JP2923457B2 - Grain sorter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grain sorter, and more particularly, to a grain or a group of grains moving on a predetermined moving path under a predetermined image pickup means under irradiation light from a predetermined light source. Based on the density value of the captured image and a predetermined reference density value, whether or not the grain is defective,
Alternatively, the present invention relates to a grain sorter that determines whether or not a defective product is included in the grain group and sorts the grain or the grain group based on the determination result. In addition, a grain means granular grains, such as rice, wheat, and soybeans.

[0002]

2. Description of the Related Art Conventionally, it has been generally performed to perform image recognition of a grayscale image photographed by a CCD camera or the like using a reference density value (hereinafter, referred to as a threshold value) for the grayscale value. I have. There is a need for a sorting device that sorts good and bad cereals using this technique. For example, in the case of white rice, it is necessary to preliminarily sort out and remove rice grains that have been discolored to brown, black, or the like due to lack of milling or brown or black. In many grains other than white rice,
If a defective product discolored due to pain or the like is mixed in, the commercial value may be reduced.

[0003] The sorting apparatus comprises a supply unit for supplying grains,
It is composed of a photographing device for photographing a grain, a light source for photographing, a judging unit for judging whether or not the product is non-defective from photographed density information, and a sorting unit for sorting the kernel based on the judgment result. When the grains are fed into the supply unit, the light source inside the device and the imaging unit (CC
D line sensor) captures the reflection density of the grain,
The determining unit compares the shading information obtained by the photographing unit with a predetermined threshold value, and determines a non-defective product and a defective product based on the comparison result.

[0004]

Here, conventionally, when a threshold value is determined, the threshold value itself is uniform, and even if there is a change, only the entire threshold value shifts (increases or decreases). At this time, if the light amount of the light source does not change with time and is constant over the entire detection line, it is possible to sort kernels using a uniform and constant threshold value as in the conventional case.

However, a light source which does not change with time and can obtain a constant light amount over the entire detection line has problems such as complicated control, increased number of parts, and complicated maintenance. Therefore, it is unavoidable to use a light source in which the amount of light changes along the detection line or a change with time occurs.

For this reason, it is necessary to set a threshold value according to the density information that changes according to the fluctuation or change of the light source.
Note that this fluctuation is intense at the initial stage immediately after power-on, including the instability of the applied voltage. Further, even when the apparatus is continuously used for a long time, the fluctuation may occur more slowly than in the initial state.

The present invention has been made in view of the above circumstances, and has as its object to provide a grain sorter capable of coping with a change in detection level caused by a fluctuating light source or the like and capable of accurately sorting grains.

[0008]

According to the first aspect of the present invention, a grain or a group of grains moving on a moving path orthogonal to the width direction within a predetermined width dimension is received from a predetermined light source. Under the irradiation light, at least an area wider than the width dimension is instantaneously imaged by a line-shaped imaging means, and based on a density value of the imaged image and a predetermined threshold value for each pixel, Whether or not the kernel is defective, or determine whether or not the kernel group includes a defective product, kernel sorting to sort the kernel or kernel group based on the determination result Machine, when the kernels or kernels are not moving along a movement path, an image of a background surface having a predetermined reflectance is captured by the image capturing unit, and the image is captured for each pixel of the image capturing unit. Background imaging control means for measuring the density value of the read image, and The reference density value initial setting means for initial setting the reference density value for each pixel of the imaging means, and instructing the reference density value initial setting means to reset the reference density value at predetermined time intervals. Means for updating the reference density value.
Resetting the reference density value by the
From the time interval of resetting until the power is turned on and stable
Also executed at long time intervals .

According to the first aspect of the present invention, the reference density value is calculated from the density value of the captured image at predetermined time intervals. Since this reference density value is set in accordance with the variation of the light source, the reference density value is periodically changed to change the light source with time (particularly, the rise time from when the power is turned on).
Grains can be sorted out without being affected by the water.

[0010]

Here, when the power supply is stabilized, the reference density value is reset.
Perform settings from power-on to power-on stability
Run at a longer time interval than the reset time interval. this
Means the power supply voltage is unstable during the initial period after the power is turned on.
The brightness of the light source fluctuates drastically and updates frequently
Although it is necessary, after a predetermined time elapses after turning on the power,
The power supply and light source are stable, and the brightness
Roots that do not need to be updated frequently because of less
Based on As a result, basic operations performed when the power is stable
The frequency of updating semi-concentration values can be reduced,
The time spent is reduced and grain sorting can be performed efficiently.

[0012]

[0013]

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment of the First Invention) Hereinafter, an embodiment of a grain sorter according to the present invention will be described with reference to the drawings.

FIG. 1 is an external view of a grain sorter 10 according to the present invention. The grain sorter 10 is housed in a casing 11, and a grain input port 12 </ b> A of a raw material supply hopper 12 that stores grains to be sorted and supplies the grain by a predetermined amount protrudes from an upper portion of the casing 11. I have. On the side surface of the housing 11, a dial 106B for the operator to specify various parameters such as a threshold rate to be described later, a button 106C for instructing start / stop of execution of various processes, etc. Display 106A for displaying processing status etc.
There is provided an operation unit 106 having

A non-defective passage 26A through which kernels determined to be non-defective by sorting pass from the lower portion of the housing 11,
Defective product passage 26C through which kernels determined to be defective products pass
And are arranged obliquely downward, and the non-defective passage 2
A non-defective product storage box 97 is installed below the terminal end of 6A, and a defective product storage box 98 is installed below the end of the defective product passage 26C.

FIG. 2 is a schematic configuration diagram of the grain sorter 10. At the uppermost part of the grain sorter 10, there are provided a raw material supply hopper 12 and a reselection hopper 14 for storing grains to be re-sorted and supplying the grains one by one.

As shown in FIG. 3, the raw material supply hopper 12 and the reselection hopper 14 are arranged side by side in the direction of the arrow X (perpendicular to the plane of FIG. 1). Both of these lower portions are configured so that the sectional opening area becomes gradually smaller, and a grain supply port 15 having an appropriate diameter for supplying a predetermined amount of grains is provided at the lowermost portion of the raw material supply hopper 12. At the lowermost part of the re-selection hopper 14, a grain supply port 15A having an appropriate diameter for supplying grains one by one is formed. A filter 14 is provided on the upper surface of the reselection hopper 14.
A is provided, and a transport pipe 30 (see FIG. 2) for transporting grains to be re-selected is inserted into a side surface of the hopper 14 for re-selection.

