KR20010003879A - Welding robot system - Google Patents

Abstract

PURPOSE: A welding robot system is provided to control a movement path of a welding robot via a higher rank PC. CONSTITUTION: A welding robot(200) performs welding. The distance between a material and a welding torch and a welding path is sensed by a sensor unit(202) with a laser vision sensor. A higher rank PC(205) performs data processing, controlling position of the welding robot and auxiliaries for loading/unloading of parent material for welding, and transmission of a correction command to a robot controller(203). The movement path of the welding robot is corrected by the robot controller according to the correction command transmitted from the higher rank PC.

Description

Welding robot system

The present invention relates to a welding robot system, and more particularly, includes a higher level PC for overall control of a system, a robot controller for driving control of a welding robot, and a sensor unit for sensing information on welding conditions such as a welding path. The present invention relates to a welding robot system.

Recently, a welding robot is used to weld various materials such as steel sheets in an industrial field. Welding is roughly divided into spot welding in which a welding torch is fixed for welding a point of a welding base material fixed to a jig, and arc welding performed by moving the welding torch along the welding path of the welding base material. Arc welding is mainly performed by welding.

Arc welding is a welding method in which a strong current is formed between a welding torch and a base material to be welded while supplying a wire to melt the wire and the base material instantaneously. When arc welding is performed, the robot can be set in advance by supply voltage, separation distance between welding torch and base material, feeding speed of wire, weaving speed of welding torch, welding start point and end point on welding path in advance. It is input to the controller. In particular, for high quality welding, it is important to accurately track the welding path on the base material and perform welding, and various movement tracking algorithms for this purpose have been developed and come out as products.

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 an image of a welding path, a distance between a base material (not shown) and a welding torch (not shown), and a welding path. The robot controller for performing welding along the correct path by correcting the error of the welding path through the motion control of the welding robot 100 based on the sensing signal sampled from the sensor 102 and the sensor 102. And an upper PC 105 which collectively controls the welding robot system such as welding related data processing, positioner control of the welding robot 100, and control of additional equipment.

Here, when the upper PC 105 transmits the work execution conditions such as the supply voltage, the separation distance between the welding torch and the base material, the supply speed of the wire, and the weaving speed of the welding torch to the robot controller 103, The robot controller 103 drives the welding robot to perform a welding operation. At this time, the robot controller 103 samples various sensing information of the current welding progress situation from the sensor unit 102 and compares and analyzes the current welding robot through various motion tracking algorithms currently commercialized. Modify and control the movement route.

As described above, in the conventional welding robot system, once the upper PC 105 instructs the robot controller to start the operation together with the conditions for the welding operation, the movement path control of the welding robot 100 is performed during the welding process. Since it is made by the robot controller 103 is involved in this is virtually impossible.

Therefore, although the user plays the role of monitoring the entire welding robot system through the upper PC 105, it is impossible to improve the uniformity and suitability of the overall control of the welding robot system through the movement path control during the welding operation.

Therefore, an object of the present invention is to provide a welding robot system that can control the movement path of the welding robot through the upper PC during the welding operation.

1 is a block diagram of a conventional welding robot system,

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

3-a and 3-b are schematic views showing the welding process of the welding robot system according to the present invention;

4 is a control flowchart of a welding robot according to the welding process of FIG. 3.

* Explanation of symbols for the main parts of the drawings

100,200: welding robot 102,202: vision sensor

103,203: Robot controller 105,205: Upper PC

300: welding torch 303: vision camera

301: welding path 302: straight teaching path

According to the present invention, a welding robot, a robot controller for driving the welding robot, a welding unit including a sensor unit for sensing the welding state of the welding robot and the upper robot for the overall control of the welding robot, the robot controller In the robot system, the host PC directly controls the movement path of the welding robot by transmitting a correction command for the movement path of the welding robot to the robot controller based on the sensing signal from the sensor unit. It is achieved by welding robot system.

Here, the transmission and reception of the correction command between the host PC and the robot controller uses any one of serial communication, parallel communication, and network communication, and in particular, the serial communication is preferably RS232C communication.

In addition, the host PC and the robot controller is preferably provided with a communication interface according to the selected communication method.

In addition, it is effective that the correction command from the upper level PC is issued at predetermined time intervals capable of real time control.

