JP2012021822A - Optical phase difference detecting type object detecting sensor - Google Patents

Optical phase difference detecting type object detecting sensor Download PDF

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JP2012021822A
JP2012021822A JP2010158312A JP2010158312A JP2012021822A JP 2012021822 A JP2012021822 A JP 2012021822A JP 2010158312 A JP2010158312 A JP 2010158312A JP 2010158312 A JP2010158312 A JP 2010158312A JP 2012021822 A JP2012021822 A JP 2012021822A
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distance
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phase difference
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JP5740858B2 (en
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Kazumi Honjo
和巳 本荘
Atsushi Okazoe
篤 岡副
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TAKEX LABORATORIES CO Ltd
Takenaka Electronic Industrial Co Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide an optical phase difference detecting type object detecting sensor that can compensates for fluctuations in distance measurement values due to temperature drifting or some other factor in an electric circuit and can detect fluctuations of the distance of a few centimeters.SOLUTION: An optical phase difference detecting type object detecting sensor provided with a light projecting element that projects detection light to a detection area, a light receiving element that receives reflected light from the detection area and generates a light reception signal, distance calculating means that performs distance calculation by detecting a phase difference between the projected light and the received light, and determining means that determines the presence of an object in the detection area is augmented with status correcting means that keeps on monitoring the status of the distance calculating means and, only in the absence of any output from the determining means, corrects the value determined by the determining means on the basis of the result of distance calculation, thereby the result of measuring the distance to a background (such as the floor surface)or a detection threshold is automatically corrected.

Description

本発明は、検知領域の一端に設置され、その検知領域における物体の有無を検知する光位相差検出式の物体検知センサに関する。 The present invention relates to an optical phase difference detection type object detection sensor that is installed at one end of a detection region and detects the presence or absence of an object in the detection region.

光位相差検出式センサ(例えば、特許文献1参照)は、投光波と受光波の位相差を検出して、被検知物体までの距離を測定している。これは、上記位相差が被検知物体との距離に比例することを利用したものである。そのため、光位相差検出式センサは、原理的に温度等の影響を受けにくく、被検知物体の色の変化にも強い。 An optical phase difference detection sensor (for example, refer to Patent Document 1) detects a phase difference between a light projection wave and a light reception wave, and measures a distance to an object to be detected. This utilizes the fact that the phase difference is proportional to the distance to the detected object. For this reason, the optical phase difference detection type sensor is in principle less susceptible to temperature and the like, and is resistant to changes in the color of the detected object.

しかし、電気回路の温度ドリフトにより、距離測定値が変動するため、数センチ単位の距離変動を検出することは困難である。光位相差検出式の距離測定装置において、レーザーダイオードの発光強度が温度により変化してしまう問題の対策として、温度測定記憶手段と各温度に対する温度補正係数を用いて、距離計測能力を補正することも考えられていた(例えば、特許文献2参照)。 However, since the distance measurement value varies due to the temperature drift of the electric circuit, it is difficult to detect a distance variation of several centimeters. In the optical phase difference detection type distance measuring device, as a countermeasure against the problem that the light emission intensity of the laser diode changes depending on the temperature, the distance measuring ability is corrected using the temperature measurement storage means and the temperature correction coefficient for each temperature. (For example, refer to Patent Document 2).

特開2005−325537号公報JP 2005-325537 A

特開平09−318737号公報JP 09-318737 A

しかし、この方法では、温度測定手段、温度記憶手段等が必要となり、構造が複雑となる。また、各温度に対する温度補正係数を決めなければならず、そのためのデータ採取、分析、設定といった諸作業が必要となり、開発コストが増大するといった問題がある。また、温度ドリフトによる距離測定値の変動度合いは、背景(床面等)の反射率により異なることが判っており、温度補正係数は、一つに特定することはできない。 However, this method requires temperature measuring means, temperature storage means, etc., and the structure becomes complicated. In addition, a temperature correction coefficient for each temperature must be determined, and various operations such as data collection, analysis, and setting are required, which increases the development cost. Further, it is known that the degree of fluctuation of the distance measurement value due to temperature drift varies depending on the reflectance of the background (floor surface, etc.), and the temperature correction coefficient cannot be specified as one.

本発明は上記問題点を解決するためになされたものであり、その目的は、回路構成や構造を複雑にすることなく、どのような場所に設置しても、数センチ単位まで正確に、物体の有無を検知することができる光位相差検出式の物体検知センサを提供することにある。 The present invention has been made to solve the above-mentioned problems, and the object thereof is to accurately detect objects up to several centimeters regardless of where they are installed without complicating the circuit configuration and structure. An object of the present invention is to provide an optical phase difference detection type object detection sensor capable of detecting the presence or absence of light.

