Workpiece measuring device and workpiece measuring method

Abstract

A workpiece measuring device comprises a first light source that illuminates a workpiece with linear light, a second light source that illuminates the workpiece with ordinary illumination, an image acquisition unit for the workpiece, a displacement mechanism for repositioning the workpiece, a control unit, and a measuring unit that determines 2D and 3D data of the workpiece based on the images acquired by the image acquisition unit. The control unit causes the image acquisition unit to perform an image acquisition process on the workpiece when the workpiece is being repositioned by the displacement mechanism and the first and second light sources are illuminated simultaneously.The measuring unit extracts image data corresponding to a point of interest on the workpiece from the successively recorded images and arranges the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D and 3D data of the point of interest based on this map.

Description

Technical area

[0001] The present invention relates to a workpiece measuring device and a workpiece measuring method for obtaining 2D data and 3D data of a workpiece to be measured. General state of the art

[0002] The section light method is known as a method for non-contact height measurement of a workpiece. In the section light method, an image of a workpiece irradiated with line light is captured, and the height of the workpiece is determined from the captured image using the principle of triangulation. Patent Document 1 discloses a 3D profile measuring device for workpieces using the section light method. In the measuring device of Patent Document 1, brightness values ​​of pixels obtained by scanning of a point of interest in an image are arranged in a timeline to determine brightness changes of the point of interest.

[0003] Patent Document 2 discloses an apparatus that creates a 3D model of a workpiece from its 3D shape and a 2D structural image. The measuring apparatus of Patent Document 2 simultaneously acquires the 3D data and 2D data of the workpiece, and therefore includes a first light source and a first light receiving section for 3D measurement, and a second light source with a different wavelength from the first light source and a second light receiving section for 2D measurement.

[0004] However, when using a measuring device that only acquires the 3D data of the workpiece, as in Patent Document 1, a separate measurement step is required to obtain the 2D data of the workpiece. However, according to the measuring device in Patent Document 2, a light source and a camera are required for both the 3D measurement and the 2D measurement of the workpiece, making the device more complex. Prior art documentsPatent documents Patent Document 1: JP 2015-105883 A Patent Document 2: JP 2006-162386 A Brief description of the inventionTask of the invention

[0005] The present invention has for its object to provide a workpiece measuring apparatus and a workpiece measuring method with which 2D data and 3D data of a workpiece can be measured with high work efficiency without making the apparatus complicated.

[0006] A workpiece measuring device according to one aspect of the present invention comprises a first light source that irradiates a workpiece to be measured with line light, a second light source that irradiates the workpiece with ordinary illumination light, an image pickup unit that captures images of the workpiece irradiated with the line light and the ordinary illumination light and its surroundings, a displacement mechanism that relatively displaces the workpiece in a predetermined conveying direction, a control unit that controls the operation of the image pickup unit, the first light source, the second light source and the displacement mechanism, and a measuring unit that acquires 2D data and 3D data for the workpiece based on the images acquired by the image pickup unit, wherein the control unit causes the image pickup unit to be in a statein which the workpiece is displaced by the displacement mechanism and the first light source and the second light source are illuminated simultaneously, an image acquisition process is carried out on the workpiece with a fixed camera scale unit, wherein the measuring unit extracts image data corresponding to a point of interest of the workpiece from the images successively acquired with the camera scale unit, and lines up the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D data and 3D data of the point of interest based on the brightness distribution map.

[0007] A workpiece measuring method according to another aspect of the present invention acquires 2D data and 3D data of a workpiece, wherein images of the workpiece are acquired with a fixed camera scale unit while the workpiece is displaced and the workpiece is simultaneously irradiated with line light and ordinary illumination light, wherein the measuring unit extracts image data corresponding to a point of interest of the workpiece from the images sequentially acquired with the camera scale unit, lines up the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D data and 3D data of the point of interest based on the brightness distribution map. Short description of the characters

[0008] They show: Fig. 1 is a schematic view illustrating in a simplified manner a hardware configuration of a workpiece measuring device according to an embodiment of the present invention; Fig. 2 is a block diagram illustrating the electrical configuration of the workpiece measuring device; Fig. 3(A)-(C) are schematic views illustrating procedures for measuring the height of a workpiece by the light-section method; Fig. 4(A) is a view illustrating the taking of an image of a point of interest of the workpiece; Fig. 4(B) is a view illustrating the taking of an image of a point of interest of the workpiece; Fig. 4(C) is a view illustrating the taking of an image of a point of interest of the workpiece; Fig. 4(D) is a view illustrating the taking of an image of a point of interest of the workpiece; Fig. 5(A) an example of a brightness distribution map of the point of interest and Fig. 5(B) is a curve diagram showing the brightness values ​​on the line VB-VB from Fig. 5(A) illustrates; Fig. 6(A)-(E) are explanatory views illustrating the process for deriving 2D data and 3D data of the workpiece from the brightness distribution map; Fig. 7 is a flowchart illustrating processing for deriving 2D data and 3D data of the workpiece using the workpiece measuring apparatus of the present embodiment; and Fig. 8(A)-(D) are explanatory views illustrating the process of deriving 2D data and 3D data of the workpiece from the brightness distribution map according to a modification example. Embodiment of the invention

