JP2013181774A - Measurement instrument and processing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique for measuring an opening space between objects regardless of a shape of the opening space between the objects.SOLUTION: A measuring instrument measures a distance of an opening space in a vertical direction from a reference surface downward to a measurement surface between a measurement target object 110 having the measurement surface and a reference object 120 having the reference surface with an opening space formed by the measurement surface therebetween. The measuring instrument includes measurement means 10 having an imaging part 22 for photographing an area including the measurement surface, the opening space and the reference surface, detection means for detecting a boundary between the reference surface and the opening space from a photographed image on the basis of a change in a luminance value on the photographed image photographed by the imaging part 22, calculation means for converting a distance from the reference surface to the boundary on the photographed image into an actual distance to calculate a distance of the opening space, and display processing means for displaying the distance of the opening space calculated by the calculation means on an indicator.

Description

  The present invention relates to a measuring apparatus that measures a gap between objects and a processing method thereof.

  Conventionally, when measuring the gap between objects, for example, a caliper or a gap gauge (taper gauge) is used (Patent Document 1). The measurement of the gap between the objects is performed on a processed product that has been subjected to sheet metal processing, press processing, or the like in the manufacturing process of various industrial products such as automobile bodies and airplane wings.

  Specifically, in the inspection process after press working, for the press sheet metal clamped on the inspection tool (inspection mold) in which a plurality of spacers are arranged, the press sheet metal and the inspection object are measured using a gap gauge. The gap between the mold and the mold is measured at multiple points, and the work to measure the distortion is performed.

  In this inspection process, there is also a procedure for confirming the shape of the peripheral portion of the press sheet metal with a trim line. In this procedure, the horizontal distance from the trim line formed in the inspection mold to the press sheet metal cut is measured, and thereby the deviation from the design shape is measured.

JP 2009-257881 A

  In an inspection using a gap gauge, for example, there is a step of measuring a gap (edge, hole) on a press sheet metal. In this case, since it is necessary to insert a gap gauge (tapered portion) into the gap, accurate measurement cannot be performed when there is not enough depth in the gap or when a space for defeating the gap gauge cannot be secured (FIG. 21). (See (a) and FIG. 21 (b)).

  Even if a gap gauge is inserted into a hole or the like, it is necessary to read the scale formed on the surface of the gap gauge with the naked eye of the user, so the reading cannot be performed accurately depending on the insertion angle of the hole or the like. There is a possibility.

  As a method for coping with this, there is a method in which the gap is measured by removing the press sheet metal after filling the gap or the like, and measuring the thickness of the remaining clay. It takes time and effort.

  Further, there is a method of measuring the shape of the entire press sheet metal by using a laser three-dimensional sensor unit, and thereby measuring the distortion of the press sheet metal. However, in this case as well, complicated work increases and the apparatus becomes large, and it cannot be said that it is a realistic method in consideration of work time and cost.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of measuring a gap between objects regardless of the shape of the gap between objects.

  In order to solve the above-described problem, an aspect of the present invention is an example in which a measurement target object having a measurement surface and a reference object having a reference surface in which a gap is formed between the measurement surfaces are from above the reference surface. A measuring device that measures a distance of a gap along a vertical direction to the measurement surface, the measuring unit having an imaging unit that images a region including the measurement surface, the gap, and the reference surface; and the imaging unit. Detection means for detecting a boundary between the measurement surface and the gap from the captured image based on a change in luminance value on the captured image, and a distance from the reference surface to the boundary on the captured image And calculating means for calculating the distance of the gap, and display processing means for displaying the distance of the gap calculated by the calculation means on a display.

  According to the present invention, the gap between objects can be measured regardless of the shape of the gap between objects.

It is a figure which shows the outline | summary of the measuring device which has arranged the sensor unit concerning one embodiment of this invention. 2 is a diagram showing an outline of an internal configuration of a sensor unit 10. FIG. It is a figure which shows an example of the measurement screen. It is a figure which shows an example of the conversion table. FIG. 3 is a diagram for explaining an outline of calibration of a sensor unit 10. 5 is a diagram illustrating an example of a calibration screen 80. FIG. It is a figure which shows an example of a functional structure of each unit in a measuring device. It is a flowchart which shows an example of the flow of a process of a measuring device. It is a flowchart which shows an example of the flow of a process of a measuring device. It is a figure which shows an example of the support part 11 of the sensor unit 10 concerning Embodiment 2. FIG. 10 is a flowchart illustrating an example of a processing flow of the measurement apparatus according to the second embodiment. It is a top view which shows an example of a structure of the press sheet metal 110 and the type | mold 120 for a test | inspection. It is a figure which shows an example of a functional structure of each unit in a measuring device. 2 is a diagram illustrating an example of a configuration of an adapter 100. FIG. 2 is a diagram illustrating an example of a configuration of an adapter 100. FIG. It is a figure which shows an example of the measurement screen. It is a figure which shows an example of a modification. It is a figure which shows an example of a modification. It is a figure which shows an example of a modification. It is a figure which shows an example of a modification. It is a figure which shows an example of a prior art example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, in the embodiment, a measurement target object is a press sheet metal (made of a metal material), a reference object is a check tool (inspection mold), and a gap between the press sheet metal and the inspection mold is measured. Will be described as an example. Of course, you may make it measure the clearance gap between objects other than this.

(Embodiment 1)
FIG. 1 is a diagram showing an outline of a measuring apparatus according to an embodiment of the present invention.

  The measuring device measures a gap between objects. In the present embodiment, the measuring device measures a gap between the press sheet metal 110 clamped on the inspection mold 120 via a spacer and the inspection mold 120. More specifically, the measuring device measures the distance of the gap along the vertical direction from the surface of the inspection mold 120 to the press sheet metal 110. Here, a case will be described in which a gap of up to 10.0 mm is a measurement target as the gap distance.

  Here, the measuring device is configured to include a sensor unit 10 and a processing unit 30, and these units are connected via a cord 13.

  The sensor unit 10 is grounded to the gap when the gap is measured. The sensor unit 10 includes a support portion 11 and a housing portion 12 as its external configuration. Although details will be described later, a light source and a camera are provided inside the sensor unit 10.

  The casing 12 is provided with a cord 13 and a button 14. The code 13 is used to exchange video signals and power, and the button 14 is used to input a shooting instruction from the user. The arrangement positions of the cords 13 and the buttons 14 are merely examples, and may be provided at any position in the housing unit 12. In addition, the button 14 may be provided as an external button via a code or the like (or wirelessly) instead of on the housing unit 12.

  The support part 11 has a rod-like shape and is configured to extend from the housing part 12 along a predetermined direction. When measuring the gap between the press sheet metal 110 and the inspection mold 120, the grounding part 11a is grounded to the inspection mold 120, and the side surface of the support part 11 is the edge of the press sheet metal 110 ( Grounded at the cut).

  For example, the support portion 11 has a length of 2 cm along the extending direction (arrow C direction), and the housing portion 12 has a length of 7 cm along the longitudinal direction (arrow C direction). And it has a length of 3 cm along the short direction and the width direction. In other words, the sensor unit 10 is realized with a size (and weight) that the user can easily hold with one hand.

  In addition, the dimension of the sensor unit 10 illustrated here is an example to the last, and can be suitably changed according to the shape and size of the object to be measured. As described above, in the present embodiment, since a gap of up to 10.0 mm is a measurement target, the length of the support portion 11 in the extending direction is required to be 1 cm or more. Further, according to the characteristics of the (small) camera mounted on the sensor unit 10 according to the present embodiment, the distance between the camera and the gap can be reduced to 3 to 4 cm, but the focus can be adjusted if the distance is further increased. Out of range and out of focus. For this reason, in the captured image, the change in luminance value between the shadow of the gap and the boundary of the sheet metal cut is not steep, and it is difficult to specify the boundary position in units of pixels. The dimensions are the sizes exemplified above.

