JPH077292B2 - Two-dimensional tool trajectory generation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a two-dimensional tool trajectory generation method for generating a two-dimensional trajectory when a tool is moved to machine a machining area with a numerically controlled machine tool.

[Prior Art] In recent years, FA (Factory Automation) and FMS (Flexible Manu
facturing system) has been widely proposed, and such a system uses a numerically controlled machine tool to automatically perform cutting, welding, fusing, and drawing work.

This numerically controlled machine tool moves the selected tool based on the numerical data (that is, the control program) such as the moving position and speed that are given in advance, and processes the target workpiece (workpiece). To do.

Conventionally, in order to input a control program to such a numerically controlled machine tool, the shape of the workpiece is defined by a predetermined programming language for numerical control, or if the machining shape is complicated, a model of the machined shape is used. (Master) is formed, the surface of this master is traced by a tool, and the trace position is directly input to the numerically controlled machine tool (copying).

However, with the former method, it is difficult to input a complicated shape and it is difficult to create a program because it is necessary to acquire a programming language for numerical control. In addition, the latter method is not preferable because it takes time, time and cost for creating the master.

In addition, when generating the trajectory of the tool for machining the input machining shape, an offset path is formed by offsetting the contour line of this machining shape inward by an amount corresponding to the tool radius, and repeating this in sequence. Although the tool path is formed, in such a method, depending on the machining shape, uncut parts are left in the central part and the like, and complicated processing is required to process the uncut parts.

Furthermore, if there is a portion (so-called island) to be left without being machined in the machined shape, more complicated processing is required, and it is extremely difficult to automatically generate a tool path for properly machining the machined shape. It was very difficult.

[Purpose] The present invention has been made in view of the above-mentioned circumstances,
It is an object of the present invention to provide a two-dimensional tool trajectory generation method capable of automatically generating a tool trajectory.

[Structure] The present invention is a tool for inputting an image of a processing area, extracting a contour line of the processing area that appears in the image data, and working from the contour line toward the inside of the processing area with a plurality of tools having different diameters. Separate machining areas are formed in order from a tool corresponding to a tool having a small diameter, and a one-stroke written two-dimensional tool locus corresponding to each tool is formed based on the offset amount and the overlap amount of each tool, It automatically generates a tool path with no uncut residue.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an apparatus according to an embodiment of the present invention.

In the figure, the data processing unit 1 executes a process described later to generate a tool trajectory.
A keyboard 2 for inputting operator's operation information, an image reading unit 3 for inputting a processed shape, and a memory 4 for storing a read image, an intermediate file, and the like are connected.

The screen display unit 5 is composed of, for example, a bitmap display device, and is used to display various messages from the data processing unit 1 to the operator, read images, and the like, and the display control unit 6 controls the screen display unit 5. It is for controlling display contents.

Therefore, the operator can interactively proceed with the operation and work, and can visually confirm the processing status. Further, the keyboard 2 is provided with a pointing device capable of indicating an arbitrary position of the screen display unit 5 in display pixel units, and the image reading unit 3 uses an image scanner or the like used in an image input unit of a facsimile apparatus. You can Therefore, the image read by the image reading unit 3 is
It is divided into pixels with a predetermined resolution in the main scanning direction and the sub-scanning direction, and each pixel has black and white binary information corresponding to each density.

By the way, the data processing unit 1 executes the two-dimensional tool locus generation processing shown in FIGS. 2A and 2B to obtain a contour machining tool suitable for machining a small diameter small portion and a large diameter machining tool. A two-dimensional trajectory of a saray processing tool suitable for processing a wide area is generated. In this case, the processed area is represented by a black image.

First, the processing area represented by a black image in the read image data is divided into a saray processing area to be processed with a saray processing tool and a contour processing area to be processed with a contour processing tool (process 110). In this processing 110, the contour line of the machining area is extracted, and the distance of the larger dimension of the contour line is twice the diameter of the contour machining tool or the value of the radius of the saray machining tool plus the diameter of the contour machining tool. The area inside only is identified as the contour processing area, and the other portion is identified as the saray processing area.

That is, as shown in FIG. 3, first, the contour line of the processing area is extracted (process 201). In this process 201, an image is scanned in a fixed direction from a reference position, and a pixel that first changes from white to black is determined as a start pixel, and that pixel is used as a starting point, and then white to black (or black to white). ), The adjacent pixel (change pixel) that has changed to (1) is found, and its direction is represented by one of the vectors in the eight directions shown in FIG. 4 (a). Find the next change pixel counterclockwise from the direction of the vector two to the left of the vector that entered the change pixel as the starting point, represent by one of the eight direction vectors, and return to the start point Repeatedly until it comes (8 connected belt tracking; see FIG. 4 (b)).

