JP2001025870A - Welding robot system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding robot system where a main PC directly controls the traveling route of the welding robot when a welding work is carried out. SOLUTION: In the welding robot system provided with a welding robot 200, a robot controller 203 which drives the welding robot 200, a sensor block 202 which senses the welding condition of the welding robot 200, and a main PC 205 which unifiedely controls the robot 200 and a robot controller 203, the main PC 205 directly controls the traveling route of the welding robot 200 by sending a correction instruction about the traveling route of the welding robot 200 to the robot controller 203 on the basis of a sensing signal supplied from the sensor block 202.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding robot system, and more particularly, to a main PC for overall control of the system, a robot controller for driving and controlling a welding robot, and a sensor unit for sensing information on welding conditions such as a welding path. When,
The present invention relates to a welding robot system including:

[0002]

2. Description of the Related Art In recent years, welding robots have been used at industrial sites to weld various materials such as iron plates.
Welding is performed by spot welding, in which welding is performed with a welding torch fixed so as to weld one point of the welding base material fixed to the jig, and welding is performed while the welding torch moves along the welding path of the welding base material. Arc welding is mainly performed in robot welding.

[0003] Arc welding is a welding method in which a strong current is formed between a welding torch and a base metal to be welded while supplying a wire to instantaneously melt and weld the wire and the base metal. When performing arc welding, the supply voltage, the separation distance between the welding torch and the base material, the wire supply speed, the weaving speed of the welding torch, and Are set in advance and input to the robot controller. In particular, for high quality welding, it is important to accurately track the welding path on the base material and perform welding. For this reason, various movement route tracking algorithms have been developed and commercialized.

FIG. 1 is a block diagram of a conventional welding robot system. As shown, the welding robot system includes a welding robot 100 for performing welding, a laser vision sensor for sensing a distance between a base material (not shown) and a welding torch (not shown), an image of a welding path, and the like. And a robot controller 103 for controlling the motion of the welding robot 100 based on the sensing signal sampled from the sensor unit 102 and correcting an error in the welding path to perform welding along an accurate path.
And a main PC 105 that performs overall control of the welding robot system, such as processing of welding-related data, control of the position setting of the welding robot 100, and control of additional equipment.

[0005] Here, the main PC 105 sends the supply conditions, the separation distance between the welding torch and the base material, the supply speed of the wire, the weaving speed of the welding torch, and other conditions for performing the work, and the command to start the welding work by the robot controller 103. , The robot controller 103 drives the welding robot to perform a welding operation based on this. At this time, the robot controller 103
Samples the various kinds of sensing information on the current welding progress from the sensor unit 102, compares and analyzes the information through various moving path tracking algorithms currently commercialized, and corrects and controls the current moving path of the welding robot. can do.

As described above, in the conventional welding robot system, once the main PC 105 once instructs the robot controller to issue a work start command together with the conditions for performing the welding work, then the welding robot 1 during the welding progress process.
Since the control of the movement route of 00 is performed by the robot controller 103, it is virtually impossible to participate in the control.

Therefore, although the user plays a role of monitoring all of the welding robot system through the main PC 105, by controlling the movement path during the progress of the welding operation, all the control and uniformity of the control of the welding robot system are achieved. It is impossible to improve.

[0008]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a welding robot system capable of controlling a movement path of a welding robot through a main PC during a welding operation.

[0009]

According to the present invention, there is provided a welding robot, a robot controller for driving the welding robot, a sensor unit for sensing a welding state of the welding robot, and the welding robot. In a welding robot system comprising a robot and a main PC for controlling the robot controller, the main PC sends a correction command for a movement path of the welding robot based on a sensing signal from the sensor unit to the robot controller. To directly control the movement path of the welding robot.

Here, the transmission and reception of the correction command between the main PC and the robot controller use any one of serial communication, parallel communication, and network communication. In particular, the serial communication is RS232C communication. Is preferred.

It is preferable that the main PC and the robot controller have a communication interface based on a selected communication method.

[0012] It is effective that the correction command from the main PC is sent at predetermined time intervals at which real-time control is possible.