In consideration of the dimensions of the sensor unit 10, it is necessary to pay attention to the following points.
1. From the viewpoint of resolution, it is desirable that the camera inside the sensor unit 10 be close to the gap to be measured. This is because the number of pixels per 1 mm gap increases due to the proximity.
2. On the other hand, the proximity of the camera is limited. If they are too close together, the image will be out of focus, and it will be difficult to specify the boundary position where the transition from the shadow area of the sheet metal to the lower end of the sheet metal cut is made on the captured image.
3. From the viewpoint of handling the sensor unit 10, the overall size of the sensor unit 10 is preferably larger than the gap and smaller within the range that can be held by hand. This is because, when it is small, it is easy to avoid contact with an obstacle on the upper surface of the press sheet metal, such as an arm of a clamp that fixes the press sheet metal 110 to the inspection mold 120.
4). Considering sliding adapter mounting (see FIGS. 14 and 15 to be described later), the sensor unit 10 (housing) is preferably long to some extent in the longitudinal direction in which the adapter device is slid.

  The processing unit 30 is realized by, for example, a personal computer or a dedicated device (a device that performs an operation based on a measurement result of a gap) or the like, and is based on a video signal (a plurality of continuous images (frames)) from the sensor unit 10. Performs arithmetic processing and displays measurement results. The processing unit 30 is connected to the sensor unit 10 via the cord 13, receives a video signal from the sensor unit 10 via the cord 13, and supplies power to the sensor unit 10 via the cord 13. Do.

  Here, as shown in FIG. 2, a light source 21 and an imaging device (hereinafter referred to as a camera) 22 are provided inside the sensor unit 10.

  Here, in this embodiment, the case where the position of the camera 22 is fixed with respect to the support part 11 is demonstrated. Although details will be described later, in the present embodiment, in the extending direction (axial direction) of the support portion 11 from the inspection mold 120 on the photographed image taken by the camera 22 to the cut end (the lower end) of the press sheet metal 110. The relationship between the distance along the line and the actual distance is held in a conversion table (see FIG. 4 described later). Therefore, if the positional relationship between the support unit 11 and the camera 22 changes, the conversion table must be recreated. Therefore, if the positional relationship between the camera 22 and the support unit 11 is fixed, the number of necessary conversion table creations can be minimized.

  On the other hand, the positional relationship between the camera 22 and the light source 21 can be changed independently of the information held in the conversion table. In order to be able to identify the difference in luminance value at the boundary between the shadow of the gap and the cut edge (the lower end) of the press sheet metal, the light source 21 requires the cut area of the press sheet metal 110 because the shadow area s of the gap is sufficiently dark. What is necessary is just to provide in the position and direction which can illuminate sufficiently brightly. For example, the light source 21 may be installed so as to irradiate the area directly toward the cut surface of the press sheet metal 110. Alternatively, in order to keep the above illumination conditions stable even when the external light increases or decreases, the light source 21 irradiates the entire field of view of the camera 22, and the amount of light incident on the camera 22 is controlled by the light emitted by the light source 21. A light source 21 may be provided. In this case, the indirect light reflected by the inspection mold 120 brightly illuminates the sheet metal cut.

  When measuring the gap between the press sheet metal 110 and the inspection die 120, the grounding portion 11a of the support portion 11 is grounded with respect to the inspection die 120, and along the extending direction of the support portion 11 (arrow C direction). The side face is grounded to the edge of the press sheet metal 110.

  The support part 11 needs to stand upright with respect to the test | inspection type | mold 120 (surface). When the support portion 11 having the form shown in FIG. 1 or the like is adopted, the support portion 11 is generally erected vertically by the user's eyes, but the ground contact area of the ground contact portion 11a of the support portion 11 may be increased. In addition, by attaching an adapter device (see FIGS. 14 and 15 to be described later) to the sensor unit 10, it is possible to make it easy to take the vertical by tactile sense. In addition, the necessity to take the vertical by means such as visual sense or tactile sensation which is not provided in the measuring means itself is the same when measuring the gap with a conventional taper gauge.

  Here, the user fixes the sensor unit 10 so that the support portion 11 is perpendicular to the inspection mold 120, and in this state, presses the button 14 provided on the sensor unit 10. Then, light is emitted from the light source 21, and the irradiation light irradiates a region including the cut surface of the press sheet metal 110 and the inspection mold 120. In addition, although it is desirable from the viewpoint of power saving when the light source 21 is turned on only when the button 14 is pressed, it is not limited thereto. For example, the camera 22 may always take a picture while the light source 21 is always turned on, and the button 14 may be used purely as a measurement trigger.

  Here, in the inspection die 120, the region located below the press sheet metal 110 is a shadow region (range s in the figure) because the irradiation light does not reach most of the region. Therefore, on the photographed image photographed by the camera 22, the contrast is increased between the lower end of the cut edge of the press sheet metal 110 and the shadow area, and the lower edge of the press sheet metal 110 is easily detected. Therefore, in this embodiment, the gap between the press sheet metal 110 and the inspection mold 120 is measured using this principle.

  This measurement principle will be described in detail. FIG. 3 is a diagram showing an example of a screen (measurement screen) 50 displayed on the display (display unit 32 described later) of the processing unit 30 shown in FIG.

  The measurement screen 50 is provided with a display area 40, a luminance value display area 51, and operation areas 52 to 59. In the display area 40, an image captured by the camera 22 of the sensor unit 10 described above is displayed. In this case, an image photographed by the camera 22 at the time of measurement shown in FIG. Such an image display is not indispensable for the measurement of the gap and the calibration. In this embodiment, a case where such an image is displayed will be described for demonstration and explanation of operation.

  In the display area 40, an inspection mold area 42, a shadow area 43, a sheet metal lower end area 44, a sheet metal upper end area 45, a sheet metal area 46, a gap area 47, and a support area 48 are displayed. . In addition, the display area 40 also displays a first line 61, a second line 62, a luminance line 63, a contact line 64, and the like. The sheet metal lower end region 44 corresponds to the lower end of the cut end of the press sheet metal 110 shown in FIG. 2, and the sheet metal upper end region 45 corresponds to the upper end of the cut end of the press sheet metal 110 shown in FIG. The contact line 64 is displayed in an area where the support part 11 is shown on the captured image. The shadow area 43 corresponds to the shadow area s shown in FIG. The reason why the shadow area 43 and the gap area 47 do not match is that the area immediately below the cut edge of the press sheet metal 110 does not become the shadow area s as shown in FIG.

  When a camera having a larger number of horizontal pixels than the number of vertical pixels (normal camera) is used as the camera 22, the image is taken so that the extending direction of the support portion 11 matches the horizontal direction on the camera photographed image. Is advantageous in terms of resolution. In the present embodiment, in consideration of this point, the camera is rotated 90 degrees counterclockwise, the left side in the display area 40 is down (inspection mold 120 side), and the right side is up (press sheet metal 110 side). It is trying to become.

  In the luminance value display area 51, a waveform of luminance values along the luminance line 63 in the display area 40 is shown. In the luminance value display area 51, for example, after removing noise by inter-frame median filtering for temporally continuous images (for example, 7 frames) captured by the camera 22, the luminance line 63 is centered. A value obtained by averaging the plurality of lines (for example, 5 lines) is displayed.

  Referring to the luminance value of the luminance value display region 51, the luminance value corresponding to the boundary between the sheet metal lower end region 44 and the shadow region 43 causes a sudden transition from a valley (dark portion) to a mountain (bright portion). . Therefore, the lower end of the cut end of the press sheet metal 110 can be detected by detecting such a sudden change in luminance value.