上記課題を解決するために本発明は、(1)検知領域における物体の有無を検知するセンサであって、検知領域に向けて検出光を投光する投光素子と、前記検知領域からの反射光を受光して受光信号を生成する受光素子と、投光した光と、受光した光との位相差を検出し距離計算をおこなう距離算出手段と、前記検知領域内に物体が有ると判定する判定手段と、距離算出手段の状態を監視し続け、判定手段からの出力が存在していない時にのみ、距離算出結果に基づき判定手段の判定値を補正する状態補正手段とを備えていることを特徴とする光位相差検出式の物体検知センサを提供するものである。 In order to solve the above-described problems, the present invention provides (1) a sensor for detecting the presence or absence of an object in a detection area, a light projecting element that projects detection light toward the detection area, and a reflection from the detection area. A light receiving element that receives light and generates a light reception signal, distance calculation means that detects a phase difference between the projected light and the received light, and performs distance calculation, and determines that an object is present in the detection region A determination unit and a state correction unit that continuously monitors the state of the distance calculation unit and corrects the determination value of the determination unit based on the distance calculation result only when there is no output from the determination unit. An object detection sensor of an optical phase difference detection type that is characterized is provided.

また本発明は、上記構成において、(2)前記状態補正手段は、時間T1よりも長い時間判定手段からの出力が存在していないことを受けて、その間の時間T2(T2≦T1)だけ距離算出手段の状態を抽出し、その平均値を記憶する補正値記憶手段と、判定手段からの出力が発生すると同時に、直近の時間T2の距離算出手段の抽出値を破棄する状態監視手段とを備え、前記補正値記憶手段の値を、距離算出結果とすることを特徴とする光位相差検出式の物体検知センサを提供するものである。 Further, the present invention provides the above configuration, wherein (2) the state correction means is a distance by a time T2 (T2 ≦ T1) during the period when there is no output from the time determination means longer than the time T1. A correction value storage means for extracting the state of the calculation means and storing the average value thereof, and a state monitoring means for discarding the extracted value of the distance calculation means at the latest time T2 at the same time as the output from the determination means is generated. An object detection sensor of an optical phase difference detection type is provided in which the value of the correction value storage means is used as a distance calculation result.

また本発明は、上記構成(2)において、(3)前記状態監視手段は、時間T1よりも長い時間判定手段からの出力が存在していないことを受けて、その間の時間T2(T2≦T1)だけ距離算出手段の状態を抽出し、その平均値が記憶済みの値と比較して所定値以上の変動を含む場合にのみ記憶内容を更新することを特徴とする光位相差検出式の物体検知センサを提供するものである。 Further, according to the present invention, in the configuration (2), (3) the state monitoring means receives the fact that there is no output from the time determination means longer than the time T1, and the time T2 (T2 ≦ T1) ), The state of the distance calculation means is extracted, and the stored content is updated only when the average value includes a fluctuation greater than or equal to a predetermined value compared to the stored value. A detection sensor is provided.

また本発明は、上記構成(2)において、(4)前記距離算出手段は、前記判定手段の応答速度に相当する距離計算速度と、前記判定手段の応答速度と異なる距離計算速度とを備え、前記状態補正手段は、前記2種類の距離計算速度による距離算出結果を、それぞれに設定した物体の有無を判定する判定とは異なる判定値に基づき判定し、前記補正値記憶手段の値を更新していくことを特徴とする光位相差検出式の物体検知センサを提供するものである。 Further, in the configuration (2), the present invention includes (4) the distance calculation means including a distance calculation speed corresponding to the response speed of the determination means and a distance calculation speed different from the response speed of the determination means, The state correction unit determines a distance calculation result based on the two types of distance calculation speeds based on a determination value different from the determination for determining the presence / absence of an object, and updates the value of the correction value storage unit. It is an object of the present invention to provide an optical phase difference detection type object detection sensor.

また本発明は、上記構成(4)において、(5)判定手段の応答速度と異なる距離計算速度に基づき抽出された距離算出値が、前記補正値記憶手段の値を、大きく変化させる場合には、直近の距離算出手段の抽出値を破棄することを特徴とする光位相差検出式の物体検知センサを提供するものである。 In the configuration (4), when the distance calculation value extracted based on the distance calculation speed different from the response speed of the determination means greatly changes the value of the correction value storage means in the configuration (4). The object detection sensor of the optical phase difference detection type is characterized in that the extracted value of the latest distance calculation means is discarded.

上記のように構成された本発明の物体検知センサによれば、通常動作時に距離測定を継続し、検出物体が存在しないと判断したときのみ、自動的に背景(床面等)までの距離測定結果の補正、もしくは、検出閾値の補正をおこなうので、数センチ単位まで正確に、物体の有無を検知することができる。検知領域を通過する物体(検出対象としない物体)による補正値の変動や、想定外の補正値の変動を除去する様にしたので、物体の有無検知性能を、適切に維持することができる。温度測定手段や温度記憶手段を必要としないので、回路構成、製品構造が複雑化せず、コストが抑えられる。距離算出結果に基づき補正をおこなう方式であるので、背景(床面等)の反射率により異なる温度ドリフトによる距離測定値の変動度合いの違い、個体差による距離測定値の変動度合いの違い、経年変化による距離測定値の変動、光学系の汚れによる距離測定値の変動等あらゆる変動に対応することができる。 According to the object detection sensor of the present invention configured as described above, distance measurement is continued during normal operation, and only when it is determined that there is no detected object, distance measurement to the background (floor surface, etc.) is automatically performed. Since the result is corrected or the detection threshold value is corrected, the presence or absence of an object can be accurately detected up to several centimeters. Since fluctuations in correction values due to objects passing through the detection area (objects not to be detected) and fluctuations in unexpected correction values are eliminated, the object presence / absence detection performance can be appropriately maintained. Since no temperature measurement means or temperature storage means is required, the circuit configuration and product structure are not complicated, and costs can be reduced. Since the correction is based on the distance calculation result, the difference in the distance measurement value due to temperature drift varies depending on the reflectivity of the background (floor surface, etc.), the difference in the distance measurement variation due to individual differences, and the secular change It is possible to deal with all kinds of fluctuations, such as fluctuations in distance measurement values due to light and fluctuations in distance measurement values due to contamination of the optical system.

