Bent-shape measurement method, bent-shape measurement program, and bent-shape measurement device

Abstract

This bent-shape measurement method is for measuring the shape of a molding material to which bending has been applied, and includes: a data acquisition step for acquiring profile data generated by imaging a part of a side surface of the molding material; a detection step for detecting, by using the profile data, straight sections, in which the molding material extends linearly, for a plurality of areas set for the molding material; a calculation step for calculating the intersection point of two straight sections in each area; and a conversion step for converting the intersection point into a setting value on the basis of the coordinates of the intersection point in each area.

Description

Bending shape measuring method, bending shape measuring program, and bending shape measuring device

[0001] The present invention relates to a bending shape measuring method, a bending shape measuring program, and a bending shape measuring device.

[0002] A stabilizer used in a vehicle or the like is attached to the vehicle to stabilize the vehicle's posture. The stabilizer is manufactured by bending a rod-shaped member. In this case, the bending conditions are set based on, for example, placing the bent member on a full-form gauge and visually determining the clearance within the gauge. In order to improve the accuracy of such shape measurements, a technology has been disclosed in which an image of a three-dimensional structure is captured and the captured data is compared with design data to determine whether the shape after bending is within a tolerance range (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 9-184712

[0004] However, the technique disclosed in Patent Document 1 has the problem that it takes time to capture an image of a three-dimensional structure.

[0005] The present invention has been made in consideration of the above, and aims to provide a bending shape measuring method, a bending shape measuring program, and a bending shape measuring device that can obtain the shape after bending in a short period of time.

[0006] In order to solve the above-mentioned problems and achieve the object, the bending shape measurement method of the present invention is a bending shape measurement method for measuring the shape of a molded material that has been bent, and includes a data acquisition step for acquiring profile data generated by imaging a portion of the side of the molded material, a detection step for detecting straight portions of the molded material extending in a straight line using the profile data for multiple areas set for the molded material, a calculation step for calculating the intersection of two straight portions in each area, and a conversion step for converting the coordinates of the intersection in each area into set values.

[0007] In addition, the bending shape measuring method of the present invention is characterized in that, in the above invention, the conversion step converts the value of the bending shape of the formed material represented by the coordinates of the bending intersection into the set value based on the coordinates of the bending intersection.

[0008] In addition, in the bending shape measuring method according to the present invention, a correction value is calculated based on the difference between the converted set value and a preset set value.

[0009] In the bent shape measuring method according to the present invention, in the above invention, the detecting step changes the detection position of the straight portion and repeats the detection to update the detection result of the straight portion.

[0010] Moreover, the bending shape measuring method according to the present invention is characterized in that, in the above invention, it further comprises a combining step of combining the profile data of each area.

[0011] In addition, the bending shape measurement program of the present invention is a bending shape measurement program that causes a computer to measure the shape of a formed material that has been bent, and is characterized in that it causes the computer to execute the following steps: a data acquisition step of acquiring profile data generated by imaging a portion of the side of the formed material; a detection step of detecting straight portions of the formed material extending in a straight line using the profile data for multiple areas set for the formed material; a calculation step of calculating the intersection of two straight portions in each area; and a conversion step of converting the coordinates of the intersection in each area into set values.

[0012] In addition, the bending shape measuring device of the present invention is a bending shape measuring device that measures the shape of a formed material that has been bent, and is characterized by including: a data acquisition unit that acquires profile data generated by imaging a portion of the side of the formed material; a detection unit that uses the profile data to detect straight portions of the formed material where the formed material extends in a straight line for multiple areas set for the formed material; a calculation unit that calculates the intersection of two straight portions in each area; and a conversion unit that converts the coordinates of the intersection in each area into a set value.

[0013] According to the present invention, it is possible to obtain the shape after bending in a short time.

