JPH0663979B2 - Crack and crack detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for detecting cracks and cracks in a test object such as grains and beans.

Technical background Grains and beans are cracked and cracked during the process of threshing, drying, and transportation, which causes the deterioration of quality. Therefore, a device that detects them is desired, but a device that operates properly has not been developed so far.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide an apparatus for appropriately detecting cracks and cracks generated in grains, beans, and the like.

Structure of the invention That is, the detection device according to the present invention, a device for detecting cracks, such as cereals, beans, cracks, an irradiation device for applying inspection light to a test object such as cereals, beans, Moving means for relatively moving the irradiation device and the object to be inspected, and arranged in front of and behind the irradiation device in the movement direction, and receives light reflected from the object to be inspected in respective predetermined angular ranges, A first and a second detector for detecting the intensity, and responding when the ratio of the intensities of the detection light detected by the first and the second detector exceeds a predetermined threshold value. The basic feature is that cracks and cracks in the specimen are detected.

Further, in addition to the basic configuration described above, the present invention provides a division circuit for calculating the ratio of the intensities of the detection lights detected by the first and second detectors, and a differentiation for differentiating the ratio calculated by the divider. And a circuit for detecting a crack or a crack in the test object in response to the differential value generated by the differentiating circuit exceeding a certain threshold value. Provide a crack detecting device.

Action and Effect of the Invention The detection device according to the present invention is configured as described above, and its principle action will be described with reference to FIGS. 1 to 4 of the accompanying drawings.

In FIG. 1, the inspection light B is directed vertically downward, the surface of the object to be inspected O makes an angle of γ with respect to the horizontal plane, and it is assumed that the surface of the object to be inspected is a perfect diffusion surface. The intensity of the reflected light R forming an angle θ (that is, the angle formed with respect to the normal line N) is proportional to the cosine of the reflection angle.

In FIG. 2, it is assumed that the object to be inspected is conveyed from right to left, and the reflected light in the range that forms an angle φ before and after the inspection light in the conveying direction of the object to be inspected is the first and the second.
When the light is received by the detectors 1 and 2 of the above, and its intensity is detected, the detection signals D1 and D detected by the detectors 1 and 2
2 becomes as follows.

However, −π / 2 + φ <γ <π / 2−φ R: reflectance I: intensity of incident rate Therefore, a bean as the test object O as shown in FIG. 3 is changed from right to left in FIG. When it is transferred to the detector, the intensity D of the reflected light from the object detected by the detectors 1 and 2 is
1 and D2 are as shown in FIGS. 4 (a) and 4 (b).

Therefore, if the ratio D3 of D1 and D2, that is, D1 / D2 is obtained, it becomes as shown in FIG. 4 (c). As can be seen from the above equation, the signal D3 is not affected by the color of the test object, that is, the difference in reflectance, and becomes a signal according to the unevenness of the inspection surface.

As can be seen from Fig. 4 (c), the value of D3 is the crack C of beans.
, And the beginning and end of the beans.

Therefore, the crack of the test object can be detected based on the signal D3. (Here, in the present invention, a means for preventing the detection device from malfunctioning as if there is a crack or a crack by the D3 at the start end and the end as described above of the test object is essential. Although it can be considered as a matter of particularity, when the object to be inspected is relatively large, the surface to be inspected may not include the above-mentioned starting end and terminating end, and therefore, as a detection device according to the present invention. However, such means is not essential.) Further, if the differential value of the signal D3 is taken, it becomes as shown in FIG. 4 (f). This differential value has a greater change than the signal D3 having the above ratio, and therefore, by using this signal, cracks and cracks in the test object can be detected more appropriately.

The above-mentioned problem of malfunction at the start end and the end of the test object can be avoided as follows.

That is, if the signals D1 and D2 from the detectors 1 and 2 are added,
A signal as shown in FIG. 4 (d) is obtained. Therefore, it is only necessary to provide a means for causing the detection device to detect cracks and cracks only when the signal becomes equal to or more than a certain level L3.

As can be seen from the above, in the detection device according to the present invention, cracks and cracks in the test object are detected based on the ratio D3 of the detection signals D1 and D2 from the detectors 1 and 2, or the differential value of the signal D3. It can be detected properly.

Embodiment Next, a detection device according to an embodiment of the present invention shown in FIGS. 5 to 7 will be described.

