JP3243039B2 - Calibration method of coaxial reflection type measuring device and coaxial reflection type measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention, by the transport conveyor
The present invention relates to a calibration method and a measuring device for an optical measuring device for measuring articles being transported at irregular intervals , and more particularly to a coaxial reflection in which a part of an optical axis of an illumination optical system and a part of an optical axis of a receiving optical system are coaxially arranged. The present invention relates to a calibration method for a type measuring device and a coaxial reflection type measuring device.

[0002]

2. Description of the Related Art Generally, an optical measuring device is offline.
Even in the mold, even in the online type, temperature, humidity,
The measurement accuracy may be degraded due to an environmental change due to dust or the like, or a temporal change in the characteristics of the lamp and the light receiving element, etc., and the measurement is performed after performing calibration in an environment in which the device is used. And the online type
Chi, calibration of an optical measuring device for measuring an article being transported at irregular intervals on the conveyor is equal to the measured article stopping the supply of articles onto or conveyor to stop the operation of the conveyor The calibration reference reflector was installed at the measurement position of, and the reflected light from the calibration reference reflector was taken in.

[0003]

According to the above-mentioned conventional calibration method, in order to calibrate, the operation of the transport conveyor is stopped or the supply of articles on the transport conveyor is stopped, and the measurement position on the transport conveyor is measured. That is, since the calibration reference reflector is provided on the conveyance path of the article to be measured, there has been a problem that the work of measuring the article has to be temporarily interrupted and the work efficiency is not improved. Furthermore, in order to stabilize the accuracy of the optical measuring device, it is necessary to carry out more calibrations. Since the operation was interrupted, there was a problem that the work efficiency was significantly reduced.

[0004] The problem to be trying to the present invention is resolved, transport
Calibration without interruption of measuring work of articles conveyed at irregular intervals on the conveyor , and highly reliable calibration
To provide a calibration method and a coaxial reflection-type measuring device for a coaxial reflection-type measuring device capable of improving work efficiency and improving measurement accuracy by performing calibration by obtaining data and performing many calibrations. It is in.

[0005]

In order to solve the above problems SUMMARY OF THE INVENTION The method of calibrating a coaxial reflection type measuring device of the present invention irradiates light toward the article to be conveyed at non constant frequency than the conveyor , Measurement data obtained by receiving the reflected light and storage
A calibration method of a coaxial reflection type measuring device for determining the reflection intensity or reflectance based on the stored calibration data to the means,
Arrange the light emitting and receiving ports of the coaxial reflection type measuring device and the calibration reference reflector so as to face each other with the transport conveyor interposed therebetween, and through the gap between the preceding article and the following article transported by the transport conveyor. The calibration reference reflector and the light emitting / receiving port face each other and the length of the gap is a predetermined value unless the length is equal to or less than a predetermined value.
JP updating stored in the storage means which obtains calibration data from the reflected light from the calibration reference reflector by each time calibration instruction signal issued predetermined time is larger than the value
It is a sign .

[0006] Coaxial reflection type measurement apparatus of the present invention irradiates light toward the article to be conveyed at non constant frequency than the transfer conveyor, and the measurement data obtained by receiving light reflected serial
A coaxial reflection type measuring device for determining the reflection intensity or reflectance based on the stored calibration data to憶means, disposed to face the light emitting and receiving port of the coaxial reflection type measuring device across the conveyor Calibration reference reflector, the calibration reference reflector and the light emitting and receiving port face each other via a gap between the preceding article and the following article conveyed by the conveyor.
And, unless the length of the gap is less than a predetermined value,
Wherein this if even larger to obtain calibration data from the reflected light from the calibration reference reflector out a predetermined time calibration instruction signal
And a control unit for updating and storing in the storage means .

[0007]

According to the present invention constructed as described above, an article is provided.
Is transported at irregular intervals by the transport conveyor.
During conveyance by the conveyor, when the calibration reference reflector and the light emitting and receiving port of the coaxial reflection type measuring device face each other via a gap between the preceding article and the following article to be conveyed , and
Except when the length of the gap is less than the specified value, it is larger than the specified value.
When the calibration instruction signal is issued for a predetermined period of time, the calibration data is obtained from the reflected light from the calibration reference
Since the storage means is updated and stored, the reflection intensity or reflectance of the light reflected from the article when the article is irradiated with light is the latest and calibration time updated and stored in the storage means during the transport of the article.
Is obtained based on highly reliable calibration data with no fluctuations .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view mainly showing an optical section P of a coaxial reflection type measuring apparatus according to the present invention. In the embodiment, fruits and vegetables S such as apples and peaches are used as the articles.