[0014] FIG. 1 is a diagram showing an example of the configuration of a stabilizer. FIG. 2 is a block diagram showing a schematic configuration of a shape measuring device according to an embodiment of the present invention. FIG. 3 is a flowchart showing the flow of shape measurement processing performed by the shape measuring device according to an embodiment of the present invention. FIG. 4 is a diagram for explaining imaging processing of a member after bending. FIG. 5 is a diagram showing an example of profile data. FIG. 6 is a diagram for explaining area setting of imaging data of a member after bending. FIG. 7 is a diagram (part 1) for explaining detection of a straight portion. FIG. 8 is a diagram (part 2) for explaining detection of a straight portion. FIG. 9 is a diagram for explaining calculation of an intersection point of straight lines. FIG. 10 is a diagram for explaining resetting of detection positions. FIG. 11 is a flowchart showing the flow of shape measurement processing performed by a shape measuring device according to a modified embodiment of the present invention.

[0015] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. Note that the drawings are schematic, and the relationship between the thickness and width of each part, the thickness ratio of each part, etc. may differ from the actual ones, and the drawings may also include parts with different dimensional relationships and ratios.

[0016] (Embodiment) Fig. 1 is a diagram showing an example of the configuration of a stabilizer. The stabilizer 100 is a solid or hollow cylindrical member made of metal or various fibers (e.g., carbon fiber). Fig. 1 shows an example of a stabilizer made using a hollow member. The stabilizer 100 is made by bending both ends of a cylindrical member. In the following description, the bent member (formed material) may be referred to as the formed material 100.

[0017] Fig. 2 is a block diagram showing a schematic configuration of a shape measuring device according to one embodiment of the present invention. The shape measuring device 1 shown in Fig. 1 is a device for measuring the shape of a formed material. The shape measuring device 1 has a data acquisition unit 11, a detection unit 12, a calculation unit 13, an area setting unit 14, an input unit 16, an output unit 17, a memory unit 18, and a control unit 19.

[0018] The data acquisition unit 11 acquires shape data of the formed material. In this embodiment, the shape data is profile data obtained by photographing the formed material.

[0019] The detector 12 detects the straight portion of the formed material. The detector 12 detects a position in a setting area of ​​the profile data that corresponds to the straight portion extending linearly in the preset design data of the formed material. The profile data of the formed material includes a plurality of mutually different areas that include the entire formed material.

[0020] The calculation unit 13 calculates, for the plurality of straight sections detected by the detection unit 12, intersections between adjacent (connected) straight sections in the design with a bend therebetween.

[0021] The area setting unit 14 sets an area for calculating the bending intersection coordinates for the profile data, and resets the detection area for the detection unit 12 using the intersections calculated by the calculation unit 13.

[0022] The synthesizing unit 15 synthesizes the profile data of the formed material in each area, and by this synthesis, the coordinates of the bending intersections of the entire formed material are set.

[0023] The input unit 16 receives input of various signals related to the operation of the form measuring device 1. The input unit 16 is configured using a keyboard, a mouse, a switch, a touch panel, and the like.

[0024] The output unit 17 displays images and outputs sounds and lights under the control of the control unit 19. The output unit 17 is configured using a display, a speaker, a light source, and the like.

[0025] The storage unit 18 stores programs (e.g., a shape measurement program described later) for the control unit 19 to execute various operations. The storage unit 18 is configured using a volatile memory or a nonvolatile memory, or a combination of these. For example, the storage unit 18 is configured using a RAM (Random Access Memory), a ROM (Read Only Memory), etc.

[0026] The control unit 19 controls the operation processing of each component of the shape measuring device 1. For example, when an instruction to start a shape measurement process is input via the input unit 16, the control unit 19 causes each unit to execute the process.

[0027] The detection unit 12, calculation unit 13, area setting unit 14, synthesis unit 15 and control unit 19 are each configured using a processor such as a CPU (Central Processing Unit) or various arithmetic circuits that perform specific functions, such as an ASIC (Application Specific Integrated Circuit).

