Granular material splashing detection device and granular material sorting device provided with the same

Abstract

Provided are: a conveying unit that conveys granular material; a photographing unit that can photograph the granular material conveyed by the conveying unit; and a splashing determination unit that can determine whether or not the granular material conveyed by the conveying unit has splashed based on data obtained by the photographing unit.

Description

Technical Field

[0001] The present invention relates to a particulate splash detection device capable of detecting splashes of flowing particulate matter, and a particulate sorting device equipped with the splash detection device. Background Technology

[0002] Previously, optical particle sorting devices could sort various granular materials, such as grains. However, the flow pattern on the conveyor chute varies depending on the type, shape, size, and flow rate of the particles. When particles flow down the chute under these conditions, they splash (bouncing) as they fall. Because of this splashing and bouncing, the particles cannot follow a normal flow path when discharged from the bottom of the chute, making accurate sorting impossible. This deviation from a normal flow path is sometimes a major cause of reduced sorting accuracy in particle sorting devices.

[0003] In optical particle sorting devices, various technical means have been used in the past to suppress the "splashing" of the aforementioned particles.

[0004] Patent Document 1 discloses a granular material sorting device that can suppress "splashing" on the chute even when soybeans, which are not truly spherical, are used as the sorting material. This granular material sorting device employs the following technique: multiple air nozzles are provided on the bottom surface of the chute through which the granular material flows. Furthermore, an air storage chamber is provided on the back side of the bottom surface of the chute to spray air from these nozzles, and a blower is connected to this air storage chamber. That is, the sorting material flowing down the chute is slightly lifted and flows down due to the air spray from the nozzles. As a result, the sorting material is arranged in a flow state that does not contact the bottom surface of the inclined chute and thus does not splash, and the flow trajectory of the sorting material in the detection section is made uniform.

[0005] However, the invention described in Patent Document 1 requires a large structure with multiple air jets on the bottom surface of the chute and an air storage chamber on the back side of the bottom surface of the chute, connecting the blower to the air storage chamber. Furthermore, it is difficult to adapt to the various types, shapes, sizes, and flow rates of granular materials such as grains.

[0006] Patent Document 2 describes an invention of a granular material sorting device for sorting soybeans that are not truly spherical. A gate for adjusting the amount of soybeans supplied to the inclined flow path is provided at the upper end of the inclined flow path. Furthermore, a vibrating supply path and an inclined flow path are arranged linearly downstream to suppress "splashing" of soybeans flowing down the inclined flow path.

[0007] However, the invention described in Patent Document 2, like the invention described in Patent Document 1, is difficult to adapt to the various types, shapes, sizes, and flow rates of granular materials such as grains.

[0008] Patent documents 3 and 4 disclose inventions for sorting long-grained granules such as rice and granules with sticky surfaces such as parboiled rice. A chute for an optical sorting machine is disclosed that, even when a large quantity of such sorting materials is supplied, it can suppress uneven flow of the granules and prevent the granules from splashing on the chute and dispersing downwards.

[0009] Specifically, Patent Document 3 discloses a structure in which a chute comprises a first part and a second part. The first part has a surface forming multiple protrusions and receives the sorted material from a vibrating feeder. The second part is continuous with the first part, allowing the sorted material to fall freely from its lower end. Thus, the first part, which receives the sorted material supplied from the vibrating feeder, has a surface forming multiple protrusions, thereby reliably dispersing the sorted material falling onto the first part and preventing uneven flow of granular material. As a result, it is described to prevent detection errors of defective products and improve sorting accuracy.

[0010] Furthermore, Patent Document 4 describes how forming smooth undulations on the entire surface of the chute under the granular material flow can suppress the flow of granular material in an overlapping or combined state, thereby suppressing uneven flow and splashing of granular material.

[0011] However, the inventions described in Patent Documents 3 and 4 are specifically designed for long-grained granules such as rice and granules with sticky surfaces such as parboiled rice, and are difficult to adapt to the different types, shapes, sizes, and flow rates of various grains and other granular materials.

[0012] Patent document 5 discloses a technique that allows the tilt angle of the chute to be varied by manually rotating a screw. That is, it describes how the quality of the grains can be determined optically by maintaining the normal flow trajectory of the grains by finely adjusting the tilt angle of the chute.

[0013] Existing technical documents

[0014] Patent documents

[0015] Patent Document 1: Japanese Patent Application Publication No. 63-084680

[0016] Patent Document 2: Japanese Patent Application Publication No. 63-093387

[0017] Patent Document 3: Japanese Patent Application Publication No. 2013-000684

[0018] Patent Document 4: Japanese Patent Application Publication No. 2013-043164

[0019] Patent Document 5: Japanese Published Patent No. 60-26011 Summary of the Invention

[0020] The problem that the invention aims to solve

[0021] The inventors of this invention believe that, as described in Patent Document 5, a simple operation that allows for a variable tilt angle of the chute can appropriately handle various types, shapes, sizes, and flow rates of granular materials such as grains. However, it remains unclear whether the tilt angle of the chute is appropriate for the various types, shapes, sizes, and flow rates of granular materials such as grains. For example, it is unclear what the appropriate tilt angle is to avoid "splashing" for non-spherical soybeans, long-grained rice, and sticky granules such as parboiled rice. In other words, the adjustment of the chute's tilt angle has always been done visually and intuitively by the operator, which may lead to deviations in sorting accuracy caused by the operator.

