Single-ply detection system, single-ply detection program

Abstract

The objective is to provide a veneer detection system that can ensure a wide sensing range for deposited veneers. [Solution] This disclosure comprises a marker projection device 2 that projects line-shaped markers M onto a deposited veneer T deposited in XYZ space, a camera 3 that photographs the deposited veneer T with the projected markers M at unit time Δt intervals, and a calculation unit 4 that detects veneers B deposited on the surface based on a plurality of images G input from the camera 3. The marker projection device 2 emits planar light L around an axis Ax parallel to the X axis and scans the deposited veneer T in the Y direction with the planar light L.

Description

Technical Field

[0001] The present disclosure relates to a single-board detection system mounted on a single-board feeder.

Background Art

[0002] Conventionally, a technique of a single-board feeder that picks up deposited single boards one by one from the surface layer and sends them out toward a conveyance line is known. For example, Patent Document 1 introduces a technique of irradiating a deposited single board with laser light, photographing the deposited single board on which the laser light is projected with a camera, analyzing the photographed image by pixel number analysis, etc., and detecting the single board on the surface layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, a pickup device for lifting a single board is disposed above the deposited single board in the single-board feeder. For this reason, for example, it is difficult to move a two-dimensional sensor or the like over the entire area above the deposited single board, and there is a problem that the detection range becomes narrow. Further, since the deposited single board has a large surface area, it is also difficult to move the entire deposited single board with respect to a fixed two-dimensional sensor or the like due to restrictions on the working space.

[0005] Therefore, an object of the present disclosure is to provide a single-board detection system capable of expanding the detection range of a single board.

Means for Solving the Problems

[0006] To solve the above problems, the single-layer detection system of this disclosure comprises a marker projection device that projects line-shaped markers onto a deposited single-layer plate deposited in XYZ space, a camera that photographs the deposited single-layer plate with the projected markers at unit time intervals, and a calculation means that detects a single-layer plate deposited on the surface based on a plurality of images input from the camera. The marker projection device is positioned offset in the Y direction from the center of the deposited single-layer plate, and the camera is positioned offset in the Y direction from the center of the deposited single-layer plate in an inclined position from the Z direction. The marker projection device emits planar light around an axis parallel to the X-axis and scans the deposited single-layer plate in the Y direction using the planar light. [Effects of the Invention]

[0007] According to the single-plate detection system of this disclosure, the system includes a marker projection device that projects line-shaped markers onto a deposited single-plate, and the marker projection device is rotatable around an axis parallel to the X-axis. The marker projection device emits planar light around an axis parallel to the X-axis and scans the deposited single-plate in the Y-direction with the planar light. Therefore, the detection range of the single-plate can be expanded without moving the marker projection device above the entire area of ​​the deposited single-plate. [Brief explanation of the drawing]

[0008] [Figure 1] (a) an oblique view and (b) a side view of a single-sheet feeder equipped with a single-sheet detection system, which represents one embodiment of the present disclosure. [Figure 2] This is a block diagram of a single-plate feeder. [Figure 3] (a) A schematic diagram of an image containing a marker, and (b) A schematic diagram showing each marker contained in multiple images. [Figure 4] (a) A schematic diagram of point cloud information, (b) A schematic diagram of the height map, and (c) A schematic diagram of the region. [Figure 5] (a) A schematic diagram showing the surface veneer, and (b) A schematic diagram showing the positional relationship between the surface veneer and the pickup device. [Figure 6] This is an explanatory diagram showing the operation of a single-plate feeder. [Figure 7] This is an explanatory diagram showing the operation of a single-plate feeder. [Modes for carrying out the invention]

[0009] Hereinafter, an embodiment of this disclosure implemented in a single-sheet detection system 1 mounted on a single-sheet feeder 10 will be described with reference to the drawings. In the following description, the orientation of the XYZ axes is set as shown in Figure 1. "Position" refers to the coordinates (x, y, z) in XYZ space.

