Shape measurement method for material to be measured, shape measurement device for the same, and method for manufacturing product

Abstract

To provide a technique capable of automatically, accurately, and efficiently measuring a shape of a material to be measured.SOLUTION: A shape measurement method for measuring a shape of a material 1 to be measured includes: an area specifying step of acquiring two or more feature point existing areas SA, each of which is an area in which a feature point for specifying the shape of the material 1 to be measured is estimated to exist; a precise measurement step of acquiring a surface shape of specified each feature point existing area SA as precise measurement data composed of a set of three-dimensional point groups; and a feature point position calculation step of obtaining information on a position P of the feature point existing in each feature point existing area SA from the acquired precise measurement data.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for measuring the shape of a workpiece such as a metal plate with high accuracy, and a technique for manufacturing a product using the technique. The present invention is particularly effective for a workpiece whose reference shape as viewed from the measurement direction is known in advance. [Background technology]

[0002] For example, in the thick plate refining process of a steelworks, there is a cutting process in which the rolled material produced in the rolling process is cut to a specified dimension. For example, gas cutting, laser cutting, plasma cutting, or other cutting methods are used. The work of the cutting process itself is being automated by using a numerically controlled cutting device with a gate-type movable part or a self-propelled cutting device as a cutting device.

[0003] However, dimensional measurements and flatness measurements of thick plates (measured materials) before and after cutting are still largely done manually. Such manual measurement work, such as measuring the shape of thick plates after cutting, is heavy physical labor. Furthermore, measuring the dimensions of thick plates is a task that carries the risk of accidents such as falls due to poor work footing, and collisions and cramps due to interference between the worker and the cutting device, as the work requires entering the production line. Furthermore, because measurements are done manually, there are concerns about the accuracy of the measurement, including personal differences and human error, and there are issues with accuracy due to the inability to take many measurement points.

[0004] In response to this, a non-contact measurement method using optical means has been disclosed as a method for measuring the dimensions of thick plates without relying on human labor. For example, Patent Document 1 discloses a measurement method using a sensor system that employs a light-cutting method in which a laser beam is irradiated onto the material to be measured, and the irradiated laser is captured by a camera from a different angle to measure the shape of the material to be measured. Patent Document 2 also discloses that a non-contact distance sensor is mounted on a gate-type cutting device, and the outside dimensions of the material to be cut (material to be measured) are calculated from the sensing data of the distance sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6780533 [Patent Document 2] JP 2000-158169 A Summary of the Invention [Problem to be solved by the invention]

[0006] The method of Patent Document 1 uses a light-cutting method to measure the shape of the material to be measured. Therefore, it is possible to measure the shape of the material to be measured with high accuracy. However, the width dimension of the thick plate cut in the thick plate refining process is generally large, about 1000 mm to 5000 mm, and the placement position of the thick plate to be measured is not constant. On the other hand, if a sensor system using the light-cutting method is used to accurately measure the dimensions of the thick plate with a resolution of 1 mm or less, only a range of about 400 mm width can be measured at one time. In this way, when the placement position of the thick plate is not constant and a thick plate with a large width dimension as described above is to be measured using a sensor system using the light-cutting method, it is necessary to arrange multiple sensors. Therefore, the method of Patent Document 1 is expensive and inefficient.

[0007] In addition, in the cutting device of Patent Document 2, when measuring the shape data of the workpiece, sensing is performed by scanning the distance sensor in a zigzag pattern over the entire area of ​​the workpiece. Therefore, the method of Patent Document 2 increases the cycle time and the measurement data size becomes huge, resulting in poor efficiency.

[0008] The present invention has been made in light of the above-mentioned points, and one of its objects is to provide a technique that can automatically measure the shape of a workpiece with high accuracy and efficiency. [Means for solving the problem]

[0009] The inventors have come up with a simple method for obtaining rough information on the positions of each characteristic point that specifies the shape of the measured material, and then measuring the area (narrow area) of the rough information with high accuracy to obtain the positions of each characteristic point that can specify the shape of the measured material with high accuracy. They have found that this method makes it possible to easily and accurately measure the shape of the measured material even if the dimensions of the measured material are large. Based on this finding, the present invention has been made.

[0010] In order to solve this problem, one aspect of the present invention is a shape measurement method for measuring the shape of a workpiece, comprising: an area identification step for acquiring two or more feature point existence areas which are areas in which feature points that specify the shape of the workpiece to be measured are estimated to exist; a precision measurement step for acquiring the surface shape of each of the identified feature point existence areas as precision measurement data consisting of a collection of three-dimensional point clouds; and a feature point position calculation step for determining positional information of the above-mentioned feature points existing in each feature point existence area from the acquired precision measurement data.

