JPH06258225A - Calibration method for coaxial reflecting type measuring device and coaxial reflecting type measuring device - Google Patents

Abstract

PURPOSE:To carry out multiple calibration without any interruption of measuring work so as to improve operability by acquiring calibration data from a calibration reference reflecting plate via a clearance between articles transported by a conveyor. CONSTITUTION:A transporting conveyor 12 transports pans 14, on each of which an article S is mounted, one by one. The light from a light source 1 irradiates the surface of the article S via a condensing lens 2, a chopper 3, a lens 4, a beam splitter 5, and an objective lens 6. The reflected light is incident on a spectroscope 9 via the lens 6, the splitter 5, the condensing lens 7, and a slit 8. The spectroscope 9 takes out the light in the specific wave length range, and the light is converted into an electric signal by a detecting device 11 and is outputted to a control part, 20. When a calibration reference reflecting plate 13 and a light projecting/receiving port M face each other via the clearance between a preceding article S and a following article S, which are transported by the conveyor 12, calibration data is found on the basis of the reflected light from the reflecting plate 13 and is renewed and stored. Therefore, a measurement value is found on the basis of the latest calibration data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration method and a measuring device for an optical measuring device for measuring an article being transferred by a conveyor, and more specifically, it relates to an optical axis of an illumination optical system and an optical axis of a light receiving optical system. The present invention relates to a method for calibrating a coaxial reflection type measurement device and a coaxial reflection type measurement device, a part of which is arranged coaxially.

[0002]

2. Description of the Related Art In general, an optical measuring device may be deteriorated in measurement accuracy due to environmental changes due to temperature, humidity, dust or the like or changes in characteristics of a lamp, a light receiving element and the like with time. The measurement is performed after calibrating in the environment. On the other hand, the calibration of the optical measuring device that measures the articles transferred on the conveyor is
A reference reflector for calibration is installed at the measurement position of the measured article by stopping the operation of the conveyor or stopping the supply of articles on the conveyor, and the reflected light from this reference reflector for calibration is set. It was something that was taken in.

[0003]

According to the above-mentioned conventional calibration method, in order to calibrate, the operation on the transport conveyor is stopped, or the supply of articles to the transport conveyor is stopped, and the measurement on the transport conveyor is performed. Since the calibration reference reflection plate is installed at the position, that is, on the conveyance path of the article to be measured, there is a problem that the measurement work of the article must be temporarily interrupted and the work efficiency does not increase. Furthermore, in order to stabilize the accuracy of the optical measuring device, it is necessary to carry out more calibrations. However, frequent calibration work by this conventional method means that the measurement work of articles is frequent. Since it is also interrupted, there was a problem that the work efficiency was significantly reduced.

The problem to be solved by the present invention is to improve the work efficiency and the measurement accuracy by performing the calibration without interrupting the measurement work of the article and by performing the calibration many times. An object of the present invention is to provide a method for calibrating a coaxial reflection type measurement device and a coaxial reflection type measurement device.

[0005]

In order to solve the above-mentioned problems, a method for calibrating a coaxial reflection type measuring apparatus according to the present invention irradiates an article conveyed by a conveyer at regular intervals or irregular intervals with light. A method for calibrating a coaxial reflection type measurement device which receives the reflected light and obtains the reflection intensity or reflectance based on the calibration data, wherein the coaxial reflection type measurement device is provided with a light emitting / receiving port and a calibration port for sandwiching the conveyor. A reference reflector is disposed so as to face each other, and the calibration reference reflector and the light emitting / receiving port face each other through a gap between a preceding article and a subsequent article conveyed by a conveyer and a calibration instruction signal. The calibration data is obtained from the reflected light from the calibration reference reflector and updated and stored every time when is issued.

Further, the coaxial reflection type measuring apparatus of the present invention irradiates the articles conveyed by the conveyer at regular intervals or irregular intervals with light, receives the reflected light, and reflects intensity or reflection on the basis of the calibration data. A coaxial reflection type measuring device for obtaining a rate, wherein a calibration reference reflection plate arranged to face the light emitting / receiving port of the coaxial reflection type measuring device with the conveying conveyor interposed therebetween, and the preceding conveyed by the conveying conveyor. Means for obtaining the calibration data from the reflected light from the calibration reference reflector and updating and storing the calibration data when the calibration reference reflector and the light emitting / receiving port face each other through the gap between the article and the subsequent article. It is characterized by having and.