In FIG. 5, O is a bean as a test object. The inspection object O is conveyed from right to left in FIG. 5 by a conveyor such as a belt conveyor not shown.

The detection device 10 includes an illuminating device 12 that applies inspection light to a conveyed test object, and first and second reflected light detectors 14 arranged in front of and behind the illuminating device 12 in the transfer direction of the test object. Has 16. In this embodiment, a laser device is used as the illumination device 12, and the first and second detectors 14,
16 has condenser lenses 20, 22, 20 ', 22' and sensors 23, 23 ', respectively.

The first and second detectors 14 and 16 receive a predetermined angle range of the reflected light from the test object and send a signal proportional to the intensity to the amplifiers 24 and 26. The signal amplified by the amplifier corresponds to the above-mentioned signals D1 and D2 (Fig. 4), and is sent to the division circuit and the ratio of D1 and D, that is, D1 / D2 =
D3 is generated. The signal D3 from the division circuit is the differentiation circuit 30
To the first and second comparators 32 and 34. The first comparators 32 and 34 respectively set predetermined threshold values L1 and L2, and when the differential value signals sent to the respective comparators exceed those threshold values, the output signals are respectively output. (Fig. 4g) is sent to the OR circuit 36.

The signals D1 and D2 from the amplifiers 24 and 26 are sent to the adder 40, and the signals added by the adder are sent to the comparator 42.
A threshold value L3 is set in the comparator, and when the value from the comparator 42 exceeds the threshold value, the output signal (Fig. 4e) is output.
Send to AND circuit.

The comparator 42 and the OR circuit 36 are connected to the AND circuit 44,
When the signals from the comparator 42 and the OR circuit are input at the same time, that is, when the object is a bean, for example, the circuit is inspected in the part excluding the part near the start end and the end of the bean. A signal (FIG. 4h) is emitted when the differential value of D3 exceeds a predetermined threshold value L1 or L2 when the light is applied. Therefore, it is possible to detect that there is a crack or a crack in the test object by this signal.

FIG. 6 shows an example in which an object to be inspected is not conveyed by a belt conveyor or the like but dropped from a chute 50 for detection.

Further, FIG. 7 shows an example in which a laser emitted from a laser device as an illuminating device is used to scan an object to be inspected by a scanning mirror 60 so that the entire surface of the object to be inspected can be inspected. Is shown.

The device according to the above-described embodiment corresponds to the second invention described in the section "Structure of the Invention", but the output signal of the division circuit is changed to the first signal by removing the differentiating circuit from this device.
And the first comparator by directly inputting to the second comparators 32 and 34.
The same detection operation can be performed even with the configuration corresponding to the second invention.

[Brief description of drawings]

FIG. 1 is an explanatory view for showing the relationship between the intensity of incident light and reflected light with respect to the test object, and FIG. 2 is a view showing the relationship between reflected light and the first and second detectors. The figures show the relationship between the object to be inspected, the incident light and the detector, and FIGS. 4a to 4h show the signals D1 and D2 showing the intensity of the reflected light detected by the detector in FIG. And diagrams showing signals at each stage where these signals are processed in the device according to the present invention, FIG. 5 is a schematic diagram of the device according to one embodiment of the present invention, and FIG. 6 is a second embodiment. FIG. 7 is a diagram showing a part of the device according to the third embodiment, and FIG. 7 is a diagram showing a part of the device according to the third embodiment. 12 ... Irradiation device; 14, 16 ... First and second detectors; 28 ... Division circuit; 30 ... Differentiation circuit.

Claims (1)

[Claims] 1. A device for detecting cracks and cracks in grains, beans, etc., and an irradiation device for applying inspection light to an inspection object, such as grains, beans, etc., and the irradiation device and the inspection object. And a moving means for moving the light relative to each other in the moving direction, the first and the first being arranged in front of and behind the irradiation device to receive light reflected from the object to be inspected within a predetermined angle range and detect its intensity. Second detector, a division circuit for calculating the ratio of the intensities of the detected light detected by the first and second detectors, a differentiation circuit for differentiating the ratio calculated by the division circuit, and first and second An adder for calculating the sum of the intensities of the detection lights detected by the detectors, the differential value of the differentiating circuit exceeds a first predetermined threshold value, and the output of the adder has a second value. In response to exceeding a predetermined threshold value, cracks or cracks in the object are detected. An apparatus for detecting cracks and cracks, which is characterized by detecting cracks.