JPH01155403A - Method for generating processing path - Google Patents

Abstract

PURPOSE:To reduce a load on an operator at the time of performing automatic programming by generating a tool path by inputting the shape of a raw material to a computer by using a three-dimensional visual device, comparing it with the final shape to be processed, and deciding an area to be removed. CONSTITUTION:The shape of the raw material 14 is recognized by a three- dimensional visual system 16, and recognition shape information is inputted to an electronic computer 17. Meanwhile, information with respect to the final shape to be processed by a CAD system 13 based on the dimensional drawings of the plan view, the front view, and the side view of a workpiece 11 having the final shape to be processed are inputted, and the computer 17 compares both input, and decides the area of the material 14 to be removed, then, generates the tool path, and performs the automatic programming. In such a way, it is possible to input the shape of the raw material automatically and accurately, and also, to decide the area to be processed automatically, and to reduce the load on the operator remarkably in the automatic programming.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for generating a machining path, and particularly to a method for automatically generating a machining path using a three-dimensional visual device.

<Prior Art> The automatic programming device C that automatically creates an NC nib program is capable of automatically creating an NC nib program using data inputted by an interactive method or the like.

By the way, in such conventional automatic programming, 1
．． t. In order to obtain a workpiece having the desired final machined shape, the operator had to interactively instruct the areas to be deleted from the material shape one by one. In other words, conventionally, an operator compares the material shape with the final machined shape, determines where and in what order the material should be machined in order to obtain the final machined shape, and specifies the machining area based on the judgment results. I had to.

<Problems to be Solved by the Invention> As described above, in conventional automatic programming, there is a problem in that the operator has to perform manual work on each machining area, making the automatic programming operation troublesome.

In addition, in conventional automatic programming, accurate dimensional figures etc. are prepared for the final machined shape, but generally such figures are not prepared for the material shape, or even if they were prepared, However, it does not exactly match the real thing. For this reason, when specifying the machining area, the operator must take safety into consideration and specify the area by assuming that the material is thicker than the actual material, leading to the problem of waste being included in the tool path. .

From the foregoing, an object of the present invention is to provide a machining path generation method that can automatically and accurately input the shape of a material, automatically determine a machining area, and generate a machining path.

Means for Solving the Problems> FIG. 1 is a block diagram of an automatic programming system according to the method of the present invention.

11 is a workpiece having a final machined shape, 13 is a CAD system with a modeler function, 14 is a material, 16 is a three-dimensional visual system, and 17 is an electronic computer.

Operation> The three-dimensional shape of the material 14 is input into the computer 17 using the three-dimensional visual system 16, and the CAD system 1
3, the three-dimensional final processed shape is input into the electronic computer 17.

The electronic computer 17 compares the inputted final machined shape and the material shape, determines the region to be removed from the material 14 to obtain the final machined shape 11, and generates a working path of the processing tool according to the removed region.

<Embodiment> FIG. 1 is a block diagram of an automatic programming system according to the method of the present invention.

11 is a workpiece having a final machined shape; 12 is a design drawing sheet on which dimension drawings of the plane, front, and side surfaces of the final machined shape are drawn; and 13 is a three-dimensional diagram of the workpiece 11 based on the dimensions of each figure. A CAD system equipped with a modeler function that recognizes and outputs the original shape, 14 is the material, 15 is a turntable that rotates the material, 16 is a three-dimensional visual system that automatically identifies the three-dimensional shape of the material, and 17 is a three-dimensional An electronic computer receives the original final machining shape and material shape, automatically determines the machining area, and generates a machining path (NC program); 18 is a disk device; and 19 is a printer.

The CAD system 13 includes a keyboard KB, a graphic display device CRT that displays a dialogue screen, and a mouse M.
SE, a workpiece 11 that is configured with a disk device, a communication interface, and a processing unit (not shown), and that automatically has a final machined shape based on each dimension of a three-view diagram input from a keyboard or the like according to predetermined rules. It has a modeler function that recognizes and outputs three-dimensional shapes (edge lines, etc.).

The three-dimensional vision system 16 is a floodlight or projection @PRJ
It is equipped with a camera CMR, an image processing device IPR, and a material 14
The system captures the two dimensions of the material, performs image processing, and outputs the three-dimensional shape of the material.

