JP2011067895A - Fine adjustment method of robot tool position, and robot control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine adjustment method of a robot tool position and a robot control system by which the operation sequence during fine adjustment of a teaching position is decreased, thereby reducing teaching time; and the only operation of a rotation operation means permits movement along a coordinate axis in a predetermined movement direction of a predetermined movement coordinate system, thereby making it easier to perform teaching during the position fine adjustment. <P>SOLUTION: A rotation operation member 13 is assigned as a fine adjustment operation means of the position of a welding torch T by an enter key 11a. When the rotation operation member 13 is operated, a rotation amount and a rotation direction of the rotation operation member 13 are detected by a rotary encoder 14, and the rotation amount and the rotation direction are notified to a controller 20. A CPU 21 of the controller 20 performs the position fine adjustment of the welding torch T by controlling the movement of the robot R by a predetermined inching amount for each unit of the rotation amount, and along Z-axis of a predetermined tool coordinate system correspondingly to the rotation direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for finely adjusting a position of a tool of a robot and a robot control system.

  Conventionally, when the teaching position of the tool tip provided in the end effector of the robot is finely adjusted, it is performed by operating a keyboard provided in the teaching device. Specifically, the procedure is as follows.

  The operator of the teaching device operates the manual speed selection key on the keyboard to first set the manual speed to the inching speed (for example, inching speed), and then operates the coordinate system selection key on the keyboard. The coordinate system is set to the tool coordinate system, and thereafter the operator uses Z-axis operation keys (including two types of Z-axis plus direction operation keys and Z-axis minus direction operation keys) on the keyboard provided in the teaching device. By pushing, the position of the tip of the tool is adjusted.

  Patent Document 1 proposes a technique in which a teaching device is provided with a jog dial. In Patent Document 1, when this jog dial is rotated, an operation key for designating one of the operation coordinates of the robot arm is used at the same time. The teaching position of the tool tip can be finely adjusted according to the rotation direction of the jog dial and the amount of rotation along the operation coordinates designated by the operation key.

JP 2001-269883 A

  However, when performing fine adjustment of the teaching position of the tip of the torch as described above, with the conventional key operation, it is necessary to change the manual speed of the robot and switch the setting of the coordinate system, and it is necessary to perform a plurality of steps. It was. If the setting is wrong here, the tip of the torch operates with an unintended movement amount, and there is a risk of performing an operation in a different coordinate system. In addition, it is necessary to switch the operation key in the plus / minus direction of the movement target axis, and when performing fine adjustment, it is necessary to frequently move the finger to the adjacent key, which is troublesome.

  In Patent Document 1, when the jog dial is rotated, an operation key for specifying one of the operation coordinates of the robot arm is simultaneously pressed and used. There is a problem that the operation becomes troublesome.

  It is an object of the present invention to eliminate the need for two steps of the step of setting the robot movement speed to the inching speed and the step of setting the tool coordinate system to the movement coordinate system, and operating procedures for fine adjustment of the teaching position. It is possible to reduce the teaching time, and in the case of fine adjustment of the position, it is possible to set the coordinate axis in the predetermined traveling direction of the predetermined motion coordinate system only by the operation of the rotation operation means. An object of the present invention is to provide a method for finely adjusting a position of a robot tool and a robot control system that can be moved along the position and can be easily taught at the time of fine adjustment of the position.

  In order to solve the above-mentioned problems, the invention according to claim 1 is directed to the position of the tool provided on the end effector of the robot by the rotation operating means provided in the teaching device by the assigning means provided in the teaching device. As the fine adjustment operation means, when the rotation operation means is operated, the rotation amount and rotation direction of the rotation operation means are detected by the detection means, and the rotation amount and rotation direction are notified to the controller. And a control means provided in the controller, for each unit of the notified rotation amount, in a predetermined motion amount and in a predetermined motion coordinate system corresponding to the rotation direction. The gist of the fine adjustment method of the tool position of the robot is characterized by finely adjusting the position of the tool by controlling the movement of the robot along a predetermined coordinate axis in the traveling direction. That.

