JP3451535B2 - Soil optical property measurement device - Google Patents
Soil optical property measurement deviceInfo
- Publication number
- JP3451535B2 JP3451535B2 JP25433197A JP25433197A JP3451535B2 JP 3451535 B2 JP3451535 B2 JP 3451535B2 JP 25433197 A JP25433197 A JP 25433197A JP 25433197 A JP25433197 A JP 25433197A JP 3451535 B2 JP3451535 B2 JP 3451535B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- soil
- photodetector
- soil surface
- measuring device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- Investigating Or Analysing Materials By Optical Means (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
- Cultivation Of Plants (AREA)
- Spectrometry And Color Measurement (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は土壌の光学特性測定
装置に関する。特に、土壌の光学特性を測定し、土壌の
成分を分析するための光学特性測定装置に関する。TECHNICAL FIELD The present invention relates to a soil optical property measuring apparatus. In particular, the present invention relates to an optical characteristic measuring device for measuring the optical characteristic of soil and analyzing the components of soil.
【０００２】[0002]
【従来の技術】農産物の収量を増加させるためには、土
壌中の有機成分や肥料等の不足分を補給し、耕作地全体
の土壌の均質化を図る必要がある。そのためには、土壌
の成分を分析する必要があり、特にリアルタイムに成分
分析することが望まれる。2. Description of the Related Art In order to increase the yield of agricultural products, it is necessary to supplement the shortage of organic components and fertilizers in the soil to homogenize the soil throughout the cultivated land. For that purpose, it is necessary to analyze the components of the soil, and it is particularly desirable to analyze the components in real time.
【０００３】そのための土壌成分分析装置としては、図
１に示すようなものが知られている（Soil Organic Mat
ter, CEC, and Moisture Sensing with a Portable NIR
Spectrophotometer; K. A. Sudduth, J. W. Hummel: T
ransactions of the ASAE, 1993 Vol.36, 1571-158
2）。この土壌成分分析装置１は、トラクタ後部の鋤２
の直後に取り付けられており、トラクタで土壌成分分析
装置１を牽引して圃場を移動し、鋤２で露出させられた
新しい土壌面３を土壌成分分析装置１で分析し、土壌中
の有機物量や水分等を測定するものである。As a soil component analyzer for that purpose, the one shown in FIG. 1 is known (Soil Organic Mat).
ter, CEC, and Moisture Sensing with a Portable NIR
Spectrophotometer; KA Sudduth, JW Hummel: T
ransactions of the ASAE, 1993 Vol.36, 1571-158
2). This soil component analyzer 1 is equipped with a plow 2 at the rear of the tractor.
It is attached immediately after, and the soil component analyzer 1 is pulled by a tractor to move in the field, and the new soil surface 3 exposed by the plow 2 is analyzed by the soil component analyzer 1 to determine the amount of organic matter in the soil. It measures the water content and the like.
【０００４】この土壌成分分析装置１においては、光源
４から放射された白色光は、集光レンズ５によりバンド
ル光ファイバ６の一方端面に集光される。このとき、集
光レンズ５で集光された白色光は、スリット板７及び波
長選択フィルタ８を通過してバンドル光ファイバ６の端
面に入射する。波長選択フィルタ８は、図２に示すよう
な円板状をしたフィルタディスク９の扇形開口１０に設
けられており、フィルタディスク９の円周方向に沿って
選択波長（透過波長）が連続的に変化するように配設さ
れている。フィルタディスク９は回転モータ１１によっ
て回転駆動される。スリット板７の開口１２はフィルタ
ディスク９の半径方向に沿って細長く位置しているの
で、フィルタディスク９が回転していると、スリット板
７及び波長選択フィルタ８を通過してバンドル光ファイ
バ６の端面に入射する単色の測定光の波長は連続的に変
化する。波長選択フィルタ８による選択波長は、４００
〜２５００ｎｍの範囲の紫外光から近赤外光を用いるこ
とが多い。回転モータ１１によるフィルタディスク９の
回転は、モータ制御部１３によって制御されており、モ
ータ制御信号はモータ制御部１３からデータ処理装置１
４へも送出されているので、データ処理装置１４ではバ
ンドル光ファイバ６の端面に入射されている測定光（単
色光）の波長を認識している。バンドル光ファイバ６の
他端は投受光箱１５へ導かれており、バンドル光ファイ
バ６の一方端面から入射した測定光は、バンドル光ファ
イバ６内部を伝搬して他方端面から出射し、投受光箱１
５の底面に設けられた石英窓１６を透過し、鋤２によっ
て露出させられた耕作地等の新しい土壌面３へ照射され
る。In the soil component analyzer 1, the white light emitted from the light source 4 is condensed by the condenser lens 5 on one end surface of the bundle optical fiber 6. At this time, the white light condensed by the condenser lens 5 passes through the slit plate 7 and the wavelength selection filter 8 and is incident on the end face of the bundle optical fiber 6. The wavelength selection filter 8 is provided in the fan-shaped opening 10 of the disk-shaped filter disk 9 as shown in FIG. 2, and the selected wavelength (transmission wavelength) is continuously arranged along the circumferential direction of the filter disk 9. It is arranged to change. The filter disk 9 is rotationally driven by a rotary motor 11. Since the opening 12 of the slit plate 7 is elongated along the radial direction of the filter disk 9, when the filter disk 9 is rotated, it passes through the slit plate 7 and the wavelength selection filter 8 and the bundle optical fiber 6 passes. The wavelength of the monochromatic measuring light incident on the end face continuously changes. The wavelength selected by the wavelength selection filter 8 is 400
Ultraviolet to near infrared light is often used in the range of up to 2500 nm. The rotation of the filter disk 9 by the rotary motor 11 is controlled by the motor control unit 13, and the motor control signal is sent from the motor control unit 13 to the data processing device 1.
The data processing device 14 recognizes the wavelength of the measurement light (monochromatic light) incident on the end face of the bundle optical fiber 6 because the light is also transmitted to the optical fiber 4. The other end of the bundle optical fiber 6 is guided to the light projecting / receiving box 15, and the measurement light incident from one end surface of the bundle optical fiber 6 propagates inside the bundle optical fiber 6 and exits from the other end surface of the bundle optical fiber 6. 1
The light passes through a quartz window 16 provided on the bottom surface of No. 5 and is irradiated to a new soil surface 3 such as cultivated land exposed by the plow 2.
【０００５】こうして土壌面３に照射された単色の測定
光は土壌面３で散乱反射され、散乱反射光は石英窓１６
を通って再び投受光箱１５内へ戻る。投受光箱１５内へ
戻った散乱反射光の一部は、投受光箱１５内部のバンド
ル光ファイバ６近傍に設けられた光検出器１７で受光さ
れる。光検出器１７は、受光した散乱反射光の強度に応
じた受光信号をデータ処理装置１４へ送信する。The monochromatic measuring light thus radiated on the soil surface 3 is scattered and reflected by the soil surface 3, and the scattered reflected light is reflected by the quartz window 16.
And returns to the inside of the light emitting / receiving box 15 again. A part of the scattered and reflected light returning to the inside of the light projecting / receiving box 15 is received by the photodetector 17 provided near the bundle optical fiber 6 inside the light projecting / receiving box 15. The photodetector 17 transmits a light reception signal according to the intensity of the received scattered reflection light to the data processing device 14.
【０００６】ついで、データ処理装置１４は、図３に示
すように、モータ制御部１３から受け取ったモータ制御
信号を測定光の波長データに変換し（Ｓ１）、この波長
データと光検出器１７における受光信号とから当該土壌
の散乱反射光の光スペクトルを作成し（Ｓ２）、この散
乱反射光の光スペクトル強度に関するデータを、予め作
成してある所定の回帰式に代入する（Ｓ３）ことによっ
て当該土壌の成分を分析し、分析結果を表示部（図示せ
ず）に表示する（Ｓ４）。なお、回帰式は、多変量解析
として知られる手続により作成する。Next, as shown in FIG. 3, the data processor 14 converts the motor control signal received from the motor controller 13 into wavelength data of the measuring light (S1), and the wavelength data and the photodetector 17 An optical spectrum of the scattered reflected light of the soil is created from the received light signal (S2), and data relating to the optical spectrum intensity of the scattered reflected light is substituted into a predetermined regression formula created in advance (S3). The components of the soil are analyzed, and the analysis result is displayed on the display unit (not shown) (S4). The regression equation is created by a procedure known as multivariate analysis.
