JPS62221004A - Method for producing locus of 2-dimensional tool - Google Patents

Abstract

PURPOSE:To properly form a working area from a working form drawn by lines by counting the picture elements added with the 1st identification code crossing a scan line when the working form is scanned in a fixed direction to decide the internal picture elements of the working area with an area having the odd even count value of picture elements and then painting out the decided inside area. CONSTITUTION:An input working form is stored in a storage device 4 in the form of data. A data processing part 1 transfers the working form, i.e., the contour curves I-III are transferred to a video RAM 5 and displays them on a screen display part 3. Then an operator supplies the offset value of a contour working tool. The part 1 forms the offset contour curves I'-III' by reducing the curves I-III toward the working area by a ratio equal to the input offset value. The display on the part 3 is changed with those curves I'-III and at the same time the curves I'-III' are stored in the device 4 as the contour working tool lock. Then the part 1 paints out a working area A' enclosed by curves I' and II' as well as a working area B' enclosed by the curve III'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a two-dimensional tool trajectory generation method for generating a two-dimensional trajectory when moving a tool to machine a machining area with a numerically controlled machine tool.

[Prior art] In recent years, FA (Factory Automation)
and FMS (Flexible Manufacturing
g 5yten+) has been widely proposed, and numerically controlled machine tools are used in such systems to automatically perform cutting, welding, fusing, drafting, etc.

This numerically controlled machine tool moves one selected tool based on numerical data (i.e., control program) such as movement position and speed given in advance, and moves the workpiece (
It is used to process objects (workpieces) into desired workpieces.

Conventionally, in order to input a control program into such a numerically controlled machine tool, the shape of the workpiece was defined using a predetermined numerical control programming language, or, if the machining shape was complex, a model of the workpiece shape was used. (mask) is formed, the surface of this mask is traced once with a tool, and the trace position is directly input into a numerically controlled machine tool (copy processing).

However, when filling out and forming the machining area for actual machining from the input machining shape in this way, there may be parts that cannot be filled in depending on the machining shape, so it is necessary to automatically form an appropriate tool path. I couldn't do that.

[Purpose] The present invention has been made in view of the above-mentioned circumstances, and
It is an object of the present invention to provide a two-dimensional tool trajectory generation method that can appropriately form a machining area from a machining shape formed by a line drawing and automatically generate a tool trajectory.

[Structure] The present invention forms an offset line of a machining shape formed by a line drawing, stores this as a locus of a contour machining tool, adds a first identification code to pixels forming the offset line, and adds a first identification code to the offset line. Appearing vertices and individual lines are detected and a second identification code is added to the pixels forming them. Then, when the processed shape is scanned in a certain direction, the pixels to which the first identification code is added that intersect with the scanning line are counted, and areas where the count value is an odd number are determined to be pixels inside the processed area. Areas where the count value is an even number are determined as pixels outside the processing area, and portions determined as inside the processing area are filled in, thereby forming the processing area.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

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

In the figure, a data processing section 1 executes processing to be described later to generate a tool trajectory, and a keyboard 2 has full keys for inputting operation information from an operator to the data processing section 1 and, for example, 400 points in the horizontal direction. An arbitrary position on the screen display section 3 having a resolution of 400 points in the vertical direction can be indicated in display pixel units, and a pointing device is provided for forming a line drawing of the processed shape.

A storage device 4 stores data such as various intermediate files, a video RAM (random access memory) 5 stores data to be displayed on the screen display section 3, and a display control section 6 stores video data. Display data stored in the RAM 5 is displayed on the screen display section 3. The screen display section 3 and display control section 6 constitute a so-called bitmap display device. Further, this bitmap display device and keyboard 2 constitute a graphics terminal.

In such a work environment, operators can perform operations and work interactively and visually check the processing status.

With the above configuration, the operator first instructs the data processing section 1 to form a machining shape from the keyboard 2, and while talking with the data processing section 1 via the keyboard 2 and the screen display section 3, for example, as shown in FIG. A processed shape consisting of a line drawing as shown in (a) is drawn on the screen display section 3. The machining shapes input here are straight lines 1 to LL4 and circular arcs At, A2.
The area A is composed of the axial contour curve I formed by the contour curve I, the contour curve ■ formed by the straight lines L21 to L23, and the contour curve ■ formed by the circle A31, and is surrounded by the contour curve I and the contour curve ■. A region B inside one contour curve ■ is set as a processing region.