図1は、本発明の光位相差検出式の物体検知センサの構成を示すブロック図である。FIG. 1 is a block diagram showing a configuration of an optical phase difference detection type object detection sensor of the present invention. 図2は、本発明の光位相差検出式の物体検知センサの設置状態と動作状態を示した説明図である。FIG. 2 is an explanatory diagram showing an installation state and an operation state of the optical phase difference detection type object detection sensor of the present invention. 図3は状態補正手段がおこなう距離算出手段の状態抽出に関わる時間T1及びT2の説明図である。FIG. 3 is an explanatory diagram of the times T1 and T2 related to the state extraction of the distance calculation means performed by the state correction means. 図4は、距離算出手段の距離計算速度の違いによる、距離算出手段の状態の差を示した説明図である。FIG. 4 is an explanatory diagram showing a difference in the state of the distance calculation means due to a difference in the distance calculation speed of the distance calculation means. 図5は、温度ドリフト以外の補正値の変動状態を示した説明図である。FIG. 5 is an explanatory diagram showing a fluctuation state of the correction value other than the temperature drift. 図6は、本発明の光位相差検出式の物体検知センサの動作状態を示したフローチャートである。FIG. 6 is a flowchart showing an operation state of the optical phase difference detection type object detection sensor of the present invention.

以下、図面を参照して本発明の実施形態について説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図1は、本発明の光位相差検出式の物体検知センサの構成を示すブロック図である。
物体検知センサ1内には、検出光を投光する投光素子11、検知領域からの反射光を受光して受光信号を生成する受光素子12、投光した光と、受光した光との位相差を検出し距離計算をおこなう距離算出手段13、検知領域内に物体が有ると判定する判定手段15、距離算出手段の状態を監視し続け、判定手段からの出力が存在していない時にのみ、距離算出結果に基づき判定手段の判定値を補正する状態補正手段14、検知信号を発する出力手段16を備えている。
FIG. 1 is a block diagram showing a configuration of an optical phase difference detection type object detection sensor of the present invention.
In the object detection sensor 1, a light projecting element 11 for projecting detection light, a light receiving element 12 for receiving reflected light from the detection area and generating a light reception signal, the position of the projected light and the received light The distance calculation means 13 for detecting the phase difference and calculating the distance, the determination means 15 for determining that there is an object in the detection area, and continuously monitoring the state of the distance calculation means, and only when there is no output from the determination means, A state correction unit 14 that corrects the determination value of the determination unit based on the distance calculation result, and an output unit 16 that generates a detection signal are provided.

図2は、本発明の光位相差検出式の物体検知センサの設置状態と動作状態を示した説明図である。(A)は、設置状態を示す側面図であり、(B)は、距離測定結果の変動状態を、物体検出の閾値との関係を含め説明したタイムチャートである。Wは天井、Gは床であり、1は本発明の物体検知センサである。 FIG. 2 is an explanatory diagram showing an installation state and an operation state of the optical phase difference detection type object detection sensor of the present invention. (A) is a side view which shows an installation state, (B) is a time chart explaining the fluctuation | variation state of a distance measurement result including the relationship with the threshold value of an object detection. W is a ceiling, G is a floor, and 1 is an object detection sensor of the present invention.

物体検知センサ1の真下に検知領域が形成され、投光素子11から投光された光が、対象物に当り、そこで反射して戻ってきた反射光を受光素子12で受光している。受光素子の出力をもとに受光信号を生成して、投光した光と受光した光との位相差を検出し、距離算出手段13で距離計算をおこなう。 A detection region is formed directly below the object detection sensor 1, and the light projected from the light projecting element 11 hits the object, and the reflected light that is reflected and returned there is received by the light receiving element 12. A light reception signal is generated based on the output of the light receiving element, the phase difference between the projected light and the received light is detected, and the distance calculation means 13 calculates the distance.

この種のセンサは、設置時や電源投入時に、検知領域の背景となる床面までの距離と、検知領域内の床面におかれた所定の高さの被検知物体までの距離を測定し、内部回路に記憶させる、いわゆるティーチングという操作をおこなう。ここで、床面までの距離をL1、所定の高さの被検知物体までの距離をL2とする。ティーチング時に使用する被検知物体の高さを10センチメートルとすると、それよりも大きな(10センチメートルよりも背の高い)物体が検知領域内に存在すると、物体検知センサから検知信号が発せられる様に設定される。ティーチング時に、L1を測定すると、自動的にL2が設定される様にしているものもある。 This type of sensor measures the distance to the floor, which is the background of the detection area, and the distance to the object to be detected on the floor in the detection area when installed or powered on. Then, the so-called teaching operation is performed to store in the internal circuit. Here, the distance to the floor surface is L1, and the distance to the object to be detected having a predetermined height is L2. If the height of the object to be detected used for teaching is 10 centimeters, and a larger object (that is taller than 10 centimeters) is present in the detection region, a detection signal is generated from the object detection sensor. Set to In some cases, L2 is automatically set when L1 is measured during teaching.