[0007]

According to the present invention configured as described above, the calibration reference reflector and the light emitting / receiving unit of the coaxial reflection type measuring device are provided through the gap between the preceding article and the following article conveyed by the conveyor. When the mouth is opposed, calibration data is obtained from the reflected light from the calibration reference reflector and the data is updated and stored, so the reflection intensity or reflectance of the reflected light from the article when the article is irradiated with light is: It is obtained based on the latest calibration data that is updated and stored during the transportation of the article.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view mainly showing the optical section P of the 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 article.

In the drawing, an illumination optical system for irradiating the fruits and vegetables S with light is a light source device 1, a condenser lens 2, a chopper 3,
The lens 4, the beam splitter 5, and the objective lens 6 are arranged along the optical axis. On the other hand, the light receiving optical system for extracting the reflected light from the fruits and vegetables S is configured by arranging the objective lens 6, the beam splitter 5, the condenser lens 7, the slit 8 and the spectroscope 9 along the optical axis.

A part of the optical axis of the illumination optical system and the optical axis of the light receiving optical system (the optical axis of irradiation to the article S and the optical axis of received light 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 other wavelength regions, 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.

In the beam splitter 5, about 50% of the light entering from the light source device 1 goes straight, but the remaining about 5%.
0% of the light is reflected in the direction of 90 degrees. The light reflected in the 90 degree direction is directed toward the fruits and vegetables S. About 50% of the light that travels straight through the beam splitter 5 is guided to the light absorbing portion 10 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. The remaining about 50% of the light is reflected in the direction of 90 degrees, goes toward the light source device 1, and is naturally extinguished.

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

The spectroscope 9 is designed to go straight through the beam splitter 5 and split the light incident from the slit 8 to take out 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. If the spectroscope 9 is narrow, an interference filter or the like may be used. If it is relatively wide, a diffraction grating spectroscope or prism type may be used. It is better to use a spectroscope.

Reference numeral 11 is a detector, which receives the 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 optical path between the beam splitter 5 and the detection device 11 to form a so-called post-spectroscopic system, but the light source device 1 and the beam splitter 5 are used.
A pre-spectroscopic system may be provided by providing it in the optical path of the above. Furthermore,
As the lens or the reflecting mirror, an appropriate type can be used at an appropriate place 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 a condenser lens 2, a chopper 3, and a lens 4.
When incident on the beam splitter 5 via the beam splitter 5, about 50% of the incident light is reflected in the direction of 90 degrees, and the remaining 50% of the light is made to go straight. 90
About 50% of the light reflected in the degree direction illuminates the surface of the fruit S through the objective lens 6. The remaining 50% of the light travels straight and is extinguished in the light absorbing portion 10.

When the reflected light from the fruits and vegetables S is incident on the beam splitter 5 again through the objective lens 6, about 50% of the reflected light is reflected in the direction of 90 degrees and goes to the light source device 1 to disappear. The remaining 50% goes straight and enters the spectroscope 9 through the condenser lens 7 and the slit 8. And the spectroscope 9
Disperses 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 section P of the coaxial reflection type measuring apparatus has the optical axis for irradiating the fruits and vegetables S with light and the light for extracting reflected light from the fruits and vegetables S in the illumination optical system and the light receiving optical system. Since the axis is arranged on the same optical axis, the light emitting / receiving port M of the coaxial reflection type measuring device and the calibration reference reflecting plate 13 should be arranged so as to face each other with the conveyor 12 for conveying the fruits and vegetables S interposed therebetween. You can

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

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

A conveyer 12 conveys the trays 14 on which the fruits and vegetables S are placed one by one in a row at regular or irregular intervals. For example, a conveyer such as a chain conveyer or a belt conveyer is used. Although the fruits and vegetables S are placed on the tray 14 and transported according to the drawing, the present invention is not limited to this, and the fruits and vegetables S may be directly transported on the transport surface.

Denoted at 15a, 15b and 15c are discharge actuating devices, which are engaged with the receiving tray 14 being conveyed in order to sort the receiving tray 14 conveyed on the conveying conveyor 12 out of the conveying step of the conveyer 12. Carry-out conveyor 1 from above
6 is to be discharged upward. This discharge actuating device 1
As the No. 5, for example, the assortment discharging device described in JP-A-2-62313 can be used. The discharge operating device 15 is operated by a discharge command signal output from the control unit 20 described later.

Although the number of the discharge actuating devices 15 is arranged to be three in the drawing, the number is not limited to this three and 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) with respect to a predetermined movement amount of the transfer surface of the transfer conveyor 12.

