A method for controlling a welding robot, a welding control device, a welding system, a welding method, and a control program for a welding robot.

Abstract

To provide a control method of a welding robot having robot moving speed control corresponding to torch angle control in order to obtain excellent bead appearance, a welding control device, a welding system, a welding method, and a control program of the welding robot.SOLUTION: A control method of a welding robot is characterized in that: when only a guide rail out of the guide rail and a workpiece is a curved surface portion in a region I and a region III, controls of (A) to (D) are performed on the basis of a torch angle correction amount calculated and set by a control condition calculation unit, and controls of (E) to (G) are performed on the basis of a robot moving speed calculated and set by the control condition calculation unit; and meanwhile, when only the workpiece of the guide rail and the workpiece is a curved surface portion in the region I and the region III, controls of (H) to (K) are performed on the basis of the torch angle correction amount calculated and set by the control condition calculation unit, and controls of (L) to (N) are performed on the basis of the robot movement speed calculated and set by the control condition calculation unit.SELECTED DRAWING: Figure 14

Claims

1. A welding robot control method using a welding system comprising: a welding robot that moves along a guide rail having a curved section to arc-weld a workpiece having a corner section; and a welding control device that controls the welding robot, the welding robot being installed on the guide rail. The welding control device is A welding condition setting unit that sets welding conditions at a predetermined torch target position, A control condition calculation unit calculates control conditions for controlling the welding robot so that the welding conditions set by the welding condition setting unit are met, Equipped with, A target position determination step in which the torch target position is determined based on at least guide rail information and workpiece information, A region determination step in which a region is determined based on the torch target position, A control condition determination step in which, for each region determined in the region determination step, the control condition calculation unit calculates the control condition and sets the control condition, It has, In the aforementioned region determination step, the region to be determined is divided into at least the following regions I to IV: - Region I: A region on the welding start position side where only one of the guide rail or the workpiece is a curved surface. - Region II: The region where both the guide rail and the workpiece are curved surfaces. - Region III: A region where only one of the guide rail or the workpiece is a curved surface on the welding end position side. - Region IV: The region where both the guide rail and the workpiece are straight sections. In the control condition determination step, the control condition includes at least the torch angle correction amount and the robot movement speed, In regions I and III, if only the guide rail is the curved portion among the guide rail and the workpiece, Based on the torch angle correction amount calculated and set by the control condition calculation unit, the following controls (A) to (D) are performed: - Control (A): Control is performed to tilt the torch angle toward the welding forward direction from approximately the starting position of the region I to approximately the ending position of the region I or near the ending position of the region I. - Control (B): Control is performed to tilt the torch angle toward the welding retreat direction so that the torch angle correction amount approaches 0 or near 0, from approximately the starting position of region II to approximately the center position of region II. - Control (C): Control is performed to tilt the torch angle toward the welding retraction direction from approximately the center position of region II to approximately the end position of region II. - Control (D): Control is performed to tilt the torch angle toward the welding forward direction so that the torch angle correction amount approaches 0 or near 0, from the approximate start position of region III to the approximate end position of region III. A method for controlling a welding robot, characterized in that the following controls (E) to (G) are performed based on the robot movement speed calculated and set by the control condition calculation unit. - Control (E): Control of at least one of the following intervals (a) to (c) in the region I. - Section (a): A control section in which deceleration occurs at approximately the starting position of the region I. - Section (b): A control section in which the torch is accelerated within the region I at a first incline or to a predetermined set value for the torch target position. - Section (c): A control section in which the torch accelerates toward the approximate end position of the aforementioned region I with a second incline, or to a predetermined set value for the torch target position. - Control (F): Control is performed in region II for at least one of the following intervals (d) to (f). - Section (d): A control section in which acceleration or deceleration occurs at approximately the start position of the aforementioned region II, according to the velocity at approximately the end position of the aforementioned region I. - Section (e): A control section within the aforementioned region II that decelerates to approximately the center of region II. - Section (f): A control section within the region II that accelerates from approximately the center position of region II to approximately the end position. - Control (G): Control is performed in region III for at least one of the following intervals (g) to (h). - Section (g): A control section in which the vehicle decelerates at approximately the starting position of the area III with a third incline, or to a predetermined set value for the torch target position. - Section (h): A control section within the area III in which the vehicle decelerates with a fourth incline toward the approximate end of area III, or to a predetermined set value for the torch target position.