  When the luminance value of the luminance value display area 51 is referred to, a sudden change in the luminance value occurs at the boundary between the inspection mold area 42 and the shadow area 43. Here, with respect to the waveform of the luminance value exemplified in the luminance value display area 51, when the X axis is taken from the left to the right toward the area, the inspection mold area 42 against the increase of X. The waveform from to the shadow region 43 draws a decreasing curve. On the other hand, the waveform from the shadow area 43 to the sheet metal lower end area 44 draws a steep increase curve. Such a difference occurs because, when the luminance line 63 is traced from the inspection mold 120 toward the press sheet metal 110, the former is entering the shadow area and the latter is escaping from the shadow area. is there. From this, it can be mechanically determined that the boundary between the inspection die region 42 and the shadow region 43 is not the lower end of the cut end of the press sheet metal 110.

  Furthermore, if the increase curve is not steep even if it is an increase curve, or if the increase amount is small even if it is an increase curve and steep (if the height of the peak immediately after the increase is small relative to the valley bottom before the increase), then the press sheet metal 110. It can be mechanically determined that it is not the lower end of the cut. That is, when ΔY / ΔX is sufficiently large when the increment of the luminance value per X increment ΔX of an appropriate size is ΔY, there is a high possibility that it is the lower end of the cut end of the press sheet metal 110. Otherwise, the possibility of being the lower end of the cut end of the press sheet metal 110 is low. In the present embodiment, a value serving as a determination criterion is input (by the user) to the threshold value item in the edge detection parameter adjustment field 54 to suppress erroneous detection of the lower end of the cut end of the press sheet metal 110. Of course, other methods may be used to suppress erroneous detection of the lower end of the cut end of the press sheet metal 110.

  Next, the operation areas 52 to 59 will be described. The operation area includes a gap size display field 52, a measurement line position adjustment field 53, an edge detection parameter adjustment field 54, and a check for selecting whether or not to display an image on the display area 40. A box 55, a calibration button 56 for instructing execution of calibration, a cursor position adjustment field 57, a save button 58 for instructing saving of a conversion table, and a cancel button 59 for instructing cancellation of processing are provided. .

  In the gap size display field 52, the size of the gap area 47 (along the extending direction of the support portion 11) (that is, the gap distance) is displayed in units of mm. The number of pixels from the first line 61 to the second line 62 is also displayed. Note that the display of the number of pixels is not necessarily performed, and is shown here for the purpose of demonstration and explanation of operation.

  In the measurement line position adjustment column 53, items for adjusting the positions of the luminance line 63 and the contact line 64 are provided as basic items and contact position items, respectively. In this case, the position of these lines is adjusted by adjusting the Y coordinate value.

  In the edge detection parameter adjustment field 54, input items for inputting conditions for detecting the boundary between the sheet metal lower end region 44 and the shadow region 43 as edges are provided as threshold items, frame number items, and line number items. Yes. In the threshold value item, a threshold value (in this case, 20) for determining whether or not it is the lower end of the cut edge of the press sheet metal 110 is set, and when there is a change in luminance value exceeding the threshold value set here. , The boundary is detected as an edge.

  In the present embodiment, two stages of filtering for adjusting the waveform of the luminance value are performed as pre-processing for this determination. More specifically, the first filtering for the purpose of noise removal is performed using the image of the latest past m frames, and then the stabilization is performed using the luminance of the n lines centered on the luminance line 63. The second filtering is performed. In this way, measures are taken to ensure a margin for erroneous detection. Here, m and n are determined by (user) input to the frame number item (in this case, 7 frames) and the line number item (in this case, 5 lines) in the edge detection parameter adjustment field 54, respectively. It is done. In addition to the above, in order to increase the determination accuracy, it is only necessary to appropriately take measures according to characteristics of the camera 22 to be used and the transmission path of the video signal.

  In the cursor position display column 57, items for displaying the cursor position are provided as first to fourth line items, respectively. In the present embodiment, the first line 61 and the second line 62 are displayed on the display area 40, and their horizontal positions are displayed numerically in the first line item and the second line item, respectively. The In addition, adjustment by manual input of these numerical values is unnecessary. In this case, the third line item and the fourth line item are not used.

  The first to fourth lines are displayed in the vertical direction (the direction orthogonal to the luminance line 63) on the display area 40, and in the items provided corresponding to the lines, the X coordinate value is confirmed. Yes. The first line 61 is displayed at a predetermined position (reference position) on the inspection mold area 42, and this position is determined by calibration described later. The second line 62 is displayed at the boundary position between the sheet metal lower end region 44 and the shadow region 43 detected based on the luminance value.

  In the present embodiment, the case where the cursor position display column 57 has only the function of displaying the X coordinate values of the first to fourth lines has been described, but the present invention is not limited to this. . For example, each item (first to fourth line items) provided in the cursor position display field 57 may be realized as an input / output item so that the value displayed in the cursor position display field 57 can be adjusted. .

  Here, the processing unit 30 holds a conversion table 130 shown in FIG. Note that the information defined in the table 130 is set by calibration described later.

  In the conversion table 130, the distance in pixel units on the captured image (captured by the camera 22) from the inspection mold 120 (more specifically, the reference position) on the captured image to each position is set to the actual distance. Information for conversion is defined. Such information is held because the distance on the captured image and the actual distance are not equal for each position along the X direction on the captured image. Moreover, it is because a non-linear correspondence occurs between the two.

  This point will be further described. In the captured image, there is distortion due to one-point perspective transformation of the imaging system (camera 22) (and lens distortion is also superimposed). For this reason, a non-linear correspondence occurs between the distance measured from the captured image and the actual distance. Note that the curve that draws the monotonically increasing curve shown in FIG. 4 is a collection of many examples of pairs (X, D), where X is the position on the captured image and D is the corresponding physical distance (height). It can be obtained by processing, or by deriving an approximate curve from a plurality of representative examples of the set (X, D). In the present embodiment, the third-order polynomial approximation is obtained according to the latter method.

  Here, for example, consider the case where the boundary between the sheet metal lower end region 44 and the shadow region 43 is detected with the X coordinate value: 341. In this case, the actual gap distance is 0.9 mm because the Y coordinate value corresponding to the X coordinate value is 0.9. In this case, the reference position (first line 61 shown in FIG. 3) is X coordinate value: 324.

  Next, calibration of the sensor unit 10 will be described with reference to FIGS. 5 (a) and 5 (b). The calibration is performed for the purpose of creating the contents of the conversion table 130.

  The calibration is performed in a state where the sensor unit 10 is stored in a case (calibration jig) 70 as shown in FIG. The case 70 is configured to store at least the support portion 11 of the sensor unit 10.

  Here, as shown in FIG. 5B, adjustment patterns 74 (74a, 74b) are formed on the side surface 73 and the bottom surface 72 inside the case. The adjustment pattern 74 (74a, 74b) includes, for example, a plurality of parallel lines (adjustment lines), and the plurality of adjustment lines are formed, for example, at equal intervals of a 1 mm period. The adjustment pattern 74a formed on the side surface 73 and the adjustment pattern 74b formed on the bottom surface 72 are formed using, for example, adjustment lines of different colors. Here, a case where the adjustment pattern 74b is also formed on the bottom surface 72 is described as an example, but in the first embodiment, the adjustment pattern 74b on the bottom surface 72 is not essential.

  Calibration is performed by photographing the adjustment pattern 74 described above with the camera 22. More specifically, when the sensor unit 10 is stored in the case 70, the grounding portion 11a of the support portion 11 is grounded to the bottom surface (first surface) 72 inside the case, and the extending direction of the support portion 11 is set. The surface along the line contacts the side surface (second surface) 73 inside the case. Calibration is performed in this state. That is, since calibration is performed in the state stored in the case 70, it is difficult to be affected by disturbance of illumination light or the like during calibration.

  Calibration is started when the calibration button 56 is pressed by the user after the sensor unit 10 is stored in the case 70 and the measurement screen 50 shown in FIG. 3 is displayed.

