JP2827381B2 - Robot teaching point change device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a robot teaching point changing device, and more particularly, to a device that collectively changes a teaching point of a robot.

[Related Art] In recent years, for example, welding robots have been used for arc welding and the like, and when welding members such as vehicles, as shown in FIG. , The torch angle such as the inclination angle and the advancing angle are set to the most preferable values. For example, as one of the techniques for setting coordinates to an optimum value, a technique for changing a coordinate value in accordance with distortion of a work to be worked has been proposed (see Japanese Patent Application Laid-Open No. 61-250705). .

In addition, when welding the robot, a large number of teaching points such as P (1) to P (n) in FIG. 7 are set by using an offline programming device in order to improve the quality of welding. At this teaching point, welding was performed by adjusting the torch angle.

For example, when the torch angle is changed at the teaching points P (1) to P (n), first, as shown in FIG. 8, a teaching point to be changed is specified (S1), and then the changed rotation axis is set. Specify (S
2) Further, the rotation angle value of each axis is input (S3), and it is checked whether or not the change is OK (S4). If the change is OK, the process of changing the torch angle is executed (S5).

[Problems to be Solved by the Invention] However, the teaching operation of the teaching point performed using the above-mentioned off-line programming device does not always provide a high-quality welding posture in one teaching operation, and therefore, is usually performed several times. There is a problem that the teaching point operation is required, and the teaching operation takes time. Furthermore, in the actual welding operation, if it is desired to correct the torch angle along a predetermined welding line, it is necessary to correct the angles of all the teaching points related to the welding operation, and the operation becomes extremely troublesome. there were.

That is, when the number of teaching points is large, there is a problem that the work time for changing the angle becomes longer, and the work time for confirming that the torch angle is not changed is very long.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a robot teaching point changing device that simplifies an operation of correcting a teaching point and can perform good welding.

Means for Solving the Problems According to the present invention made to achieve the above object, as shown in FIG. 1, an off-line programming device is used for data of a teaching point including a torch angle of a robot M1 for welding. In the robot teaching point changing device changed by M2, the teaching point selecting means M3 for selecting the teaching point to be changed, the torch angle selecting means M4 for selecting the type of the torch angle to be changed, and the torch angle selecting means And a posture transformation matrix creating means M5 for creating a posture transformation matrix based on the torch angle input corresponding to the torch angle. Absolute posture changing means M6 for absolutely changing the posture collectively by replacing with a transformation matrix, or the posture for the selected teaching point The gist of the present invention is a robot teaching point changing device, characterized in that at least one of the relative posture changing means M7, which collectively changes the posture by integrating the transformation matrix into the permutation matrix, includes at least one changing means. Is what you do.

[Operation] As illustrated in FIG. 1, the robot teaching point changing device of the present invention changes the data of the teaching point including the torch angle of the robot M1 performing welding by the offline programming device M2.

Then, the teaching point to be changed is selected by the teaching point selecting means M3, the type of the torch angle to be changed is selected by the torch angle selecting means M4, and further selected by the attitude conversion matrix creating means M5 by the torch angle selecting means. Then, a posture transformation matrix is created based on the torch angle input corresponding to the torch angle.

At the same time, the absolute attitude changing means M6 replaces the attitude matrix, which is the teaching point data of the torch to be actually welded, with the attitude conversion matrix for the selected teaching point, thereby absolutely integrating the attitude. Change. Alternatively, the posture is relatively changed collectively by adding the transformation matrix to the posture transformation matrix for the selected teaching point by the relative posture changing means M7.

In the present invention, at least one of the two change means M6 and M7 may be provided.However, both change means M6 and M7 may be provided so that the posture may be absolutely changed and relatively changed. Good.

Next, a preferred embodiment of the robot teaching point changing device of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a robot teaching point changing device according to one embodiment of the present invention together with the entire system. In FIG. 2, the robot teaching point changing device is incorporated in an offline programming device.

As shown in the figure, the off-line programming device 1 is connected to an industrial welding robot 2, and the welding robot 2 has a fixed base 4 for fixing the welding robot 2.
And a turning base 6 for rotating the welding robot 2, and further include a first arm 8, a second arm 10, a bending shaft 12, a swing shaft 14, a twist shaft 16, a welding torch 18 to be controlled, and the like. .