A method for forming such a processed shape using a line drawing is, for example, by connecting two points on the screen display section 3 specified with a pointing device with a straight line, or by specifying the center and drawing a circle or arc. Alternatively, there is a method of inputting the machining shape by directly defining it as a numerical value (formula) using a specific programming language.

The machining shape input in this way is stored in the video RAM 5.
Since the data is stored as data in the data processing unit 1,
stores the data finally stored in the video RAM 5 in the storage device 4 as data of the input machining shape.

When the operator finishes inputting the definition of the machining shape, the data processing unit 1 calculates the contour curve 1, If of the machining area.

The processing routine shown in Figure 3 is a contour machining tool trajectory for machining ■ with a contour machining tool with a small diameter, and a contour machining tool trajectory for machining machining areas A and B with a contour machining tool with a large diameter. The contour machining tool trajectory and the contour machining tool trajectory thus generated are stored in the storage device 4.

That is, first, the data processing unit 1 converts the processed shape, that is, the contour curves t, n, m stored in the storage device 4 into the video R.
The data is transferred to the AM 5 and displayed on the screen display unit 3 by the display control unit 6 (process 110), and the operator is prompted to input the offset amount (radius) of the contour processing tool.

Next, the data processing unit 1 processes each contour curve! .

An offset contour curve B, ■l, [11, which is obtained by reducing ■, ■ in the direction of the machining area by the input offset amount, is formed by a well-known appropriate method, and this offset contour curve 1', n', I[I ' to rewrite the display on the screen display section 3, and also change the offset contour curve 11゜n', m
' is stored in the storage device 4 as a contour machining tool trajectory.

Then, the data processing section 1 fills out the processing area A' surrounded by the offset contour curve B and the offset contour curve ■' and the processing area B' surrounded by the offset contour curve ■' (process 13o).

In this filling process 130, the process shown in FIG. 4 is performed so that no areas that cannot be filled out appear.

First, "1" is assigned to the pixels on the offset contour curves Bi, ■l, ■j, and rQJ is assigned to the other pixels (process 201). At this time, for example, the offset contour curve of the machining shape is If it is as shown in a), the pixels that make up the offset contour curve are as shown in figure (b).
The result will be as shown in . In FIG. 3B, black circles indicate pixels forming the offset contour curve, and white circles indicate pixels in other parts.

Next, pixels are scanned in the horizontal direction of the image (corresponding to the horizontal scanning direction of the screen display section 3) from the reference position (for example, the position of the upper left corner of the screen display section 3), and the pixels change from "0" to "1". The first pixel S, that is, the start pixel S of the contour shape (contour curve) is found, and the coordinate values of the start pixel S are stored (process 202).

Next, all the contour lines forming the offset contour curve are extracted by the 8-connected vector tracing method using this start pixel S as the starting point, and the data of the pixels forming these contour lines is replaced with "2". (Process 203).

This 8-connected vector tracking method uses the starting pixel S as the starting point, then finds an adjacent pixel (change pixel) whose value is rlJ, and then calculates the direction of the vector in the eight directions shown in Figure 5(c). Hail by one of them.

Next, starting from the found change pixel, move counterclockwise from the direction of the vector two places to the left (or clockwise from the direction of the vector two places to the right) from the vector that entered the change pixel to the next change pixel. By finding the position of the pixel and determining its position using one of the eight directional vectors, and repeating this sequentially until it returns to the starting point, we can calculate the coordinate value of the starting pixel and the successive change pixels. This is a method of finding a closed curve forming a contour line using data consisting of a sequence of vectors. Note that a mark indicating the end of the outline data is attached at the end of the outline data.

When the offset contour curve is extracted in this way, based on the contour data (that is, the coordinate values of the start pixel S and the data of the tracking vector), the vertices of the offset contour curve and a line with a width of 1 pixel (overlapping lines), and their vertices and the values of pixels detected as overlapping lines are replaced with marks R (processes 205, 206). Here, a vertex is a part where the angle between the vector entering the pixel and the vector exiting the pixel changes sharply, or where the change in direction between the vector entering the pixel and the vector exiting the pixel is convex in the horizontal direction. Refers to the part that is shaped like An overlap line is a portion where the vector entering the pixel and the vector exiting the pixel are in opposite directions.