[0011] Another aspect of the present invention is a shape measuring device for measuring the shape of a workpiece, comprising an area identification unit for acquiring two or more feature point existence areas which are areas in which feature points specifying the shape of the workpiece to be measured are estimated to exist, a precision measurement unit for acquiring the surface shape of each of the acquired feature point existence areas as precision measurement data consisting of a collection of three-dimensional point clouds, and a feature point position calculation unit for determining, from the acquired precision measurement data, positional information of the feature points existing in the corresponding feature point existence areas. Effect of the Invention

[0012] According to an aspect of the present invention, for example, the shape of the workpiece is roughly measured to extract a feature point region, and then the surface shape of the feature point region is narrowed down to a smaller area, thereby obtaining position information of two or more feature points that can identify the shape of the workpiece. As a result, according to the aspects of the present invention, the shape of the workpiece can be automatically measured with high accuracy and efficiency. Shape measurement includes, for example, dimensional measurement and profile measurement of the workpiece. [Brief description of the drawings]

[0013] [Figure 1] 10A and 10B are diagrams illustrating examples of feature point positions and feature point existence regions. [Diagram 2] FIG. 2 is a diagram showing an example of a processing configuration of a shape measuring method according to an embodiment based on the present invention. [Diagram 3] 1 is an enlarged view showing an example of a relationship between a feature point position P' determined by rough measurement, a feature point existence area SA based on the feature point position P', and an actual feature point position P. FIG. [Figure 4] 1A and 1B are schematic diagrams illustrating a configuration of a shape measuring device according to an embodiment of the present invention, in which (a) is a side view and (b) is a plan view. [Diagram 5] 1A to 1C are diagrams showing examples of the support state of a workpiece placed in a cutting area. [Figure 6] FIG. 2 is a diagram illustrating a configuration of a shape calculation unit. [Figure 7] 1 is a schematic diagram for explaining rough measurement, in which (a) is a side view and (b) is a plan view. [Figure 8] FIG. 13 illustrates an example of a processing flow of an extraction unit. [Figure 9] FIG. 13 is a diagram illustrating the process of an extraction unit. [Figure 10] 11A and 11B are diagrams illustrating the processing of a precision measurement unit. [Figure 11] 11A and 11B are diagrams illustrating the processing of a feature point position calculation unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, an embodiment of the present invention will be described with reference to the drawings.

[0015] (composition) <Measurement material> The material to be measured is, for example, a thick plate made of metal such as steel, aluminum, titanium, etc. However, the material of the material to be measured may be resin, etc. In addition, since the measurement is non-contact, the material to be measured is not particularly limited as long as it can maintain a certain shape.

[0016] In the following embodiment, the shape of the measured material is a thick plate having a rectangular (quadrangular) shape in a plan view. In this specification, the plan view refers to the appearance when viewed from the measurement direction. In this example, the plan view is described as a top view.

[0017] In the present invention, the shape of the workpiece in plan view is not limited to a rectangular shape, and may be other polygonal shapes, circular shapes, elliptical shapes, etc. If the reference shape (contour shape) of the workpiece in plan view is known in advance, there is no problem because characteristic points that specify the shape can be set. Also, in the present invention, the overall shape of the workpiece does not have to be flat.

[0018] In other words, if the basic shape of the outer periphery of the workpiece in plan view is known in advance, it is possible to set multiple characteristic points that specify the shape of the workpiece, and by determining the positions of the multiple characteristic points, it becomes possible to measure the shape of the workpiece. Examples of the shape that can be specified include the dimensions and profile shape of the workpiece. In this embodiment, a case will be illustrated in which the shape of a workpiece made of a thick plate cut by a cutting device is measured, at least either before or after cutting.

[0019] <About the location of feature points> As shown in FIG. 1, if the measurement material 1 has a rectangular shape, at least four corner positions may be set as the feature point positions P. Furthermore, the feature point positions P may be set separately at intermediate positions of the sides. If the measurement material 1 has a circular shape, any three or more points on the contour of the measurement material 1 may be set as the feature point positions P. The feature point positions P may be set at positions where the center position and radius of the circle can be obtained. In this way, the feature point positions P are set according to the reference shape, and are not limited to the above examples as long as the shape of the measurement material 1 to be measured can be specified. The location of the feature point positions P may be set in advance. Note that the feature point positions P are set at two or more positions. If only the width dimension of a rectangular shape is to be measured, the feature point positions P may be set at two positions in the width direction.

[0020] 1, four corner positions are set as characteristic point positions P. If the four corner positions can be identified, the dimensions and profile of the measurement target material 1 can be identified.

[0021] 1, an area in which the position P of each feature point is estimated to exist is set as a feature point existence area SA. The feature point existence area SA does not need to be rectangular and may be circular or the like. In this embodiment, it is assumed that a sensor that measures inside the feature point existence area SA moves in one direction, so the feature point existence area SA is set to a rectangular shape aligned with the movement direction of the sensor.

[0022] The size of the feature point existence region SA can be set to a range that includes the range of the above-mentioned error, centered on the estimated feature point position P, taking into account the error due to the resolution used to extract the feature point position P. The feature point existence area SA is also called a precise measurement area.

[0023] (Shape measurement method) The shape measuring method is a method for measuring the shape of the object 1 to be measured. The shape measuring method of this embodiment includes an area specifying step 30, a precision measuring step 31, a feature point position calculating step 32, and a dimension calculating step 33, as shown in FIG.