On the other hand, the robot controller includes the main PC
The main PC has a built-in control program including predetermined communication parameters for communication of the correction command with the robot controller. Is preferred.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 2 is a control block diagram of the welding robot system according to the present invention. As shown, the welding robot system according to the present invention includes a welding robot 200 for performing welding, and a laser vision sensor for sensing a distance between a base material (not shown) and a welding torch (not shown) and a welding path. Sensor 202 and processing of welding-related data, control of position setting of welding robot 200, control of additional equipment for attachment / detachment of a welding base material, etc., general control of a welding robot system, and sampled from sensor 202. A main PC 205 that calculates a correction value of the movement path of the welding robot based on the sensing information and sends a correction command to the robot controller, and a robot controller 203 that corrects the movement path of the welding robot 200 according to the correction command from the main PC. , Is provided.

Here, the main PC 205 and the robot controller 2
The transmission and reception of the correction command to and from the PC 03 are performed by serial communication such as RS-232C and parallel communication or network communication using a run (LAN) mainly used for communication between the I / O device and the PC. Of course, the main P
Each of the C205 and the robot controller 203 must be equipped with a communication port according to the communication type.

Typical protocol for serial communication (protocol)
RS-232C (Recommended Standard No. 232 revision
C) is an interface standard for connection between a computer and a peripheral device such as a modem, determined by the American Electrical Manufacturers' Association. Therefore, the main PC 205 and the robot controller 203 should be equipped with connectors, cables, and communication equipment manufactured in accordance with the RS-232C standard.
Since the -232C communication system is employed, it is usually sufficient to check only that the robot controller 203 is not mounted.

The parallel communication is a communication method typically used for communication between a computer peripheral device such as a printer and a computer main body, and connects a cable to the robot controller 203 using a parallel port supported by the main PC 205. It is executed by providing a corresponding interface.

A run (LAN) is a local area communication network provided to share a large number of computers in a relatively small space and a large-capacity storage device connected thereto. This allows computers connected to an information network to exchange information at high speed by sharing information contained in many computers. In a factory where a welding robot is used, a run is often provided due to the necessity of constructing a control system.
Using this, the main PC 205 can communicate with the robot controller 203.

As described above, the main PC 205 can communicate with the robot controller 203 by adopting one of the above three communication methods.

FIGS. 3A and 3B are schematic views showing the welding process of the welding robot system according to the present invention, and FIG. 4 is a control flowchart of the welding robot in the welding process of FIG. .

Here, the welding robot 200 has a welding start point a for welding an irregular welding path 301 as shown in the figure.
The main PC teaches a straight path 302 connecting the welding end point b and the actual welding path 3 when the welding is actually performed.
The welding is performed by a path tracking method of moving to the actual welding path 301 in response to an error correction command between the instruction 01 and the taught straight path 302. The robot controller 203 is a main PC 205
From the welding base metal, the wire feed speed,
After the start point a of the welding path is taught together with the welding condition variables such as the supply voltage (S1), the welding torch 30
0 is located at the start point a of the welding path (S2), and the welding torch 300 is driven by the robot controller 203 that has received the work disclosure command from the main PC 205, and starts welding work (S3). When welding starts, the laser vision camera 303 attached to the welding torch sends vision information data indicating the current welding state, that is, an error from the actual welding path, etc., to the main PC 205.

The main PC 205 samples welding path error data received from the vision camera 303 (S4).
Based on this, a position error is calculated by a predetermined algorithm, and a position correction command is transmitted to the robot controller 203 (S5). At this time, the transmission of the position correction command is performed by one of the three communication methods described above, that is, one of serial communication, parallel communication, and network communication.

The robot controller 203 controls the motion of the welding torch 300 of the welding robot 200 in accordance with the position correction command from the main PC 205 to track and control the welding path 301 to be actually welded (S).
6).

As described above, the system in which the robot controller 203 controls the welding robot 200 in accordance with the position correction command from the main PC 205 is a 6-axis articulated type used in a large assembly line during ship welding in a shipyard. The present invention can also be applied to a mounting positioner for a robot, a 5-axis positioner, and a 6-axis articulated type robot.

