timing, while when the interference light detecting means detects the interference light, It is characterized in that only the light projecting timing of the light projecting operation of the light projecting means corresponding to the light receiving means in which the interference light is detected is shifted to a timing different from the light projecting timing of any light projecting means.

＜請求項１の発明及び請求項２の発明＞
本構成によれば、干渉光検出手段にて干渉光が検出されたときには、その干渉光が検出された受光手段に対応する投光手段の投光動作の投光タイミングだけを、いずれの投光手段の投光タイミング及び検出タイミングとは異なるタイミングにずらす構成になっている。換言すれば、干渉光が検出された投光手段及び受光手段の投受光タイミングだけをずらして、干渉光が検出されなかった他の投光手段及び受光手段の投受光動作は、通常の投光タイミングからずらさない構成になっている。これにより、ある受光手段に干渉光が入射した場合であっても、全投光手段及び受光手段による投受光動作が終了するまでの時間が長くなることを抑制することができ、全体として応答速度の遅れを防止することができる。 <Invention of Claim 1 and Invention of Claim 2>
According to this configuration, when the interference light is detected by the interference light detection means, only the light projection timing of the light projection operation of the light projection means corresponding to the light receiving means in which the interference light is detected is set to any light projection. It is configured to shift to a timing different from the light projection timing and detection timing of the means. In other words, by shifting only the light projecting / receiving timings of the light projecting means and the light receiving means in which the interference light is detected, the light projecting / receiving operations of other light projecting means and light receiving means in which the interference light is not detected are the normal light projecting operations. It has a configuration that does not deviate from the timing. Thereby, even when interference light is incident on a certain light receiving means, it is possible to suppress an increase in the time until the light projecting / receiving operation by all the light projecting means and the light receiving means is completed, and the response speed as a whole Can be prevented.

＜請求項３の発明＞
本構成によれば、衝突防止センサは検出領域の中心付近の検出を行う親機と、検出領域の周縁部の検出を行う子機とから構成されているから、親機のみでは検出できない領域を別体として設けられた子機により検出することができる。 <Invention of Claim 3>
According to this configuration, since the collision prevention sensor includes the parent device that detects the vicinity of the center of the detection region and the child device that detects the peripheral portion of the detection region, an area that cannot be detected only by the parent device is detected. It can detect by the subunit | mobile_unit provided as a different body.

＜実施形態１＞
本発明の一実施形態を図１ないし図８を参照して説明する。
１．衝突防止センサの全体構成
本発明の衝突防止センサ１は、図２に示すように、無人搬送車Ｙの前端部中央に前方に向けて配された本体としての親機１０と、この親機１０に対して着脱可能に接続され、無人搬送車Ｙの前端部の両端部にそれぞれ配される子機２０，２０とからなる。そして、無人搬送車Ｙの走行方向前方の所定の検出領域における検出物としての障害物（図示しない）の有無を検出するために用いられるものである。 <Embodiment 1>
An embodiment of the present invention will be described with reference to FIGS.
1. Overall Configuration of Collision Prevention Sensor As shown in FIG. 2, the collision prevention sensor 1 of the present invention includes a master unit 10 as a main body disposed forward in the center of the front end portion of the automatic guided vehicle Y, and the master unit 10. Are connected detachably to the front end of the automatic guided vehicle Y and are arranged at both end portions of the front end portion of the automatic guided vehicle Y, respectively. And it is used in order to detect the presence or absence of an obstacle (not shown) as a detection object in a predetermined detection area in the traveling direction of the automatic guided vehicle Y.

（１）親機
親機１０は、図１に示すように、全体として略直方体状をなし、その内部に対をなす投光素子１１ｂ，１１ｃ（例えば発光ダイオード等）及び受光素子２１ｂ，２１ｃ（例えばフォトダイオード等）が横方向に２組並んで配列されるとともに、その前面部には窓部１０Ａが配設されている。そして、この投光素子１１ｂ，１１ｃから出射されたレーザ光Ｌ２，Ｌ３が窓部１０Ａ，１０Ａを介して検出領域（図２参照）に向け斜め二方向の互いに離れあう光軸を形成すると共に、検出領域から反射されるレーザ光を窓部１０Ａ，１０Ａを介して受光素子２１ｂ，２１ｃにて受光するようになっている。なお、親機１０は、検出領域のうち、主に中心付近の検出が可能となっている。 (1) Base Unit As shown in FIG. 1, the base unit 10 has a substantially rectangular parallelepiped shape as a whole, and a pair of light projecting elements 11b and 11c (for example, light emitting diodes) and light receiving elements 21b and 21c (for example). For example, two sets of photodiodes and the like are arranged side by side in the horizontal direction, and a window portion 10A is disposed on the front surface portion thereof. Then, the laser beams L2 and L3 emitted from the light projecting elements 11b and 11c form optical axes that are separated from each other in two oblique directions toward the detection region (see FIG. 2) through the window portions 10A and 10A. Laser light reflected from the detection region is received by the light receiving elements 21b and 21c through the windows 10A and 10A. The base unit 10 can mainly detect the vicinity of the center in the detection area.

親機１０の背面部には無人搬送車Ｙの走行制御装置１９（図２参照）に接続される接続ケーブル２８が中央部から導出されている。さらに、親機１０の背面部の両端部からはケーブル２９，２９が導出され、これらが二個の子機２０のそれぞれと電気的に接続されるようになっている。 A connection cable 28 connected to the traveling control device 19 (see FIG. 2) of the automatic guided vehicle Y is led out from the central portion of the back surface of the master unit 10. Further, cables 29 and 29 are led out from both ends of the back surface of the base unit 10 and are electrically connected to each of the two slave units 20.