Reference numeral 13 is a calibration reference reflection plate, and the calibration reference reflection plate 13 is, as shown in FIG. 3, well arranged with the light emitting / receiving port M of the coaxial reflection type measuring device sandwiching the transportation path of the transportation conveyor 12. When the articles S are arranged so as to face each other and there is no article S on the conveyance path between the two facings, the light emitted from the light source 1 via the beam splitter 5 or the like is reflected by the reflecting plate 13.
The reflected light is incident on the light projecting / receiving port M.

Reference numeral 18 denotes an article sensor, which is the conveyor 1
The detection signal is provided in a position along the transport path of the transport conveyor 12 on the upstream side of the light emitting / receiving port M with respect to the transport direction of 2, that is, upstream of the measurement position, and detects the presence or absence of fruits and vegetables S transported by the transport conveyor 12. Is output to the control unit 20.

The control unit 20 of the coaxial reflection type measuring device inputs the signal from the detecting device 11, the signal from the article sensor 18, and the signal from the encoder device 17 to obtain the quality and characteristics of the fruits and vegetables S. The discharge actuation device 1 which determines the discharge signal for sorting based on the determination result.
It is designed to output to 4. A block diagram showing an outline of the circuit of the control unit 20 will be described.

Reference numeral 21 is an input / output device (I / O), 22 is a central processing unit (CPU) for controlling the entire device, 23 is a random access memory (RAM) used as a working area, and 24 is a processing procedure of the CPU 22. A read-only memory (ROM) in which (program), set values, etc. are written in advance, 25 is a bus line to which the respective circuits are connected. The operation of the control unit 20 will be described with reference to FIG.

4 (a), (b) and (c) are time charts showing the output timings of the measurement instruction signal B and the calibration instruction signal C with respect to the detection signal A of the fruits and vegetables S by the article sensor 18. is there. That is, FIG. 4 (a) shows fruits and vegetables S
4B shows the output waveform of the detection instruction signal A, FIG. 4B shows the output waveform of the measurement instruction signal B, and FIG. 4C shows the output waveform of the calibration instruction signal C.

The control unit 20 receives the detection signal from the article sensor 18 and the signal from the encoder device 17 as I / O2.
1 to the CPU 22, and based on this input signal, the CPU 22 calculates the length (time) of the fruits and vegetables S in the conveyance direction and the length (time) of the preceding fruits and vegetables S and the fruits and vegetables S that follow. ) Is calculated to obtain the timing at which measurement and calibration are performed at a predetermined measurement position, and the signal (measurement instruction signal B, calibration instruction signal C) at the obtained timing is used to calculate I
Data (measurement data, calibration data) is obtained from an electric signal according to the amount of received light sent from the detection device 11 to / O21.

The measurement instruction signal B is output in the middle of the length of the detection signal A in the time direction as shown in FIG. 4 (b), and the calibration instruction signal C is output in the fourth direction. Figure (c)
As shown in (3), the signal is output at a predetermined position between (gap) between the previously output detection signal A and the later output detection signal A. It is preferable that the calibration instruction signal C be output immediately before the fruit or vegetables S in the subsequent row is detected. Further, as shown in the figure, when the gap is narrow, such as the gap between the detection signals A3 and A4, the calibration instruction signal C is not output. Therefore, as the calibration data in this case, the data obtained based on the calibration instruction signal C3 immediately before the detection signal A3 is used.

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

On the other hand, the reflected light taken from the fruits and vegetables S is
The detection device 11 receives the light, converts it into an electric signal according to the amount of light received, and sends it to the I / O 21 as described above.
The U22 takes in an electric signal from the I / O21 by 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, the reflectance or the reflection intensity at a specific wavelength is obtained. calculate.

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

Further, the sorting control circuit (not shown) of the control section 20 conveys the determined fruits and vegetables S to the discharge operation device 15 corresponding to the determination result of the quality and characteristics based on the determination result. At this time, a discharge command signal for operating the discharge operating device 15 is output via the I / O 21. As a result, the fruits and vegetables S transferred on the conveyor 12 can be ejected together with the tray 14 onto the carry-out conveyor 16 by operating the ejection operation device 15 at the corresponding sorting position.

FIG. 5 shows an example in which the article sensor 18 is provided on the downstream side by a predetermined distance from the light projecting / receiving port M of the coaxial reflection type measuring device in the transport direction of the transport conveyor 12. The positional relationship between the article sensor 18 and the light projecting / receiving port M of the coaxial reflection type measuring device 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 device shows a substantially central portion of the fruit or vegetable S. Is designed to measure. In this case, the encoder device 17 can be omitted.