As shown in FIG. 2, immediately below the grain supply port 15, a rotary valve 16 for feeding grains to a belt conveyor 18, which will be described later, by a predetermined amount at predetermined time intervals.
Is installed. As shown in FIG. 4A, the rotary valve 16 is configured to rotate around a rotation axis V in the direction of arrow Q. The rotary valve 16 has a primary sorting supply section 16A and a secondary sorting supply section 16A. A portion 16B is provided.

As shown in FIG. 4B, the primary sorting supply section 16A has a regular hexagonal cross section perpendicular to the rotation axis V, and the blade is longer than the length of one side of the regular hexagon by a predetermined length. 3
2 are fixed to each side of the regular hexagon. This allows
It is possible to store a predetermined amount of grains at a site indicated by an arrow P in FIG. 4B, and the predetermined amount of the stored grains can be stored at a predetermined timing by rotating the rotary valve 16 in the direction of the arrow Q. The grains can be supplied to the belt conveyor 18.

As shown in FIG. 4A, a total of four grain supply orbits L1 to L4 are provided at predetermined intervals along the rotation axis V in the cylindrical secondary sorting supply section 16B. 4 is set in each grain supply orbit Ln (n: 1 to 4).
As shown in (C), four holes 34 each having a size enough to accommodate one grain are formed at intervals of approximately 90 degrees. Thereby, it is possible to store one grain in each hole 34, and by rotating the rotary valve 16 in the direction of the arrow Q, the stored grains can be stored for each of the grain supply tracks at a predetermined timing. Can be supplied to the belt conveyor 18 one by one.

As shown in FIG. 2, below the rotary valve 16, a belt conveyor 18 is provided. As shown in FIG. 5, the belt conveyor 18 has rollers 38,
40 and a belt 42 wound around these rollers, and the rotation axes T1, T
2 is parallel. In addition, the belt conveyor 18
Primary sorting supply section 16 of rotary valve 16 described above
A is classified into a primary sorting transport path 18A and a secondary sorting transport path 18B corresponding to the secondary sorting supply section 16B. In the secondary sorting transport path 18B, five hard tubes 44 are arranged in the vicinity of the surface of the belt 42 at predetermined intervals in parallel with the transport direction, and transport paths R1 to R4 are formed. Each transport path Rn (n: 1 to 4) is a rotary valve 1
6 each grain supply orbit Ln of the secondary sorting supply unit 16B
(N: 1 to 4), and one grain from each grain supply orbit Ln corresponds to the corresponding transport path Rn.
It is configured to drop upward and be transported along the transport path Rn.

The hard tube 44 is supported by a supporting member 46 and a hanging member (not shown),
Even if the grain is transported along R4, the position does not shift. However, the hard tube 44 can be removed when cleaning to remove grain residue (for example, rice bran or the like) accumulated in the transport paths R1 to R4. In this manner, maintenance is facilitated for the convenience of cleaning.

The rotation speed of the belt conveyor 18 is
When the grains supplied from the primary sorting supply unit 16A of the rotary valve 16 at one time (that is, the grains stored in the portion indicated by the arrow P in FIG. 4B) drop onto the belt conveyor 18. The setting is made in accordance with the supply amount of the grain so that the particles are scattered substantially uniformly on the primary sorting conveyance path 18A.

As shown in FIG. 2, the belt conveyor 1
After being transported along the primary sorting transport path 18A or the secondary sorting transport path 18B, the grains 90 supplied to the tray 8 drop from one end of each transport path, and the falling direction ( In the lower left direction of the belt conveyor 18 in FIG.
An ejector 24 for changing the falling direction of the falling kernels and a sorting cylinder 26 in which various passages through which the sorted kernels pass are formed. Further, between the sorting cylinder 26 and the belt conveyor 18, the falling kernels are placed on the front and back 2.
A front camera 20 and a rear camera 22 for photographing from a surface are arranged.

The front camera 20 and the rear camera 22
Both are line sensor cameras having 512 pixels, and are predetermined linear regions (the photographing target regions 8 in FIG. 8 described later) wider than the width of the fall trajectory of the kernels falling from the belt conveyor 18.
4) Shoot.

As shown in FIG. 6, a center axis W1 of the visual field of the front camera 20 is substantially horizontal, and a lens 64 is provided along the axis W1. A cover 62 is provided so as to cover the field of view of the lens 64, and a slit 63 is formed at a position corresponding to an extension of the axis W1. A pair of fluorescent lamps 70 and 72 are arranged at positions symmetrical with respect to the axis W1 at the end of the slit 63.

On the other hand, the center axis W2 of the field of view of the rear camera 22 is slightly inclined downward, and the lens 68 and the cover 66 are arranged around the axis W2 in the same manner as in the front camera 20, and extend along the axis W2. Slit 67 at corresponding position
Are formed. A pair of fluorescent lamps 74 and 76 are arranged at the end of the slit 67 at positions symmetrical with respect to the axis W2.

By the way, the fluorescent lamp 70 is located on the extension of the axis W2, and the fluorescent lamp 74 is located on the extension of the axis W1, and the light from the fluorescent lamp 70 is transmitted to the rear camera 22 and the light from the fluorescent lamp 74 is transmitted. In order to prevent the light from being directly inserted into the front camera 20, colorimetric plates 78 and 80 of a predetermined color are attached to the surfaces of the fluorescent lamps 70 and 74, respectively. These colorimetric plates 78 and 80 have the same reflectance as that of white rice which is regarded as good in the selection of the present embodiment.

The grains 90 that have fallen from the belt conveyor 18 are photographed by the front camera 20 and the rear camera 22 when they reach the vicinity of the intersection F of the axes W1 and W2. At the position where the image is taken (the position corresponding to the intersection F in FIG. 6),
A reference plate 82 having a reference density (reference density) is provided in advance.