[0022] In view of the above-mentioned problems, the present invention addresses the following technical challenge: providing a particle splash detection device capable of quantitatively controlling the splashing of granular material flowing down a chute, and a particle sorting device equipped with the splash detection device. Furthermore, the present invention provides a particle sorting device equipped with a splash suppression device for suppressing splashing of the flowing granular material, which can be controlled based on the splash detection signal from the aforementioned splash detection device, thereby improving the sorting accuracy of the granular material.

[0023] Methods for solving problems

[0024] (1) A splash detection device for particulate matter, comprising: a conveying unit for conveying particulate matter; an imaging unit capable of imaging the particulate matter conveyed by the conveying unit; and a splash determination unit capable of determining whether there is splashing in the particulate matter conveyed on the conveying unit based on data obtained by the imaging unit.

[0025] (2) In the splash detection device, the imaging unit includes: a first imaging unit capable of imaging the particulate matter conveyed by the conveying unit from one side; and a second imaging unit capable of imaging the particulate matter from the other side opposite to the first imaging unit. The splash determination unit can determine whether there is splash in the particulate matter based on the detection result of the pixel offset between the image of the particulate matter captured by the first imaging unit and the image of the particulate matter captured by the second imaging unit.

[0026] (3) The particulate matter splash detection device includes a splash adjustment unit, which can suppress the splashing of the particulate matter conveyed by the conveying unit based on the judgment result of the splash discrimination unit.

[0027] (4) A particulate matter sorting device comprising the particulate matter splash detection device described in (3) above, the particulate matter sorting device comprising an injector capable of spraying air onto the particulate matter conveyed by the conveying unit, and the splash adjustment unit capable of adjusting the spraying time and / or spraying range of the injector based on the discrimination result of the splash discrimination unit.

[0028] (5) A particulate matter sorting device comprising the particulate matter splash detection device described in (1) or (2) above, wherein the conveying unit is a chute that causes the particulate matter to flow down in a certain direction, the particulate matter sorting device comprising: an injector capable of spraying air onto the particulate matter discharged from the chute; a chute tilt angle adjustment mechanism capable of adjusting the tilt angle of the chute; and a splash adjustment unit capable of suppressing splashing of the particulate matter flowing down the chute, wherein the splash adjustment unit is capable of adjusting the tilt angle of the chute and the spraying time and / or spraying range of the injector based on the discrimination result of the splash discrimination unit.

[0029] (6) A particulate matter sorting device comprising the particulate matter splash detection device described in (1) or (2) above, wherein the conveying unit is a belt conveyor that throws the particulate matter at a constant speed in the conveying direction so that it falls freely, the particulate matter sorting device comprising: an injector capable of spraying air onto the particulate matter discharged from the belt conveyor; and a splash adjustment unit capable of suppressing splashing of the particulate matter conveyed on the belt conveyor, wherein the splash adjustment unit is capable of adjusting, based on the determination result of the splash determination unit, any one of the following: the belt tension of the belt conveyor, the conveying speed of the belt conveyor, and the pressing force of the pressing roller of the belt conveyor that presses the particulate matter synchronously with the belt conveyor, as well as the spraying time and / or spraying range of the air from the injector.

[0030] Invention Effects

[0031] According to the invention described above, the imaging unit can determine whether there is splashing of flowing particulate matter, and measures to suppress particulate matter splashing can be implemented based on the splashing determination result. For example, by applying the invention to an optical particulate matter sorting device, the sorting accuracy of defective particles can be improved.

[0032] According to the invention described above, pixel shift can be quantitatively detected based on images of particulate matter captured by the first and second imaging units, and the presence or absence of splashing in the particulate matter can be determined with high precision.

[0033] According to the invention described above, the splashing of particulate matter can be suppressed by a splashing adjustment unit based on the splashing discrimination result.

[0034] According to the invention described above, the spray time and / or spray range of the jetting air of the jetting device based on the detection result of the pixel offset detection unit can be adjusted by the splash adjustment unit, and granular materials that are to be sorted can be reliably sorted.

[0035] Splash detection can be performed using the imaging unit on the optical sorting machine that is used to determine the quality of particulate matter. Therefore, there is no need to set up a new imaging unit for splash detection, and splash detection can be performed efficiently and at low cost using the existing imaging unit used for quality determination. Attached Figure Description

[0036] Figure 1 This is the control process before the optical sorting machine of this embodiment is put into operation.

[0037] Figure 2 This describes the imaging method of the imaging unit for imaging particles that deviate from their usual flow trajectory.

[0038] Figure 3 This indicates the method for representing pixel offset as a vertical offset.

[0039] Figure 4 This describes the threshold for the amount of splashing based on pixel offset.