図2(B)のタイムチャートの縦軸は、距離算出結果に対応した信号出力値であり、横軸は時間である。測定距離が短いほどプラス側に変動するように示されている。L2は、検知領域内に物体が有ると判定する判定手段の閾値である。実線は、信号を表しており、閾値L2を超えると、物体検知センサから検知信号が発せられる。時間(イ)、(ハ)は、検知物体なし、時間(ロ)、(ニ)は、検知物体ありの状態を示している。 The vertical axis of the time chart in FIG. 2B is a signal output value corresponding to the distance calculation result, and the horizontal axis is time. It is shown that the shorter the measurement distance, the more positive the fluctuation. L2 is a threshold value of a determination unit that determines that there is an object in the detection area. A solid line represents a signal. When the threshold value L2 is exceeded, a detection signal is emitted from the object detection sensor. Times (A) and (C) show no detected object, and times (B) and (D) show a state with a detected object.

時間(ハ)に示されている様に、物体検知センサから床面までの距離は一定であるのにもかかわらず、距離算出結果に対応した信号出力値が変動する場合がある。これは、電気回路の温度ドリフトによるものであり、周囲温度が年中一定な特殊環境での使用を除き、不可避の問題である。 As shown in the time (c), the signal output value corresponding to the distance calculation result may fluctuate even though the distance from the object detection sensor to the floor surface is constant. This is due to temperature drift of the electric circuit, and is an inevitable problem except for use in a special environment where the ambient temperature is constant throughout the year.

L2を10センチメートルに相当する閾値と設定している場合、床面までの距離算出結果が温度により変動すると、背の高さが5センチメートルの物体を検知してしまったり、その反対に、背の高さが15センチメートルの物体であっても検知しなくなったりする現象が発生してしまう。特に、光位相差検出式の物体検知センサを、急病によって倒れてしまった人間の検知を目的として使用する際には、このような検出感度の変動は許されない。 When L2 is set as a threshold value corresponding to 10 centimeters, if the calculation result of the distance to the floor fluctuates due to temperature, an object with a height of 5 centimeters may be detected. Even if the height of the object is 15 centimeters, a phenomenon may occur in which the object is not detected. In particular, when the optical phase difference detection type object detection sensor is used for the purpose of detecting a human who has fallen due to a sudden illness, such variation in detection sensitivity is not allowed.

そこで、時間T1(たとえば30秒)ごとに区切り、その間の限られた時間T2(例えば1秒)の間の距離算出結果の平均値をL1´として記憶させ、このL1´を、ティーチング時に設定したL1と入れ替え、同時にこの変動分に相当するだけ判定手段の閾値L2をシフトさせるか、距離算出結果の値を変動分だけシフトさせれば、温度ドリフトに対する補正をおこなうことができると考えた。この処理は、結果として判定手段の判定値を補正することにつながる。 Therefore, it is divided every time T1 (for example, 30 seconds), the average value of the distance calculation results during the limited time T2 (for example, 1 second) is stored as L1 ′, and this L1 ′ is set at teaching It was considered that correction for temperature drift can be performed by replacing L1 and simultaneously shifting the threshold value L2 of the determination means by an amount corresponding to the variation or shifting the value of the distance calculation result by the variation. This process leads to correcting the determination value of the determination means as a result.

タイムチャート中の、1回目、2回目のT1区間では、検出物体なしの判定であり、それぞれのT2区間の距離算出結果の平均値をL1´を補正値として採用する。3回目のT1区間では、後半において検出物体ありとなっているので、この区間のT2区間の距離算出結果の平均値は、破棄する。このような処理をおこなうことにより、検知物体ありの状態だけでなく、検知物体ありの状態へ移行する直前の不安定な距離算出結果による補正処理を回避できる。 In the first and second T1 sections in the time chart, it is determined that there is no detected object, and an average value of distance calculation results in each T2 section is adopted as a correction value. In the third T1 section, since there is a detection object in the second half, the average value of the distance calculation results in the T2 section of this section is discarded. By performing such processing, it is possible to avoid correction processing based on an unstable distance calculation result immediately before shifting to a state with a detected object as well as a state with a detected object.

図3は状態補正手段がおこなう距離算出手段の状態抽出に関わる時間T1及びT2の状態を示した説明図である。精度良く距離算出をおこなうために、距離算出手段の状態抽出に関わる時間を長くする必要がある。この図に示すような時間T1(検知物体なしの状態の時間)を通して距離算出結果の平均を採り、補正値として採用することも考えられるが、そうすると、T1の初期と後期の部分の測定値が、床面からの距離と異なっているため、T1区間の平均値が、床面との距離の正確な補正値とはならない。これは、距離算出を、移動平均、連続一致のディレイ処理等を介して処理し、距離測定を確実にしているためである。つまり、距離算出手段から得られる信号は、応答が遅くなっているからである。正確な補正値とするための工夫として、時間T1の中に、T2を設け、T2の間の距離算出結果の平均値をとるようにしている。 FIG. 3 is an explanatory diagram showing the states at times T1 and T2 related to the state extraction of the distance calculating means performed by the state correcting means. In order to perform distance calculation with high accuracy, it is necessary to lengthen the time relating to the state extraction of the distance calculation means. It is conceivable that the average of distance calculation results is taken through time T1 (time when there is no sensing object) as shown in this figure and used as a correction value. Since the distance from the floor surface is different, the average value in the T1 section is not an accurate correction value for the distance from the floor surface. This is because distance calculation is processed through moving average, continuous matching delay processing, and the like to ensure distance measurement. That is, the signal obtained from the distance calculating means has a slow response. As a device for obtaining an accurate correction value, T2 is provided in time T1, and an average value of distance calculation results between T2 is taken.