2. A welding robot control method using a welding system comprising: a welding robot that moves along a guide rail having a curved section to arc-weld a workpiece having a corner section; and a welding control device that controls the welding robot, the welding robot being installed on the guide rail. The welding control device is A welding condition setting unit that sets welding conditions at a predetermined torch target position, A control condition calculation unit calculates control conditions for controlling the welding robot so that the welding conditions set by the welding condition setting unit are met, Equipped with, A target position determination step in which the torch target position is determined based on at least guide rail information and workpiece information, A region determination step in which a region is determined based on the torch target position, A control condition determination step in which, for each region determined in the region determination step, the control condition calculation unit calculates the control condition and sets the control condition, It has, In the aforementioned region determination step, the region to be determined is divided into at least the following regions I to IV: - Region I: A region on the welding start position side where only one of the guide rail or the workpiece is a curved surface. - Region II: The region where both the guide rail and the workpiece are curved surfaces. - Region III: A region where only one of the guide rail or the workpiece is a curved surface on the welding end position side. - Region IV: The region where both the guide rail and the workpiece are straight sections. In the control condition determination step, the control condition includes at least the torch angle correction amount and the robot movement speed, In regions I and III, if only the workpiece is the curved portion among the guide rail and the workpiece, Based on the torch angle correction amount calculated and set by the control condition calculation unit, the following control (H) to (K) is performed: - Control (H): Control that tilts the torch angle toward the welding retreat direction from approximately the start position of region I to approximately the end position of region I or near the end position of region I. - Control (I): Control to tilt the torch angle toward the welding forward direction so that the torch angle correction amount approaches 0 or near 0, from approximately the starting position of region II to approximately the center position of region II. • Control (J): Control to tilt the torch angle toward the welding forward direction from approximately the center position of region II to approximately the end position of region II. - Control (K): Control that tilts the torch angle toward the welding retreat direction so that the torch angle correction amount approaches 0 or near 0 from approximately the start position of region III to approximately the end position of region III. A control method for a welding robot, characterized in that the following control (L) to (N) is performed based on the robot movement speed calculated and set by the control condition calculation unit. - Control (L): Control is performed in region I for at least one of the following intervals (i) to (k). - Section (i): A control section in which acceleration occurs approximately at the starting position of the region I. - Section (j): A control section within the aforementioned region I where deceleration occurs at a fifth incline or to a predetermined torch target position setting. - Section (k): A control section in which the vehicle decelerates toward the approximate end position of the aforementioned region I with a sixth incline, or to a predetermined set value for the torch target position. - Control (M): Control is performed in region II for at least one of the following intervals (l) to (n). - Section (l): A control section in which acceleration or deceleration occurs at approximately the starting position of the aforementioned region II, according to the velocity at approximately the ending position of the aforementioned region I. - Section (m): A control section within the aforementioned region II that accelerates to approximately the center of region II. - Section (n): A control section within the region II that decelerates from approximately the center position of region II to approximately the end position. - Control (N): Control is performed in region III for at least one of the following intervals (o) to (p). - Section (o): A control section in which the torch accelerates at approximately the starting position of the aforementioned region III with a seventh incline, or to a predetermined set value for the torch target position. - Section (p): A control section within the aforementioned region III, accelerating towards the approximate end position of region III with an eighth incline, or to a predetermined set value for the torch target position.

3. The absolute value of the second slope is greater than the absolute value of the first slope. The absolute value of the third slope is greater than the absolute value of the fourth slope. A method for controlling a welding robot according to claim 1.

4. In the region I, a control section is provided in which deceleration occurs instantaneously at least approximately the starting position of the region I. In the region I, at least one of the following is provided: a control section that accelerates with the first slope, and a control section that accelerates with the second slope toward the approximate end position of the region I. A method for controlling a welding robot according to claim 1.

5. In the control section where acceleration occurs with the second slope toward the approximate end position of the region I, The target setting value for the robot's movement speed at approximately the end of region I is greater than the setting value for region IV. A method for controlling a welding robot according to claim 1.

6. When the distances d2 and d1 in the welding direction between region I and region III are the same, The target setting value for the robot's movement speed at approximately the end of region I is set to the maximum speed in region II. In the aforementioned region II, a control section is provided for deceleration from approximately the starting position of region II, where the maximum speed is reached, to approximately the center position, and a control section is provided for acceleration from approximately the center position of region II to approximately the end position, with a target speed approximately the same as the starting position of region II as the target setting value. The welding robot control method according to claim 5.

7. When the distances d2 and d1 in the welding direction between region I and region III are different, When the distance d2 in the welding direction of region I is greater than the distance d1 in the welding direction of region III, the target setting value of the robot movement speed at the approximate starting position of region II is set to the maximum speed in region II. When the distance d1 in the welding direction of region III is greater than the distance d2 in the welding direction of region I, the target setting value of the robot movement speed at the approximate end position of region II is set to the maximum speed in region II. The welding robot control method according to claim 5.