[0040] Figure 5 This describes the imaging method of the imaging unit for imaging particles that deviate from their usual flow trajectory.

[0041] Figure 6 This indicates the method for representing pixel offset as a horizontal offset.

[0042] Figure 7 This indicates the pixel offset of the flowing granular material.

[0043] Figure 8 This is the control process during the operation of the optical sorting machine in this embodiment.

[0044] Figure 9 Explain the spray range of the injector.

[0045] Figure 10 This is a cross-sectional view illustrating the mechanism used to adjust the tilt angle of the slide.

[0046] Figure 11 This is a cross-sectional view illustrating another embodiment of the mechanism for adjusting the tilt angle of the slide.

[0047] Figure 12This is a flowchart showing the control process of the chute tilt angle based on the scattering rate of particulate matter.

[0048] Figure 13 It is a graph showing the relationship between the scattering rate and the number of tilt angle adjustments.

[0049] Figure 14 This is a control flowchart for another implementation of the chute tilt angle based on the particulate matter dispersion rate.

[0050] Figure 15 It is a graph showing the relationship between the scattering rate and the number of tilt angle adjustments. Detailed Implementation

[0051] Hereinafter, the particulate matter splash detection device of this embodiment will be described with reference to the accompanying drawings.

[0052] The particulate splash detection device of this embodiment is, for example, an optical particulate sorting device (optical sorter 1) for sorting particulate matter 2. Moreover, as the sorted material that flows down the chute 3 and is released from the lower end of the chute 3 and reaches the optical detection unit by free fall, in addition to grains such as rice, wheat, beans, and corn, glass or resin particulate matter 2, which are raw materials for industrial products, can also be appropriately selected.

[0053] (Splash detection during trial operation)

[0054] exist Figure 1 The following control flow is illustrated: During a trial run before the operational operation of the optical sorting machine 1 in this embodiment, splashing of the granular material 2 flowing down the chute 3 is detected, and adjustments are made based on the detection results of the splashing of the granular material 2 to suppress the splashing of the granular material 2. During the trial run before the operational operation of the optical sorting machine 1, when splashing occurs in the granular material 2 flowing down the chute 3, the granular material 2 is detected by the optical detection unit on a trajectory that deviates from the normal flow path as it is released from the lower end of the chute 3 and falls freely. Furthermore, necessary adjustments are made based on the splashing detection results of the optical detection unit to suppress the splashing of the granular material 2 flowing down the chute 3.

[0055] like Figure 2 As shown, the optical sorting machine 1 includes at least: a chute 3 that allows granules 2 to flow down; imaging units 4 and 5 that are capable of capturing images of granules 2 that are released from the lower end of the chute 3 and fall freely; and a control unit (not shown) that analyzes the image data obtained from the imaging units 4 and 5 to determine whether the product is qualified or unqualified, and outputs a removal signal to drive the ejector of the sorting unit when the product is determined to be unqualified.

[0056] Next, based on Figure 1The control flow describes the control structure of the splash detection device for particulate matter 2 in the optical sorting machine 1 of this embodiment. First, during the trial run before the optical sorting machine 1 is put into operation, the difference between the front image, which is the front image of the particulate matter 2, and the rear image, which is the rear image, is calculated by the pixel offset detection unit (not shown) provided in the control unit.

[0057] To explain in more detail, such as Figure 2 As shown, for the granular material 2 discharged from the lower end of the chute 3, a first imaging unit 4 capable of photographing the granular material 2 from one side (the front side in this embodiment) and a second imaging unit 5 capable of photographing the granular material 2 from the other side (the rear side in this embodiment) opposite to the first imaging unit 4 across the flow path 6 are used to capture front and rear images of the granular material 2, respectively. When the granular material 2 is discharged normally from the lower end of the chute 3 without splashing, it falls freely along the flow path 6 and is photographed at point A by the first imaging unit 4 and the second imaging unit 5. At this time, both the first imaging unit 4 and the second imaging unit 5 focus on monitoring point A, and the timing of the first imaging unit 4 and the second imaging unit 5 when the granular material 2 reaches point A is approximately the same.

[0058] On the other hand, when the granular material 2 splashes on the chute 3 and is released from the lower end of the chute 3 to fall freely, it flows down in a trajectory that deviates upwards relative to the normal downward flow path 6 (equivalent to...). Figure 2 The black ellipse of reference numeral 2 in the attached drawing is first captured by the first imaging unit 4 (refer to the black ellipse of reference numeral 2). Figure 2 (The image on the left). Next, from... Figure 2 The left side of the image shows the particle 2 falling slightly into the air and reaching... Figure 2 The timing of the position shown in the figure on the right is such that the black ellipse marked with reference 2 is captured by the second shooting unit 5.

