KR20220157826A - the method for successively efficiently processing the cut sub-process of the multi-phase of the improvement processing using the image sensor - Google Patents

Abstract

The present invention relates to a method for successively and efficiently processing a cut sub-process of multiple steps of improvement processing using an image sensor. A plasma cutting device may successively and efficiently perform a cut sub-process of multiple steps of improvement processing. At the first cut sub-process, according to an NC program, a product (34) is cut from a parent material on a stage. Next, the image of an area near the regular location of each of the two corner points of the cut product (34) (the locations of the corner points of a product figure (80) which is defined by the NC program) (861, 862) is filmed by an image sensor, such that the actual locations (841, 842) of the two corner points of the product (34) may be detected from the filmed image. Therefore, the parallel moving distance and the rotation angle between the detected actual locations (841, 842) and the regular locations (861, 862) may be calculated. In addition, the NC program may be corrected to be suitable to the actual location of the product (34) according to the calculated parallel moving distance and rotation angle. In the next cut sub-process, according to the corrected NC program, an additional cutting is performed for improvement processing on the cutting surface on the outer circumference of the product (34). Consequently, the cut sub-processes can be successively and efficiently performed.

Description

{the method for successively efficiently processing the cut sub-process of the multi-phase of the improvement processing using the image sensor}

The present invention relates to a method for continuously and efficiently processing a multi-step sub-cutting process of improvement processing using an image sensor.

Generally, it relates to automatic cutting devices for cutting products from base materials using plasma cutting torches, laser cutting torches, gas cutting torches or other cutting tools.

Among products cut by plasma cutting, laser cutting, gas cutting, or other cutting methods, improvement processing or chamfering processing on the cut surface of the outer circumference of the product to improve the quality of welding to be performed later or for other purposes ( Hereinafter, both are collectively referred to as "improvement processing") in many cases where it is required to form.

For example, in the case of products used as parts of the body or frame of a construction machine, improvement processing is required for about 70% of the products. Improvement processing is divided into many types according to the shape of the processing surface, and according to some types of improvement processing among them, the improvement processing surface is composed of a combination of two cut surfaces having different angles with respect to the main surface of the product.

This kind of refinement is performed by a two-step sub-cutting process to form two cut surfaces, respectively.

In the first step of the sub-cutting process, the base material is cut in a direction, for example, perpendicular to the main surface of the base material, and the product is cut out from the base material. In the sub-cutting step of the second step, a bevel cut is made on the outer contour of the cut product, for example in an oblique direction, with respect to the main surface of the product, and a part of the outer edge is cut off.

Regarding improvement processing, inventions described in US Patent No. 6,326,588 (Patent Document 1) and Japanese Unexamined Patent Publication No. 11-57999 (Patent Document 2) are known.

US Patent No. 6,326,588 discloses a method of performing a two-step cutting for improvement machining. This method first cuts the base material vertically with a laser beam to cut out the product, then removes the scraps leaving only the product, then detects the outer position of the product, and transfers the detected outer position to the laser control unit Finally, the outer edge of the product is obliquely cut using an inclined laser beam.

Japanese Unexamined Patent Publication No. 11-57999 discloses the following improved cutting device. That is, this improved cutting device receives a pre-cut product, places it at a predetermined position, and detects the positions of a plurality of points on the outer shape of the product using a laser sensor or the like. Based on the positions of the plural points of the detected outline, geometric shape data that completely defines the outline of the product as a combination of straight lines, circles, arcs, etc. is generated. Using the geometry data, the outline of the product is cut at an arbitrary inclination angle.

Further, although not directly related to improvement processing, Japanese Unexamined Patent Publication No. 2003-251464 (Patent Document 3) discloses a method for making the cutting position accurate when cutting out a product from a base material. Two types of methods are disclosed here. In the first method, a base material is photographed with a camera, contour coordinates of the base material are calculated from the photographed image, and a product figure is nested within a cutable region within the calculated contour of the base material. In the second method, the data of the size or shape of the base material and the size or shape of the figure to be cut are stored in advance, and various points of the base material are photographed with a camera to calculate the outline of the base material at each shooting point, and the outline and After comparing the data of the base material stored in advance and adjusting the positional displacement of both data, the product is then cut out.

In order to improve the working efficiency of the improvement process, the sub-cutting process having the above two or more steps is continuously and automatically performed using one cutting device capable of automatically controlling the cutting position by numerical control (NC). It is desired to be able to However, in the sub-cutting process of the first stage, high-precision machining can be performed in which the performance of the NC is reflected, but there is a problem that the cutting precision deteriorates in the sub-cutting process of the second and subsequent stages. The reason for this is that, when the product is cut from the base material in the initial stage, the product that is not supported by the base material moves, and the position of the product relative to the cutting device is slightly displaced from the original position.

U.S. Patent No. 6,326,588 and Japanese Laid-Open Patent Publication No. 11-57999 provide a method of sensing the outer position of a product and calculating the outer line of the product from the sensing result.

However, in order to accurately calculate the outline of the product, it is necessary to sense the positions of many points on the outline of the product. Then, a large amount of calculation processing must be performed in order to calculate the geometric shape data that completely defines the outer shape of the product from these detection results. In addition, when detecting the position of the outer shape of a product, scraps other than the product are removed in advance, as in US Patent No. 6,326,588, or only the product is taken out and set in a cutting device, as in Japanese Patent Laid-Open No. 11-57999. Needs to be. For this need, a considerably long waiting time must be intervened between the cutting subprocess of the first stage and the subcutting subprocess of the next stage, and therefore, it is difficult to efficiently proceed these two subcutting steps continuously. .

According to the present invention, a method for continuously and efficiently processing multiple steps of sub-cutting process of improved machining using an image sensor includes a stage for placing a base material, a cutting tool, and an image sensor having an imaging area, and the cutting tool for the stage. The cutting tool, the image sensor, and the tool moving mechanism respectively operate according to the NC program and the tool moving mechanism for moving the cutting tool, changing the angle of the cutting tool, and moving the imaging area of the image sensor. Equipped with a controller to control. The controller includes first cutting sub-process control means for performing control to execute a first sub-process of cutting in which the base material placed on the stage is cut by the cutting tool to cut out a product according to the NC program; After the first cutting subprocess is executed, setting the imaging area of the image sensor to one or more areas including regular positions defined by the NC program of two or more singular points of the cut product on the stage, and image pickup control means for performing control to acquire images of the one or more regions from the image sensor, and analyzing the images of the one or more regions acquired from the image sensor to obtain the two or more elements of the cut-out product on the stage; Singular point detecting means for detecting the actual position of the singular point, and program correcting means for modifying the NC program to conform to the actual position of the cut product on the stage according to the detected actual position of the singular point, and the corrected NC program Accordingly, it has second cutting sub-process control means for controlling to execute a second sub-cutting process of performing additional cutting by the cutting tool on the cut-out product on the stage.

According to the present invention, using a single cutting device capable of automatically controlling the cutting position by numerical control (NC), it is possible to continuously perform a sub-cutting step having two or more steps for improving processing.