[0028] Next, the shape measurement process will be described with reference to Figs. 3 to 9. Fig. 3 is a flowchart showing the flow of the shape measurement process performed by the shape measuring device according to one embodiment of the present invention. For example, when an instruction to start the shape measurement process is input via the input unit 16, the control unit 19 causes each unit to execute the process. In the following description, it is assumed that in the profile data of the formed material, a plurality of areas are set in advance in correspondence with the design data, and each area is assigned a number (1, 2, ..., N MAX ) will be used as the reference numerals.

[0029] First, the control unit 19 acquires profile data (step S101). The control unit 19 causes the data acquisition unit 11 to acquire the profile data of the formed material for which the coordinates of the bending intersections are to be calculated.

[0030] 4 is a diagram for explaining the imaging process of a workpiece after bending. The profile data is acquired by imaging the formed workpiece 100 while moving an imaging member 200 relative to the formed workpiece 100, thereby acquiring multiple images constituting the entire formed workpiece 100. Here, the imaging member 200 is configured using, for example, a position sensitive detector (PSD), a charge coupled device (CCD) image sensor, a complementary metal oxide semiconductor (CMOS) image sensor, or the like.

[0031] In this embodiment, an example will be described in which the imaging member 200 is movable in two mutually perpendicular directions and moves on a plane perpendicular to the optical axis of the imaging member 200. Therefore, the profile data is obtained by imaging the molded material 100 from one direction. Note that the imaging member 200 may be movable in three-dimensional space to image the entire circumference of the molded material 100.

[0032] Fig. 5 is a diagram showing an example of profile data. Fig. 5 shows a portion of the profile data. As shown in Fig. 5, the profile data is point cloud data showing the side surface of the molded piece 100 facing the imaging member 200.

[0033] The area setting unit 14 sets the area number N to N=1 (step S102).

[0034] Here, the areas in the profile data will be explained with reference to FIG. 6 . FIG. 6 is a diagram for explaining the area setting of the image data of a workpiece after bending. In the design data, multiple areas R1 to R6 are set for the formed material 100, following the extension direction of the formed material 100. Area R1 is located in the center of the extension direction of the formed material 100 and includes a straight portion in the center of the longitudinal direction of the formed material 100 and one bent portion connected to the straight portion. Area R2 is located in the center of the extension direction of the formed material 100 and includes a straight portion in the center of the longitudinal direction of the formed material 100 and the other bent portion connected to the straight portion. Area R3 is adjacent to area R1 along the extension direction of the formed material 100 and includes one bent portion. Area R4 is adjacent to area R2 along the extension direction of the formed material 100 and includes one bent portion. Area R5 is adjacent to area R3 along the extension direction of the molded material 100 and includes one end of the molded material 100. Area R6 is adjacent to area R4 along the extension direction of the molded material 100 and includes one end of the molded material 100. Note that adjacent areas may be partially overlapped.

[0035] 3 , the detection unit 12 detects a straight portion for the Nth area (step S103). The detection unit 12 reads design data from the storage unit 18 or an external server, and by referring to the read design data, associates the area with a position (coordinate) in the profile data, thereby detecting a straight portion in the area.

[0036] 7 and 8 are diagrams for explaining the detection of straight portions. As shown in FIG. 7 , when position P1 is set as the straight portion of the formed material 100 in the detection area of ​​the bend intersection coordinates, the detection unit 12 detects the straight portion at position P1. Note that position P1 is set based on design data and is a position estimated to be the straight portion based on the profile data of the formed material 100. Position P1 may be set as the coordinates of a representative point, or may be set as the coordinates of the center of gravity of the formed material 100 included in position P1 based on the profile data of the formed material 100, or may be set as a space through which the straight portion can pass. At least two such set positions are set for each area, sandwiching a bend.

