JPS6047631B2 - interactive plotting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an interactive drawing device capable of analyzing the characteristics of a designed object obtained by computer-aided design (CAD).

2. Description of the Related Art Conventionally, there have been CAD (so-called interactive drawing devices) that use graphics to design while an operator and a machine interact with each other via a keyboard, digitizer, joystick, drawing display, etc. with the help of a computer. In this type of equipment, more efficient design can be achieved if characteristic values such as surface area, volume, mass, center of gravity, or moment can be ascertained at the design stage before processing the designed object into an actual object. . However, in general, conventional devices of this type can only design objects with uniform density or geometric objects with density 1, and it is impossible to design objects with non-uniform density. The drawback was that it was not possible to analyze the characteristics of the designed object at the stage. The present invention eliminates such drawbacks and devises a method for inputting data to a computer in order to make the computer recognize that the material property values of a designed object differ depending on the boundary line or boundary surface. The aim is to realize an interactive drawing device that can design objects with non-uniform material property values and analyze their properties at the design stage.

The present invention will be explained in detail below using the drawings.

FIG. 1 is a configuration explanatory diagram showing an embodiment of an interactive drawing device according to the present invention. In Figure 1, 1 is a calculator, 2
3 is a keyboard, 3 is a message display, 4 is a cursor control, an arm, and 5 is a cathode ray tube display (hereinafter referred to as CRT). The keyboard 2 is composed of alphanumeric keys, function pushbuttons, etc., and each key and pushbutton is capable of generating encoded information. Drawing information and information regarding the job of the apparatus can be input to the computer 1 using the keyboard 2. The message display 3 is, for example, LE
Consists of an alphanumeric display that interactively guides the operator step-by-step through the operating procedure and displays the status of the device, cursor control, and cursor operated by arm 4 (not shown). It displays the location of the computer 1 and information regarding the job being executed on the computer 1. The cursor control arm 4 is a joystick for positioning the cursor by moving it arbitrarily in the x and y axis directions, and the coordinate position of the cursor operated by this is displayed on the CRT 5 via the calculator 1. At the same time, a numerical value is displayed on the message display 3. The operator can draw a design drawing of a desired object on the CRT 5 by appropriately operating the arm 4 and keyboard 2 while interacting with messages displayed on the display 3. Further, if desired, it is also possible to convert the figure and draw it. The operation of the apparatus of the present invention with such a configuration will be described using as an example a case where the mass of a secondary object with non-uniform density is analyzed. When drawing and analyzing a two-dimensional object surrounded by boundary lines #1, #2, and #3 as shown in Figure 2, whose internal surface densities are ρ1, ρ2, and ρ3, respectively, on a CRT5. Describe the operation step by step. (1) When the drawn boundary line #1 is selected by operating the cursor and the keyboard 2, an inquiry message corresponding to 2 external density=2 is first displayed on the message display 3.

The operator inputs the external density 0 using the keyboard 2. When this data is read into the computer 1, a message corresponding to "Internal Density=" is displayed, and the value of the internal density ρ1 in this case is then entered using the keypad. In Calculator 1, boundary line #1! Calculate the internal area S1 and define the difference function SGNl=ρ1-0=ρ1 between the two densities. (2) In the same manner as described above, input the values of the external density ρ1 and the internal density ρ2 for the boundary line #2. In the calculator 1, the area S2 inside the boundary line #2 is calculated twice, and a difference function SGN2=ρ2−ρ1 is defined. (3)
In the same way as above, the external density ρ2 is calculated for the boundary line of #3.
and the value of the internal density ρ3, the calculator 1 calculates the internal product S3 of the boundary line #3, and also calculates the difference function SGN.
, = ρ, −ρ2 are defined.

(4) A command from the keyboard 2 causes the computer to calculate the mass M of the two-dimensional object with non-uniform density shown in FIG. 2 based on the following equation.

The first term in the above equation represents the mass between boundaries #1 and #2, the second term represents the mass between #2 and #3, and the third term represents the mass inside #3.

In this way, the mass M of any shape formed with any areal density can be easily determined at the design stage.

In addition, in the embodiment, the area and difference function were defined by giving the external and internal densities to one boundary line, but the invention is not limited to this. For example, it may be configured with uniform density. It is also possible to select the boundary line of the area to be covered, define its area and density, and calculate the mass.

Furthermore, by specifying other characteristic values instead of the areal density, it is possible to analyze the characteristics related to these values. For example, if Young's modulus is specified instead of areal density, it can be applied to analyze the properties of composite burrs in material mechanics. Furthermore, the method can be applied to three-dimensional objects by using boundary surfaces instead of boundary lines. However, especially for a three-dimensional object such as a rotating body, its characteristics can be analyzed by treating it as a two-dimensional figure by cutting it along a plane that includes the axis of rotation, without treating it as a three-dimensional object. Furthermore, in addition to the mass, it is also possible to determine the true center of gravity, moment of inertia, and rotational radius of a designed object with non-uniform density in two or three dimensions. As explained above, according to the interactive drawing device of the present invention, the cursor control arm 4 and the keyboard 2 are operated for a designed object with non-uniform material property values, and the message output from the calculator 1 is By providing information in an interactive format, it is possible to easily analyze the characteristics of a designed object at the design stage before processing it into a real object.
The effect is great in practical use.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of an interactive drawing device according to the present invention, and FIG. 2 is an explanatory diagram of the configuration of a designed object with non-uniform areal density. DESCRIPTION OF SYMBOLS 1...Calculator, 2...Keyboard, 3...Message display, 4...Cursor control arm, 5...Cathode ray tube display.

Claims (1)

[Scope of Claims] 1. A computer, a message display that interactively guides an operator through operating procedures and displays information regarding the status of the device, the position of the cursor, and jobs being executed on the computer; Equipped with a cursor control arm to drive, a keyboard to input necessary processing related to the job, and a cathode ray tube display to display the figure designed based on the drawing data output from the computer. An interactive drawing device characterized in that material property values are entered from a keyboard in response to messages displayed on a boundary line or boundary surface of a designed object having a value, and the properties of the designed object are analyzed at the design stage. . 2. The interactive drawing device according to claim 1, wherein material characteristic values for the outside and inside of the boundary line or boundary surface of the designed object are inputted.