[0009] An embodiment of the present invention will be described in detail below with reference to the figures. The workpiece measuring device of the present invention can be applied to a wide variety of 2D and 3D measurements on workpieces to be measured, including various industrial products, semi-finished products, mechanical components, electronic components, food products, agricultural products, and the like. For example, the workpiece measuring device of the present invention is useful when performing 2D / 3D measurements on a component mounted on a printed circuit board as a workpiece. Fixture configuration

[0010] Fig. 1 is a schematic view schematically illustrating the hardware configuration of a workpiece measuring device of the present embodiment. The workpiece measuring device 1 includes a first light source 2, a second light source 3, a camera device 4 (image pickup unit), a displacement motor 5 (displacement mechanism), and a control unit 6. The workpiece measuring device 1 is a device for deriving 2D data (brightness measurement data) and 3D data (height measurement data) of a workpiece W on a tray 51. Here, as an example, a computer mouse is shown placed on the tray 51 as the workpiece W. The surface of the tray 51 serves as a reference height plane for height measurement. When the workpiece W is a component on a printed circuit board, the tray 51 is the printed circuit board on which the component is mounted.

[0011] The first light source 2 is a light source that generates slit-shaped light and irradiates the workpiece W to be measured with line light SL. The first light source 2 can be applied to a light source device including a laser light source and optical elements that fan out the laser light generated by the light source and convert it into slit-shaped light. In the present embodiment, the example shown is that the first light source 2 is arranged to irradiate the workpiece W vertically from above with line light SL.

[0012] The second light source 3 irradiates the workpiece W with ordinary illumination light TL. Fig. In Figure 1, for the sake of simplicity, the ordinary illumination light TL is shown as a conically widening scattered light. However, in fact, the ordinary illumination light TL is omnidirectional illumination light that irradiates the workpiece W with light rays from all directions. The second light source 3 may employ a light source device in which, for example, circuit boards with a plurality of LEDs installed in a matrix are arranged in a ring shape, each with a different orientation. As long as the workpiece W can be irradiated with omnidirectional illumination light, there are no particular restrictions on the arrangement of the second light source 3.

[0013] The camera device 4 acquires images of the workpiece W irradiated with the line light SL and the ordinary illumination light TL and its surroundings. The camera device 4 has a recording axis AX that is inclined with respect to the direction perpendicular to the support 51. The camera device 4 is thus equipped with a recording axis AX that is inclined with respect to the projection axis of the line light SL. These axis arrangements are arrangements for three-dimensional measurement of the workpiece W. The configuration can also be such that the recording axis AX is arranged in the vertical direction and the production axis of the line light SL is arranged inclined with respect to the recording axis AX.

[0014] The displacement motor 5 is the drive source of a displacement mechanism that relatively displaces the workpiece W in a predetermined conveying direction. Examples of the manner of relatively displacing the workpiece W include displacement of the workpiece W and the tray 51 in the workpiece conveying direction F while the measuring system formed by the first light source 2, the second light source 3, and the camera device 4 is stationary, and scanning displacement of the measuring system in the workpiece conveying direction F while the workpiece W and the tray 51 are stationary. In the former case, the displacement motor 5 is a drive source of a conveyor or the like that displaces the workpiece W and the tray 51, and in the latter case, it is a drive source for displacing the measuring system along a guide rail or the like.

[0015] The control unit 6 is formed by a microcomputer or a PC and controls the operations of the first light source 2, the second light source 3, the camera device 4 and the displacement motor 5. Specifically, the control unit 6 controls, among other things, the operation of irradiating line light SL by the light source 2, the operation of irradiating ordinary illumination light TL by the second light source 3, the operation of capturing an image of the workpiece W by the camera device 4 and the operation of conveying the workpiece W by the displacement motor 5, that is, the scanning operation. Electrical configuration of the workpiece measuring device

[0016] Fig. Figure 2 is a block diagram illustrating the electrical configuration of the workpiece measuring device 1. The camera device 4 includes an image pickup element 41, an image memory 42, a measuring unit 43, a setting storage unit 44, and an interface unit 45. The image pickup element 41 is a sensor consisting of a photoelectric converter on which pixels are arranged in a matrix. A CMOS sensor is preferably used as the image pickup element 41, which can specify an ROI (region of interest) that determines the readout area of ​​the pixels.

[0017] The image data acquired by the image pickup element 41 is temporarily stored in the image memory 42. The measuring unit 43 acquires 2D data and 3D data of the workpiece W based on the images of the workpiece W acquired by the image pickup process, that is, the image data stored in the image memory 42. In the present embodiment, the example shown is that the camera device 4 is equipped with the measuring unit 43, but the control unit 6 or another external device may also be equipped with the measuring unit 43. Various setting data and parameters related to the measuring process of the measuring unit 43 are stored in the setting storage unit 44. Setting values ​​related to a reference position for dividing 2D regions and 3D regions in a brightness distribution map M described below may also be stored in the setting storage unit 44.The interface unit 45 is an interface circuit for performing data exchange with the control unit 6.