  FIG. 6 is a diagram showing an example of a screen (calibration screen) 80 displayed on the display (display unit 32 described later) of the processing unit 30 shown in FIG. The calibration screen 80 has basically the same screen configuration as the measurement screen 50 described with reference to FIG. 3, and the image displayed in the display area 40 is different. Therefore, description of each part of the screen is omitted here.

  In the display area 40, an image obtained by photographing the inside of the case with the camera 22 is displayed. In this case, a bottom area 81 and a side area 82 are displayed in the display area 40. As described above, in the first embodiment, since the calibration result of the bottom surface area 81 is not necessary, the display in the display area 40 corresponding to the bottom surface area 81 and the display of the luminance value display area 51 may be omitted.

  Here, the adjustment pattern 74 formed on the side surface 73 and the bottom surface 72 inside the case 70 is detected based on the luminance value measured along the luminance line 63. That is, referring to the luminance value of the luminance value display area 51, the luminance value detected from the adjustment line is a valley, and the adjustment line can be detected by detecting this.

  Here, in the measurement screen 50 shown in FIG. 3 described above, the lower end of the cut edge of the press sheet metal 110 is detected with a sharp increase in the luminance value, whereas in the calibration screen 80, the depth that simply exceeds the threshold value is detected. A plurality of adjustment lines are detected at the same time with the position of a brightness valley having a certain thickness. By doing this, instead of making measurements repeatedly while making various heights using actual cuts of the press sheet metal 110, measurement of adjustment patterns drawn to various heights with a single line such as black is performed. Calibration can be realized by performing it once. However, when changing the mode of the adjustment pattern, it may be possible to change to another appropriate detection method.

  Here, the processing unit 30 updates (creates) the conversion table described in FIG. 4 based on the interval between the adjustment lines detected from the captured image and the actual interval between the adjustment lines (in this case, 1 mm). Including).

  Further, by the calibration process, in the processing unit 30, the boundary between the bottom surface region 81 and the side surface region 82 (the start point of the adjustment pattern 74a formed on the side surface 73) is set to the reference position 65 (the first line 61 shown in FIG. 3). Corresponding).

  Here, an example of a functional configuration of each unit in the measurement apparatus illustrated in FIG. 1 will be described with reference to FIG.

  The sensor unit 10 includes a button 14, a light source 21, and a camera 22 as a functional configuration. Since the button 14, the light source 21, and the camera 22 have been described with reference to FIG. 2, description thereof will be omitted.

  The processing unit 30 includes an operation unit 31, a display unit 32, a power supply unit 33, a control unit 34, an IF (Interface) unit 35, and a storage unit 36 as functional configurations.

  The operation unit 31 is composed of, for example, a keyboard and a mouse, and inputs an instruction from the user into the processing unit. The display unit 32 is composed of, for example, a display and displays various information.

  The power supply unit 33 supplies power to each component of the processing unit 30 and also supplies power to the sensor unit 10.

  The control unit 34 includes, for example, a memory such as a CPU, a ROM (Read Only Memory), and a RAM (Random Access Memor), and controls the processing in the processing unit 30 in an integrated manner. Various processes in the processing unit 30 are performed by a CPU (Central Processing Unit) reading and executing a program stored in the storage unit 36 using a memory as a work area.

  The IF unit 35 includes, for example, a network card, a USB (Universal Serial Bus), an external communication interface, and the like, and a communication interface that controls communication between the processing unit 30 and another device (in this case, a sensor unit). Function as. The processing unit 30 receives video data from the sensor unit 10 via the IF unit 35.

  The storage unit 36 is realized by an HDD (Hard Disk Drive) or the like and stores various data. In the storage unit 36, for example, a conversion table 130 is held in addition to various programs such as an operating system and applications.

  Here, the control unit 34 includes an image acquisition unit 140, an image processing unit 141, a gap calculation unit 145, a calibration processing unit 146, and a display processing unit 147 as functional configurations. . Note that these configurations on the control unit 34 are realized, for example, when the CPU reads and executes a program stored in the storage unit 36 using the memory as a work area.

  The image acquisition unit 140 acquires an image (captured image) from the video signal (a plurality of continuous images) in response to a shooting instruction from the sensor unit 10.

  The image processing unit 141 has a function of performing various image processing on the captured image acquired by the image acquisition unit 140, and includes a luminance value acquisition unit 142, a boundary detection unit 143, and an adjustment pattern detection unit 144. Configured.

  The luminance value acquisition unit 142 acquires a luminance value along the luminance line 63 from the captured image.

  The boundary detection unit 143 detects a boundary (corresponding to the second line 62 shown in FIG. 3) between the sheet metal lower end region 44 and the shadow region 43 shown in FIG. This boundary detection is performed based on information (threshold value, number of frames, number of lines) set in the edge detection parameter adjustment field 54 of FIG.

  The adjustment pattern detection unit 144 detects the adjustment pattern 74 (adjustment line) based on the luminance value acquired by the luminance value acquisition unit 142 during calibration.

  The gap calculation unit 145 calculates the (actual) gap distance based on the information detected by the boundary detection unit 143. This calculation is performed using the conversion table 130 held in the storage unit 36.

  The calibration processing unit 146 performs calibration based on the adjustment pattern 74 (adjustment line) detected by the adjustment pattern detection unit 144. Thereby, the conversion table 130 and the reference position 65 are updated.

  The display processing unit 147 displays various information on the display unit 32. For example, the display on the display unit 32 such as the measurement screen shown in FIG. 3 or the calibration screen shown in FIG. 6 is controlled.

  Next, an example of the processing flow of the measurement apparatus shown in FIG. 1 will be described with reference to FIGS. First, with reference to FIG. 8, a gap between objects (here, a gap between the press sheet metal 110 clamped on the inspection mold (inspection tool) 120 via a spacer and the inspection mold 120) is measured. The flow of processing at that time will be described.

  This process is performed by the user in a state where the grounding portion 11a of the support portion 11 is grounded with respect to the inspection mold 120 and the surface along the extending direction of the support portion 11 is grounded to the cut surface of the press sheet metal 110. The operation starts when the button 14 provided on the unit 10 is pressed.

  As the button 14 is pressed, the processing unit 30 receives a shooting instruction from the sensor unit 10 (YES in S101). Then, the processing unit 30 acquires the video signal at the time of pressing the button as a captured image in the image acquisition unit 140 (S102). Then, the luminance value acquisition unit 142 calculates and acquires the luminance value on the captured image along the luminance line 63 (S103).

  When the luminance value is acquired, the processing unit 30 detects the boundary between the lower end region 44 and the shadow region 43 of the cut end of the press sheet metal 110 based on the luminance value in the boundary detection unit 143 (S104). As described above, this detection is performed by detecting a luminance value having a change exceeding a predetermined threshold.

  Subsequently, in the gap calculation unit 145, the processing unit 30 calculates the gap distance based on the boundary detected in the process of S104 and the conversion table 130 (S105). More specifically, referring to the conversion table 130 based on the position of the boundary on the captured image acquired in the process of S102, the distance from the reference position to the boundary on the captured image is converted into the actual gap distance. .

  Finally, the processing unit 30 causes the display processing unit 147 to display the gap distance (calculation result) calculated in the process of S105 on the measurement screen described with reference to FIG. 3 (S106).

  Next, the flow of processing when performing calibration will be described with reference to FIG.

  This process starts when the user presses the calibration button 56 from the measurement screen 50 shown in FIG. 3 while the sensor unit 10 is stored in the case 70.

  When the calibration button 56 is pressed (ie, calibration start instruction) (YES in S201), the processing unit 30 acquires the video signal at the time of pressing the button as a captured image in the image acquisition unit 140 (S202). . Then, the luminance value acquisition unit 142 calculates and acquires the luminance value on the captured image along the luminance line 63 (S203).