Further, the robot teaching point changing device includes an electronic control unit (ECU) 20 shown in FIG. 3 for performing control such as changing data at the teaching point, and the ECU 20 includes a well-known CPU 20a and a ROM 20b. , A RAM 20c, a backup RAM 20d, an input / output port 20e, a bus line 20f, and the like.

The ECU 20 performs a matrix operation on the data of the teaching point, stores the result of the operation, changes the data, and the like, and also receives an input from a position sensor 21 or the like that detects the drive position of each drive shaft of the welding robot 2. And welding torch 18
And outputs an output for controlling the drive motor 22 and the like for driving the above.

When welding is actually performed by the welding robot 2, coordinates (x, y, z) of the teaching point are set. Then, by setting the coordinates of the position and the posture, the torch angle such as the advancing angle and the inclination angle can be set. That is, as shown in FIG. 4, when the upper plate 23 and the lower plate 24 are joined by welding, the welding torch 18 is arranged at a predetermined interval (wire extension) from the joining position, and And the advancing angle such as the advancing angle or the receding angle.

Next, control of the welding robot 2 will be described with reference to the flowcharts of FIGS.

First, an outline of the operation of changing the teaching point performed using the offline programming device 1 will be described with reference to FIG.

First, the offline programming device 1 is started (step 100), a teaching point for setting a welding direction and the like is created (step 110), and a registered teaching point is called (step 120). Next, robot shape attribute data such as the shape of each axis of the welding robot 2, the form of operation, and the speed is created (step 130), and the registered robot shape attribute data is called (step 140). Next, batch change of teaching points, which is a characteristic part of the present embodiment, which will be described in detail later, is performed (step 150), and control operation data is output from the offline programming device 1 to the welding robot 2 (step 16).
0) This process is temporarily ended.

Next, a description will be given of a data conversion equation used in the process of batch-changing the teaching point data.

The teaching posture data at the teaching point P (i) of the welding robot 2 is expressed by the following equation.

N _x , _y , _z : Normal vector O _x , _y , _z : Orientation vector A _x , _y , _z : Approach vector X, Y, Z: Position vector The teaching matrix when the value (absolute angle) θ is changed is expressed by the following equation.

In addition, a conversion matrix for rotating the traveling angle by a relative value (relative angle) Δθ is expressed by the following equation.

Therefore, the matrix of the teaching points when rotating the relative angle Δθ is P (i) θ ′ = P (i) * K,
It is expressed by the following equation.

On the other hand, since the inclination is a rotation around, the teaching point matrix when the absolute value (absolute angle) α is changed is expressed by the following equation.

A transformation matrix for rotating the dip by a relative value (relative angle) Δα is represented by the following equation.

Therefore, the teaching point matrix when rotated by the relative angle Δα is represented by the following equation since P (i) α ′ = P (i) * T.

Next, based on FIG. 6, a description will be given of a process of controlling the batch change of the torch angle such as the advancing angle and the inclination angle, which is performed by using the above equations.

First, in step 200, it is determined whether or not the torch angle batch change command has been input. If it is determined that the torch angle batch change command has been input, the process proceeds to step 210. In step 210, the welding robot 2 whose torch angle is to be changed is specified.

In the following step 220, all the teaching points P (1) to P (n) to be changed are designated, and the process proceeds to step 230.

In step 230, it is determined whether the change angle is the advance angle or the inclination angle. If it is determined that the change angle is the advance angle, the process proceeds to step 240.

In this step 240, it is determined whether the advance angle is the absolute angle θ or the relative angle Δθ, and if it is determined that the advance angle is the absolute angle θ, the process proceeds to step 250.

In this step 250, the value of the absolute angle θ is input. In the following step 260, the value of i indicating the order of the position of the teaching point is set to an initial value of 1. In step 270, P is calculated using the above equation. Change (i) to P (i) θ.

Further, in step 280, i is incremented. In step 290, it is determined whether or not i has reached n indicating the end of the teaching point. Here, if it is determined that i is not n, the process returns to step 270 and is the next teaching point (i +
P (i + 1) θ in 1) is calculated. On the other hand, if it is determined that i = n, the process proceeds to step 300.

In this step 300, the data to be changed obtained as described above is adopted, and it is checked whether or not the data can be actually changed. If the data can be changed, the process is temporarily terminated,
If the change should not be made, the process returns to step 200 again.

On the other hand, in the step 240, it is determined that the advance angle is the relative angle Δθ, and in the step 310, the value of the relative angle Δθ is inputted. In the subsequent step 320, the value of i indicating the order of the position of the teaching point is changed. The initial value is set to 1, and in step 320, P (i) is changed to P (i) θ 'using the above equation.