  According to a second aspect of the present invention, there is provided a rotation operation means, a detection means for detecting a rotation amount and a rotation direction of the rotation operation means, and a fine adjustment operation of a position of a tool provided in an end effector of the robot. A teaching device provided with an assigning means for assigning as means, a controller provided with a storage means for storing an inching amount and an operation coordinate system corresponding to a unit of rotation amount of the rotating operation means, and a control means for controlling the operation of the robot; When the rotation operation means is assigned as the position fine adjustment operation means by the assignment means, the teaching device detects the rotation amount and the rotation direction detected by the detection means. To the controller, and the control means corresponds to the motion coordinate system corresponding to the rotation amount and the rotation amount for each unit of the notified rotation amount. Along the axes of the predetermined traveling direction, it is an gist robot control system characterized by operating controls the robot.

  The invention of claim 3 is the welding torch according to claim 2, wherein the tool is arc welding, the motion coordinate system is a tool coordinate system, and the motion coordinate system corresponds to the rotation direction in advance. The coordinate axis of the determined advancing direction is a coordinate axis along the retract direction of the wire of the tool coordinate system, and the control means has the inching amount for each unit of the notified rotation amount and the tool coordinate system The robot is controlled to move along a coordinate axis along the retract direction of the wire. The invention of claim 4 is the welding torch for performing arc welding, wherein the tool is a welding line coordinate system according to claim 2, and the motion coordinate system corresponds to the rotation direction, The coordinate axis of the predetermined traveling direction is a coordinate axis along the welding direction of the welding line coordinate system, and the control means is the inching amount for each unit of the notified rotation amount and the welding line. The robot is controlled to move along coordinate axes along the welding direction of the coordinate system.

  As described above in detail, according to the first aspect of the invention, the operator performs the two steps of the step of setting the moving speed of the robot to the inching speed and the step of setting the coordinate system of the tool to the moving coordinate system. Therefore, the operation procedure for fine adjustment of the teaching position is reduced, so that it is possible to provide a fine adjustment method of the position of the tool of the robot that can reduce the teaching time. According to the first aspect of the present invention, it is possible to perform an intuitive fine adjustment of the teaching position only by rotating the rotation operation means without changing the axis operation key. Furthermore, in the case of fine adjustment operation, it can be moved along the coordinate axis in the predetermined traveling direction of the predetermined operation coordinate system only by operating the rotation operation means.

  According to the invention of claim 2, the operator is not required to perform the two steps of the step of setting the moving speed of the robot to the inching speed and the step of setting the coordinate system of the tool to the movement coordinate system. Since the operation procedure at the time of the fine adjustment is reduced, it is possible to provide a robot control system that can reduce the teaching time.

  According to a third aspect of the present invention, in the robot control system for controlling the arc welding robot, the effect of the second aspect is easily realized when the position is finely adjusted along the coordinate axis along the retract direction of the wire in the tool coordinate system. it can.

  According to the invention of claim 4, in the robot control system for controlling the arc welding robot, the effect of claim 2 can be easily realized when the position is finely adjusted along the coordinate axis along the welding direction of the welding coordinate system.

1 is a block diagram showing a configuration of a robot control system according to an embodiment embodying the present invention. Explanatory drawing of a tool coordinate system. (A)-(e) is explanatory drawing of a weld line coordinate system.

Hereinafter, an embodiment in which the present invention is embodied in a robot control system for controlling an arc welding robot will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the robot control system includes a teach pendant (hereinafter referred to as TP) 10 as a teaching device and a controller 20 that controls the operation of the robot R.