（２）子機
子機２０，２０は、同一構成であり、全体として略直方体状をなし、前面部に投受光のための窓部２０Ａが配設され、その内部に対をなす投光素子１１ａ（１１ｄ）及び受光素子２１ａ（２１ｄ）が一組ずつ配列されている。そして、投光素子１１ａ（１１ｄ）から出射されたレーザ光Ｌ１（Ｌ４）が窓部２０Ａを介して検出領域に向けて一方向（前方）の光軸を形成すると共に、検出領域から反射されるレーザ光を受光素子２１ａ（２１ｄ）にて受光するようになっている。なお、子機２０，２０のレーザ光Ｌ１（Ｌ４）は検出領域のうち親機１０では十分に検出できない両側部を検出できるようになっている。
このように、衝突防止センサ１は検出領域の中心付近の検出を行う親機１０と、検出領域の周縁部の検出を行う子機２０とから構成されているから、親機１０のみでは検出できない領域を別体として設けられた子機２０により検出することができるようになっている。 (2) Slave unit The slave units 20 and 20 have the same configuration, have a substantially rectangular parallelepiped shape as a whole, and have a light projecting element which is provided with a window portion 20A for projecting and receiving light on the front surface portion, and forms a pair therein. 11a (11d) and light receiving elements 21a (21d) are arranged one by one. Then, the laser beam L1 (L4) emitted from the light projecting element 11a (11d) forms an optical axis in one direction (forward) toward the detection region via the window portion 20A and is reflected from the detection region. Laser light is received by the light receiving element 21a (21d). The laser beams L1 (L4) of the slave units 20 and 20 can detect both sides of the detection region that cannot be sufficiently detected by the master unit 10.
As described above, the collision prevention sensor 1 includes the parent device 10 that detects the vicinity of the center of the detection region and the child device 20 that detects the peripheral portion of the detection region. The area can be detected by the handset 20 provided as a separate body.

２．電気的構成
実施形態の電気的構成を図３に示す。なお、本実施形態では、親機１０のみに制御部１５が備えられ、この制御部１５が親機１０内の回路及びケーブル２９，２９を介して２個の子機２０，２０内の各回路を制御するようになっている。 2. Electrical Configuration The electrical configuration of the embodiment is shown in FIG. In the present embodiment, the control unit 15 is provided only in the base unit 10, and the control unit 15 includes circuits in the base unit 10 and the circuits in the two slave units 20 and 20 via the cables 29 and 29. Is to control.

衝突防止センサ１には、各投光素子１１ａ〜１１ｄそれぞれに対応して４つの駆動回路１２ａ〜１２ｄが設けられ、制御部１５から送信される投受光信号Ｐ１〜Ｐ４を受けることでそれぞれに対応した各投光素子１１ａ〜１１ｄに駆動電流を供給して投光動作をさせるようになっている。
また、各受光素子２１ａ〜２１ｄそれぞれに対応して４つの受光アンプ２２ａ〜２２ｄが設けられ、それに対応する受光素子２１ａ〜２１ｄからの受光量に応じた受光信号Ｄ１〜Ｄ４を所定の増幅率で増幅して出力するようになっている。また、各受光アンプ２２ａ〜２２ｄの出力側にそれぞれアナログスイッチ１４ａ〜１４ｄを介してコンパレータ１３ａ〜１３ｄの入力が接続されている。
各アナログスイッチ１４ａ〜１４ｄの制御端子には、制御部１５から送信される上記投受光信号Ｐ１〜Ｐ４が与えられ、これにより各受光アンプ２２ａ〜２２ｄからの受光信号が有効化されてコンパレータ１３ａ〜１３ｄに与えられるようになっている。また、各アナログスイッチ１４ａ〜１４ｄの制御端子には、制御部１５から干渉光検出タイミングで送信される干渉検出信号Ｅ１〜Ｅ４も与えられ、これにより各受光アンプ２２ａ〜２２ｄからの受光信号が有効化されてコンパレータ１３ａ〜１３ｄに与えられるようになっている。 The collision prevention sensor 1 is provided with four drive circuits 12a to 12d corresponding to each of the light projecting elements 11a to 11d, and responds to each by receiving the light projection / reception signals P1 to P4 transmitted from the control unit 15. A drive current is supplied to each of the light projecting elements 11a to 11d to perform a light projecting operation.
In addition, four light receiving amplifiers 22a to 22d are provided corresponding to the respective light receiving elements 21a to 21d, and light receiving signals D1 to D4 corresponding to the amounts of light received from the light receiving elements 21a to 21d corresponding to the light receiving amplifiers 22a to 22d are provided at a predetermined amplification factor. Amplified and output. The inputs of the comparators 13a to 13d are connected to the output sides of the light receiving amplifiers 22a to 22d via the analog switches 14a to 14d, respectively.
The light projection / reception signals P1 to P4 transmitted from the control unit 15 are given to the control terminals of the analog switches 14a to 14d, whereby the light reception signals from the respective light reception amplifiers 22a to 22d are validated, and the comparators 13a to 13d. 13d. The control terminals of the analog switches 14a to 14d are also provided with interference detection signals E1 to E4 transmitted from the control unit 15 at the interference light detection timing, whereby the light reception signals from the light reception amplifiers 22a to 22d are effective. And supplied to the comparators 13a to 13d.

各コンパレータ１３ａ〜１３ｄは、各受光アンプ２２ａ〜２２ｄからの受光信号レベルと所定の閾値レベルとを比較し、その大小比較に応じて検出信号を出力し、これが制御部１５に与えられる。なお、コンパレータ１３ａ〜１３ｄを、検出物の検出用の閾値を有する物体検出用のコンパレータと、干渉光検出用の閾値を有する干渉検出用のコンパレータとをそれぞれ備えた構成であってもよい。また、各受光アンプ２２ａ〜２２ｄからの受光信号を共通のコンパレータ（物体検出用のコンパレータ、干渉光検出用のコンパレータ）に与えて順次比較動作を行う構成であってもよい。そして、制御部１５では、この検出信号に基づいて検出領域における障害物の検出や、干渉光の入射の有無を検出を行い、その結果を例えばディスプレイ等の表示部３１にて表示させるようになっている。 Each of the comparators 13 a to 13 d compares the light reception signal level from each of the light reception amplifiers 22 a to 22 d with a predetermined threshold level, and outputs a detection signal according to the magnitude comparison, which is given to the control unit 15. The comparators 13a to 13d may be configured to include an object detection comparator having a detection object detection threshold and an interference detection comparator having an interference light detection threshold. Alternatively, the light receiving signals from the light receiving amplifiers 22a to 22d may be supplied to a common comparator (object detection comparator, interference light detection comparator) to sequentially perform comparison operations. Based on this detection signal, the control unit 15 detects an obstacle in the detection region and detects the presence or absence of interference light, and displays the result on the display unit 31 such as a display. ing.