In the figure, an illumination optical system for irradiating a fruit or vegetable S with light includes a light source device 1, a condenser lens 2, a chopper 3,
A lens 4, a beam splitter 5, and an objective lens 6 are arranged along the optical axis. On the other hand, the light receiving optical system for out taking the reflected light from the fruits or vegetables S is the objective lens 6, beam splitter 5, a condenser lens 7, a slit 8, a spectrometer 9, test
The output device 11 is arranged along the optical axis.

Part of the optical axis of the illumination optical system and the optical axis of the light receiving optical system (the irradiation optical axis to the article S and the light receiving optical axis from the article S) are arranged on the same optical axis. .

The light source device 1 emits visible light and / or near-infrared light, or light in another wavelength region, and preferably emits light containing at least near-infrared light, such as a halogen lamp or an incandescent lamp. A light bulb or the like is used.

[0013] Beam splitter 5, the light of approximately 50% of the light incident from the light source device 1 is Ru is straight, and the remaining approximately 50% of the light has become so that is reflected in the 90 degree direction. And the light reflected in the 90-degree direction is the surface of the fruit and vegetable S
Irradiation is performed toward the substantially central portion of the. It should be noted that about 50% of the light traveling straight through the beam splitter 5 is absorbed by the light absorbing section 1.
It is led to 0 and disappears.

At least a part of the light reflected by the fruits and vegetables S enters the beam splitter 5 again through the objective lens 6, and about 50% of the incident light enters the slit 8 through the condenser lens 7. Go straight. Then, the remaining about 50% of the light is reflected in the 90-degree direction and goes to the light source device 1 and disappears naturally.

In this embodiment, a beam splitter is used. However, the present invention is not limited to this. For example, a half mirror or a polarizing beam splitter can be used, and can be appropriately selected according to the characteristics of the object to be measured. preferable.

The spectroscope 9 goes straight through the beam splitter 5 to split the light incident from the slit 8 to extract light in a specific wavelength range in the near infrared region and / or the visible region. This wavelength range may be narrow or relatively wide. When the spectroscope 9 is narrow, it is preferable to use an interference filter or the like. When the wavelength range is relatively wide, a diffraction grating type spectroscope or prism type is used. It is preferable to use a spectroscope.

Reference numeral 11 denotes a detection device which receives light from the spectroscope 9 and outputs an electric signal corresponding to the amount of received light. In FIG. 1, the spectroscope 9 is provided in the middle of the optical path between the beam splitter 5 and the detection device 11 to use a so-called post-spectroscopy system.
And a pre-spectroscopic method may be provided in the middle of the optical path. Furthermore,
As the lens or the reflecting mirror, an appropriate type can be used at an appropriate position in the optical path as needed.

The operation of the optical section P of the coaxial reflection type measuring device configured as described above will be described. Light emitted from the light source device 1 is collected by a condenser lens 2, a chopper 3, and a lens 4.
, The beam splitter 5 reflects about 50% of the incident light in the 90-degree direction, and causes the remaining 50% of the light to travel straight. 90
About 50% of the light reflected in the degree direction irradiates the substantially central portion of the surface of the fruit or vegetable S via the objective lens 6. Further, the remaining 50% of the light goes straight and is extinguished by the light absorbing unit 10.

When the reflected light from the fruits and vegetables S enters the beam splitter 5 again via the objective lens 6, about 50% of the light is reflected in the 90-degree direction and disappears toward the light source device 1. The remaining 50% of the light goes straight to the condenser lens 7,
The light enters the spectroscope 9 through the slit 8. Then, the spectroscope 9 disperses the incident light and extracts light in a specific wavelength range. The separated light in the specific wavelength range is detected by the detection device 11 and converted into an electric signal corresponding to the amount of received light.

As described above, the optical unit P of the coaxial reflection type measuring apparatus is configured such that the illumination optical system and the light receiving optical system are provided with an optical axis for irradiating the fruits and vegetables S with light and a light for extracting reflected light from the fruits and vegetables S. Since the axes are arranged on the same optical axis, the light emitting / receiving port M of the coaxial reflection type measuring device and the calibration reference reflection plate 13 are arranged to face each other with the transport conveyor 12 for transporting the fruits and vegetables S therebetween. Can be.

That is, by using the coaxial reflection type optical section P, the calibration reference reflection plate 13 is disposed behind the measurement surface of the article (outside the conveyor 12) if it is on the same optical axis. be able to. Thereby, calibration data can be obtained based on the light reflected from the same reference plane (reflection plate 13).