Note that the angle formed by the vector in the direction of entering the pixel and the vector in the direction of exiting the pixel can be calculated by calculating the inner product of the two vectors as shown in the following equation (1).

θ: cos-1(V, ・V, /(I V, il V21
)) ... (1) Here, ■1 represents a vector in the direction of entering the pixel, and ■, represents a vector in the direction of exiting from the pixel.

Next, scan the image horizontally and find the value of the previous pixel r
The pixels that are QJ and have a value of "2" are counted, and the pixels located in the interval where the count value is an odd number are determined as pixels inside the processing area, and the pixels located in the period where the count value is an even number are determined. The located pixel is determined as a pixel outside the processing area, and the value of the pixel determined as a pixel inside the processing area is replaced with a hail mark I inside the processing area (processing 2
07,208).

That is, special marks R are added to vertices and overlapping lines that are obstacles when identifying the inside of the processing area by scanning in the horizontal direction, and when processes 207 and 208 are executed, those marks R are added. Since the pixels that are present are not counted, the processing area can be filled in accurately.

In this way, the mark ■ is given to the pixel located inside the processing area, and finally the value is "2" or the mark R
, H, all pixel values are replaced with "1",
This completes the filling of the processing area. The state is shown in FIG. 5(d). Further, the data of the processing area thus formed is stored in the storage device 4 as Sarai processing area data.

Next, with respect to the offset machining areas A' and B' that have been filled in and formed in this way, the tool trajectory for machining each of the offset machining areas A' and B'' with a machining tool is calculated. Machining tool trajectory generation processing 1
Execute 40.

In this straight machining tool trajectory generation process 140, the data processing unit 1 first generates offset machining area A7. B' is reduced to the inside of the machining area by the offset amount of the Sarai machining tool specified by the operator, and the offset machining area A' is created.
, B' is updated with the processing tool (processing 141).

This process 141 is performed as follows.

That is, as shown in FIG. 6, first, the outline of the processing area is extracted (process 301). In this process 301, an image is scanned in a fixed direction from a reference position, and the first pixel whose value is "1" is determined as a start pixel.

Using this pixel as a starting point, the outermost contour data is formed by the above-mentioned 8-connected vector tracing method. However, in this case, since a contour cannot be formed at a corner where the difference between the two vectors is 180 degrees or more, a changing pixel is further searched for in a counterclockwise direction. The angle formed by these two vectors is given by the following formula (
It can be calculated by calculating the inner product of two vectors as shown in 1)''.

e = cos-1(V, -V, /(IV, l-l v,
1)) -... (■)'Here, ■1 is the average vector of multiple (for example, 5) vectors up to the change pixel, and ■2 is the average value of the vectors from the change pixel. The average vector of multiple vectors in the forward direction is calculated.

When the contour line is extracted in this way, the result of judgment 302 is '/ES) when the contour line is extracted for the first time. Data (starting point position coordinates and vector data)
is stored (process 303).

Then, a processed mark is added to the pixels extracted as the contour line in process 301 to indicate that the process has been completed (process 3
04). However, in order to avoid dividing the processing area as much as possible, the processed mark is not added to areas where the contour lines are not separated by 2 bits or more. Pixels to which the processed mark is added and pixels to which the processed mark is not added can be distinguished by the relationship between the vector entering the pixel and the vector from that pixel to the next changed pixel.

Next, it is checked whether the contour line has been extracted for a predetermined number of pixels from the outermost frame (determination 305), and this determination 305
If the result is NO, the process returns to step 301, and in this case, the contour line that forms the boundary between the pixel to which the processed mark has been added and the pixel whose value is "1", that is, the processing area, is extracted and the processing area is sequentially processed. Pixels forming the inner contour line are extracted, and a processed mark is added to the extracted pixels.

Here, the number of pixels determined in the determination 305 is the number of pixels corresponding to the offset amount of the Sarai machining tool.

Therefore, at the time when this determination 305 is completed, a processed mark is added to the pixels located inside the outline of the outermost frame by the offset amount of the processing tool.

By the way, according to process 304, in order to make the processed area as continuous as possible, a processed mark is not added to areas where the contour lines are not separated by 2 bits or more, and In a portion that is inclined at 45 degrees with respect to the scanning direction, a processed mark is added only to a portion that is 17a times as large as the range that is actually machined by the Sarai machining tool.

