JPH08194519A - Weld line sensing teaching method - Google Patents

Abstract

PURPOSE: To provide a weld line sensing teaching method which can shorten the teaching time. CONSTITUTION: The sensing operations which sense the weld lines W of welded bodies 1 and 2 by a sensor 4 are taught and stored into a welding robot R including the sensor 4 and a torch 5 which are attached to a robot arm 3. In such a constitution of a weld line sensing teaching method, the sensor 4 detrects the coordinate value of edges of both bodies 1 and 2. Then the coordinate difference is calculated between the detected coordinate value and a desired sensing position, and the position of the sensor 4 is shifted by the robot and by an extent equal to the coordinate difference. When the coordinate difference is set within a prescribed allowable range, the position of the sensor 4 is stored in a controller (control part) 6 of the robot R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for teaching a welding robot having a sensor and a torch for sensing a welding line.

[0002]

2. Description of the Related Art Conventionally, automatic welding has been carried out by a welding robot. This welding robot is equipped with a sensor 4 and a torch 5 at the tip of a robot arm 3, as shown in FIG. Are known.

For example, in order to automatically weld the pillar 1 and the beam 2 with the welding robot R, the welding robot R is taught (teach memory) for standard welding operation in advance.

When actually performing automatic welding,
The welding line W between the pillar 1 and the beam 2 is detected by the sensor 4,
The control device (control unit) 6 compares the detected data with the setting data at the time of teaching, corrects the taught standard welding operation, and welds with the torch 5.

As described above, in this type of welding robot R, it is necessary to teach the standard welding operation of the torch 5 and the sensing operation of the sensor 4, and the accuracy of the welding operation (reproducibility of the standard welding operation) is improved. In order to do so, it is required to perform these teachings accurately.

Therefore, conventionally, the following method has been adopted for teaching the sensing operation.

First, as shown in FIG. 2, the laser red emission line from the sensor 4 is irradiated vertically to the side surface of the model of the object to be welded (hereinafter referred to as the "model to be welded") M. , Adjust the orientation of the sensor 4.

Second, the sensor 4 is aligned with the position to be sensed and the position is stored.

That is, the welding robot R is driven while visually confirming that the laser red emission line from the sensor 4 overlaps the sensing reference line (not shown) marked on the model M to be welded.

Next, as shown in FIG. 7, the model body M to be welded is
The monitor receives the sensing waveform reflected from the monitor, and calculates the coordinate value (position) of the edge of the model to be welded M from this sensing waveform. In addition, the point A in FIG. 7 has shown the edge of the to-be-welded model body M.

Then, while observing the coordinate values, the welding robot R is driven so as to move the sensor 4 to a desired (sensing) position, and the position is stored.

Incidentally, as this type, Japanese Patent Laid-Open No. 3-1
The one described in Japanese Patent No. 42069 is known.

[0013]

By the way, in such a conventional welding line sensing teaching method, when the sensing position is stored, the coordinate value of the edge of the welded model M is calculated from the sensing waveform on the monitor. Calculate and check the coordinate values while the operator moves the sensor 4 to the sensing position.
There is a problem that the teaching work requires a long time because the work of moving the robot is performed.

This is a serious problem as the number of sensing positions to be stored increases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a teaching method for welding line sensing which can shorten the teaching time.

[0016]

In order to achieve this object, the invention as set forth in claim 1 provides a welding robot having a sensor and a torch on a robot arm for sensing the welding line of the object to be welded. A teaching method of welding line sensing for teaching and storing a sensing operation for detecting a coordinate value of an edge of the object to be welded by the sensor, and calculating a coordinate difference between the coordinate value and a desired sensing position. Then, the position of the sensor is moved by the coordinate difference by the welding robot, and when the coordinate difference falls within a predetermined allowable range, the position of the sensor is stored in the control unit of the welding robot. And

[0017]

According to the first aspect of the invention, the coordinate difference between the coordinate value of the edge of the object to be welded and the desired sensing position is calculated, and the sensor position is moved based on this coordinate difference. The teaching of the sensing position can be performed automatically regardless of the operator, and the teaching time can be shortened.

Moreover, since the coordinate value is detected by the sensor and the sensor position is moved by the welding robot until the coordinate difference falls within a predetermined allowable range, the sensing position can be taught with high accuracy.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

The same components as those in the conventional example are designated by the same reference numerals.

Reference numeral R in the drawing denotes a welding robot, and a sensor 4 and a torch 5 are provided at the tip of the robot arm 3 of the welding robot R.

Further, the welding robot R has a control device (control unit) 6 for controlling the movement of the robot arm 3, and the control device 6 stores the standard welding operation and the sensing operation which are taught. I'm standing.

Then, for example, as shown in FIG.
In the case of automatically welding the beam 2 and the beam 2, the welding line W between the column 1 and the beam 2 is detected by the sensor 4 based on the sensing operation, and the control device 6 calculates the detected data and the setting data for teaching. By comparison, the standard welding operation that has been taught is modified, and welding is performed using the torch 5.

Next, a teaching method of the sensing operation for detecting the welding line W will be described.

As a first step, as shown in FIG. 2, the laser red light emission line from the sensor 4 is vertically irradiated to the side surface of the model of the object to be welded (hereinafter referred to as "model to be welded") M. Then, adjust the orientation of the sensor 4.