Then, the closed curve forming the contour line is represented by the position coordinates of the starting point and the data consisting of a sequence of vectors of changing pixels successively consecutive thereto. A mark indicating the end is added to the end of the contour line data.

However, an angle where the difference between the two vectors is 180 degrees or more cannot form a contour line, and therefore a changing pixel is searched for in the counterclockwise direction (see FIG. 4 (c)). The angle formed by these two vectors can be calculated by calculating the inner product of the two vectors as shown in the following equation (I).

θ = cos ⁻¹ (V ₁ · V ₂ / (| V ₁ | · | V ₂ |)) ・ ・ ・ (I) Here, V ₁ is a plural number (eg 5 ) Represents the average vector of the vectors, and V ₂ represents the average vector of a plurality of vectors in the direction of going out from the changed pixel.

When the contour line is extracted in this way, when it is the first time (the result of the judgment 202 is YES), the contour line extracted at that time represents the outermost contour of the machining area, and therefore the data of this outermost frame (start point The position coordinates and vector data of are stored (step 203).

Then, for the pixels extracted as contour lines in process 201,
Add a processed mark that indicates processed (Process 20
Four). However, in order not to divide the processing area as much as possible,
As shown in FIG. 4 (d), the processed mark is not added to a portion where the contour lines are not separated by two or more bets. The distinction between the pixel to which this processed mark is added and the pixel to which it is not added is
It can be discriminated by the relationship between the vector entering the pixel and the vector from that pixel to the pixel going out to the next change pixel. In the figure, the processed mark is indicated by Δ.

Next, it is checked whether or not the contour line is curved out from the outermost frame by a predetermined number of pixels (decision 205).
If NO, the process returns to step 201. At this time, the contour line that forms the boundary between the pixel to which the processed mark is added and the processing region is extracted, and the pixels forming the contour line inside the processing region are sequentially extracted. , A processed mark is added to the extracted pixel.

Here, the number of pixels determined in the determination 205 is the number of pixels corresponding to the contour processing area, that is, twice the diameter of the contour processing tool or the larger value of the radius of the saray processing tool plus the diameter of the contour processing tool. It is the corresponding number of pixels. Therefore,
At the time when this determination 205 is completed, the processed mark is added to the pixels inside the contour processing area within the contour line of the outermost frame.

By the way, according to the processing 204, since the processing areas are made continuous as much as possible, the processed mark is not added to the portion where the intervals of the contour lines are not separated by 2 bits or more, and the main scanning direction or the sub-direction of the image is not added. In the part inclined at 45 degrees to the scanning direction, the range of the area actually processed by the contour processing tool The processed mark is added only up to.

Therefore, in order to accurately form the area actually processed by the contour processing tool, the vector data representing the contour line of the outermost frame stored in step 203 is read (step 206), and the number of pixels of the contour processing area is set to 2 When the center of a processed circle drawn with a doubled diameter is moved along the contour line of this outermost frame, the pixels that belong to the area inside the processed circle and have no processed mark have been processed. A mark is added to correct the processing area (process 207).

As a result, the processed mark is added to the pixels in the portion corresponding to the accurate contour processing area.

In this way, when the processing area is divided into the contour processing area and the saray processing area, the pixels of the processing area to which the processed mark is not added are marked with the saray processing area to form the data of the saray processing area. Then, this is stored (process 120).

Next, the mark-added portion of the saray-processed area is converted into data of the non-working area, that is, white pixels, and the pixel to which the processed mark is added in the processing 110 is returned to the black pixel state (processing
130).

Therefore, for example, when an image as shown in FIG. 5 is input from the image reading unit 3, the portion BL drawn in black in this image is displayed.
Is discriminated as a machining area, and as shown in FIG. 6A, the contour machining area RA is machined by the contour machining tool and the saray machining area RB is machined by the saray machining tool.

In this way, when the contour processing area and the saray processing area are calculated, next, the contour processing trajectory for processing the contour processing area with the contour processing tool and the saray processing trajectory for processing the saray processing area with the saray processing tool The processing 140,150
To form each.

In the contour processing locus calculation processing 140, first, in the state where the contour processing area is formed in the processing 103, the processing of FIG. 3 is applied to the number of pixels corresponding to the radius of the contour processing tool, and The outermost frame of the contour processing area is cut by the radius of the contour processing tool to update the processing area (process 141). At this time, a processed mark is added to the pixel of the part that is cut off.

Next, in the updated processing area, the boundary line (contour line) between the pixel to which the processed mark is added and the black pixel is processed as shown in FIG.
It is calculated by the same method as 201, and the calculation result (that is, the tracking vector) is smoothed, and the circle and tool diameter 10
The outermost frame tool locus of the contour processing tool represented by a combination of a straight line that is more than twice as long, a vertex, a short straight line, a circular arc, and a free curve is calculated (process 142).