  When the luminance value is acquired, the processing unit 30 detects the adjustment pattern 74 (adjustment line) from the captured image acquired in the process of S202 in the adjustment pattern detection unit 144 (S204). As described above, this detection is performed by detecting a valley of luminance having a depth exceeding a predetermined threshold.

  Subsequently, in the calibration processing unit 146, the processing unit 30 updates the conversion table 130 based on the position of the adjustment line on the captured image in units of pixels and the actual height from the bottom surface 72 of the adjustment line (S205). ). More specifically, the processing unit 30 holds the interval between actual adjustment lines in advance, and for each individual adjustment line based on the interval information and the number of adjustment lines counted from the bottom surface 72. The actual height D from the bottom surface 72 is obtained. Then, the conversion table 130 is updated by storing a set (X, D) of the adjustment line detected from the captured image with the position X in pixel units for each adjustment line and performing polynomial approximation. Further, in the calibration processing unit 146, the processing unit 30 updates the reference position 65 on the basis of the position in pixel units of the adjustment line on the captured image whose height D = 0 (S206).

  As described above, according to the present embodiment, the boundary between the lower end region 44 and the shadow region 43 of the cut end of the press sheet metal 110 is detected from the photographed image obtained by photographing the gap between the press sheet metal 110 and the inspection mold 120. Then, the gap is measured based on the detected boundary. Therefore, the gap can be measured regardless of the shape of the gap between the objects.

  That is, there is no need to insert a gap gauge between objects, and the gap can be measured simply by grounding the sensor unit 10 to the object to be measured, so the gap (edge, hole) has no depth. Even if it exists, the gap can be measured. In addition, since it is not necessary to read with a naked eye a scale such as a gap gauge inserted between objects, the measurement result of the gap can be read accurately.

  Furthermore, the gap can be measured simply by grounding the sensor unit 10 to the object to be measured, and the measurement result can be easily read, so that the work time required for the measurement of the gap can be shortened. In addition, since the distance of the gap at the position where the support portion 11 is applied can be measured, the user can measure the distance of the gap with a sense of applying a ruler.

(Embodiment 2)
Next, Embodiment 2 will be described. In the second embodiment, a case will be described in which a scale is formed on the support portion 11 along the extending direction of the support portion 11 (arrow C direction).

  As shown in FIG. 10, scales are formed at equal intervals on the support portion 11 of the sensor unit 10 according to the second embodiment. In addition, the support part 11 may be comprised with the transparent (light transmissive) member, for example.

  In the second embodiment, the grounding part 11a of the support part 11 is grounded to the inspection mold 120, and the gap is measured in a state where the side surface of the support part 11 on which the scale is formed is grounded to the cut surface of the press sheet metal 110. To do.

  In the case of such a configuration, the actual gap distance can be measured based on the boundary between the lower end of the cut end of the press sheet metal 110 and the shadow area and the scale formed on the support portion 11. In the second embodiment, the conversion table 130 is not used.

The processing unit 30 measures the actual gap distance based on the scale interval information and the boundary and scale information on the captured image. More specifically, if the intersection of the lower end of the cut of the press sheet metal 110 detected from the photographed image and the support portion 11 is between the nth and n + 1th positions from the bottom of the scale formed on the support portion 11. The height of the lower end of the cut of the press sheet metal 110 with respect to the inspection mold 120 is
a (n−1) + b mm to a · n + b mm
Between.

  Here, b indicates the height (unit: mm) of the lowest scale among the scales formed on the support portion 11, and a indicates the cycle (unit: mm) of the scale. In order to obtain a resolution exceeding the graduation period a mm, the lower end of the cut end of the press sheet metal 110 is nth from the bottom on the photographed image as if a human being measured the length with a ruler to 1/10 of the minimum graduation. If it is between n + 1 and n + 1, the position of the lower end of the cut located between the scales may be obtained by linear interpolation of the height corresponding to these two scales.

  Here, an example of the processing flow of the measurement apparatus according to the second embodiment will be described with reference to FIG. Here, the flow of processing when measuring the gap between objects (here, the gap between the press sheet metal 110 clamped to the inspection mold (checking tool) 120 via the spacer and the inspection mold 120) is performed. Will be described.

  Also in the second embodiment, the same processing as S101 to S104 of FIG. 8 described in the first embodiment is performed (S301 to S304). Thereby, the boundary between the lower end region 44 and the shadow region 43 of the cut end of the press sheet metal 110 is detected.

  When the detection of the boundary is completed, the processing unit 30 causes the image processing unit 141 to acquire a region including the scale of the support unit 11 in the captured image acquired in the process of S302 (S304). The region including the scale of the support unit 11 may be acquired based on pattern recognition using the image pattern by holding an image pattern including the scale of the support unit 11 in advance. May be acquired based on a user instruction for designating the region from the measurement screen shown in FIG. In addition, any method may be used as long as such a region can be acquired.

  Subsequently, in the gap calculation unit 145, the processing unit 30 calculates the gap distance based on the boundary detected in the process of S304 and the area information acquired in the process of S305 (S306). More specifically, the distance of the gap is calculated based on the scale information of the support portion 11 along the gap. For example, if the actual interval between the scales is 1 mm and the scale value corresponding to the boundary on the captured image is two scales, the actual gap distance is 2 mm.

  Finally, the processing unit 30 causes the display processing unit 147 to display the gap distance (calculation result) calculated in the process of S306 on the measurement screen described with reference to FIG. 3 (S307).

  As described above, according to the second embodiment, similarly to the first embodiment described above, the gap between the objects can be measured regardless of the shape of the gap between the objects. Also, calibration is not necessary.

(Embodiment 3)
Next, Embodiment 3 will be described. In the third embodiment, in addition to the measurement of the gap between the press sheet metal 110 and the inspection mold 120 along the vertical direction (with respect to the surface of the inspection mold 120), the press sheet metal 110 and the inspection mold 120 A case where the distance along the horizontal direction (that is, the deviation along the surface of the inspection mold 120) is measured will be described.

  Here, as shown in FIG. 12A, a design line 91 is formed on the inspection mold 120 along the outer shape of the press sheet metal 110 and the edge of the hole. The design line 91 represents the design shape of the press sheet metal 110 itself. A trim line 92 is formed outside the design shape with a predetermined distance relationship (for example, 3 mm) along the design line 91.

  In the third embodiment, the horizontal distance from the design line 91 to the edge of the press sheet metal 110 is indirectly measured by measuring the distance along the horizontal direction between the edge (cut) of the press sheet metal 110 and the trim line 92. Measure the deviation along the direction.

  The reason why the distance from the design line 91 is not directly measured is that when the edge of the press sheet metal 110 protrudes outside the design line 91, the design line 91 itself cannot be directly seen from above. Even in the conventional technique, in such a case, indirect measurement via the trim line 92 is unavoidable.

  At the time of measurement, as shown in FIG. 12B (similar to the first embodiment described above), the grounding portion 11a of the support portion 11 is grounded to the inspection mold 120, and the extending direction of the support portion 11 (arrow) The surface along the (C direction) is grounded to the cut surface of the press sheet metal 110. In this state, the user presses the button 14 provided on the sensor unit 10.

  Thereafter, the boundary between the lower end region 44 and the shadow region 43 of the cut end of the press sheet metal 110 is detected as in the first embodiment described above. At this time, the processing unit 30 also detects the trim line 92 in the image processing unit 141. For example, the trim line 92 may be detected based on the valley of the luminance value in the same manner as when the adjustment line is detected in the calibration.

  Then, the gap distance is calculated based on the detected boundary as in the first embodiment, and the distance from the reference position 65 to the trim line 92 is also calculated.

When this calculation result is converted into the distance from the design line 91 to the reference position 65, the following equation may be used. The following formula shows a case where the distance relationship between the design line 91 and the trim line 92 is 3 mm.
(Distance from design line 91 to reference position 65)
= 3 mm-(distance from reference position 65 to trim line 92)

  According to the above description, it is understood that only the trim line 92 among the design line 91 and the trim line 92 needs to be detected from the captured image by image processing.