  The TP 10 is provided with a keyboard 11, a deadman switch (also referred to as an enable switch) 12, a rotation operation member 13 as a rotation operation means, and a rotary encoder 14 as a detection means for detecting the rotation direction and the rotation amount of the rotation operation member 13. Yes. The TP 10 includes a CPU 15, a ROM 16, and a RAM 17. The CPU 15 is a central processing unit. The ROM 16 stores various control programs for the CPU 15 to execute operations of the robot R and the like and communication with the controller 20, and control constants thereof. The RAM 17 is used as a working area for the CPU 15 and temporarily stores data being calculated.

  Further, the CPU 15 communicates various teaching data generated by the input operation of the keyboard 11, the on / off signal of the deadman switch 12, and the detection signal detected by the rotary encoder 14 to the controller 20 connected to the TP 10 (not shown). Notification via the department.

  Based on the detection signal of the rotary encoder 14, the rotation direction (including the normal rotation direction and the reverse rotation direction) and the rotation amount of the rotation operation member 13 are detected. The rotation amount is determined by counting the number of pulses with a counter (not shown) so that the rotary encoder 14 detects a pulse signal (detection signal) proportional to the rotation amount of the rotation operation member 13. I understand. In addition, the rotation direction can be determined by the rotary encoder 14 outputting, for example, a two-phase pulse, which is normal rotation or reverse rotation, that is, the rotation direction can be determined.

  The rotation operation member 13 is normally used as an operation tool for a pointer to move between menu items displayed on a display screen of a display device (not shown) provided in the TP 10. The menu items include a plurality of items, one of which includes “a fine adjustment operation item of a teaching position by a rotation operation member” which will be described later.

  In a normal case where there is no setting of a fine adjustment operation item of a teaching position by an enter key 11a described later, when the rotation operation member 13 is rotated, the CPU 15 corresponds to the rotation direction based on the detection signal of the rotary encoder 14. However, it is possible to move a pointer of a display device (not shown) to a menu item.

  The controller 20 controls the robot R so that arc welding is automatically performed on the workpiece (work object) W. The controller 20 is constituted by a computer including each part of a CPU 21, ROM 22, RAM 23, and storage device 24 as control means. The ROM 22 stores various control programs such as a control program for executing the operation control of the robot R to be controlled by the controller 20 and its control constants. The RAM 23 is used as a working area for the CPU 21 and temporarily stores data being calculated.

  The storage device 24 stores data teaching the work of the robot R, control program execution conditions, a key assignment table, and various control variables. The storage device 24 is registered with a work program as a work procedure based on commands and parameters sent from the TP 10 in the teaching mode. Further, the storage device 24 stores a mode state indicating whether the controller 20 is set to the teaching mode or the reproduction mode. This mode setting is performed by a mode setting instruction from the TP 10 or the like. In the present embodiment, the storage device 24 is configured by a hard disk, but is not limited to the hard disk, and may be another rewritable storage device.

In FIG. 1, the main control unit 25 is shown as functional blocks executed by the computer.
As shown in FIG. 1, the main control unit 25 includes a rotation operation member function allocation unit 25a, an interpretation execution unit 25b, an operation parameter setting unit 25c, and an operation control unit 25d. The rotation operation member function assignment unit 25a is configured by the key assignment table. Before performing the fine adjustment operation of the position of the welding torch T, the rotation operation member function assigning unit 25a rotates the rotation operation member 13 of the TP10, and among the menus displayed on the display device (not shown), The item “fine adjustment operation item of teaching position by member” is selected, and is read out from the storage device 24 by the pressing operation of the enter key 11 a of the keyboard 11 and developed in the RAM 23. The enter key 11a corresponds to an assigning unit.

  In the rotation operation member function assignment unit 25a (key assignment table), specifically, “forward rotation” of the rotation operation member 13 is assigned to a movement command in the positive direction of the Z axis in the tool coordinate system as the operation coordinate system. ing. Further, “reverse rotation” of the rotary operation member 13 is assigned to a movement command in the negative direction of the Z axis in the tool coordinate system.