[0024] <Area identification process 30> The region specifying step 30 performs a process of specifying each of the feature point existing regions SA, which are regions in which the positions P of the feature points that specify the shape of the measured material 1 to be measured are estimated to exist. The region specifying step 30 of this embodiment includes a rough measurement step 30A and an extraction step 30B.

[0025] [Rough measurement process 30A] The rough measurement step 30A performs a process of acquiring the surface shape of the entire measured material 1 as rough measurement data consisting of a set of three-dimensional points. The surface shape is the shape seen from the measurement direction. The set of three-dimensional points may be measured using a known sensor capable of measuring a three-dimensional point cloud, such as a laser scanner or a camera (image analysis).

[0026] [Extraction process 30B] The extraction step 30B performs processing to extract each feature point existing area SA from the rough measurement data acquired in the rough measurement step 30A.

[0027] For example, a three-dimensional point cloud of the height of the surface position of the material 1 to be measured is extracted from the rough measurement data. However, taking into consideration the error according to the resolution of the sensor, the height is set as a range (threshold) in the height direction having an upper limit and a lower limit based on the height position of the material 1 to be measured. Also, if the surface position (upper surface) of the material 1 to be measured has unevenness in the height direction, the above range in the height direction is set taking this into consideration as well.

[0028] Next, the surface shape of the material 1 to be measured is obtained from the extracted 3D point cloud. In this example, the top surface of the material 1 to be measured is obtained as the surface shape. Next, the corner positions of the obtained surface shape are obtained as the position P of each feature point (see FIG. 1). Next, feature point existence areas SA are set so as to include a range away from the obtained feature point position P by the measurement error of the sensor used for measurement. The measurement error is a value calculated from the distance between points in a three-dimensional point cloud, for example. It is preferable to set the measurement error wide enough to include a safety margin.

[0029] 3, the feature point position P' obtained in the extraction step 30B is determined from coarse information and is therefore often offset from the true feature point position P. For this reason, in consideration of the measurement error of the sensor, the feature point existence area SA is set based on the feature point position P' obtained in the extraction step 30B as a reference. This ensures that the true feature point position P is located within the set feature point existence area SA. Although the feature point existence area SA is determined from coarse information, it can be extracted as a narrow area compared to the entire top surface of the measured material 1.

[0030] [others] The area specifying step 30 is a step of performing an extraction process of a feature point existing area SA, which is an area where the position P of each feature point is estimated to exist. In other words, it is sufficient to obtain the area where the position P of the feature point exists. Therefore, the area specifying step 30 may obtain the feature point existing area SA based on information from another device. For example, when the material 1 to be measured is a material that has been cut into a desired shape by a cutting device, the region specifying step 30 may be performed as follows.

[0031] That is, the region specifying step 30 may estimate the position of the corner based on the information of the cutting position at the time of cutting, and set the feature point existence region SA. For example, information on the feature point position P' is estimated from the information at the time of cutting. Then, the feature point existence region SA is set to be an area including a range of the estimated feature point position P', which is calculated by adding a safety margin to the error of the information at the time of cutting.

[0032] The information at the time of cutting may be, for example, cutting position information sent to the cutting device or cutting position information acquired at the time of cutting. Then, the contour position of the thick plate after cutting may be estimated from the information at the time of cutting, and the position information of the corners may be acquired as the position information of the feature points from the estimated information.

[0033] Furthermore, when the workpiece 1 before being cut is the target, the characteristic point existence area SA may be identified from the transport position and transport error of a transport device such as a crane that transports the workpiece 1 to the cutting device. However, obtaining the feature point existing region SA by the rough measurement step 30A and the extraction step 30B described above makes it possible to set the feature point existing region SA smaller.

[0034] <Precision measurement process 31> The precise measurement step 31 executes a process of acquiring the surface shape of the feature point existing region SA determined in the region specifying step 30 as precise measurement data, which is a collection of three-dimensional points. This process is executed for each feature point existing region SA.

[0035] The set of three-dimensional points in the feature point existence area SA may be measured using a known sensor capable of measuring three-dimensional points, such as a laser scanner or a camera (image analysis). However, the sensor used has a higher resolution and a narrower measurement range than the sensor for the three-dimensional points used in the rough measurement process 30A.

[0036] <Feature point position calculation process 32> The feature point position calculation step 32 performs processing to obtain information on the positions P of feature points present in the feature point existence area SA from the acquired precise measurement data (see FIG. 3). The calculation of the feature point positions P is performed for each feature point existence area SA.

[0037] For example, a three-dimensional point cloud of the height of the surface position of the measured material 1 is extracted from the precision measurement data. However, the height is set as a height range (threshold) that sets the error between the upper and lower limit values ​​for the height of the measured material 1, taking into account the error according to the resolution of the sensor. Also, if the surface position (top surface) of the measured material 1 has unevenness in the height direction, the above height range is set taking this into consideration. However, since the feature point existence area SA is narrow and is a corner area, the unevenness may be ignored.

[0038] Next, the surface shape in the feature point existence area SA of the measurement target material 1 is obtained from the extracted three-dimensional point group. Next, the corner positions of the obtained surface shape are obtained as the positions P of each feature point. By narrowing the measurement range and performing sensing with high resolution, the position P of the feature point can be found with high accuracy.

