JP3175337B2 - How to create robot machining path data - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of preparing machining path data for a teaching playback type robot.

[0002]

2. Description of the Related Art FIG. 11 is a view showing an example of a weld bead A, and W is a work such as an iron plate. Conventionally, when finishing the welding bead A by a robot, the following method has been used. In FIG. 12, 3b is a robot arm, 24 is a robot hand, and a motor 26 is attached to the robot hand 24 via a linear motion mechanism 25. Further, a tool chuck 27 attaches a rotating shaft of the motor 26 to a shaft 29 of a disc-shaped grindstone 29.
a is attached. And the grinding stone 29 is the motor 2
While being rotated by 6, it is sent in the direction of arrow B. At this time, a force in the direction of arrow C is applied to the motor 26 by a spring or an air cylinder (not shown) inside the linear motion mechanism 25. Thus, the weld bead A
Finish processing is performed.

On the other hand, the robot's control device is instructed in advance on the positions of the starting point and the ending point (in some cases, a passing point) of the machining. The control device creates machining path data for a path connecting those points by linear interpolation or circular interpolation. Then, the grindstone 29 is moved at the designated speed based on the created machining path data.

[0004]

According to the above-mentioned conventional robot, the grindstone 29 is merely pressed at a constant pressure by a spring or an air cylinder (not shown). It cannot be guaranteed that only Bead A is processed. No matter how much the processing conditions are limited, the size of the weld bead A, the processing capability of the grindstone 29, the relative position between the weld bead A and the grindstone 29, the orientation of the upper surface of the work W (see FIG. 9B), etc. Therefore, the weld bead A is left behind (see FIG. 6).
(See FIG. 7B), and it is inevitable that the upper surface of the work W is dug (see FIGS. 7B and 8B).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in view of the above-mentioned circumstances. An object of the present invention is to provide a route data creation method.

[0006]

In order to solve the above problems SUMMARY OF THE INVENTION, in the present invention, the data creation method of processing paths of teaching playback type robot, segment path by entering the start data and end data First to determine
And the radius of two arcs having different diameters from each other , and
A second step of inputting two data any of the three data of the radius of the difference of the two arcs, the first Engineering
And a third step of calculating a path that moves from a start point to an end point while spirally turning based on the section route determined in the second step and the data input in the second step .

[0007]

According to the method of the present invention, a path that moves from the start point to the end point while spiraling is created. Then, by moving the grindstone along the created path, it is possible to reduce the remaining of the weld bead and the digging of the work to a less conspicuous range.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing a configuration of a robot system to which the machining path data creating method according to the embodiment is applied. In the figure, 1 is a computer,
Various data for controlling the robot 3 is created. 2
Is a robot controller that controls the robot 3 based on various data created by the computer 1. In this case, the supply of various data to the robot controller 2 is performed by serial transmission via a communication line. Robot 3
Is composed of a base 3a, a robot arm 3b, and a hand 3c. The configuration of the hand 3c is the same as the configuration of FIG. 12 described above.

Next, FIG. 3 is a block diagram showing a schematic configuration of the computer 1. In this figure, reference numeral 7 denotes a CPU (central processing unit) for controlling each unit of the apparatus, and 8 denotes a CPU 7
Is a ROM (Read Only Memory) in which a program for controlling is written, and 9 is a RAM (Random Access Memory) used in the CPU 7. Where R
The program written in OM8 includes welding bead A
A program for creating various data for the finishing processing (see FIG. 11) is included. Note that the supply of various data can be transferred using a storage medium such as an IC card or a magnetic disk.

Reference numeral 10 denotes an input / output interface for exchanging data between the main body of the computer 1 and the robot controller 2. Reference numeral 11 denotes a keyboard, and 12 denotes a CRT control device for controlling the CRT display device 13. Reference numeral 14 denotes an external storage device such as a hard disk device or a floppy disk device.

