JP2006242891A - Device for measuring characteristics of soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring the characteristics of soil, capable of collecting a lot of data from one measurement point at a high speed, while eliminating the influence of disturbance light. <P>SOLUTION: Inspection light emitted from an illuminating section 10a toward the soil is reflected by the soil and received by a light-receiving section 20a. Reflection light received by the light-receiving section is separated into many reflected light beams by a separating means 22, and the values of prescribed wavelength intensity of respective refected light beams are detected by detectors 27, 29 and 31. Furthermore, an intermittent means 12 is employed, which intermits the irradiation of the inspection light. Each detector has a signal processing means 41, which removes the intensity of the disturbance light received by the light-receiving section, when the irradiation of the inspection light is intermitted, from the intensity of the reflected light, received by the light-receiving section when the irradiation of the inspection light is carried out. Since many true intensity values of the reflected light, from which the influences of the disturbance light are eliminated, can be collected at one measurement point, many accurate data sets can be collected from a large number of measurement points, respectively, while making a chisel section in the soil advance at a high speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a soil property measuring apparatus that measures soil properties, and more particularly, to a soil property measuring device that measures soil properties by advancing a chisel portion in the soil.

Conventionally, as a soil property measuring device, an irradiation unit that is provided in a chisel portion and irradiates soil with inspection light, a light receiving portion that is provided in the chisel portion and receives reflected light from the soil, and the light receiving portion receives light. A branching means for branching the reflected light into a plurality of light sources and a detector for detecting the intensity of each reflected light branched by the branching means for each predetermined wavelength, and the characteristics of the soil are improved while the chisel portion is advanced in the soil. What was measured is known (patent document 1, patent document 2).
The chisel portion is generally provided in a traveling frame, and the chisel portion can be advanced in the soil by pulling the traveling frame with a tractor.

Conventionally, a soil property measuring apparatus provided with an intermittent means for intermittently irradiating the inspection light in order to eliminate the influence of disturbance light is also known (Patent Document 3).
In this soil property measuring apparatus, when the irradiation of the inspection light is interrupted, the intensity of the light received by the light receiving unit, that is, the intensity of the disturbance light is measured, and when the inspection light is irradiated to the soil The intensity of the disturbance light is removed from the intensity of the reflected light received by the light receiving unit.
JP 2003-139765 A Japanese Patent No. 3451535 Japanese Patent No. 3451536

In recent years, more detailed data on soil characteristics has been demanded, and it has become common to require nine or more types of data at one measurement point.
However, in the conventional apparatus, it was not possible to collect a large number of data at a single measurement point at a high speed while eliminating the influence of ambient light that changes with the progress of the chisel portion.
In view of such drawbacks, the present invention provides a soil property measuring apparatus capable of collecting a large number of data at one measurement point at high speed while eliminating the influence of disturbance light.

That is, the invention of claim 1 is provided with an irradiation unit that is provided in the chisel portion and irradiates the soil with inspection light, a light receiving portion that is provided in the chisel portion and receives reflected light from the soil, and the light receiving portion receives light. A branching means for branching the reflected light into a plurality of light sources and a detector for detecting the intensity of each reflected light branched by the branching means for each predetermined wavelength, and the characteristics of the soil are improved while the chisel portion is advanced in the soil. In the soil property measuring device to measure,
In addition to providing intermittent means for intermittently irradiating the inspection light, the detector is provided for each reflected light branched by the branch means, and the detector receives light when the inspection light is irradiated to each detector. The signal processing means is provided for removing the intensity of disturbance light received by the light receiving unit when the irradiation of the inspection light is interrupted from the intensity of the reflected light received by the unit.