[0059] That is, if both the first imaging unit 4 and the second imaging unit 5 are line sensors, and the monitoring point is A, then in Figure 2 As shown in the diagram on the left, when the first imaging unit 4 captures the black ellipse of reference numeral 2, the second imaging unit 5 does not monitor the black ellipse of reference numeral 2. Subsequently, if it becomes... Figure 2 As shown in the right-hand diagram, if the timing is incorrect, the first imaging unit 4 cannot capture the black ellipse of reference numeral 2, and the second imaging unit 5 monitors the black ellipse of reference numeral 2. That is, the imaging positions of the particles 2 captured by the first imaging unit 4 and the second imaging unit 5 are different, resulting in a time difference in the timing of the imaging by each imaging unit 4 and 5. Furthermore, because the captured image is offset from point A, the focus may be slightly blurred.

[0060] Therefore, when the front image of the particulate matter 2 captured by the first imaging unit 4 and the rear image of the particulate matter 2 captured by the second imaging unit 5 are superimposed, as shown... Figure 3 As shown, a pixel shift occurs in the downstream direction due to the time difference in shooting timing (hereinafter, the pixel shift in the downstream direction will be referred to as "vertical shift"). The pixel shift is quantitatively calculated as the difference between the front image and the rear image by a pixel shift detection unit in the control unit (not shown). The greater the splash of the particle 2 from the normal downstream trajectory 6, the greater the pixel shift.

[0061] In this embodiment, the configuration is such that the area of ​​pixel offset is calculated, and the splashing of particle 2 can be quantitatively determined based on the ratio of pixel offset to the overall area of ​​the captured particle 2. However, the method for quantitatively determining the splashing of particle 2 is not limited to area-based methods. For example, the splashing of particle 2 can also be quantitatively determined by calculating the separation distance between the center of gravity of particle 2 in the foreground image and the center of gravity of particle 2 in the background image.

[0062] Next, in Figure 1 In the control flowchart, it is determined whether the captured particulate matter 2 is a splashed particulate matter 2 (step S102). The degree of splashing is used to determine whether the captured particulate matter 2 is a splashed particulate matter 2. Then, as... Figure 4 As shown, the proportion of pixel offset detected by the pixel offset detection unit is used as the splash amount, and a predetermined threshold is set for this splash amount. The splash discrimination unit in the control unit (not shown) determines the splashing of the particle 2. The aforementioned pixel offset proportion can be, for example, set as the proportion of the sum of the pixel offset areas in the sum of the areas of each captured particle. In step S102, if the splash amount is less than the threshold A... Figure 4 If the area is identified as region 1), then it is determined that the particulate matter 2 is not the splashed particulate matter 2, and the process proceeds to step S109, ending the trial run and allowing normal operation to begin. Alternatively, it can be configured to... Figure 4 The threshold A for the amount of splashing is set to 0 (threshold A = 0). Even if a slight pixel offset is detected, it is considered that the particle 2 is the splashed particle 2 and the judgment process in step S103 is entered.

[0063] On the other hand, in the determination in step S102, when the splash amount is determined to be... Figure 4 The threshold A shown is above ( Figure 4 In the case of region 1 or region 2 (threshold A ≤ splash amount), if the particle 2 is determined to be splashed particle 2, the process proceeds to step S103. Then, in step S103, it is determined whether the splash amount based on the detected pixel offset is... Figure 4 The threshold B shown is above ( Figure 4 Area 3).

[0064] In step S103, it is determined that the splash amount based on pixel offset is not... Figure 4 The threshold B shown is above ( Figure 4 In the case of region 3) (threshold A ≤ splash amount < threshold B), the spray range of the spray nozzle used for sorting particulate matter 2 is controlled by the splash adjustment unit (step S108). Figure 9 The diagram illustrates an example of the spray range for the air jet of particulate matter 2. By extending the spray time of the jet injector, the spray range of the air jet in the downward flow direction of particulate matter 2 can be expanded. Therefore, air jets can be reliably sprayed onto particulate matter 2 that has pixel offset in the downward flow direction, thereby further improving the sorting accuracy of particulate matter 2.

[0065] On the other hand, in step S103, the amount of splashing based on pixel offset is determined to be... Figure 4 The threshold B shown is above ( Figure 4 In the case of region 3 (threshold B ≤ splash amount), the number of times the splash amount determined to be based on pixel offset exceeds the threshold B is counted (step S105), and the splashing of particulate matter 2 is adjusted by the splashing adjustment unit (step S106). In this embodiment, the adjustment of the splashing of particulate matter 2 is performed by changing the tilt angle of the chute 3 of the optical sorting machine 1 by the chute tilt angle adjustment mechanism described later, or by adjusting the flow rate of particulate matter 2.

[0066] After adjustments were made to suppress the splashing of particulate matter 2, as follows: Figure 1 The process is repeated as shown to monitor the splashing of particulate matter 2. In step S104, it is determined that the amount of splashing based on pixel offset, as determined in step S103, is above threshold B. Figure 4 The system checks whether the number N in region 3 exceeds a preset number (5 times in this embodiment). If it is determined that the number N exceeds the preset number, an alarm is displayed via a display device or light-emitting unit (not shown), and the feeder 8 that supplies granular material 2 to the chute 3 is stopped (see reference 3). Figure 10 (Step S107) etc.

