Welding robot

A measured welding event is reproduced by a welding robot. Welding events are organized into a database by a three-dimensional measuring device and a data logging device, and the welding events are subjected to statistical and analytical processes, thereby producing operation data of a robot.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
According to the invention configured as described above, a welding 
operation which is conducted by a person can be registered in the welding 
operation database in the form of digital information, and hence operation 
data of the welding robot can be prepared on the basis of information of 
the welding operation database. In the preparation of operation data of 
the welding robot, information of the welding operation database can be 
processed by statistical and analytical processes, and hence optimum 
operation data for the welding robot can be prepared. 
Since the three-dimensional displaying means is used, information 
accumulated in the welding operation database can be displayed and checked 
in a visual and three-dimensional manner. 
Since an image and a video can be accumulated together with welding 
conditions in the welding operation database, the manner of a welding 
operation, the state of a workpiece, and a result of the welding operation 
can be displayed and checked in a visual manner. 
Since the three-dimensional display using the three-dimensional displaying 
means, and the display and check of the image and the video can be 
simultaneously implemented, these displays can be comparatively checked on 
a display screen in a visual manner. 
Since welding conditions can be captured via the data logging device during 
playback of operation data for the welding robot, the conditions can be 
checked with being compared with information stored in the welding 
operation database. 
Since the welding operation database is stored in the form of digital 
information, welding conditions which are usually managed in a personal 
manner can be transmitted to the next generation. 
Hereinafter, an embodiment of the invention will be described with 
reference to the accompanying drawings. 
FIG. 1 is a schematic view showing a welding robot according to an 
embodiment of the invention. The welding robot according to this 
embodiment comprises: a welder 1 which is used by a person to conduct a 
welding process; a three-dimensional measuring device 2 which measures a 
welding operation; data logging devices 3 and 15 which measure input and 
output currents/voltages of welders, respectively; a camera 4 which 
records a welding scene and a welding result in the form of an image; a 
video camera 5 which records a welding scene and an arc state in the form 
of a video; a robot 13 which reproduces a welding operation; a welder 14 
which is used by the robot to conduct a welding process; torch path 
collecting means 6 for collecting the position and attitude of a welding 
torch from the three-dimensional measuring device 2; current/voltage 
collecting means 7 for collecting the input and output currents/voltages 
of the welders from the data logging devices 3 and 15; image capturing 
means 8 for capturing an image from the camera 4; video capturing means 9 
for capturing a video from the video camera 5; three-dimensional 
displaying means 10 for three-dimensionally displaying data in a database 
on a display screen of a data management computer 16; analytical and 
statistical processing means 11 for performing an analytical process and a 
statistical process on data in the database; and robot operation 
generating means 12 for generating an operation of the robot on the basis 
of collected data of the welding operation database. 
In the embodiment, the data management computer 16 captures data of the 
welders 1 and 14 via the data logging devices 3 and 15. When welders 
having a digital I/F are used, the computer can capture data without using 
such data logging device or directly from the welders. 
The torch path collecting means 6 and the current/voltage collecting means 
7 collect the torch path and the current/voltage of the welding operation 
which is conducted by the operator with using the welder 1, respectively. 
The collected data are registered to be stored in the database. 
FIG. 2 shows the contents of processes in the torch path collecting means 
6. First, in a reference position measuring process 101, predetermined 
points 202 to 204 on a workbench 201 shown in FIG. 3 are measured, and 
reference coordinates 205 for a welding work are determined. In the 
collection of the torch path, the collection process is performed while 
recognizing the XY plane of the measured reference position coordinates 
205 as the horizontal plane of the real world. Therefore, the workbench 
201 must be provided with an adjusting mechanism which can maintain the 
workbench to be horizontal. 
When the three-dimensional measuring device can be placed so as to be 
horizontal in the real world, it is not required to provide the workbench 
201 with an adjusting mechanism which can maintain the workbench to be 
horizontal. 
Next, in a weld line measuring process 102, the start point 206 and the end 
point 207 of a weld line of a welding object shown in FIG. 3 are measured, 
and weld line coordinates 208 serving as a reference of the collection of 
the torch path are determined. The coordinate system of the weld line 
coordinates 208 is identical with that of the reference coordinates 205, 
and uses the welding start point 206 as the original. 
According to this configuration, the collected torch path can be always 
converted into data with respect to the original. In processes of the data 
collection, such as the three-dimensional display, and the analytical and 
statistical processes, the data of the torch path can be easily handled. 
In a torch path collecting process 103, the torch path of the welding 
operation is collected, and the position and attitude of the torch which 
are expressed in the weld line coordinates 208 are stored. 
When the torch path collecting process 103 is repeatedly implemented, the 
collection can be performed also on a multi-layer welding operation. 
The three-dimensional displaying means 10 enables the path data and 
current/voltage data which are registered and stored in the database, to 
be visually checked on the display screen of the data management computer 
16. 
FIG. 4 shows an image of the three-dimensional display. The torch path of 
the three-dimensional display shown on the display screen of the data 
management computer 16 can be expanded, reduced, or rotated and checked in 
any direction. 
The analytical and statistical processing means 11 performs numerical 
processes, so that the welding event can be digitally analyzed. 
The robot operation generating means 12 can convert the torch path and the 
current/voltage data into an operation of the rot-hot, thereby enabling 
the welding operation to be reproduced. 
During reproduction of the welding operation conducted by the robot, the 
current/voltage collecting means 7 can measure and collect the input and 
output currents/voltages of the welder 14 and the collected data can be 
compared with the contents of the welding operation database. 
The image capturing means 8 captures image data from the camera into the 
data management computer. 
The captured image can be used for checking the situation of the welding 
workpiece, the welding scene, a result of the welding, etc. 
The image capturing means 8 may be realized by, for example, a function 
which is incorporated in a utility of a digital camera or a graphic 
software to read an image from a scanner. 
The video capturing means 9 captures video data from the video camera into 
the data management computer. 
The captured video is temporally synchronized with the three-dimensional 
display of the path data and the current/voltage data, so that the video 
can be used in analyzation of relationships between the welding operation 
and the arc state. 
The video capturing means 9 may be realized by a function of, for example, 
a utility of a digital video camera which is used for connecting the 
camera to a computer, or that of a video captured board. 
As was described above, according to the invention, a person who cannot 
prepare operation data by directly operating a welding robot is enabled to 
prepare operation data of the welding robot by conducting a welding 
operation. 
Furthermore, welding events which are hardly analyzed in a clear manner in 
the prior art can be organized into a database, so that a welding 
operation can be analyzed visually and numerically. 
As a result, when digitized welding events are analyzed in detail and the 
reproduction of a welding operation by the robot is repeated, an welding 
operation conducted by a person skilled in welding can be subjected to 
analysis or the like. 
Moreover, welding conditions which tend to be handled as personal know-hows 
can be organized into a database, and hence the invention is useful also 
in solving the problem in that the number of persons skilled in welding is 
being reduced.