6 (a), (b), (c), (d)
FIG. 6 is a time chart diagram showing the 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 in FIG. Note that FIG. 6A is a diagram showing the position of the fruits and vegetables S when the measurement instruction signal B is output. FIG. 6B is an output waveform of the detection signal A of the fruits and vegetables S. FIG. 6C shows an output waveform of the measurement instruction signal B. FIG. 6 (d) 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 each time the detection signal A rises. That is, the article sensor 18 outputs each time the front end of the fruit or vegetable S is detected. The calibration instruction signal C is output for a predetermined time immediately after the detection signal A is no longer output. That is, when the fruits and vegetables S pass through the article sensor 18, they are output immediately after that.

When the gap between the preceding fruits and vegetables S and the succeeding fruits and vegetables S is long, it is preferable to output the calibration instruction signal C at regular intervals. On the contrary, the detection signals A2 and A3
If the gap is narrow, such as the gap between and, the calibration instruction signal C is output, but since the interruption is canceled by the signal input of the detection signal A3, the calibration data in this case is the calibration instruction immediately before the detection signal A2. The data obtained based on the signal C2 is used.

FIG. 7 is a block diagram of an example using a bucket conveyor 30 for transferring the fruits and vegetables S one by one at regular intervals. The bucket conveyor 30 is provided with a clock signal transmitter 32 that outputs a predetermined signal for each bucket pitch and for each intermediate position between the buckets 31 and the buckets 31. That is, the clock signal transmitter 32 alternately outputs the measurement instruction signal B for each bucket 31 and the calibration instruction signal C for each intermediate interval to the control unit 20 in synchronization with the transfer of the bucket 31. . Thereby, the reflectance or the reflection intensity of the reflected light from the fruits and vegetables S can always be calculated based on the immediately preceding calibration data.

[0042]

As described above, according to the present invention, the light emitting / receiving port of the coaxial reflection type measuring device and the calibration reference reflecting plate are opposed to each other with the transport conveyor interposed therebetween, and the preceding article and the rear article transported by the transport conveyor are opposed to each other. The reflected light from the calibration reference reflector is taken in the gap between the row and the item, the calibration data is obtained from this reflected light, and this is updated and stored. Based on this updated and stored calibration data, the reflectance or reflection of the item Since the strength is calculated, calibration is performed during the transportation of the article without stopping the operation of the conveyor for calibration or interrupting the supply of the article to interrupt the measurement work of the article. Moreover, since the calibration can be performed frequently and the efficiency and measurement accuracy of the measurement work of the article can be greatly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an optical section of a coaxial reflection type measuring device.

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

FIG. 3 is an explanatory diagram showing a case where a calibration reference reflector and a light emitting / receiving port face each other with a gap in between.

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

FIG. 5 is an explanatory diagram of another example of the attachment position of the article sensor.

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

FIG. 7 is an explanatory diagram of a bucket conveyor showing another example of the transfer conveyor.

[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 absorption part 11: Detection device 12: Conveyor conveyor 13: Reference reflector for calibration 14: Saucepan 15: Discharge operation device 16: Carry-out conveyor 17: Encoder device 18: Article sensor 20: Control circuit 21: I / O 22: CPU 23: RAM 24: ROM 25: Bus line 30: Bucket Conveyor 31: Bucket 32: Clock signal transmitter S: Fruits and vegetables M: Emitter / receiver port P: Optical part A: Detection signal B: Measurement instruction signal C: Calibration instruction signal

Claims (2)

[Claims] 1. A coaxial reflection type measuring device for irradiating an article conveyed at a constant interval or an irregular interval by a conveyer, receiving the reflected light, and obtaining the reflection intensity or the reflectance based on the calibration data. A calibration method, wherein the light projecting / receiving port of the coaxial reflection type measuring device and the calibration reference reflection plate are arranged so as to face each other with the transport conveyor interposed therebetween, and the preceding article and the subsequent article transported by the transport conveyor. Calibration data is obtained from the reflected light from the calibration reference reflector and the data is updated and stored each time the calibration reference reflector and the light emitting / receiving port face each other via a gap between the calibration reference signal and the calibration instruction signal. A method for calibrating a coaxial reflection type measuring device characterized by the above. 2. A coaxial reflection type measuring device which irradiates an article conveyed at a constant interval or an irregular interval by a conveyer, receives the reflected light, and obtains a reflection intensity or a reflectance based on calibration data. There is a calibration reference reflection plate arranged to face the light emitting and receiving port of the coaxial reflection type measuring device with the transport conveyor sandwiched between the preceding article and the subsequent article transported by the transport conveyor. When the calibration reference reflection plate and the light projecting / receiving port face each other through a gap, there is provided means for obtaining calibration data from the reflected light from the calibration reference reflection plate and updating and storing the calibration data. A coaxial reflection type measuring device.