Further, in step 340, i is incremented, and in step 350, it is determined whether or not i has reached n indicating the end of the teaching point. Here, if it is determined that i is not n, the process returns to step 330 and is the next teaching point (i +
P (i + 1) θ in 1) is calculated. On the other hand, if it is determined that i = n, the process proceeds to step 300.

Further, in step 360, where it is determined in step 230 that the change angle is a dip, the process proceeds to step 360, in which it is determined whether the dip is an absolute angle α or a relative angle Δα. .

Hereinafter, the processing of Steps 370 to 410 is the same as the processing of Steps 250 to 290 except for the difference between the absolute angle θ of the advancing angle and the absolute angle α of the dip angle. Since the processing is almost the same, the description is omitted. In step 390, P (i) is changed to P (i) α using the above equation.

On the other hand, if it is determined in step 360 that the inclination is the relative angle Δα, the process proceeds to step 420.

Hereinafter, the processing of Steps 420 to 460 is the same as the processing of Steps 310 to 350 except for the difference between the relative angle Δθ of the advancing angle and the relative angle Δα of the dip, except for the processing of the calculation of Step 440. Since the processing is almost the same, the description is omitted. In this step 440, P (i) is changed to P (i) α 'using the above equation.

As described above, in the present embodiment, the data at each teaching point is changed collectively by using the above-mentioned equations (1) to (3), so that there is an effect that the number of teaching steps can be significantly reduced. Also, by changing the torch angle, if the teaching point cannot be reached while holding the changed torch angle posture, it can be known before the operator actually teaches, so the man-hour can be reduced, and the time and effort required for trial and error is significantly reduced. There is an advantage of doing so.

Furthermore, since there are two kinds of changing methods, an absolute angle and a relative angle, the method can be used properly when the designated angle is fixed or when the angle is finely adjusted, so that efficient work can be performed.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments at all, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. .

[Effects of the Invention] As described in detail above, the robot teaching point changing device of the present invention selects a teaching point to be changed, selects a type of a torch angle to be changed, and is further selected by torch angle selecting means.
A posture transformation matrix is created based on the torch angle input corresponding to the torch angle, and for the selected teaching point, the posture is absolutely batched by replacing the posture matrix with the posture transformation matrix, or Since the posture is changed collectively by adding the transformation matrix to the posture transformation matrix,
The man-hour for teaching data to the robot can be greatly reduced.
Further, based on the data, it is possible to actually check whether or not the data of the teaching point is appropriate. Therefore, there is an effect that the labor for the operator to perform trial and error is reduced.

[Brief description of the drawings]

FIG. 1 is an illustration of the basic configuration of the present invention, FIG. 2 is a system configuration of the embodiment, FIG. 3 is a block diagram showing an electronic control unit, FIG. FIG. 4 (b)
Is an explanatory diagram showing a traveling angle, FIG. 5 is a flowchart showing an outline of a posture teaching method, FIG. 6 is a flowchart showing a detailed control of the posture teaching, FIG. 7 is an explanatory diagram showing a conventional welding method, FIG. FIG. 8 is a flowchart showing a conventional posture teaching method. M1 ... Robot M2 ... Offline programming device M3 ... Teaching point selecting means M4 ... Torch angle selecting means M5 ... Posture conversion matrix creating means M6 ... Absolute posture changing means M7 ... Relative posture changing means 1 ... … Offline programming device 2… Welding robot 18… Welding torch

Continuation of front page (56) References JP-A-62-108314 (JP, A) JP-A-60-261674 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05B 19 / 4093 G05B 19/42 B25J 9/22

Claims (1)

(57) [Claims] 1. A robot teaching point changing device for changing data of a teaching point including a torch angle of a robot performing welding by an off-line programming device, a teaching point selecting means for selecting the teaching point to be changed, and the changing. Torch angle selection means for selecting the type of torch angle, and attitude conversion matrix creation means for creating an attitude conversion matrix based on the torch angle selected by the torch angle selection means and input corresponding to the torch angle And a teaching point selected by the teaching point selecting means.
By replacing the attitude matrix with the attitude conversion matrix, absolute attitude changing means for absolutely changing the attitude in a lump, or for the teaching point selected by the teaching point selecting means, A robot teaching point changing device, comprising: at least one of: a relative posture changing unit that relatively changes the posture collectively by integrating a conversion matrix.