According to the invention of claim 1, when the inspection light is irradiated onto the soil from the irradiation unit, the reflected light from the soil is received by the light receiving unit. Then, the reflected light received by the light receiving unit is branched into a plurality of parts by the branching means and enters each detector. Therefore, a large number of data can be collected at one measurement point by branching the reflected light by the required number.
In addition, an intermittent means for interrupting the irradiation of the inspection light is provided, and the irradiation of the inspection light is interrupted by the intensity of the reflected light received by the light receiving unit when each of the detectors is irradiated with the inspection light. Since the signal processing means for removing the intensity of the disturbance light received by the light receiving unit at the time is provided, the influence of the disturbance light can be eliminated by each signal processing means. And since this signal processing means is provided in each detector, each reflected light branched into a plurality can be processed at the same time, so even when collecting a large number of data, as a whole It can be processed at high speed.
As a result, it is possible to collect a large number of highly accurate data at a large number of measurement points while the chisel portion is advanced in the soil at a high speed.

The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, a chisel portion 1 of a soil property measuring apparatus is connected to a traveling frame F via a beam 2, and this traveling frame F is used as a working vehicle such as a tractor T. The chisel part 1 can be made to advance in the soil by being pulled by.
As shown in FIG. 2, the tip portion of the chisel portion 1 is a soil penetration portion 1a, and a flat plate 3 is provided at the bottom of the intermediate portion between the tip end and the rear end 1b of the chisel portion 1. Along with advancement of the tractor T, a hole is made in the soil by the soil penetration portion 1a, and the soil observation surface 4 can be created by leveling the lower surface of the hole with the leveling plate 3.
A measuring unit 5 for measuring the characteristics of the soil is provided behind the leveling plate 3 and inside the chisel portion 1, and an observation space 6 is formed between the measuring unit 5 and the soil observation surface 4. Like to do.

The measuring unit 5 is provided with an irradiating unit 10a serving as one end of the illumination optical fiber 10, and the other end of the illumination optical fiber 10 is drawn to the ground via the inside of the beam 2 and travels as described above. The light source 11 provided in the frame F is opposed to the light source 11 through intermittent means 12 such as a rotary light chopper.
The intermittent means 12 includes a rotating plate 13, a window 14 formed in the rotating plate 13, and a motor 15 that rotationally drives the rotating plate 13, and the rotating plate 13 is connected to the other end of the optical fiber 10 for illumination. Between the light source 11 and the light source 11.
Therefore, if the rotating plate 13 is rotated by the motor 15 while the light source 11 is turned on, the inspection light from the light source 11 passes through the window 14 of the rotating plate 13 and passes through the irradiation unit 10a of the optical fiber 10 for illumination. Or is blocked by the rotating plate 13 and does not irradiate the soil.
As another example of the intermittent means 12, the light source 11 itself may be blinked.

The measuring unit 5 is provided with a light receiving unit 20a that is one end of the branch condensing fiber 20, and the inspection light applied to the soil from the irradiation unit 10a is reflected by the soil, and the reflected light is received by the light receiving unit 20a. The unit 20a can receive light.
The other end of the branch concentrating fiber 20 is drawn to the ground via the inside of the beam 2 and connected to a detection device 21 provided on the traveling frame F.
The branching and collecting fiber 20 constitutes a part of the branching means 22 that branches the reflected light received by the light receiving unit 20a into a plurality of parts. In the illustrated embodiment, the reflected light can be branched into three. It is.
Further, the branching means 22 has two dichroic mirrors 23 in order to branch the reflected light from each of the branched optical fibers branched into three in addition to the branched optical fibers 20, respectively. 24. A beam splitter may be used instead of the dichroic mirrors 23 and 24.

The reflected light emitted from one branching and collecting fiber 20 is transmitted through the collimating lens 25 to be a parallel light beam, and then sequentially transmitted through the dichroic mirrors 23 and 24. Each dichroic mirror 23, Each of them is branched into two when passing through 24.
The reflected light that has passed through the two dichroic mirrors 23 and 24 passes through the interference filter 26 and is detected by the detector 27.
On the other hand, the reflected light reflected by the first dichroic mirror 23 is transmitted through the interference filter 28 and detected by the detector 29, and the reflected light transmitted through the dichroic mirror 23 and reflected by the next dichroic mirror 24 is reflected by the interference filter. 30, and is detected by the detector 31.
Each of the interference filters 26, 28, and 30 is set so as to transmit a specific wavelength. Therefore, the detectors 27, 29, and 31 can detect the intensity of reflected light having a specific wavelength. It is like that.
The reflected light emitted from the remaining two branched condensing fibers 20 is also branched into three in the same manner as described above. Therefore, in this embodiment, each intensity of the reflected light having a total of nine wavelengths is different. Can be detected.
Of course, the reflected light can be branched into 10 or more as required. Although not shown, the measuring unit 5 includes a soil displacement sensor for detecting the distance between the soil observation surface 4 and the irradiation unit 10a and the light receiving unit 20a in addition to the irradiation unit 10a and the light receiving unit 20a, a CCD color camera, A thermometer is provided.