Therefore, in order to accurately form the area to be actually machined with the Sarai machining tool, vector data representing the outline of the outermost frame stored in Process 303 is read (Process 306).
, 2 of the number of pixels corresponding to the offset amount of the Sarai machining tool
When the center of the processing date drawn with double the diameter is moved along the outline of this outermost frame, pixels that belong to the area included inside the processing date and have not been marked with a processed mark are processed. Correct the processing area by adding marks (processing 307
).

As a result, a processed mark is added to the pixels of the portion corresponding to the accurate offset amount of the machining tool.

Next, in the updated processing area, the boundary line (contour line) between the pixel to which the processed mark has been added and the pixel whose value is "1" is calculated in the same manner as in process 301 in FIG. 6, The data of the extracted contour line is stored as the outermost frame tool trajectory (process 143).

Next, the process shown in Fig. 6 is applied to the number of pixels corresponding to the overlap amount of the side machining tool, and the time when the side machining tool passes the outermost frame tool trajectory and the one tool path inside the side frame tool are Adds a processed mark to pixels corresponding to the amount of overlap when passing through (processing 1
43). In addition, in this process 143, a process is performed so that continuity is not lost so that the tool trajectory becomes a single stroke.

Such processes 141, 142, and 143 are repeatedly executed until they are applied to the outermost frames of all machining areas (loop of judgment 144), and the outermost frame tool locus of the horizontal machining area of each machining area is calculated.

Next, the process of FIG. 6 is applied to the number of pixels corresponding to the offset amount of the Sarai machining tool to extract an offset line for machining the inner machining area (process 145).
A process 146) is performed to calculate a tool trajectory corresponding to this offset line using a method similar to process 301 in the figure, and the process shown in FIG. Process 147) to add a processed mark to the pixels of
Steps 46 and 147 are repeatedly executed (loop of judgment 148) to calculate a tool trajectory for machining the horizontal machining area other than the outermost frame.

In this manner, the tool trajectory of the slanting tool in all machining areas is calculated by the slanting tool trajectory generation process 140.

As a result, tool trajectories for machining the machining areas A' and B' are formed as shown in FIG. 2(c) and stored in the storage device 4. In addition, in the figure, what is shown by a broken line is a contour machining tool trajectory, and what is shown by a solid line is a contour machining tool trajectory.

Incidentally, it is also possible to perform smoothing processing on the trajectory of a machining tool for machining the outermost frame of the offset machining area.

That is, in this smoothing process, the tracking vector formed in process 142 is formed by combining a circle, a long straight line about 10 times the tool diameter, a vertex, a short straight line, a circular arc, and a free curve.

In such smoothing processing, as shown in FIG. 7, first, the circular portion of the outline is determined (processing 401).

In this process 401, three arbitrary points on the contour are selected, the center of a circle passing through these three points is calculated, a plurality of other three points are selected as appropriate, a plurality of centers are calculated, and these plural points are calculated. When a circle having a radius from the center to the contour line is drawn, it is determined whether the contour line coincides with the circle based on the following equation (II).

C: (x2+y') /y...(II) However,
C is the center.

Here, since a circle forms one closed curve, it is checked whether all the trajectories forming one contour line have been completed by determining this circle (determination 402), and if the result of this determination 402 is NO, the next Proceed to processing.

Next, a straight line that is ten times longer than the length of the Sarai machining tool is calculated (process 403). In this process 403, an average vector of five unit vectors is formed, and a temporary linear period is calculated from the vector angle of the average vector based on the linear equation ([1)].

Next, an integrated value SA and an integrated value SB of the absolute value of the distance ΔQ1 between each pixel data and the temporary straight line calculated by equation (III)
are calculated based on equations (IV) and (V), respectively, and based on the results, it is determined whether the temporary straight line calculated using equation (III) can be identified as an actual straight line.

ax+by+c=o −urnφ(m)SA
= Σ1ΔQsl ... (TV) i 5B = ΣΔQl ... (V) l 1 Furthermore, a histogram of the direction of the vector is further formed,
If the histogram has 2-3 peaks, that section is determined to be a straight line, and if the histogram has more peaks, it is determined to be something else.

Next, vertices appearing in one outline are determined for portions that were not determined to be circles or long straight lines in processes 401 and 403 (process 404).