図4は、距離算出手段の距離計算速度の違いによる、距離算出手段の差を示した説明図である。距離算出を、移動平均、連続一致のディレイ処理等を介して処理し、距離測定を確実にしているために、距離算出手段から得られる信号は、応答が遅くなっているが、応答速度以上に速いスピードで物体が検知領域を横切ると、応答の速い距離算出処理を経た信号は、図4の破線に示すようになり、判定手段の判定値を超えている。距離算出手段から得られる信号は実線で示すようになり、検出物体なしの判定となるが、このときの距離算出結果の平均値は、床面との距離の正確な補正値とはならない。 FIG. 4 is an explanatory diagram showing the difference in the distance calculation means due to the difference in the distance calculation speed of the distance calculation means. The distance calculation is processed through moving average, continuous coincidence delay processing, etc., and the distance measurement is ensured, so the signal obtained from the distance calculation means has a slow response, but it exceeds the response speed. When an object crosses the detection area at a high speed, a signal that has undergone a quick response distance calculation process is as shown by a broken line in FIG. 4 and exceeds the determination value of the determination means. The signal obtained from the distance calculation means is indicated by a solid line, and it is determined that there is no detection object. However, the average value of the distance calculation result at this time is not an accurate correction value for the distance to the floor surface.

応答の速い距離算出処理を経た信号が、判定手段の判定値を超えた場合には、この間の距離算出結果の平均値は、破棄するような処理をおこなう。これにより、応答速度以上に速いスピードで横切る検知物体による誤った補正処理を回避できる。図4に示す例では、応答の速い距離算出処理の応答速度を10ms とし、距離算出手段から得られる信号の応答速度は、100msとした。 When the signal that has undergone the quick distance calculation processing exceeds the determination value of the determination means, the average value of the distance calculation results during this time is discarded. As a result, it is possible to avoid erroneous correction processing due to the detected object crossing at a speed faster than the response speed. In the example shown in FIG. 4, the response speed of the quick distance calculation process is 10 ms, and the response speed of the signal obtained from the distance calculation means is 100 ms.

図5は、温度ドリフト以外の補正値の変動状態を示した説明図である。温度ドリフトは、検知器の周囲温度、検知器の内部回路の発熱等により発生するものであり、急激な変化を生じさせるものではない。このため図5に示すような変動は、温度ドリフト以外のいわゆる想定外の変動として、補正判定から取り除く必要がある。たとえば、1回目のT1区間内のT2区間の距離算出結果の平均値L1´が、それ以前の距離算出結果と比較して、床面の距離換算で5センチメートル以下の変動幅である場合には、これを補正値として採用する。2回目のT1区間内のT2区間の距離算出結果の平均値L1´が、それ以前の距離算出結果と比較して、床面の距離換算で5センチメートル以下の変動幅である場合には、これを再び補正値として採用する。これを繰り返し、N回目のT1区間内のT2区間の距離算出結果の平均値L1´が、それ以前の距離算出結果と比較して、床面の距離換算で5センチメートルの変動幅を超える場合には、N回目のT1区間内のT2区間の距離算出結果の平均値は、破棄する。このような処理をおこなうことにより温度ドリフト以外の補正値の変動を除去することができる。 FIG. 5 is an explanatory diagram showing a fluctuation state of the correction value other than the temperature drift. The temperature drift is caused by the ambient temperature of the detector, heat generation of the internal circuit of the detector, etc., and does not cause a sudden change. Therefore, it is necessary to remove the fluctuation as shown in FIG. 5 from the correction determination as a so-called unexpected fluctuation other than the temperature drift. For example, when the average value L1 ′ of the distance calculation result of the T2 section in the first T1 section is a fluctuation range of 5 centimeters or less in terms of the distance of the floor surface compared to the distance calculation result before that Adopts this as a correction value. When the average value L1 ′ of the distance calculation result of the T2 section in the second T1 section is a fluctuation range of 5 centimeters or less in terms of the distance of the floor surface compared with the distance calculation result before that, This is again adopted as a correction value. When this is repeated, the average value L1 ′ of the distance calculation results in the T2 section in the Nth T1 section exceeds the fluctuation range of 5 centimeters in terms of the distance of the floor surface compared to the previous distance calculation results The average value of the distance calculation results in the T2 section in the Nth T1 section is discarded. By performing such processing, fluctuations in correction values other than temperature drift can be eliminated.