1 is a perspective view showing the overall configuration of a first embodiment of the present invention applied to a plasma cutting device.
Fig. 2 is a perspective view of a tilter for tilting the plasma torch in the first embodiment;
Fig. 3 is a block diagram showing calibration of the main controller 32 in the first embodiment;
4A to 4D are cross-sectional views of cut surfaces for explaining different types of improvement processing.
Fig. 5 is a diagram showing the flow of control of a cutting process of improvement processing composed of a plurality of steps of sub-cutting process.
Fig. 6 is a plan view of the product 34 for explaining control for detecting the position of the cut product 34 and grasping its positional deviation.
Fig. 7A is a diagram showing an example of a pattern for searching for a singularity by a pattern matching method, and Fig. 7B is a diagram showing an example when a figure of a product in an image and a pattern are matched.
Fig. 8 is a plan view of the base material 14 for explaining the calibration of process control data.
Fig. 9 is a flowchart of the same calibration control;
Fig. 10 is a perspective view showing the arrangement of an image sensor and a lamp in a plasma cutting device according to a second embodiment of the present invention;
Fig. 11A is a diagram showing an example of a console when a singularity is automatically detected in the second embodiment, and Fig. 11B is a diagram showing an example of a console when a singularity is manually detected.
Fig. 12 is a diagram showing the flow of control for detecting a singular point in the second embodiment;
Fig. 13 is a diagram showing the flow of control for detecting the origin coordinates and posture of a base material in the second embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

1 shows the overall configuration of a first embodiment of the present invention.

As shown in Fig. 1, the plasma cutting apparatus 10 according to the first embodiment of the present invention has a substantially rectangular parallelepiped table 12 installed on the floor, and a base material 14 is placed on the upper surface of the table 12. (typically a steel plate) is mounted. In order to control the cutting position with respect to the base material 14, the table 12 has an X axis and a Y axis in the direction of the long and short sides of the planar shape, respectively, and in the direction orthogonal to the upper surface of the table 12 (height direction). A Cartesian coordinate system with a Z axis is logically defined. Next to the table 12, an X track 16 is installed parallel to the X axis, and a bogie 18 is mounted on the X track 16, and the bogie 18 is in the X axis direction. You can travel round trip.

A Y track beam 20 extends from the bogie 18 upward to the table 12 in parallel with the Y axis, and a carriage 22 is mounted on the Y track beam 20, and the carriage 22 It can reciprocate in the Y-axis direction. An elevator 24 is mounted on the carriage 22, and a tilter 26 is mounted on the elevator 24, and the elevator 24 can reciprocate the tilter 26 in the Z-axis direction. To the tilter 26, a plasma torch 28 as a cutting tool is mounted. The tilter 26 is capable of tilting the plasma torch 28 (changing the direction of the plasma torch 28) in a predetermined angular range required for improvement processing.

As shown in FIG. 2, the tilter 26 has a bracket 40 mounted on the elevator 24 and capable of moving up and down in the Z-axis direction, and to the bracket 40 a main rotation shaft 42 parallel to the Z-axis. ) is mounted, and the main rotating shaft 42 is free to rotate in a certain angular range around the B axis parallel to the Z axis. Further, two arms 44 and 44 extending downward in parallel to the Z axis are fixed to the main rotation shaft 42, and a sub rotation shaft 46 is sandwiched between the lower ends of the arms 44 and 44. A plasma torch 28 is mounted, and the plasma torch 28 is free to rotate with respect to the arms 44 and 44 in a certain angular range around the C axis perpendicular to the B axis. By power from the motor unit 48 mounted on the bracket 40, the rotation of the main rotation shaft 42 and the rotation of the sub rotation shaft 46 are carried out independently.

Referring again to FIG. 1, the elevator 24 is further equipped with an image sensor 30 for sensing a two-dimensional image of the surface of the base material 14 on the stage 12, and the image sensor 30 can move up and down in the Z-axis direction together with the tilter 26 (plasma torch 28). As the image sensor 30, for example, an image sensor (still image camera or moving image camera) incorporating an area image pickup device using a CCD or the like, or a linear image sensor used in a flat base type image scanner or the like. Various structures can be adopted, such as one configured to scan an imaging range with an imaging element and one that takes an infrared image, but in this embodiment, a digital moving picture camera using a CCD or the like is used as an example. In addition, the image sensor 30 may be attached to the carriage 22 instead of the elevator 24 . In any case, the image sensor 30 can move in the direction of the X axis and the Y axis together with the tilter 26 (plasma torch 28), and the image sensor 30 and the tilter 26 (of the plasma torch 28) The positional relationship in the XY plane of the basic mounting position) is constant. The field of view of the image sensor 30 is parallel to the Z axis and directed (downward) to the table 12, and the imaging optical system of the image sensor 30 is the main surface (upper surface) of the base material 14 on the table 12. It is adjusted so that an image can be formed on the light-receiving surface of the image sensor 30, and therefore, an area of any size on the main surface of the base material 14 (hereinafter referred to as an imaging area) can be photographed.

The above-described X track 16, bogie 18, Y track beam, carriage 22, elevator 24 and tilter 26 are the plasma torch 28 for the base material 14 on the stage 12 A tool moving mechanism for changing the cutting position (i.e., the position of the point at which the base material 14 is cut on the XY coordinate plane) and the cutting angle (bevel angle, i.e., the angle of the cutting plane with respect to the Z axis) by . The tool moving mechanisms 16 to 26 also serve to change the position of the imaging area of the image sensor 30 with respect to the base material 14 on the stage 12. Although not shown in FIG. 1, a plasma power supply 35 (see FIG. 3) for supplying electrical power to the plasma torch 28 and a gas system 36 for supplying plasma gas and assist gas to the plasma torch 28 (See Fig. 3) is also provided in this plasma cutting device 10.

A main controller 32 is installed near the table 12. The main controller 32 has a numerical controller 320 as shown in FIG. 3, and the numerical controller 320 inputs and stores the NC program 322 from an external device, and based on the NC program 322, the base material Execute and control the cutting process for cutting out the product 34 from 14. That is, the numerical controller 320 controls the movement and angle (bevel angle) of the plasma torch 28 by controlling the operation of the tool moving mechanisms 16 to 26 based on the stored NC program 322, The operation of the plasma torch 28 is controlled by controlling the operation of the plasma power source 35 and the gas system 36 . Here, the NC program 322 includes, for example, base material definition data defining the shape and size of the base material 14, and product figure data defining the position and shape of each product 34 on the base material 14. Included. Then, in the case where refinement processing is to be performed on each product 34, which part of each product 34 is subjected to refinement processing, and what shape the sectional shape of the processed cut surface should be, etc. Improvement processing data specifying the detailed conditions of improvement processing of , are also included in the NC program 322 . In addition, when the improvement processing of each product 34 includes a plurality of steps of sub-cutting process described below, at least two points on the outline of each product 34 selected in advance according to the shape of each product 34 (typical As, for example, the XY coordinate values of the positions of points corresponding to corners of the outer shape of the product 34 (referred to as singular points) are also included in the NC program 322 .