In this process, the average vector formed in process 403 is substituted into the above-mentioned equation (1)'' to calculate the angle formed by the two average vectors, and the vertex is determined based on the calculation result.At this time, the average vector Depending on the starting point of the calculation, there is a risk that the vertex may be incorrectly determined. Therefore, in parts where the angle formed by the two average vectors is sharp to some extent, the starting point of the calculation of the average vector is sequentially changed, and the angle formed by the two average vectors is It determines the state where the angle is sharpest and most stable, and thereby detects the appropriate vertex.

Next, the section between the end point of the straight line calculated in step 403 and the vertex calculated in step 404, or the section between the vertices that can be determined to be a straight line, is calculated using the same criteria as in step 403. (process 405).

Next, the arc portion is calculated for the sections that were not processed in processes 401, 403, 404, and 405 (process 40
6).

In this process 406, a temporary circular arc section is calculated in substantially the same manner as in the process 401, and the temporary center of this temporary circular arc section is calculated based on the coordinates of 8 points of the temporary circular arc section, and from the temporary center. A circle equation such as the following equation (VI) is formed.

(x-xo)”+(y-yo)”=r”...(V
I) Then, calculate the difference between this temporary arc and the actual pixel coordinates using the above formulas (IV) and (V), and check whether the temporary arc section is appropriate based on the calculation result. At the same time, the radius is determined.

Finally, a free curve made of a spline curve is applied to the sections that were not targeted in processes 401, 403 to 406 (process 407).

In this way, the outermost frame tool locus of the Sarai machining tool is smoothed. Note that the method for smoothing the tool trajectory is not limited to the method described above.

[Effects] As described above, according to the present invention, an offset line of a machining shape formed by a line drawing is formed, this is stored as a locus of a contour machining tool, and the pixels forming the offset line are
At the same time, a second identification code is added to the pixels forming the vertices and individual lines appearing in the offset line by detecting them. Then, when the processed shape is scanned in a certain direction, the pixels to which the first identification code is added that intersect with the scanning line are counted, and areas where the count value is an odd number are determined to be pixels inside the processed area. Areas with even count values are identified as pixels outside the processing area, and the parts identified as inside the processing area are filled in, thereby forming the processing area, so the processing area is determined from the processing shape formed by the line drawing. This has the effect of being able to appropriately form the . In addition, a tool path is generated for machining the contour part of the machined shape with a contour machining tool with a small diameter, and other parts with a machining tool with a large diameter, so it is possible to use a tool for efficient cutting. The effect of being able to generate a trajectory can also be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a data processing device according to an embodiment of the present invention, FIGS. 2(a) to (c) are explanatory diagrams showing how a tool trajectory is generated from a line drawing, and FIG. 4 is a flowchart showing the process for generating a tool path.
The figure shows flowchart 1 showing an example of processing for filling.
, FIGS. 5(a) to (d) are explanatory diagrams showing the state of filling, FIG. 6 is a flowchart showing an example of processing for forming the part to be cut with a tool, and FIG. 7 is an example of smoothing processing. This is a flowchart. 1...Data processing unit, 2...Keyboard, 3...
Screen display unit, 4...Storage device, 5...Video RAM
(Random access memory), 6... Screen control unit. Agent Patent Attorney Makoto Hijiri Figure 1 Figure 2 (a) (b) (C) Figure 3 Figure 4 Figure 5 (a) (b) (c) (d
) Figure 6 Figure 7 Procedure Amendment Band (Voluntary) July 7, 1985

Claims (1)

[Claims] The machining shape to be machined by a numerically controlled machine tool is formed as a line drawing, an offset line corresponding to a contour machining tool for machining the contour of the machining shape is formed, and this is memorized as the trajectory of the contour machining tool. adding a first identification code to the pixels forming the offset line, detecting vertices and individual lines appearing in the offset line, and adding a second identification code to the pixels forming the vertices and the individual line; When the processed shape is scanned in a certain direction, pixels to which the first identification code is added that intersect with the scanning line are counted, and areas where the counted value is an odd number are determined to be pixels inside the processed area. Areas where the count value is an even number are determined as pixels outside the processing area, and a third identification code is added to the pixels determined to be inside the processing area, and this third identification code is added. A two-dimensional tool that determines a pixel area as a machining area and forms a one-stroke two-dimensional tool trajectory based on an offset amount and an overlap amount of an area machining tool that processes a machining area other than the contour line. Tool path generation method.