３．制御部による制御
次に、本実施形態に係る衝突防止センサ１の制御部１５における処理について図４から図７に示すフローチャートを参照しつつ説明する。
衝突防止センサ１の電源をオン操作すると、図４に示すように、制御部１５は所定の時間間隔（ｔ１）で時分割された投受光タイミング信号を生成（Ｓ１１）し、この投受光タイミング信号に従って、投受光信号Ｐ１を駆動回路１２ａ及びアナログスイッチ１４ａに与える（Ｓ１２）。すると、投光素子１１ａが投光動作を行うとともに、それに同期して受光素子２１ａからの受光信号がコンパレータ１３ａに与えられ、ここから検出信号が制御部１５に与えられる。以下、この動作を投受光動作をいう。 3. Control by Control Unit Next, processing in the control unit 15 of the collision prevention sensor 1 according to the present embodiment will be described with reference to the flowcharts shown in FIGS.
When the power supply of the collision prevention sensor 1 is turned on, as shown in FIG. 4, the control unit 15 generates a light transmission / reception timing signal time-divided at a predetermined time interval (t1) (S11). Accordingly, the light projection / reception signal P1 is given to the drive circuit 12a and the analog switch 14a (S12). Then, the light projecting element 11a performs a light projecting operation, and a light reception signal from the light receiving element 21a is given to the comparator 13a in synchronization therewith, and a detection signal is given to the control unit 15 therefrom. Hereinafter, this operation is referred to as a light projecting / receiving operation.

次に、この投受光動作が終わるとすぐに、制御部１５は干渉検出信号Ｅ２をアナログスイッチ１４ｂに与えて（Ｓ１３）、受光アンプ２２ｂからの受光信号がコンパレータ１３ｂに入力され、ここから検出信号が制御部１５に出力される。そして、投受光信号Ｐ１のタイミングからｔ１−ｔ３経過（所定時間間隔ｔ１よりも微小時間ｔ３早い時間）まで行い（Ｓ１４で「Ｙ」）、ｔ１−ｔ３経過した時点で、制御部１５では、コンパレータ１３ｂから出力された信号が例えばハイレベルであれば、受光素子２１ｂに干渉光ありと検出し、コンパレータ１３ｂから出力された信号がローレベルであれば、受光素子２１ｂに干渉光なしと判断する（Ｓ１５）。
この制御部１５で、干渉光検出とされなかった場合には、このまま通常の動作（干渉なしルーチン）を継続する（Ｓ１５で「Ｙ］）。一方、干渉光検出とされた場合には、後述する干渉有りルーチンＡを実施する（Ｓ１５で「Ｎ］）。 Next, as soon as the light projecting / receiving operation is finished, the control unit 15 gives the interference detection signal E2 to the analog switch 14b (S13), and the light receiving signal from the light receiving amplifier 22b is inputted to the comparator 13b, from which the detection signal is detected. Is output to the control unit 15. Then, from the timing of the light projecting / receiving signal P1, t1 to t3 elapse (a time that is a minute time t3 earlier than the predetermined time interval t1) is performed ("Y" in S14), and when t1 to t3 elapses, the control unit 15 For example, if the signal output from 13b is at a high level, it is detected that there is interference light in the light receiving element 21b. If the signal output from the comparator 13b is at a low level, it is determined that there is no interference light in the light receiving element 21b ( S15).
If the control unit 15 does not detect the interference light, the normal operation (interference-free routine) is continued as it is (“Y” in S15). The interference routine A is performed (“N” in S15).

（１）干渉なしの場合
干渉なしルーチンでは、制御部１５はＰ２の投受光タイミングの直前（ｔ３時間前）でアナログスイッチ１４ｂをオフした後、制御部１５はＰ２の投受光タイミング（ｔ２´）で（Ｓ１６で「Ｙ］）、投受光信号Ｐ２を出力する（Ｓ１７）。すると、投受光信号Ｐ２は、駆動回路１２ｂを起動させるとともに、投受光信号Ｐ２によりアナログスイッチ１４ｂがオンされて、受光アンプ２２ｂから出力される受光信号が有効化される。
次に、この投受光動作が終わるとすぐに、制御部１５はアナログスイッチ１４ｂの制御端子に、制御部１５から干渉光検出タイミングで送信される干渉検出信号Ｅ２を与え（Ｓ１８）、受光アンプ２２ｂから出力される受光信号を有効化する。これにより受光アンプ２２ｃから出力された受光信号はコンパレータ１３ｃに入力され、その受光信号を受光レベルに応じた検出信号としてコンパレータ１３ｂから制御部１５に出力される。そして、ｔ１−ｔ３経過した時点で（Ｓ１９で「Ｙ］）、制御部１５では、コンパレータ１３ｃから出力された信号がハイレベルであれば、受光素子２１ｂに干渉光ありと検出し（Ｓ２０で「Ｙ］）、コンパレータ１３ｂから出力された信号がローレベルであれば、受光素子２１ｂに干渉光なしと検出する（Ｓ２０で「Ｎ］）。 (1) When there is no interference In the no interference routine, the control unit 15 turns off the analog switch 14b immediately before the light projecting / receiving timing of P2 (before time t3), and then the control unit 15 performs the light projecting / receiving timing (t2 ') of P2. ("Y" in S16), the light projection / reception signal P2 is output (S17), and the light projection / reception signal P2 activates the drive circuit 12b and the analog switch 14b is turned on by the light projection / reception signal P2 to receive light. The light reception signal output from the amplifier 22b is validated.
Next, as soon as this light projecting / receiving operation is finished, the control unit 15 gives the interference detection signal E2 transmitted from the control unit 15 at the interference light detection timing to the control terminal of the analog switch 14b (S18), and the light receiving amplifier 22b. Validate the light reception signal output from. As a result, the light reception signal output from the light reception amplifier 22c is input to the comparator 13c, and the light reception signal is output from the comparator 13b to the control unit 15 as a detection signal corresponding to the light reception level. When t1-t3 has elapsed (“Y” in S19), the control unit 15 detects that the light receiving element 21b has interference light if the signal output from the comparator 13c is at a high level (“ Y]), if the signal output from the comparator 13b is at a low level, it is detected that there is no interference light in the light receiving element 21b (“N” in S20).