As will be described later with reference to FIGS. 4A-4D, some types of refinement machining are performed by a two or more step sub-cutting process. In that case, each product 34 is cut out from the base material 14 based on the NC program 322 in the cutting subprocess of a 1st stage. After that, in the sub-cutting process after the second step, the NC program 322 is used so that the cut surface of each product 34 cut out has a shape specified by the improvement processing data of the NC program 322 in cross-sectional shape. Further cutting is performed based on In the case where a plurality of sub-step cutting processes are performed in this way, when each product 34 is cut out of the base material 14 in the sub-cutting process of the first step, the position of each product 34 is set to the original position (regular position) may be slightly displaced. Positional displacement of each product 34 may occur also in each cutting substep of the second step. When the position of a certain product 34 is shifted from the normal position in the previous sub-cutting step, it becomes impossible to carry out the next sub-cutting step based on the original NC program 322. In preparation for this problem, the main controller 32 additionally detects the above-described positional displacement of each product 34 just before starting each cutting subprocess after the second step, and NC so as to compensate for the positional displacement. Control for correcting the program 322 can be performed.

In order to enable control for correcting this NC program 322, the main controller 32 has an image analyzer 324 as shown in FIG. 3, and the image analyzer 324 includes a numerical controller 320 and It is connected to the image sensor 30. The image analyzer 324 may be a computer program, a hard-wired logic circuit, or a combination thereof. The image analyzer 324 and the numerical controller 320 realize the above control by cooperating as follows. That is, immediately before starting each sub-cutting process after the second step, the numerical controller 320 moves the image sensor 30 by controlling the tool moving mechanisms 16 to 26, and then the image sensor 30 The center point of the imaging area of each coincides with the regular position of at least two singular points of each product 34 designated by the NC program 322 (the position at which the singular points are actually located there if there is no such displacement). At positions (i.e. positions just above the regular positions of the two singular points), the image sensors 30 are stopped in sequence. When the image sensor 30 stops just above the normal position of each singular point, the image analyzer 324 drives the image sensor 30 to obtain an imaging area on the circumferential surface of the base material 14 (i.e., the center of the normal position of each singular point). An image of a predetermined size) is acquired, and the acquired image is analyzed to detect the XY coordinates of the actual position of each singular point, and the XY coordinates are calculated.

The image analyzer 324 notifies the numerical controller 320 of the XY coordinate values of the actual positions of each detected singularity. For each product 34, the XY coordinate values of the actual positions of at least two singular points are detected by the image analyzer 324 and notified to the numerical controller 320. After that, the numerical controller 320 calculates the XY coordinate values of the actual positions of at least two singular points of each product 34 notified from the image analyzer 324 and each product 34 designated by the NC program 322. The XY coordinate values of the normal position of the singularity point are compared to calculate a set of values (a set of translation component values and rotation component values) representing the amount of displacement of the actual position of each product 34 from the normal position. . Then, the numerical controller 320 modifies the NC program 322 (particularly, the product figure data for each product 34) to be suitable for the actual position of each product 34 according to the set of calculated position deviation values, , the cutting sub-process of the next step is controlled based on the modified NC program 323. As can be seen from the detailed description of this control described later, according to this control, the actual position of the product 34 can be ascertained more simply than in the prior art described above. And this control can be implemented even without removing scrap (remains other than the product 34) on the table 12.

As shown in FIG. 3 , the main controller 32 further has a console 326 . In the console 326, an operator inputs various commands to the above-described numerical controller 320 and image analyzer 324, or various information (eg, an image) from the numerical controller 320 and image analyzer 324 is provided. It is used for displaying images received from the sensor 30, normal positions and detected actual positions of the singularity described above, and various text messages, etc.).

4A to 4D show examples of the cross-sectional shape of a cut surface of a product 34 by representative plural types of improvement processing that can be performed by the plasma cutting device 10 according to one embodiment of the present invention.

All of the cut surfaces of the product 34 obtained by improvement processing of the kind shown in FIG. 4A are bevel surfaces 50 that form an angle other than perpendicular to the main surface (upper surface) of the product 34. . In this way, the kind of improvement processing in which all of the cut surfaces become one bevel surface 50 is generally called V improvement processing. Incidentally, a case where the top and bottom are reversed from those in Fig. 4A is also included in the V improvement processing.

A cut surface of a product 34 obtained by improvement processing of the kind shown in FIG. 4B is a bevel surface 50 in part and a vertical surface 52 perpendicular to the main surface in the remaining part. In this way, the kind of improvement processing in which the cutting surface is composed of two surfaces, the bevel surface 50 and the vertical surface 52, is generally called Y improvement processing. Also, when the top and bottom are reversed from those in Fig. 4B, they are included in the Y improvement processing.

The cut surface of the product 34 obtained by improvement machining of the kind shown in FIG. 4C is composed of one bevel surface 50A having a positive bevel angle and another bevel surface 50B having a negative bevel angle. do. In this way, the kind of improvement processing in which the cut surface is constituted by the two bevel surfaces 50A and 50B having different bevel angles is generally referred to as X improvement processing.

A cut surface of a product 34 obtained by improvement processing of the kind shown in FIG. 4D has upper and lower beveled surfaces 50A and 50B and a central vertical surface 52 . In this way, the kind of improvement processing in which the cut surface is constituted by the three faces 50A, 50B, and 52 having different bevel angles is generally referred to as K improvement processing.

The V improvement process shown in FIG. 4A can be used in a one-step cutting step. In contrast, the Y refinement process and the X refinement process shown in FIGS. 4B and 4C require a two-step sub-cutting step, and the K-improvement process shown in FIG. 4D requires a three-step sub-cutting step. These Y, X and K improvement processes are controlled according to the principles of the present invention. Here, in the Y, X, and K improvement processing, which of the vertical plane and the bevel plane is to be formed at which stage can be freely selected. For example, in the case of the Y improvement machining shown in Fig. 4B, typically the vertical face 52 is formed in the first step and the bevel face 50 is formed in the second step, but conversely, the bevel face is formed in the first step. 50 may be formed, and the vertical surface 52 may be formed in the second step.

Fig. 5 shows the flow of control when the main controller 32 (numerical controller 320 and image analyzer 324) controls the cutting process of improvement processing composed of a plurality of sub-steps of cutting.

As shown in FIG. 5, in step 60, the numerical controller 320 in the main controller 32 executes and controls the cutting sub-process of the first step based on the inputted NC program 322. In the cutting sub-step of the first step, based on the predetermined position and posture of the base material 14 on the stage 12 and the shape figure data of each product 34 described in the NC program 322, As the plasma torch 28 moves along the shape of each product 34 while maintaining the first bevel angle, the plasma torch 28 sprays a plasma arc, whereby the entire circumference of each product 34 Each product 34 is cut from the base material 14 by cutting the base material 14 at a first bevel angle (for example, an angle perpendicular to the main surface of the base material 14 or a predetermined inclined angle) over the base material 14. Cut out. Since each cut product 34 completely separates from the base material 14, the position of each product 34 may slightly shift from the regular position. When all products 34 designated by the NC program 322 are cut out, the sub-cutting process of the first step is completed.

After the sub-step of cutting in the first step is completed, the main controller 32 controls the steps 62 to 66, that is, detects the actual position of each cut product 34 and grasps the positional displacement of each product 34. carry out control. 6 is a plan view of the product 34 for specifically explaining this control. Hereinafter, control of steps 62 to 66 will be described with reference to FIGS. 5 and 6 .

