Welding robot

Abstract

The invention provides a welding robot which makes it possible to, in a seam tracking operation during tandem welding, realize a high tracking ability, not only for a leading electrode, but also for a trailed electrode. A translational correction calculating unit (23) corrects a target value Plead(t) of the leading electrode (5a) using a translational correction amount Delta P(t) in a base coordinate system Sigmabase for a next time position of the leading electrode (5a), to obtain a primary correction target value Plead(t)'. A rotational correction calculating unit (24) calculates a rotation correction amount Delta theta(t) for correcting displacement of an orientation of a torch (6) around the leading electrode (5a) with respect to a actual weld line Lre generated because of the translational correction amount Delta P(t), and calculates a secondary correction target value Plead(t)'' resulting from correcting the primary correction target value Plead(t)' so that the torch (6) rotates around the leading electrode (5a) by the rotation correction amount Delta theta(t). A manipulator (2) is driven on the basis of the secondary correction target value Plead(t)''.

Description

technical field [0001] The invention relates to a welding robot. More specifically, the present invention relates to a welding robot that performs seam tracking in tandem welding. Background technique [0002] For automatic welding equipment such as welding robots, "Seam Tracking" that automatically tracks weld seams with various sensors is widely used. The purpose of seam tracking is to prevent welding defects by detecting and correcting the deviation of the welding target position due to machining errors, setting errors, and dynamic errors of the welding process caused by thermal deformation, etc. . Figure 13 Schematic representation of the principle of seam tracking. As the sensor 1 used, there are a mechanical sensor, a sensor using a change in arc welding current, an optical-visual sensor, and the like. Even though the sensor 1 has different methods, the principle is the same from the following point of view, that is, the signal measured by the sensor 1 is processed...

AI Technical Summary

Problems solved by technology

In order to reduce the correction amount due to tracking, not only the machining accuracy of the workpiece to be welded must be improved, but also the manufacturing aspects such as minimizing the positional deviation during installation and welding thermal deformation must be spent, which leads to the inherent cost of correcting these errors. The purpose is that seam tracking cannot function effectively as a result

[0006] Second, the operation is troublesome and becomes the cause of human error

However, in this method, when the program is executed, the operator is forced to sequentially input which electrode to select while grasping the traveling direction of welding.

In addition, there is also the possibility of an illegal tracking method that is selected for tracking based on the current change value of the subsequent electrode due to an input error

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