That is, first, as shown in FIG. 3, the angle meters 7 and 8 are attached to the sensor 4 and the model body M to be welded,
At the angle indicated by the goniometer 8 on the model to be welded M, the sensor 4
The robot arm 3 is rotated in the direction of arrow B so that the angles indicated by the above-mentioned goniometer 7 coincide with each other, and the yz of the sensor 4 is changed.
Match the direction.

Next, as shown in FIG. 4B, the laser red emission line L2 irradiated on the side surface of the model body M to be welded is
The robot arm 3 is rotated in the direction of arrow C in FIG. 4A so that it is parallel to the sensing reference line L1 marked on the model to be welded M, and the sensor 4 is aligned in the xz direction.

Finally, as shown in FIG. 5B, the sensing waveform F from the model to be welded M received on the monitor.
However, the robot arm 3 is rotated in the direction of arrow D in FIG.
The y direction is aligned.

In the second step, the sensor 4 is aligned with the position to be sensed and the position is stored in the control device 6 (see FIG. 6).

That is, the welding robot R is driven while visually confirming that the laser red emission line from the sensor 4 overlaps with the sensing reference line marked on the model M to be welded.

Then, a coordinate value transmission command is transmitted from the control device 6 to the sensor 4 (step 11).

The sensor 4 receiving this coordinate value transmission command detects the coordinate value of the edge of the model to be welded M and transmits the detection result to the control device 6 (step 12).

Upon receiving the detection result, the control device 6 calculates the coordinate difference between the detected coordinate value and the preset sensing position (step 13), and the coordinate difference falls within a predetermined allowable range. It is determined whether or not there is (step 14). Here, in this embodiment, the coordinate difference is within an allowable range of 0.1 mm for both the x value and the z value.

If the coordinate difference is outside this allowable range,
The welding robot R is driven so as to move the position of the sensor 4 by the coordinate difference (step 15), and the sensor 4 is turned on again.
A coordinate value transmission command is transmitted to (step 11).

In this way, the coordinate value detection by the sensor 4 and the movement of the sensor 4 by the welding robot R are repeatedly performed until the coordinate difference falls within the allowable range.

On the other hand, if the coordinate difference is within the allowable range, the position of the sensor 4 is stored in the control device 6 (step 16).

Then, it is judged whether or not the teaching process for all sensing positions is completed (step 1
7) If not finished, the sensing position is set to the next sensing position (step 18) and the teaching process is repeated. If finished, the teaching work is finished.

In this way, the coordinate difference between the coordinate value of the edge of the model to be welded M and the desired sensing position is calculated, and the position of the sensor 4 is moved based on this coordinate difference. Instead, the sensing position can be taught automatically and the teaching time can be shortened.

Moreover, since the coordinate value detection by the sensor 4 and the movement of the sensor 4 position by the welding robot R are repeatedly performed until the coordinate difference falls within a predetermined allowable range, the sensing position can be taught with high accuracy. it can.

Although the embodiments of the present invention have been described with reference to the drawings, the specific structure is not limited to the above-mentioned embodiments, and there are design changes and the like within the scope not departing from the gist of the present invention. However, it is included in the present invention.

For example, in the above embodiment, it is judged whether the coordinate difference is within a predetermined allowable range (step 1
4) is carried out before the position movement of the sensor 4 (step 15), but the position movement of the sensor 4 is carried out first, and then it is judged whether it is within the allowable range, If so, the position of the sensor 4 may be stored (step 16), and if not, the process may return to step 11.

[0042]

As described above, according to the first aspect of the invention, the coordinate difference between the coordinate value of the edge of the object to be welded and the desired sensing position is calculated, and based on this coordinate difference. Since the sensor position is moved by the operator, the sensing position can be automatically taught regardless of the operator, and the teaching time can be shortened.

Moreover, since the coordinate value is detected by the sensor and the sensor position is moved by the welding robot until the coordinate difference falls within a predetermined allowable range, the sensing position can be taught with high accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which automatic welding is performed by a welding robot.

FIG. 2 is a perspective view showing a state in which a welding robot is teaching a sensing operation.

FIG. 3 shows the sensor y-
It is a conceptual diagram which shows the state which is adjusting the direction of z direction.

FIG. 4 is a conceptual diagram showing a state in which the orientation of the sensor in the xz direction is adjusted in the same embodiment, (a)
Shows the rotation direction of the robot arm, and (b) shows the laser red emission line irradiated to the model body to be welded.

FIG. 5 is a conceptual diagram showing a state where the sensor is adjusted in the xy direction in the same embodiment, FIG.
Shows the rotation direction of the robot arm, and (b) shows the sensing waveform received by the monitor.

FIG. 6 is a main flowchart of a welding line sensing teaching method in the same embodiment.

FIG. 7 is a monitor screen view showing a sensing waveform reflected from a model to be welded in a teaching method of a conventional example.

[Explanation of symbols]

 1 pillar 2 beam 3 robot arm 4 sensor 5 torch 6 controller (control unit) R welding robot M welded model body

Claims (1)

[Claims] 1. A welding line sensing teaching method for teaching and storing a sensing operation for sensing a welding line of a body to be welded by the sensor in a welding robot having a robot arm having a sensor and a torch. Detects the coordinate value of the edge of the object to be welded, calculates the coordinate difference between this coordinate value and the desired sensing position, and moves the position of the sensor by the coordinate difference by the welding robot; A teaching method for welding line sensing, characterized in that the position of the sensor is stored in a control unit of the welding robot when the difference falls within a predetermined allowable range.