[0037] The detection unit 12 extracts one circumferential point cloud data 310 from the point cloud data representing the surface of the molded material 100 (see (a) of FIG. 8). Then, the detection unit 12 generates a circle 311 that matches the point cloud data 310 (see (b) of FIG. 8). Note that if the circle 311 does not match completely because there is a blur in part of the point cloud data 310 due to measurement error or the like, the circle that passes through the most points is selected. Note that the circle 311 may use design values ​​for some points. After generating the circle 311, the detection unit 12 sets the coordinates of the center 312 of the circle 311 (see (c) of FIG. 8).

[0038] The detector 12 sets the coordinates of the centers of the multiple circumferential point cloud data sets that are different from each other at the position P1. Then, the detector 12 calculates an approximation line (center approximation line) using the coordinates of the multiple centers that have been set. This allows the straight portion of the formed material 100 to be detected.

[0039] 3 , after detecting the straight portion, the calculation unit 13 calculates (step S104) the intersections of the straight lines (center approximation lines) corresponding to the straight portions of the formed material 100. The calculation unit 13 calculates the coordinates of the intersections of the center approximation lines generated in the area.

[0040] 9 is a diagram for explaining calculation of the intersection of straight lines. As shown in FIG. 9, when the center approximation lines 401 and 402 do not intersect with each other, the calculation unit 13 calculates the line segment L1 that connects the center approximation lines 401 and 402 at the shortest distance, and sets the midpoint 430 of the line segment L1 as the coordinates of the intersection.

[0041] Returning to Fig. 3, after calculating the intersection, the detection unit 12 resets the detection position (step S105). The detection unit 12 determines the straight portion detection position as a position moved a predetermined value from the intersection calculated by the calculation unit 13. At this time, the detection unit 12 moves the detection position along the center approximation line by a predetermined value in a direction away from the bent portion. By moving the detection position in this way, multiple intersections are calculated for one bent position.

[0042] The control unit 19 then determines whether the number of repetitions of the intersection calculation in the Nth area is equal to or less than the upper limit (step S106). If the control unit 19 determines that the number of repetitions is greater than the upper limit (step S106: No), the control unit 19 proceeds to step S107. On the other hand, if the control unit 19 determines that the number of repetitions is equal to or less than the upper limit (step S106: Yes), the control unit 19 proceeds to step S103, where the straight portion detection process is repeated at the reset position to update the detection result. This repeated straight portion detection improves the detection accuracy of the straight portion. In this case, the upper limit is set based on the detection accuracy based on past performance, etc. In this embodiment, the intersection (bend intersection) in the Nth area is the intersection calculated last through the repetition. However, it may also be an intersection calculated when the intersection is set in any order of the repetition, or the center of gravity of a shape passing through multiple calculated intersections. Note that the repetitive process of step S106 can be omitted. Furthermore, for areas R5 and R6 that do not include a bent portion, the processing of steps S103 to S106 is omitted.

[0043] Here, the resetting of the detection position will be described with reference to Fig. 10. Fig. 10 is a diagram for explaining the resetting of the detection position. First, as the detection positions, first detection position P D1 and the second detection position P D2For example, in step S104, the calculation unit 13 calculates the first detection position P D1 and the second detection position P D2 Then, the calculation unit 13 calculates the center approximation lines 403 and 404 of the first detection position P D1 At this time, the calculation unit 13 resets the first detection position to the second detection position P D2 The first detection position P is a position that is a predetermined value D away from the center approximation line 404 of D3 The predetermined value D1 is preferably set to be equal to or greater than the bending radius of the bent portion, since it is moved from the bent portion toward the straight portion. After detecting the intersection by resetting the first detection position, the second detection position is moved by a predetermined value using the center approximation line of the first detection position as a reference. The predetermined value may also be increased depending on the number of repetitions.

[0044] 3, in step S107, the control unit 19 increments N by 1. After that, the control unit 19 MAX (Step S108). MAX If it is determined that N is equal to or less than N (step S108: No), the process proceeds to step S103, and the above-described process is repeated for the increased Nth number. MAX If it is determined that the value is greater than the threshold (step S108: Yes), the process proceeds to step S109.