8. The aforementioned control conditions further include a correction amount in the groove depth direction, Based on the groove depth correction amount calculated and set by the control condition calculation unit, control is performed to move away from the welding position from the starting position of region I to the center position of region II, and control is performed to move closer to the welding position from the center position of region II to the end position of region III. A method for controlling a welding robot according to claim 1.

9. In the region I, at least a control section is provided in which acceleration occurs instantaneously at approximately the starting position of the region I. In the region I, a control section is provided in which deceleration occurs with the fifth slope, and a control section is provided in which deceleration occurs with the sixth slope toward the approximate end position of the region I. The absolute value of the sixth slope is greater than the absolute value of the fifth slope. The method for controlling a welding robot according to claim 2.

10. The aforementioned control conditions further include a correction amount in the groove depth direction, Based on the correction amount in the groove depth direction calculated and set by the control condition calculation unit, control is performed to move the welding position closer from the starting position of region I to the central position of region II, and control is performed to move the welding position away from the welding position from the central position of region II to the ending position of region III. The method for controlling a welding robot according to claim 2.

11. Based on the guide rail information and the workpiece information, it is determined whether the curved portion of the guide rail and the corner portion of the workpiece are located on concentric circles or non-concentric circles. If located on concentric circles, it is determined to be type A; if located on non-concentric circles, it is determined to be type B or type C. Furthermore, in the case where the location is not on a concentric circle, if only the guide rail among the guide rail and the workpiece is the curved portion in region I and region III, it is determined to be type B, and if only the workpiece among the guide rail and the workpiece is the curved portion in region I and region III, it is determined to be type C, characterized in that the welding robot control method according to claim 1 or 2.

12. Based on the distance in the welding direction between region I and region III calculated based on the guide rail information and the workpiece information, or based on a preset distance in the welding direction between region I and region III, it is determined whether the curved portion of the guide rail and the corner portion of the workpiece are located on concentric circles or not. The welding robot control method according to claim 11.

13. The control of the robot's movement speed from section (c) of region I to section (g) of region III, or the control of the robot's movement speed from section (k) of region I to section (o) of region III, is controlled to be substantially symmetrical with respect to the central position of region II. A method for controlling a welding robot according to claim 1 or 2, characterized in that it is a welding robot control method according to claim 1 or 2.

14. A welding control device for controlling a welding robot that moves along a guide rail having a curved section to arc weld a workpiece having a corner section, wherein the robot is positioned on the guide rail and arc welds the workpiece. The welding control device is A welding condition setting unit that sets welding conditions at a predetermined torch target position, A control condition calculation unit calculates control conditions for controlling the welding robot so that the welding conditions set by the welding condition setting unit are met, Equipped with, Based at least the guide rail information and the workpiece information, the torch target position is determined, Based on the aforementioned torch target position, the area is determined, For each determined region, the control condition calculation unit calculates the control condition and sets the control condition. The area to be determined is divided into at least the following areas I to IV: - Region I: A region on the welding start position side where only one of the guide rail or the workpiece is a curved surface. - Region II: The region where both the guide rail and the workpiece are curved surfaces. - Region III: A region where only one of the guide rail or the workpiece is a curved surface on the welding end position side. - Region IV: The region where both the guide rail and the workpiece are straight sections. The aforementioned control conditions include at least the torch angle correction amount and the robot movement speed, In regions I and III, if only the guide rail is the curved portion among the guide rail and the workpiece, Based on the torch angle correction amount calculated and set by the control condition calculation unit, the following controls (A) to (D) are performed: - Control (A): Control is performed to tilt the torch angle toward the welding forward direction from approximately the starting position of the region I to approximately the ending position of the region I or near the ending position of the region I. - Control (B): Control is performed to tilt the torch angle toward the welding retreat direction so that the torch angle correction amount approaches 0 or near 0, from approximately the starting position of region II to approximately the center position of region II. - Control (C): Control is performed to tilt the torch angle toward the welding retraction direction from approximately the center position of region II to approximately the end position of region II. - Control (D): Control is performed to tilt the torch angle toward the welding forward direction so that the torch angle correction amount approaches 0 or near 0, from the approximate start position of region III to the approximate end position of region III. A welding control device characterized in that the following controls (E) to (G) are performed based on the robot movement speed calculated and set by the control condition calculation unit. - Control (E): Control of at least one of the following intervals (a) to (c) in the region I. - Section (a): A control section in which deceleration occurs at approximately the starting position of the region I. - Section (b): A control section in which the torch is accelerated within the region I at a first incline or to a predetermined set value for the torch target position. - Section (c): A control section in which the torch accelerates toward the approximate end position of the aforementioned region I with a second incline, or to a predetermined set value for the torch target position. - Control (F): Control is performed in region II for at least one of the following intervals (d) to (f). - Section (d): A control section in which acceleration or deceleration occurs at approximately the start position of the aforementioned region II, according to the velocity at approximately the end position of the aforementioned region I. - Section (e): A control section within the aforementioned region II that decelerates to approximately the center of region II. - Section (f): A control section within the region II that accelerates from approximately the center position of region II to approximately the end position. - Control (G): Control is performed in region III for at least one of the following intervals (g) to (h). - Section (g): A control section in which the vehicle decelerates at approximately the starting position of the area III with a third incline, or to a predetermined set value for the torch target position. - Section (h): A control section within the area III in which the vehicle decelerates with a fourth incline toward the approximate end of area III, or to a predetermined set value for the torch target position.