[0039] <Dimension calculation process 33> In the dimension calculation step 33, a process is performed to calculate the dimensions of the measured material 1 from information on the positions P of two or more characteristic points obtained in the characteristic point position calculation step 32. In this embodiment, for example, the width and longitudinal length of the thick plate (measured material 1) to be measured are obtained as the dimensions of the measured material 1. The dimension calculation step 33 may obtain profile information, which is information on the outer peripheral contour shape of the workpiece 1 to be measured.

[0040] <About rough measurement process 30A and precise measurement process 31> Each measurement in the rough measurement step 30A and the precise measurement step 31 is performed using a measurement sensor. For example, in the rough measurement step 30A, rough measurement data is obtained using a rough measurement sensor (an example of a first measurement sensor) capable of measuring the entire surface shape of the measured workpiece 1. Also, for example, in the precise measurement step 31, precise measurement data is obtained using a precise measurement sensor (an example of a second measurement sensor) that has a narrower measurement range and higher resolution than the rough measurement sensor.

[0041] (shape measuring device) The shape measuring device is a device that realizes the above-mentioned shape measuring method. In this embodiment, an example is given of a case in which a thick plate transported to cutting equipment is cut by a cutting device to manufacture a product, and the shape of the thick plate is measured by a shape measuring device at least either before or after cutting.

[0042] The purpose of measuring the shape of the thick plate before cutting is to obtain the position P of the characteristic point of the placed thick plate, thereby obtaining the placement position of the thick plate to be cut. Then, based on the obtained placement position of the thick plate, the thick plate is cut into the target shape by a cutting device.

[0043] Furthermore, the purpose of measuring the shape of the cut thick plate is to obtain the dimensions of the cut thick plate and thereby to confirm whether or not it has been cut to the target dimensions.

[0044] The shape measuring device of this embodiment includes a coarse measurement sensor, a precision measurement sensor, and a shape calculation unit. In this embodiment, the shape calculation unit is provided in the control device. In this embodiment, a case will be illustrated in which a rough measurement sensor and a fine measurement sensor are provided on a movable part of a cutting device.

[0045] <Cutting device> The cutting device of this embodiment is, for example, a gate-type cutting device, which cuts and processes a thick plate into a target shape by, for example, gas cutting.

[0046] 4, the cutting device 2 of this embodiment includes two rails 3, a gate-shaped carriage 21, a width direction drive unit 22 provided on the carriage 21, and a control device 23. A cutter (not shown) is provided on the width direction drive unit 22, and is capable of cutting a thick plate placed in an area ARA within the two rails 3 into a target shape.

[0047] As shown in Fig. 5, a surface plate 4 is provided in the area ARA between the rails 3, and a measurement target material 1 made of a thick plate is placed in a horizontal position on the surface plate 4. For ease of understanding, the surface plate 4 is omitted in Fig. 4.

[0048] In this embodiment, when the workpiece 1 is cut by the cutting device 2 to manufacture a product, the placement position and dimensions of the workpiece 1 are automatically measured by the shape measuring device at least either before or after cutting.

[0049] 4, the shape measuring device has a rough measurement sensor 5 provided on a carriage 21 (portal frame) of the portal cutting device 2, a precision measurement sensor 6, and a shape calculation unit in the control device 23. In this embodiment, the precision measurement sensor 6 is disposed below the rough measurement sensor 5, that is, closer to the workpiece 1 to be measured.

[0050] As shown in Fig. 4, the cart 21 can run on a pair of rails 3 laid in the x-axis direction (horizontal direction: approximately the longitudinal direction of the material 1 to be measured) by means of wheels (not shown). The material 1 to be measured is placed on a surface plate 4 (omitted in Fig. 4) provided between the rails 3. The cart 21 is also provided with a width direction drive unit 22 that can move linearly in the y-axis direction (horizontal direction perpendicular to the x-axis direction: approximately the width direction of the material 1 to be measured). The width direction drive unit 22 can be driven by a known linear motion device such as a ball screw device.

[0051] <Rough measurement sensor 5 and precise measurement sensor 6> The rough measurement sensor 5 and the precise measurement sensor 6 are attached to a width direction drive unit 22 of the carriage 21 . The rough measurement sensor 5 is a sensor that is less expensive (has lower resolution) and has a wider measurement range than the precise measurement sensor 6, and is capable of measuring the three-dimensional surface shape of the entire width direction of the material 1 to be measured. In this embodiment, the rough measurement sensor 5 can be exemplified by a TOF type LiDAR sensor as an example. The rough measurement sensor 5 irradiates the material 1 to be measured with laser light that extends over the entire width direction (y-axis direction) of the material 1 to be measured, and measures the distance to the material 1 to be measured by measuring the time it takes for the reflected light to return. The rough measurement sensor 5 is moved in the x-axis direction along the rail 3 by the cart 21 to measure the three-dimensional surface shape of the entire material 1 to be measured.