[0018] The measuring unit 43 functionally includes an image alignment unit 431, a height calculation unit 432, a brightness calculation unit 433, and an ROI setting unit 434. The image alignment unit 431 extracts image data corresponding to points of interest of the workpiece W from the images that the image pickup element 41 successively captures with a predetermined camera scale. Furthermore, the image alignment unit 431 arranges the extracted image data on a timeline and generates a brightness distribution map M ( Fig. 5) for the positions of interest.

[0019] To obtain the 3D data of the workpiece W, the height calculation unit 432 performs processing to determine the height of the points of interest of the workpiece W using the light-section method based on the brightness distribution map M. To obtain the 2D data of the workpiece W, the brightness calculation unit 433 performs processing to determine the brightness of the points of interest based on the brightness distribution map M. The ROI setting unit 434 sets the ROI of the image pickup element 41. The higher the dimension of the ROI in the workpiece conveyance direction F, that is, the dimension of the ROI in the profile direction, the more the height dimension of the workpiece W to be measured expands, thus enabling three-dimensional measurement of a higher workpiece W.

[0020] The control unit 6 causes the workpiece W to be displaced in the workpiece conveying direction F by means of the displacement mechanism equipped with the displacement motor 5 while simultaneously illuminating the first light source 2 and the second light source 3. In this state, it causes the camera device 4 to perform the image capturing operation on the workpiece W at a predetermined frame rate. The control unit 6 thus causes the image capturing operation of the camera device 4 at a respective distance proportional to the size of the pixel columns of the image capturing element 41, or in other words, at a camera scale unit proportional thereto. By executing predetermined control programs, the control unit 6 functions as a camera control unit 61, a light source control unit 62, a motor control unit 63, a data storage unit 64, and an interface unit 65.

[0021] The camera control unit 61 controls the camera device 4 and causes it to record the workpiece W moving relative to it with the specified camera scale unit. Through this image recording, a plurality of images of the workpiece W are acquired and stored in the image memory 42. The camera scale unit is set such that a proportional relationship is established between the relative displacement distance of the workpiece W and the size on the pixel columns of the image pickup element 41.

[0022] The light source control unit 62 simultaneously illuminates the first light source 2 and the second light source 3 at the time the workpiece W is captured by the camera device 4. In this way, the workpiece W can simultaneously receive the reflected light of both the line light SL and the ordinary illumination light TL into the camera device 4. The motor control unit 63 controls the displacement motor 5 while the camera device 4 is capturing the workpiece W, causing the workpiece W and the tray 51 to be displaced at a predetermined displacement speed in the workpiece conveying direction F. The 2D data and 3D data of the workpiece W sent from the measuring unit 43 of the camera device 4 are stored in the data storage unit 64. The interface unit 65 is an interface circuit for performing data exchange with the camera device 4. Height measurement using the light section method

[0023] With reference to Fig. 3(A)-(C) follows a description of the 3D measurement (height measurement) that can be carried out on the workpiece measuring device 1 using the light section method. As in Fig. 3(A), the example shown here is that a cuboid workpiece W is placed on the support 51 as the object to be measured. The camera device 4 and the first light source 2 generating the line light SL are used for the height measurement. Unlike in Fig. 1 is in Fig. 3(A) shows the example that the camera device 4 is arranged such that the recording axis AX is vertical, and the first light source 2 is arranged such that the projection light axis of the line light SL has an intersection angle θ with the recording axis AX.

[0024] Fig. 3(B) shows a frame image F01 obtained by the camera device 4 at a scanning position where the workpiece W is irradiated with line light SL. When the line light SL is irradiated onto an area including the workpiece W, reflection light RL1 from the tray 51 in the vicinity of the workpiece W, that is, from the reference height, and reflection light RL2 from the upper surface of the workpiece W are captured by the camera device 4. Since the line light SL is obliquely incident and the workpiece W has a height, in the frame image F01, the X coordinates of the reflection light RL1 and the reflection light RL2 are observed at different positions from each other. Specifically, the reflection light RL1 appears at coordinate x11, while the reflection light RL2 appears at coordinate x12, which is upstream of the coordinate x11 in the workpiece conveyance direction F.

[0025] The radiation of the line light SL onto the point P0 from Fig. 3(A) is treated as a position with the calculated height=0. As in Fig. As shown in Figure 3(C), based on the principle of triangulation using the intersection angle θ, height data with a height h1 at coordinate x11 and a height h2 at coordinate x12 can be obtained. Subsequently, additional frames F02 and F03 are acquired sequentially, so that images of different locations on the workpiece W are obtained. In this way, height data of coordinates x21 and x22 are obtained in frame F02, and height data of coordinates x31 and x32 are obtained in frame F03. Of course, the camera scale unit is actually a much smaller distance than the one shown as an example.