As shown in Fig. 5, in step 62, the image analyzer 324 drives the image sensor 30 to determine the regular positions of at least two singular points of each cut product 34 on the surface of the base material 14. Two regions of a predetermined size centered on each are photographed, and images of the two captured regions are acquired from the image sensor 30, and images (color images or gray scale images) of the two regions are converted into binary images ( monochrome image). Here, the singularity of each product 34 is any point or point on each product 34 suitable for calculating the location of each product 34 based on its location. At least two singular points are set for each product 34 in order to grasp the displacement (parallel movement component and rotation component) of each product 34 . The XY coordinates of the normal positions of at least two singular points of each product 34 are pre-specified by the NC program 322. Alternatively, as a modified example, based on the product figure data of each product 34 included in the NC program 322, the numerical controller 320 determines the XY coordinates of the normal positions of at least two singular points of each product 34 may decide In this embodiment, two corner points on the outline of each product 34 are used as two singular points. In addition, the "regular position" of the singularity of each product 34 is the position where the singularity must actually exist there if the positional deviation of each product 34 does not occur, and these are the positions of each product in the NC program 322 It is determined based on the product figure data of (34). Occurrence of positional displacement of the product 34 causes the actual position of the singularity to shift from its normal position.

Regarding step 62, it will be explained using an example shown in FIG. In Fig. 6, a figure of a dashed-dotted line with reference numeral 80 is a shape figure of a certain product 34, defined by product figure data of an NC program 322, and indicates the regular position of the product 34. This is hereinafter referred to as "regular product figure". Two corner points 861 and 862 on the outline of the regular product figure 80 are set as singular points of the regular product figure 80 . Since the singular points 861 and 862 of the regular product figure 80 correspond to the normal positions of the two singular points (corner points) of the product 34, these are hereinafter referred to as "singular point normal positions". In step 62, the numerical controller 320 moves the image sensor 30 along the X and Y axes so that the center of the imaging area of the image sensor 30 is located at the first singularity normal position 861. Set the position of (30). Then, the image analyzer 324 drives the image sensor 30 to acquire an image of the imaging area (ie, an area of a predetermined size centered on the first singular point normal position 861) 881 . Next, the numerical controller 320 sets the position of the image sensor 30 so that the center of the imaging area of the image sensor 30 is located at the second singular point normal position 862, and the image analyzer 324 The image sensor 30 is driven to acquire an image of the imaging area (ie, an area of a predetermined size centered on the second singularity normal position 862) 882 . Here, since the XY coordinates of the normal positions 861 and 862 of the singularity are determined based on the NC program 322, the position of the center of the imaging area of the image sensor 30 is set to the normal position of the singularity 861 and 862 as described above. ) is performed based on the NC program 322. When the image sensor 30 captures the provisional imaging areas 881 and 882, the scrap 82 along with the product 34 is also placed on the stage 12 in the same position when the first stage sub-cutting process is finished. may be left in Of course, you may remove the scrap 82 on the stage 12, leaving only the product 34, before shooting.

In many cases, the actual position of the cut-out product 34 is slightly deviated from the regular product figure 80 as shown, and thus the actual positions 841 and 842 of the two singular points of the product 34 correspond to The singularity to deviates from the normal position (861, 862). In most cases, the displacement distance is about 1 mm at most. The size of the imaging areas 881 and 882 is set sufficiently larger than the position shift amount. Therefore, the actual positions 841 and 842 of each singularity are necessarily included in each imaging area 881 and 882 .

Referring again to FIG. 5 , after acquiring the binary images of the imaging areas 881 and 882 in step 62 described above, in step 63 the image analyzer 324 analyzes the binary images of the imaging areas 881 and 882, The actual positions (841, 842) of the two singular points are found, and the XY coordinates of the actual positions (841, 842) are calculated. The range in which the actual positions 841 and 842 of the singularity are searched may be the entire range of the imaging areas 881 and 882, but otherwise, as illustrated in FIG. It may be limited only within the vicinity ranges (901, 902) within the distance R. Here, as the predetermined distance R, a value about the maximum value of the possible misalignment distance (for example, the maximum width of the cutting groove, i.e., the gap between the cut product 34 and the scrap 82) is employed and obtained. In this way, by limiting the search range for the actual position (841, 842) of the singularity only within the range (901, 902) in the vicinity of the normal position (861, 862) of the singularity, scrap (82) existing around the product (34) ) is excluded from the search range in many cases, the possibility of erroneously detecting a certain point of the scrap 82 as a singular point is reduced. In addition, when a plurality of candidate points with an equally high probability of corresponding to the same singular point are found through the search, one point located closest to the normal position of the corresponding singular point is selected from among the plurality of candidate points found. can be selected as the actual location of

As a modified example, instead of sequentially acquiring images of the two regions 881 and 882 each containing the two singular point normal positions 861 and 862 and analyzing each image as described above, two singular point normal positions Even if an image of one large area including both the positions (861, 862) is acquired at one degree, and then the image of one large area is analyzed to find the actual positions (841, 842) of the two singular points. do.

As an image analysis method for finding the actual position of a singular point, various methods can be employed. For example, in each image of the imaging areas 881 and 882, a plurality of line segments constituting the outline of the product 34 are detected, and each singular point normal position as a corner point formed by crossing those line segments ( 861, 862) may be found, and a method of considering the found corner point as the actual position of the singular point may be adopted. Alternatively, for example, the pattern matching method shown in Figs. 7A and 7B can be used. This method is a method of finding a figure pattern that most closely matches a product shape pattern in the vicinity of each singularity point determined by the product figure among the respective images of the areas 881 and 882.

7A shows a pixel value matrix 100 used in this pattern matching method. This pixel value matrix 100 has a size of M pixels x N pixels (in Fig. 7A, one column corresponds to one pixel, so in the illustrated example, the size of the pixel value matrix 100 is 8 pixel × 8 pixels). Each pixel value in the pixel value matrix 100 is a binary value of "1" or "0". The pixel value matrix 100 is composed of a product area 102 and a background area 104, all pixel values of the product area 102 are, for example, "1", and all pixel values of the background area 104 are, for example, For example, it is "0". The shape of the product area 102 corresponds to the shape of the part in the vicinity of the normal position 861 of the singularity of the product figure of a certain product 34 defined by the product figure data of the NC program, and the shape of the background region 104 is , corresponds to the shape of the area outside the product figure (typically, the area of the cut portion). Then, one corner point 106 corresponding to the normal position 861 of the singularity point in the product area 102 is arranged at the center point of the pixel value matrix 100 .

The image analysis unit 324 receives the product figure data of the NC program from the numerical controller 320, and based on the product figure data, a certain singular point normal position of each product 34, for example, a first singular point normal position The pixel value matrix 100 having the above configuration corresponding to (861) is created. After that, the image analyzer 324 overlays the pixel value matrix 100 on one part of the binary image of the imaging area 881 of the first singular point normal position 861 .