  FIG. 2 shows the tool coordinate system. In the tool coordinate system, the retract direction of the wire Wa is the positive direction of the Z axis. Further, as shown in FIG. 2, in the present embodiment, the direction perpendicular to the Z axis is on the plane formed by the rotation center line O of the sixth axis of the robot R and the Z axis direction line Za. And the front direction of the torch is the positive direction of the X axis. The direction perpendicular to the X axis and the Z axis is the Y axis, and the direction follows the right-handed orthogonal coordinate system.

  The “rotation amount” for each unit of the rotation operation member 13 is assigned to the inching amount (movement amount). The unit is a value of a predetermined number of pulses. The inching amount is preferably the minimum amount of movement allowed for the robot R, but is not limited.

  The interpretation execution unit 25b interprets the rotation direction and the rotation amount of the rotary operation member 13 based on the detection signal of the rotary encoder 14 during the fine adjustment operation of the position, and according to the interpretation result, that is, the rotation direction is normal rotation. According to the rotation operation member function assignment unit 25a according to the reverse rotation and the rotation amount, the Z-axis plus direction movement command or the Z-axis minus direction movement command and the dimension according to the rotation amount A multiple of the amount of movement is output to the operation parameter setting unit 25c. The operation parameter setting unit 25c sets the operation parameter, that is, the control constant for performing the fine adjustment operation of the position based on the input movement command and a multiple of the inching amount corresponding to the rotation amount, and the operation control unit The movement command, a multiple of the inching amount, and a control constant are output to 25d. The motion control unit 25d controls the robot R based on the movement command, a multiple of the inching amount, and a control constant.

  The robot R includes a base member Ra fixed to a floor or the like, and a plurality of arms Rb connected via a plurality of axes. A welding torch T as a tool is provided on the end effector Rc at the distal end of the arm Rb located on the most distal side. The welding torch T includes a wire Wa as a filler material, generates an arc between the tip of the wire Wa fed by a feeding device (not shown) and the workpiece W, and welds the wire Wa with the heat. To weld the workpiece W. A plurality of motors (not shown) are disposed between the arms Rb, and the welding torch T can be freely moved back and forth and left and right by driving the motors.

  The controller 20 controls the motor to drive the welding torch T along the main track of preset teaching data. Further, the controller 20 outputs welding conditions such as a welding current and a welding voltage to a welding power source (not shown), and performs a welding operation with electric power supplied from the welding power source through a power cable (not shown).

(Function)
The operation of the robot control system configured as described above will be described.
When the operator performs a fine adjustment operation of the position of the welding torch T while operating the TP 10 in the teaching mode, the rotation operation member 13 of the TP 10 is rotated and displayed on a display device (not shown). In the menu, “fine adjustment operation item of teaching position by rotation operation member” is selected, and the enter key 11a of the keyboard 11 is pressed. By this operation, the main control unit 25 of the controller 20 expands the rotation operation member function allocation unit 25 a (key allocation table) read from the storage device 24 in the RAM 23.

  Thereafter, the operator performs a rotation operation for fine adjustment of the position of the rotation operation member 13 while the deadman switch 12 is pressed (ON state). The rotation operation of the rotation operation member 13 is detected by the rotary encoder 14, and the detection signal is sent (notified) to the controller 20.

  The interpretation execution unit 25b of the controller 20 interprets the rotation direction and the rotation amount of the rotary operation member 13 based on the detection signal of the rotary encoder 14, and according to the interpretation result, that is, the rotation direction is normal rotation, reverse rotation, and According to the rotation amount, referring to the rotation operation member function assigning unit 25a, the Z-axis plus direction movement command, the Z-axis minus direction movement command, and a multiple of the inching amount corresponding to the rotation amount It outputs to the operation parameter setting part 25c.

  Then, the operation parameter setting unit 25c sets the operation parameter, that is, the control constant for performing the fine adjustment operation of the position based on the input movement command and the multiple of the inching amount according to the rotation amount, The movement command, a multiple of the inching amount, and a control constant are output to the operation control unit 25d to the control unit 25d. The motion control unit 25d controls the robot R based on the movement command, a multiple of the inching amount, and a control constant.