As shown in FIG. 7, the reference plate 82 is bent in an L-shape and cut out except for both ends in the direction of the arrow H. Here, the tongue pieces 82A and 82B left by the notch are arranged at positions corresponding to the intersection points F in FIG. 6 described above, and the tongue pieces 82C are fastened to the cover 66. That is, the grains fall in the space 83 between the tongue pieces 82A and 82B, and under the same conditions as the falling grains,
The reference plate 82 having the reference density is photographed.

As shown in FIG. 8, a photographing target region 84 as a region photographed by the front camera 20 which is a line sensor camera is a predetermined portion of each reference plate 82 and a space sandwiched between both reference plates 82. This is an area on a predetermined virtual line in the area 83. The space area 83 is divided into 16 areas, and each of the divided areas is provided to 16 leaf springs 48 described later and a solenoid 50 for driving the leaf springs 48 (see FIG. 10A). Correspondingly, the grain sorting operation is controlled. When viewed in the height direction, the leaf spring 48 is located slightly below the imaging target area 84. A leaf spring 48 corresponding to each of the 16 divided areas and a solenoid 5 for driving the leaf spring 48 are provided.
In order to distinguish a device group such as 0, etc., it is referred to as one channel, two channels,..., 16 channels corresponding to each region, and is referred to as a three-channel solenoid 50, for example.

As shown in FIG. 6, the front camera 20 includes an image sensor 20B including a CCD image sensor and a drive circuit 20 connected to the image sensor 20B.
A is built in, and the driving circuit 20A
0B, a video signal of the video read at 0B, a trigger signal indicating the timing of capturing the video signal, a scan start signal (hereinafter, referred to as an ST signal) indicating starting capture of a video signal (scan operation) of the capturing target area 84, and capturing. An EOS (End Of Scan) signal indicating the end of video signal capture (scan operation) of the target area 84, etc., is subjected to a first control unit 100 (see FIG. 12) for performing sorting control, which will be described later.
Send to One rear camera 22 also has an image sensor 22B
And a drive circuit 22A.
Is a second control unit 100R (see FIG.
See).

As shown in FIG. 2, non-defective passages 26A for transporting kernels determined to be non-defective and kernels determined to be reselected in the primary selection are placed in the sorting cylinder 26 described above. Re-selection passage 26B for transporting, and defective-passage 26C for transporting kernels determined to be defective in the secondary sorting
The defective product passage 26C is located at a portion corresponding to the secondary sorting conveyance route 18B of the belt conveyor 18 (ie, a portion on the near side when viewed in a direction perpendicular to the paper surface of FIG. 2).
Is formed only. As described above, a non-defective product storage box 97 (see FIG. 1) for storing grains dropped in the direction of arrow D1 in FIG. 2 is provided below the non-defective product passage 26A. Below the end of 26C, FIG.
Defective product storage boxes 98 (see FIG. 1) for storing the grains that have fallen in the direction of arrow D3 are provided.

The above-mentioned ejector 24 is installed on the upper side of the sorting cylinder 26 on the side where the grains fall. As shown in FIGS. 10A and 10B, the ejector 24 includes 16 L-shaped leaf springs 48 and solenoids 50 corresponding to the respective leaf springs 48. Each solenoid 50 is fixed to a support member 56 such that the solenoid plunger 52 is perpendicular to one surface of the leaf spring 48 corresponding to the solenoid 50, and the leaf spring 48 is also supported on the other surface. 56 (arrow J in FIG. 10B). The supporting member 56 is fastened to a predetermined mounting base member 54 (arrow K in FIG. 10B).

As shown in FIG. 9, the spatial region 83 is classified into a primary sorting falling region 86 and a secondary sorting falling region 88, in which a large number of grains 90 fall at one time. On the other hand, in the falling area 88, one grain 90 at a time
Falls. On the other hand, the above-described front camera 20 and rear camera 22 photograph the photographing target region 84 (dotted line portion) at predetermined time intervals. Therefore, when the grain 90 falls in the space area 83 and passes through the shooting target area 84, the grain is shot by the front camera 20 and the rear camera 22.

By the way, rice which is regarded as defective (hereinafter referred to as rice)
(Referred to simply as defective) is darker and has a higher density and lower light reflectance than normal white rice, so that an image of such a defective product is dark and the video signal level of the image is It is lower than the level of the video signal of the captured image.

The front camera 20 and the rear camera 2
The background of the photographing target area 84 photographed by 2 is colorimetric plates 78 and 80 attached to the fluorescent lamps 70 and 74. Since the reflectance of the colorimetric plates 78 and 80 is substantially the same as that of normal white rice, the level of the video signal of the image of the white rice is substantially the same as the level of the video signal of the image of the background, and the defective product is defective. Only the level of the video signal of the image in which the image is captured is reduced.

Therefore, the threshold value is determined based on the level of the video signal of the image of the background, and in the primary sorting, the kernel group 90D is determined depending on whether the signal level is lower than the threshold value. Is determined whether or not the defective 90C contains defective products 90C.
It is determined whether it is B or normal white rice 90A.

Although the details will be described later, when it is determined that the video signal level of the image obtained by capturing the kernel 90 is lower than the predetermined level, or when the video signal level of the image obtained by capturing the kernel group 90D becomes the predetermined level If it is determined to be lower than this, a voltage of about 36 volts is instantaneously applied to the solenoid 50 of the channel corresponding to the area where these images were taken. By this application, the solenoid plunger 52
However, the leaf spring 48 corresponding to the solenoid 50 is instantaneously hit, and the falling grain 90 or the group of grains is repelled by the leaf spring 48 in the direction of arrow M in FIG. Thereby, the grain 90 or the grain group is re-selected in the sorting cylinder 26 through the reselection passage 2.
6B or the defective product passage 26C.