[0052] The precise measurement sensor 6 has a narrower measurement range than the rough measurement sensor 5, but has a higher resolution and is capable of measuring with high accuracy. In this embodiment, the precise measurement sensor 6 can be, for example, a non-contact distance sensor using a light cutting method. The precise measurement sensor 6 irradiates the material 1 to be measured with a sheet-like laser light, and captures an image of the position of the laser light from a different angle with a camera, thereby partially measuring the three-dimensional surface shape of the material 1 to be measured.

[0053] Here, in this embodiment, a case will be described where the surface shape of the measured material 1 is roughly measured by the rough measurement sensor 5 and precisely measured by the precise measurement sensor 6. However, for example, the same type of sensor may be used as the rough measurement sensor 5 and the precise measurement sensor 6, or a configuration may be adopted in which one sensor performs both rough measurement and precise measurement. Specifically, for example, a stereo camera is used as the rough measurement sensor 5 and the precise measurement sensor 6. Then, for example, the angle of view of the stereo camera is widened (reduced resolution) to roughly measure the entire measured material 1, and then the angle of view of the stereo camera is narrowed (reduced resolution) to precisely measure parts of the measured material 1.

[0054] <Control device 23> In this embodiment, the control device 23 is provided on the cart 21. The control device 23 includes a cutting control unit 23A and a shape calculation unit 24, as shown in FIG.

[0055] The cutting control unit 23A performs a process of cutting the workpiece 1 into a target shape while driving the carriage 21 and the width direction driving unit 22 based on the acquired dimensional shape and cut shape information.

[0056] 6, the shape calculation unit 24 includes an area specification unit 24A, a precision measurement unit 24B, a feature point position calculation unit 24C, and a dimension calculation unit 24D. The area specification unit 24A of the present embodiment includes a rough measurement unit 24Aa and an extraction unit 24Ab.

[0057] The measurement data acquired by the coarse measurement sensor 5 and the precise measurement sensor 6 are supplied to a shape calculation unit 24 of the control device 23. An extraction unit 24Ab extracts a feature point existence area SA of the measured material 1 from the coarse measurement data acquired by the coarse measurement sensor 5. A dimension calculation unit 24D calculates the dimensions of the measured material 1 from the precise measurement data acquired by the precise measurement sensor 6.

[0058] The area specifying unit 24A executes the process of an area specifying step 30. The precise measurement unit 24B executes the process of a precise measurement step 31. The feature point position calculation unit 24C executes the process of a feature point position calculation step 32. The dimension calculation unit 24D executes the process of a dimension measurement step.

[0059] That is, based on the measurement information from the rough measurement sensor 5, the area identification unit 24A performs a process of acquiring two or more feature point existence areas SA, which are areas in which the position P of a feature point that identifies the shape of the measured material 1 to be measured is estimated to exist.

[0060] The precise measurement unit 24B performs a process of acquiring the surface shape of the feature point existence area SA determined by the area identification unit 24A as precise measurement data, which is a collection of three-dimensional points, for each feature point existence area SA based on the measurement information of the precise measurement sensor 6. That is, the precise measurement unit 24B performs sensing for each feature point existence area SA using the precise measurement sensor 6, and obtains precise measurement data consisting of a collection of three-dimensional points as three-dimensional position information of the surface shape in each feature point existence area SA.

[0061] The feature point position calculation section 24C determines, for each feature point existing region SA, information on the position P of the feature point existing in the corresponding feature point existing region SA from the acquired precise measurement data.

[0062] The dimension calculation unit 24D calculates the shape of the measured material 1 from the information on the positions P of the two or more characteristic points thus obtained. In the dimension calculation unit 24D of this embodiment, the width and length of the measured material 1 or the profile (peripheral contour shape) of the measured material 1 is obtained from the positions P of the four characteristic points. In other words, it is possible to obtain information on the shape of the measured material 1 itself and information on the position of the measured material 1.

[0063] <Rough measurement section 24Aa> Based on the measurement values ​​from the rough measurement sensor 5, the rough measurement unit 24Aa acquires the surface shape of the workpiece 1 as rough measurement data, which is a collection of three-dimensional points.

[0064] 7, the rough measurement unit 24Aa of this embodiment irradiates a rough measurement range D1 with laser light from the rough measurement sensor 5 attached to the width direction drive unit 22, and measures the distance to an object including the measured material 1. The rough measurement unit 24Aa sets the entire range between the rails 3 as the rough measurement range D1, and measures the shape of the measured material 1 placed between the rails 3. The rough measurement sensor 5 acquires the vertical distance to an object including the measured material 1 at a predetermined sampling period while the cart 21 moves in the x-axis direction (extension direction of the rails 3) from the rough measurement start position 3A to the rough measurement end position 3B.

[0065] <Extraction part 24Ab> The extraction unit 24Ab performs a process of extracting a feature point existence region SA in the measurement target 1 from the rough measurement data acquired by the rough measurement unit 24Aa.

[0066] The extraction unit 24Ab of this embodiment extracts information for identifying the feature point existence region SA by the procedure of steps ST1 to ST5 shown in Fig. 8, and extracts four feature point existence regions SA from the extracted information. Then, in step ST6, a movement path of the precision measurement sensor 6 for precisely measuring the four feature point existence regions SA is generated.