Next, a method of creating machining path data for the robot 3 will be described. FIG. 4 is a diagram showing a basic pattern of a spiral path, and shows a basic pattern of a processing path of the grindstone 29 at the time of finishing the welding bead A. In the figure,
R is the radius of a semicircle centered on point O1. P1, P
2 and P3 are points arranged on the same straight line,
A point on a semicircular arc of radius R centered at 1; a point on a semicircular arc of radius r centered at point O2; and a connection point between a semicircle of radius R and a semicircle of radius r. . Therefore, the point O1 and the point O2 are located on the straight line connecting the point P1 and the point P3 at a distance of a radius R and a radius r from the point P3, respectively. Therefore, the distance P is calculated by the following equation. R−r = P Equation

Next, FIG. 5 is a view showing a spiral path, and shows a processing path obtained by repeatedly connecting the above-described spiral path basic pattern.

Next, a method of creating machining path data of the robot 3 will be described with reference to the flowchart of FIG.
First, in step SP1, the operator operates the teaching operation panel of the robot (the keyboard 11 of the computer 1).
, Data representing the start point P1 and data representing the end point Pn are input. Next, the process proceeds to step SP2.

In step SP2, the worker sets the starting point P
A section route selection process for selecting whether to connect 1 and the end point Pn with a straight line or an arc is performed. Next, the process proceeds to step SP3.

In step SP3, the operator inputs data values of any two of the parameters of the radii R, r, and the distance P. Next, the process proceeds to step SP4. In step SP4, the CPU 7 calculates an uninput parameter in step SP3 based on the above equation. Next, the process proceeds to step SP5. In step SP5, the CPU 7 creates machining path data having a spiral path (see FIG. 5) obtained by repeatedly connecting a straight line or an arc from the start point P1 to the end point Pn with a spiral path basic pattern (see FIG. 4). You. Then, the data of the machining path created in step SP5 is temporarily stored in the RAM 9. Next, the process proceeds to step SP6.

In step SP6, step SP
The machining path data of the spiral path created in step 5 is output to the robot controller 2. Next, the process proceeds to step SP7. In step SP7, the CPU 7 determines whether or not to end the processing for creating data of the machining path of the robot. That is, when data creation for all routes is completed, it is determined to be completed. On the other hand, when the same machining path is to be machined again with different radii R, r, and distances P, or when data of another machining path is to be created, it is determined to be NO. In this case, the processing path creation processing returns to step SP1.

The data of the robot machining path created in this way is stored in the robot controller 2. During automatic operation of the robot, each part of the robot (robot arm 3b, robot hand 24, linear motion mechanism 25, motor 26, tool chuck 27, grindstone 29)
) Operate according to the machining path data stored in the robot controller 2.

Instead of inputting the values of the radii R, r and the distance P in step SP3, the size (width and height) and hardness of the weld bead A are input as approximate values. You may do it. In this case, a conversion table created based on empirical rules is stored in advance in the ROM 8 of the computer 1, and by referring to the conversion table, the appropriate values of the radii R, r, and the distance P can be automatically determined. It is good to select it.

In the above-described embodiment, the robot 3 operates in accordance with the machining path data stored in the robot controller 2 in advance. Instead, the machining is performed while calculating the path shown in FIG. 5 in real time. It may be performed.

The processing path data of the robot may be created not by the computer 1 but by the robot controller 2. Alternatively, the processing path data may be created by an external personal computer or workstation, and the result may be transferred to the robot controller 2.

Alternatively, a plurality of machining paths may be created by the computer 1, and the machining may be performed a plurality of times by changing the start point, end point, R, r, and P values for each path. In this case, the finished state can be further improved.

Next, the effects of the above-described embodiment will be described. (1) When the weld bead A cannot be completely removed When the weld bead A before processing shown in FIG. 6A cannot be cut off in the finishing work, the conventional method is shown in FIG. 6B. Thus, a step is formed in the remainder of the weld bead A, but according to the method described in the present embodiment, the remaining portion of the weld bead A becomes smooth as shown in FIG.

(2) When the weld bead A is excessively removed. When the weld bead A before processing shown in FIG. 7A is excessively cut in the finishing work, the work W is dug deep as shown in FIG. 7B according to the conventional method. According to the method described in the present embodiment, the work W need only be dug wide and shallow as shown in FIG.

(3) When the position where the weld bead A is applied does not coincide with the machining path of the grindstone 29 As shown in FIG. 8A, the position of the weld bead A and the grindstone 2
In the case where the center line L of 9 is shifted, according to the conventional method, a step is formed in the remainder of the weld bead A as shown in FIG. According to the method described, the remainder of the weld bead A is smooth and the digging is wide and shallow, as shown in FIG.