[0026] The multiple height data sets from the above scanning process are combined, allowing 3D data of the workpiece W to be determined. The height data obtained in the individual images F01, F02, F03 are based on the result of irradiating different X-coordinate positions with the reflected light RL1, RL2. Therefore, during data merging, a height table can be created in which, for example, the height data of coordinate x12 obtained in the individual image F01 in the area of ​​the workpiece W and the height data of coordinate x12 obtained at a later scanning position in the area of ​​the storage area 51 are coordinated. Simultaneous acquisition of 2D and 3D data

[0027] The following is a description of the simultaneous acquisition of 2D data and 3D data on the workpiece measuring device 1. Fig. 4A-4D are views illustrating the acquisition of an image of a point of interest N of the workpiece W. In Fig. 4A-4D show a state in which the workpiece W is displaced relative to the image pickup element 41 of the camera device 4 in the workpiece conveying direction F while taking images of the workpiece W with the specified camera scale unit.

[0028] The workpiece W is simultaneously irradiated with the line light SL generated by the first light source 2 and the ordinary illumination light TL (not shown) generated by the second light source 3. Therefore, line reflection light RL, which is reflected light of the line light SL irradiated onto the workpiece W, and ordinary reflection light RT, which is reflected light of the ordinary illumination light TL, are simultaneously incident on the image pickup element 41. Line reflection light RL1 from the position h=0 and line reflection light RL2 from the height h are shown as the line reflection light RL.

[0029] A point of interest N is shown on the workpiece W, for which 2D data and 3D data are to be determined. The size of the point of interest N in the workpiece conveying direction F corresponds to the distance by which the workpiece W is displaced in the recording interval between one individual image and the next. Pixel columns L1-L10, with which the image recording element 41 is provided, are pixel columns with a number of pixels corresponding to the recording intervals. The point of interest N is recorded sequentially at the pixel columns L1-L10 during the displacement in the workpiece conveying direction F in ten consecutively recorded individual images F1-F10. Fig. Figures 4A-4D show the recording state of individual images F3-F6 at the third to sixth positions. The setting is such that the line reflection light RL1 enters the pixel column L4 at h=0.

[0030] For single image F3 in Fig. 4A, the point of interest N has not yet reached the irradiation position of the line light SL. Therefore, image data F3-L3 obtained in frame F3 at the pixel column L3 where the point of interest N is captured are image data consisting only of ordinary reflected light RT. The same applies to the frames F1, F2 captured before frame F3.

[0031] In single frame F4 from Fig. 4B, the point of interest N is captured at the pixel column L4 adjacent to the pixel column L3 downstream in the workpiece conveying direction F. Also, in the frame F4, ordinary reflection light RT from the workpiece W is incident on the pixel column L4. Line reflection light RL1 from the area h=0, which is located at the same position as the point of interest N in the workpiece conveying direction F, is also incident on the pixel column L4. Therefore, image data F4-L4 obtained in the frame F4 at the pixel column L4 where the point of interest N is captured is image data in which the line reflection light RL1 is superimposed on the ordinary reflection light RT.

[0032] In frame F5, the point of interest N is captured at pixel column L5. In frame F5, ordinary reflected light RT from the workpiece W also enters the pixel column L5, and line reflected light RL2 from the height h region of the workpiece W also enters the pixel column L5. Therefore, image data F5-L5 obtained in frame F5 at the pixel column L5 where the point of interest N is captured is image data consisting of ordinary reflected light RT and line reflected light RL2.

[0033] At the time of taking the single image F6 of Fig. 4D, however, the point of interest N passes the irradiation position of the line light SL. Image data F6-L6 obtained in frame F6 at the pixel column L6 where the point of interest N is recorded are therefore image data consisting exclusively of ordinary reflected light RT. Fig. In Figures 4A-4D, the line light SL is simply depicted as linear light, while actual line light SL has a Gaussian distribution of luminous intensity in the workpiece conveying direction F. Therefore, image data F6-L6 also occur in which the line reflected light RL2 overlaps part of the ordinary reflected light RT. Images F7-F10, acquired after frame F6, are images in which only ordinary reflected light RT is incident.

[0034] As discussed above, the individual images F1-F10, which contain the image data F3-L3-F6-L6 from Fig. 4A-4D, temporarily in image memory 42 ( Fig. 2). The image alignment unit 431 of the measuring unit 43 extracts the image data corresponding to the point of interest N from the individual images F1-F10 stored in the image memory 42. Furthermore, the image alignment unit 431 arranges the extracted image data on a timeline and generates a brightness distribution map for the point of interest N. The same process is repeated for other points of interest N on the workpiece W.

[0035] Fig. Figure 5(A) is a view showing an example of a brightness distribution map M of the point of interest N. The x-direction in the figure is the direction in which the image data is lined up on the timeline and is a direction of a profile expressed by the height data of the workpiece W. The y-direction is a width direction of the workpiece W orthogonal to the workpiece conveyance direction F and the traveling direction of the line light SL. Fig. 5(B) is a graph showing the brightness values ​​on the line VB-VB from Fig. 5(A) illustrates.