FIG. 2 is an explanatory view of an embodiment in which the coaxial reflection type measuring device of the present invention is used for a fruit and vegetable sorting device. In the drawing, P indicates the optical unit P described above, and the same reference numerals are given and the description is omitted.

[0023] 12 is a conveyor, the pan 14 which fresh produce S is placed which carry at indeterminate intervals one by one row, for example Chen conveyor or belt conveyor or the like conveying device is used. According to the drawing, the fruits and vegetables S
Is configured to be placed on the tray 14 and transported, but the invention is not limited to this, and the fruits and vegetables S may be transported directly on the transport surface.

Reference numerals 15a, 15b, and 15c denote discharge operation devices which engage with the tray 14 being conveyed to sort the tray 14 conveyed on the conveyor 12 out of the conveying process of the conveyor 12. Conveyor 1 from above
6 to be discharged. This discharge operation device 1
For 5, a sorting / discharging device described in, for example, JP-A-2-62313 can be used. The discharge operation device 15 is operated by a discharge command signal output from the control unit 20 described later.

Although the number of the discharge operation devices 15 is three in the drawing, the number is not limited to three but is determined according to the number of sorting classes of the fruits and vegetables S. Reference numeral 17 denotes an encoder device, which outputs a predetermined signal (pulse) for a predetermined movement amount of the transfer surface of the transfer conveyor 12.

[0026] The calibration reference reflector 13 is disposed so as to throw light receiving port M and the opposing coaxial reflection type measuring device across the third conveyance path of the transfer conveyor 12, as best shown in FIG., The When there is no article S on the conveyance path between the opposing members, light emitted from the light source 1 via the beam splitter 5 and the like is reflected by the reflection plate 13, and the reflected light enters the light emitting / receiving opening M. I have.

Reference numeral 18 denotes an article sensor,
The transport direction 2 is provided upstream of the light emitting / receiving port M, that is, at a position along the transport path of the transport conveyor 12 upstream of the measurement position, and detects the presence or absence of fruits and vegetables S transported by the transport conveyor 12. The detection signal is output to the control unit 20.

The control unit 20 of the coaxial reflection type measuring device has a second
As shown in the figure, a signal from the detection device 11, a signal from the article sensor 18, and the encoder device 17
, The quality and characteristics of the fruits and vegetables S are determined, and a discharge signal for sorting is output to the corresponding discharge operation device 15 based on the result of the determination. A block diagram in FIG. 2 showing an outline of a circuit of the control unit 20 will be described.

Reference numeral 21 denotes an input / output device (I / O); 22, a central processing unit (CPU) for controlling the entire device; 23, a random access memory (RAM) used as a working area; (Program), a read-only memory (ROM) in which setting values and the like are written in advance, and 25 is a bus line to which the above circuits are connected. The operation of the control unit 20 will be described with reference to FIG.

FIGS. 4 (a), 4 (b) and 4 (c) are time charts showing output timings of the measurement instruction signal B and the calibration instruction signal C for the detection signal A of the fruits and vegetables S by the article sensor 18. is there. That is, FIG.
4 (b) shows an output waveform of the waveform immediate indication signal B, and FIG. 4 (c) shows an output waveform of the calibration indication signal C. 4 (b) and (c) in FIG.
In contrast to (a), the fruits and vegetables S on the conveyor 12 are the goods.
Repeat for the time from the position of the sensor 18 to the position of the light emitting / receiving port M
It is shown up.

The control unit 20 converts a detection signal from the article sensor 18 and a signal from the encoder device 17 into I / O2
1, the CPU 22 inputs the length (time) of the fruits and vegetables S in the transport direction and the length of the gap (time) between the preceding fruits and vegetables S based on the input signals. ) Is calculated to determine the timing at which measurement and calibration are performed at a predetermined measurement position, and the signals (measurement instruction signal B and calibration instruction signal C) at the determined timing are used to calculate I.
Data (measurement data, calibration data) is obtained from an electric signal corresponding to the amount of light received from the detection device 11 at / O21.