Further, an encoder 40 is attached to the motor 15 constituting the intermittent means 12, and signals from the encoder 40 are input to a total of nine signal processing means 41 provided in the detectors 27, 29 and 31, respectively. I am letting.
Each signal processing means 41 can detect the rotation angle position of the rotating plate 13 based on the signal from the encoder 40, and therefore whether the inspection light from the light source 11 has passed through the window 14 or is blocked by the rotating plate 13. It can be done.
Each signal processing means 41 stores the intensity of the light detected by each detector 27, 29, 31 as the intensity of disturbance light when the inspection light from the light source 11 is blocked by the rotating plate 13. It has become.
On the other hand, when the inspection light from the light source 11 passes through the window 14 and is applied to the soil, the intensity of the disturbance light is excluded from the intensity of the reflected light detected by the detectors 27, 29, and 31. In addition, it is possible to obtain the intensity of the true reflected light excluding the influence of disturbance light. And the intensity | strength of the true reflected light obtained by each signal processing means 41 is memorize | stored in the memory | storage device which is not shown with data, such as a collection place. The data of the sampling location can be obtained by, for example, a GPS (see FIG. 1) provided on the traveling frame.

Data collected by the soil property measuring device includes MC (water), SOM (soil organic matter), TC (total carbon), TN (total nitrogen), carbon dioxide content, pH, CEC (cation exchange coefficient), etc. Can be mentioned.
Then, the absorbance of each wavelength (how much is absorbed by the soil) is detected from the received reflected light. At this time, in the relationship between the wavelength and the absorbance, the absorbance level for each substance is verified in advance, and the amount of the substance contained can be estimated from the absorbance at the characterized wavelength.
In addition, the substance amount is estimated from a plurality of wavelengths. For example, wavelengths of 1230 nm, 1450 nm, and 1650 nm are used to estimate MC (water), and MC (%) = 10.97 * Abs (1320 nm) + 194.54 * Abs (1450 nm) −234.74 * Abs ( 1650 nm) -11.70, the water content is estimated. Abs (1320 nm) indicates absorbance at a wavelength of 1320 nm.
By selecting appropriate interference filters 26, 28, and 30 for these wavelengths, arbitrary wavelengths can be detected in the range of, for example, ultraviolet light to mid-infrared light.

As described above, it is necessary to collect a large number of data at one measurement point. In the present embodiment, the reflected light collected at one measurement point is branched into nine detections. Since the data is input to the detectors 27, 29, and 31, data can be quickly collected by the detectors 27, 29, and 31.
In addition, since each of the detectors 27, 29, and 31 is provided with the signal processing means 41, each signal processing means 41 can quickly detect the intensity of the true reflected light from which the influence of disturbance light is eliminated. it can. Therefore, it is possible to collect a large number of highly accurate data at a large number of measurement points while the chisel portion 1 is advanced at high speed in the soil.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the dichroic mirrors 23 and 24 in the first embodiment are omitted, and instead, a plurality of reflected lights are formed only by the branching and collecting fiber 50. For example, it is made to branch into nine.
Therefore, in this embodiment, the branching and collecting fiber 50 constitutes the branching means 22, and the reflected light received by the light receiving unit 50 a that is one end of the branching and collecting fiber 50 is divided into nine by the branching and collecting fiber 50. A specific wavelength selected by the interference filter 26 which is branched and transmitted through the collimator lens 25 is input to each detector 27.
Other configurations are the same as those of the first embodiment, and the same or corresponding portions are denoted by the same reference numerals as those of the first embodiment.
In this embodiment, the same effect as that of the first embodiment can be obtained. In particular, since the dichroic mirror is not used in this embodiment, the optical system is simplified, adjustment is unnecessary, and there is an advantage that it is strong against mechanical vibration.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, a single condensing fiber 60 is used, and the reflected light received by the light receiving portion 60a as one end portion thereof is a concave diffraction grating. 61 is irradiated.
An array of many detectors 27 are arranged toward the diffraction grating 61, and a signal processing means 41 is provided for each detector 27.
The reflected light applied to the diffraction grating 61 is continuously branched from a short wavelength to a long wavelength by the diffraction grating 61, and the other ones from the detectors 27 on one end side in a number of detectors arranged in an array. The signal is input to the detector 27 on the end side. Therefore, in this embodiment, the diffraction grating 61 constitutes the branching means 22 that branches the reflected light received by the light receiving unit 60a into a plurality of parts.
And each detector 27 is provided with the signal processing means 41 similarly to the above-mentioned Example, Therefore The effect similar to the said Example can be obtained also in a present Example.