【０００７】[0007]
【発明が解決しようとする課題】従来の土壌成分分析装
置は、上記のように鋤で露出させた新しい土壌面にバン
ドル光ファイバから連続的に変化する測定光（単色光）
を照射し、土壌面で散乱反射した光をバンドル光ファイ
バの近傍に配置した光検出器で受光し、その受光強度か
ら散乱反射光の光スペクトルを得ている。The conventional soil component analyzer is a measuring light (monochromatic light) that continuously changes from the bundle optical fiber to the new soil surface exposed by the plow as described above.
The light scattered by the soil surface is received by a photodetector arranged near the bundle optical fiber, and the light spectrum of the scattered reflected light is obtained from the intensity of the received light.
【０００８】しかしながら、土壌は一般に粒子の大きさ
や構造、土質が不均一で、さらには小さな石や異物など
が混入していることが多い。土壌にこのような不均一が
存在していると、土壌に測定光を照射しても、その散乱
反射光は全方位に均等に反射されず、特定の方向に強く
あるいは弱く、偏って反射されることになり、光照射の
方向や光検出器の位置によって光学特性が異なり、正確
に土壌成分を分析できない。However, the soil generally has non-uniform particle size, structure and soil quality, and often contains small stones and foreign substances. When such unevenness is present in the soil, even when the soil is irradiated with the measurement light, the scattered reflected light is not reflected uniformly in all directions, but is strongly or weakly reflected in a specific direction and is unevenly reflected. As a result, the optical characteristics differ depending on the direction of light irradiation and the position of the photodetector, and soil components cannot be accurately analyzed.
【０００９】また、土壌成分分析装置を圃場で移動させ
て連続的に土壌の光学特性を測定する場合には、土壌面
と光検出器の距離が土壌成分分析装置の移動によって変
動するので、土壌に照射される照射面積が変動し、また
土壌から光検出器に入射する散乱反射光の強度が変動す
るため、土壌の光学特性の測定精度が低下し、正確に土
壌成分を知ることができなかった。When the soil component analyzer is moved in the field to continuously measure the optical characteristics of the soil, the distance between the soil surface and the photodetector varies depending on the movement of the soil component analyzer. Since the irradiation area of the soil varies and the intensity of scattered reflected light that enters the photodetector from the soil varies, the accuracy of measuring the optical properties of the soil decreases and it is not possible to know the soil components accurately. It was
【００１０】従来の土壌成分分析装置では、土壌面と光
検出器の距離が短い（例えば、１５ｍｍ程度）ので、こ
のような原因による測定精度の低下やばらつきが著しか
った。土壌面と光検出器の距離の変動による測定精度の
低下などを低減するためには、土壌面と光検出器等との
距離を長くすればよいが、従来の土壌成分分析装置で
は、土壌面と光検出器との距離を長くすると、光検出器
に入射する散乱反射光の強度が急激に低減するので、か
えって測定精度が低下したり、測定不能になっていた。In the conventional soil component analyzer, the distance between the soil surface and the photodetector is short (for example, about 15 mm), so that the deterioration or variation in measurement accuracy due to such a cause is significant. The distance between the soil surface and the photodetector can be increased in order to reduce the decrease in measurement accuracy due to the variation in the distance between the soil surface and the photodetector. When the distance between the photodetector and the photodetector is increased, the intensity of scattered reflected light incident on the photodetector sharply decreases, so that the measurement accuracy deteriorates or the measurement becomes impossible.
【００１１】本発明は前述の従来例の欠点に鑑みてなさ
れたものであり、その目的とするところは、土壌の形状
や構造、土質等あるいは土壌面の凹凸のばらつき等によ
らず、土壌の光学的特性を精度よく測定することがで
き、また土壌面と光検出器との光学的距離を長くして測
定精度を向上させることができる土壌の光学特性測定装
置を提供することにある。The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and the object thereof is to obtain the soil regardless of the shape and structure of the soil, the soil quality and the like or the unevenness of the soil surface. An object of the present invention is to provide a soil optical characteristic measuring device capable of measuring optical characteristics with high accuracy and increasing the optical distance between the soil surface and the photodetector to improve the measurement accuracy.
【００１２】[0012]
【発明の開示】請求項１に記載の土壌の光学特性測定装
置は、土壌面に向けて、波長帯域の広い測定光を照射す
る光源と、土壌面で散乱反射された測定光を捕捉して閉
じ込める光捕捉部と、土壌面の広い面積で散乱反射され
た測定光を集光して、前記光捕捉部内へ導く集光手段
と、前記光捕捉部内の光を分光する手段と、前記分光手
段によって分光された光を受光する光検出器と、前記光
検出器の測定データに基づいて土壌の光学特性を分析す
る手段とを備えたことを特徴としている。DISCLOSURE OF THE INVENTION An optical characteristic measuring apparatus for soil according to claim 1 captures a light source for irradiating a measuring light having a wide wavelength band toward a soil surface and a measuring light scattered and reflected by the soil surface. A light trapping part for confining, a condensing means for condensing the measurement light scattered and reflected in a wide area of the soil surface and guiding it into the light trapping part, a means for spectrally splitting the light in the light trapping part, and the spectroscopic means. And a means for analyzing the optical characteristics of the soil based on the measurement data of the photodetector.
【００１３】この土壌の光学特性測定装置にあっては、
光源から土壌面に向けて測定光を照射し、土壌面の広い
面積で散乱反射された測定光を集光手段で光捕捉部内に
集めて捕捉する。光捕捉部内に閉じ込められた散乱反射
光は、光捕捉部内で何度か反射された後、分光手段に入
射する。分光手段で分光された光は光検出器で受光され
る。分析手段は、光検出器の測定データ（受光量）に基
づいて土壌の光学特性を分析する。In this soil optical characteristic measuring device,
Irradiate the measuring light from the light source toward the soil surface, and the soil surface is wide.
The measurement light scattered and reflected by the area is collected and captured in the light capturing section by the light collecting means. The scattered reflected light confined in the light capturing portion is reflected several times in the light capturing portion and then enters the spectroscopic means. The light split by the splitting means is received by the photodetector. The analysis means analyzes the optical characteristics of the soil based on the measurement data (light reception amount) of the photodetector.
【００１４】従って、本発明によれば、土壌面で散乱反
射された測定光を光検出器で直接受光するのでなく、土
壌面で散乱反射され大きな立体角で放射された広い範囲
の散乱反射光を光捕捉部内に捕捉することによって平均
化して光検出器で検出することができるので、土壌の形
状や構造、土質、粒子の大きさ等によらず土壌本来の光
学的特性を測定することができ、測定データの信頼性を
向上させることができる。Therefore, according to the present invention, the measurement light scattered and reflected on the soil surface is not directly received by the photodetector, but is scattered and reflected on the soil surface and emitted in a large solid angle over a wide range. It is possible to measure the original optical characteristics of the soil regardless of the shape and structure of the soil, soil quality, particle size, etc. It is possible to improve the reliability of measurement data.
【００１５】また、土壌面で散乱反射された測定光を集
光手段により集光させて光捕捉部内へ導いているので、
土壌面と光捕捉部との距離が長い場合でも、土壌面の広
い面積にわたって散乱反射した測定光を集めて光補捉部
内へ導くことができ、光検出器における受光強度を高く
することができる。さらに、土壌面には波長帯域の広い
光、例えば白色光を照射しているので、土壌面の照射強
度を大きくでき、一層土壌面と光検出器との距離を長く
できる。Further, since the measuring light scattered and reflected on the soil surface is condensed by the condensing means and guided into the light capturing portion,
Even when the distance between the soil surface and the light trap is long, the measurement light scattered and reflected over a wide area of the soil surface can be collected and guided into the light trap, and the light receiving intensity at the photodetector can be increased. . Further, since the soil surface is irradiated with light having a wide wavelength band, for example, white light, the irradiation intensity on the soil surface can be increased, and the distance between the soil surface and the photodetector can be further increased.
【００１６】従って、土壌面と光捕捉部ひいては光検出
器との距離を長くすることができるので、測定地域での
移動によって土壌面と光検出器との距離が変動しても土
壌の光学的特性に及ぼす影響が少なくなり、測定精度が
向上し、測定ばらつきが低減される。Therefore, since the distance between the soil surface and the light trapping portion, and thus the photodetector, can be increased, even if the distance between the soil surface and the photodetector varies due to movement in the measurement area, the optical properties of the soil can be changed. The influence on the characteristics is reduced, the measurement accuracy is improved, and the measurement variation is reduced.