As shown in FIG. 2, below the end of the reselection passage 26B, the kernels dropped in the direction of arrow D2 are collected, and the collected kernels are subjected to the secondary hopper 14 for secondary sorting. An injector 28 is provided for sending the fuel to the air. The injector 28 has a funnel-shaped receiving portion 28B for collecting the kernel dropped in the direction of arrow D2 and a pair of spray nozzles 2 for blowing high-pressure air to the collected kernel.
8A (only one is shown in FIG. 2), and a transport unit 28C for transporting kernels. A high-pressure blower 58 shown in FIG. 11 is provided at one end of the blowing nozzle 28A indicated by the arrow C1, and the blowing nozzle 28A is connected to each of a pair of discharge ports 60 from which high-pressure air is discharged. .

The outlet on the side where air is discharged from the blowing nozzle 28A and the intermediate part (arrow C2 portion) in the conveying section 28C are formed so that the cross-sectional area of the cross section perpendicular to the direction of air flow is reduced. ing.

One end of the above-described transport pipe 30 is connected to the transport section 28C, and the grains reach the reselection hopper 14 through the transport pipe 30 by the injector 28.

Next, the configuration of the first control unit 100 will be described with reference to FIG. The first control unit 100 includes a video signal input terminal 116 for inputting a video signal, a trigger signal, an ST signal, and an EOS signal from the drive circuit 20A built in the front camera 20, a trigger signal input terminal 118, a start signal Signal input terminal 128, EOS
A signal input terminal 130 is provided.

The video signal input terminal 116 and the trigger signal input terminal 118 are connected to the sample and hold circuits 108 and 110, of which the trigger signal input terminal 118 is also connected to the counter 122.

The counter 122 has a trigger signal input terminal 1
Each time a trigger signal indicating the timing of capturing the video signal of each pixel transmitted from the pixel 18 is received, the count value N is counted up one by one, and the count value N is transmitted to the extraction timing circuit 114. Extraction timing circuit 1
14 is the count value N from the counter 122 and the CPU 10
The switch 112 is turned on when the pixel number M is compared with the pixel number M required from Step 2. At this timing, the sample hold circuit 108 sends a video signal of an image captured by the pixel of the pixel number M to the CPU 102.

In this way, the CPU 102
A video signal of an image captured by each of the pixels is sequentially received.

In the received video signal, the CPU 102 sets a rising portion (arrow Z1 in FIG. 14A) and a falling portion (arrow Z in FIG. 14A) of the signal level.
2), the start point S1 and the end point S2 of the space area 83 are detected, and the start point S1 and the end point S2 are detected.
The space region 83 sandwiched between the divided regions is divided into 16, and a predetermined number (for example, 20 bits) of pixels are allocated to each divided region (that is, each channel). Then, information on pixel assignment to each channel is stored in an S-RAM (Static RAM) 134.

In a threshold setting process described later, the CPU 102 calculates threshold data for each pixel based on the received video signal, and stores the threshold data for each pixel in the S-RAM 124. In addition, in order to cope with a temporal variation of the light source, the CPU 102 executes the processing shown in FIG.
The threshold is periodically updated according to the flowchart of FIG. That is, since the light amount of the light source is unstable for about 30 minutes from the start of the operation, the threshold value is updated every 5 minutes accordingly. Further, even after the stabilization, the light amount may fluctuate due to the environmental temperature and humidity. In this embodiment,
The threshold value is updated every 30 minutes. At the time of updating the threshold, the sorting of the grains is temporarily stopped. However, since the updating of the threshold is indispensable for accurately determining the grains, it takes precedence over work efficiency. I try to make it.

At the time of grain sorting, the threshold data read from the S-RAM 124 is converted into a D / A signal by a D / A converter.
The converted analog threshold data and the video signal from the video signal input terminal 116 are compared by the comparator 120.

When the level of the video signal from the predetermined pixel is lower than the level of the analog threshold data, the comparator 120 converts the predetermined detection signal to the multiplexer 13.
6 and the multiplexer 136 outputs the S-RAM 13
4, the output terminal 1 of the channel corresponding to the predetermined pixel based on the assignment information of the pixel to each channel stored in
The detection signal is output to 37.

The start signal input terminal 128, EO
Based on the operation of the reset circuit 132 based on the signal from the S signal input terminal 130, the count value of the counter 122 is reset after one scan.

Further, the CPU 102 has a display 106 of the operation unit 106 via the I / O controller 104.
A, a button 106C and a dial 106B are connected. For example, parameter information such as a threshold rate designated by an operator through the dial 106B is stored in the CPU 102.
Sent to

On the other hand, the configuration of the second control unit 100R for controlling the rear camera 22 is the same as the configuration of the first control unit 100. Note that the operation unit 106 is provided by the first control unit 10.
0, shared by the second control unit 100R, and also connected to the second control unit 100R. That is, by operating the operation unit 106, the operator can instruct the first control unit 100 or the second control unit 100R, or both, to specify various processes and specify parameters and the like.

As shown in FIG. 13, the output terminal 137 from the first control unit 100 provided for each channel and the second
The output terminal 146 from the control unit 100R is connected to the solenoid 5
It is connected to a solenoid drive unit 144 for driving the zero. The solenoid driving unit 144 includes a solenoid driving circuit 138 that performs a logical OR operation and sends a timing signal for driving the solenoid, a photocoupler 140 for insulation,
And a triple voltage boosting circuit 142 for amplifying the voltage of 2 volts three times when the solenoid is driven. The solenoid driving circuit 138, the photocoupler 140, and the triple voltage boosting circuit 142 are provided for each channel. . An output terminal 137 and an output terminal 146 of each channel are connected to a solenoid drive circuit 138 for the channel, and a solenoid drive circuit 138, a photocoupler 140, a triple voltage multiplier 142, and a solenoid 50 provided for each channel are provided. Are connected in order.

As shown in FIG. 18A, the triple voltage multiplier 142 includes a capacitor 148 set so that a voltage of 36 volts can be applied. In the triple voltage multiplier 142, when the photocoupler 140 is turned on, a current flows in the direction of the arrow U1, and the transistor 154 is turned on. As a result, the circuit between the terminal 156 and the ground 158 is closed, and the electric current accumulated in the capacitor 148 causes a current to flow in the direction of the arrow U2.
It is configured to apply a voltage of volt.

