Tandem Arc Welding Robot Controller Rotational Center Correction
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Solution Overview
Problem
Existing tandem arc welding systems face issues with defective welding due to displacement of the leading electrode during arc tracking, particularly when the rotational center is set between the leading and trailed electrodes, leading to incorrect weld penetration.
Innovation Solution
A robot controller that calculates and corrects the position of the rotational center of the welding torch using leading-electrode and trailed-electrode correction amounts, ensuring the leading electrode remains stationary by adjusting the teaching position and rotational center, thereby preventing displacement and defective welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the TCP is set at the leading electrode to perform arc tracking, then the arc tracking of the trailed electrode can be performed, but the position of the leading electrode changes during welding, causing defective welding
Solution Approach 1:
The patent introduces an intermediate calculation process that computes the displacement of the leading electrode caused by the arc tracking of the trailed electrode. This intermediate displacement value is then used to calculate a rotational center correction amount, which acts as a mediator to compensate for the position change and maintain welding accuracy.
Solution Approach 2:
The patent performs preliminary calculation of the leading electrode's displacement and the required rotational center correction before executing the arc tracking. By pre-calculating the correction amount based on the distance between the TCP and leading electrode, the system prepares the compensation values in advance to prevent position deviation during welding.
2Adaptability or versatility
If the TCP is set at an intermediate position between the leading and trailed electrodes, then the operation flexibility is improved, but the leading electrode position changes during arc tracking, causing defective welding
Solution Approach 1:
The patent uses the displacement calculation as an intermediary step that works regardless of where the TCP is positioned. Whether TCP is at the leading electrode or at an intermediate position, the system calculates how much the leading electrode moves due to trailed electrode tracking, and applies appropriate correction to maintain precision while preserving operational flexibility.
Solution Approach 2:
The patent implements a dynamic correction mechanism that adapts to the TCP position. The rotational center correction amount is calculated based on the distance between the TCP and the leading electrode, allowing the system to dynamically adjust the compensation based on the configured TCP position, thereby maintaining both flexibility and precision.
3Ease of operation
If arc tracking is performed by rotating the trailed electrode around the leading electrode, then the arc tracking function is achieved, but the teaching position must be corrected when changing operation direction
Solution Approach 1:
The patent performs preliminary calculation of the rotational center correction amount during the teaching phase, storing this correction value for future use. When the operation direction is changed, the pre-calculated correction amount can be applied directly without requiring re-teaching or time-consuming adjustments, thus reducing the loss of time.
Solution Approach 2:
The patent establishes a feedback mechanism where the displacement of the leading electrode is calculated based on the arc tracking of the trailed electrode, and this feedback information is used to automatically adjust the rotational center position. This closed-loop approach eliminates the need for manual teaching position corrections when changing operation directions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents displacement of the leading electrode during arc tracking, ensuring accurate weld penetration and preventing defective welding by precisely controlling the rotational center and teaching position, even when arc tracking is performed at any rotational center between the electrodes.
Implementation Method 1
a welding power supply 4 that supplies electric power to the leading electrode 2a and the trailed electrode 2b
Data Source
AI summary
A robot controller that controls a tandem arc welding system according to the present invention includes a leading-electrode correcting section that calculates a leading-electrode correction amount, used for correcting a displacement in a left-right direction and an up-down direction, from a leading-electrode changing amount calculated by a leading-electrode processing section; a leading-electrode correcting section that calculates a trailed-electrode correction amount, used for correcting a displacement in a rotational direction, from a trailed-electrode changing amount calculated by a trailed-electrode processing section; a rotational-displacement correction controlling processing section that calculates a rotational-center correction amount for correcting the displacement of the leading electrode; and a robot trajectory planning processing section that corrects a teaching position and a position of a rotational center of a welding torch during tracking correction. By such a structure, even if arc tracking is carried out at any rotational center, displacement of the leading electrode does not occur, so that defective welding does not occur.