JPH01292577A - Generating system for intersecting point in cad system - Google Patents

Abstract

PURPOSE:To improve the production efficiency of the analysis data with an intersecting point generating means by selecting the coordinate data at a coordinate data selecting part, producing the characteristic formulas of each element at a characteristic formula production part, and generating en bloc the intersecting point coordinates at an intersecting point calculating part respectively. CONSTITUTION:When a command is given to a processor 10 from an input device 13 for generation of intersecting point, an intersecting point generating means 11 is actuated and an area designating part 110 holds a designated area. A coordinate data selecting part 111 takes the graphic data out of a graphic data file 14. These graphic data are selected by the part 110 and stored in a coordinate data store part 121. When all coordinate data are selected, a characteristic formula production part 112 is started and produces the characteristic formulas of each line, the circles, etc., from the data stored in the part 121 to store these formulas into a characteristic data store part 122. Then an intersecting point calculating part 113 is started to carry out the arithmetic for acquisition of intersecting points and stores the result of said arithmetic into an intersecting point data store part 123. These intersecting point data can be displayed on a display device 15.

Description

[Detailed Description of the Invention] [Summary] A method for generating intersections of line segments for use in analysis of design structures in CAD systems for mechanical design. The purpose of this project is to provide an intersection generation method in a CAD system that can obtain and display the coordinates of a large number of intersection points at once. The intersection generation means activated by the intersection generation command selects the coordinate data of the graphic element included in the specified area from the graphic data file by the coordinate data selection section, and then uses the characteristic expression creation section to generate the element based on the selected coordinate data. By creating characteristic expressions for each element, and by combining the plurality of characteristic expressions in the intersection calculation section, the intersection coordinates between elements are calculated for all combinations of characteristic expressions, thereby generating intersection coordinates at once. Configure.

[Industrial Application Field] The present invention relates to a line segment intersection generation method for use in analyzing a design structure in a CAD system for mechanical design.

In recent years, CAD (computer-aided design support system) technology has become widely used, and is also being used for various processes in mechanical design. Among them, in mechanical design analysis (for example, strength analysis), it is sometimes necessary to detect the coordinates of an area formed by multiple lines, circles, etc. I specified a line or circle and found the intersection coordinates. However, conventional methods require time and effort to find intersections within a certain area for figures that include many lines and circles, so improvements are desired [Conventional technology] Conventional mechanical design methods CAD has a point generation function as a basic function.

The figures handled by mechanical design CAD systems include various elements (straight lines, circles, etc.), and finding the intersections between these elements is necessary for design or for analyzing mechanical properties. becomes.

Specifically, such intersection point data of graphical elements is necessary data when using the finite element method to analyze the mechanical strength of component parts in mechanical design. In the finite element method, the reaction to a load applied to an object of a certain size is divided into minute regions (squares, triangles, etc.) and the state of each minute region is collected to understand the effect on the whole. It is. In this case, each coordinate value of the minute area is obtained by finding the intersection of the lines.

These lines or circles are called "elements", and when finding the intersection of two elements, in the conventional method, the two
By selecting and inputting coordinate values representing two elements (coordinate values of X and Y axes), an intersection point between two elements is generated.

To explain specifically, the example of the figure shown in FIG. 4 is line 11 and I! 2 and circle C, and is displayed on the display device of the CAD system. Now, if you want to find the intersection of lines 11 and 12, select lines 11 and 12 (using a light pen, etc.) and give the instruction to find the intersection.
Find and display the coordinate data of point A. Similarly line 11
When circle 1 is selected and specified, intersection B is found and displayed.

[Problems to be Solved by the Invention] According to the above-mentioned prior art, the coordinates of the intersection point are determined by selecting two elements related to the intersection point, so there are few problems when the number of elements is small, but for example, Mouth in Figure 4,
A large number of lines I11 in the Y-axis direction (vertical direction) as shown in
~1m and the intersections generated by lines L1 to Ln in the X-axis direction (horizontal direction) and within the specified area (circle at the end of Figure 4)
When finding the intersection, it is necessary to repeat the simple operation of selecting two elements and finding the intersection, which is a problem in that it takes time and effort.

SUMMARY OF THE INVENTION An object of the present invention is to provide an intersection point generation method in a CAD system that can collectively determine and display the coordinates of a large number of intersection points occurring within a certain area of a figure including a large number of lines, circles, etc.

[Means to solve the problem] FIG. 1 shows a basic configuration diagram of the present invention.

In FIG. 1, 10 is a processing device, 11 is an intersection generating means, 12 is a memory, 13 is an input device, 14 is a graphic data file,
Reference numeral 15 represents a display device, and the intersection generating means 11 includes an area specifying section 110, a coordinate data selecting section 111, and a characteristic expression creating section 112.
and an intersection calculation unit 113.

The present invention selects element data of a specified area in a specified figure, creates characteristic expressions representing each straight line, circle, etc. based on the coordinate data, and then combines the characteristic expressions to find a solution (intersection point). Sequentially perform the calculations to find
By performing calculations on all combinations, all intersection points are obtained and output.