By setting the capacitors 150 and 152, the voltage applied to the solenoid 50 as described above is about 20 milliseconds as shown in the time-voltage characteristic shown in FIG. It is configured to step down to 12 volts. With such a configuration, it is possible to prevent the solenoid 50 from being deteriorated or damaged due to the high voltage (36 volts) being applied to the solenoid 50 for a long time.

Next, the operation of the present embodiment will be described. In order to perform grain sorting in the grain sorter 10, a teaching process for initial setting is performed at an initial introduction of the grain sorter 10 or at predetermined time intervals.

Hereinafter, the teaching process will be described. When the operator instructs the start of the teaching process by operating a predetermined button or automatically at a predetermined time, first, the front camera 20 and the rear camera 22 shoot the shooting target area 84, and the video signal of the shot image is driven. The signals are sent to the first control unit 100 and the second control unit 100R via the circuits 20A and 22A, respectively.
In addition to the video signal, an ST signal is input from the drive circuits 20A and 22A to the start signal input terminal 128 at the start of one scan of the imaging target area 84.
At the end of each scan, the EOS signal is input to the EOS signal input terminal 130, and the trigger signal is input to the trigger signal input terminal 118 at the timing at which the video signal is to be captured by each control unit.
To each other.

In each of the control units receiving these signals, a teaching process shown in FIG. 16 is executed. Hereinafter, the first
The teaching process in the control unit 100 will be described as an example.

When the scanning of the photographing target area 84 is started and the ST signal is received via the start signal input terminal 128, the count value N of the counter 122 is reset. Thereafter, as the scanning progresses, the video signal is continuously input to the video signal input terminal 116 and is held in the sample and hold circuit 108.

Then, when the timing to capture the video signal comes and the trigger signal is received via the trigger signal input terminal 118, the count value N of the counter 122 is incremented by 1 and the count value N becomes "1". .

On the other hand, the CPU 102 executes step 2 in FIG.
At 00, a request signal for capturing the video signal of the first pixel from the start is extracted as an extraction timing signal 11.
4 In the extraction timing signal 114, C
Pixel number M requested by PU 102 and counter 122
And the switch 112 is turned on when they match.

When the switch 112 is turned on, the video signal held in the sample and hold
02. Thus, the CPU 102
The video signal of the first pixel in the scan can be captured.

Thereafter, the video signals of the second and subsequent pixels are also captured by the CPU 102 in the same procedure as described above, and finally the video signals of all 512 pixels are captured by the CPU 102.

The position in the photographing target area 84 photographed by each pixel and the signal level of the video signal fetched as described above have characteristics as shown in the diagram of FIG. In the diagram of FIG. 14A, the arrow Z1 portion where the signal level fluctuates rapidly corresponds to the boundary S1 between the reference plate 82 and the space area 83 in FIG. This corresponds to the boundary portion S2 in FIG.

Therefore, in step 202 of FIG. 16, by specifying the arrows Z1 and Z2 in the diagram of FIG. 14A based on the signal level, the boundaries S1 and S2 are specified. Spacing, ie, spatial region 83
(Hereinafter, referred to as an actual detection width L) is measured.

In the next step 204, the actual detection width L is set to 1
A predetermined number (for example, 20) of pixels is allocated to each of the divided regions, that is, each channel. In the grain sorting process described below, the solenoid 5 is used for each channel.
Control such as driving of 0 is performed. Further, in the next step 206, the result of pixel assignment to each of the 16 channels in total is stored in the S-RAM 134.

By the way, as is apparent from the diagram of FIG. 14A, the boundary portion S1 indicating the density of the background (ie, the density of the image obtained by photographing the colorimetric plates 78 and 80 having the same reflectance as the white rice).
Between S2 and S2, the density should be uniform.
The signal level varies due to the shading of ~ 76.

Therefore, in the next step 208, the maximum value _Lmax is specified from the signal level of the fetched video signal (vertical axis in the diagram of FIG. 14A). In the next step 210, to the maximum value L _max of the signal level of the video signal, the alpha (shading coefficient indicating a degree of i.e. shading) ratio of the detected signal level at each pixel is calculated for each pixel.

[0071] In the next step 212, it calculates a comparison ratio β of the maximum value L _max for detecting the signal level L _ST of the reference plate 82. Since the reference plate 82 is arranged at a position equivalent to the photographing position of the falling kernel, it is photographed under the same optical conditions as the falling kernel. Therefore, the comparison ratio β is
The one that is always constant in one grain sorter 10, and when the grain sorter 10 performs the grain sort processing later, the comparison ratio β does not change even if an error or variation occurs in the fluorescent lamp or each camera. Can be considered.

In the next step 214, the calculated shading coefficient α, comparison ratio β, maximum signal level L _max , and detection signal level L _ST of the reference plate 82 are calculated by SR.
Store it in AM124.

The above teaching process is performed by the first controller 1
Similarly to the case of 00, the second control unit 100R is also executed based on the video signal from the rear camera 22 and the like.

Next, the processing for sorting the grains will be described. In the process of selecting the kernel, a threshold setting process for setting a threshold value for each pixel serving as a reference for the kernel selection, and a kernel is selected based on the set threshold value Cereal sorting process.

Hereinafter, these processes will be described in order. After the operator specifies a desired threshold rate with the dial 105 and then instructs the start of threshold setting processing by button operation, the threshold setting processing starts to be executed.

In the threshold setting process, first, similarly to the above-described teaching process, the front camera 20 and the rear camera 22 photograph the photographing target area 84, and the video signal of the photographed image is transmitted through the driving circuits 20A and 22A. These are sent to the first control unit 100 and the second control unit 100R, respectively.

In the first control unit 100 and the second control unit 100R, the video signal is transmitted to the CPU 102 at an appropriate fetch timing based on the trigger signal, as in the teaching process.
Is taken into.

Then, the CPU 102 starts execution of the control routine of the threshold value setting process shown in FIG. First, in step 232, the detection signal level L _ST ′ of the reference plate 82 is measured based on the fetched video signal.

In the next step 234, the current reference plate 8
And second detection signal level L _ST ', and a comparison ratio β of the signal level maximum value L _max for detecting the signal level L _ST of the reference plate 82 obtained by the teaching processing, the correction value of the signal level maximum value L _max L _max ^′ , that is, a correction value L _max ^′ that corrects for the error and variation of the fluorescent lamp and each camera and the influence of the voltage fluctuation of the light source.