[0067] (Splash detection during operation)

[0068] Figure 8 This describes the control process during operation after the aforementioned trial run. During the operation of the optical sorter 1, the splashing of the flowing particles 2 is monitored in the same manner as during the trial run, and necessary adjustments are made to the optical sorter 1.

[0069] During the operation of the optical sorting machine 1, and Figure 1Similarly, in step S101 of the trial operation, the difference between the front and rear images of the particle 2 is calculated using the pixel offset detection unit (not shown) provided in the control unit. Figure 7 The figure shows an image of the pixel shift of multiple particles 2 flowing down the chute 3 and being discharged from the lower end of the chute 3. As shown, by overlaying the front image of the particles 2 captured by the first imaging unit 4 and the rear image of the particles 2 captured by the second imaging unit 5, the portion other than the repeated pixels is detected as the pixel shift. Furthermore, the pixel shift detection unit quantitatively calculates the pixel shift as the difference between the front image and the rear image.

[0070] In this embodiment, the pixel offset is calculated as an area, but it is not necessarily limited to an area. It can also be configured to calculate the separation distance between the centroid position of the particle 2 in the front image and the centroid position of the particle 2 in the rear image.

[0071] Next, in Figure 8 In the control flowchart, it is determined whether the captured particle 2 is a splashed particle 2 (step S202). Regarding whether the captured particle 2 is a splashed particle 2, similar to the control during the trial run described above, the proportion of pixel offset detected by the pixel offset detection unit is used as the splash amount, and a predetermined threshold is set for this splash amount for determination (see [reference]). Figure 4 In step S202, if the splash amount is less than the threshold A, Figure 4 If region 1 is selected, then it is determined that particulate matter 2 is not splashed particulate matter 2, and the process is repeated to monitor whether particulate matter 2 splashes. Alternatively, it can be configured to... Figure 4 The threshold A for the amount of splashing is set to 0 (threshold A = 0). Even if a slight pixel offset is detected, the particle 2 is regarded as the splashed particle 2 and the judgment process in step S203 is entered.

[0072] On the other hand, in the determination in step S202, it is determined that the amount of splashing is... Figure 4 The threshold A shown is above ( Figure 4 In the case of region 1 or region 2 (threshold A ≤ splash amount), if the particle 2 is determined to be splashed particle 2, the process proceeds to step S203. Then, in step S203, it is determined whether the splash amount based on the detected pixel offset is... Figure 4 The threshold B shown is above ( Figure 4 Area 3).

[0073] In step S203, it is determined that the splash amount based on pixel offset is not... Figure 4 The threshold B shown is above ( Figure 4In the case of region 3) (threshold A ≤ splash amount < threshold B), the following control is performed in the same way as during the trial operation: based on the degree of splash amount based on pixel offset, the spray range of the sprayer that sprays air to the particulate 2 for sorting is expanded by the splash adjustment unit (step S208).

[0074] On the other hand, in S203, the amount of splashing based on pixel offset is determined to be... Figure 4 The threshold B shown is above ( Figure 4 In the case of region 3 (threshold B ≤ splash amount), for regions where the splash amount is determined to be above threshold B based on pixel offset, Figure 4 The number of times the spray pattern in region 3 is counted (step S205), and the following control is performed: the spray range of the jet nozzle is expanded by the spray adjustment unit according to the degree of splashing based on the pixel offset (step S206). The expansion range of the spray range in step S206 is larger than the expansion range of the spray range in step S208.

[0075] After controlling the expansion of the jet range of the injector's airflow through step S206, as follows Figure 8 The process is repeated to monitor whether the particles 2 are splashing particles 2. In step S204, it is determined whether the number N of times the pixel offset exceeds the threshold determined in step S203 exceeds a preset number (5 times in this embodiment). If the number N exceeds the preset number, an alarm is displayed using a display device (not shown), a light-emitting unit, etc., and the feeder 8 that supplies particles 2 to the chute 3 is stopped (see reference). Figure 10 (Step S207) etc.

[0076] As described above, the control methods during trial operation and operation have been explained. When setting the thresholds for the amount of splashing based on pixel offset, the same threshold can be set for both trial operation and operation, or different thresholds can be set for each. In the above embodiment, the amount of splashing is calculated based on the area of ​​the pixel offset and the ratio of the pixel offset to the overall area of ​​the particle 2, and each discrimination process is performed by setting thresholds. However, it is not limited to this method; a threshold can also be set for the ratio of the pixel offset. In the above embodiment, the amount of splashing based on pixel offset is calculated to determine the degree of splashing of the particle 2, but the scattering rate can also be calculated as a method to determine the degree of splashing. That is, the scattering rate can also be calculated based on the ratio of the number of splashed particles 2 per unit number of particles flowing down in the chute 3, and a threshold can be set for this scattering rate to perform each discrimination process. Furthermore, the amount of splashing can be calculated and a threshold can be set based on the separation distance between the center of gravity of the particle 2 in the front image and the center of gravity of the particle 2 in the rear image. Alternatively, a threshold can be set for the separation distance of the aforementioned center of gravity.