この制御部１５で、干渉光ありと検出された場合には、後述する干渉有りルーチンＢを実施する。
その後は、投受光信号Ｐ３についても、上記と同様に投受光信号Ｐ２のタイミング（ｔ３´）で投受光動作等を行い（Ｓ２１からＳ２４）、干渉光検出とされた場合には、後述する干渉有りルーチンＣを実施する（Ｓ２５で「Ｙ］）。そして、制御部１５がＰ４の投受光タイミング（ｔ４´）で（Ｓ２６で「Ｙ］）、投受光信号Ｐ４を出力する（Ｓ２７）ことにより、投光素子１１ｄ及び対応する受光素子２１ｄの投受光動作が行われ、干渉光が受光素子２１ｂ〜２１ｄのいずれにも入射しなかった場合の障害物検出センサの１スキャン動作（レーザ光Ｌ１〜Ｌ４の投光動作）が終了する。 When the control unit 15 detects that there is interference light, an interference presence routine B described later is executed.
Thereafter, the light projection / reception signal P3 is also subjected to the light projection / reception operation at the timing (t3 ') of the light projection / reception signal P2 in the same manner as described above (S21 to S24). Existence routine C is executed (“Y” in S25), and the control unit 15 outputs the light transmission / reception signal P4 (S27) at the light transmission / reception timing (t4 ′) of P4 (“Y” in S26). When the light projecting / receiving operation of the light projecting element 11d and the corresponding light receiving element 21d is performed, and the interference light is not incident on any of the light receiving elements 21b to 21d, one scan operation of the obstacle detection sensor (laser light L1 to L1) The L4 light projection operation) ends.

（２）干渉光ありの場合
（ａ）干渉ありルーチンＡ
干渉ありルーチンＡでは、図５に示すように、制御部１５はＰ２の投受光タイミングの直前（ｔ３時間前）を経過した後も、ｔ３時間毎にアナログスイッチ１４ｂの制御端子に、干渉光検出タイミングで送信される干渉検出信号Ｅ２を与え、投受光信号Ｐ１のタイミング（ｔ１´）から２ｔ１−２ｔ３経過（所定時間間隔ｔ１の二倍の時間よりも微小時間ｔ３の二倍早い時間）まで、受光アンプ２２ｂから出力される受光信号の有効化を継続する（Ｓ３１で「Ｎ」，Ｓ３２）。制御部１５ではその都度干渉光の有無を検出し、干渉光が検出されなくなったら、その時点で投受光信号Ｐ２を出力する（Ｓ３３で「Ｎ」，Ｓ３５）。干渉光が検出された場合には、投受光信号Ｐ１のタイミング（ｔ１´）から２ｔ１−２ｔ３経過するまで、ｔ３時間経過毎に行われる（Ｓ３４）。 (2) When there is interference light (a) Routine A with interference
In the routine A with interference, as shown in FIG. 5, the control unit 15 detects the interference light at the control terminal of the analog switch 14b every t3 hours even after the time immediately before the light projecting / receiving timing of P2 (t3 hours before). The interference detection signal E2 transmitted at the timing is given, and from the timing (t1 ′) of the light projection / reception signal P1 until 2t1-2t3 has elapsed (a time that is twice as short as the minute time t3 than the time that is twice the predetermined time interval t1), The validation of the light reception signal output from the light reception amplifier 22b is continued ("N" in S31, S32). The controller 15 detects the presence / absence of interference light each time, and when the interference light is no longer detected, outputs the light projection / reception signal P2 at that time ("N" in S33, S35). When the interference light is detected, it is performed every time t3 until 2t1-2t3 elapses from the timing (t1 ′) of the light projecting / receiving signal P1 (S34).

一方、投受光信号Ｐ１のタイミング（ｔ１´）から２ｔ１−２ｔ３経過した場合には（Ｓ３１で「Ｙ」）、干渉光の検出が中断され、制御部１５はＰ３の投受光タイミング（ｔ３´）で（Ｓ３６で「Ｙ］）、投受光信号Ｐ３を出力する（Ｓ３７）。 On the other hand, when 2t1-2t3 has elapsed from the timing (t1 ′) of the light projection / reception signal P1 (“Y” in S31), the detection of the interference light is interrupted, and the control unit 15 performs the light projection / reception timing (t3 ′) of P3. ("Y" in S36), the light projection / reception signal P3 is output (S37).

その後、投受光信号Ｐ１のタイミング（ｔ１´）から３ｔ１−２ｔ３経過するまで、再び受光アンプ２２ｂから出力される受光信号の有効化を継続する（Ｓ３８で「Ｎ」，Ｓ３９）。制御部１５ではその都度干渉光の有無を検出し、干渉光が検出されなくなったら、その時点で投受光信号Ｐ２を出力する（Ｓ４０で「Ｎ」，Ｓ４２）。干渉光が検出された場合には、投受光信号Ｐ１のタイミング（ｔ１´）から２ｔ１−２ｔ３経過するまで、ｔ３時間経過毎に行われる（Ｓ４１）。 Thereafter, the activation of the light reception signal output from the light reception amplifier 22b is continued again until 3t1-2t3 elapses from the timing (t1 ′) of the light projection / reception signal P1 (“N” in S38, S39). The controller 15 detects the presence / absence of interference light each time, and when the interference light is not detected, outputs the light projection / reception signal P2 at that time ("N" in S40, S42). When the interference light is detected, the process is performed every time t3 until 2t1-2t3 elapses from the timing (t1 ′) of the light projection / reception signal P1 (S41).