[0010] As shown in Figure 1(a), the single-plate detection system 1 comprises a marker projection device 2 that projects line-shaped markers M onto deposited single-plates T accumulated in XYZ space, a camera 3 that photographs the deposited single-plates T with the projected markers M at unit time Δt intervals, and a calculation unit 4 (see Figure 2) that detects single-plates B deposited on the surface based on multiple images G input from the camera 3. The marker projection device 2 emits planar light L around an axis Ax parallel to the X-axis and scans the deposited single-plates T in the -Y direction with the planar light L. The planar light L can be, for example, a two-dimensional laser beam.

[0011] The marker projection device 2 rotates clockwise around axis Ax at angular velocity ω and projects a line-shaped marker M onto the deposited single plate T by irradiating it with planar light L. The orientation of the marker projection device 2 at time t (time t: elapsed time from the start of scanning) is represented by its tilt ωt with respect to the Z axis.

[0012] As shown in Figure 1(b), the marker projection device 2 is positioned at a location offset in the +Y direction from the center of the deposited veneer T, and at an angle of ωt from the Z direction (vertical direction). The camera 3 is positioned at a location offset in the +Y direction from the center of the deposited veneer T, and at an angle of θ degrees from the Z direction. The marker projection device 2 and the camera 3 are positioned at approximately the same location. The position and angular velocity ω of the marker projection device 2 and the position and orientation of the camera 3 are known.

[0013] As shown in Figure 2, the veneer feeder 10 includes a veneer detection system 1, a pickup device 14 for picking up veneers B detected by the veneer detection system 1, and a PC 11. The veneers B handled by the veneer feeder 10 are roughly rectangular and irregularly shaped boards with a width of approximately 1 m, a length of approximately 2 m, and a thickness of approximately 2 mm to 4 mm. The veneers B are made of wood, and their surfaces have fine irregularities such as grain and knots, as well as slight warping. On the mounting table 20, the stacked veneers B are stacked in the Z direction, with the short side of each veneer B arranged along the X direction and the long side arranged along the Y direction.

[0014] The pickup device 14 includes a fastening device 15 for fastening the single sheet B and a suction device 18 for picking up the single sheet B fastened to the fastening device 15. The fastening device 15 includes a plurality of fastening tools 16 arranged in the X direction and a lifting mechanism 17 for individually raising and lowering the plurality of fastening tools 16. The tip of each fastening tool 16 is provided with a piercing nail 16a (see Figures 6 and 7) for piercing the single sheet B. The suction device 18 includes a roller 19 for feeding the picked-up single sheet B in the -Y direction.

[0015] The fastening device 15 of the pickup device 14 activates the lifting mechanism 17 to lower the fastening tool 16 toward the single sheet B. The fastening device 15 drives the piercing nail 16a into the single sheet B and raises the fastening tool 16. The suction device 18 of the pickup device 14 picks up the raised single sheet B. After that, the fastening device 15 removes the piercing nail 16a from the single sheet B. The suction device 18 sends the single sheet B to the conveyor line with the roller 19.

[0016] The PC11 comprises a CPU (Central Processing Unit) 12 that functions as a control means for controlling the single-board detection system 1 and the pickup device 14, a storage unit 13, and an arithmetic unit 4.

[0017] The memory unit 13 is composed of a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM is a non-volatile memory or the like, and stores various programs, files and parameters used in the programs. The RAM temporarily stores data used when executing various programs.

[0018] The arithmetic unit 4 is a program (single-plate detection program) stored in the memory unit 13 and functioning as the arithmetic unit 4 when executed by the CPU 12. It is also possible to implement the arithmetic unit 4 on the CPU 12.

[0019] The arithmetic unit 4 includes a marker position calculation unit 41 that calculates the position of the marker M in the XYZ space using the position and orientation of the marker projection device 2 and the position and orientation of the camera 3 based on markers M (M1, M2, ···, Mn) included in a plurality of images G; a point cloud information generation unit 42 that accumulates the positions of the markers M to generate three-dimensional point cloud information J; an edge detection unit 43 that detects an edge E based on the point cloud information J; a region detection unit 44 that detects regions R (R1, R2, ···, Rn) surrounded by the edge E; and a single-plate detection unit 45 that detects the surface single plate B based on the orientation of each edge E constituting the region R.