The principle of this three-dimensional visual system is (i) A gray code pattern light is projected by a projector PRJ to represent the space as a code, and the image is captured by a camera CMR to identify the object (material) using the principle of triangulation. 3D information (image)
(ii) Project the slit light, similarly calculate the three-dimensional position of the illuminated part using the principle of triangulation, scan the slit light with a rotating mirror, and obtain the three-dimensional position of one screen. (2) The distance to the object (material) is calculated from the phase difference between the transmitted wave and the reflected wave of the amplitude-modulated laser beam, and this laser beam is converted into a two-dimensional image. 3D information for one screen (
Some methods are known to obtain images (images). The method (i) is described in "Pages 1565 to 1566 of the Journal of the Information Processing Society of Japan's 33rd (late 1986) National Convention (High-speed distance image measurement using a liquid crystal projector)."

The image obtained by the three-dimensional vision system 16 is called a distance image because each pixel represents the distance to the object, but the object and the background can be easily separated if there is a certain distance or more. There is a characteristic that. Therefore, the three-dimensional vision system 16 can obtain the three-dimensional shape of the object (material) 14 and input it to the electronic computer 17.

By the way, the three-dimensional vision system 16 can only obtain three-dimensional information when the material is viewed from one direction, but by sequentially rotating the turntable 15 at a certain angle to capture and synthesize images, the three-dimensional information of the entire material can be obtained. shape can be obtained. The method of synthesizing each image obtained by rotation to obtain an overall three-dimensional shape is described in rJAACE '87.
-5 31st System and Control Research Presentation Conference Journal No. 11
Pages 1 to 112 (Use of Distance Image Generation System for CAD Input)''.

FIG. 2 is a flow chart of processing for generating a three-dimensional shape of a material by the image processing device IPR.

First, a distance image is obtained (step 101).

Note that the material 11 is placed on the turntable 15 so that the three-dimensional shape of the material 11 can be captured from several directions. In this case, if a black cloth is placed over the turntable 15, the turntable itself/distance image will not appear.

Next, the material and background in the distance image are separated (step 103). Note that if a certain distance exists between the background and the object, a distance image within a specific range in the optical axis direction of the camera CMR can be regarded as a distance image of the material and easily separated.

Once the distance image of the material is determined, the image processing device IPR binarizes the distance image and projects it onto the vertical and horizontal axes of the display screen. This creates a two-dimensional object (material)
Understand the area of existence. After that, the existence area is set to m
Divide into small regions of X m pixels (step 105).

Note that m x m may be, for example, 5X5, 7X7, etc.

Next, find the normal vector of each small region (step 1
07). Note that the normal vector of a small area can be found as follows.

The plane equation is A-x+B-y+C-z+D=0 z =-A-x/C-B-y /C-D/C (C≠0)
Expressed as In addition, C=0 means a plane parallel to the Z axis,
Therefore, it is assumed that the plane expressed by the above formula is not parallel to the Z axis. This is because the optical axis of the camera is the Z axis.
Normally, such planes are invisible. Here, if -A/C=town, -B/C=b, -D/C=d, the plane equation is z=a, x+b1+y+d.

It can be transformed into As a result, the normal least squares equation becomes: Note that k is the number of pixels in the small area, (x, t y
lt''+) is the coordinate value of the first pixel.

Σz, = a, Σx, +b, Σy, + to -d1(i
=1~k) Σx, z, =a, Σx? +b, Σx, y, +
d, Σx, (i=1~lc)ΣVlzl"'lΣx
,y,+b,Σy? +d, Σyl (i=1~k) Expressed using Gaussian symbols, (Σ" + yi → [xyl, etc.)
It will look like this:

[X a, + [yl b, +k - d, =
[zko[xx] a, + [xyl b1+ [xl
d, = [zx] [xyl a, + [yyl b1+
[yl d,= [yzlThis simultaneous equation al,
When solving for b,, d, "1=(uyy '"
! If u,,' u,,) /V.

b,= (u,, eu,, u,, −u,,) /
v.

d1= ([z] −[xl a, −[y co bl
)/, however, v = u meeting u −u uX+1=[” ] 2−k[xx] p u−y
= [xl [y] -k[xy] e etC- After finding a,, b,, d, the plane equation a, ・x+b, ・y−z+d, =O is converted to the standard form a
,'・x+b,'・y+a,'・z−d'=
Correct it to 0. That is, a1' = a, /Np b,' = b, /N, c,'
=-1/N, d,' =-d, /NN= At this time, vector (a,', b1', c,'
) is the unit normal vector of this plane equation.