That is, as shown in FIG. 7, first, the circle portion of the contour line is determined (process 301). In this process 301, each coordinate of the contour line is substituted into the following formula (II) to calculate the value of C at each coordinate, and when C is constant, it is determined to be a tentative circle. When it is determined that the circle is a provisional circle, a plurality of arbitrary three points on the contour line are appropriately selected and the center of the circle passing through the three points of each set is calculated, and the average position of the plurality of centers is calculated. Then, the provisional center when the contour is regarded as a circle is obtained.

Next, a circle equation such as the following equation (III) is formed from the thus obtained temporary center, and the absolute value of the distance Δli between each pixel data and the temporary circle calculated by the equation (III) is calculated. Whether the tentative circle calculated by formula (III) based on the following formulas (IV) and (V) can be identified as the actual circle by calculating the accumulated value SA and accumulated value SB of the values To judge.

C = (x ² + y ² ) y (II) (x−xc) ² + (y−yc) ² = Γ ² (III) Here, since a circle forms one closed curve, it is checked whether or not all the loci forming one contour line have ended by the judgment of this circle (judgment 302), and if the result of this judgment 302 is NO, the next Proceed to processing.

Next, a straight line having a length ten times or more that of the contour processing tool is calculated (process 303). In this process 303, an average vector of five unit vectors is formed, and a tentative straight line section is calculated from the vector angle of the average vector based on the following equation (III).

Next, the integrated value SA and the integrated value SB of the absolute value of the distance Δli between each pixel data and the tentative straight line calculated by the formula (VI) are calculated based on the formulas (IV) and (V), respectively. Based on the result, it is determined whether the provisional straight line calculated by the formula (VI) can be identified as an actual straight line.

ax + by + c = 0 (VI) Furthermore, a histogram in the direction of the vector is further formed,
If there is only one peak in the histogram, the section is determined as a straight line, and if there are more peaks in the histogram, it is determined as other.

Next, the vertices appearing in the contour line are discriminated for the portions which are not discriminated as circles and long straight lines in the processing 301 and the processing 303 (processing 304).

In this process, the average vector formed in process 303 is substituted into the formula (I) to calculate the angle formed by the two average vectors, and the vertex is discriminated based on the calculation result. At this time, as shown in FIG. 8, the point P1 may be erroneously determined as the apex depending on the starting point of calculation of the average vector. , The average vector calculation starting point is sequentially changed, and the angle formed by the two average vectors is the sharpest,
In addition, the stable state is determined, and the appropriate vertex Pt is detected accordingly.

Next, a section between the end points of the straight line calculated in step 303 and the apex calculated in step 304, or a portion that can be determined to be a straight line in the section between the apexes is calculated using the same judgment criteria as in step 303. Yes (process 305).

Next, an arc portion is calculated for the section not processed by the processes 301, 303, 304, 305 (process 306). This process 306
Then, a tentative arc section is calculated in substantially the same manner as in step 301, the tentative center of this tentative arc section is calculated based on the coordinates of the eight points of the tentative arc section, and the tentative center is used to calculate the formula (III ) Form a circle equation.

Then, the difference between this temporary arc and the actual pixel coordinates is calculated by the above equations (IV) and (V), and it is determined whether the temporary arc section is appropriate based on the calculation result. The radius is determined along with the determination.

Finally, a free curve consisting of a spline curve is fitted to the sections not covered by the processing 301, 303 to 306 (processing 307).

In this way, the outermost frame tool locus of the contour processing tool is calculated by the process 142.

Then, the processing of FIG. 3 is applied to the number of pixels corresponding to the overlap amount of the contouring tool, and when the contouring tool passes through the outermost frame tool trajectory and when the contouring tool has one inner tool trajectory. The processed mark is added to the pixels in the portion corresponding to the overlap amount when the image has passed (process 143).
In this process 143, a process that does not lose continuity is performed so that the tool path becomes a single stroke.

Such processing 141, 142, 143 is repeatedly executed until the outermost frame of all the machining areas is applied (loop of determination 144), and the outermost frame tool locus of the contour machining area of each machining area is calculated.

Next, the processing of FIG. 3 is applied to the number of pixels corresponding to the offset amount of the contour processing tool to extract an offset line for processing the inner processing area (processing 145), and smoothing corresponding to this offset line. An unprocessed tool locus is calculated (process 146), the process of FIG. 3 is applied to the number of pixels corresponding to the overlap amount of the contouring tool, and processed pixels are added to the overlapped pixels (process 14).
7) The processes 145, 146, and 147 are repeatedly executed until the processed marks are added to all the pixels in the contour processing area (determination 1
(Loop of 48), and calculate a tool locus for machining the contour machining area other than the outermost frame.