15. A welding control device for controlling a welding robot that moves along a guide rail having a curved section to arc weld a workpiece having a corner section, wherein the robot is positioned on the guide rail and arc welds the workpiece. The welding control device is A welding condition setting unit that sets welding conditions at a predetermined torch target position, A control condition calculation unit calculates control conditions for controlling the welding robot so that the welding conditions set by the welding condition setting unit are met, Equipped with, Based at least the guide rail information and the workpiece information, the torch target position is determined, Based on the aforementioned torch target position, the area is determined, For each determined region, the control condition calculation unit calculates the control condition and sets the control condition. The area to be determined is divided into at least the following areas I to IV: - Region I: A region on the welding start position side where only one of the guide rail or the workpiece is a curved surface. - Region II: The region where both the guide rail and the workpiece are curved surfaces. - Region III: A region where only one of the guide rail or the workpiece is a curved surface on the welding end position side. - Region IV: The region where both the guide rail and the workpiece are straight sections. The aforementioned control conditions include at least the torch angle correction amount and the robot movement speed, In regions I and III, if only the workpiece is the curved portion among the guide rail and the workpiece, Based on the torch angle correction amount calculated and set by the control condition calculation unit, the following control (H) to (K) is performed: - Control (H): Control that tilts the torch angle toward the welding retreat direction from approximately the start position of region I to approximately the end position of region I or near the end position of region I. - Control (I): Control to tilt the torch angle toward the welding forward direction so that the torch angle correction amount approaches 0 or near 0, from approximately the starting position of region II to approximately the center position of region II. • Control (J): Control to tilt the torch angle toward the welding forward direction from approximately the center position of region II to approximately the end position of region II. - Control (K): Control that tilts the torch angle toward the welding retreat direction so that the torch angle correction amount approaches 0 or near 0 from approximately the start position of region III to approximately the end position of region III. A welding control device characterized in that the following controls (L) to (N) are performed based on the robot movement speed calculated and set by the control condition calculation unit. - Control (L): Control is performed in region I for at least one of the following intervals (i) to (k). - Section (i): A control section in which acceleration occurs approximately at the starting position of the region I. - Section (j): A control section within the aforementioned region I where deceleration occurs at a fifth incline or to a predetermined torch target position setting. - Section (k): A control section in which the vehicle decelerates toward the approximate end position of the aforementioned region I with a sixth incline, or to a predetermined set value for the torch target position. - Control (M): Control is performed in region II for at least one of the following intervals (l) to (n). - Section (l): A control section in which acceleration or deceleration occurs at approximately the starting position of the aforementioned region II, according to the velocity at approximately the ending position of the aforementioned region I. - Section (m): A control section within the aforementioned region II that accelerates to approximately the center of region II. - Section (n): A control section within the region II that decelerates from approximately the center position of region II to approximately the end position. - Control (N): Control is performed in region III for at least one of the following intervals (o) to (p). - Section (o): A control section in which the torch accelerates at approximately the starting position of the aforementioned region III with a seventh incline, or to a predetermined set value for the torch target position. - Section (p): A control section within the aforementioned region III, accelerating towards the approximate end position of region III with an eighth incline, or to a predetermined set value for the torch target position.

16. The welding robot and, A welding control device according to claim 14 or 15 for controlling the welding robot, A welding system characterized by comprising:

17. A welding method using the welding system described in claim 16.

18. A program for causing a welding control device that controls the welding robot to function according to claim 1 or 2.

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