At that time, first, the center point of the binary image (namely, the first singular point normal position 861) and the center point of the pixel value matrix 100 (namely, the corner point 106 of the product area 102 shown in Fig. 7A) The pixel value matrix 100 is overlaid so as to positionally coincide with each other. Then, the image analyzer 324 compares the pixel value of each pixel in the pixel value matrix 100 with the pixel value of each pixel in the binary image overlaid with the pixel value, checks whether both pixel values match, and matches the pixel values. Count the number of pixels obtained. This aggregate value represents the degree of match of the image pattern between the pixel value matrix 100 and the portion of the binary image over which it is overlaid. After that, the image analysis unit 324 sequentially moves the position of the center point of the pixel value matrix 100 on the binary image in the X direction or the Y direction one pixel at a time, and obtains the above-described pixel value at each movement destination position. By performing comparison, the number of pixels with identical pixel values is counted and a degree of matching is obtained. The movement of the center point of the pixel value matrix 100 is repeated over all pixel positions in the above-described search range, and the number of pixels whose pixel values match at each movement destination position, that is, the degree of matching is calculated.

As a result of the above, among various positions in the binary image in which the center point of each pixel value matrix 100 lies, the number of pixels with identical pixel values, that is, the position with the largest matching degree is most likely to correspond to the actual position 841 of the first singularity. It is determined to be a high position, and the XY coordinates of that position are detected as the actual position 841 of the first singularity. For example, as illustrated in FIG. 7B, when the pixel value matrix 100 shown in FIG. 7A is overlaid on the region 112 indicated by the dashed-dotted line in the binary image 110, the degree of matching is maximized. Therefore, the position 841 in the binary image 110 corresponding to the center point of the pixel value matrix 100 at this time (ie, the corner point 106 of the product area 102 shown in FIG. 7A) is the first It is detected as the actual location of the singularity. The same pattern matching is also performed for the second singularity of each product 34, and the actual position 842 of the second singularity shown in FIG. 6 is also detected.

Also, as a method of calculating the degree of matching, instead of simply counting the number of pixels with identical pixel values, a method close to the center point of the pixel value matrix 100 (i.e., the corner point 106 corresponding to the singular point 841) is used. A method of assigning a large weighting coefficient to a pixel and assigning a small weighting coefficient to a pixel far from the center point and integrating the weighting coefficients of pixels whose pixel values match can be employed to obtain a degree of match. By this method, the risk of erroneous detection of a singularity on the scrap 82 is further reduced.

Referring again to Fig. 5, in step 63, the XY coordinates of the actual positions 841 and 842 of the two singular points of each product 34 are detected by the image analysis as described above. They are XY coordinates (hereinafter referred to as image coordinates) according to a coordinate system in the image of each imaging area. Next, the image analyzer 324 uses the image coordinates of the actual positions 841 and 842 of the two singular points obtained in the image analysis to control the position of the plasma torch 28 used by the numerical controller 320, respectively. Convert to XY coordinates according to the machine coordinate system (hereinafter referred to as machine coordinates).

Then, the image analyzer 324 notifies the numerical controller 320 of the machine coordinates of the actual positions 841 and 842 of the two singular points.

Then, in step 64 shown in FIG. 5, the numerical controller 320, based on the machine coordinates of the actual positions 841 and 842 of the two singular points of each product 34 notified from the image analyzer 324, A set of values representing the positional displacement amount of each product 34 (set of parallel movement distance value and rotation angle value) is calculated. Then, the numerical controller 320 determines whether or not the positional displacement amount is within a predetermined allowable range based on the set of positional displacement amount values of each product 34 . As a result, if the amount of displacement of each product 34 is within the allowable range, control proceeds to step 66, but if the amount of displacement exceeds the allowable range, control proceeds to step 65. In step 65, the numerical controller 320 outputs, for example, an alarm signal indicating that the amount of displacement of the product 34 exceeds the allowable range to the console 326, and then the product 34 It is excluded from the object of automatic processing by the sub-cutting process after the next step.

On the other hand, as a result of step 64, if the amount of displacement of each product 34 is within the allowable range, control proceeds to step 66, where the numerical controller 320 adjusts the amount of displacement of each product 34 to suit the amount of displacement. The NC program 322 (in particular, product figure data defining the position and shape of each product 34) is corrected. Referring again to Fig. 6, in this control, the machine coordinates (X10, Y10), (X20, Y20) of the singular point normal position (861, 862) of each product 34 obtained based on the original NC program 322 are ) is shifted to the machine coordinates (X11, Y11), (X21, Y21) of the actual position (841, 842) of the detected singularity, translation of translation and rotation is performed with respect to the original NC program 322. That is, the machine coordinates (X10, Y10) and (X20, Y20) of the singular point normal position (861, 862) of each product 34 are expressed as the actual location (841, 842) of the detected singular point of each product 34. The translation distance and rotation angle for moving to machine coordinates (X11, Y11) and (X21, Y21) are calculated, and the coordinates of the translation distance min coordinates of the parallel translation correction and rotation angle min. Rotation correction is applied to the product figure data of each product 34 of the original NC program 322, and a corrected NC program 323 is obtained.

As shown in FIG. 3 , the modified NC program 323 is stored by the numerical controller 320 .

Referring back to FIG. 5 , the numerical controller 320, using the modified NC program 323 in step 68, for each product 34 requiring improvement machining, performs the secondary cutting step of the second step, that is, An additional cut is made to the outer periphery of each product 34 at a second bevel angle (for example, an inclined angle or a normal angle with respect to the main surface of the product 34), and the cross-sectional shape of the cut surface is corrected. It is set to a groove shape designated by the NC program 323 (e.g., a cross-sectional shape such as the Y groove illustrated in FIG. 4B or the X groove illustrated in FIG. 4C). In the modified NC program 323, since the product figure data of each product 34 indicates the actual position of each product 34, the cutting trajectory of the cutting sub-process in the second step is is controlled to an appropriate position according to the actual position of the , and therefore, high-precision processing can be performed.

After that, the numerical controller 320 determines, in step 70, whether all the sub-cutting processes to be performed for each product 34 have been completed, and as a result, the improvement requiring the sub-cutting process of the next step is completed. When processing remains, control of steps 62 to 68 described above for the improvement processing is repeated, and the cutting sub-process of the next step is executed.

After that, the main controller 32 repeats the control of steps 60 to 70 described above with respect to all products 34 defined by the NC program 322 by the control of step 72 .

By the above-described control, the product 34 is cut out from the base material 14 on one plasma cutting device 10, and thereafter, the cut surface of the cut product is subjected to additional cutting processing, a plurality of steps for improvement processing. The sub-cutting process can be executed automatically, continuously and efficiently. In addition, in the control described above, when "cutting" a product in the first sub-cutting process, not only the case where the outer circumference of the product is completely cut along the entire circumference to completely separate the product from the base material (scrap), but only a part of the outer circumference of the product In addition, it can be applied even when a part of it connects the product and the base material (scrap) like a micro joint, thereby improving the processing accuracy of the second and subsequent cutting sub-processes.

By the way, in the above-described control, the positional relationship between the plasma torch 28 (the cutting position by the plasma torch 28) and the image sensor 30 is accurately determined by the numerical controller 320 and the image analyzer 322. should be figured out However, since the position control axis of the plasma torch 28 includes not only the X, Y, and Z axes, but also the B axis and C axis for tilt, when the plasma torch 28 touches or touches another object, either axis There is a possibility that the origin point is slightly displaced from the correct position. Alternatively, there may be cases where the position of the image sensor 30 is shifted for some reason. So, in this embodiment, the main controller 32 detects the positional relationship between the plasma torch 28 (the cutting position by the plasma torch 28) and the image sensor 30, and according to the detected positional relationship It further has a function of calibrating the NC program 322 or other process control data. This calibration can be used at any time, such as when the plasma torch 28 comes into contact with another object, before start of refining process, when power is turned on to the plasma cutting device, or after an earthquake occurs.