[0020] As shown in FIG. 3(a), the camera 3 captures the deposited single plate T on which the marker M is projected every unit time Δt and generates a plurality of images G.

[0021] As shown in FIG. 3(b), the marker position calculation unit 41 detects the position of each marker M (M1, M2, ···, Mn) included in the plurality of images G. Here, the marker M included in the image G is photographed with an expansion in the X direction compared to the actual object toward the +Y direction due to the inclination ωt of the marker projection device 2 and the inclination θ of the camera 3. The marker position calculation unit 41 corrects the distortion of the image G using the position and orientation of the camera 3 and the position and orientation of the marker projection device 2 based on the position of the marker M in the image G, and calculates the position of the marker M in the XYZ space.

[0022] As shown in Figure 4(a), the point cloud information generation unit 42 maps each point on the marker M to the XYZ space based on the position of the marker M in the XYZ space, and generates three-dimensional point cloud information J. Here, the marker M included in image G is represented as darker (lower brightness) where the height is low and brighter (higher brightness) where the height is high. Each point included in the point cloud information J has the brightness of the corresponding point on the marker M. At this time, the point cloud information generation unit 42 applies an image filter to image G to generate point cloud information J that reduces the effects of fine undulations such as wood grain and knots on the surface of the veneer B, as well as slight warping.

[0023] As shown in Figure 4(b), the edge detection unit 43 collects point cloud information J and generates a height map J'. The height map J' is represented by a brightness gradient obtained by collecting the brightness of each point in the point cloud information J.

[0024] The edge detection unit 43 detects steps based on the height map J'. Specifically, the edge detection unit 43 converts the brightness gradient of the height map J' into numerical values ​​representing height (hereinafter referred to as height values), and detects steps at positions where the difference in height values ​​compared to the surrounding area exceeds a predetermined threshold. At this time, the edge detection unit 43 calculates the rate of change of the height value at the step location, and if the rate of change is below a predetermined threshold, it removes the step as noise and does not determine it as edge E. The edge detection unit 43 determines any steps that were not removed as noise as edges E.

[0025] As shown in Figure 4(c), the region detection unit 44 detects the region R (R1 to R9) surrounded by the edge E.

[0026] As shown in Figure 5(a), the single-layer detection unit 45 detects a single layer B on the surface based on the orientation of the edge E surrounding the region R. Specifically, when observed from left to right (-X direction), if the left side of edge E reverses and rises, and the right side reverses and descends, the regions R3 and R7 from the edge E whose orientation reversed and rose to the edge E whose orientation reversed and descended are detected as single layer B on the surface. Note that the observation direction may also be the +X direction.

[0027] As shown in Figure 5(b), the veneer detection unit 45 calculates the range of X values ​​in which the surface veneers B are located. The splint attachment device 15 lowers only the splint attachment tools 16 that are located within the range of X values ​​in which the surface veneers B are located, thereby enabling the picking of only the surface veneers B.

[0028] Next, the operation of the single-plate feeder 10 with the above configuration will be explained based on Figures 6 and 7.

[0029] As shown in Figure 6(a), the deposited veneer T is placed on the mounting platform 20. As shown in Figure 6(b), the marker projection device 2 scans the deposited veneer T in the -Y direction with planar light L. At this time, the camera 3 takes a picture of the deposited veneer T on which the marker M is projected every unit time Δt. The calculation unit 4 detects the surface veneer B based on the image G input from the camera 3 and calculates the range of X values ​​in which the surface veneer B is located. As shown in Figure 6(c), the piercing device 15 lowers the piercing tool 16 positioned within the range of X values ​​and pierces the veneer B with the piercing nail 16a.

[0030] As shown in Figure 7(a), the fastening device 15 raises the fastening tool 16 to which the single sheet B has been fastened. As shown in Figure 7(b), the suction device 18 suctions the single sheet B. After that, the fastening device 15 removes the piercing nails 16a. As shown in Figure 7(c), the roller 19 sends the single sheet B to the conveyor line.