[0045] In step S109, the combining unit 15 combines the profile data of the formed material in each area. This combination sets the coordinates of the bending intersections of the entire formed material. The combining unit 15 combines the data of each area by matching reference blocks in the areas, matching areas based on encoder values, matching reference patterns provided on the measurement table, and matching feature points of the imaged object. Note that the combination by the combining unit 15 can be performed using a known method.

[0046] Thereafter, the calculation unit 13 converts the coordinates of the bend intersections into set values ​​(step S110). At this time, the calculation unit 13 converts the coordinates of the bend intersections into set values, for example, by inputting the coordinates of the bend intersections into a calculation formula created in advance. The set values ​​are, for example, values ​​corresponding to the design data.

[0047] The calculation unit 13 then calculates correction values ​​using the converted setting values ​​and the setting values ​​in the design data (step S111). The correction values ​​are, for example, values ​​set as processing conditions during bending, and are values ​​that change the feed rate / speed, bending angle, and twist angle.

[0048] After calculating the correction value, the control unit 19 may, for example, cause the calculated correction value to be displayed on the output unit 17 or may store it in the storage unit 18. Furthermore, the control unit 19 may transmit the correction value to a control unit of a device that performs bending, and cause the device to automatically correct the setting value.

[0049] In steps S110 and S111, the calculation unit 13 converts, for example, multiple reference coordinates indicating drawing values ​​on the design drawing at the bending position of the formed material and the calculated coordinates (measurement coordinates) of multiple bending intersections into set values ​​based on the values ​​of each coordinate. At this time, one measurement coordinate corresponds to one reference coordinate, and the calculation unit 13 calculates set values ​​for each coordinate, for example, for feed, twist, and bending. The calculation unit 13 then calculates the difference between the set value of the reference coordinate and the set value of the corresponding measurement coordinate. This calculates the difference for each of feed, twist, and bending for the bending process. For example, this difference is set as a correction value. The set values ​​for feed, twist, and bending are expressed based on the relative positional relationship between adjacent points in the arrangement direction. At this time, coordinates may be converted to the same space as needed.

[0050] In the present embodiment described above, the center approximation lines of the two straight sections connected via the bent section in the formed material 100 are calculated, and a set value is calculated from the coordinates of the intersection of each center approximation line, and a correction value is calculated as the difference from the design data. According to this embodiment, the correction value can be calculated using data on a portion of the formed material 100 and the design data, without calculating the bending angle of the bent section from three-dimensional data, for example, so that the shape after bending can be obtained in a short time.

[0051] (Modification) Next, a modification of the embodiment of the present invention will be described with reference to Fig. 11. The configuration of the shape measuring device according to this modification is the same as that of the embodiment, and therefore a description thereof will be omitted. Below, processing that differs from the embodiment will be described. Fig. 11 is a flowchart showing the flow of shape measurement processing performed by the shape measuring device according to this modification.

[0052] The control unit 19 causes each unit to execute processing when, for example, an instruction to start shape measurement processing is input via the input unit 16. The control unit 19 acquires profile data in the same manner as in step S101 (step S201).

[0053] Then, the synthesizing unit 15 synthesizes the profile data of the molding material in each area (step S202). This synthesis generates imaging data corresponding to the entire molding material. Note that if the entire image of the molding material 100 can be obtained in a single image capture, step S202 can be omitted.

[0054] Thereafter, the control unit 19 detects straight portions for each area in the same manner as in steps S102 to S108, and calculates the coordinates of the intersections between the center approximation lines (steps S203 to S209).

[0055] Thereafter, the calculation unit 13 converts the coordinates of the bend intersections into set values ​​(step S210). At this time, the calculation unit 13 converts the coordinates of the bend intersections into set values, for example, by inputting the coordinates of the bend intersections into a calculation formula created in advance. The set values ​​are, for example, values ​​corresponding to the design data.