(4) When the upper surface of the work W is inclined As shown in FIG. 9A, when the upper surface of the work W is inclined, according to the conventional method, as shown in FIG. As shown in FIG. 8B, the state is the same as that in FIG. 8B described above, but according to the method described in the present embodiment, as shown in FIG. You don't have to.

Next, a modified example of a method of creating data of a machining path of another robot will be described with reference to FIG. When the spiral path is created according to the above-described embodiment, the width of the machining path changes between the right side and the left side of the center line. As a method of unifying the width of the processing path, the following method may be used. First, the grindstone 29 is advanced from the start point P1 in the traveling direction along a circle having a radius R to a point P3 by a circumference of a semicircle. Next, from point P3 to point P2,
Assuming a circumference of a radius R that once returns from the point P3 to the start point P1, each point on the circumference (actually, the robot 3 operates while following a point on a curve) is referred to the point P3. And multiplying the distance measured along the traveling direction by {(2RP) / 2R} to connect the reduced points.

That is, let l be the distance in the traveling direction from the point P3 at the point d on the circumference of the radius R shown in FIG. Here, l ′ is defined by the following equation. l ′ = (2R−P) / 2R × l Expression and a point e at a distance of l ′ from the point P3 in the traveling direction of the grindstone 29 is obtained. By connecting the point sequence thus obtained, an ellipse obtained by reducing a circle having a radius R in the traveling direction of the grindstone 29 at a ratio of {(2RP) / 2R} with respect to the point P3 is obtained. By repeatedly using the curves passing through the points P1, P2, and P3 obtained as described above, a machining path having the same width on the left and right from the center line can be obtained.

[0028]

As described above, according to the present invention, a machining path of a teaching playback type robot is provided.
In data creation method, a first step of determining a segment path by entering the start data and end data, the diameter from one another
Two arcs with different radii, and a second step of inputting any two data of the three data of the difference between the half <br/> diameter of the two arcs, the first Section determined by process
A third step of calculating a path that moves from the start point to the end point while turning spirally based on the path and the data input in the second step. The effect is obtained that it is possible to reduce the indentation to an inconspicuous range.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a machining path creation method of a robot according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a robot teaching device according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a robot system to which a machining path data creation method according to one embodiment of the present invention is applied.

FIG. 4 is a diagram showing a basic pattern of a spiral path created according to an embodiment of the present invention.

FIG. 5 is a diagram showing a spiral path created by one embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a state of the weld bead A and the workpiece W when the weld bead A cannot be completely removed.

FIG. 7 is a cross-sectional view showing a state of a workpiece W when a weld bead A is excessively taken.

FIG. 8 is a cross-sectional view showing the state of the weld bead A and the workpiece W when the position of the weld bead A does not match the machining path of the grindstone 9;

FIG. 9 is a cross-sectional view showing a state of the weld bead A and the work W when the upper surface of the work W is inclined.

FIG. 10 is a diagram showing a spiral path created by another modification of the present invention.

11 is an external view of a weld bead A. FIG.

FIG. 12 is an external view of a finish processing of a weld bead A using a grinder by a conventional robot.

[Explanation of symbols]

A: welding bead, W: workpiece, 3b: robot arm, 24: robot hand, 25: linear motion mechanism, 2
6 ... motor, 27 ... tool chuck, 29a ...
Shaft, 29: Grinding stone, P1 ... Start point, Pn ... End point, R,
r: radius, P: distance.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-107404 (JP, A) JP-A-64-5711 (JP, A) Real-life 1983-134274 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B23K 9/127 B23K 9/12 B23K 37/08 B25J 9/10 B25J 9/22

Claims (1)

(57) [Claims] In the data generating method according to claim 1] teaching playback type robot machining path, the first step and the two arcs of radii having different diameters from each other to determine the interval path by entering the start data and end data , And the two
A second step of inputting any two of the three data of the difference between the radii of the arc, the section path determined in the first step, and the second step
A third step of calculating a path that moves from a start point to an end point while helically turning on the basis of the data input in step (a).