In the next step 236, the calculated correction value L _max ^′ is multiplied by the shading coefficient α for each pixel obtained in the teaching process. Thereby, a characteristic curve 172 of FIG. 14B is obtained. Furthermore, the result of this multiplication is multiplied by the threshold factor γ specified by the operator, the threshold L _TH (Fig. 14 corrected threshold L _TH, i.e. the effect caused by the shading of each pixel ( Characteristic curve 17 of B)
4) is calculated and stored in the S-RAM 124.

As described above, the threshold value L _TH for each pixel corrected for the influence due to the error / variation of the fluorescent lamp or each camera and the voltage fluctuation of the light source and the influence due to the shading is set. The value setting processing ends.

The threshold rate γ for setting the threshold L _TH is almost the same every time, and the error and variation of the fluorescent lamp and each camera and the influence of the voltage variation of the light source are within an allowable range. In some cases, the threshold value setting process may be performed at the same time as the teaching process, and the threshold value L _TH for each pixel may be calculated and stored.

When the shading variation is large, it is desirable to calculate the shading coefficient α for each pixel periodically and frequently, and to update the previous shading coefficient α stored in the S-RAM 124 each time. . In particular, during a short period immediately after the power is turned on, the light source greatly fluctuates, and the shading varies greatly. Therefore, it is necessary to update the shading coefficient α at relatively short intervals.
For example, the shading coefficient α is updated at a relatively short interval for a predetermined time after the power is turned on. After that, since the light source is stabilized and the fluctuation is reduced, the interval is extended and updated.
The time during which sorting is paused for the update process is reduced,
Sorting is performed efficiently. Each interval can be changed according to the characteristics of the light source. In the present embodiment, 5 minutes for 30 minutes after the power is turned on.
Teaching processing is performed at minute intervals, and thereafter correction is performed at 30 minute intervals.

This processing is shown in the flowchart of FIG. When the power is turned on, the process is started, and it is checked in step 250 whether the period during which the power is off is 5 minutes or less. If the power-off period is 5 minutes or longer, it is determined that the grain sorter 10 has been cold-started, and the routine proceeds to step 252, where teaching processing is performed. Subsequently, in step 254, it is checked whether 30 minutes have elapsed since the power was turned on. If it is less than 30 minutes after the power is turned on, the determination is negative, and the routine goes to step 256. In step 256, the process waits until 5 minutes have passed since the previous teaching. If five minutes have elapsed, the process returns to step 252, and the teaching process is performed every five minutes.

If the determination in step 254 is affirmative, that is, if 30 minutes have elapsed since the power was turned on, it is determined that the light source has become stable, and the flow proceeds to step 258. Step 250
If the determination is affirmative, that is, if the power is turned on again within 5 minutes after the power is turned off, it is determined that the light source has already been stabilized (hot start), and the routine proceeds to step 258. In step 258, the process waits until 30 minutes have elapsed since the previous teaching. Thereafter, the process proceeds to step 260, where the teaching process is performed, and the process again proceeds to step 258. Therefore, during the stable period of the light source, the teaching process is performed every 30 minutes.

Next, the grain sorting process will be described. First, grains to be sorted are loaded into the raw material supply hopper 12 by an operator or a predetermined grain loading machine. The introduced grains fall from the grain supply port 15 and rotate.
Between the blades 32 of the primary sorting supply section 16A (FIG. 4B).
(Arrow P).

On the other hand, the rotary valve 16 is rotating at a predetermined angular velocity in the direction of arrow Q. When the rotary valve 16 rotates by a predetermined angle or more from the position shown in FIG. Is supplied to the primary sorting conveyance path 18A. At this time, since the rotation angular speed of the rotary valve 16 and the transport speed of the belt conveyor 18 are appropriately set in advance, the grains are scattered substantially uniformly.

The grains supplied to the primary sorting conveyance path 18A fall from one end side of the belt conveyor 18 after a predetermined time, and during the fall, the grain corresponding to the position indicated by the arrow F in FIG. When passing through the target area 84, images are taken by the front camera 20 and the rear camera 22.

Here, the following primary sorting process is performed on the grains 90 falling from the primary sorting transport path 18A. A video signal for an image including the grain 90 captured by the front camera 20 and the rear camera 22 is sent to the first control unit 100 and the second control unit 100R via the drive circuits 20A and 22A, respectively.

The operation of the first controller 100 and the second controller 10
Since the operation of the first control unit 10R is the same as that of the first control unit 10R,
The process at 0 will be described as an example. Grain 9 photographed
A video signal for an image including 0 is input to the sample and hold circuit 110 via the video signal input terminal 116 and is temporarily held. The trigger signal from the drive circuit 20A is sent to the sample and hold circuit 110 and the counter 122 via the trigger signal input terminal 118. Note that the count value N of the counter 122 is initially reset by the operation of the reset circuit 132 that has received the ST signal from the drive circuit 20A.

When the trigger signal is received by the counter 122, the count value N is incremented by an increment “1”, and a signal indicating the count value N is sent to the S-RAM 124. Then, after the threshold data regarding the pixel corresponding to the count value N is D / A converted by the D / A converter 126 from the S-RAM 124, the comparator 12
Sent to 0.

On the other hand, when the trigger signal is received by the sample and hold circuit 110, the sample and hold circuit 11
0 sends the held video signal to the comparator 120.

As a result, the analog threshold data for the pixel corresponding to the count value N and the video signal detected at the pixel are sent to the comparator 120 in synchronization. Here, the comparator 120 performs a comparison operation between the received video signal and analog threshold data. Here, for example, in the signal level characteristics shown in FIG. 15, when the signal level of the video signal is lower than the threshold value 174 as indicated by arrows G1 and G2, a predetermined detection signal is transmitted to the multiplexer 136. I do. If the signal level of the video signal is higher, the detection signal is not sent.

On the other hand, the S-RAM 134 stores the SR
The same signal as the signal indicating the count value N transmitted to the AM 124 is transmitted, and the channel information to which the pixel corresponding to the count value N belongs is transmitted to the multiplexer 136.