On the other hand, the robot controller has a built-in control program including a predetermined communication parameter for transmitting and receiving a correction command with the upper PC, the upper PC includes a control program including a predetermined communication parameter for communication with the robot controller. It is preferable that it is built.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a control block diagram of a 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 the distance and the welding path between the base material (not shown) and the welding torch (not shown). The overall control of the welding robot system and the sampled from the sensor unit 202, such as sensor unit 202, welding-related data processing, positioner control of the welding robot 200, control of additional equipment for detachment of the welding base material, etc. Compensating the movement path of the welding robot 200 according to the upper PC 205 for transmitting a correction command to the robot controller by calculating a correction value of the movement path of the welding robot based on the sensing information, and the correction command received from the upper PC. Robot controller 203 is included.

Here, the correction command transmission and reception between the upper PC 205 and the robot controller 203 is performed by serial communication such as RS-232C, parallel communication mainly used for communication between the I / O device and the PC, or by network communication using a LAN. You lose. Of course, in order to communicate as described above, the upper PC 205 and the robot controller 203 should be equipped with a communication port corresponding to each communication type.

RS-232C (Recommended Standard No. 232 revision C), a representative protocol of serial communication, has been widely used as an industry standard as an interface standard for connecting peripheral devices such as computers and modems. Therefore, the upper PC 205 and the robot controller 203 should be equipped with a connector, a cable, and communication equipment manufactured according to the RS-232C standard. Since most PCs adopt the RS-232C communication method, it is usually It is sufficient to check only whether the robot controller 203 is mounted.

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 upper PC 205, and has a corresponding interface. Is executed.

Local Area Network (LAN) is a local area network set up to share a large number of computers in a relatively small space with a large storage device connected to it. Computers connected to the information network by sharing information can be exchanged at high speed. In a factory where a welding robot is used, a LAN is often installed due to the necessity of constructing a system for control, and thus, the upper PC 205 may communicate with the robot controller 203 by using the LAN.

As such, the upper PC 205 may communicate with the robot controller 203 by employing any one of the three communication methods.

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

Here, the welding robot 200 teaches a straight path 302 connecting the welding start point (a) and the welding end point (b) from the upper PC (205) to weld the irregular welding path (301) as shown ( and a path tracking method of receiving the error correction command between the path 301 to be actually welded and the straight path 302 taught while the actual welding is performed, and moving to the actual welding path 301. Welding will be performed. The robot controller 203 receives the starting point (a) of the welding path from the upper PC 205 together with the welding condition variables such as the distance from the welding base material, the wire supply speed, the supply voltage, and the like (S1). Place the 300 at the start point (a) of the welding path (S2), the welding torch 300 is driven by the robot controller 203 received the start operation command from the host PC (205) to start the welding operation (S3). When the welding is started, the laser vision camera 303 mounted on the welding torch 300 transmits vision information data indicating a current welding state, that is, an error with an actual welding path, to the host PC 205.

The host PC 205 samples the welding path error data received from the vision camera 303 (S4), performs a position error calculation according to a predetermined algorithm based on this, and transmits a position correction command to the robot controller 203. (S5). At this time, the position correction command transmission is by one of the three communication methods described above, namely, serial communication, parallel communication and network communication.

The robot controller 203 tracks and controls the welding path 301 to be actually welded by motion control of the welding torch 300 of the welding robot 200 according to the position correction command received from the upper PC 205 (S6). ).

As described above, the robot controller 203 receives the position correction command from the upper PC 205 to control the welding robot 200, the six-axis articule used in the contrasting line of the ship welding in the shipyard It can also be applied to articulated type robots, 5-axis positioners, and 6-axis articulated type robotic positioners.

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

More specifically, the upper PC 205 receives and samples the vision data about the welding path in progress 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 thereon. The robot controller 203 transmits a correction command at a predetermined interval (approximately 96 msec).

The robot controller 203 reads the correction command transmitted from the upper PC 205, generates a correction position based on this, and sends it to the servo controller of the servo motor which directly drives the welding robot 200. Be sure to track this exact weld path.

The transmission interval of correction command can be changed according to the welding robot system environment. In fact, 96msec interval control is sufficient control interval for arc welding robot control, not micro robot operation.