一方、投受光信号Ｐ１のタイミング（ｔ１´）から３ｔ１−２ｔ３経過した場合には（Ｓ３８で「Ｙ」）、干渉光の検出が中断され、制御部１５はＰ３の投受光タイミング（ｔ４´）で（Ｓ４３で「Ｙ］）、投受光信号Ｐ４を出力する（Ｓ４４）。 On the other hand, when 3t1-2t3 has elapsed from the timing (t1 ′) of the light projection / reception signal P1 (“Y” in S38), the detection of the interference light is interrupted, and the control unit 15 performs the light projection / reception timing (t4 ′) of P3. ("Y" in S43), the light projection / reception signal P4 is output (S44).

その後すぐに、制御部１５は、受光素子２１ｂに干渉光が入射した旨の警報を表示部３１に送信し（Ｓ４５）、（障害物検出センサの１スキャン動作（レーザ光Ｌ１〜Ｌ４のうちＬ２を除く投光動作）が終了する。これにより、作業者は、受光素子２１ｂに干渉光が入射することにより、レーザ光Ｌ２については、障害物の検出が行われなかったことを知ることができる。 Immediately thereafter, the control unit 15 transmits an alarm to the effect that interference light has entered the light receiving element 21b to the display unit 31 (S45), (one scan operation of the obstacle detection sensor (L2 of the laser beams L1 to L4). Thus, the operator can know that no obstacle has been detected for the laser light L2 when the interference light is incident on the light receiving element 21b. .

（ｂ）干渉ありルーチンＢ
干渉ありルーチンＢでは、図６に示すように、制御部１５はＰ３の投受光タイミングの直前（ｔ３時間前）を経過した後も、ｔ３時間毎にアナログスイッチ１４ｃの制御端子に、干渉光検出タイミングで送信される干渉検出信号Ｅ３を与え、投受光信号Ｐ２のタイミング（ｔ２´）から２ｔ１−２ｔ３経過（所定時間間隔ｔ１の二倍の時間よりも微小時間ｔ３の二倍早い時間）まで、受光アンプ２２ｂから出力される受光信号の有効化を継続する（Ｓ５１で「Ｎ」，Ｓ５２）。制御部１５ではその都度干渉光の有無を検出し、干渉光が検出されなくなったら、その時点で投受光信号Ｐ３を出力する（Ｓ５３で「Ｎ」，Ｓ５５）。干渉光が検出された場合には、投受光信号Ｐ１のタイミング（ｔ１´）から２ｔ１−２ｔ３経過するまで、ｔ３時間経過毎に行われる（Ｓ５４）。 (B) Routine B with interference
In the routine B with interference, as shown in FIG. 6, the control unit 15 detects the interference light at the control terminal of the analog switch 14c every t3 hours even after the time immediately before the light projecting / receiving timing of P3 (t3 hours before). The interference detection signal E3 transmitted at the timing is given, and from the timing (t2 ′) of the light projecting / receiving signal P2, 2t1-2t3 has elapsed (a time that is twice as short as the minute time t3 than the time that is twice the predetermined time interval t1). The validation of the light reception signal output from the light reception amplifier 22b is continued ("N" in S51, S52). The controller 15 detects the presence / absence of interference light each time, and when the interference light is not detected, outputs the light projection / reception signal P3 at that time (“N” in S53, S55). When the interference light is detected, it is performed every time t3 until 2t1-2t3 elapses from the timing (t1 ′) of the light projection / reception signal P1 (S54).

一方、投受光信号Ｐ２のタイミング（ｔ２´）から２ｔ１−２ｔ３経過した場合には（Ｓ５１で「Ｙ」）、干渉光の検出が中断され、制御部１５はＰ４の投受光タイミング（ｔ４´）で（Ｓ５６で「Ｙ］）、投受光信号Ｐ４を出力する（Ｓ５７）。 On the other hand, when 2t1-2t3 has elapsed from the timing (t2 ′) of the light projection / reception signal P2 (“Y” in S51), the detection of the interference light is interrupted, and the control unit 15 performs the light projection / reception timing (t4 ′) of P4. ("Y" in S56), the light projection / reception signal P4 is output (S57).

その後すぐに、制御部１５は、受光素子２１ｃに干渉光が入射した旨の警報を表示部３１に送信し（Ｓ５８）、障害物検出センサの１スキャン動作（レーザ光Ｌ１〜Ｌ４のうちＬ３を除く投光動作）が終了する。 Immediately thereafter, the control unit 15 transmits an alarm indicating that the interference light has entered the light receiving element 21c to the display unit 31 (S58), and performs one scan operation of the obstacle detection sensor (L3 of the laser beams L1 to L4). Excluding the light projection operation) ends.

（ｃ）干渉ありルーチンＣ
干渉ありルーチンＣでは、図７に示すように、制御部１５は、制御部１５はＰ４の投受光タイミング（ｔ４´）で（Ｓ６０で「Ｙ］）、投受光信号Ｐ４を出力する（Ｓ６１）。 (C) Routine C with interference
In the routine C with interference, as shown in FIG. 7, the control unit 15 outputs the light projection / reception signal P4 at the light transmission / reception timing (t4 ′) of P4 (“Y” in S60) (S61). .

その後すぐに、制御部１５は、受光素子２１ｄに干渉光が入射した旨の警報を表示部３１に送信し（Ｓ６２）、障害物検出センサの１スキャン動作（レーザ光Ｌ１〜Ｌ４のうちＬ４を除く投光動作）が終了する。 Immediately thereafter, the control unit 15 transmits an alarm indicating that the interference light has entered the light receiving element 21d to the display unit 31 (S62), and performs one scan operation of the obstacle detection sensor (L4 among the laser beams L1 to L4). Excluding the light projection operation) ends.