[Operation] When a command to generate an intersection point is inputted from the input device 13 in FIG. 1 along with designation of a target region (range of figures) for which an intersection point is to be found, the intersection generation means 11 in the processing device 10 is activated. do. Area specifying unit 110 of intersection generating means 11
holds the input specified area. Coordinate data selection section 1
11 is activated by activation of the intersection generating means 11, extracts graphic data from the graphic data file 14, selects graphic data (coordinate data) within the area specified by the area specifying unit 110, and stores the data in the coordinate data storage unit of the memory 12. 121. When all the coordinate data is selected, characteristic equation creation section 1
12 is activated and creates characteristic expressions (equations) for each line, circle, etc. from the data in the coordinate data storage section 121 of the memory 12. As a result, each obtained characteristic expression is stored in the characteristic expression data storage section 122 in the memory 12.

Next, the intersection calculation unit 113 is activated, combines the characteristic equations of each line or circle from the characteristic equation data storage unit 122 in the memory 12, performs calculations to find intersections, and transfers the calculation results to the intersection data in the memory 12. It is stored in the storage unit 123. After performing such calculations for all combinations of characteristic expressions, the intersection of the target areas is located in memory 1.
2 is obtained in the intersection data storage unit 123. The intersection data can be output to the display device 15 and displayed, and can be used as needed.

[Example] Fig. 2 18+ shows a processing flow diagram of an example of the present invention.
Figure (bl) shows a hardware configuration diagram of the embodiment.

FIG. 2 (in BL, 20 is a central processing unit (indicated by CPU), 21 is a memory, 22 is a magnetic disk device, 23 is
2 represents a keyboard with a display device, and 24 represents a printer.

The process shown in FIG. 2 18+ starts when a command to generate an intersection is input from the keyboard 23 with a display device together with an area instruction. The data is taken out and stored in the memory 21, and the coordinates of the elements included in the designated area are extracted and stored in the coordinate area in the memory 21 (+81200 in FIG. 2). Next, an equation of a straight line or circle is obtained based on the coordinate points of each element (straight line or circle) stored in the coordinate area, and processing is performed to store it in the equation area of the memory 21 (step 210). Once each equation has been found for all elements, the intersection coordinates are obtained by combining the equations corresponding to each element and performing calculations to find the solution to the X and Y coordinates.
The results are stored in the area for intersection coordinates in the memory 21. When the intersection coordinates are determined for all combinations of equations (230), the determined intersection coordinate values are stored in the memory 21.
The process is completed by reading out the information from the file and outputting it to the keyboard with display device 23 for display.

FIG. 3 is a diagram showing a concrete example of the process of generating an intersection point.

The processing in Figure 3 corresponds to the content shown in Figure 2 18+, and
It is assumed that four lines, lines 1 to 4, as shown in the display image B, are extracted from the mechanical design file in step 200 of FIG. 18+. The coordinate data of the four extracted lines (in this case, the coordinates of the starting and ending points of the straight line) is A,
The contents are shown in and stored in memory. When equations for each line 1 to 4 are created using this coordinate data, the equation shown in FIG. 3 C0 is obtained (based on mathematical principles).

Next, calculations are performed to find the intersection between these lines 1 to 4. To give an example of calculating the intersection between lines 1 and 3, the simultaneous - When solving the following equation, the coordinates x and y of the intersection point are the third
The values are as shown in the diagram. Do this calculation on lines 1 and 4
, between line 2 and line 3, and between line 2 and line 4, four intersection points Xa YA"
1 is required. When the four intersection points are displayed together with the figures of the four lines, the intersection points are highlighted as shown in Figure 3F, and the coordinate data of the intersection points can be stored in the memory if necessary.
It can be taken out from 1.

[Effects of the Invention] According to the present invention, it is possible to streamline the process of creating analysis data using point information in graphic information drawn with a CAD system. In addition, in the CAD system,
Some tools have a function that allows you to delete points such as intersections all at once, which is effective when restoring intersections based on element data if you use this function incorrectly.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of the present invention, Fig. 2 t8+ is a processing flow diagram of the embodiment, Fig. 2(b) is a hardware configuration diagram of the embodiment, and Fig. 3 is a detailed processing flow of intersection generation. Example 1: FIG. 4 is an explanatory diagram of a conventional intersection generation method. 10 in FIG. 1: Processing device 11: Intersection generating means 12: Memory 13: Input device 14: Graphic data file 15: Display device 110: Area specification section 111: Coordinate data selection section 112 = Characteristic expression creation section 113: Intersection calculation Department

Claims (1)

[Claims] In an intersection generation method in a CAD system that processes graphic data for mechanical design, an intersection generation means (11) activated by an intersection generation command specifying an area from an input device is configured to generate a graphic data file (14). ), the coordinate data of the graphic element included in the specified area is selected by the coordinate data selection unit (111), and based on the selected coordinate data, the characteristic expression creation unit (11
In 2), a characteristic equation for each element is created, and the intersection calculation section (1
In 13), the intersection coordinates between elements are calculated by combining the plurality of characteristic expressions, and the intersection coordinates are generated at once by calculating the intersection coordinates for all combinations of characteristic expressions. method.