[0067] First, in step ST1, rough measurement data is acquired. Next, in step ST2, in order to extract the planar area of ​​the top surface of the material to be measured 1 (the area of ​​the shape of the top surface of the material to be measured 1), threshold values ​​are set for each of the x-, y-, and z-axis directions of the rough measurement data, and the point cloud that exists within the threshold values ​​is trimmed.

[0068] 9(a), for example, a lower limit value zmin and an upper limit value zmax in the height direction are set for the z-axis direction, and only the points in the range from zmin to zmax are extracted. This removes the measurement data of the surface plate 4, etc.

[0069] Next, in step ST3, noise is removed from the roughly measured data trimmed in step ST2. Specifically, as shown in FIG. 9(b), a discrete point group, that is, a set N1 of points in which the distance between points is greater than a preset threshold, is removed as noise.

[0070] Next, in step ST4, a planar region that defines the flat upper surface of the measurement object 1 is detected from the rough measurement data from which noise has been removed in step ST3. Specifically, as shown in Fig. 9(c), a set of points that match the equation (model equation) "ax+by+cz+d=0" of an arbitrary plane is obtained from the point cloud of the rough measurement data from which noise has been removed in step ST3. This allows the point cloud N2 outside the plane region to be removed as noise.

[0071] Here, since the top surface of the material to be measured 1 is a horizontal or approximately horizontal surface, it is sufficient to set the equation (model equation) of any plane, "ax+by+cz+d=0", so that the surface is horizontal or approximately horizontal. In addition, in this embodiment, an example is given of the case where the top surface of the material to be measured 1 is flat, but if the top surface is curved, it is sufficient to set an equation of the surface that defines the curved surface and obtain a group of points on the top surface of the material to be measured 1.

[0072] Next, in step ST5, the coordinates of the corners of the planar area detected in step ST4 are detected. Specifically, as shown in FIG. 9(d), the outermost part of the group of points constituting the planar region is identified, and the coordinates of the four vertices of the planar region and the edges around the vertices are calculated as "corners." This identifies the position P of the feature point determined from the rough measurement (rough information).

[0073] In this embodiment, as shown in Fig. 9(d), the range of (L / 2) in the x-axis direction from the position P of the feature point is set as the feature point existence area SA. Note that the width in the y-axis direction of the feature point existence area SA is set to a constant fixed value. That is, in this embodiment, the coordinates of the position P of the feature point are set as variables for each feature point existence area SA.

[0074] Next, in step ST6, a movement path of the precision measurement sensor 6 that passes through the four feature point existence areas SA defined by the coordinates of the corners detected in step ST5 is generated. In this embodiment, as described above, the range of each feature point existence area SA is the range of measurement length L in the x-axis direction centered on the coordinates of each corner, as shown in Fig. 9(d). Also, in this embodiment, the width of the feature point existence area SA in the y-axis direction is set to the sensor width D2 of the precision measurement sensor 6 (see Fig. 10(b)).

[0075] In this embodiment, as shown in Fig. 10(b), each feature point existence area SA is defined by two reference points (white circle positions Q in Fig. 10(b)) spaced apart by (L / 2) in the x-axis direction from the position P' of the feature point determined by each rough measurement. Then, as shown in Fig. 10(b), a path K that moves through the four feature point existence areas SA is generated so as to pass through each of the reference points Q.

[0076] <Precision measurement section 24B> The precise measurement unit 24B obtains the surface shapes of the four feature point existing regions SA among the planar regions extracted by the extraction unit 24Ab as precise measurement data that is a set of three-dimensional points. In this embodiment, as shown in Figure 10, laser light is emitted from a precision measurement sensor 6 attached to the width direction drive unit 22 in a precision measurement range D2, and the distance to an object including a corner of the measured material 1 is measured by imaging the irradiation position of the laser light.

[0077] Specifically, the movement of the carriage 21 and the width direction drive unit 22 is controlled as shown by the arrows in FIG. 10(b) so that the center of the precision measurement range D2 of the precision measurement sensor 6 moves along the path K obtained in step ST6. At this time, the precision measurement sensor 6 supplies the measurement values ​​measured while the precision measurement range D2 moves between the two reference points Q to the shape calculation unit 24. In this way, four feature point existence areas SA are each measured over the measurement length L. As described above, in this embodiment, each feature point existence area SA is defined by two reference points Q spaced apart by the measurement length L.

[0078] <Feature point position calculation unit 24C, dimension calculation unit 24D> In the characteristic point position calculation section 24C and the dimension calculation section 24D, in steps ST10 to ST15 shown in FIG. 11, the precise positions P of the characteristic points are detected, and the dimensions of the measurement object 1 are calculated from the precise positions P of the characteristic points.

[0079] Here, steps ST10 to ST14 are processes performed by the feature point position calculation section 24C, and the process of step ST15 corresponds to the process performed by the dimension calculation section 24D. The processes in steps ST10 to ST14 are similar to those in steps ST1 to ST5, respectively, and therefore will not be described in detail.