In this way, the contour machining trajectory calculation processing 140 calculates the tool trajectory of the contour machining tool in all contour machining areas.

Then, next, the tool path for processing the saray processing region with the saray processing tool is calculated by the saray processing trajectory calculation processing 150.

In the saray processing locus calculation processing 150, first, after reading the data of the saray processing area stored in the processing 120 (processing
151), the same processing as that in which the processing 141 is omitted in the contour processing locus calculation processing 140 is executed for the diameter and the overlap amount of the specified saray tool (processing 152, 153, judgment 1).
54, processing 155, 156, 157, decision 158).

Note that it is not necessary to form an offset line for processing the outermost diameter of the saray processing area here because the contour processing area and the saray processing area are divided in step 110 when the contour processing area Since the radius is set larger than the radius, even if the saray tool is moved along the outermost frame of the saray processing area, there is no risk of processing outside the processing area set in the read image.

As a result, the tool trajectory of the saray processing tool in all the saray processing regions is calculated.

As described above, the image of the processing area is formed on the original document, and the original document is read by the image reading unit 3, and the tool locus and the saray processing of the contour processing tool as shown in FIG. The tool path of the tool is automatically formed. In addition, the distortion and the like of the image at the time of reading are removed as a result of being smoothed by the process 142.

In FIG. 6 (b), the broken line indicates the tool locus of the contour processing tool, and the alternate long and short dash line indicates the tool locus of the saray processing tool. However, in this case, the innermost tool locus of the contour machining tool and the outermost tool locus of the saray machining tool overlap.

By the way, in the above-described embodiment, the case where the processing area set in the read image is cut by the two tools of the contour processing tool having a small diameter and the saray processing tool having a large diameter has been described. The present invention can be similarly applied even when three or more tools are used. Further, since the tool loci are generated by the tools having different diameters as described above, the present invention is particularly applicable to a numerically controlled machine tool having a function (auto tool changer) capable of automatically exchanging tools. Very effective.

Further, in the above-described embodiment, the black pixel portion of the read image is determined as the processing area, but the white pixel portion may be determined as the processing area. In that case, the black pixel portion of the image obtained by inverting the read image in black and white may be determined as the processing region.

As a method for smoothing the tool locus, a method other than the above-mentioned embodiments can be used.

Further, in the above-described embodiment, the image reading unit reads the document on which the image of the processing area is formed in advance, and the processing area is identified from the read image. However, the processing area including the line drawing is displayed by the screen display unit and the keyboard. It is also possible to input the processing area by forming the image and designating a black and white image on it.

[Effect] As described above, according to the present invention, an image of a processing area is input, a contour line of the processing area that appears in the image data is extracted, and the contour line is directed to the inside of the processing area.
A machining area for each tool to be machined with multiple tools with different diameters
It forms in order from a tool with a small diameter, and forms a one-stroke written two-dimensional tool locus corresponding to each tool based on the offset amount and overlap amount of each tool, and there is no uncut residue. Since the tool locus is automatically generated, the labor and time for forming the tool locus can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a data processing device according to an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are flowcharts showing a processing example for generating a tool path, and FIG. 4 is a flowchart showing an example of processing for extracting a processing region, FIGS. 4A to 4D are explanatory views for explaining contour line extraction, and FIG. 5 is a plan view showing an example of a read image. 6 (a) and 6 (b) are explanatory views for explaining the intermediate state of the processing, FIG. 7 is a flowchart showing an example of the smoothing processing, and FIG. 8 is an explanatory view for explaining the identification of the vertices. Is. 1 ... Data processing unit, 2 ... Keyboard, 3 ... Image reading unit, 4 ... Memory, 5 ... Screen display unit, 6 ... Display control unit.

Claims (3)

[Claims] 1. An image corresponding to a machining area to be machined by a numerically controlled machine tool is formed, a contour line appearing in the machining area is extracted based on data of the image, and the contour line is directed from the contour line toward the inside of the machining area. The machining area for each tool to be machined with multiple tools with different diameters is formed in order from the tool corresponding to the tool with the smallest diameter, and each of them is based on the offset amount and overlap amount of the tool corresponding to the machining area for each tool. A two-dimensional tool locus generating method, characterized in that a one-stroke-shaped two-dimensional tool locus corresponding to a tool is formed. 2. The two-dimensional tool locus generating method according to claim 1, wherein the contour line is formed by connecting adjacent change pixels with a vector. 3. The two-dimensional tool locus for forming a contour line in the outermost machining region according to claim 1, wherein the portion is a circle, a straight line, a vertex, a circular arc or a free curve. It is formed on the inside by an offset amount in a smoothed state by being converted to any of the above, and in the other machining area for each tool, the outermost two-dimensional tool locus is formed along its contour line. A characteristic two-dimensional tool trajectory generation method.