【００１７】請求項２に記載の土壌の光学特性測定装置
は、土壌面に向けて、複数波長からなる測定光を照射す
る光源と、土壌面で散乱反射された測定光を捕捉して閉
じ込める光捕捉部と、土壌面の広い面積で散乱反射され
た測定光を集光して、前記光捕捉部内へ導く集光手段
と、前記光捕捉部内の光を異なる波長毎に分離する手段
と、前記分離手段によって分離された光を受光する光検
出器と、前記光検出器の測定データに基づいて土壌の光
学特性を分析する手段とを備えたことを特徴としてい
る。The soil optical characteristic measuring device according to a second aspect of the invention is a light source for irradiating a measurement light having a plurality of wavelengths toward a soil surface and a light for trapping and confining the measurement light scattered and reflected by the soil surface. A trapping unit, condensing the measurement light scattered and reflected in a wide area of the soil surface, a condensing unit for guiding the light into the light trapping unit, a unit for separating the light in the light trapping unit for each different wavelength, and It is characterized by comprising a photodetector for receiving the light separated by the separating means and a means for analyzing the optical characteristics of the soil based on the measurement data of the photodetector.
【００１８】この土壌の光学特性測定装置は、請求項１
の光学特性測定装置とは、光源が離散的な複数波長の測
定光を照射する点で異なっているが、このような光学特
性測定装置にあっても、請求項１の光学特性測定装置と
同様な作用効果を奏する。すなわち、土壌の形状や構
造、土質、粒子の大きさ等によらず土壌本来の光学的特
性を測定することができ、測定データの信頼性を向上さ
せることができる。また、土壌面と光検出器との距離を
長くできるので、測定地域での移動によって土壌面と光
検出器との距離が変動しても土壌の光学的特性に及ぼす
影響が少なくなり、測定精度が向上し、測定ばらつきが
低減される。The optical property measuring device for soil according to claim 1
Is different from the optical characteristic measuring apparatus of claim 1 in that the light source emits discrete measuring light of a plurality of wavelengths, and such an optical characteristic measuring apparatus is the same as the optical characteristic measuring apparatus of claim 1. It has various effects. That is, the original optical characteristics of the soil can be measured regardless of the shape and structure of the soil, the soil quality, the size of the particles, etc., and the reliability of the measurement data can be improved. In addition, since the distance between the soil surface and the photodetector can be increased, even if the distance between the soil surface and the photodetector changes due to movement in the measurement area, the influence on the optical characteristics of the soil will be reduced, and the measurement accuracy will be reduced. Is improved and measurement variations are reduced.
【００１９】上記光捕捉部としては、請求項３に記載の
ように、高反射率の内面を有する略球状の空洞を用いる
ことができる。このような光捕捉部にあっては、開口か
ら光捕捉部内に入った散乱反射光は土壌面における反射
方向によらず、光捕捉部の内面で反射を繰り返して分光
手段に入るので、光受光器では各方向へ反射された光の
強度を平均化したものを検出することができる。As the light-trapping portion, as described in claim 3, a substantially spherical cavity having an inner surface with high reflectance can be used. In such a light trap, the scattered reflected light entering the light trap through the opening is repeatedly reflected on the inner surface of the light trap and enters the spectroscopic means regardless of the reflection direction on the soil surface. The detector can detect the averaged intensity of the light reflected in each direction.
【００２０】請求項４に記載の実施態様は、請求項１又
は２に記載の土壌の光学特性測定装置において、前記集
光手段によって土壌面の像を前記光捕捉部の受光窓に結
像させることを特徴としている。 The embodiment described in claim 4 is the same as claim 1 or
In the soil optical property measuring device according to the item 2,
An image of the soil surface is formed on the light-receiving window of the light-trapping unit by light means.
The feature is to make it image.
【００２１】請求項５に記載の実施態様は、請求項１又
は２に記載の土壌の光学特性測定装置において、土壌面
との対向部分と土壌面の間を遮光部材で覆ったことを特
徴としている。The embodiment described in claim 5 is characterized in that, in the optical characteristic measuring device for soil according to claim 1 or 2, a space between the portion facing the soil surface and the soil surface is covered with a light shielding member. There is.
【００２２】この実施態様のように、土壌面との間を遮
光部材で覆うようにすれば、外乱光の影響を排除するこ
とができ、測定感度や信頼性をより向上させることがで
きる。By covering the soil surface with a light-shielding member as in this embodiment, the influence of ambient light can be eliminated, and the measurement sensitivity and reliability can be further improved.
【００２３】請求項６に記載の実施態様は、請求項１又
は２に記載の土壌の光学特性測定装置において、前記光
源から投光方向に参照板を配置したり、投光方向から外
れた位置へ取り除いたりできるようにしたことを特徴と
している。According to a sixth aspect of the present invention, in the soil optical characteristic measuring apparatus according to the first or second aspect, a reference plate is arranged in the light projecting direction from the light source or a position deviated from the light projecting direction. The feature is that it can be removed.
【００２４】この実施態様によれば、光源の投光方向に
参照板を配置し、参照板に測定光を照射して参照板の光
学特性をモニターすることによって、光学系の不安定性
（例えば、光検出器の感度変化や光源の光源強度の揺ら
ぎ等）による光学特性の変動を補正することができる。
なお、参照板を光源の投光方向から外れた位置へ移動さ
せることにより、土壌面を測定できる。According to this embodiment, the instability of the optical system (for example, by arranging the reference plate in the light emitting direction of the light source and irradiating the reference plate with the measuring light to monitor the optical characteristics of the reference plate). It is possible to correct variations in optical characteristics due to changes in the sensitivity of the photodetector, fluctuations in the light source intensity of the light source, and the like.
The soil surface can be measured by moving the reference plate to a position deviated from the light projecting direction of the light source.
【００２５】請求項７に記載の実施態様は、請求項１又
は２に記載の土壌の光学特性測定装置において、測定位
置を特定するための測定位置計測装置を備えたことを特
徴としている。A seventh aspect of the present invention is characterized in that the soil optical characteristic measuring device according to the first or second aspect further includes a measuring position measuring device for specifying a measuring position.
【００２６】この実施態様によれば、測定位置計測装置
により測定位置を特定することができるので、測定デー
タと測定位置とを関連付けることができる。従って、土
壌成分などの測定データを測定地域全体で総合的に分析
することができる。また、後日、測定データに基づいて
土壌改良を行なう場合にも、測定位置と関連付けられて
いるので、容易に作業を行なうことができる。According to this embodiment, since the measurement position can be specified by the measurement position measuring device, the measurement data and the measurement position can be associated with each other. Therefore, the measurement data such as soil components can be comprehensively analyzed in the entire measurement area. Further, even when the soil is improved at a later date based on the measurement data, the work can be easily performed because it is associated with the measurement position.
【００２７】特に、請求項８に記載の実施態様は、位置
情報と測定データとから、土壌の特性マップを自動作成
することができる。Particularly, in the embodiment described in claim 8, a soil characteristic map can be automatically created from the position information and the measurement data.
【００２８】[0028]
（第１の実施形態）図４は本発明の一実施形態による土
壌の光学特性測定装置２１の構成を示す概略図である。
この光学特性測定装置２１は、光源２２、集光レンズ２
３、光積分球２４、分光装置２５、光検出器２６および
データ処理装置２７から構成されている。光源２２は、
白色光を土壌面３へ照射するものであって、ハロゲンラ
ンプ等からなる。光源２２は、集光レンズ（単レンズ）
２３を保持する鏡筒２８の外周部に環状に配置されてお
り、光源２２の上面側及び外周側は反射板２９により覆
われている。なお、図示していないが、集光レンズ２３
の鏡筒２８と光積分球２４の間は、外乱光が入らないよ
う適宜手段により遮光されている。(First Embodiment) FIG. 4 is a schematic view showing the arrangement of a soil optical characteristic measuring apparatus 21 according to an embodiment of the present invention.
The optical characteristic measuring device 21 includes a light source 22 and a condenser lens 2.
3, an optical integrating sphere 24, a spectroscopic device 25, a photodetector 26, and a data processing device 27. The light source 22 is
It irradiates the soil surface 3 with white light and comprises a halogen lamp or the like. The light source 22 is a condenser lens (single lens)
It is arranged in an annular shape on the outer peripheral portion of a lens barrel 28 holding 23, and the upper surface side and the outer peripheral side of the light source 22 are covered with a reflection plate 29. Although not shown, the condenser lens 23
A space between the lens barrel 28 and the light integrating sphere 24 is appropriately shielded so that ambient light does not enter.