[0080] However, the process is performed for each feature point existence region SA instead of the entire surface shape of the upper surface of the measured material 1. That is, for each feature point existence region SA, a planar region is detected again based on the precise measurement data, and the coordinates of the corners (vertices and edges) of the planar region are precisely calculated again.

[0081] Then, in step ST15, which is the processing of the dimension calculation unit 24D, the distance between the coordinates of the corners is calculated, and the dimension in the length direction and the dimension in the width direction of the material to be measured 1 are calculated from this distance. The "distance between the coordinates of the corners" may be the distance between the vertices, or the distance between the edges around the vertices.

[0082] (Product manufacturing method) In this embodiment, when a workpiece 1 is cut by a gate-type cutting device 2 to manufacture a product, shape measurement is performed at least either before or after cutting using the shape measurement method using the shape measuring device described above.

[0083] According to the above configuration, when measuring the shape of the workpiece 1, the placement position and approximate surface shape of the workpiece 1 are preliminarily rough measured using the rough measurement sensor 5 with a wide measurement range. Next, based on the rough measurement data, the dimensions and placement position of the workpiece 1 are measured using the precision measurement sensor 6 with high resolution. Therefore, the dimensions of the workpiece 1 can be measured automatically without relying on human labor.

[0084] In addition, in this embodiment, the measurement accuracy of the dimensions can be improved compared to the case where the dimensions of the measured material 1 are measured only by a wide-area sensor with low resolution. On the other hand, in this embodiment, the placement position of the measured material 1 can be efficiently identified and the dimensions of the measured material 1 can be measured compared to the case where the dimensions of the measured material 1 are measured only by a narrow-area sensor with high resolution.

[0085] Furthermore, by measuring the dimensions of the workpiece 1 before and after cutting, it is possible to manufacture products with high dimensional accuracy.

[0086] (others) The present disclosure may also have the following configuration. (1) A shape measuring method for measuring the shape of a workpiece, comprising the steps of: a region specifying step of acquiring two or more feature point existing regions which are regions in which feature points that specify the shape of the workpiece to be measured are estimated to exist; a precision measurement step of acquiring the surface shape of each of the identified feature point regions as precision measurement data consisting of a set of three-dimensional points; a feature point position calculation step of determining position information of the feature points present in each feature point existence region from the obtained precise measurement data; A method for measuring the shape of a workpiece, comprising: (2) A dimension calculation step of calculating dimensions of the workpiece from the obtained position information of two or more characteristic points. (3) The region specifying step a rough measurement step of acquiring the surface shape of the workpiece as rough measurement data consisting of a set of three-dimensional points; an extraction step of extracting two or more feature point existing regions from the rough measurement data acquired in the rough measurement step; Equipped with. (4) in the rough measurement step, the rough measurement data is acquired using a first measurement sensor capable of measuring the overall surface shape of the workpiece; In the precision measurement step, the precision measurement data is obtained using a second measurement sensor having a narrower measurement range and higher resolution than the first measurement sensor. (5) The material to be measured is a plate material, In the extraction process, a planar area of ​​the upper surface of the measured material is extracted from the rough measurement data, the positions of two or more feature points are estimated from the extracted planar area, and areas including the positions of each estimated feature point are extracted as the feature point existence areas. (6) The material to be measured is a polygonal plate material, The feature points are the positions of the corners of the polygonal shape. (7) The material to be measured is a material cut into a desired shape by a cutting device, In the region specifying step, a feature point existence region is specified based on information on the cutting position at the time of the cutting. (8) A shape measuring device for measuring the shape of a workpiece, comprising: an area specifying unit for obtaining two or more feature point existing areas which are areas in which feature points that specify the shape of the workpiece to be measured are estimated to exist; a precision measurement unit that acquires the surface shape of each of the acquired feature point existing regions as precision measurement data consisting of a set of three-dimensional point clouds; a feature point position calculation unit that calculates position information of the feature point that exists in the corresponding feature point existence region from the obtained precise measurement data; Equipped with. (9) A dimension calculation unit is provided that calculates the dimensions of the workpiece from the position information of the two or more characteristic points thus obtained. (10) The region specifying unit a rough measurement unit that acquires the surface shape of the workpiece as rough measurement data consisting of a set of three-dimensional points; an extraction unit that extracts two or more feature point existence regions from the rough measurement data acquired by the rough measurement unit; Equipped with. (11) The rough measurement unit acquires the rough measurement data using a first measurement sensor capable of measuring an entire surface shape of the workpiece, The precision measurement unit acquires the precision measurement data using a second measurement sensor that has a narrower measurement range and higher resolution than the first measurement sensor. (12) The material to be measured is a material cut into a desired shape by a cutting device, The first measurement sensor and the second measurement sensor are mounted on the cutting device. (13) A method for manufacturing a product by processing the test material, comprising the steps of: The shape of at least one of the workpieces before and after processing is measured by the shape measuring device of the present disclosure; How the product is manufactured. EXAMPLES

[0087] The surface shape of the thick plate was measured using the shape measuring device described in the embodiment. The thick plate used was a rectangular steel plate measuring 1215 mm in width and 4375 mm in length. The rough measurement sensor 5 was a LIDAR sensor that measures the shape of an object using a TOF method, and the precise measurement sensor 6 was a laser profiler that measures the shape of an object using a light-section method.