The measurement instruction signal B corresponds to the middle part of the length of the detection signal A in the time direction as shown in FIG. 4 (b).
Is output for a predetermined time , that is,
The calibration instruction signal C is output for a predetermined time when the central portion arrives at the measurement position, and the calibration instruction signal C is output first after the detection signal A output as shown in FIG. A predetermined time corresponding to a predetermined position (gap) between the output detection signal A and the detection signal A
It is output, ie fruit or vegetable S of the previous row arrives at the measuring position
From the point where the trailing edge passes the position,
Predetermined (gap) until the front end arrives at the measurement position
The position is output for a predetermined time . This calibration instruction signal C is preferably such that the following fruit or vegetable S is at the measurement position.
It is preferable to output for a predetermined time just before the arrival .
Further, the calibration instruction signal C when the gap as the gap between the detection signal A3 and A4 as shown in Figure is less than a predetermined value (the predetermined time) is not output. Therefore, as the calibration data in this case, data obtained based on the calibration instruction signal C3 immediately before the detection signal A3 is used. As shown in the figure,
Like the gap between the detection signals A1 and A2 and A2 and A3,
If the gap is larger than a predetermined value (the predetermined time),
Correct instruction signals C2 and C3 are output for a predetermined time.

The reflected light fetched from the calibration reference reflector 13 is received by the detector 11 and converted into an electric signal corresponding to the amount of light received and sent to the I / O 21.
Numeral 22 fetches an electric signal from the I / O 21 according to the calibration instruction signal C to obtain calibration data. Then, the calibration data is updated and stored in the RAM 23 as storage means of the control unit 20.

On the other hand, the reflected light taken from the fruits and vegetables S is
The light is received by the detection device 11, converted into an electric signal corresponding to the amount of received light, and sent to the I / O 21 as described above.
U22 fetches an electric signal from the I / O 21 in response to the measurement instruction signal B to obtain measurement data, and based on the measurement data and the calibration data updated and stored in the RAM 23, determines the reflectance or reflection intensity at a specific wavelength. calculate.

Further, the CPU 22 determines the quality and characteristics of the fruits and vegetables S based on the data on the quality and characteristics set in the setting circuit (not shown) or the RAM 23 from the calculation result of the reflectance or the reflection intensity of the specific wavelength. . The data relating to the quality and characteristics may be, for example, data (model formula, etc.) relating to the ripeness, sugar content or hardness of the standard fruits and vegetables whose quality and characteristics are known.

Further, the sorting control circuit (not shown) of the control unit 20 transfers the determined fruits and vegetables S to the discharge operation device 15 corresponding to the determination results based on the quality and characteristic determination results. Then, a discharge command signal for operating the discharge operation device 15 is output via the I / O 21. As a result, the fruits and vegetables S transferred on the transport conveyor 12 can be discharged onto the unloading conveyor 16 together with the receiving tray 14 by operating the discharge operation device 15 at the corresponding sorting position.

FIG. 5 shows an example in which the article sensor 18 is provided at a predetermined distance downstream of the light emitting / receiving port M of the coaxial reflection type measuring device with respect to the conveying direction of the conveyor 12. The positional relationship between the article sensor 18 and the light emitting / receiving port M of the coaxial reflection type measuring apparatus is such that when the front end of the fruit or vegetable S is detected by the article sensor 18 as shown in the figure, the coaxial reflection type measuring apparatus is moved to substantially the center of the vegetable S. Is to be measured. In this case, the encoder device 17 can be omitted.

FIGS. 6 (a), (b), (c), (d)
FIG. 6 is a time chart showing output timings of a measurement instruction signal B and a calibration instruction signal C with respect to the detection signal A of the fruits and vegetables S in FIG. FIG. 6A is a diagram showing the position of the fruit or vegetable S when the measurement instruction signal B is output. FIG. 6B shows an output waveform of the detection signal A of the fruit and vegetable S. FIG. 6C shows an output waveform of the measurement instruction signal B. FIG. 6D shows the output waveform of the calibration instruction signal C.

As shown in the figure, the measurement instruction signal B is output for a predetermined time every time the detection signal A rises. That is, it is output each time the front end of the fruit or vegetable S is detected by the article sensor 18. The calibration instruction signal C is output for a predetermined time immediately after the output of the detection signal A stops. That is, when the fruits and vegetables S pass through the article sensor 18, the output is made immediately after that.

If the gap between the preceding fruits and vegetables S and the following fruits and vegetables S is larger than a predetermined value (the predetermined time) ,
Each time it outputs a calibration instruction signal C for a predetermined time, contrary to the detection signal A2 that gap predetermined value as the gap between A3
In the case of (the predetermined time) or less , the calibration instruction signal C is output, but the interruption is canceled by the input of the detection signal A3. Therefore, the calibration data in this case is the calibration instruction signal C2 immediately before the detection signal A2. The data obtained based on this is used.