The multiplexer 136 outputs the SR signal only when a predetermined detection signal is received from the comparator 120.
Based on the channel information from the AM 134, the detection signal is sent to an output terminal 137 corresponding to the channel.

As described above, defective pixels can be detected by detecting pixels whose video signal level is lower than the set threshold value based on the video signal of the image captured by the front camera 20. . Further, a channel to which the pixel belongs, that is, a channel corresponding to a region where a defective product falls can be specified.

[0097] Also in the second control unit 100R, the channel corresponding to the area where the defective product falls can be specified in the same manner as described above. Also, the count value N
Is described as “1”, but the counter 12
2 increments the count value N each time the trigger signal is received, and thereafter, the above-described processing is sequentially performed on the video signal of the pixel corresponding to the incremented count value N.

Next, the solenoid driving unit 1 which receives the detection signals from the first control unit 100 and the second control unit 100R
The operation at 44 will be described.

A solenoid drive circuit 138 provided for each channel shown in FIG. 13 responds to the reception signals at the output terminals 137 and 146 of the corresponding channel.
OR operation is being performed. Therefore, if it is determined that at least one of the first control unit 100 and the second control unit 100R, the kernel group including defective products has passed through the area corresponding to the channel, the solenoid driving circuit 138 determines
"1" is set by the OR operation, and a timing signal for driving the solenoid is transmitted.

When this timing signal is transmitted,
8A, the photocoupler 140 is turned on, a current flows in the direction of the arrow U1, and the transistor 154 is turned on. As a result, the circuit between the terminal 156 and the ground 158 is closed, the electric current accumulated in the capacitor 148 causes a current to flow in the direction of the arrow U2, and a voltage of 36 volts is instantaneously applied to the solenoid 50 (see FIG. B)).

As a result, the solenoid plunger 52 of the channel determined to have passed the grain group containing the defective product pops out, and the leaf spring 48 of the channel is flipped in the direction of arrow M in FIG. 10B. Here, the spring 48
Repels a group of grains falling in a region corresponding to the same channel.
Falling to 6B.

On the other hand, the first control unit 100 and the second control unit 10
In any of the 0Rs, if no pixel having a video signal level lower than the threshold value is detected, it can be determined that no falling product is included in the falling kernel group, and the solenoid drive is performed. No detection signal is sent to the portion 144, and the leaf spring 48 is not repelled as described above. Therefore, the falling kernels are not repelled by the leaf spring 48, but fall into the non-defective product passage 26 A of the sorting cylinder 26 and are stored in the non-defective product storage box 97.

Next, a description will be given of a secondary sorting process for a grain determined to be re-selected by the above-described primary sorting process (hereinafter, referred to as a re-selection target grain).

The reselection target grains which have been repelled by the leaf springs 48 and fallen in the reselection passage 26B are received by the receiving portion 28 of the injector 28.
Store in B. At the lower part of the receiving part 28B, a high pressure blow 58
Is blown through the discharge port 60 and the spray nozzle 28A.

Accordingly, the reselection target grains stored in the lower part of the receiving portion 28B are blown off in the direction of arrow F1 by the high-pressure air, and are conveyed to the reselection hopper 14 via the conveying portion 28C and the conveying pipe 30. Since the tip of the spray nozzle 28A and the central part of the conveying part 28C are formed so as to have a small cross-sectional opening area, the moving speed of the air passing through this part is amplified and the re-election target grain is increased. The ability to transport the grains is enhanced.

The re-selection target grains transported to the re-selection hopper 14 are supplied to the secondary selection supply section 16B of the rotary valve 16.
Drops one by one from the grain supply port 15A corresponding to each row and enters the hole 34 of the secondary sorting supply section 16B.

On the other hand, the rotary valve 16 is rotating in the direction of arrow Q at a predetermined angular velocity, and when the rotary valve 16 rotates by a predetermined angle or more from the position shown in FIG.
The re-selection target grains that have entered are supplied to the corresponding transport paths Rn (n: 1 to 4) of the secondary sorting transport path 18B of the belt conveyor 18.

[0108] After a predetermined time, the reselection target grains supplied to the secondary sorting conveyance path 18B fall from one end side of the belt conveyer 18, and during the fall, the shooting target area 84
When passing through the front camera 20, the rear camera 22
Will be taken by

Here, a second sorting process is performed on the re-selection target grains falling from the secondary sorting transport path 18B. In the secondary sorting process, substantially the same process as the above-described primary sorting process is performed, except that the target is a single reselection target grain or a group of grains.

That is, the first controller 100 sets the video signal higher than the set threshold value on the basis of the video signal of the image of the reselection target grain when passing through the shooting target area 84 shot by the front camera 20. It is determined whether or not the signal level is low, and when the video signal level is lower than the threshold value, that is, when the re-election target kernel is defective, the channel corresponding to the fall trajectory of the re-election target kernel is determined. Output terminal 13
7, a predetermined detection signal is transmitted. Also, the second control unit 10
In the case of 0R, the same process is performed based on the video signal of the image of the re-selection target grain when passing through the shooting target area 84 shot by the rear camera 22.

In the solenoid driving section 144, the first control section 100 or the second control section 10
When a detection signal is received from at least one of ORs,
A solenoid drive timing signal is sent from the solenoid drive circuit 138, and a voltage of 36 volts is instantaneously applied to the solenoid 50 corresponding to the channel.

As a result, the solenoid plunger 52 of the channel corresponding to the fall trajectory of the reselection target grain determined to be defective is popped out, and the leaf spring 48 is moved to the position shown in FIG.
In the direction of arrow M. The leaf spring 48 that has been flipped
The re-selection target grain determined to be defective is repelled, and the re-selection target grain falls into the defective product passage 26C of the sorting cylinder 26 and is stored in the defective product storage box 98.

On the other hand, the first control unit 100 and the second control unit 10
If no detection signal is received from any of the 0Rs, the re-election target kernel is determined to be good, and the leaf spring 48
It is not repelled, but falls into the non-defective product passage 26A of the sorting cylinder 26 and is stored in the non-defective product storage box 97.