【００２９】光源２２から出射された白色光（測定光）
は土壌面３を照射する。この土壌面３は鋤２によって土
壌を掻き取って露出させた新しい土壌面であって、光源
２２及び集光レンズ２３とほぼ一定の距離にある。ここ
で、光源２２からの白色光を土壌面３に照射するように
しているので、土壌面３の照射強度を大きくできる。White light (measurement light) emitted from the light source 22
Irradiates the soil surface 3. The soil surface 3 is a new soil surface exposed by scraping off the soil with the plow 2, and is at a substantially constant distance from the light source 22 and the condenser lens 23. Here, since the white light from the light source 22 is applied to the soil surface 3, the irradiation intensity of the soil surface 3 can be increased.
【００３０】光積分球２４は、略球殻状をしていて下面
には受光窓３０が設けられている。光積分球２４の内部
には、光捕捉部となる空洞が設けられており、その内壁
面は反射率がほぼ１００％の光拡散面（または、鏡面）
となっている。この光積分球２４の一部には、内部の光
を分光装置２５へ導くための透孔３１が開口されてい
る。The light integrating sphere 24 has a substantially spherical shell shape, and a light receiving window 30 is provided on the lower surface thereof. Inside the light integrating sphere 24, a cavity serving as a light trapping portion is provided, and the inner wall surface thereof has a light diffusing surface (or a mirror surface) with a reflectance of almost 100%.
Has become. A through hole 31 for guiding the internal light to the spectroscopic device 25 is opened in a part of the light integrating sphere 24.
【００３１】ここで、集光レンズ２３及び光積分球２４
の位置関係は、鋤２によって露出させられた新しい土壌
面３の像を集光レンズ２３によって光積分球２４の受光
窓３０に結像させるようにしている。すなわち、集光レ
ンズ２３の焦点距離をｆ、土壌面３と集光レンズ２３の
距離をａ、集光レンズ２３と受光窓３０の距離をｂとす
れば、
（１／ａ）＋（１／ｂ）＝（１／ｆ）
の関係をほぼ満たすようにしている。Here, the condenser lens 23 and the light integrating sphere 24
As for the positional relationship of, the image of the new soil surface 3 exposed by the plow 2 is formed on the light receiving window 30 of the light integrating sphere 24 by the condenser lens 23. That is, if the focal length of the condenser lens 23 is f, the distance between the soil surface 3 and the condenser lens 23 is a, and the distance between the condenser lens 23 and the light receiving window 30 is b, then (1 / a) + (1 / b) = (1 / f) is almost satisfied.
【００３２】よって、土壌面３と光積分球２４との距離
（ａ＋ｂ）が長くても、ａ＞ｂの関係を満たすように土
壌面３と集光レンズ２３の間の距離を充分に取ってあれ
ば、図４からも分かるように、土壌面３の広い面積で散
乱反射された白色光が光積分球２４の受光窓３０に集め
られる。光積分球２４内に入った散乱反射光は、光積分
球２４の内部で吸収されることなく拡散反射を繰り返し
た後、透孔３１から分光装置２５へ導かれる。従って、
光積分球２４が土壌面３から大きな距離離れていても、
土壌面３の（受光窓３０の面積に比べて）広い面積で散
乱反射された白色光が分光装置２５、ひいては光検出器
２６へ導かれ、高い測定感度を得ることができる。Therefore, even if the distance (a + b) between the soil surface 3 and the light integrating sphere 24 is long, the distance between the soil surface 3 and the condenser lens 23 should be sufficiently large so as to satisfy the relationship of a> b. If so, as can be seen from FIG. 4, the white light scattered and reflected in a wide area of the soil surface 3 is collected in the light receiving window 30 of the light integrating sphere 24. The scattered reflected light that has entered the light integrating sphere 24 is repeatedly diffused and reflected without being absorbed inside the light integrating sphere 24, and then is guided to the spectroscopic device 25 from the through hole 31. Therefore,
Even if the light integrating sphere 24 is far away from the soil surface 3,
White light scattered and reflected in a large area of the soil surface 3 (compared to the area of the light receiving window 30) is guided to the spectroscopic device 25, and further to the photodetector 26, and high measurement sensitivity can be obtained.
【００３３】本発明の土壌の光学特性測定装置２１にあ
っては、こうして土壌面３と光積分球２４ひいては光検
出器２６との距離を長くできるので、圃場での移動によ
って土壌面３と光検出器２６との距離が変動しても土壌
の光学的特性に及ぼす影響が少なくなり、測定精度が向
上し、測定ばらつきも低減する。In the soil optical characteristic measuring device 21 of the present invention, since the distance between the soil surface 3 and the light integrating sphere 24 and thus the photodetector 26 can be lengthened in this manner, the soil surface 3 and the light can be moved by moving in the field. Even if the distance from the detector 26 varies, the influence on the optical characteristics of the soil is reduced, the measurement accuracy is improved, and the measurement variation is reduced.
【００３４】また、集光レンズ２３によって土壌面３の
像を光積分球２４の受光窓３０に結像させているから、
土壌面３で不規則かつ不均一に様々な方向へ反射された
散乱反射光も受光窓３０から光積分球２４内へ集めら
れ、光積分球２４内部で平均化され、各方向で均一化さ
れた散乱反射光が透孔３１から分光装置２５へ送り出さ
れる。Since the image of the soil surface 3 is formed on the light receiving window 30 of the light integrating sphere 24 by the condenser lens 23,
Scattered reflected light reflected in various directions irregularly and non-uniformly on the soil surface 3 is also collected from the light receiving window 30 into the light integrating sphere 24, averaged inside the light integrating sphere 24, and made uniform in each direction. The scattered reflected light is sent out from the through hole 31 to the spectroscopic device 25.
【００３５】土壌の性質（成分）が同じでも、土壌の表
面の傾きや凹凸、土壌粒子の大きさ等が異なると、その
分布により土壌面３から散乱反射される光の強度は検出
する方向によりばらつきが生じる。しかし、本発明の光
学特性測定装置２１のように、土壌面３で散乱反射され
た測定光を分光装置２５もしくは光検出器２６で直接受
光するのでなく、土壌面３で散乱反射され大きな立体角
で放射された広い範囲の散乱反射光を光積分球２４内に
捕捉することによって平均化して分光装置２５もしくは
光検出器２６で受光すれば、土壌の形状や構造、土質、
粒子の大きさ等によらず土壌本来の光学的特性を測定す
ることができ、測定データの信頼性を向上させることが
できる。Even if the properties (components) of the soil are the same, if the inclination or unevenness of the soil surface, the size of the soil particles, etc. are different, the intensity of the light scattered and reflected from the soil surface 3 due to the distribution will depend on the direction of detection. There are variations. However, unlike the optical characteristic measuring device 21 of the present invention, the measuring light scattered and reflected by the soil surface 3 is not directly received by the spectroscopic device 25 or the photodetector 26, but is scattered and reflected by the soil surface 3 and has a large solid angle. If the scattered reflection light of a wide range emitted by the above is averaged by being captured in the light integrating sphere 24 and received by the spectroscopic device 25 or the photodetector 26, the shape and structure of the soil, soil quality,
The original optical characteristics of the soil can be measured regardless of the size of the particles, etc., and the reliability of the measurement data can be improved.
【００３６】分光装置２５は、光積分球２４の透孔３１
から導かれた散乱反射光のうち特定波長の光を選択的に
取り出し、その選択波長を所定の最短波長から最長波長
まで一定速度でスキャニングするものである。このよう
な分光装置２５としては、例えば従来例（図２）で述べ
たような、波長選択フィルタ（干渉フィルタ）８を備え
たフィルタディスク９とスリット板７からなるものを用
いることができる。The spectroscopic device 25 includes a through hole 31 of the light integrating sphere 24.
The light of a specific wavelength is selectively taken out of the scattered reflected light guided from, and the selected wavelength is scanned at a constant speed from a predetermined shortest wavelength to a longest wavelength. As such a spectroscopic device 25, for example, a device including a filter disk 9 provided with a wavelength selection filter (interference filter) 8 and a slit plate 7 as described in the conventional example (FIG. 2) can be used.
【００３７】あるいは、図５に示すように、白色光を色
分散させる回折格子３２とスリット板３３によって分光
装置２５を構成し、回折格子３２又はスリット板３３を
移動させることによって分光装置２５から出射される測
定光の波長を連続的に変化させるようにしたものでもよ
い。Alternatively, as shown in FIG. 5, a spectroscopic device 25 is constituted by a diffraction grating 32 and a slit plate 33 for color-dispersing white light, and the spectroscopic device 25 is emitted by moving the diffraction grating 32 or the slit plate 33. The wavelength of the measuring light used may be continuously changed.
【００３８】光検出器２６としては、ＩｎＧａＡｓ、Ｐ
ｂＳ、ＰｂＳｅなどの半導体受光素子やシリコンフォト
ダイオードなどを用いることができる。As the photodetector 26, InGaAs, P
A semiconductor light receiving element such as bS or PbSe, a silicon photodiode, or the like can be used.