A plurality of welding parameters are set in the robot controller 203, and the user specifies and initializes these parameter values according to the purpose of use and environment. Input parameters required for the upper PC driven welding robot path control 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)

3. CORRECTION AMOUNT (0.001m Unit: 0∼1000)

4.DATA ACCEPT FEEDBACK (0 = NOT OK, 1 = OK)

5.POSITION DATA FEEDBACK (0 = NOT OK, 1 = OK)

6.PARALLEL BIT SETTING (BIT, BIT, BIT: LEFT, RIGHT, HOLD)

1llllj

COMMUNICATION TYPE of ldkfd la1 is a parameter to select one of serial, parallel and network communication between the robot controller and the host PC. Also, the corresponding motion option command should be commanded. DATA SAMPLING UNIT of 2 is for setting data input time interval and should be appropriately selected according to welding robot system environment and welding operation characteristics. The CORRECTION AMOUNT of 3 is necessary for specifying the path correction value, and usually about 150 ~ 200 is appropriate once. DATA ACCEPT FEEDBACK of 4 and POSITION DATA FEEDBACK of 5 relate to the function adoption that informs the host PC of command reception and correction result after performing position correction according to the command from the host PC. Considering the role, it is desirable to set both to 1 to inform the result of command execution. PARALLEL BIT SETTING of 6 is a contact selection area for bit mapping for connecting the robot controller and the upper PC in hardware when parallel communication is performed between the robot controller and the upper PC. In this case, LEFT means contact point 1, RIGHT means contact point 2, and HOLD means contact point 10 is selected.

The following is an example programmed in an actual robot controller to weld an irregularly curved welding path from one point to another of the base material according to the teach 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, # PNT4, # PNT5, and # PNT6 are values set by the user as predetermined points on the welding path according to the welding order to be performed. MOVE # PNT1 means robot movement, MOVE # PNT2 means welding position movement, MOVE # PNT3 means welding start point movement, DELAY 0.5 means 0.5sec time delay for system stabilization, AS -1, 22,150 indicates the start of welding at 22V, 150A.

MOVES / P # PNT4 receives the upper IO input through parallel communication in real time, and the movement path is changed. During the movement from # PNT3 to # PNT4, welding is performed with 22V voltage and 150A current. At the same time, the movement path is changed through LEFT, RIGHT, HOLD Bit input from outside. Since the movement path change is specified through the IO bit set through the input parameter No. 5 described above, according to the above example, when 2 is inputted, the path change amount is changed to the right side based on the current motion progress direction. MOVES / S means serial communication and MOVES / NE means network communication, and these communication can be simply implemented based on a defined communication protocol. On the other hand, AE, -1,20,120 indicates the end of welding, MOVE # PNT5 indicates the movement to the next position, MOVE # PNT6 indicates the movement to the safe position, END means the end of the program.

The above-described input parameters and programs in the robot controller are examples, and appropriate additions and subtractions can be made as necessary.

As described above, according to the present invention, there is provided a welding robot system that can control the movement path of the welding robot through the upper PC during the welding operation.

Therefore, when the research and development of the welding robot movement path control program is to be carried out in a school, a laboratory, etc., it is possible to perform a program development work using the welding robot system according to the present invention. Can develop.

Claims (7)

In a welding robot system comprising 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 higher level PC for controlling the welding robot and the robot controller collectively, The host PC directly controls the movement path of the welding robot by transmitting a correction command for the movement path of the welding robot to the robot controller based on the sensing signal from the sensor unit. The method of claim 1, Welding robot system, characterized in that the transmission and reception of the correction command between the host PC and the robot controller using any one of serial communication, parallel communication, and network communication. The method of claim 2, The serial communication is a welding robot system, characterized in that the RS232C communication. The method of claim 2, And the host PC and the robot controller are provided with a communication interface according to a selected communication method. The method of claim 1, Welding robot system, characterized in that the correction command from the upper PC is sent out at a predetermined time interval capable of real-time control. The method of claim 1, The robot controller is a welding robot system, characterized in that the built-in control program including a predetermined communication parameter for transmitting and receiving the correction command with the host PC. The method of claim 1, The host PC includes a control program including a control program including a predetermined communication parameter for communication of a correction command with the robot controller.