Once the normal vector of each small region is determined, the unit normal vectors of adjacent small regions are compared, and if it is within a tolerance range, the same plane regions are considered to be the same plane and the same plane regions are integrated to obtain the entire plane. (Step 109).

As described above, once the planar regions have been integrated, adjacent planes are estimated taking into account the positional relationship of the centers of gravity of each planar region, and the intersection line between the planes, in other words, the ridgeline of the material is determined (step 111
). Note that the intersection line is expressed as a combination of two plane equations. Also, although the lines of intersection may not intersect with each other, the midpoint where the two lines of intersection are closest is considered to be the vertex.

When the above processing is completed, the turntable 15 is rotated by a predetermined angle (=90°), the processing from step 101 onward is repeated, and the obtained three-dimensional shapes are combined to form the overall three-dimensional shape of the material. get.

FIG. 3 is a flowchart of processing performed by the electronic computer 17 to generate a machining path.

When the electronic computer 17 receives the three-dimensional final processed shape from the CAD system 13 and the three-dimensional shape of the material from the three-dimensional visual system 16, the electronic computer 17 inputs the final processed shape into the material shape so that the final processed shape is included in the material shape. The relative positional relationship of shapes is determined (step 201).

Next, the position where the material is fixed on the processing table of the machine,
The posture is determined (step 203).

After that, the relative positional relationship data and the material position/orientation data on the processing table are used to determine the region from which the material should be removed in order to obtain the final shape, and the tool path (processing path) for removing the region is determined. (step 205). still,
When determining the tool path, the allowable depth of cut of the tool, cutting width, etc. are required, but these are assumed to be input separately.

Thereafter, the processing in step 205 is performed until the tool paths of all tools used to process the material in the current posture (for example, a posture according to the rotational position of the processing table) are determined (
Step 20? ), if the tool paths of all tools are determined,
Check whether machining has been completed in all postures (machining surfaces), and if not, proceed to step 20 for a new posture.
3 and subsequent steps are repeated, and if completed, the machining path generation process is ended.

Incidentally, when the computer 17 completes the creation of the processing history @ (NO-cannibal program), the computer 17 outputs the NC-cannibal program to a floppy disk via the disk device 18 or prints it out by the printer 19 as appropriate.

<Effects of the Invention> According to the present invention, the material shape of the workpiece is input into a computer using a three-dimensional visual device, the final processed shape and the material shape are compared, and the material shape is determined in order to obtain the final processed shape. Since the area to be removed is determined from the area to be removed and the tool path is generated according to the removed area, the burden on the operator can be significantly reduced during automatic programming. Furthermore, since the material shape can be input accurately, the generated tool path can be easily Be able to eliminate waste.

[Brief explanation of the drawing]

Figure 1 is a block diagram of the automatic programming system according to the method of the present invention, Figure 2 is a flowchart of the processing of the image processing device to obtain the three-dimensional shape of the material, and Figure 3 is the flowchart of the processing of the image processing device to obtain the machining path. It is a flowchart of processing. 11...Workpiece with final machined shape, 13...CAD system with modeler function, 14...Material, 16...
Three-dimensional visual system, 17...Electronic computer patent applicant Chiki Saito, agent for Fanuc Corporation, patent attorney Figure 2 Figure 3

Claims (1)

[Claims] A step of inputting the three-dimensional shape of the material into a computer using a three-dimensional visual device, comparing the three-dimensional final processed shape with the material shape, and removing it from the material to obtain the final processed shape. 1. A machining path generation method comprising the steps of: determining an area to be removed from a material; and generating a path for a machining tool according to the area to be removed from a material.