次に、本発明の光位相差検出式の物体検知センサの動作を、電源投入から順を追って説明する。ここでは、距離算出結果の値を変動分だけシフトさせ、温度ドリフトに対する補正をおこなう方式について説明する。電源をオンすると、ティーチングを開始し、L1の値を設定する。L1の値は、検知器から背景となる床面までの距離である。続いて、L2の値が設定される。高さ10センチメートル以上の物体を検知する様にするため、L2は、L1よりも10センチメートルだけ小さな値に設定される。これらの設定が完了すると、距離算出手段の出力の監視を開始する。図6は、本発明の光位相差検出式の物体検知センサの動作状態を示したフローチャートであり、ティーチング終了後の動作状態を示している。 Next, the operation of the optical phase difference detection type object detection sensor of the present invention will be described step by step from power-on. Here, a method for correcting the temperature drift by shifting the value of the distance calculation result by the variation will be described. When the power is turned on, teaching is started and the value of L1 is set. The value of L1 is the distance from the detector to the background floor. Subsequently, the value of L2 is set. In order to detect an object having a height of 10 centimeters or more, L2 is set to a value smaller by 10 centimeters than L1. When these settings are completed, monitoring of the output of the distance calculation means is started. FIG. 6 is a flowchart showing an operation state of the object detection sensor of the optical phase difference detection type according to the present invention, and shows an operation state after the teaching is completed.

ステップS001で距離算出手段の出力の監視を開始し、ステップS002では、判定手段の応答速度に相当する距離計算速度に基づき距離データを計算する。そして、その平均化処理を行い、その結果D1を一時的に記憶する。ステップS003では、判定手段の応答速度よりも速い距離計算速度に基づき距離データを計算し、その平均化処理を行い、その結果D2を一時的に記憶する。ステップS004では、D1の値がL3の値を下回っているかどうかを監視し、下回っておれば、ステップS005に進む。L3は、物体の有無を判定する判定値L2とは異なる値であり、ドリフト補正要否を判定する判定閾値である。 In step S001, monitoring of the output of the distance calculation means is started, and in step S002, distance data is calculated based on a distance calculation speed corresponding to the response speed of the determination means. Then, the averaging process is performed, and the result D1 is temporarily stored. In step S003, the distance data is calculated based on the distance calculation speed faster than the response speed of the determination means, the averaging process is performed, and the result D2 is temporarily stored. In step S004, it is monitored whether or not the value of D1 is lower than the value of L3, and if it is lower, the process proceeds to step S005. L3 is a value different from the determination value L2 for determining the presence or absence of an object, and is a determination threshold value for determining whether or not drift correction is necessary.

ステップS005では、D2の値がL4の値を下回っているかどうか監視し、下回っておれば、ステップS006に進む。L4は、物体の有無を判定する判定値L2とは異なる判定値であり、L3の値の60%から70%の大きさに設定されたドリフト補正要否を判定する判定閾値である。ステップS006では、時間計測用のカウンタをインクリメントする。ステップS004とステップS005で、D1の値とD2の値がそれぞれの判定閾値以上となった場合には、ステップS012で、時間計測用のカウンタをリセットし、時間計測をゼロ秒に戻す。 In step S005, it is monitored whether the value of D2 is lower than the value of L4. If it is lower, the process proceeds to step S006. L4 is a determination value that is different from the determination value L2 for determining the presence / absence of an object, and is a determination threshold value for determining whether or not drift correction is necessary, which is set to a value between 60% and 70% of the value of L3. In step S006, a time measurement counter is incremented. In step S004 and step S005, when the value of D1 and the value of D2 are equal to or greater than the respective determination threshold values, the time measurement counter is reset in step S012, and the time measurement is returned to zero seconds.

ステップS007では、カウンタの値がゼロであるかどうかを監視し、ゼロであれば、ステップS013に進み、補正用データD3をゼロにリセットする。D3は、平均化処理された距離データとL1の値との差に相当する値であり、補正用データとして平均化されて記憶されている。ステップS007で、カウンタの値がゼロでなければ、ステップS008へ進み、カウンタの値がTaよりも大きくTbよりも小さいかどうか(時間T2であるか)が判定される。カウンタの値がこの範囲に入っていると、ステップS014に進み、補正用データD3を平均化し、記憶する。カウンタの値がこの範囲に入っていなければ、ステップS009に進む。ステップS009では、カウンタの値がT1を超えたかどうかを監視し、超えたら、ドリフト補正値Dhを補正用データD3に更新し、カウンタ値をゼロにリセットする。 In step S007, it is monitored whether the value of the counter is zero. If it is zero, the process proceeds to step S013, and the correction data D3 is reset to zero. D3 is a value corresponding to a difference between the averaged distance data and the value of L1, and is averaged and stored as correction data. If the value of the counter is not zero in step S007, the process proceeds to step S008, and it is determined whether the value of the counter is larger than Ta and smaller than Tb (time T2). If the value of the counter is within this range, the process proceeds to step S014, and the correction data D3 is averaged and stored. If the counter value is not within this range, the process proceeds to step S009. In step S009, it is monitored whether or not the counter value exceeds T1, and if it exceeds, the drift correction value Dh is updated to the correction data D3, and the counter value is reset to zero.