  Here, when the edge of the press sheet metal 110 is inside the design line 91, both the design line 91 and the trim line 92 are included in the field of view of the camera 22. At this time, as a technique for preventing the mistake of these lines, for example, the trim lines 92 may be detected by image processing (detection or exclusion of a specific color) by drawing both in advance in different colors. In addition, when the line color cannot be changed later with an existing inspection mold or the like, the luminance pattern of the line starts from the outer edge of the press sheet metal 110 sufficiently toward the press sheet metal 110 from the start point. And the first found line may be regarded as the trim line 92.

  Next, an example of a functional configuration of the measurement apparatus according to the third embodiment will be described with reference to FIG.

  In the third embodiment, a trim line detection unit 148 that detects the trim line 92 based on the luminance value on the captured image is newly provided in the image processing unit 141. Further, a horizontal distance calculation unit 149 that calculates a distance from the reference position 65 to the trim line 92 is newly provided in the control unit 34.

  Here, a method for calculating the horizontal distance will be briefly described. As described above with reference to FIG. 5, the adjustment pattern 74 b (a plurality of equally spaced adjustment lines) is also formed on the bottom surface 72 of the case 70, and therefore, along the horizontal direction on the inspection mold area 42 during calibration. You can also adjust the distance.

  Since the adjustment pattern of the bottom surface 72 of the case 70 is formed using an adjustment line having a color different from that of the adjustment pattern of the side surface 73, the adjustment pattern formed on the bottom surface 72 and the side surface 73 on the photographed image is They can be distinguished by performing color-based filtering. Further, the adjustment pattern may be formed only on the side surface 73 without forming any adjustment pattern on the bottom surface 72 of the case 70 to prevent confusion of the adjustment pattern between the bottom surface 72 and the side surface 73. In this case, the case 70 is configured to be rotatable so that the side surface 73 and the bottom surface 72 are interchanged, and the adjustment pattern formed on the side surface 73 is used as the adjustment pattern for the bottom surface 72 when adjusting the distance along the horizontal direction. You can do that.

  Here, in the processing unit 30, it is possible to acquire the correspondence between the distance on the inspection mold area 42 of the captured image captured by the sensor unit 10 and the actual distance. This correspondence information may be defined in a conversion table prepared separately from the conversion table 130 for measuring the gap. Accordingly, the distance from the reference position 65 of the inspection mold area 42 to the trim line 92 can be calculated. Furthermore, if the actual distance between the trim line 92 and the design line 91 is held in advance, the actual distance is compared with the measured distance, so that the press sheet metal 110 and the inspection line are compared. Deviation along the horizontal direction from the mold 120 can also be measured.

  As described above, according to the third embodiment, in addition to the configuration of the first embodiment, the distance between the press sheet metal 110 and the inspection mold 120 along the horizontal direction can be measured.

(Embodiment 4)
Next, Embodiment 4 will be described. In Embodiment 4, the structure which provided the adapter 100 with respect to the sensor unit 10 is demonstrated. Here, the configuration of the adapter 100 will be described with two examples.

  First, the configuration of the first adapter 100 will be described with reference to FIG. 14A shows a schematic diagram of the sensor unit 10 to which the adapter 100 is attached (a diagram viewed from the direction of arrow A in FIG. 1 and a diagram viewed from the direction of arrow B in FIG. 1). FIG. 14B shows a schematic diagram of the sensor unit 10 when the adapter 100 is slid to the press sheet metal 110 (viewed from the direction of arrow A in FIG. 1).

  The adapter 100 serves to stabilize the measurement posture of the sensor unit 10 when the sensor unit 10 measures the gap between the press sheet metal 110 and the inspection mold 120. That is, the support part 11 is stably fixed to the inspection mold 120 so as to be vertical.

  The adapter 100 is detachably attached to the sensor unit 10 (housing unit 12), and is configured to be slidable (movable) along the longitudinal direction (arrow C direction) of the housing unit 12 of the sensor unit 10.

  When measuring the gap, the adapter 100 is slid toward the press sheet metal 110 as shown in FIG. As a result, the adapter grounding unit 101 is grounded to the press sheet metal 110.

  Here, the adapter grounding part 101 is composed of, for example, a magnet (neodymium), and when the adapter grounding part 101 is grounded to the press sheet metal 110, the grounding part 101 and the press sheet metal 110 are attracted by a magnetic force. The support unit 11 of the sensor unit 10 is also provided with a magnet (neodymium) 11b. Therefore, when measuring the gap, since the measurement can be performed in a state where two points are grounded by the magnet 11b provided in the support portion 11 and the magnet provided in the adapter grounding portion 101, the measurement can be performed in a more stable state. Become.

  In addition, although the case where the adapter grounding part 101 was comprised with the magnet was demonstrated in the structure mentioned above, it does not necessarily need to be comprised with a magnet. The adapter grounding part 101 may be comprised with the member which used rubber | gum etc. as a material, for example.

  Moreover, although the case where a magnet is provided also to the support part 11 was demonstrated, it is not necessary to necessarily provide a magnet with respect to the support part 11. FIG.

  Furthermore, the predetermined surface of the adapter 100 indicated by reference numeral 103 in FIG. 14B may be opaque (impermeable to illumination light). In this case, since the influence of disturbance due to illumination light or the like from the direction of arrow D in FIG. 14B can be suppressed, the gap can be measured with higher accuracy.

  Next, the configuration of the second adapter 100 will be described with reference to FIG. FIG. 15A shows a schematic diagram of the sensor unit 10 to which the adapter 100 is attached (viewed from the direction of arrow A in FIG. 1). FIG. 15B shows a schematic diagram of the sensor unit 10 when the adapter 100 is slid to the press sheet metal 110 (viewed from the direction of arrow A in FIG. 1).

  The adapter 100 shown in FIG. 15 is detachably attached to the sensor unit 10 (housing part 12) in the same manner as FIG. 14 described above, and extends along the longitudinal direction (arrow C direction) of the housing part 12 of the sensor unit 10. And slidable.

  When measuring the gap, the adapter 100 is slid in the direction of arrow C as shown in FIG. As a result, the adapter grounding unit 104 is grounded to the inspection mold 120. That is, when the adapter 100 is slid to the press sheet metal 110 when measuring the gap, the adapter grounding portion 101 is in contact with the press sheet metal 110 in the adapter 100 shown in FIG. 14, but the adapter shown in FIG. In 100, the adapter grounding unit 104 is in a state of grounding to the inspection mold 120. Even when the adapter 100 shown in FIG. 15 is used, since the measurement can be performed with two points in contact with the ground as in the case of using the adapter 100 shown in FIG. 14, the measurement can be performed in a more stable state. It will be.

  In addition, although the case where a magnet is provided also to the support part 11 of the adapter 100 shown in FIG. 15 was demonstrated, it is not necessary to necessarily provide a magnet with respect to the support part 11. FIG.

  Moreover, the adapter grounding part 104 of the adapter 100 shown in FIG. 15 may be comprised with the member which used rubber | gum etc. as a material, for example. Furthermore, also in the adapter 100 shown in FIG. 15, the predetermined surface of the adapter 100 indicated by reference numeral 103 in FIG. 15B may be opaque (impermeable to illumination light). Also in this case, since the influence of disturbance due to illumination light or the like from the direction of arrow D in FIG. 15B can be suppressed, the gap can be measured with higher accuracy.

  Moreover, you may combine the structure demonstrated using FIG.14 and FIG.15. That is, the adapter 100 may be configured to include both the adapter grounding unit 101 and the adapter grounding unit 104.

  As described above, according to the fourth embodiment, since the measurement can be performed in a stable state when the gap is measured, the gap can be measured with higher accuracy.