【００３９】こうして光検出器２６で分光された散乱反
射光が受光されると、光検出器２６からデータ処理装置
２７へ受光信号が送られる。一方、データ処理装置２７
は、光検出器２６を経由して分光装置２５から測定光の
波長を示す信号も受信している。測定光が土壌面３で反
射されるとき、土壌の成分によって特定波長の光の吸収
が起きるから、土壌の成分に応じて特有の光スペクトル
（吸収スペクトル）を示す。分光装置２５によって分光
により取り出す波長を連続的に変化させながら、光検出
器２６で受光している光強度を検出すれば、散乱反射光
の光スペクトルが得られるから、これをデータ処理装置
２７で解析することにより当該土壌の成分を分析するこ
とができる。When the scattered reflected light dispersed by the photodetector 26 is received in this manner, a photodetection signal is sent from the photodetector 26 to the data processing device 27. On the other hand, the data processing device 27
Also receives a signal indicating the wavelength of the measurement light from the spectroscopic device 25 via the photodetector 26. When the measurement light is reflected by the soil surface 3, absorption of light of a specific wavelength occurs due to the soil component, and thus a specific light spectrum (absorption spectrum) is shown according to the soil component. If the intensity of the light received by the photodetector 26 is detected while continuously changing the wavelength extracted by the spectroscopic device 25, the optical spectrum of the scattered reflected light can be obtained. By analyzing, the component of the said soil can be analyzed.
【００４０】（第２の実施形態）図６は本発明の別な実
施形態による土壌の光学特性測定装置３４の一部破断し
た断面図である。この実施形態にあっては、集光レンズ
２３に外乱光が入って測定精度が低下するのを防止する
ため、反射板２９から延出するようにして土壌面３の近
くまで遮光カバー３５を垂下している。また、光源２２
及び集光レンズ２３の下方には参照板３６が設けられて
おり、参照板３６は一端を遮光カバー３５に枢着し、参
照板３６を立てて遮光カバー３５の下面を開き、参照板
３６を倒して遮光カバー３５の下面を閉じるようにして
いる。参照板３６としては、アルミナなどのセラミック
板などを用いることができ、その両面は反射率がほぼ１
００％となっている。(Second Embodiment) FIG. 6 is a partially broken sectional view of a soil optical characteristic measuring apparatus 34 according to another embodiment of the present invention. In this embodiment, in order to prevent the disturbance light from entering the condenser lens 23 and lowering the measurement accuracy, the light shielding cover 35 is hung down near the soil surface 3 so as to extend from the reflecting plate 29. is doing. In addition, the light source 22
A reference plate 36 is provided below the condenser lens 23. One end of the reference plate 36 is pivotally attached to the light shielding cover 35, and the reference plate 36 is erected to open the lower surface of the light shielding cover 35 to open the reference plate 36. The lower surface of the light shielding cover 35 is closed to close it. As the reference plate 36, a ceramic plate such as alumina can be used, and both surfaces thereof have a reflectance of about 1
It is 00%.
【００４１】この実施形態によれば、参照板３６を倒し
て遮光カバー３５の下面を閉じ、参照板３６に白色光を
照射して参照板３６の光スペクトルをモニターすること
によって、光学系の不安定性（例えば、光検出器２６の
感度変化や光源強度の揺らぎ等）による光学特性の変動
を検出し、測定データの補正に使用することができる。
なお、参照板３６を立てて遮光カバー３５の下面を開く
ことにより、土壌面３を測定できる。According to this embodiment, the reference plate 36 is tilted to close the lower surface of the light-shielding cover 35, and the reference plate 36 is irradiated with white light to monitor the optical spectrum of the reference plate 36. It is possible to detect fluctuations in optical characteristics due to qualitative characteristics (for example, changes in sensitivity of the photodetector 26 and fluctuations in light source intensity), and use the corrections for measurement data.
The soil surface 3 can be measured by erecting the reference plate 36 and opening the lower surface of the light shielding cover 35.
【００４２】また、遮光カバー３５の、立てた参照板３
６と対向する箇所には、高圧エア噴射ノズル３７を設け
てあり、参照板３６が開かれたとき、高圧エア噴射ノズ
ル３７から高圧空気を参照板３６に吹き付けることによ
り参照板３６に付着した土や泥などを清掃除去できるよ
うにしている。なお、清掃する面は、白色光を照射する
参照板３６の上面側である。The standing reference plate 3 of the light-shielding cover 35
6, a high-pressure air injection nozzle 37 is provided, and when the reference plate 36 is opened, high-pressure air is blown from the high-pressure air injection nozzle 37 to the reference plate 36 so that the soil attached to the reference plate 36 is blown. It makes it possible to clean and remove dirt and mud. The surface to be cleaned is the upper surface side of the reference plate 36 that emits white light.
【００４３】この実施形態では、分光装置２５としては
反射型回折格子３８を用いており、光検出器２６として
はダイオードアレイ３９を用いている。このような構成
によれば、ダイオードアレイ３９の各ダイオード素子で
各波長を受光できるので、分光装置の波長をスキャンす
るための構造が不要となり、所定の光スペクトルを同時
に測定でき、光の利用効率が良好となる。In this embodiment, a reflection type diffraction grating 38 is used as the spectroscopic device 25, and a diode array 39 is used as the photodetector 26. According to such a configuration, since each wavelength can be received by each diode element of the diode array 39, a structure for scanning the wavelength of the spectroscopic device is not required, and a predetermined light spectrum can be measured at the same time, and the light utilization efficiency is improved. Will be good.
【００４４】（第３の実施形態）図７は本発明のさらに
別な実施形態による土壌の光学特性測定装置４０の構成
を示す概略図である。この光学特性測定装置４０にあっ
ては、集光手段として、凸面鏡４１と孔あき凹面鏡４２
からなる屈折反射鏡４３を用いている。このような構成
によれば、土壌面３から光積分球２４までの実際の距離
に比べて土壌面３から光積分球２４までの光学的距離を
長くすることができ、光学特性測定装置４０をコンパク
ト化できる。(Third Embodiment) FIG. 7 is a schematic view showing the arrangement of a soil optical characteristic measuring apparatus 40 according to still another embodiment of the present invention. In this optical characteristic measuring device 40, a convex mirror 41 and a perforated concave mirror 42 are used as a light collecting means.
The refracting / reflecting mirror 43 is used. With such a configuration, the optical distance from the soil surface 3 to the light integrating sphere 24 can be made longer than the actual distance from the soil surface 3 to the light integrating sphere 24. Can be made compact.
【００４５】また、光積分球２４と分光装置２５とを直
結することなく、光ファイバ４４（もしくは光ファイバ
束）を用いて光学的に結合しているので、分光装置２５
等の配置の自由度が増し、光学特性測定装置４０をコン
パクト化できる。Further, since the light integrating sphere 24 and the spectroscopic device 25 are not directly connected but are optically coupled by using the optical fiber 44 (or the optical fiber bundle), the spectroscopic device 25
The degree of freedom of arrangement of the optical characteristics measuring device 40 increases, and the optical characteristic measuring device 40 can be made compact.
【００４６】（第４の実施形態）図８は本発明のさらに
別な実施形態による土壌の光学特性測定装置４５の構成
を示す概略図である。この光学特性測定装置４５にあっ
ては、集光レンズ２３としてフレネルレンズ（回折レン
ズ）を用いている。また、光積分球２４に代えテーパ形
状の光導波路４６を用いており、端面の寸法の大きな側
（光入射側端面）を集光レンズ２３側に向け、端面の寸
法の小さな側（光出射側端面）に分光装置２５を配置し
ている。(Fourth Embodiment) FIG. 8 is a schematic view showing the arrangement of a soil optical characteristic measuring apparatus 45 according to still another embodiment of the present invention. In the optical characteristic measuring device 45, a Fresnel lens (diffraction lens) is used as the condenser lens 23. Further, instead of the light integrating sphere 24, a tapered optical waveguide 46 is used, and the side with a large end face size (light incident side end face) faces the condenser lens 23 side, and the side with a small end face size (light emitting side). The spectroscopic device 25 is disposed on the end face).
【００４７】図８では、円錐台状をした筒体の内周面が
鏡面となった光導波路４６を示しているが、屈折率の大
きな透明樹脂によって円錐台状に形成した光導波路４６
を用いてもよい。Although FIG. 8 shows the optical waveguide 46 in which the inner peripheral surface of the cylindrical body having a truncated cone shape is a mirror surface, the optical waveguide 46 formed with a transparent resin having a large refractive index into a truncated cone shape.