According to the above-described embodiment, in the threshold value setting processing, the threshold value L _TH corrected for the error / variation of the fluorescent lamp and each camera, the influence of the voltage fluctuation of the light source, and the influence of the shading. Is set for each pixel, so that the kernel sorting process can be performed with extremely high accuracy. Further, by performing the correction of the threshold value _LTH periodically, an optimum threshold value is always set even when the brightness of the light source changes with time. Particularly, immediately after the start of the operation, the teaching process is performed at a relatively short interval during a period in which the brightness of the light source is unstable, so that an optimum threshold value can always be obtained. When the above-mentioned period has elapsed, the grains can be sorted efficiently by increasing the interval of the teaching process.

In the grain sorting process of this embodiment, a primary sorting process for sorting a group of grains containing defective products, and a secondary sorting process for sorting grains determined to be defective products one by one. In the case where there are a large number of grains to be sorted, in order to improve the processing efficiency of the sorting process, the process of sorting a group of grains containing defective products is performed in a plurality of stages. It may be a total of three or more steps.

In this embodiment, the threshold value for grain selection is set for each pixel. However, the threshold value may be set for each channel and grain selection processing may be performed.

In the present embodiment, the value of each period and time for performing the teaching process periodically may be changed in accordance with the characteristics of the light source.

In this embodiment, the threshold value is updated periodically. However, the update method described below may be used. A sample pixel (for example, one for every 10 pixels) is determined in advance from the pixels of one line, and the light amount (density value) of this pixel is recorded. The sorting operation is periodically stopped, and the degree of coincidence between the previously recorded density value and the amount of light of the same pixel obtained this time is determined. If the degree of coincidence is equal to or more than a predetermined percentage (for example, 80%), Continue to use the previous threshold without updating the threshold. Work efficiency can be improved while maintaining accurate sorting.

[0119]

As described above, in the grain sorter according to the first aspect of the present invention, an appropriate threshold value is automatically set even under illumination where the brightness varies with time and the position on the detection line fluctuates. This setting has the effect that image recognition is performed reliably.

The grain sorter according to the second aspect of the present invention comprises:
By updating the threshold value at a relatively short interval during a predetermined period immediately after power-on, in which the brightness of the light source is unstable, it is possible to always use the optimum threshold value.

The grain sorter according to the third aspect of the present invention comprises:
By updating the threshold value at a relatively long interval when the brightness of the light source becomes stable after a predetermined time has elapsed since the power was turned on, an optimum threshold value is used, and the threshold value is updated. This has the effect of saving time.

[Brief description of the drawings]

FIG. 1 is an external view of a grain sorter of the present embodiment.

FIG. 2 is a schematic configuration diagram of a grain sorter.

FIG. 3 is a perspective view of a raw material supply hopper and a reselection hopper.

FIG. 4A is a perspective view of a rotary valve,
(B) is a cross-sectional view of a primary sorting supply unit of the rotary valve, and (C) is a cross-sectional view of a secondary selection supply unit.

FIG. 5 is a perspective view of a belt conveyor.

FIG. 6 is a diagram illustrating an arrangement of a camera, a fluorescent lamp, a reference plate, a belt conveyor, and the like.

FIG. 7 is a perspective view of a reference plate.

FIG. 8 is a diagram showing the vicinity of a region to be photographed by a camera.

FIG. 9 is a diagram when a grain falls into a region to be photographed by a camera.

FIG. 10A is a perspective view of an ejector, and FIG.
FIG. 2 is a sectional view of an ejector.

FIG. 11 is a schematic diagram of a high pressure blow.

FIG. 12 is a diagram illustrating a circuit configuration of a first control unit.

FIG. 13 is a schematic configuration diagram of a solenoid driving unit.

14A is a diagram illustrating signal level characteristics in a teaching process, and FIG. 14B is a diagram illustrating signal level characteristics in a threshold setting process.

FIG. 15 is a diagram illustrating an example of a signal level characteristic in a kernel sorting process.

FIG. 16 is a flowchart showing a control routine of a teaching process executed by CPUs of the first and second control units.

FIG. 17 is a flowchart showing a control routine of a threshold setting process executed by CPUs of the first and second control units.

FIG. 18A is a circuit diagram of a triple voltage booster circuit, and FIG.
FIG. 3 is a diagram showing a relationship between applied voltage and time when a solenoid is driven.

FIG. 19 is a flowchart showing a control routine executed by the CPUs of the first and second control units and periodically instructing a teaching process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Grain sorter 20 Front camera (imaging means) 22 Rear camera (imaging means) 70, 72, 74, 76 Fluorescent lamp (light source) 78, 80 Colorimetric plate (background surface) 82 Reference plate (reference member) 90 Kernel 102 CPU

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-323999 (JP, A) JP-A-58-131181 (JP, A) JP-A-59-117698 (JP, A) JP-A-5-131 146764 (JP, A) JP-A-58-81473 (JP, A) JP-A-2-83436 (JP, A) JP-A-61-210929 (JP, A) (58) Fields investigated (Int. ⁶ , DB name) G01N 21/00-21/90

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein a grain or a group of grains moving along a movement path orthogonal to the width direction within a predetermined width dimension is at least wider than the width dimension under irradiation light from a predetermined light source. An image is taken by a line-shaped imaging unit that instantaneously takes an image of a region, and based on a density value of the taken image and a predetermined threshold value for each pixel, whether or not the grain is defective, or A grain sorter that determines whether a defective product is included in the grain group, and sorts the grain or the grain group based on the determination result, wherein the grain or the grain group is A background surface imaging control unit for imaging a background surface having a predetermined reflectance by the imaging unit when not moving along the movement path, and measuring a density value of the imaged image for each pixel of the imaging unit; And the reference density for each pixel of the imaging means based on the measured density pattern. A reference density value initialization means for performing an initial setting value, relative to the reference density value initial setting means, and the reference density value updating means for instructing re-setting of the reference density values at predetermined time intervals,
When the power supply is stable, the reference density value update changing means
The resetting of the reference concentration value should be performed after the power is turned on.
A grain sorter that is executed at a longer time interval than before reaching a predetermined time .