(Embodiment 5)
Next, Embodiment 5 will be described. Here, there are cases where the distance of the gap along the contact line 64 cannot be directly measured from the captured image captured by the camera 22 due to the support unit 11 blocking the visual field of the camera 22. Therefore, in the fifth embodiment, a method for indirectly measuring the distance of the gap along the contact line 64 will be described.

  FIG. 16 is a diagram illustrating an example of the measurement screen 50. The measurement screen shown in FIG. 16 is the same as the measurement screen of FIG. 3 describing the first embodiment, and a detailed description of the screen configuration is omitted.

  Here, a plurality of (three) luminance lines (63a, 63b, 63c) are displayed in the display area 40. It is assumed that the above-described conversion table 130 is also provided in advance corresponding to each of a plurality of (three) luminance lines (63a, 63b, 63c). That is, in the fifth embodiment, the luminance line and the conversion table are previously provided as a pair.

  Here, the luminance lines 63a, 63b and 63c are arranged on both sides of the contact line 64 along the vertical direction. Then, in the same manner as in the case of the luminance line 63 in the first embodiment, calibration is performed for each pair of the luminance line and the conversion table, and the contents of the conversion table are determined.

  In this way, the lower end position of the press sheet metal 110 can be detected using each of the three lines near the contact line 64 independently, and the distance between the gaps, that is, the physical height of the lower end of the press sheet metal with respect to the surface of the inspection mold 120 is detected. Three points of H can be acquired.

  The Y coordinate on the photographed image at the lower end position of the press sheet metal 110 is given as the vertical position of the luminance lines 63a to 63c. As a result, three samples of Y and H (Y, H) are obtained, and if they are approximated by a second-order polynomial, a function H (Y) of Y is obtained. If the Y coordinate of the contact line 64 is given to this H (Y), the height of the gap in the contact line 64 is interpolated and calculated.

  As described above, according to the fifth embodiment, in addition to the effects of the first embodiment, positioning at the time of measuring the distance of the gap can be performed quickly and the measurement accuracy can be improved.

  The above is an example of a typical embodiment of the present invention, but the present invention is not limited to the embodiment described above and shown in the drawings, and can be appropriately modified and implemented without departing from the scope of the present invention. . Hereinafter, some modifications will be described.

(Modification 1)
As shown in FIG. 17A, the sensor unit 10 may be further provided with a power supply unit 23, a processing unit 24, and a display unit 25. The power supply unit 23 supplies power to each component of the sensor unit 10. The processing unit 24 performs various calculations. The processing unit (including the CPU, ROM, and RAM) 24 implements the configuration provided in the control unit 34 described with reference to FIG. The display unit 25 displays the measurement result of the gap between objects.

  That is, according to the configuration shown in FIG. 17A, the sensor unit 10 alone (that is, the measuring device is realized by the sensor unit alone) can perform the measurement from the gap to the display of the measurement result.

(Modification 2)
As shown in FIG. 17B, the power supply unit 23 and the wireless communication unit 26 may be provided in the sensor unit 10, and the wireless communication unit 37 may be provided in the processing unit 30. The power supply unit 23 supplies power to each component of the sensor unit 10. The wireless communication units 26 and 37 wirelessly communicate various information performed between the sensor unit 10 and the processing unit 30.

  According to the configuration shown in FIG. 17B, the cord 13 is not necessary, and measurement can be performed without being affected by the cord 13 when measuring the gap, so that convenience is improved.

(Modification 3)
As shown in FIG. 18A, a mirror (for example, a surface mirror) 27 may be provided in the sensor unit 10. That is, the housing unit 12 may have a configuration in which the optical path from the measurement target to the camera 22 is folded back by the mirror 27. When the surface mirror 27 is used as a mirror, double reflection can be prevented.

  In this case, since the size of the casing 12 of the sensor unit 10 along the direction E in the drawing can be shortened, the size of the sensor unit 10 can be reduced.

  Further, as shown in FIG. 18B, a shielding member 28 may be provided so that light from the light source 21 does not enter the camera 22. In this case, shooting can be performed with less influence from the light from the light source 21. In addition, a plurality of light sources 21 may be provided.

(Modification 4)
In addition to the above description, the shape of the support portion 11 will be further described. As shown in FIGS. 19A to 19E, the support portion 11 can be realized in various shapes. FIGS. 19A to 19E show a view of the sensor unit 10 as viewed from the direction of arrow A in FIG. 1 and a view as viewed from the direction of arrow B in FIG.

  In the configuration illustrated in FIG. 19A, the support portion 11 is illustrated as being realized in a shape like a piano wire, for example. In this case, even if the inspection mold 120 has a wavy shape, the gap can be measured.

  In the configuration shown in FIG. 19B and FIG. 19C, a grounding member 11 c having a horizontal shape is added to the grounding portion 11 a of the support portion 11. More specifically, in the configuration of FIG. 19B, the grounding member 11c is formed so as to increase the grounding area by a predetermined length from the support portion 11 along the arrow B direction and the arrow A direction. ing. In the configuration of FIG. 19C, the support portion 11 and the grounding member 11 c have a ground contact area that increases by a predetermined length along the arrow B direction, rather than the length of the support portion 11 along the arrow A direction. Widely formed. Further, the grounding member 11c is formed so as to increase the grounding area along the arrow A direction by a predetermined length from the support portion 11.

  In the configurations shown in FIG. 19B and FIG. 19C, since the shake in the arrow B direction and the arrow A direction can be suppressed, the support portion 11 can be easily fixed vertically to the inspection mold 120.

  In the configuration shown in FIGS. 19D and 19E, a grounding member 11c having a horizontal shape is added to the grounding portion 11a of the support portion 11. More specifically, in the configuration of FIG. 19D, the grounding member 11c is formed so as to increase the grounding area by a predetermined length along the arrow B direction as compared to the support portion 11. In the configuration of FIG. 19 (e), the support portion 11 and the ground member 11c have a ground contact area by a predetermined length along the arrow B direction, rather than the length of the support portion 11 and the ground member 11c along the arrow A direction. Widely formed to increase

  In the configuration shown in FIG. 19D and FIG. 19E, it is possible to suppress shaking in the direction of the arrow B, and thus it is easy to fix the support portion 11 to the inspection mold 120 vertically.

(Modification 5)
While the button is pressed (or a predetermined time after the button is pressed), the gap may be repeatedly measured, and the minimum value among the measurement results may be adopted as the actual gap distance. In this case, as shown in FIG. 20, while the button 14 is being pressed, the user tilts the sensor unit 10 in the direction of arrow F, for example, and changes the angle of the support portion 11 with respect to the inspection mold 120.

  When configured in this manner, the measurement value (gap distance) at the time when the support portion 11 is in a state perpendicular to the inspection mold 120 can be obtained more reliably than the above configuration.

(Modification 6)
In the above description, the case where the gap distance is measured when the button 14 is pressed is described, but the present invention is not limited to this. Since the button 14 is pressed by the user pressing the button 14, the sensor unit 10 may be shaken when the button 14 is pressed, and the support portion 11 may not be in a vertical state with respect to the inspection mold 120. .

  Therefore, the distance of the gap may be measured based on the photographed image immediately before the button 14 is pressed. In this case, the processing unit 30 stores the video signals acquired from the sensor unit 10 in order, and when the pressing of the button 14 is detected, the distance of the gap is measured based on the photographed image immediately before the pressing. Just do it.

(Modification 7)
In the above description, the case where the distance of the gap is measured as the button 14 is pressed is described, but the present invention is not limited to this. This button 14 may be omitted.

  As described above, when the sensor unit 10 (support portion 11) is properly grounded, the shadow region s of the gap and the surface of the inspection mold 120 illuminated by the light source 21 are both reflected on the captured image of the camera 22. (See FIGS. 2 and 3).