[0031] The single-layer detection system 1 with the above configuration includes a marker projection device 2 that projects a line-shaped marker M onto the deposited single-layer plate T. The marker projection device 2 emits planar light L around an axis Ax parallel to the X-axis, and scans the deposited single-layer plate T in the Y-direction with the planar light L. Therefore, the detection range of single-layer plates B can be expanded without moving the marker projection device 2 above the entire area of ​​the deposited single-layer plate T. By expanding the detection range, surface single-layer plates B can be detected more accurately from a deposited single-layer plate T containing single-layer plates B of irregular sizes.

[0032] Furthermore, because the marker projection device 2 is positioned at a location offset in the +Y direction from the center of the deposited single plate T, and tilted ωt from the Z direction, the scanning range can include the area below the attachment device 15 of the pickup device 14. Because the camera 3 is positioned at a location offset in the +Y direction from the center of the deposited single plate T, and tilted θ degrees from the Z direction, the imaging range can include the area below the attachment device 15 of the pickup device 14.

[0033] Furthermore, since point cloud information J is generated using projected plane light L, and surface layer single plate B is detected using point cloud information J, computationally intensive image processing is unnecessary, significantly reducing processing time.

[0034] Furthermore, this disclosure is not limited to the embodiments described above, and it is possible to implement the invention by arbitrarily changing the configuration of each part without departing from the spirit of the invention. [Explanation of Symbols]

[0035] 1. Single-Plate Detection System 2 Marker projection device 3 cameras 4 Arithmetic section 10 Single-Plate Feeder 11 PC 12 CPU 13 Storage section 14. Pickup device 15 Sticking device 16 Piercing tool (a: Piercing nail) 17 Lifting mechanism 18 Adsorption device 19 Laura 20 mounting platform 41 Marker position calculation unit 42 Point cloud information generation section 43 Edge detection unit 44 Area detection unit 45 Single-plate detection unit B Solid wood T-type deposited veneer L plane light M Marker Ax axis G Image J point cloud information J' Height Map E-edge R region

Claims

1. The system comprises a marker projection device that projects line-shaped markers onto a deposited veneer in XYZ space, a camera that photographs the deposited veneer onto which the markers are projected at unit time intervals, and a calculation means that detects veneers deposited on the surface based on a plurality of images input from the camera. The marker projection device is positioned at a location offset in the Y direction from the center of the deposited single plate. The camera is positioned at a location offset in the Y direction from the center of the deposited single plate, and tilted from the Z direction. The marker projection device emits planar light around an axis parallel to the X-axis, and scans the deposited single plate in the Y-direction with the planar light. The calculation means, A marker position calculation means calculates the position of the marker in XYZ space using the position and orientation of the marker projection device and the position and orientation of the camera, based on the positions of the markers included in a plurality of the aforementioned images. A point cloud information generation means that collects the positions of the markers and generates three-dimensional point cloud information, An edge detection means for detecting edges based on the point cloud information, A region detection means for detecting the region surrounded by the aforementioned edge, A veneer detection system comprising veneer detection means for detecting the veneer of the surface layer based on the orientation of each edge surrounding the region.

2. The aforementioned marker includes brightness, Each point included in the point cloud information has the brightness described above. The single-plate detection system according to claim 1, wherein the edge detection means collects the point cloud information, generates a height map represented by a light-dark gradient, converts the light-dark gradient into a height value which is a numerical value representing height, and detects a step difference based on the height value.

3. The single-plate detection system according to claim 2, wherein the edge detection means calculates the rate of change of the height value at the step position, and removes the step as noise if the rate of change is below a threshold.

4. A single-plate detection program that functions as the calculation means described in claim 1 when executed by a computer, The calculation means, A marker position calculation means calculates the position of the marker in XYZ space using the position and orientation of the marker projection device and the position and orientation of the camera, based on the positions of the markers included in a plurality of the aforementioned images. A point cloud information generation means that collects the positions of the markers and generates three-dimensional point cloud information, An edge detection means for detecting edges based on the point cloud information, A region detection means for detecting the region surrounded by the aforementioned edge, A veneer detection program includes veneer detection means for detecting the veneer of the surface layer based on the orientation of each edge surrounding the region.

Images