[0036] The brightness distribution map M from Fig. Figure 5(A) was created by arranging the image data F1-L1-F10-L10 acquired for the point of interest N in the X direction for individual images F1-F10. The brightness distribution map M thus shows the change in brightness in the individual images F1-F10 for a single point of interest N.

[0037] As in Fig. As shown in Figure 4B, the image data F4-L4 contains line reflection light RL1 from the area h=0. Thus, in the area F4-L4 of the brightness distribution map M, brightness data D11 corresponding to the line reflection light RL1 is measured. As shown in Fig. As shown in Figure 4B, the image data F5-L5 contains line reflection light RL2 from the area of ​​height h of the workpiece W. Thus, in the area F5-L5 of the brightness distribution map M, brightness data D12 is measured, which corresponds to the line reflection light RL2. Ordinary reflection light RT, in turn, is contained in all image data F1-L1-F10-L10. As shown in Fig. Therefore, as shown in Figure 5(B), brightness data D2 corresponding to the ordinary reflected light RT is measured in all areas of the brightness distribution map M. A high brightness value is shown on the VB-VB line, at which the brightness data D12 of the line reflected light RL2 exhibits a peak. Since the line light SL has a Gaussian luminous intensity distribution, as discussed above, the brightness data D12 exhibits a triangular waveform rather than a rectangular waveform.

[0038] Based on the brightness distribution map M discussed above, the height calculation unit 432 of the measuring unit 43 derives height data of the point of interest N, i.e., 3D data, and the brightness calculation unit 433 derives brightness data of the point of interest N, i.e., 2D data. Fig. 6(A)-(E) are explanatory views illustrating the procedure for deriving 2D data and 3D data of the workpiece from the brightness distribution map M.

[0039] In the data derivation, the image alignment unit 431 provides on the brightness distribution map M a 2D area M1 for obtaining 2D data and a 3D area M2 for obtaining 3D data as shown in Fig. 6(A). The 3D area M2 is set to an area in which height information of the workpiece W based on the line light SL appears in the brightness distribution map M, and the 2D area M1 is set to the remaining area. In the example shown in Fig. In the brightness distribution map M shown in Figure 5(A), the area where the height information appears is the area of ​​image data F4-L4-F10-L10, so this area is set as the 3D area M2. In this case, the 2D area M1 is the area of ​​image data F1-L1-F3-L3.

[0040] The size of the 3D region M2 can be adjusted by the ROI setting unit 434 by specifying the size of the ROI of the image pickup element 41. The image pickup element 41 has a plurality of pixels arrayed in a matrix, and the two-dimensional array area of ​​these pixels is the image area in which images can be acquired. The ROI setting unit 434 performs ROI setting by specifying a portion of the overall image area captured by the image pickup element 41. By specifying an ROI with a large dimension in the workpiece conveying direction F, the measurable height dimension of the workpiece W can be expanded. The ROI setting unit 434 performs ROI setting with a range suitable for the type of workpiece W. The setting values ​​for the 2D region M1 and the 3D region M2 based on the ROI setting are stored in the setting storage unit 44.

[0041] As in Fig. As shown in Figure 6(B), the brightness calculation unit 433 extracts a predetermined number of brightness data at a data acquisition line G1 arbitrarily set in the 2D area M1. There may be one or more data acquisition lines G1. Fig. 6(C) is a graph showing the brightness data extracted at random intervals along the data acquisition line G1. The ordinary reflected light RT is reflected light from the non-directional ordinary illumination light TL, so some fluctuations in the brightness values ​​occur in the brightness data along the data acquisition line G1. The brightness calculation unit 433 derives a piece of brightness data by performing processing such as obtaining an average value, a maximum value, or a median value of the extracted brightness data group. This piece of brightness data is the 2D data of the point of interest N.

[0042] As in Fig. As shown in Fig. 6(D), the height calculation unit 432 extracts a predetermined number of brightness data items in the 3D area M2 at a data acquisition line G2 that intersects the brightness data D12 corresponding to the highest point of the workpiece W in the X direction. Fig. 6(E) is a graph showing the brightness data extracted at arbitrary intervals along the data acquisition line G2. In the waveform of this brightness data, a peak value TD of the brightness data D12 augmented by the brightness component of the ordinary reflected light RT appears. The peak value TD is the brightness data that precisely indicates the height h of the workpiece W. The height calculation unit 432 obtains the peak value TD by, for example, a center of gravity calculation or a phase calculation and sets it as the height position of the brightness data D12. Similarly, a peak value is obtained for the brightness data D11 and set h=0 as the height reference position. The height calculation unit 432 acquires 3D data by calculating the height of the point of interest N using the light-section method based on the respective peak values ​​of the thus acquired brightness data D11, D12. Data derivation processing process

[0043] Fig. 7 is a flowchart illustrating the processing for deriving the 2D data and 3D data of the workpiece W using the workpiece measuring device 1 of the present embodiment. At the start of the measurement of the workpiece W, the ROI setting unit 434 performs ROI setting for the image pickup element 41 (step S1). If the height of the workpiece W has been estimated in advance, this ROI setting is linked to the setting of the 2D area M1 and 3D area M2 discussed above. The size of the 2D area M1 and the 3D area M2 can be stored in advance in the setting storage unit 44, and this setting can be read out in step S1.