That is, according to the present invention, the control of the servomotor for the operation of the robot manipulator and the positioner is performed by the robot controller, but the control of the motion and other welding sequences, the additional equipment, and the management of the auxiliary data are mainly performed. This is performed by a macro file in the PC.

More specifically, the main PC 205 receives and samples the vision data for the welding path being advanced from the laser vision camera 303 mounted on the end effector of the manipulator of the welding robot 200, and calculates a path error based on the vision data. After that, a correction command is sent to the robot controller 203 at a predetermined interval (approximately 96 msec).

The robot controller 203 reads a correction command from the main PC 205, recognizes a correction position based on the correction command, and sends the correction command to a servo controller of a servo motor that directly drives the welding robot 200 to perform welding. The robot 200 can track an accurate welding path.

The transmission interval of the correction command may vary depending on the system environment of the welding robot. In practice, the 96 msec interval control is a sufficient control interval for controlling the arc welding robot, not for the operation of the fine robot.

The robot controller 203 is provided with a large number of welding parameters, and the user specifies and initializes these parameter values appropriately according to the purpose of use and the environment. The input parameters required for the path control of the main PC-driven welding robot according to the present invention are as follows.

1. COMMUNICATION TYPE (0 = NOT USED,
1 = SERIAL, 2 = PARALLEL, 3 = NETWORK) DATA SAMPLING UNIT (0 = NOT USED, 1 = 96msec, 2
= 192msec, 3 = 384msec) CORRECTION AMOUNT (0.001m Unit: 0 to 1000) 4. DATA ACCEPT FEEDBACK (0 = NOT OK, 1 = OK) 5. POSITION DATA FEEDBACK (0 = NOT OK, 1 = OK) PARALLEL BIT SETTING (BIT, BIT, BIT: LEFT, RIGH
IT, HOLD)

The COMMUNICATION TYPE 1 is a parameter for selecting one of serial, parallel, and network communication systems between the robot controller and the main PC. The robot control is performed according to the communication system selected here. The corresponding path command must be specified in the program. The second DATA SAMPLING UNIT is used to set a time interval for inputting data, and must be appropriately selected according to a welding robot system environment and characteristics of a welding operation. The CRRECTION AMOUNT of No. 3 is required to specify a path correction value, and usually about 150 to 200 at a time is appropriate. Four
DATA ACCEPT FEEDBACK and 5 POSITION DATA FEEDBACK relate to the possibility of adopting the function of correcting the position according to the command from the main PC, receiving the command and informing the main PC of the correction result, and the welding robot system of the main PC. When considering the role of the general control, it is preferable to set both of them to 1 to notify the result of the instruction execution.
The PARALLEL BIT SETTING 6 is a contact selection area for bit mapping for connecting the robot controller and the main PC in hardware when the robot controller and the main PC are connected by parallel communication. For example, 1, 2,
If the number is 10, LEFT is the first contact, RIGHT is 2
The contact No. HOLD means that the contact No. 10 has been selected.

The following is an example in which the robot controller is actually programmed to weld an irregularly curved welding path from one point of a welding base material to another point by a teaching path method.

MOVE # PNT1 MOVE # PNT2 MOVE # PNT3 DELAY 0.5 AS -1,22,150 MOVES / P # PNT4 AE, -1,20,120 MOVE # PNT5 MOVE # PNT6 END

Here, # PNT1, # PNT2, # PNT3, #P
NT4, # PNT5, and # PNT6 are predetermined points on the welding route according to the welding order to be performed, and are values set by the user. MOVE # PNT1 moves the robot, M
OVE # PNT2 moves closer to the welding position, MOVE
# PNT3 means moving the welding start point, DELAY 0.5 has 0.5sec time delay for system stabilization, AS-1,22,15
0 indicates that welding starts at 22V, 150A.