Fig. 8 is a diagram explaining the operation of this calibration. 9 is a flowchart showing the flow of this calibration control.

As shown in FIG. 9 , in this calibration control, in step 130, the numerical controller 320 sets the B-axis and C-axis positions of the tilter 26 to the origin of the BC coordinates, and then moves the plasma torch 28 It is driven, and a certain test material placed on the stage along the test cutting line specified by the NC program 322 (this may be the base material 14 for cutting the product 34 or another plate material) (121 ) and conduct a test cut that cuts the

Here, the test cut line may be the L-shaped broken line 120 illustrated in FIG. 8, or a line of any other shape (for example, even if it is just a simple round hole), but in any case , The test cutting line passes through a predetermined XY coordinate position (eg, the origin of the XY coordinates), and where on the test cutting line corresponds to the predetermined coordinate position is an image captured by the image sensor 30 It has a shape recognizable from In the example shown in FIG. 8 , the corner point 122 of the L-shaped test cutting line 120 corresponds to the predetermined coordinate position. Therefore, a point corresponding to the predetermined coordinate position of the L-shaped test cutting line 120, that is, a corner point 122, can be found by the same method as the above-described singularity search method.

Referring back to FIG. 9 , when the test cutting in step 130 is finished, in step 132, the numerical controller 320 sets the offset distance (the distance in the X direction and the distance in the Y direction) set in the numerical controller 320 in advance as described above. The tool moving mechanisms 16 to 26 are moved so that a position corresponding to the cutting position of the plasma torch 28 set at the origin of the BC coordinates comes to a position displaced from the predetermined coordinate position, thereby moving the plasma torch 28 and the image sensor 30 move together. Here, the offset distance is data representing the distance between the center of the imaging area of the image sensor 30 and the cutting position of the plasma torch 28 set at the origin of BC coordinates. After the movement is finished, in step 134, the image analyzer 324 drives the image sensor 30 to obtain an image of the imaging area from the image sensor 30. At this time, if all origin points of the X, Y, Z, B, and C axes of the torch moving mechanisms 16 to 26 are accurate, in the output image 124, the corner point of the test cutting line 120 (above) A point corresponding to a predetermined coordinate position) 122 will be located at the center of the image (center of the imaging area of the image sensor 30) 126. On the other hand, if not, since the actual offset distance is different from the offset distance stored in the numerical controller 320, as illustrated in FIG. 8, within the captured image 124, the corner of the test cutting line 120 A point (a point corresponding to the predetermined coordinate position) 122 deviates from the center 126 of the image 124.

Then, the image analyzer 324 analyzes the image 124 in step 136 of FIG. 120) in the machine coordinate system between the corner points (points corresponding to the predetermined coordinates) 122 (that is, the difference between the actual offset distance and the offset distance stored in the numerical controller 320, (consisting of the amount of positional displacement in the X direction and the amount of positional displacement in the Y direction) is calculated, and the amount of positional displacement is notified to the NC controller 320 . Then, in step 138, the NC controller 320 determines which one of the NC program 322 (specifically, the XY coordinate values of the product figure data of each product 34) and the above-described offset distance by the amount of the positional deviation amount. edit one side Thereafter, after cutting a position corresponding to a certain XY coordinate designated by the NC program 322 with the plasma torch 28, and moving the camera 30 by an offset distance, the cutting corresponding to the XY coordinate position The center of the imaging area of the image sensor 30 is precisely matched to the location. Incidentally, since the center of the imaging area of the image sensor 30 is least affected by the aberration of the lens system of the image sensor 30, by calibrating the center of the imaging area to match the cutting position, the steps in FIG. It becomes possible to perform the control shown in 62 to 68 with high precision.

Next, a plasma cutting device according to a second embodiment of the present invention will be described. In the second embodiment, four improvements are added to the configuration of the first embodiment described above, three of which are for improving the singular point detection performance, and the other one is for improving the singular point detection performance. It is to improve the performance of detecting the position and posture of the base material 14 of the. The first improvement for improving the detection performance of the singularity relates to the arrangement of the image sensor 30 and the illumination of its imaging area, the second improvement relates to a combination of automatic and manual detection of the singularity, and the third improvement, It relates to limiting the image area to be a target of image analysis to a small size. Each improvement is described below.

10 shows a method of arranging the image sensor 30 and a method of illuminating an imaging area of the image sensor 30 in the second embodiment.

As shown in FIG. 10, the image sensor 30 is connected to an elevator 24 (bracket 40) that holds the plasma torch 28 to move in the X, Y and Z directions with the plasma torch 28. is mounted on When the base material 14 is cut by the plasma torch 28, the image sensor 30 is sufficiently higher than the plasma torch 28 so that droplets of molten metal protruding from the base material 14 do not touch the image sensor 30. placed in position. Further, on the bracket 40, two lamps 202 and 204 are mounted at positions near the image sensor 30 on both sides. The two lamps 202 and 204 illuminate the imaging area 210 of the image sensor 30 on both sides of the imaging area 210 on the surface of the base material 14 .

In the image of the imaging area 210 obtained from the image sensor 30, as a factor that makes it difficult to detect a singular point, the surface of the base material 14 is dirty (for example, sputtering), the surface state of the base material 14 ( color, rust, scratches), and poor lighting condition of the environment in which this plasma cutting device is installed (lack of brightness, existence of shadows), and the like. By illuminating the imaging area 210 from both sides with the two lamps 202 and 204, the influence of these factors is reduced, and in the captured image, the gap between the surface of the base material 14 or product 34 and the cut groove is reduced. The difference in brightness becomes clearer. Thereby, the accuracy of automatically detecting a singular point by analyzing an image is improved.

An image of the imaging area 210 output from the image sensor 30 is analyzed by an image analyzer 324 (see FIG. 3). The image analyzer 324 does not analyze the entire image of the imaging area 210, but extracts only an image of a narrow area 216 (hereinafter referred to as an analysis area) close to the center of the image of the imaging area 210, , the image of the analysis area 216 is analyzed. When the pixel pitch of the image output from the image sensor 30 is, for example, about 0.1 mm (that is, the resolution is about 250 ppi), the size of the analysis region 216 is, for example, about 2 inches x 2 inches, and The pixel size of the image in area 216 is about 200 pixels by 200 pixels. If the size of the analysis area 216 and the pixel size of the image are these, the time required for image analysis can be made very short.

It is impossible to always expect 100% reliability for a method for automatically detecting a singularity by image analysis.

If an erroneous detection occurs and the next stage of cutting is performed based on the erroneous detection result, the cut product 34 becomes unusable, so the spent cost, time and labor are useless. Therefore, it is desired to reliably eliminate erroneous detection of the singularity. Therefore, in the second embodiment, when there is a risk of error in automatic detection, there is a function of switching the detection mode from immediate automatic detection to manual detection (specification of a singular point by the operator) without insisting on automatic detection. is mounted As a modified example, if there is a possibility of false detection in the automatic detection result, retry of automatic detection is performed once or twice, and if the possibility of false detection does not disappear even after retrying, the manual detection mode may be switched. do.