FIG. 5 shows a modification of the above-described third embodiment. In this embodiment, a condensing fiber 62 is provided for each detector 27, and a light receiving portion 62a of each condensing fiber 62 is a diffraction grating 61. It is positioned and fixed at a required position.
In the present embodiment, the reflected light irradiated by the diffraction grating 61 is received by the light receiving portion 62 a of each condensing fiber 62 and is input to each detector 27. At this time, since the light receiving portion 62a of each condensing fiber 62 is positioned at a required position, the required wavelength among the wavelengths continuously branched from the short wavelength to the long wavelength by the diffraction grating 61 is determined. The light can be selected and received by each light receiving portion 62a.
Also in the present embodiment, each detector 27 is provided with the signal processing means 41 as in the above-described embodiment, so that the same effect as the above embodiment can be obtained.

  In all of the above embodiments, an optical fiber is used, but it is needless to say that a relay optical system using a light pipe, a lens or a mirror may be used.

The side view which shows the whole soil characteristic measuring apparatus which concerns on this invention. 1 is a schematic configuration diagram showing a first embodiment of the present invention. The schematic block diagram which shows 2nd Example of this invention. The schematic block diagram of the principal part which shows 3rd Example of this invention. The schematic block diagram of the principal part which shows 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chisel part 4 Soil observation surface 10 Illumination optical fiber 10a Irradiation part 12 Intermittent means 22 Branch means 20, 50 Branch condensing fiber 61 Diffraction grating 20a, 50a, 60a Light receiving part 41 Signal processing means 23, 24 Dichroic mirrors 27, 29 31 detector

Claims (4)

An irradiation unit that is provided in the chisel part and irradiates the soil with inspection light, a light receiving part that is provided in the chisel part and receives reflected light from the soil, and a branch that branches the reflected light received by the light receiving part into a plurality of parts And a soil property measuring apparatus that measures the properties of the soil while proceeding in the chisel portion in the soil, and a detector that detects the intensity of each reflected wavelength branched by the branching device.
In addition to providing intermittent means for intermittently irradiating the inspection light, the detector is provided for each reflected light branched by the branch means, and the detector receives light when the inspection light is irradiated to each detector. A soil property measuring apparatus comprising a signal processing means for removing the intensity of disturbance light received by the light receiving unit when the irradiation of the inspection light is interrupted from the intensity of the reflected light received by the unit.   The soil property measuring apparatus according to claim 1, wherein the branching unit includes a branching and collecting fiber that branches the reflected light received by the light receiving unit into a plurality of branches.   The branching unit includes a branching and collecting fiber that branches the reflected light received by the light receiving unit into a plurality of parts, and a dichroic mirror or a beam splitter that branches the reflected light from each branching and collecting fiber into a plurality of parts. The soil property measuring apparatus according to claim 1.   The soil property measuring apparatus according to claim 1, wherein the branching unit includes a diffraction grating that causes reflected light to enter each detector.

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