JP2587604B2 - Control device for welding robot - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a welding robot, and more particularly to a welding robot control apparatus suitable for preventing a decrease in welding quality due to an automatic recovery process when a welding abnormality occurs. About. 2. Description of the Related Art In a conventional welding robot, when the robot is stopped due to an abnormal occurrence (alarm) such as welding of a wire or breaking of an arc during a welding operation, an operator marks a relevant portion of a work and then performs an operation. Was instructed to continue. [0003] Recently, there is a welding robot provided with a function for automatically recovering a welding abnormality in order to improve the operation rate. In this case, a recovery processing is automatically performed when a welding abnormality occurs, and the operation rate is reduced. At the same time, the number of occurrences of welding abnormalities is counted. [0004] The prior art described above mainly focuses on the prevention of a reduction in the operating rate due to the automatic recovery process for welding abnormalities, and the prevention of a decrease in welding quality due to the automatic recovery process when a welding error occurs. Not much attention has been paid. An object of the present invention is to provide a control apparatus for a welding robot capable of simplifying automatic / manual determination of welding quality in a subsequent process by totalizing and storing the contents of welding anomalies occurring in a time series. It is in. An object of the present invention is to provide a function of controlling a welding robot having a function of detecting a welding abnormality such as welding of a wire or breaking of an arc, and a function of counting and recording welding abnormality data during operation. In the control device of the added welding robot, prepare a welding abnormality data table that records in time series the contents of the cause and location of the occurrence of the welding abnormality data, and fetch desired data every time a welding abnormality occurs. This is achieved by sequentially storing the data in the data table and displaying the data separately according to the request. In the control device of the welding robot, when a welding abnormality occurs during the operation, the robot stops and the welding machine sends a factor for generating welding abnormality data such as wire welding or broken arc. The desired contents, such as the program (work) number and step number of the work currently being executed, the coordinates of the location of the error, and the time of the occurrence of the abnormal data, along with the cause of the abnormal data, match the welding error data in time series according to the size of the data table. The information is stored in a table and output and displayed as required, so that it can be used for determination of welding quality in a subsequent process. At this time, the occurrence of one welding abnormality causes the address pointer of the welding abnormality data table to be increased by one to indicate the next address. Since there may be a defect, the size of the welding abnormality data table is limited to storing, for example, 100 pieces of data, and the address pointer is increased from 0 to 99 one by one so that the processing becomes zero. It can be a suitable size,
It is practical. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a control device for a welding robot according to the present invention will be described in detail with reference to the illustrated embodiment. First, FIG. 2 shows an embodiment in which a robot control device according to the present invention is applied to a standard welding robot. In FIG.
Is a teaching pendant, 3 is a welding machine, 4 is an output device, 5 is a visual device, and 10 is a robot. A teaching pendant 2, a robot 10, and a welding machine 3 are always installed in the robot control device 1. The output device 4 and the visual device 5 are appropriately installed according to required functions. Output device 4
Corresponds to a TV monitor, a printer, or a host computer connected to a serial line. In the configuration shown in FIG. 2, the robot 10 is guided to a predetermined position by the teaching pendant 2 connected to the robot controller 1, and a series of operation data together with various conditions such as welding information is taught and then the playback is performed. When the welding operation by the welding machine 3 is started, a welding abnormality may actually occur due to a number of failure factors such as a failure in teaching contents and a failure in a work. There are several factors such as welding of a wire, breaking of an arc, running out of cooling water, and the like as factors that cause welding abnormality in these actual welding operations. When an abnormality occurs, data representing these factors is transmitted to the welding machine 3. Is transferred to the robot control device 1 via the PC, and necessary processing is appropriately performed. Conventionally, generally, the robot 10 is stopped, and the occurrence of a welding abnormality is notified to an operator to perform a release process. However, in this method, as described above, a worker must intervene every time a welding abnormality occurs,
This was far from automation. Therefore, recently, as described above, a welding robot equipped with an automatic return function at the time of occurrence of a welding abnormality is being adopted, and according to a welding robot having this type of automatic return function, a wire is used. Automatic release by automatic release of welding, retry of arc break, and the like works, so that the welding operation can be continued without the intervention of an operator, and there is an advantage that a reduction in the operation rate can be minimized. [0015] However, in this method, since it is automatically restored, there is a problem in quality judgment, for example, a welding abnormal portion cannot be clearly identified. Therefore, in the present invention, a welding abnormality data table is newly set in the robot controller 1, and necessary abnormality data is stored in this table every time a welding abnormality occurs. FIG. 1 is a table configuration diagram of a welding abnormality data table provided in the robot controller 1 of FIG. 2, and in the figure, reference numeral 6 denotes a welding abnormality data table. In FIG. 1, the contents stored in the welding abnormality data table 6 for each welding abnormality are enlarged and shown.