カウンタの値がT1を超えていなければ、ステップS010へ進み、補正距離データDが演算される。補正距離データDは、距離データD1、距離データD2のどちらかの値を基に演算される。そして、ステップS011で補正距離データを基に出力判定がおこなわれる。以上のステップS001からステップS011までの一連の動作を、約7mSで実行する。ステップS001とステップS002で実行される距離データの平均化処理は、10回分(約70mS)のデータの平均値を計算し順次更新して一時的に記憶している。時間T1の間、継続して、D1とD2がドリフト補正判定閾値を下回っていれば、その間の時間T2に取得した補正用データD3を、ドリフト補正値Dhとして順次更新し続けることになる。 If the value of the counter does not exceed T1, the process proceeds to step S010, and corrected distance data D is calculated. The corrected distance data D is calculated based on one of the distance data D1 and the distance data D2. In step S011, output determination is performed based on the corrected distance data. A series of operations from step S001 to step S011 is executed at about 7 mS. In the distance data averaging process executed in steps S001 and S002, the average value of data for 10 times (about 70 mS) is calculated, sequentially updated, and temporarily stored. If D1 and D2 continue to fall below the drift correction determination threshold during time T1, the correction data D3 acquired at time T2 during that time is continuously updated as the drift correction value Dh.

図6のフローチャートに示した実施例は、温度ドリフトが発生していない状況下でも、ドリフト補正値Dhを更新し続けるものであるが、補正用データD3が、所定の値に満たない場合には、ドリフト補正をしないというステップを組み込んで、所定値以上の温度ドリフトのみを補正対象としても本発明の効果は発揮される。 In the embodiment shown in the flowchart of FIG. 6, the drift correction value Dh is continuously updated even in a situation where no temperature drift occurs. However, when the correction data D3 is less than a predetermined value, The effect of the present invention can also be achieved by incorporating a step of not performing drift correction and only correcting a temperature drift of a predetermined value or more.

本発明は、光位相差検出式の物体検知センサだけでなく、超音波を用いた距離測定装置他、ティーチング操作を伴い物体検知を行う装置にて利用することができる。 The present invention can be used not only in an optical phase difference detection type object detection sensor but also in a distance measurement device using ultrasonic waves and other devices that perform object detection with a teaching operation.

1 光位相差検出式の物体検知センサ
11 投光素子
12 受光素子
13 距離検出手段
14 状態補正手段
15 判定手段
16 出力手段
L1 ティーチングにて記憶した背景までの距離
L2 検知領域内に物体が有ると判定する距離
W 天井
G 床
DESCRIPTION OF SYMBOLS 1 Optical phase difference detection type object detection sensor 11 Light projection element 12 Light receiving element 13 Distance detection means 14 State correction means 15 Determination means 16 Output means L1 Distance to the background memorize | stored by teaching L2 When an object exists in a detection area Judgment distance W Ceiling G Floor

Claims (5)

検知領域における物体の有無を検知するセンサであって、検知領域に向けて検出光を投光する投光素子と、前記検知領域からの反射光を受光して受光信号を生成する受光素子と、投光した光と、受光した光との位相差を検出し距離計算をおこなう距離算出手段と、前記検知領域内に物体が有ると判定する判定手段と、距離算出手段の状態を監視し続け、判定手段からの出力が存在していない時にのみ、距離算出結果に基づき判定手段の判定値を補正する状態補正手段とを備えていることを特徴とする光位相差検出式の物体検知センサ。 A sensor for detecting the presence or absence of an object in the detection region, a light projecting element that projects detection light toward the detection region, a light receiving element that receives reflected light from the detection region and generates a light reception signal, The distance calculation means for detecting the phase difference between the projected light and the received light and calculating the distance, the determination means for determining that there is an object in the detection area, and continuously monitoring the status of the distance calculation means, An optical phase difference detection type object detection sensor comprising: a state correction unit that corrects a determination value of the determination unit based on a distance calculation result only when there is no output from the determination unit. 前記状態補正手段は、時間T1よりも長い時間判定手段からの出力が存在していないことを受けて、その間の時間T2(T2≦T1)だけ距離算出手段の状態を抽出し、その平均値を記憶する補正値記憶手段と、判定手段から出力が発生するのを受けて、直近の時間T2の距離算出手段の抽出値を破棄する状態監視手段とを備え、前記補正値記憶手段の値を、距離算出結果とすることを特徴とする請求項1に記載の光位相差検出式の物体検知センサ。 The state correction means extracts the state of the distance calculation means for the time T2 (T2 ≦ T1) during that time, in response to the absence of the output from the time determination means longer than the time T1, and calculates the average value thereof. A correction value storage means for storing, and a state monitoring means for discarding the extracted value of the distance calculation means at the most recent time T2 in response to the output generated from the determination means, the value of the correction value storage means being The optical phase difference detection type object detection sensor according to claim 1, wherein a distance calculation result is obtained. 前記状態監視手段は、時間T1よりも長い時間判定手段からの出力が存在していないことを受けて、その間の時間T2(T2≦T1)だけ距離算出手段の状態を抽出し、その平均値が記憶済みの値と比較して所定値以上の変動を含む場合にのみ記憶内容を更新することを特徴とする請求項2に記載の光位相差検出式の物体検知センサ。 In response to the absence of the output from the time determination means longer than the time T1, the state monitoring means extracts the state of the distance calculation means for the time T2 (T2 ≦ T1) during that time, and the average value is 3. The optical phase difference detection type object detection sensor according to claim 2, wherein the stored content is updated only when a variation greater than a predetermined value is included in comparison with the stored value. 前記距離算出手段は、前記判定手段の応答速度に相当する距離計算速度と、前記判定手段の応答速度と異なる距離計算速度とを備え、前記状態補正手段は、前記2種類の距離計算速度による距離算出結果を、それぞれに設定した物体の有無を判定する判定とは異なる判定値に基づき判定し、前記補正値記憶手段の値を更新していくことを特徴とする請求項2に記載の光位相差検出式の物体検知センサ。 The distance calculation means includes a distance calculation speed corresponding to the response speed of the determination means and a distance calculation speed different from the response speed of the determination means, and the state correction means is a distance based on the two types of distance calculation speeds. 3. The light level according to claim 2, wherein the calculation result is determined based on a determination value different from the determination for determining the presence / absence of the set object, and the value of the correction value storage means is updated. Phase detection type object detection sensor. 判定手段の応答速度と異なる距離計算速度に基づき抽出された距離算出値が、前記補正値記憶手段の値を、大きく変化させる場合には、直近の距離算出手段の抽出値を破棄することを特徴とする請求項4に記載の光位相差検出式の物体検知センサ。 When the distance calculation value extracted based on the distance calculation speed different from the response speed of the determination means greatly changes the value of the correction value storage means, the extracted value of the latest distance calculation means is discarded. The optical phase difference detection type object detection sensor according to claim 4.
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CN110927736A (en) * 2018-09-19 2020-03-27 发那科株式会社 Object monitoring system with distance measuring device
CN111198384A (en) * 2018-10-31 2020-05-26 发那科株式会社 Object monitoring system with distance measuring device