11A and 11B show an example of a console 326 for explaining the function of switching the detection method of an outlier from automatic detection to manual detection.

11A and 11B, the console 326 is provided with a display screen 402, an automatic/manual switching button 404, a movement button 406, an alarm sounder 408, and a call lamp 410. has been When the image analyzer 324 automatically detects a singularity by image analysis (in the automatic detection mode), it displays an image in the analysis range 216 on the display screen 402 as illustrated in FIG. 11A, At the center 412 of the display screen 402, the normal position of the singularity specified by the NC program is placed. On the display screen 402, a cursor 414 for indicating a singular point is displayed. When the image analyzer 324 detects the position of the singular point through image analysis, it is determined whether or not the detection is possibly erroneous. For example, if the distance between the position of the detected singularity and the normal position is greater than a predetermined threshold value (eg, a value about the maximum width of a preset cutting groove), there is little possibility that the position of the singularity will be so greatly displaced. , the detection is judged to be possibly erroneous. When it is determined that there is a possibility of false detection in this way, the image analyzer 324 drives the alarm sounder 408 and the call lamp 410 of the console 326 to call a worker, and when an instruction is input from the worker wait without proceeding with control until

Then, when the operator presses the automatic/manual switching button 404 of the console 326, the image analyzer 324 switches from the automatic detection mode to the manual detection mode, and as shown in FIG. 11B, the display screen 402 ) is enlarged so that the area near the normal position of the singularity is displayed in more detail. The operator can move the cursor 414 by manipulating the move button 406 and designate the position of the singular point on the display screen 402 with the cursor 414 . Alternatively, if a touch sensor panel is provided on the display screen 402, the operator may directly designate the position of a singular point on the display screen 402 with the tip of a finger or a pen. Alternatively, it is also possible to move the cursor 414 with a mouse (not shown). In any case, if the position of the singular point on the display screen 402 is designated by the operator, the image analyzer 324 calculates the machine coordinates using the position specified by the operator as the position of the singular point, not the automatically detected position, and The controller 320 is notified.

Fig. 12 shows the flow of the singular point detection process performed by the image analyzer 324, and this flow also includes control over switching from the above-described automatic detection mode to the manual detection mode. This flow corresponds to step 63 in the control flow of improvement processing shown in FIG. 5 .

As shown in Fig. 12, in step 502, the image analyzer 324 analyzes the binary image in the analysis range to detect the position of the singular point. In step 504, the image analyzer 324 checks whether the position of the detected singular point satisfies a predetermined false detection condition. The predetermined false detection condition is, for example, a condition that the distance between the position of the singular point detected as described above and the regular position is greater than a predetermined threshold value (eg, a value about the maximum width of the cutting groove set in advance). to be. In addition to these conditions, other conditions may exist. If the result of this check is no, the position of the detected singularity is determined to be correct (step 506), but if yes, the position of the detected singularity is judged to be possibly incorrect, and control returns to step 508. It goes on.

In step 508, the image analyzer 324 calls the operator and waits until an instruction is input from the operator.

In step 510, when an instruction to switch to manual detection is input from the operator, the image analyzer 324 enlarges and displays an image in the vicinity of the normal position of the singularity on the display screen 402. Then, in step 512, when the operator designates one position on the display screen 402, the image analyzer 324 sets the designated position as the correct position of the singularity.

In this way, by using the automatic detection and manual detection in combination, the location of the singularity can be found reliably. In the case of manual detection, manual detection of the singularity is easy by using a method in which the operator designates the position of the singularity on the image displayed on the display screen 402.

By the way, the above method of displaying a photographed image on the display screen 402 and specifying a desired position by the operator on the image not only detects a singular point, but also ) is also utilized to detect the position (for example, the XY coordinates of the origin) and posture (for example, the inclination angle of one side of the base material 14 with respect to the X axis or Y axis).

Fig. 13 shows the flow of control for detecting the position and attitude of the base material 14 using the image captured by the image sensor 30 in this second embodiment.

When the control shown in FIG. 13 starts, in step 602, the image analysis unit 324 drives the image sensor 30, inputs an image within the imaging range of the image sensor 30, and sends the input image to the console 326. ) is displayed on the display screen 402. The operator manipulates the cursor/camera switch button 416 of the console 326 illustrated in FIG. 11A or 11B to move an object that can be moved by the move button 406 from the cursor 414 to the camera, that is, the image sensor. Convert to (30). Then, in step 604, when the operator inputs a movement instruction by manipulating the movement button 406 of the console 326, the numerical controller 320 moves the image sensor 30 in the X direction and/or in accordance with the movement instruction. or in the Y direction.

While this control is being performed, the image analysis unit 324 continuously inputs an image in the imaging range from the image sensor 30 and displays it on the display screen 402 repeatedly at a high speed cycle, thereby, displaying On the screen 402, an image (moving image) of the imaging range corresponding to the current position of the image sensor 30 is displayed in real time.

The operator can easily send the image sensor 30 to a desired position (even if the position is far from the operator) by operating the move button 406 while viewing an image on the display screen 402 . When one reference point (typically, one corner point) of the base material 14 is displayed on the display screen 402, the operator operates the move button 406 to input a stop instruction. In response to the stop instruction, the numerical controller 320 stops the movement of the image sensor 30.

When the movement of the image sensor 30 is stopped, in step 606, the operator manipulates the cursor/camera switching button 416 of the console 326 to move an object that can be moved by the movement button 406 to the image sensor. Switch from (30) to the cursor 414, and then operate the cursor 414 using the shift button 406 to locate the reference point (corner point) of the base material 14 displayed on the display screen 402. instruct Alternatively, the cursor 414 may be operated with a mouse (not shown), or, if the display screen 402 includes a touch sensor panel, the position of the reference point on the display screen 402 is the operator's fingertip or It may be directed directly with the tip of a pen or the like. By this method of specifying a reference point on an image displayed on the display screen 402, the operator can easily designate a reference point even when the reference point is far from the operator or when the environmental lighting is dark. When a position on the base material 14 displayed on the display screen 402 is indicated by the operator in this way, the image analyzer 324 determines the image coordinates of the indicated position as the image coordinates of one reference point of the base material 14. do. Then, in step 608, the image analyzer 324 converts the determined image coordinates of one reference point into machine coordinates, and transmits the machine coordinates to the numerical controller 320.

The processing of steps 604 to 610 described above is repeated for all reference points to be determined (for example, three corner points of the base material 14). As a result, the numerical controller 320 acquires the machine coordinates of all reference points of the base material 14 .

After that, the numerical controller 320 determines the position (eg, XY coordinates of the origin of the base material 14) and posture (eg, the base material 14) of the base material 14 based on the machine coordinates of all reference points of the base material 14. , the inclination angle with respect to the X axis or Y axis of one side passing through the origin of the base material 14) is calculated. The position and posture of the base material 14 determined in this way are used by the numerical controller 320 in the subsequent cutting process (see Fig. 5), whereby the numerical controller 320 determines that the base material 14 is machine No matter what positional relationship is placed with respect to the coordinate system, when cutting each product from the base material 14 according to the NC program, the position at which the base material 14 is cut is controlled to a position specified by the NC program.