As shown in the figure, the cause code, occurrence time, program (work) number, point (step) number, and occurrence position
(Coordinates). As described above, there are several factors of these welding abnormalities, and various factors are stored in the welding abnormality data table 6 as codes in the robot controller 1. Examples of the correspondence between the cause code and the cause type are, for example, code 0 is a stop during welding, code 1 is a wire welded, code 2 is an arc cut, code 3 is a torch contact, code 4 is a cooling water cut, The cord 5 has a low gas pressure, the cord 6 has a broken wire, and the cord 7 has other factors. These factor codes and their contents are configured so that the user can arbitrarily add, delete, or change them and set them. Next, FIG. 3 is a flow chart showing a process of storing the data in the welding abnormality data table 6 by the robot controller 1, in which a factor code process is performed in a process 100, an occurrence time process is performed in a process 101, and a process 102 is performed in a process 102. The program (work) number is stored, the point (step) number is stored in process 103, and the occurrence position (coordinate) is stored in process 104. In step 105, it is determined whether the address pointer AP is maximum (AP = 99).
Then, the address pointer AP is updated (AP = AP + 1), and if it is the maximum, the address pointer AP is initialized in processing 107 (AP = 0). The information stored in the welding abnormality data table 6 can be picked and selected according to the system configuration of the welding robot and the scale of the welding abnormality data table 6. At the beginning of the process, a process for determining whether or not to perform the storage process is added, so that the system designer or the user can freely set these flags. At this time, the welding abnormality data table 6
The larger the size is, the better it is not. The fact that the frequency of occurrence of welding abnormality is high implies that there is a problem with the teaching contents of the robot 10 or one of the welding machine 3 and the work, and an appropriate size is set. Is preferred. Therefore, in this embodiment, a chain-like data table 6 is prepared by preparing 100 pieces of welding abnormality information and initializing only the address pointer when the address pointer AP becomes maximum. Forming
The latest 100 abnormal welding contents can always be stored. Note that the size of the table 6 can also be set arbitrarily by the user within a range that can be set in the memory. FIGS. 4 and 5 show display examples when the contents of the welding abnormality data table 6 of FIG. 1 are displayed on the output device 4 of FIG. 2, respectively. This is an example in which the contents of welding abnormal data are displayed in chronological order for all data, and the display contents at this time are code numbers and their causes, time and program numbers (work names), point numbers,
In addition, values of coordinates X, Y, and Z indicating the position where the abnormality has occurred are shown. When there is a designation that display is unnecessary, the display content is omitted. Therefore, when the output device 4 is a host computer connected via a communication line, the welding abnormality occurrence positions (coordinates) X, Y, and Z in the display contents of FIG.
It can also be used as information such as showing a workpiece shape on a graphic terminal or showing a position (coordinate) where a welding abnormality has occurred. Next, FIG. 5 shows an example in which the contents of the welding abnormality data are similarly edited and displayed for each occurrence factor, and the displayed contents are a code number for each factor such as wire welding, arc break, and torch contact. Program number (work name), point number, etc. In the display example of FIG. 5, if an abnormality occurs at the same point of the same work as shown in the section of wire welding, the teaching data or the display data which can easily determine a defect of the work can be determined. It becomes possible to know the history of the abnormality. It is also apparent that if the robot control device 1 has a function of displaying the workpiece shape and the operating position of the robot 10, the position where the welding abnormality has occurred can be simply illustrated in accordance with the function. Furthermore, if there is a process such as automatic determination of welding quality by the visual device 5 in a subsequent process, the data of the welding abnormality occurrence position can be effectively used as position information therefor. According to the present invention, the causes of the occurrence of welding abnormalities can be seen in chronological order, and if necessary, the program number (work name) and point number at the time of occurrence of the abnormality can be easily seen. Therefore, it is easy to judge the welding quality,
Since the abnormal welding position (coordinates) can be stored, it can be used for graphic display of the location of occurrence and automation of quality judgment by a visual device, and a great effect can be expected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a welding abnormality data table in an embodiment of a control device for a welding robot according to the present invention. FIG. 2 is a system configuration diagram of a welding robot to which the robot control device according to the present invention is applied. FIG. 3 is a flowchart for explaining the operation of the embodiment of the present invention. FIG. 4 is an explanatory diagram showing an example of data display according to an embodiment of the present invention. FIG. 5 is an explanatory diagram showing another example of data display in the embodiment of the present invention. [Description of Signs] 1 Robot control device 2 Teaching pendant 3 Welding machine 4 Output device 5 Visual device 6 Welding abnormality data table 10 Robot

Claims (1)

(57) [Claims] Each time a welding abnormality is detected in a welding robot controller equipped with means for detecting welding abnormalities such as wire welding and broken arcs and means for summarizing and recording welding abnormality data, the welding abnormality at that time is detected. A control device for a welding robot, comprising: a welding abnormality data table for recording occurrence factors in chronological order; and displaying abnormality data for each factor as needed. 2. Each time a welding abnormality is detected in a welding robot controller equipped with means for detecting welding abnormalities such as wire welding and broken arcs and means for summarizing and recording welding abnormality data, the welding abnormality at that time is detected. A control device for a welding robot, comprising a welding abnormality data table for recording occurrence positions in a time-series manner, and displaying abnormality data by position as necessary.