なお、一つの受光素子２１のみが干渉光を受光する場合について説明したが、各受光素子２１について、それぞれの受光タイミングで複数の受光素子２１に干渉光が入射した場合には、干渉光が入射した複数の受光素子２１と対応する投光素子の投受光動作を遅らせて（ずらして）もよい。 The case where only one light receiving element 21 receives the interference light has been described. However, for each light receiving element 21, when the interference light is incident on the plurality of light receiving elements 21 at the respective light receiving timings, the interference light is incident. The light projecting / receiving operation of the light projecting elements corresponding to the plurality of light receiving elements 21 may be delayed (shifted).

ここで、例えば、外部からの照明等や、別体として設けられた他の衝突防止センサ等からの干渉光が受光素子に入射することがあり、このような干渉光が投光タイミングと重なるタイミングで受光素子２１ｂに入射した場合には（図８（ａ）参照）、その受光素子２１ｂについては干渉光の影響により受光量レベルが変化してしまい障害物の存在を正確に検出することができない。このとき、図８（ｂ）に示すように、干渉光の影響を受けない入射タイミングとなるまで、当該受光素子２１ｂと対応する投光素子１１ｂ及びそれ以後の投光素子１１ｃ，１１ｄの投光タイミングを同期させつつ所定時間遅らせた場合には、、後の投受光動作がその遅れ時間だけ遅れ、その結果、物体の検出時間が遅くなってしまう。 Here, for example, interference light from outside illumination or other collision prevention sensors provided separately may enter the light receiving element, and such interference light overlaps with the light projection timing. When the light is incident on the light receiving element 21b (see FIG. 8A), the light receiving level of the light receiving element 21b changes due to the influence of interference light, and the presence of an obstacle cannot be accurately detected. . At this time, as shown in FIG. 8B, the light projecting elements 11b corresponding to the light receiving element 21b and the light projecting elements 11c and 11d thereafter are projected until the incident timing is not affected by the interference light. When the timing is delayed for a predetermined time, the subsequent light projecting / receiving operation is delayed by the delay time, and as a result, the object detection time is delayed.

そこで、本実施形態のように、制御部１５により干渉光が検出されたときには、この干渉光を受光した受光素子２１ｂ（２１ｃ）と対応する投光素子１１ｂ（１１ｃ）については、干渉光が受光素子２１ｂ（２１ｃ）に入射しないタイミングに、当該投光素子１１ｂ（１１ｃ）の投光タイミングをずらして投光させるとともに、投光素子１１ｂ（１１ｃ）以外の投光素子１１ａ，１１ｄ（１１ｂ，１１ｃ）は、通常時と同じ投光タイミングで投光させることにより、図８（ｃ）に示すように、全投光素子１１ａ〜１１ｄ及び受光素子２１ａ〜２１ｄによる投受光動作が終了するまでの時間が長くなることを抑制することができ、全体として検出時間（応答速度）を遅らせることなく障害物の検出を行うことが可能になる。また、図８（ｄ）に示すように、受光素子２１ｂ（２１ｃ）が投光素子１１ｃ，１１ｄからの光の干渉を受けないタイミングにずらして当該受光素子２１ｂ（２１ｃ）と対応する投光素子１１ｂ（１１ｃ）を投光させるから、正確に被検出物の検出を行うことができる。 Therefore, as in the present embodiment, when the interference light is detected by the control unit 15, the interference light is received by the light projecting element 11b (11c) corresponding to the light receiving element 21b (21c) that has received the interference light. The light projection timing of the light projecting element 11b (11c) is shifted at a timing when it does not enter the element 21b (21c), and the light projecting elements 11a, 11d (11b, 11c) other than the light projecting element 11b (11c) are used. ) Is a time until the light projecting / receiving operation by all the light projecting elements 11a to 11d and the light receiving elements 21a to 21d is completed as shown in FIG. Can be suppressed, and the obstacle can be detected without delaying the detection time (response speed) as a whole. Further, as shown in FIG. 8D, the light projecting element corresponding to the light receiving element 21b (21c) is shifted to a timing at which the light receiving element 21b (21c) does not receive light interference from the light projecting elements 11c and 11d. Since 11b (11c) is projected, the detection object can be accurately detected.

＜実施形態２＞
次に、本発明の多光軸光電センサの一実施形態を図９及び図１０によって説明する。
本実施形態の多光軸光電センサ５５は、複数の投光素子１１ａ〜１１ｄが上下に一列に並んで配された投光器５０と、前記投光素子１１ａ〜１１ｄと対を成す複数の受光素子２１ａ〜２１ｄが上下に一列に並んで配された受光器６０とをケーブル５１で接続しつつ対向配置した構成であり、これら投光器５０と受光器６０の間の検出領域における検出物体の有無を検出可能ないわゆる透過型の多光軸光電センサ５５である。
なお、以下では、前記第１実施形態と異なる点のみを説明し第１実施形態と重複する部分については同一符号を付して説明を省略する。 <Embodiment 2>
Next, an embodiment of the multi-optical axis photoelectric sensor of the present invention will be described with reference to FIGS.
The multi-optical axis photoelectric sensor 55 of the present embodiment includes a light projector 50 in which a plurality of light projecting elements 11a to 11d are arranged in a line in the vertical direction, and a plurality of light receiving elements 21a that make a pair with the light projecting elements 11a to 11d. ˜21d are arranged so as to face each other while being connected with a light receiver 60 arranged in a line in the vertical direction, and the presence or absence of a detection object in a detection region between the light projector 50 and the light receiver 60 can be detected. This is a so-called transmission type multi-optical axis photoelectric sensor 55.
In the following description, only the differences from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