[0077] (Results of the comparative experiment)

[0078] In an optical sorting machine 1 equipped with the particulate matter splash detection device of this embodiment described above, a comparative test was conducted on the sorting accuracy of particulate matter 2. The comparative test was conducted under the following three conditions.

[0079] In test (1), the sprayer was operated on particles 2 that were judged to be of poor quality, regardless of whether particles 2 splashed or not, within the normal spray range.

[0080] In experiment (2), with a sorting rate of 99.99% for defective particles, regardless of whether particles 2 splashed, the spraying time of the injector was extended for all particles 2 that were judged to be defective, thereby expanding the spraying range of the airflow in the downward direction.

[0081] In experiment (3), the spraying time of the ejector was extended only for splashed defective particles to expand the spray range of the jet air in the downward direction. For defective particles that did not splash, the ejector was operated within the normal spray range, just like in experiment (1).

[0082] The results of the above comparative tests show that, under the conditions of test (2), the sorting rate of particles 2 that were determined to be defective particles was approximately 100%, but a large number of particles that were not defective particles were also sorted out, and about half of the particles 2 sorted out by the sprayer were not defective particles. On the other hand, under the conditions of test (3) conducted with the control of this embodiment, the sorting rate was higher than that of test (1), and most of the sorted particles 2 were actually defective particles.

[0083] Based on the results of the comparative tests above, it can be seen that by extending the spray time and expanding the spray range of the air jet only for the splashing particles 2, the sorting rate can be improved without significantly reducing the proportion of defective particles in the particles 2 that are sorted out as defective particles, thereby enabling high-precision sorting of particles 2.

[0084] (Regarding the slide tilt angle adjustment mechanism)

[0085] exist Figure 10 The figure shows a cross-sectional view of the chute tilt angle adjustment mechanism of this embodiment. As shown, a motor 30 is installed inside the optical sorting machine 1, and the operation of the motor 30 causes the shaft 31, which is directly or indirectly connected to the chute 3, to rotate. Furthermore, the chute 3, with its intersection with the bottom surface of the feeder 8 for supplying granules 2 as a fulcrum (Figure f), can adjust its tilt angle (Figure a) within the range shown by the dashed line in the figure.

[0086] Furthermore, the sliding groove tilt angle adjustment mechanism is not specifically limited to the one using the aforementioned motor 30 and shaft 31; for example, it can also be configured as follows: Figure 11 The structure shown is as follows. Specifically, it is configured such that a winding machine 40 is installed inside the optical sorting machine 1, and the operation of the winding machine 40 can wind the chain 41 that is directly or indirectly connected to the chute 3. Moreover, the chute 3 can be adjusted at its inclination angle (Figure a) within the range shown by the dotted line in the figure, with the intersection point with the bottom surface of the feeder 8 for supplying granules 2 as the fulcrum (Figure f).

[0087] The motor 30 and winding machine 40 of the chute tilt angle adjustment mechanism can change the tilt angle of the chute 3 under the control of the control unit of the optical sorting machine 1. Thus, when performing the splash adjustment in S106 during the above-mentioned trial operation, the tilt angle of the chute 3 is automatically changed to an appropriate value.

[0088] (Other implementation methods)

[0089] The control structure for applying the particulate matter splash detection device of this embodiment to the optical sorting machine 1 has been described above. However, it is not limited to the above embodiment, and various modifications as shown below can be made.

[0090] For example, as a principle for calculating the difference between the front and rear images of particle 2 using a pixel offset detection unit, in Figure 5 and Figure 6 The diagram illustrates the principle of lateral offset detection. Figure 5The diagram shows the planar position of the particulate matter 2 as it flows normally down the flow path 6 without splashing, i.e., passing through the planar line 7, as well as the first imaging unit 4 that captures the front image of the particulate matter 2 within the imaging range shown in the diagram, and the second imaging unit 5 that captures the rear image. Figure 5 The depth direction is the downward flow direction of the particulate matter 2. As shown in the figure, when photographing the splashed particulate matter 2, a pixel offset as shown in the figure occurs within the shooting range captured by the first shooting unit 4 and the second shooting unit 5.

[0091] That is, such as Figure 6 As shown, when the front image of the particle 2 captured by the first imaging unit 4 and the rear image of the particle 2 captured by the second imaging unit 5 are superimposed, a pixel shift as shown in the figure occurs. The pixel shift is quantitatively calculated by the pixel shift detection unit as the difference between the front and rear images of the particle 2. Similar to the above embodiment, the pixel shift can be calculated as an area, or it can be configured to calculate the separation distance between the centroid position of the particle 2 in the front image and the centroid position of the particle 2 in the rear image.

[0092] Regarding the above Figure 2 The detection principle of pixel offset (vertical offset) shown is as follows: Figure 5 The pixel offset (lateral offset) detection principle shown allows the pixel offset to be calculated in the pixel offset detection unit based on both principles. With this configuration, compared to detection methods using only one principle, the splashing of particles 2 can be detected with higher accuracy. Furthermore, when applied to the optical sorting machine 1, splashed particles 2 can be identified more reliably, improving the sorting accuracy of defective particles.