[0044] Next, scanning of the workpiece W is performed (step S2). During scanning, the light source control unit 62 of the control unit 6 simultaneously illuminates the first light source 2 and the second light source 3 and irradiates the workpiece W with line light SL and ordinary illumination light TL. The motor control unit 63 drives the displacement motor 5, causing the workpiece W to be displaced at a predetermined speed in the workpiece conveying direction F. The camera control unit 61 controls the camera device 4 to continuously capture individual images of the workpiece W at the predetermined camera scale unit. The acquired individual image data is temporarily stored in the image memory 42 (step S3).

[0045] Subsequently, the measuring unit 43 reads the image data from the image memory 42 and executes the processing for deriving the measurement data of the workpiece W. First, the measuring unit 43 sets the points of interest N for the workpiece W (step S4). The points of interest N are set to n positions by finely dividing the surface of the workpiece W. Next, the image arranging unit 431 sets a counter N=1 and extracts image data of the first point of interest N from the individual images in the image memory 42 (step S5). The image data is, for example, the image data shown in Fig. 4A-4D. Furthermore, the image aligning unit 431 arranges the extracted image data on a timeline and generates a brightness distribution map for the point of interest N (step S6). A concrete example of the brightness distribution map M is shown in Fig. 5(A).

[0046] Subsequently, the height calculation unit 432 reads the brightness data from the 3D area M2 of the brightness distribution map M (step S7). The 3D area M2 is as shown by way of example on the brightness distribution map M of Fig. 6(A) and corresponds to the extraction of brightness data along the data acquisition line G2 from Fig. 6(D). The height calculation unit 432 now carries out processing for determining the center position of the line light SL (line reflection light RL) by, as exemplified in Fig. 6(E), the peak value TD of the waveform of the extracted brightness data is determined (step S8). Thus, the position of the height h of the workpiece W is determined. Then, the height calculation unit 432 derives the 3D data corresponding to the height of the point of interest N by referring to the height reference position h=0 using the light-section method (step S9).

[0047] Then, the brightness calculation unit 433 reads the brightness data from the 2D area M1 of the brightness distribution map M (step S10). The 3D area M2 is as exemplified on the brightness distribution map M of Fig. 6(A) and corresponds to the extraction of brightness data along the data acquisition line G1 from Fig. 6 (B). Then, the brightness calculation unit 433 derives the 2D data corresponding to the brightness of the point of interest N by, among other things, determining the average value of the extracted brightness data (step S11). In steps S9 and S11, the respective derived 3D data and 2D data are transmitted to the control unit 6 and stored in the data storage unit 64 (step S12).

[0048] Then, the measuring unit 43 judges whether the counter for the number of points of interest N to be processed has reached the value of n set in step S4, that is, whether N=n is satisfied (step S13). If N=n is not satisfied (NO in step S13), the measuring unit 43 increments the counter by N=N+1 (step S14), returns to step S5, and performs the same processing for the next point of interest N. Conversely, if N=n is satisfied (YES in step S13), the measuring unit 43 terminates the processing.

[0049] As stated above, according to the workpiece measuring apparatus 1 of the present embodiment, in the light-section method, 3D data of the workpiece W can be obtained by capturing line reflection light RL of the line light SL of the first light source 2 irradiating the workpiece W. Also, 2D data of the workpiece W can be obtained by capturing ordinary reflection light RT of the ordinary illumination light TL of the second light source 3 irradiating the workpiece W. The control unit 6 causes the camera device 4 to perform the capturing operation while causing the workpiece W to be displaced and the first light source 2 and the second light source 3 to illuminate simultaneously. Therefore, the camera device 4 can acquire individual images from which both 2D data and 3D data can be extracted.

[0050] The brightness distribution map M of the point of interest N, which is created from the acquired frame group, is brightness information based on the line reflection light RL and the ordinary reflection light RT, and is brightness distribution information including 2D and 3D information of the point of interest N. Consequently, the 2D data and 3D data of the point of interest N can be derived from the brightness distribution map M. In this way, according to the workpiece measuring device 1, the 2D data and 3D data of the workpiece W can be obtained using a single camera device 4 with a single scanning operation of the workpiece W. Therefore, the workpiece W can be measured with high work efficiency and without increasing the complexity of the device. Variation example

[0051] Fig. 8(A)-(D) are explanatory views illustrating the process for deriving 2D data and 3D data of the workpiece W from a brightness distribution map MA according to a modified example. In the modified example, the example shown is that, when the 3D area in the brightness distribution map MA is set to an area larger than a specified width, the measuring unit 43 calculates a brightness average value of the brightness distribution map MA to obtain the 2D data.