[0088] As a result, it was confirmed that the four feature point existence areas SA and the movement path K of the precision measurement sensor were successfully generated. Furthermore, when the precise measurements of a thick plate taken using the device of this embodiment were compared with the longitudinal and transverse dimensions measured manually with a tape measure, it was found that the maximum error with the manual measurements was 1.8 mm, indicating that the dimensions could be calculated with high precision. [Explanation of symbols]

[0089] 1 Material to be measured 2 Cutting device 3. Rail 5 Coarse measurement sensor 6 Precision measurement sensors 21 Trolley 22 Width direction drive unit 23 Control device 23A Cutting control section 24 Shape calculation section 24A Area identification part 24Aa Rough measurement section 24Ab extraction part 24B Precision measurement section 24C Feature point position calculation unit 24D Dimension Calculation Section 30 Area identification process 30A rough measurement process 30B Extraction process 31 Precision measurement process 32 Feature point position calculation process 33 Dimension calculation process D1 Rough measurement range D2 Precision Measurement Range K pathway Q reference point SA feature point existence area

Claims

1. A shape measuring method for measuring a shape of a workpiece, comprising the steps of: a region specifying step of acquiring two or more feature point existing regions which are regions in which feature points that specify the shape of the workpiece to be measured are estimated to exist; a precision measurement step of acquiring the surface shape of each of the identified feature point existing regions as precision measurement data consisting of a set of three-dimensional points; a feature point position calculation step of determining position information of the feature points present in each feature point existence region from the obtained precise measurement data; A method for measuring the shape of a workpiece, comprising:

2. a dimension calculation step of calculating dimensions of the workpiece from the position information of the two or more characteristic points obtained; 2. A method for measuring the shape of a workpiece according to claim 1, comprising:

3. The region specifying step includes: a rough measurement step of acquiring the surface shape of the workpiece as rough measurement data consisting of a set of three-dimensional points; an extraction step of extracting two or more feature point existing regions from the rough measurement data acquired in the rough measurement step; 2. A method for measuring a shape of a workpiece according to claim 1, comprising:

4. In the rough measurement step, the rough measurement data is acquired using a first measurement sensor capable of measuring the overall surface shape of the workpiece; In the precision measurement step, the precision measurement data is acquired using a second measurement sensor having a narrower measurement range and higher resolution than the first measurement sensor.

4. A method for measuring the shape of a workpiece according to claim 3.

5. The material to be measured is a plate material, In the extraction step, a planar region of the upper surface of the workpiece is extracted from the rough measurement data, positions of two or more feature points are estimated from the extracted planar region, and regions including the positions of the estimated feature points are extracted as the feature point existence regions.

4. A method for measuring the shape of a workpiece according to claim 3.

6. The material to be measured is a polygonal plate material, The feature points are positions of corners of a polygonal shape. A method for measuring the shape of a workpiece according to claim 1.

7. The material to be measured is a material cut into a desired shape by a cutting device, In the region specifying step, a feature point existence region is specified based on information on a cutting position at the time of the cutting. A method for measuring the shape of a workpiece according to claim 1.

8. A shape measuring device for measuring the shape of a workpiece, comprising: an area specifying unit that obtains two or more feature point existing areas that are areas in which feature points that specify the shape of the workpiece to be measured are estimated to exist; a precision measurement unit that acquires the surface shape of each of the acquired feature point existing regions as precision measurement data consisting of a set of three-dimensional points; a feature point position calculation unit that calculates position information of the feature point that exists in the corresponding feature point existence region from the obtained precise measurement data; An apparatus for measuring the shape of a workpiece comprising:

9. 9. The device for measuring the shape of a workpiece according to claim 8, further comprising a dimension calculation section for calculating dimensions of the workpiece from the position information of the two or more characteristic points thus obtained.

10. The region specifying unit is a rough measurement unit that acquires the surface shape of the workpiece as rough measurement data consisting of a set of three-dimensional points; an extraction unit that extracts two or more feature point existence regions from the rough measurement data acquired by the rough measurement unit; 9. The device for measuring the shape of a workpiece according to claim 8, further comprising:

11. the rough measurement unit acquires the rough measurement data using a first measurement sensor capable of measuring the overall surface shape of the workpiece; the precision measurement unit acquires the precision measurement data using a second measurement sensor having a narrower measurement range and higher resolution than the first measurement sensor; 11. The shape measuring device for a workpiece according to claim 10.

12. The material to be measured is a material cut into a desired shape by a cutting device, The first measurement sensor and the second measurement sensor are installed on the cutting device.

12. The shape measuring device for a workpiece according to claim 11.

13. A method for manufacturing a product by processing the material to be measured, The shape of at least one of the workpiece before and after processing is measured by the shape measuring device according to any one of claims 8 to 12. How the product is manufactured.

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