  On the other hand, while the sensor unit 10 is in the air (that is, not grounded), the contrast (between the lower end of the cut end of the press sheet metal 110 and the shadow area s) as obtained when properly grounded is obtained. Absent. In particular, when the focus of the camera 22 is adjusted so as to be matched with the front end portion of the support portion 11, the distant view will be out of focus, so an extreme contrast difference does not appear in the image.

  The inspection mold 120 is often painted in a specific color (green, light blue, yellow, etc.). For example, when the field of view of the camera 22 is lying down as shown in FIG. Only occasionally, it can be expected that a wider area on the left side of the figure than the first line 61 is occupied by the specific color.

  Using these things, the sensor unit 10 (supporting part 11) is determined to be grounded to the cut of the inspection mold 120 and the press sheet metal 110, and after determining the grounding, the measured value of the distance of the gap is previously determined. When the value becomes constant over a predetermined time (predetermined time), the value may be acquired as the gap distance.

  With this configuration, the button 14 can be omitted from the configuration of the sensor unit 10. In this case, if the user touches the sensor unit 10 at a gap portion to be measured and holds the sensor unit 10 for a certain period of time, the measurement can be automatically performed. Note that an alarm sound may be sounded when the measurement is completed, or a lamp may be turned on (including blinking).

(Modification 8)
In the above description, the case where the boundary between the sheet metal lower end region 44 and the shadow region 43 is detected has been described, but the present invention is not limited to this. For example, when the thickness of each part at the edge of the press sheet metal 110 can be accurately grasped and the cut end of the press sheet metal 110 is kept dark and cannot be distinguished from the shadow area, the sheet metal upper end area 45 and the shadow area 43 The actual gap distance may be calculated on the basis of the boundary, and the final gap distance may be obtained by subtracting the thickness of the press sheet metal 110 from the calculated distance.

(Modification 9)
In the above description, the measurement target object is a press sheet metal, the reference object is a check tool (inspection mold), and the gap between the press sheet metal and the inspection mold is measured as an example. Not limited to. The object to be measured may be an object having at least a plate-like measurement surface, and the reference object is an object having at least a reference surface that is flat enough to fix the support portion 11 vertically. If it is good.

DESCRIPTION OF SYMBOLS 10 Sensor unit 20 Processing unit 11 Support part 12 Case part 14 Button 70 Case 74 (74a, 74b) Adjustment pattern 100 Adapter 110 Press sheet metal 120 Inspection type | mold (check tool)
130 Conversion table

Claims (14)

The distance of the gap along the vertical direction from the reference plane to the measurement plane between the measurement target object having the measurement plane and the reference object having the reference plane in which a gap is formed between the measurement plane A measuring device for measuring,
A measuring unit having an imaging unit that captures an area including the measurement surface, the gap, and the reference surface;
Detecting means for detecting a boundary between the measurement surface and the gap from the photographed image based on a change in luminance value on the photographed image photographed by the imaging unit;
A calculating means for calculating a distance of the gap by converting a distance from the reference plane on the photographed image to the boundary into an actual distance;
Display processing means for displaying on a display unit the distance of the gap calculated by the calculating means. The calculating means includes
The distance of the gap is calculated using a conversion table that defines information for converting a distance from the reference plane on the captured image to the boundary into an actual distance. Measuring device. The conversion table is
Defining information for converting a distance from a predetermined reference position on the reference plane of the captured image to each position on the captured image into an actual distance;
The calculating means includes
The distance of the gap corresponding to the distance from the reference position of the captured image to the boundary is calculated by referring to the conversion table based on the position where the boundary is detected in the captured image. The measuring apparatus according to claim 2. The measuring means includes
A housing having a light source that irradiates light to an area including an edge of the measurement target object, and the imaging unit that is disposed at a position where a shadow area generated in the gap due to light irradiation from the light source can be photographed And
A rod-shaped support portion that extends from the housing portion along a predetermined direction and is longer than a length of the gap along the vertical direction;
The support part is
A grounding portion that is grounded on the reference surface of the reference object when measuring the distance of the gap, and the side surface of the measurement object is grounded when the grounding portion is grounded with respect to the reference surface The measurement apparatus according to claim 1, wherein the measurement apparatus is grounded to an edge of the measurement surface. At least in a state where the support portion is stored in a case capable of storing the support portion, the grounding portion of the support portion is grounded to the first surface inside the case, and the first surface is The side surface of the support portion is grounded with respect to the second surface inside the case formed in a vertical direction.
In the second surface,
An adjustment pattern in which a plurality of adjustment lines are arranged at equal intervals starting from the boundary with the first surface is formed,
The measuring device is
Adjustment pattern detecting means for detecting the adjustment pattern from the photographed image based on a change in luminance value on the photographed image photographed by the imaging unit in a state where the support part is stored in the case;
Based on the interval between the adjustment lines detected on the photographed image and the actual interval between the adjustment lines held in advance, the distance from the reference plane to the boundary on the photographed image is converted into an actual distance. And a calibration processing means for updating a conversion table defining information for updating and updating a reference position on the reference plane based on the adjustment line detected on the photographed image. The measuring device according to claim 4. In the support part,
Scales are formed at equal intervals along the predetermined direction,
The calculating means includes
The gap distance corresponding to the distance from the reference plane to the boundary on the photographed image is calculated based on the scale information along the gap detected on the photographed image. The measuring device according to claim 4. The measuring device is
An adapter that is configured to be movable along the outer shape of the housing portion and that is detachably attached to the housing portion;
The adapter includes
The measurement apparatus according to claim 4, wherein an adapter grounding unit that grounds at least one of the measurement target object and the reference object is provided when measuring the distance of the gap. The measurement target object is made of a metal material,
The measuring device according to claim 7, wherein the adapter grounding unit and the support unit include a magnet. The measuring device is
A button for instructing start of measurement of the gap distance;
The detection means includes
The boundary detection is performed on a photographed image photographed by the imaging unit when the user presses the button before the button is pressed. The measuring device according to item 1. The measuring device is
A button for instructing the start of measurement;
The detecting means and the calculating means are:
While the button is pressed or for a predetermined time after the button is pressed, the boundary detection and the calculation of the gap distance based on the detected boundary are repeatedly performed, and a plurality of calculation results The measuring device according to any one of claims 1 to 8, wherein the smallest value is adopted as the distance of the gap. The detecting means and the calculating means are:
The detection of the boundary and the calculation of the distance of the gap based on the detected boundary are repeatedly performed, and the value when the value obtained by the calculation becomes constant for a predetermined time is determined as the distance of the gap. It employ | adopts as. The measuring device of any one of Claim 1 to 8 characterized by the above-mentioned. On the reference surface of the reference object,
A design line is formed along an edge of the measurement surface of the measurement target object, and a trim line is formed with a predetermined distance relationship along the design line,
The conversion table is
Further defining information for converting a distance from a predetermined reference position on the reference plane of the captured image to a predetermined position on the reference plane of the captured image into an actual distance;
The measuring device is
The measurement apparatus according to claim 2, further comprising: a horizontal distance calculation unit that calculates a distance from the reference position on the photographed image to the trim line using the conversion table. The housing part further comprises a mirror,
The measurement apparatus according to claim 4, wherein the imaging unit photographs a shadow region generated in the gap by irradiation of light from the light source through the mirror. The distance of the gap along the vertical direction from the reference plane to the measurement plane between the measurement target object having the measurement plane and the reference object having the reference plane in which a gap is formed between the measurement plane A processing method of a measuring device for measuring,
An image capturing unit of a measuring unit that captures an area including the measurement surface, the gap, and the reference surface;
A step of detecting a boundary between the measurement surface and the gap from the captured image based on a change in luminance value on the captured image captured by the imaging unit;
A step of calculating a distance of the gap by converting a distance from the reference plane on the captured image to the boundary into an actual distance;
A display processing unit including a step of displaying a distance of the gap calculated by the calculation unit on a display.

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