[0052] As in Fig. As shown in Fig. 8(A), in the brightness distribution map MA according to the modification example, the size of the 3D area in the profile direction (x-direction) is set larger than the size of the 3D area in Fig. 6(A). The size of the 3D region can be expanded by the ROI setting unit 434 performing ROI setting expanded in the workpiece conveyance direction F. By expanding the 3D region, the dimension for measuring the height of the workpiece W can be increased. Consequently, for the brightness data D11 of the height reference, brightness data D12A can be measured, which appears at a correspondingly distant position on the brightness distribution map MA. Thus, the height measurement of a higher workpiece W is enabled.

[0053] In the case of a brightness distribution map MA in which a sufficiently large height dimension of the 3D region is achieved, for example, in the case where the size of the 3D region in the profile direction is set to 2 to 5 times that of the 2D region, the relative proportion of the line light SL (line reflected light RL) in the images captured by the camera device 4 decreases. Consequently, the average brightness value of the brightness distribution map MA is approximated to the brightness data corresponding to the 2D data.

[0054] Based on this knowledge, the measuring unit 43 extracts in the modification example as in Fig. 8(B) shows brightness data at arbitrary intervals along a data acquisition line G3 intersecting the brightness data D12 in the x-direction. Fig. Figure 8(C) is a graph showing the distribution of the extracted brightness data in the x-direction. The brightness calculation unit 433 calculates the average brightness value of the multiple pieces of brightness data extracted along the data acquisition line G3. This average brightness value is treated as the 2D data derived by approximation for the point of interest N of the workpiece W.

[0055] The height calculation unit 432 similarly creates a curve diagram indicating the brightness data based on the plurality of brightness data items extracted along the data acquisition line G3, as shown in Fig.8(D). The height calculation unit 432 determines the peak value TD of the brightness data D12, as in the above-discussed embodiment, and acquires 3D data by determining the height of the point of interest N using the light-section method. According to this modification example, by extracting brightness data along a single data acquisition line G3, 2D data and 3D data can be obtained, thereby simplifying the measurement work. Invention contained in the above embodiment

[0056] A workpiece measuring device according to one aspect of the present invention comprises a first light source that irradiates a workpiece to be measured with line light, a second light source that irradiates the workpiece with ordinary illumination light, an image pickup unit that captures images of the workpiece irradiated with the line light and the ordinary illumination light and its surroundings, a displacement mechanism that relatively displaces the workpiece in a predetermined conveying direction, a control unit that controls the operation of the image pickup unit, the first light source, the second light source and the displacement mechanism, and a measuring unit that acquires 2D data and 3D data for the workpiece based on the images acquired by the image pickup unit, wherein the control unit causes the image pickup unit to be in a statein which the workpiece is displaced by the displacement mechanism and the first light source and the second light source are illuminated simultaneously, an image acquisition process is carried out on the workpiece with a fixed camera scale unit, wherein the measuring unit extracts image data corresponding to a point of interest of the workpiece from the images successively acquired with the camera scale unit, and lines up the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D data and 3D data of the point of interest based on the brightness distribution map.

[0057] A workpiece measuring method according to another aspect of the present invention acquires 2D data and 3D data of a workpiece, wherein images of the workpiece are acquired with a fixed camera scale unit while the workpiece is relatively displaced and the workpiece is simultaneously irradiated with line light and ordinary illumination light, wherein the measuring unit extracts image data corresponding to a point of interest of the workpiece from the images sequentially acquired with the camera scale unit, lines up the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D data and 3D data of the point of interest based on the brightness distribution map.

[0058] According to the workpiece measuring device or method described above, in the light-section method, 3D data of the workpiece can be obtained by causing the reflected light of the line light of the first light source, which is irradiated onto the workpiece, to be captured at the image pickup unit. Also, 2D data of the workpiece can be obtained by causing the reflected light of the ordinary illumination light of the second light source, which is irradiated onto the workpiece, to be captured at the image pickup unit. The ordinary illumination light is omnidirectional illumination light that irradiates the workpiece with light rays from all directions. The control unit causes the image pickup operation of the image pickup unit while simultaneously illuminating the first light source and the second light source.Therefore, for each shot along the camera scale unit, the image acquisition unit can acquire images from which 2D data and 3D data can be extracted.

[0059] The measuring unit also extracts image data corresponding to the point of interest of the workpiece from the images successively acquired during the movement of the workpiece. By arranging the extracted image data on a timeline, a brightness distribution map for the point of interest is generated. This brightness distribution map is brightness information based on the reflected light of the line light and the ordinary illumination light, and brightness distribution information including 2D and 3D information of a point of interest. Consequently, the 2D data and 3D data of the point of interest can be derived from the brightness distribution map. In this way, according to the workpiece measuring device or method, 2D data and 3D data of the workpiece can be obtained using a single image acquisition unit with a single scanning operation of the workpiece.Therefore, the workpiece can be measured with high work efficiency and without increased complexity of the device.