[0093] Furthermore, detection based on pixel offset (lateral offset), such as Figure 9 As shown, the horizontal spray range of the ejector can be expanded by the splash adjustment unit. By expanding the spray range in this way, the ejector can more reliably separate the splashed particles 2.

[0094] In the above embodiment, when adjusting for splash suppression during the trial run of the optical sorting machine 1 (step S106), the tilt angle of the chute 3 is automatically changed to an appropriate value by the control unit of the optical sorting machine 1. However, it is not limited to this. For example, it can be configured so that the operator can directly input the tilt angle of the chute 3 to change the tilt angle using a touch panel (not shown) or a remote operation PC provided on the optical sorting machine 1.

[0095] When the operator directly inputs the tilt angle of the chute 3 to change the tilt angle, the proportion of splashing particles 2 can be measured. As the proportion of splashing particles 2, for example, the scattering rate can be determined by calculating the ratio of the number of particles 2 identified as "splashing" by the splash detection unit to the total number of particles flowing down the chute, or the ratio of the number of splashing particles 2 per unit number of particles flowing down the chute. Empirically, if the tilt angle of the chute 3 increases, the flow velocity of the flowing particles 2 increases; on the other hand, due to air resistance and frictional resistance with the bottom surface of the chute 3, splashing of particles 2 is more likely, and the scattering rate increases. Conversely, if the tilt angle of the chute 3 decreases, splashing of particles 2 is less likely, and the scattering rate decreases. Based on this tendency, such as... Figure 13 As shown, it is possible to set an appropriate reference range for the scatter rate that can suppress the scatter rate while ensuring the required flow rate.

[0096] Furthermore, it is able to follow Figure 12 The process shown is used to adjust the inclination angle of the chute 3 so that the scattering rate of the particles 2 converges within the aforementioned appropriate reference range. For example, during a trial run before the optical sorting machine 1 is put into operation, the scattering rate of the particles 2 is measured. Then, it is determined whether the current scattering rate is within the acceptable range. Figure 13 Within the reference range (step S301). If the scattering rate is not outside the reference range (within the reference range), operation can begin without changing the tilt angle of the slide 3 (step S305).

[0097] On the other hand, if it is determined that the scattering rate is outside the reference range, it is then determined whether the scattering rate exceeds the reference range (step S302). If the scattering rate does not exceed the reference range, the tilt angle of the chute 3 is increased (step S304). If the scattering rate exceeds the reference range, the tilt angle of the chute 3 is decreased (step S303). The tilt angle of the chute 3 is adjusted until the measured scattering rate of the particles 2 converges within the reference range.

[0098] As other implementation methods, such as Figure 15 As shown, it can also be done according to Figure 14 The process shown is used to adjust the tilt angle of the chute 3 so that the scattering rate of the particles 2 is below a reference value. For example, during a trial run before the optical sorting machine 1 is put into operation, the scattering rate of the particles 2 is measured. Then, the tilt angle of the chute 3 is initialized (step S401), and it is determined whether the current scattering rate exceeds the reference value. Figure 15 The reference value is determined (step S402). If the scattering rate does not exceed the reference value, operation can begin without changing the tilt angle of the slide 3 (step S404).

[0099] On the other hand, if it is determined that the scattering rate exceeds the reference value, the tilt angle of the slide 3 is reduced (step S403), and the tilt angle of the slide 3 is repeatedly adjusted until the scattering rate becomes below the reference value.

[0100] In the above embodiments, in order to detect the presence or absence of splattering of particulate matter 2 and pixel offset, such as Figure 2 As shown, a first imaging unit 4 is provided in front of the granular material 2 discharged from the chute 3, and a second imaging unit 5 is provided in the rear. However, this embodiment is not limited to this one; imaging units can also be provided on the side of the flow path 6 to detect the separation state between the flow path 6 and the captured granular material 2 during normal flow, thereby detecting whether there is splashing of the granular material 2 and the degree of splashing. For example, it is possible to determine whether there is splashing of the granular material 2 based on the separation distance between the center of gravity of the flowing granular material 2 and the flow path.

[0101] In the above embodiments Figure 8 In the control flow shown during operation, in step S206, the spray range of the air jet is increased by the spray adjustment unit based on the degree of splashing based on the pixel offset. However, it can also be configured to adjust the tilt angle of the chute 3. Moreover, it can also be configured to adjust the tilt angle of the chute 3 after the spray range of the air jet has been expanded a predetermined number of times. That is, if the splashing of the particulate matter 2 is large, the pixel offset also becomes large. In this way, compared with dealing with it by adjusting the jet alone, readjusting the tilt angle of the chute 3 can effectively suppress the splashing of the particulate matter 2 and reduce the scattering rate, thereby improving the sorting accuracy of the particulate matter 2.

[0102] In the above embodiments, an embodiment in which the particle splash detection device is applied to the optical sorting machine 1 has been described, but it is not limited to the optical sorting machine 1 and can be widely used as a unit for detecting the splash of particles 2.