Now, according to this embodiment, there are the following features.
(1) In the fine adjustment method of the position of this embodiment, the rotation operation member 13 (rotation operation means) provided in TP10 (teaching device) is welded to the welding torch by the enter key 11a (assignment means) provided in TP10. Assigned as fine adjustment operation means for the position of T (tool). Next, when the rotation operation member 13 is operated, the rotary encoder 14 (detection means) detects the rotation amount and rotation direction of the rotation operation member 13 and notifies the controller 20 of the rotation amount and rotation direction. Next, the CPU 21 (control means) of the controller 20 determines a predetermined tool coordinate system (operation) corresponding to the rotation direction with a predetermined inching amount for each unit of the notified rotation amount. The robot R is controlled in motion along a predetermined Z-axis (coordinate axis in the traveling direction) of the coordinate system) to finely adjust the position of the welding torch T (tool).

  As a result, according to the fine adjustment method of the position of the present embodiment, the operator sets the moving speed of the robot R to the inching speed, and sets the coordinate system of the welding torch T to the operating coordinate system. No process work is required. And since the operation procedure at the time of fine adjustment of a teaching position decreases, teaching time can be reduced. Further, according to the fine adjustment method of the position of the present embodiment, an intuitive fine adjustment operation of the teaching position can be performed only by rotating the rotary operation member 13 without changing the axis operation key. Furthermore, when performing a fine adjustment operation of the position, the position can be moved along a predetermined Z axis of a predetermined tool coordinate system only by operating the rotation operation member 13.

  (2) According to the robot control system of the present embodiment, when the rotation operation member 13 (rotation operation means) is assigned as the fine adjustment operation means by the enter key 11a (assignment means), the TP 10 The controller 20 is notified of the rotation amount and the rotation direction detected by the encoder 14. The CPU 21 (control means) of the controller 20 moves the robot R along the predetermined Z axis of the tool coordinate system in accordance with the rotation amount and the inching amount for each unit of the notified rotation amount. Control the operation.

  As a result, according to the robot control system of the present embodiment, when performing conventional fine adjustment, it is necessary to switch a plurality of settings by key operation. By handling it as a group of functions, setting errors can be prevented and the operating procedure can be reduced. Conventionally, when finely adjusting the position, it is necessary to press the plus / minus direction key of the operation target axis. However, the rotation operation member 13 rotates to move in the plus / minus direction. Can be performed with an inching amount according to the unit of rotation amount, an intuitive fine adjustment is possible, and operability can be greatly improved.

  (3) According to the robot control system of this embodiment, the motion coordinate system is the tool coordinate system. In correspondence with the rotation direction of the rotation operation member 13, a predetermined Z-axis of the tool coordinate system is a coordinate axis along the retract direction of the wire Wa of the tool coordinate system. Then, the CPU 21 of the controller 20 controls the operation of the robot R along the Z axis along the retract direction of the wire Wa of the tool coordinate system by the inching amount for each unit of the notified amount of rotation. As a result, in the robot control system for controlling the arc welding robot, when the position is finely adjusted along the Z axis along the retract direction of the wire Wa in the tool coordinate system, the effect (2) can be easily realized. .

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the tool coordinate system is used, but a weld line coordinate system may be used. The weld line coordinate system will be described with reference to FIGS.

  The welding line coordinate system first considers a plane H perpendicular to the welding direction (Z axis), and then projects a welding torch T onto the plane H perpendicular to the Z axis as shown in FIG. . After the projection, the retracting direction of the welding torch T becomes the positive direction of the X axis (see FIG. 3C). The Y axis is a right-handed orthogonal coordinate system and is a direction orthogonal to the Z axis and the X axis. In FIGS. 3C and 3D, W1 and W2 are workpieces.

In the present embodiment, when the operation coordinate system is the welding line coordinate system, each teaching point on the already taught welding line can be finely adjusted in the welding direction.
In the above-described embodiment, the robot control system of the welding robot is embodied. However, the invention is not limited to the robot control system of the welding robot, and can be applied to a robot control system that finely adjusts the position of a tool that is not a welding torch. Of course.