As described above, a method in which an operator designates a point in an image displayed on a screen to teach a numerical controller the reference point of a base material is not only an automatic cutting machine having a function of performing improvement processing, but also a function of performing improvement processing. It is also applicable to automatic cutting machines that do not have it, and is also useful. Some types of large plasma cutting machines do not have tools or stoppers for positioning the base material on the table. In such a machine, special work is required to teach the numerical controller the positional relationship between the machine coordinate system and the base material. Conventionally, a method in which an operator slowly moves a laser pointer whose positional relationship with a cutting tool is previously grasped by a numerical controller to a corner point of the base material by a manual jog mechanism, and teaches the coordinates of the corner point to the numerical controller are employed Alternatively, the image from the CCD camera photographing the base material is displayed on the screen, and the operator moves the CCCD camera with a manual jog mechanism until the corner point of the base material in the displayed image reaches the marker point position in the center of the screen. How to do it is also adopted. However, in any conventional method, laborious and time-consuming work is required for the operator to move the laser pointer or CCD camera slowly and carefully by the jog mechanism.

In contrast, according to the method shown in FIG. 13, since the base material's reference point (eg, corner point) simply needs to enter the imaging area of the image sensor (eg, CDD camera), the image sensor can be moved at a higher speed and more roughly. can be made, and the operation to be performed by the operator is simpler.

And, the method of teaching the numerical controller the reference point of the base material by designating a point in the displayed image by the operator as described above can be used not only for the purpose of informing the controller of the position and attitude of the base material, but also for other purposes. For example, in the case of performing manual cutting in which the base material is cut along a point or line on the base material specified by the operator, instead of cutting automatically by executing the NC program, each point or angle to be cut is performed. It can also be applied for the purpose of telling the controller the coordinates of the line (each of the points defining each line). In this case, for example, when a worker operates a jog mechanism to move the imaging area of the image sensor on the base material and designates one or more arbitrary points in the image of the displayed imaging area, the controller determines the coordinates of each designated point. is grasped as the coordinates of each reference point (each point defining each point to be cut or each line to be cut), and then, the cutting operation can be performed by moving the cutting tool according to the coordinates of each identified reference point. .

As mentioned above, although embodiment of this invention was described, this embodiment is only an example for description of this invention, and the scope of this invention is not limited to this embodiment only. This invention can be implemented also in other various aspects, without deviating from the summary.

Claims (9)

A method for continuously and efficiently processing a multi-step sub-cutting process of improvement processing using an image sensor, comprising: a stage (12) for placing a base material (14), a cutting tool (28), and an image sensor having an imaging area 30 and a tool for moving the cutting tool 28 relative to the stage 12, changing the angle of the cutting tool 28, and also moving the imaging area of the image sensor 30 moving mechanisms 16 to 26 and a controller 32 for controlling operations of the cutting tool, the image sensor, and the tool moving mechanism, respectively, according to an NC program 322;
The controller 32 performs control to execute a first sub-cutting step of cutting the product 34 by cutting the base material 14 placed on the stage 12 with the cutting tool according to the NC program. regular positions (861, 862), set an imaging area of the image sensor 30 in one or more areas 881, 882, and control to acquire images of the one or more areas 881, 882 from the image sensor. The actual positions of the two or more singular points of the cut product 34 on the stage (841 , 842), and according to the detected actual positions (841, 842) of the singularity, the NC program 322 to adapt to the actual position of the cut product 34 on the stage. Program correcting means 66 for correcting, and controlling to execute a second sub-cutting process for performing additional cutting by the cutting tool on the cut product 34 on the stage according to the corrected NC program 323; A method for continuously and efficiently processing a plurality of sub-cutting steps of improvement processing using an image sensor, characterized in that it has a second sub-cutting process control unit (70) for controlling the sub-cutting process. The method according to claim 1, characterized in that two or more corner points of the outline of the product (34) are selected as the two or more singular points. How to. The method according to claim 2, wherein the singular point detection means (63) detects a plurality of line segments constituting an outline of the cut product (34) in the image of the one or more areas (881, 882), Detecting two or more corner points formed by crossing a plurality of line segments, as the actual positions (841, 842) of the two or more singular points How to process continuously and efficiently. The method according to claim 1, wherein the singular point detection means (63) expresses a shape in the vicinity of each of the regular positions (861, 862) of the two or more singular points of the product figure defined by the NC program. A pixel value matrix of is applied to various positions in the image of the one or more regions 881 and 882 to calculate a degree of pattern matching with the pixel value matrix at various positions in the image, and the calculated pattern matching degree Continuously and efficiently processing a plurality of steps of sub-cutting process of improvement processing using an image sensor, characterized in that one position where is maximal is detected as each of the actual positions (841, 842) of the two or more singular points. How to. 2. The program according to claim 1, wherein the program correcting means (66), based on a positional relationship between the detected actual position (841, 842) of the singularity and the normal position (861, 862) of the singularity, converts the NC program. A method for continuously and efficiently processing a plurality of steps of sub-cutting process of improvement processing using an image sensor, characterized in that by correcting. The method according to claim 1, wherein the range in which the singular point detecting means (63) detects the actual positions (841, 842) of the two or more singular points in the image of the one or more regions (881, 882) is set to the range of the two or more regions. A method for continuously and efficiently processing multiple steps of sub-cutting process of improvement processing using an image sensor, characterized in that it is limited to only the range (901, 902) in the vicinity of the normal position (861, 862) of the singularity. The cut product (34) according to claim 1, wherein the controller (32), based on a positional relationship between the detected actual position (841, 842) of the singularity and the normal position (861, 862) of the singularity, means (64) for judging whether or not the positional displacement amount is excessive, and means (65) for stopping the execution of the second cutting process for the cut product (34) when it is determined that the positional displacement amount is excessive. A method for continuously and efficiently processing a plurality of sub-step cutting processes of improvement processing using an image sensor, further comprising: The method according to claim 1, characterized in that the imaging areas of the cutting tool (28) and the image sensor (30) maintain a constant positional relationship and are moved together by the tool moving mechanism (16 to 26). A method of continuously and efficiently processing a multi-step sub-cutting process of improvement processing using an image sensor. The test material according to claim 1, wherein the controller (32) uses the cutting tool (28) to set the test material on the stage (12) along a test cutting line passing through predetermined coordinate points designated by the NC program. means 130 for performing control to execute a test cut to cut 121, and after the test cut is executed, a position between the cutting position of the cutting tool 28 and the imaging area of the image sensor 30 Based on the predetermined offset data representing the relationship, the imaging area of the image sensor 30 is moved to an area including the predetermined coordinate point, and the image sensor 30 includes the predetermined coordinate point. means (132-134) for performing control to acquire an image of an area, and an image of the area including the predetermined coordinate points acquired from the image sensor (30) is analyzed, and the cutting tool (28) and the image means 136 for detecting an actual positional relationship between imaging areas of the sensor 30 and means 138 for correcting the NC program or the offset data, based on the detected actual positional relationship A method for continuously and efficiently processing a plurality of steps of sub-cutting process of improvement processing using an image sensor, characterized in that it has.

Images