本実施形態の多光軸光電センサ５５は、投光器５０と受光器６０に分けられているため、投光器５０側に駆動回路１２（１２ａ〜１２ｄ）等の投光動作に関する回路が組込まれ、受光器６０側に受光アンプ２２ａ〜２２ｄ等の受光動作に関する回路が組み込まれている。また、制御部１５は、受光器６０のみに設けられ、ケーブル５１により、制御部１５からの信号が投光器５０側に送信できるようになっている。これにより制御部１５は、投受光信号Ｐ１〜Ｐ４を駆動回路１２に送信し、投光素子１１ａ〜１１ｄを所望の投光タイミングで投光できるようになっている。 Since the multi-optical axis photoelectric sensor 55 of the present embodiment is divided into a projector 50 and a light receiver 60, a circuit relating to a light projecting operation such as a drive circuit 12 (12a to 12d) is incorporated on the light projector 50 side. Circuits related to light receiving operations such as the light receiving amplifiers 22a to 22d are incorporated on the 60 side. The control unit 15 is provided only in the light receiver 60, and a signal from the control unit 15 can be transmitted to the projector 50 side by the cable 51. Thereby, the control part 15 can transmit the light projection / reception signals P1-P4 to the drive circuit 12, and can project the light projecting elements 11a-11d at a desired light projecting timing.

＜他の実施形態＞
本発明は上記記述及び図面によって説明した実施形態に限定されるものではなく、例えば次のような実施形態も本発明の技術的範囲に含まれ、さらに、下記以外にも要旨を逸脱しない範囲内で種々変更して実施することができる。
（１）本実施形態の衝突防止センサ１では、親機１０と子機２０，２０とに分けて構成されたが、分けて構成されていなくてもよく、例えば、親機と子機を一体とした衝突防止センサであってもよい。 <Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the collision prevention sensor 1 of the present embodiment, the main unit 10 and the sub units 20 and 20 are configured separately. However, the main unit and the sub unit may be integrated, for example. The anti-collision sensor may be used.

（２）干渉光の受光信号の有効化のタイミングは対応する投受光素子１１，２１の投受光動作の前であれば、その有効化の時間や回数は上記実施形態に記載のものに限定されない。 (2) If the timing of activation of the received light signal of the interference light is before the light projecting / receiving operation of the corresponding light projecting / receiving element 11, 21, the time and frequency of the activation are not limited to those described in the above embodiment. .

（３）上記実施形態では、四本の光軸を形成する構成としたが、これ以外の数の光軸を形成してもよい。また、上記実施形態では、４つ投光素子１１ａ〜１１ｄと４つ受光素子２１ａ〜２１ｄを備え、投光素子と受光素子の数を同じにしたが、これに限らず、投光素子と受光素子の数が異なるものであってもよい。例えば、１つの受光素子に複数の投光素子からのレーザ光が順番に入射する構成であってもよい。 (3) In the above embodiment, four optical axes are formed. However, other numbers of optical axes may be formed. In the above-described embodiment, the four light projecting elements 11a to 11d and the four light receiving elements 21a to 21d are provided, and the number of the light projecting elements and the light receiving elements is the same. The number of elements may be different. For example, the structure which the laser beam from a some light projection element injects into one light receiving element in order may be sufficient.

（４）本実施形態の多光軸光電センサ５５では、制御部１５を受光器のみに設けたが、投光器のみに設けてもよい。また、投光器及び受光器にそれぞれ制御部１５を設け、投受光動作を同期させる際には、例えば、受光器から投光器に同期信号を送信して、投受光動作を同期させてもよい。 (4) In the multi-optical axis photoelectric sensor 55 of the present embodiment, the control unit 15 is provided only in the light receiver, but may be provided only in the light projector. In addition, when the control unit 15 is provided in each of the projector and the light receiver and the light projecting / receiving operation is synchronized, for example, a synchronization signal may be transmitted from the light receiver to the light projector to synchronize the light projecting / receiving operation.

（５）上記実施形態では、投受光信号Ｐ１の前には受光素子２１ａについての干渉光の検出をしなかったが、受光素子２１ａについても干渉光を検出してもよく、受光素子２１ａについて干渉光が検出された場合には、投光素子１１ａ及び受光素子２１ａについての投受光信号Ｐ１のタイミングをずらすようにしてもよい。 (5) In the above embodiment, the interference light for the light receiving element 21a is not detected before the light projection / reception signal P1, but the interference light may also be detected for the light receiving element 21a, and the light interference for the light receiving element 21a. When light is detected, the timing of the light projecting / receiving signal P1 for the light projecting element 11a and the light receiving element 21a may be shifted.

（６）実施形態２では、透過型の多光軸光電センサ５５としたが、反射したレーザ光の受光量に基づいて物体を検出するいわゆる反射型の多光軸光電センサであってもよい。 (6) Although the transmissive multi-optical axis photoelectric sensor 55 is used in the second embodiment, a so-called reflective multi-optical axis photoelectric sensor that detects an object based on the amount of received laser light may be used.

（７）上記実施形態では、制御部１５にて干渉光検出と判断した場合には、干渉光が検出されなくなるまで干渉光の検出を継続し、干渉光が検出されなくなった時点から微小時間ｔ３後に投光素子１１ｂ（１１ｃ）及び受光素子２１ｂ（１１ｃ）についての投受光信号Ｐ２（Ｐ３）を送信することとしたが、制御部１５にて干渉光検出と判断した場合には、所定のタイミングに投受光信号Ｐ２（Ｐ３）のタイミングをずらすようにしてもよい。 (7) In the above embodiment, when the control unit 15 determines that the interference light is detected, the detection of the interference light is continued until the interference light is no longer detected. Although the light transmission / reception signal P2 (P3) for the light projecting element 11b (11c) and the light receiving element 21b (11c) is transmitted later, if the control unit 15 determines that the interference light is detected, a predetermined timing is used. Alternatively, the timing of the light projection / reception signal P2 (P3) may be shifted.