  In the embodiment, the rotation operation member 13 selects the “fine adjustment operation item of the teaching position by the rotation operation member” from the menu items of the display device (not shown) and presses the enter key of the keyboard 11. . Instead of supporting the rotation operation member 13 in a rotatable manner, the rotation operation member 13 is provided so as to be capable of being pressed and moved in a direction orthogonal to or axially with respect to the shaft that is rotatably supported. A switch that is turned on by pressing movement may be provided. In this case, the pressing operation of the switch can be replaced with the operation of the enter key. This switch corresponds to the assigning means.

  In the embodiment described above, the “fine adjustment operation item of the teaching position by the rotation operation member” is selected from the menu items of the display device (not shown) by the rotation operation member 13. Before performing the fine adjustment operation, a function setting key (not shown) provided on the keyboard 11 of the TP 10 may be operated to declare a fine adjustment operation item of the teaching position by the rotation operation member. In this case, when the operator presses the function setting key, the fine adjustment operation means is set based on this key operation. In this case, the function setting key corresponds to the assigning means.

  -In the said embodiment, although embodied in the robot control system of an arc welding robot, it is not limited to the robot control system of an arc welding robot, It can apply to the robot control system for performing the teaching by fine adjustment movement.

10 ... TP (teaching device), 11a ... Enter key (assignment means),
13 ... Rotation operation member (rotation operation means),
14 ... Rotary encoder (detection means), 20 ... Controller,
21 ... CPU (control means), T ... welding torch (tool),
Wa ... Wire.

Claims (4)

Assigning the rotation operation means provided in the teaching device as the fine adjustment operation means of the position of the tool provided in the end effector of the robot by the assignment means provided in the teaching device;
A step of causing the detection means to detect a rotation amount and a rotation direction of the rotation operation means when the rotation operation means is operated, and notifying the controller of the rotation amount and the rotation direction;
The control means provided in the controller has a predetermined motion coordinate system in a predetermined amount of movement and corresponding to the rotation direction for each unit of the notified rotation amount. A method for finely adjusting a position of a tool of a robot, wherein the movement of the robot is controlled along a coordinate axis in a traveling direction to finely adjust the position of the tool. Rotation operation means, detection means for detecting the amount and direction of rotation of the rotation operation means, and assignment means for assigning the rotation operation means as fine adjustment operation means for the position of a tool provided on the end effector of the robot; And a controller having a storage means for storing an inching amount and a motion coordinate system according to a unit of rotation amount of the rotation operation means and a control means for controlling the operation of the robot. And
When the rotation operation means is assigned by the assignment means as the position fine adjustment operation means, the teaching device notifies the controller of the rotation amount and the rotation direction detected by the detection means,
The control means operates the robot along the coordinate axis of the motion coordinate system in a predetermined traveling direction corresponding to the rotation direction and corresponding to the rotation direction for each unit of the notified rotation amount. A robot control system characterized by controlling. The tool is a welding torch for performing arc welding;
The motion coordinate system is a tool coordinate system;
Corresponding to the rotation direction, a coordinate axis in a predetermined traveling direction of the motion coordinate system is a coordinate axis along the retract direction of the wire of the tool coordinate system,
The control means controls the movement of the robot along the coordinate axis along the retract direction of the wire in the tool coordinate system with the inching amount for each unit of the notified rotation amount. The robot control system according to 2. The tool is a welding torch for performing arc welding;
The motion coordinate system is a weld line coordinate system;
Corresponding to the rotation direction, a coordinate axis in a predetermined traveling direction of the motion coordinate system is a coordinate axis along the welding direction of the welding line coordinate system,
The control means controls the operation of the robot along the coordinate axis along the welding direction of the welding line coordinate system with the inching amount for each unit of the notified rotation amount. The robot control system according to 2.

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