[0056] The calculation unit 13 then calculates correction values ​​using the converted setting values ​​and the setting values ​​in the design data (step S211). The correction values ​​are, for example, values ​​set as processing conditions during bending, and are values ​​that change the feed rate / speed, bending angle, and twist angle.

[0057] After calculating the correction value, the control unit 19 may, for example, cause the calculated correction value to be displayed on the output unit 17 or may store it in the storage unit 18. Furthermore, the control unit 19 may transmit the correction value to a control unit of a device that performs bending, and cause the device to automatically correct the setting value.

[0058] In the present modification described above, similar to the embodiment described above, the center approximation lines of the two straight sections connected via the bent section in the formed material 100 are calculated, and a set value is calculated from the coordinates of the intersection of each center approximation line, and a correction value is calculated as the difference from the design data. According to this modification, the correction value can be calculated using data on a portion of the formed material 100 and the design data without calculating, for example, the bending angle of the bent section from three-dimensional data, so the shape after bending can be obtained in a short time.

[0059] Although the embodiments for carrying out the present invention have been described above, the present invention should not be limited to only the above-described embodiments.

[0060] In addition, the program to be executed by the shape measuring device of this embodiment is provided, for example, as file data in an installable format or an executable format, recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk), a USB medium, or a flash memory.

[0061] Furthermore, the program executed by the shape measuring device according to this embodiment may be configured to be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network.

[0062] The shape measuring device according to this embodiment can also be configured to function as a server device and transmit and receive information to and from an external terminal connected via a network.

[0063] As such, the present invention may include various embodiments not described here, and various design changes may be made within the scope of the technical idea specified by the claims.

[0064] As described above, the bent shape measuring method, bent shape measuring program, and bent shape measuring device according to the present invention are suitable for obtaining the shape after bending in a short period of time.

[0065] REFERENCE SIGNS LIST 1 Shape measuring device 11 Data acquisition unit 12 Detection unit 13 Calculation unit 14 Area setting unit 15 Synthesis unit 16 Input unit 17 Output unit 18 Storage unit 19 Control unit 100 Stabilizer 200 Imaging member

Claims

1. A bending shape measuring method for measuring the shape of a molded material that has been bent, comprising: a data acquisition step for acquiring profile data generated by imaging a portion of the side of the molded material; a detection step for detecting straight portions of the molded material extending in a straight line using the profile data for a plurality of areas set for the molded material; a calculation step for calculating an intersection point of two straight portions in each area; and a conversion step for converting the coordinates of the intersection point in each area into a set value.

2. The bending shape measuring method according to claim 1, characterized in that the conversion step converts the value of the bending shape of the formed material represented by the coordinates of the bending intersection into the set value based on the coordinates.

3. The bending shape measuring method according to claim 1, further comprising the step of calculating a correction value based on a difference between the converted set value and a preset set value.

4. The bending shape measuring method according to claim 1, characterized in that the detection step changes the detection position of the straight portion and repeats detection to update the detection result of the straight portion.

5. The bending shape measuring method according to claim 1, further comprising a synthesis step of synthesizing the profile data of each area.

6. A bending shape measuring program that causes a computer to measure the shape of a formed material that has been bent, comprising: a data acquisition step of acquiring profile data generated by imaging a portion of the side of the formed material; a detection step of detecting straight portions of the formed material extending in a straight line using the profile data for a plurality of areas set for the formed material; a calculation step of calculating an intersection point of two straight portions in each area; and a conversion step of converting the coordinates of the intersection point in each area into a set value.

7. A bending shape measuring device for measuring the shape of a formed material that has been bent, comprising: a data acquisition unit for acquiring profile data generated by imaging a portion of the side of the formed material; a detection unit for detecting straight portions of the formed material extending in a straight line using the profile data for a plurality of areas set for the formed material; a calculation unit for calculating an intersection point of two straight portions in each area; and a conversion unit for converting the coordinates of the intersection point in each area into a set value.

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