[0103] In the above embodiments, an embodiment of applying the particulate matter splash detection device of the present invention to an optical sorting machine 1 has been described. Conventionally, in the optical sorting machine 1, imaging units are provided before and after the particulate matter 2 in order to determine its quality. Such imaging units for quality determination can be used as a first imaging unit 4 and a second imaging unit 5, and splash detection can be performed based on the obtained images. In this way, it is not necessary to add new imaging units for splash detection, and it is not necessary to carry out significant specification changes to the optical sorting machine 1, thus enabling low-cost detection of particulate matter 2 splash.

[0104] Furthermore, in the above embodiment, the conveying unit of the optical sorting machine 1 was described primarily as the chute 3 that allows the granules 2 to flow down in a certain direction. However, it is not limited to the chute 3; the conveying unit could also be a belt conveyor (not shown) that throws the granules 2 at a constant speed in the conveying direction, allowing them to fall freely. To suppress splashing of the granules 2 on the belt conveyor, any one of the following can be adjusted by the splash adjustment unit: the belt tension of the belt conveyor, the conveying speed of the belt conveyor, and the pressing force of the pressing roller that presses the granules 2 against the belt conveyor synchronously with the belt conveyor.

[0105] Several embodiments of the present invention have been described above, but these embodiments are provided for easy understanding of the invention and are not intended to limit the invention. The present invention can be modified and improved without departing from its spirit, and equivalents are included. Furthermore, the scope of protection and combinations or omissions of the constituent elements described in the specification are possible within the scope of solving at least some of the above-described problems or achieving at least some of the effects.

[0106] Explanation of reference numerals in the attached figures

[0107] 1 Optical sorting machine

[0108] 2 granular substances

[0109] 3 grooves

[0110] 4 First Shooting Unit

[0111] 5 Second shooting unit

[0112] 6. Flow trajectory

[0113] 7 Passing through the plane line

[0114] 8 feeders

[0115] 30 electric motors

[0116] 31 axis

[0117] 40 winding machine

[0118] 41 Chains.

Claims

1. A device for detecting splashing of particulate matter, characterized in that, have: A conveying unit that conveys granular materials; The imaging unit is capable of imaging the granular material conveyed by the aforementioned conveying unit; and The splash detection unit is capable of determining, based on data obtained by the imaging unit, whether there is splashing in the granular material being transported on the conveying unit. The aforementioned shooting unit is equipped with: The first imaging unit is capable of imaging the granular material conveyed by the aforementioned conveying unit from the front side of the granular material's flow path; and The second imaging unit is capable of taking pictures from the rear side of the aforementioned granular material's flow path. The aforementioned splash detection unit can determine whether there is splashing in the particles based on the detection result of at least one of the vertical and horizontal offsets of the pixel offset between the image of the particles captured by the first imaging unit and the image of the particles captured by the second imaging unit.

2. The particulate matter splash detection device according to claim 1, characterized in that, The aforementioned splash detection device includes a splash adjustment unit, which can suppress the splashing of the granular material conveyed by the aforementioned conveying unit based on the judgment result of the aforementioned splash discrimination unit.

3. A granular material sorting device, characterized in that, The above-mentioned particulate matter sorting device includes the particulate matter splash detection device as described in claim 2. The aforementioned granular material sorting device includes an ejector capable of spraying air onto the granular material conveyed by the aforementioned conveying unit. The aforementioned splash adjustment unit can adjust the spray time and / or spray range of the ejector based on the discrimination result of the aforementioned splash discrimination unit.

4. A granular material sorting device, characterized in that, The above-mentioned particulate matter sorting device includes the particulate matter splash detection device as described in claim 1. The aforementioned conveying unit is a chute that directs the granular material downwards in a certain direction. The above-mentioned granular material sorting device includes: The ejector is capable of spraying air at the granular material discharged from the chute. A chute tilt angle adjustment mechanism, capable of adjusting the tilt angle of the aforementioned chute; and The splash adjustment unit is capable of suppressing the splashing of the particulate matter in the aforementioned chute flow. The aforementioned splash adjustment unit can adjust the tilt angle of the aforementioned chute and the jet spray time and / or spray range of the aforementioned jet based on the discrimination result of the aforementioned splash discrimination unit.

5. A granular material sorting device, characterized in that, The above-mentioned particulate matter sorting device includes the particulate matter splash detection device as described in claim 1. The aforementioned conveying unit is a belt conveyor that transports the aforementioned granular material at a constant speed. The above-mentioned granular material sorting device includes: A jet injector capable of spraying air onto the granular material discharged from the aforementioned belt conveyor; and A splash control unit is provided to suppress splashing of the granular material being conveyed on the aforementioned belt conveyor. The aforementioned splash adjustment unit can adjust, based on the discrimination result of the aforementioned splash discrimination unit, any one of the following: the belt tension of the aforementioned belt conveyor, the conveying speed of the aforementioned belt conveyor, the pressing force of the aforementioned granules pressed onto the pressing roller of the aforementioned belt conveyor synchronously with the aforementioned belt conveyor, and the spraying time and / or spraying range of the aforementioned ejector.

Images