[0041]

According to the present invention, as described above, the conveyor
Irradiates light to articles conveyed at irregular intervals
Measurement data obtained by receiving the reflected light
Reflection intensity or reflection based on calibration data stored in the column
Coaxial reflection type measuring device or this coaxial reflection type meter
In the method of calibrating a measuring device, the light emitting and receiving port of the coaxial reflection type measuring device and the calibration reference reflector are arranged so as to face each other with the transport conveyor interposed therebetween, and the preceding article transported by the transport conveyor and the rear The calibration base through the gap between the
The quasi-reflector and the light emitting / receiving port face each other and the length of the gap is
Except when the value is less than the specified value,
The reflected light from the calibration reference reflector is fetched by a calibration instruction signal issued each time for a predetermined time, calibration data is obtained from the reflected light, and this is updated and stored in the storage means. Since the reflectance or reflection intensity of the article is determined based on the calibration data obtained,
Calibration is performed during the transfer of goods without stopping the operation of the conveyor or stopping the supply of goods for calibration even though the goods are conveyed at intervals, and without interrupting the measurement of the goods. such Ukoto can, moreover, is a variation in the calibration time
Calibration data can be obtained in time without
Calibration can be performed using highly reliable configuration data, and
Since the calibration can be performed frequently, there is an effect that the efficiency of the measurement work of the article and the measurement accuracy can be greatly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view mainly showing an optical unit of a coaxial reflection type measuring apparatus according to the present invention .

FIG. 2 is an explanatory view of an embodiment in which the present invention is used in a fruit and vegetable sorting apparatus.

FIG. 3 is an explanatory view showing a state where a calibration reference reflector and a light emitting and receiving port face each other via a gap.

4 (a), 4 (b) and 4 (c) show a detection signal A
FIG. 7 is a time chart showing output timings of a measurement instruction signal B and a calibration instruction signal C with respect to FIG.

FIG. 5 is an explanatory diagram of another example of a mounting position of the article sensor 18.

6 (a), 6 (b), 6 (c) and 6 (d) are time charts showing output timings of a measurement instruction signal B and a calibration instruction signal C with respect to the detection signal A in FIG. It is.

[Explanation of symbols]

1: Light source device 2: Condensing lens 3: Chopper 4: Lens 5: Beam splitter 6: Objective lens 7: Condensing lens 8: Slit 9: Spectroscope 10: Light absorbing unit 11: Detector 12: Transport conveyor 13: Calibration reference reflector 14: Receiving tray 15 , 15a, 15b, 15c : Discharge actuator 16 , 16a, 16b, 16c : Discharge conveyor 17: Encoder device 18: Article sensor 20: Control unit 21: I / O 22: CPU 23 : RAM 24: ROM 25: Bus line S: Fruits and vegetables M: Light emitting and receiving port P: Optical part A: Detection signal B: Measurement instruction signal C: Calibration instruction signal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-50344 (JP, A) JP-A-4-115142 (JP, A) Fully open 49-94684 (JP, U) Really open 1959 194047 (JP, U) Japanese Utility Model Hei 5-90353 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/84-21/958 G01J 1/00-1/60 G01N 21/17-21/61

Claims (2)

(57) [Claims] [Claim 1] irradiating light toward the article to be conveyed at non constant frequency than the conveyor, resulting et receives the reflected light
A calibration method of a coaxial reflection type measuring device for determining the reflection intensity or reflectance based on the stored calibration data to the measurement data storage means, the light projecting and receiving of a coaxial reflection type measuring device across the conveyor The mouth and the calibration reference reflector are arranged to face each other, and the calibration reference reflector and the light emitting and receiving port face each other through a gap between the preceding article and the following article conveyed by the conveyor. And the length of the gap is a predetermined value
Except in the following cases, each time it is larger than the specified value
Calibration method of a coaxial reflection type measuring device, characterized by <br/> updated and stored in the storage means which obtains calibration data from the reflected light from the calibration reference reflector by the calibration instruction signal issued constant time. Wherein irradiating light toward the article to be conveyed at non constant frequency than the conveyor, resulting et receives the reflected light
A coaxial reflection type measuring device for determining the reflection intensity or reflectance based on the calibration data stored in the measured data storage means that, the light emitting and receiving port facing the coaxial reflection type measuring device across the conveyor a calibration reference reflection plate disposed so as to opposes the the calibration reference reflecting plate and the light emitting and receiving port through the gap between the articles of the trailing and leading of articles conveyed by the conveyor and the When the gap length is less than the specified value
If it is larger than the specified value, the calibration
And a controller for obtaining calibration data from reflected light from the calibration reference reflector and updating and storing the calibration data in the storage means .