MOVE / P # PNT4 is connected to the main PC by parallel communication.
From the # PNT3 to # PNT4, the welding is performed with a voltage of 22V and a current of 150A, and an external LEF
The movement route is changed by inputting T, RIGHT, and HOLD Bit. Since the change of the movement path is specified by the IO bit set through the input parameter No. 5 described above, according to the above example, when 2 is input, the path corresponding to the amount specified to the right from the reference in the direction of motion of the motion is set. Changes are made. MOVES / S means serial communication, MOVES / NE means network communication, and these communication can be easily realized by respective defined communication protocols. On the other hand, A
E, -1, 20, 120 indicate that welding is over, MOVE #PNT
5 indicates moving to the next position, MOVE # PNT6 indicates moving to a safe position, and END indicates the end of the program.

The above-described input parameters and programs in the robot controller are merely examples, and appropriate adjustments can be made as needed.

[0037]

As described above, according to the present invention, there is provided a welding robot system capable of controlling a movement path of a welding robot through a main PC when a welding operation is performed. Therefore, when conducting research and development on a control program of a movement path of a welding robot in a school, a research institute, or the like, the program can be developed using the welding robot system according to the present invention. It is possible to develop a control program for the travel route.

[Brief description of the drawings]

FIG. 1 is a block diagram of a conventional welding robot system.

FIG. 2 is a control block diagram of the welding robot system according to the present invention.

FIG. 3 is a schematic view showing a welding process of the welding robot system according to the present invention, wherein (a) shows a welding start state,
(B) is a figure which shows the state where welding advanced halfway.

FIG. 4 is a control flowchart of the welding robot in the welding process of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 100 Welding robot 102 Vision sensor part 103 Robot controller 105 Main PC 200 Welding robot 202 Vision sensor part 203 Robot controller 205 Main PC 300 Welding torch 301 Welding path 302 Straight teaching path 303 Vision camera

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[Procedure amendment]

[Submission date] July 3, 2000 (2007.3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

1. A welding robot and driving the welding robot
A robot controller for controlling a sensor unit for sensing the welding condition of the welding robot, Oyo said welding robot
And a main PC that controls the robot controller in a comprehensive manner. The main PC calculates a correction value for the movement path of the welding robot based on a sensing signal from the sensor unit.
As well as out, by sending a correction command for moving path of the welding robot in the robot controller, welding robot system and controlling the movement path of the welding robot in real time. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 6, 2000 (200.11.
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

2. The welding robot system according to claim 1 , wherein the serial communication is RS232C communication.

3. The main PC and the robot controller,
The welding robot system according to claim 1 , further comprising a communication interface according to the selected communication method.

4. A welding robot system according to claim 1 wherein the correction instruction from the main PC is characterized in that it is sent at predetermined time intervals are possible real-time control.

Wherein said robot controller, welding robot system according to claim 1, characterized in that it incorporates a control program including a predetermined communication parameters for transmitting and receiving the correction instruction to the main PC .

Wherein said main PC, claim 1, characterized in that it incorporates a control program including a predetermined communication parameters for communication correction command of the robot controller
The welding robot system according to item 1.

Claims (7)

[Claims] 1. A welding robot, a robot controller for driving the welding robot, a sensor unit for sensing a welding state of the welding robot, and a main PC for controlling the welding robot and the robot controller. In the welding robot system provided, the main PC directly controls the movement path of the welding robot by sending a correction command for the movement path of the welding robot to the robot controller based on a sensing signal from the sensor unit. A welding robot system characterized by the following. 2. The transmission and reception of a correction command between the main PC and the robot controller is performed using any one of serial communication, parallel communication, and network communication. The welding robot system according to item 1. 3. The welding robot system according to claim 2, wherein the serial communication is RS232C communication. 4. The main PC and the robot controller,
The welding robot system according to claim 2, further comprising a communication interface according to the selected communication method. 5. The welding robot system according to claim 1, wherein the correction command from the main PC is sent at predetermined time intervals at which real-time control is possible. 6. The welding robot system according to claim 1, wherein the robot controller has a control program including predetermined communication parameters for transmitting and receiving a correction command to and from the main PC. . 7. The control system according to claim 1, wherein the main PC includes a control program including predetermined communication parameters for communicating a correction command with the robot controller.
The welding robot system according to item 1.