May be used.
【００４８】この実施形態にあっても、集光レンズ２３
によって土壌面３の像が光導波路４６の入射側端面に結
像されるようにしてあり、広い面積の土壌面３で散乱反
射した白色光が光導波路４６に集められ、また各散乱方
向の反射光も光導波路４６に集められ、光導波路４６に
入った散乱反射光は光導波路４６内を反射しながら分光
装置２５に入射する。Also in this embodiment, the condenser lens 23
The image of the soil surface 3 is formed on the incident side end surface of the optical waveguide 46 by the above, white light scattered and reflected by the soil surface 3 having a large area is collected in the optical waveguide 46, and reflection in each scattering direction is also performed. Light is also collected in the optical waveguide 46, and the scattered and reflected light entering the optical waveguide 46 enters the spectroscopic device 25 while being reflected in the optical waveguide 46.
【００４９】従って、土壌面３の凹凸などによらず、平
均化された散乱反射光を分光器へ導くことができ、測定
精度を安定化できる。Therefore, the averaged scattered reflected light can be guided to the spectroscope irrespective of the unevenness of the soil surface 3 and the measurement accuracy can be stabilized.
【００５０】（第５の実施形態）図９（ａ）は本発明の
さらに別な実施形態による土壌の光学特性測定装置の光
源２２を示す概略図、図９（ｂ）は分光装置（波長分離
装置）２５及び光検出器２６の構成を示す図である。こ
れは光源光として白色光を用いない実施形態である。図
９（ａ）に示すように、異なる発光波長を有する複数個
例えば３個の発光ダイオード（ＬＥＤ）や半導体レーザ
ー素子（ＬＤ）等の発光素子４７ａ，４７ｂ，４７ｃを
１組みにして鏡筒２８の周囲に配置して光源２２を構成
している。従って、この実施形態では、光源２２から
は、３つの波長λ１，λ２，λ３の光が土壌面３に照射
される。(Fifth Embodiment) FIG. 9A is a schematic view showing a light source 22 of a soil optical characteristic measuring apparatus according to still another embodiment of the present invention, and FIG. 9B is a spectroscopic apparatus (wavelength separation). It is a figure which shows the structure of the apparatus 25 and the photodetector 26. This is an embodiment in which white light is not used as the light source light. As shown in FIG. 9A, a plurality of, for example, three light emitting diodes (LED) or semiconductor laser elements (LD) having different emission wavelengths, such as light emitting elements 47a, 47b, and 47c, are combined into one lens barrel 28. The light source 22 is formed by arranging the light source 22 around. Therefore, in this embodiment, the light source 22 irradiates the soil surface 3 with light having three wavelengths λ1, λ2, and λ3.
【００５１】一方、分光装置２５は、図９（ｂ）に示す
ように、光積分球２４から入射した散乱反射光をコリメ
ートするコリメート鏡４８と、波長λ１の光のみを透過
させるダイクロイックミラー４９、波長λ３の光のみを
透過させるダイクロイックミラー５０、波長λ１の光の
みを透過させるバンドパスフィルタ５１、波長λ２の光
のみを透過させるバンドパスフィルタ５２、波長λ３の
光のみを透過させるバンドパスフィルタ５３からなって
おり、波長λ１の光を受光するための光検出器２６ａは
バンドパスフィルタ５１の透過側に配置され、波長λ２
の光を受光するための光検出器２６ｂはバンドパスフィ
ルタ５２の透過側に配置され、波長λ３の光を受光する
ための光検出器２６ｃはバンドパスフィルタ５３の透過
側に配置されている。On the other hand, the spectroscopic device 25, as shown in FIG. 9B, has a collimating mirror 48 for collimating the scattered reflection light incident from the light integrating sphere 24, a dichroic mirror 49 for transmitting only the light of wavelength λ1, A dichroic mirror 50 that transmits only light of wavelength λ3, a bandpass filter 51 that transmits only light of wavelength λ1, a bandpass filter 52 that transmits only light of wavelength λ2, and a bandpass filter 53 that transmits only light of wavelength λ3. The photodetector 26a for receiving the light of wavelength λ1 is arranged on the transmission side of the bandpass filter 51 and has the wavelength λ2.
The photodetector 26b for receiving the light of 1 is arranged on the transmission side of the bandpass filter 52, and the photodetector 26c for receiving the light of wavelength λ3 is arranged on the transmission side of the bandpass filter 53.
【００５２】（第６の実施形態）図１０は本発明のさら
に別な実施形態による土壌の光学特性測定装置５４の受
光側の構成を示す概略図である。この実施形態は、高精
度の測定を目的とするものであって、分光装置２５とし
ては、音響光学波長チューニング素子（Acoust-Optic T
unable Filter； 以下、ＡＯＴＦという）５５を用い
ている。(Sixth Embodiment) FIG. 10 is a schematic view showing the structure of the light receiving side of a soil optical characteristic measuring apparatus 54 according to still another embodiment of the present invention. This embodiment is intended for highly accurate measurement, and the spectroscopic device 25 includes an acousto-optic wavelength tuning element (Acoust-Optic T).
unable Filter; hereinafter referred to as AOTF) 55 is used.
【００５３】ＡＯＴＦ５５とは、白色光から単色光を分
離し、電気的に波長をスキャンするバンドパスフィルタ
であって、可動部分を持たない。ＡＯＴＦ５５は、音響
光学結晶［例えば、二酸化テルル（ＴｅＯ2）結晶の音
響波と光の進行方向が交差するもの］５６と音響波ドラ
イバー５７からなり、図１１に示すように、結晶５６の
対向する辺にトランスジューサ（Acoustic Transduce
r）５８とアブソーバ（Acoustic Absorber）５９が貼り
付けられており、音響波ドライバー５７からトランスジ
ューサ５８にＲＦ周波数の電気信号が印加されると、ト
ランスジューサ５８からアブソーバ５９へと結晶５６中
を音響波が通過し、音響波が通過するとき、結晶５６中
に生じる歪がグレーティングのような働きをする。この
ＡＯＴＦ５５に白色光が照射されていると、単色光だけ
が透過し、しかも、この透過波長はＲＦ周波数によって
制御することができる。この透過波長の半値幅は、波長
にもよるが１ｎｍのオーダーまで狭くすることができ、
透過率も高く最高９８％まで可能である。ただし、透過
光は０次回折光と±１次回折光とに分離するので、図１
１に示すように、０次回折光と−１次回折光（又は、＋
１次回折光）は光検出器２６に達しないよう遮蔽板６０
によりカットする。The AOTF 55 is a bandpass filter that separates monochromatic light from white light and electrically scans the wavelength, and has no movable part. The AOTF 55 includes an acousto-optic crystal [for example, one in which an acoustic wave of tellurium dioxide (TeO 2 ) crystal and a traveling direction of light intersect] 56 and an acoustic wave driver 57, and the crystal 56 faces each other as shown in FIG. 11. Acoustic Transduce
r) 58 and an absorber (Acoustic Absorber) 59 are attached, and when an electric signal of RF frequency is applied to the transducer 58 from the acoustic wave driver 57, an acoustic wave is generated in the crystal 56 from the transducer 58 to the absorber 59. When the acoustic wave passes, the strain generated in the crystal 56 acts like a grating. When the AOTF 55 is irradiated with white light, only monochromatic light is transmitted, and the transmitted wavelength can be controlled by the RF frequency. The full width at half maximum of this transmission wavelength can be narrowed to the order of 1 nm depending on the wavelength,
It has a high transmittance and can reach a maximum of 98%. However, since the transmitted light is separated into 0th-order diffracted light and ± 1st-order diffracted light,
As shown in 1, the 0th-order diffracted light and the -1st-order diffracted light (or +
The shield plate 60 prevents the first-order diffracted light from reaching the photodetector 26.
To cut.
【００５４】こうしてＡＯＴＦ５５からなる分光装置２
５を透過した単色光が光検出器２６に照射され、照射波
長は音響波ドライバー５７によって最短波長から最長波
長まで（例えば、４００ｎｍ〜２５００ｎｍ）スキャン
される。分光装置２５としてＡＯＴＦ５５を用いれば、
可動部分がなく、電気的に波長を制御できるから、波長
スキャン速度を高速化することができる。また、光検出
器２６には、ＩｎＧａＡｓ素子のような応答性のよい受
光素子を用いている。Thus, the spectroscopic device 2 including the AOTF 55
The monochromatic light having passed through 5 is irradiated onto the photodetector 26, and the irradiation wavelength is scanned by the acoustic wave driver 57 from the shortest wavelength to the longest wavelength (for example, 400 nm to 2500 nm). If AOTF55 is used as the spectroscopic device 25,
Since there is no movable part and the wavelength can be electrically controlled, the wavelength scanning speed can be increased. Further, the photodetector 26 uses a light receiving element having a good response such as an InGaAs element.