[0060] In the above workpiece measuring device, it is preferable that the measuring unit designates, in the brightness distribution map, a region in which height information based on the line light appears as a 3D region for obtaining the 3D data, and designates the remaining region as a 2D region for obtaining the 2D data.

[0061] According to this workpiece measuring device, since the area in the brightness distribution map where no height information appears is set as a 2D area, the 2D data and the 3D data can be obtained with reliable discrimination from each other.

[0062] In the above workpiece measuring device, it is preferable that the measuring unit determines the height of the point of interest based on the information of the 3D area by the light section method and thus obtains the 3D data and obtains the 2D data of the point of interest based on the brightness data of the 2D area.

[0063] According to this workpiece measuring device, it is possible to determine the three-dimensional shape of the point of interest based on the light section method and to determine the color, pattern, etc. of the point of interest based on the brightness data.

[0064] In the above workpiece measuring device, it is preferable that, in the case where the 3D area in the brightness distribution map is set to an area of ​​more than a specified width, the measuring unit calculates a brightness average value of the brightness distribution map to obtain the 2D data.

[0065] In the case of a brightness distribution map that achieves a sufficiently large height dimension of the 3D region, the proportional contribution of line light in the acquired image decreases. Consequently, the average brightness value of the brightness distribution map approximates the brightness data corresponding to the 2D data. According to the workpiece measurement device described above, the derivation of the 2D data can be simplified.

[0066] In the above workpiece measuring device, the image pickup unit includes an image pickup element on which pixels are arrayed in a matrix, wherein the measuring unit performs an ROI specification in which the used part is specified from the entire image area captured by the image pickup element, whereby the 3D area can be set based on the ROI specification size.

[0067] According to this workpiece measuring device, the ROI target size can be appropriately adjusted according to the expected height of the workpiece, whereby the 3D data of the workpiece can be accurately obtained. Explanation of reference symbols 1 workpiece measuring device 2 first light source 3 second light source 4 Camera device (image recording unit) 41 Image pickup element 43 measuring unit 431 Image alignment unit 432 height calculation unit 433 Brightness calculation unit 434 ROI setting unit 5 Displacement motor (displacement mechanism) 6 Control unit 6 F Workpiece transport direction SL line light TL ordinary lighting light RL line reflection light RT ordinary reflected light W workpiece N point of interest M brightness distribution map QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2015-105883 A

[0004] JP 2006-162386 A

[0004]

Claims

[1] Workpiece measuring device, comprising: a first light source that irradiates a workpiece to be measured with line light, a second light source that illuminates the workpiece with ordinary illuminating light, an image recording unit that records images of the workpiece irradiated with the line light and the ordinary illumination light and its surroundings, a displacement mechanism that relatively displaces the workpiece in a specified conveying direction, a control unit that controls the operation of the image pickup unit, the first light source, the second light source and the displacement mechanism, and a measuring unit that determines 2D data and 3D data for the workpiece based on the images obtained by the image acquisition unit, wherein the control unit causes the image pickup unit to perform an image pickup operation with a fixed camera scale unit on the workpiece in a state where the workpiece is displaced by the displacement mechanism and the first light source and the second light source are illuminated simultaneously, wherein the measuring unit extracts image data corresponding to a point of interest of the workpiece from the images sequentially captured by the camera scale measuring unit, and arranges the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D data and 3D data of the point of interest based on the brightness distribution map. [2] The workpiece measuring device according to claim 1, wherein the measuring unit determines, in the brightness distribution map, a region in which height information based on the line light appears as a 3D region for obtaining the 3D data, and determines the remaining region as a 2D region for obtaining the 2D data. [3] The workpiece measuring device according to claim 2, wherein the measuring unit determines the height of the point of interest based on the information of the 3D area by the light section method to obtain the 3D data and obtains the 2D data of the point of interest based on the brightness data of the 2D area. [4] The workpiece measuring device according to claim 2 or 3, wherein the measuring unit calculates a brightness average value of the brightness distribution map to obtain the 2D data when the 3D area in the brightness distribution map is set to an area of more than a predetermined width. [5] A workpiece measuring device according to any one of claims 2 to 4, wherein the image pickup unit comprises an image pickup element on which pixels are arrayed in a matrix, wherein the measuring unit performs an ROI specification in which the used part of the entire image area captured by the image pickup element is specified, whereby the 3D area is set based on the ROI specification size. [6] A workpiece measuring method that acquires 2D data and 3D data of a workpiece, wherein images of the workpiece are acquired at a fixed camera scale unit while the workpiece is relatively displaced and the workpiece is simultaneously irradiated with line light and ordinary illumination light, wherein the measuring unit extracts image data corresponding to a point of interest of the workpiece from the images successively acquired with the camera scale unit, and lines up the image data on a timeline to generate a brightness distribution map of the point of interest, and derives 2D data and 3D data of the point of interest based on the brightness distribution map.

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