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0194283A (en) * 1987-10-07 1989-04-12 Nippon Air Brake Co Ltd Human body detector
JPH08105973A (en) * 1994-10-03 1996-04-23 Nissan Motor Co Ltd Inter-vehicle distance measuring device
JPH08262138A (en) * 1995-03-24 1996-10-11 Asahi Optical Co Ltd Instrument for measuring distance by light wave and light quantity control method therefor
JPH09116411A (en) * 1995-10-23 1997-05-02 Keyence Corp Photoelectric switch
JPH09284117A (en) * 1996-04-17 1997-10-31 Omron Corp Detection switch
JPH1130666A (en) * 1997-04-30 1999-02-02 Sick Ag Acting method of photoelectron sensor
JPH1144760A (en) * 1997-07-25 1999-02-16 Secom Co Ltd Human body detector
JP2005283473A (en) * 2004-03-30 2005-10-13 Nec Tokin Corp Ultrasonic position detector
JP2006046961A (en) * 2004-07-30 2006-02-16 Matsushita Electric Works Ltd Human body sensor
JP2010151680A (en) * 2008-12-25 2010-07-08 Toyota Motor Corp Device and method for calibrating sensor
JP2010169525A (en) * 2009-01-22 2010-08-05 Topcon Corp Optical distance measuring method and optical distance measuring device

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0194283A (en) * 1987-10-07 1989-04-12 Nippon Air Brake Co Ltd Human body detector
JPH08105973A (en) * 1994-10-03 1996-04-23 Nissan Motor Co Ltd Inter-vehicle distance measuring device
JPH08262138A (en) * 1995-03-24 1996-10-11 Asahi Optical Co Ltd Instrument for measuring distance by light wave and light quantity control method therefor
JPH09116411A (en) * 1995-10-23 1997-05-02 Keyence Corp Photoelectric switch
JPH09284117A (en) * 1996-04-17 1997-10-31 Omron Corp Detection switch
JPH1130666A (en) * 1997-04-30 1999-02-02 Sick Ag Acting method of photoelectron sensor
JPH1144760A (en) * 1997-07-25 1999-02-16 Secom Co Ltd Human body detector
JP2005283473A (en) * 2004-03-30 2005-10-13 Nec Tokin Corp Ultrasonic position detector
JP2006046961A (en) * 2004-07-30 2006-02-16 Matsushita Electric Works Ltd Human body sensor
JP2010151680A (en) * 2008-12-25 2010-07-08 Toyota Motor Corp Device and method for calibrating sensor
JP2010169525A (en) * 2009-01-22 2010-08-05 Topcon Corp Optical distance measuring method and optical distance measuring device

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014137340A (en) * 2013-01-18 2014-07-28 Sanden Corp Sensor unit, automatic selling machine, and human sensor identification method by human sensor
WO2020013139A1 (en) * 2018-07-11 2020-01-16 株式会社デンソー Signal processing device
JP2020008489A (en) * 2018-07-11 2020-01-16 株式会社デンソー Signal processing device
JP7010161B2 (en) 2018-07-11 2022-02-10 株式会社デンソー Signal processing equipment
CN110927736A (en) * 2018-09-19 2020-03-27 发那科株式会社 Object monitoring system with distance measuring device
CN110927736B (en) * 2018-09-19 2024-04-19 发那科株式会社 Object monitoring system with distance measuring device
CN111198384A (en) * 2018-10-31 2020-05-26 发那科株式会社 Object monitoring system with distance measuring device
CN111198384B (en) * 2018-10-31 2024-04-05 发那科株式会社 Object monitoring system with distance measuring device

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