【００５５】一方、データ処理装置２７は、音響波ドラ
イバー５７からの信号によって照射波長を検知するとと
もに、光検出器２６から受光信号を受信している。デー
タ処理装置２７が、受光信号から光スペクトルを求める
方式としては、フーリエ変換型分光法を用いるのが好ま
しく、特に、インタフェログラム（interferogram）を
用いる方法が望ましい。ここで、インタフェログラムと
は、光線束干渉計の光路差を変えるとき、光路差ｘの関
数として測定記録した干渉光強度の変化Ｆ（ｘ）のこと
をいい、インタフェログラムＦ（ｘ）をフーリエ逆変換
することにより光スペクトルが求められる。これらのイ
ンタフェログラムやフーリエ変換型分光法などは、光ス
ペクトルを求めるための常法であるから、詳しい説明は
省略する。On the other hand, the data processing device 27 detects the irradiation wavelength by the signal from the acoustic wave driver 57 and receives the light reception signal from the photodetector 26. As a method for the data processing device 27 to obtain an optical spectrum from a received light signal, it is preferable to use Fourier transform type spectroscopy, and particularly to use an interferogram. Here, the interferogram means the change F (x) of the interference light intensity measured and recorded as a function of the optical path difference x when changing the optical path difference of the light beam interferometer, and the interferogram F (x) is a Fourier transform. The optical spectrum is obtained by inverse conversion. Since these interferograms and Fourier transform type spectroscopy are conventional methods for obtaining an optical spectrum, detailed description thereof will be omitted.
【００５６】また、この光学特性測定装置５４は、光源
２２の時間的変動を補正するための参照板３６を備えて
おり、つぎのような順序で光吸収スペクトルを求める。
まず、参照板３６を降ろして遮光カバー３５の下面を閉
じ、その状態で測定光の照射波長をスキャンして参照板
３６の拡散反射強度スペクトルＲ（λ）を測定する。つ
いで、参照板３６を上げて遮光カバー３５の下面を開
き、再度測定光の照射波長をスキャンして土壌の拡散反
射強度スペクトルＳ（λ）を測定する。そして、
吸収強度 Ａbs（λ）＝log［Ｒ（λ）／Ｓ（λ）］
から土壌の光吸収スペクトルを求める。Further, the optical characteristic measuring device 54 is provided with a reference plate 36 for correcting the temporal fluctuation of the light source 22, and obtains the light absorption spectrum in the following order.
First, the reference plate 36 is lowered, the lower surface of the light shielding cover 35 is closed, and in this state, the irradiation wavelength of the measurement light is scanned to measure the diffuse reflection intensity spectrum R (λ) of the reference plate 36. Then, the reference plate 36 is raised to open the lower surface of the light shielding cover 35, and the irradiation wavelength of the measurement light is scanned again to measure the diffuse reflection intensity spectrum S (λ) of the soil. Then, the light absorption spectrum of the soil is obtained from the absorption intensity Abs (λ) = log [R (λ) / S (λ)].
【００５７】この実施形態の光学特性測定装置５４で
は、分光装置２５として、電気的に高速高精度の波長
スキャンが可能なＡＯＴＦ５５を用いること、参照板
３６を用いて光源２２の揺らぎ等を補正すること、イ
ンタフェログラムにより光スペクトルを求めること、な
どによって高精度の土壌成分分析を可能にしている。In the optical characteristic measuring apparatus 54 of this embodiment, an AOTF 55 capable of electrically performing high-speed and high-precision wavelength scanning is used as the spectroscopic apparatus 25, and a reference plate 36 is used to correct fluctuations of the light source 22. It is possible to analyze soil components with high accuracy by, for example, obtaining an optical spectrum using an interferogram.
【００５８】（第７の実施形態）図１２は本発明のさら
に別な実施形態による土壌の光学特性測定装置６１の構
成を示す概略図である。この光学特性測定装置６１は、
測定位置検出装置６２を備えている。測定位置検出装置
６２としては、人工衛生を利用した測位システム（ＧＰ
Ｓ； Grobal Positioning System）、ジャイロセンサ等
を用いて移動方向や移動量を監視することによって位置
を検出する方式のものなどを用いることができる。測定
位置検出装置６２によって検出された位置情報はマップ
作成部へ送られる。マップ作成部６３では、データ処理
装置２７から得た土壌成分の情報と測定位置検出装置６
２から得た測定位置情報を関連付けて蓄積し、測定地域
全体における土壌成分マップを自動作成する。作成され
た土壌マップは、記録媒体に保存され、あるいはディス
プレイに表示され、あるいはプリンタ等から出力され
る。(Seventh Embodiment) FIG. 12 is a schematic view showing the arrangement of a soil optical characteristic measuring apparatus 61 according to still another embodiment of the present invention. This optical characteristic measuring device 61 is
A measurement position detection device 62 is provided. As the measurement position detection device 62, a positioning system using artificial hygiene (GP
S; Grobal Positioning System), a method of detecting a position by monitoring a moving direction or a moving amount using a gyro sensor or the like can be used. The position information detected by the measurement position detecting device 62 is sent to the map creating section. In the map creation unit 63, the soil component information obtained from the data processing device 27 and the measurement position detection device 6
The measurement position information obtained from 2 is associated and accumulated, and a soil component map for the entire measurement area is automatically created. The created soil map is stored in a recording medium, displayed on a display, or output from a printer or the like.
【図１】従来の土壌成分分析装置の構成を示す概略図で
ある。FIG. 1 is a schematic diagram showing a configuration of a conventional soil component analyzer.
【図２】同上のフィルタディスクを示す平面図である。FIG. 2 is a plan view showing the above filter disk.
【図３】データ処理装置における処理手順を示すフロー
図である。FIG. 3 is a flowchart showing a processing procedure in the data processing device.
【図４】本発明の一実施形態による土壌の光学特性測定
装置の構成を示す概略図である。FIG. 4 is a schematic diagram showing a configuration of an optical characteristic measuring apparatus for soil according to an embodiment of the present invention.
【図５】同上の光学特性測定装置に用いられている分光
装置の原理図である。FIG. 5 is a principle diagram of a spectroscopic device used in the optical characteristic measuring device of the above.
【図６】本発明の別な実施形態による土壌の光学特性測
定装置を示す一部破断した概略断面図である。FIG. 6 is a partially cutaway schematic sectional view showing a soil optical characteristic measuring apparatus according to another embodiment of the present invention.
【図７】本発明のさらに別な実施形態による土壌の光学
特性測定装置を示す一部破断した概略断面図である。FIG. 7 is a partially cutaway schematic sectional view showing a soil optical characteristic measuring apparatus according to still another embodiment of the present invention.
【図８】本発明のさらに別な実施形態による土壌の光学
特性測定装置を示す一部破断した概略断面図である。FIG. 8 is a partially cutaway schematic cross-sectional view showing a soil optical characteristic measuring apparatus according to still another embodiment of the present invention.
【図９】本発明のさらに別な実施形態による土壌の光学
特性測定装置を説明する図であって、（ａ）は光源部分
を示し、（ｂ）は分光装置及び光検出器を示す。9A and 9B are views for explaining an optical characteristic measuring apparatus for soil according to still another embodiment of the present invention, in which FIG. 9A shows a light source part, and FIG. 9B shows a spectroscopic device and a photodetector.
【図１０】本発明のさらに別な実施形態による土壌の光
学特性測定装置を示す概略断面図である。FIG. 10 is a schematic cross-sectional view showing a soil optical characteristic measuring apparatus according to still another embodiment of the present invention.
【図１１】音響光学波長チューニング素子の概略を示す
説明図である。FIG. 11 is an explanatory diagram showing an outline of an acousto-optic wavelength tuning element.
【図１２】本発明のさらに別な実施形態による土壌の光
学特性測定装置を示す概略断面図である。FIG. 12 is a schematic cross-sectional view showing a soil optical characteristic measuring apparatus according to still another embodiment of the present invention.