本発明の第１実施形態に係る衝突防止センサの斜視図The perspective view of the collision prevention sensor which concerns on 1st Embodiment of this invention. 衝突防止センサが無人搬送車に搭載された状態を示す概念図Conceptual diagram showing a state where the collision prevention sensor is mounted on the automatic guided vehicle 衝突防止センサの電気的構成を示す図Diagram showing the electrical configuration of the collision prevention sensor 衝突防止センサの制御部の処理を示すフローチャートFlow chart showing processing of control unit of collision prevention sensor 干渉有りルーチンＡのフローチャートFlow chart of routine A with interference 干渉有りルーチンＢのフローチャートFlow chart of routine B with interference 干渉有りルーチンＣのフローチャートFlow chart of routine C with interference （ａ）通常動作時の外乱光の入射タイミングを示すタイムチャート（ｂ）後の全ての投光動作を遅らせたときのタイムチャート（ｃ）投受光信号Ｐ２のみ遅らせたときのタイムチャート（ｄ）投受光信号Ｐ２をＰ３の後まで遅らせたときのタイムチャート(A) Time chart showing incident timing of disturbance light during normal operation (b) Time chart when delaying all subsequent light projection operations (c) Time chart when delaying only the light projection / reception signal P2 (d) Time chart when projecting / receiving signal P2 is delayed until after P3 本発明の第２実施形態に係る多光軸光電センサの斜視図The perspective view of the multi-optical axis photoelectric sensor which concerns on 2nd Embodiment of this invention. 多光軸光電センサの電気的構成を示す図The figure which shows the electrical constitution of a multi-optical axis photoelectric sensor （ａ）従来の通常動作時の外乱光の入射タイミングを示すタイムチャート（ｂ）従来の後の全ての投光動作を遅らせたときのタイムチャート(A) Time chart showing the incident timing of disturbance light during conventional normal operation (b) Time chart when delaying all subsequent light projection operations

Explanation of symbols

１０…親機
１１ａ〜１１ｄ…投光素子
１２ａ〜１２ｄ…駆動回路
１３ａ〜１３ｄ…コンパレータ
１４ａ〜１４ｄ…アナログスイッチ
１５…制御部
２０…子機
２１ｂ〜２１ｄ…受光素子
２２ａ〜２２ｄ…受光アンプ
５０…投光器
６０…受光器
Ｐ１〜Ｐ４…投受光信号
Ｄ１〜Ｄ４…受光信号
Ｌ１〜Ｌ４…レーザ光 DESCRIPTION OF SYMBOLS 10 ... Master unit 11a-11d ... Light emitting element 12a-12d ... Drive circuit 13a-13d ... Comparator 14a-14d ... Analog switch 15 ... Control part 20 ... Slave unit 21b-21d ... Light receiving element 22a-22d ... Light receiving amplifier 50 ... Emitter 60 ... Receiver P1-P4 ... Emitter / receiver signal D1-D4 ... Receiver signal L1-L4 ... Laser light

Claims

A plurality of light projecting means for irradiating light toward a predetermined detection area;
A light receiving means capable of receiving light from the detection region;
Projecting and receiving light that sequentially projects the plurality of light projecting means and detects a detection object in the detection area based on a light reception signal corresponding to the amount of light received from the light receiving means in synchronization with the light projection timing of each light projecting means Light emitting / receiving control means for performing the operation;
A plurality of interference light detecting means for detecting interference light based on a light reception signal from the light receiving means at a predetermined detection timing, which is a timing corresponding to each light projecting timing of each of the light projecting means. In the optical axis photoelectric sensor,
While the light projecting / receiving control unit always causes the plurality of light projecting units to sequentially execute a light projecting / receiving operation at every predetermined light projecting timing,
When the interference light is detected by the interference light detection means, only the light projection timing of the light projection means corresponding to the detection timing is shifted to a timing different from the light projection timing of any light projection means. Multi-optical axis photoelectric sensor.

An anti-collision sensor that is disposed in the automatic guided vehicle and detects an obstacle ahead of the automatic guided vehicle in the traveling direction,
A plurality of light projecting means for irradiating light toward the detection area forward in the traveling direction;
A light receiving means capable of receiving the light projected from the light projecting means and reflected by the detection region;
Projecting and receiving light that sequentially projects the plurality of light projecting means and detects a detection object in the detection area based on a light reception signal corresponding to the amount of light received from the light receiving means in synchronization with the light projection timing of each light projecting means Light emitting / receiving control means for performing the operation;
A collision that includes a coherent light detection unit that detects a coherent light based on a light reception signal from the light receiving unit at a predetermined detection timing that corresponds to a light projecting timing of each of the light projecting units. In the prevention sensor,
While the light projecting / receiving control unit always causes the plurality of light projecting units to sequentially execute a light projecting / receiving operation at every predetermined light projecting timing,
When the interference light is detected by the interference light detection means, only the light projection timing of the light projection means corresponding to the detection timing is shifted to a timing different from the light projection timing of any light projection means. Anti-collision sensor.

An anti-collision sensor that is disposed in the automatic guided vehicle and detects an obstacle ahead of the automatic guided vehicle in the traveling direction,
A plurality of light projecting means for irradiating reflected light from the detection area in front of the traveling direction; a plurality of light receiving means provided corresponding to each of the plurality of light projecting means and capable of receiving light from the detection area; The plurality of light projecting units are sequentially projected, and the detection object in the detection region is detected based on a light reception signal corresponding to the amount of light received from the corresponding light receiving unit in synchronization with the light projection timing of each light projecting unit. In a collision prevention sensor comprising a light projection / reception control means for performing a light projection / reception operation to be detected, and an interference light detection means for detecting interference light based on a light reception signal from the corresponding light reception means for each detection timing,
A plurality of light projecting means and light receiving means corresponding to each other, and a part of the corresponding light projecting means and light receiving means, In the machine, the optical axis is arranged near the center of the detection area, and the remaining corresponding light projecting means and light receiving means are arranged in the slave unit with the optical axis directed to the peripheral edge of the detection area,
The light projecting / receiving control means always causes the plurality of light projecting means to sequentially execute the light projecting / receiving operation at every predetermined light projecting timing, while when the interference light detecting means detects the interference light, A collision prevention sensor, wherein only the light projecting timing of the light projecting operation of the light projecting unit corresponding to the light receiving unit in which the interference light is detected is shifted to a timing different from the light projecting timing of any of the light projecting units.