３ 土壌面 ２２ 光源 ２４ 光積分球 ２５ 分光装置 ２６ 光検出器 ２７ データ処理装置 ３５ 遮光カバー ３６ 参照板 ４７ａ，４７ｂ，４７ｃ 発光素子 ６２ 測定位置検出装置 ６３ マップ作成部 3 soil surface 22 Light source 24 Light integrating sphere 25 Spectroscopic device 26 Photodetector 27 Data processing device 35 light shield cover 36 Reference plate 47a, 47b, 47c Light emitting element 62 Measuring position detector 63 Map creation department
フロントページの続き (56)参考文献 特開 平８−29258（ＪＰ，Ａ) 特開 平６−102090（ＪＰ，Ａ) 特開 平８−37807（ＪＰ，Ａ) 特開 平７−120323（ＪＰ，Ａ) 国際公開96／027713（ＷＯ，Ａ１) Ｔｒａｎｓａｃｔｉｏｎｓ ｏｆ ｔ ｈｅ ＡＳＡＥ，1993年，ｖｏｌ．36, ｐ．1571−1582 (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 21/00 - 21/61 G01J 3/00 - 3/52 ＷＰＩ／Ｌ ＪＩＣＳＴファイル（ＪＯＩＳ) ＩＥＥＥ Ｘｐｌｏｒｅ Ｗｅｂ ｏｆ ＳｃｉｅｎｃｅContinuation of the front page (56) Reference JP-A-8-29258 (JP, A) JP-A-6-102090 (JP, A) JP-A-8-37807 (JP, A) JP-A-7-120323 (JP , A) International Publication 96/027713 (WO, A1) Transactions of the ASAE, 1993, vol. 36, p. 1571-1582 (58) Fields surveyed (Int.Cl. 7 , DB name) G01N 21/00-21/61 G01J 3/00-3/52 WPI / L JISST file (JOIS) IEEE Xplore Web of Science
Claims (8)
を照射する光源と、 土壌面で散乱反射された測定光を捕捉して閉じ込める光
捕捉部と、 土壌面の広い面積で散乱反射された測定光を集光して、
前記光捕捉部内へ導く集光手段と、 前記光捕捉部内の光を分光する手段と、 前記分光手段によって分光された光を受光する光検出器
と、 前記光検出器の測定データに基づいて土壌の光学特性を
分析する手段と、 を備えた土壌の光学特性測定装置。1. A light source for irradiating a measurement light having a wide wavelength band toward the soil surface, a light trap for trapping and confining the measurement light scattered and reflected by the soil surface, and a scattered reflection over a wide area of the soil surface. Collect the measured light,
Condensing means for guiding the light into the light capturing portion, means for dispersing the light within the light capturing portion, a photodetector for receiving the light dispersed by the spectral means, and soil based on the measurement data of the photodetector. An optical characteristic measuring device for soil, comprising means for analyzing the optical characteristics of the soil.
光を照射する光源と、 土壌面で散乱反射された測定光を捕捉して閉じ込める光
捕捉部と、 土壌面の広い面積で散乱反射された測定光を集光して、
前記光捕捉部内へ導く集光手段と、 前記光捕捉部内の光を異なる波長毎に分離する手段と、 前記分離手段によって分離された光を受光する光検出器
と、 前記光検出器の測定データに基づいて土壌の光学特性を
分析する手段と、 を備えた土壌の光学特性測定装置。2. A light source for irradiating the soil surface with measuring light having a plurality of wavelengths, a light trapping portion for trapping and confining the measuring light scattered and reflected by the soil surface, and a scattered reflection over a wide area of the soil surface. Collect the measured light,
Condensing means for guiding the light into the light capturing portion, means for separating the light in the light capturing portion for each different wavelength, a photodetector for receiving the light separated by the separating means, and measurement data of the photodetector And means for analyzing the optical characteristics of soil based on the above, and an optical characteristic measuring apparatus for soil comprising:
る略球状の空洞であることを特徴とする、請求項１又は
２に記載の土壌の光学特性測定装置。3. The soil optical characteristic measuring device according to claim 1, wherein the light trap is a substantially spherical cavity having an inner surface with high reflectance.
光捕捉部の受光窓に結像させることを特徴とする、請求
項１又は２に記載の土壌の光学特性測定装置。 4. The image of the soil surface is obtained by the light collecting means.
The soil optical characteristic measuring device according to claim 1 or 2, wherein an image is formed on a light receiving window of the light capturing portion .
部材で覆ったことを特徴とする、請求項１又は２に記載
の土壌の光学特性測定装置。5. The soil optical property measuring device according to claim 1, wherein a portion between the soil surface and the soil surface is covered with a light shielding member.
たり、投光方向から外れた位置へ取り除いたりできるよ
うにした、請求項１又は２に記載の土壌の光学特性測定
装置。6. The soil optical characteristic measuring device according to claim 1, wherein a reference plate is arranged in the light projecting direction from the light source, or the reference plate can be removed at a position deviated from the light projecting direction.
装置を備えた、請求項１又は２に記載の土壌の光学特性
測定装置。7. The soil optical characteristic measuring device according to claim 1, further comprising a measuring position measuring device for specifying a measuring position.
置情報と、前記光学特性分析手段により得られた測定デ
ータとから、土壌の特性マップを作成する手段を備え
た、請求項７に記載の土壌の光学特性測定装置。8. The method according to claim 7, further comprising means for creating a soil characteristic map from the position information output from the measuring position measuring device and the measurement data obtained by the optical characteristic analyzing means. Optical property measuring device for soil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25433197A JP3451535B2 (en) | 1997-09-02 | 1997-09-02 | Soil optical property measurement device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25433197A JP3451535B2 (en) | 1997-09-02 | 1997-09-02 | Soil optical property measurement device |
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| Publication Number | Publication Date |
|---|---|
| JPH1183627A JPH1183627A (en) | 1999-03-26 |
| JP3451535B2 true JP3451535B2 (en) | 2003-09-29 |
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ID=17263529
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US10701856B2 (en) | 2016-11-07 | 2020-07-07 | The Climate Corporation | Agricultural implements for soil and vegetation analysis |
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| EP1143784B1 (en) * | 1999-03-15 | 2007-02-21 | Tokyo University of Agriculture and Technology Tlo Co., Ltd. | Soil survey device and system for precision agriculture |
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| EP1203955A4 (en) * | 1999-07-08 | 2003-07-02 | Omron Tateisi Electronics Co | Soil measuring instrument, soil measurement assisting device and method, recorded medium on which program is recorded, recorded medium on which data is recorded, application amount controller, application amount determining device, method for them, and farm working determination assisting system |
| US6424416B1 (en) * | 1999-10-25 | 2002-07-23 | Textron Systems Corporation | Integrated optics probe for spectral analysis |
| US6836325B2 (en) | 1999-07-16 | 2004-12-28 | Textron Systems Corporation | Optical probes and methods for spectral analysis |
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| EP1484600A3 (en) | 2000-03-10 | 2006-11-02 | Textron Systems Corporation | Optical probes and methods for spectral analysis |
| JP2003042943A (en) * | 2001-08-01 | 2003-02-13 | Japan Atom Energy Res Inst | Spectrometry for high-speed signal |
| JP2006242891A (en) * | 2005-03-07 | 2006-09-14 | Tokyo Univ Of Agriculture & Technology | Device for measuring characteristics of soil |
| JP4991990B2 (en) * | 2007-03-28 | 2012-08-08 | 静岡県 | Plant growth stage determination method and system |
| CN101226143B (en) * | 2007-08-15 | 2011-01-05 | 武汉市天虹仪表有限责任公司 | Long optical path air monitoring instrument |
| DE102007058563A1 (en) * | 2007-11-30 | 2009-06-04 | Sentronic GmbH Gesellschaft für optische Meßsysteme | Spectrometer measuring head for analyzing characteristics of liquid, pasty or solid substances |
| JP6256345B2 (en) | 2012-10-26 | 2018-01-10 | ソニー株式会社 | Condensing unit, condensing method, and light detection system |
| SG10201902144RA (en) * | 2019-03-11 | 2020-10-29 | Housing And Dev Board | Apparatus, system and method for classification of soil and soil types |
| CN110346043A (en) * | 2019-06-03 | 2019-10-18 | 湖北富邦科技股份有限公司 | A kind of method of Fast Evaluation granulated fertilizer surface whiting degree |
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Non-Patent Citations (1)
| Title |
|---|
| Ｔｒａｎｓａｃｔｉｏｎｓ ｏｆ ｔｈｅ ＡＳＡＥ，１９９３年，ｖｏｌ．３６，ｐ．１５７１−１５８２ |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10701856B2 (en) | 2016-11-07 | 2020-07-07 | The Climate Corporation | Agricultural implements for soil and vegetation analysis |
| US11871691B2 (en) | 2016-11-07 | 2024-01-16 | Climate Llc | Agricultural implements for soil and vegetation analysis |
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| Publication number | Publication date |
|---|---|
| JPH1183627A (en) | 1999-03-26 |
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