Image-Guided Welding Control for Electrode-Wire Alignment

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Solution Overview

Problem

Automatic arc welding systems using non-consumable electrodes face complexity in controlling the relative positions of the electrode and weld wire, leading to potential misalignment and reduced welding quality due to changing heat input conditions.

Innovation Solution

A welding control device that determines target positions based on weld conditions through image processing, using machine learning to adjust the positions of the electrode and weld wire relative to the molten pool and groove, thereby maintaining optimal alignment and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate control of electrode and weld wire positions is implemented, then welding precision is improved, but device complexity increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidcontrol complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the control of electrode position and weld wire position into a unified control system. The position control unit simultaneously manages both components based on their detected actual positions, merging what would otherwise be separate control mechanisms into one integrated system that reduces overall complexity while maintaining precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements feedback control by detecting the actual positions of both the electrode and weld wire, comparing them to target positions, and automatically adjusting them accordingly. This closed-loop feedback mechanism enables precise positioning without requiring complex manual intervention or overly complicated control systems.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If constant relative distance between weld wire and molten pool is maintained, then welding quality is improved, but risk of electrode-wire contact increases when molten pool size changes

Engineering Contradiction:
Improvewelding qualityVSAvoidcontact prevention
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent dynamically adjusts the target position of the weld wire based on the detected size of the molten pool. When the molten pool becomes smaller, the system automatically modifies the wire's target position to maintain appropriate spacing, preventing contact with the electrode. This dynamic adjustment capability allows the system to adapt to changing welding conditions in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the target position parameter of the weld wire in response to changes in molten pool dimensions. By adjusting this parameter dynamically rather than maintaining a fixed distance, the system prevents electrode-wire contact while preserving welding quality across varying operational conditions.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If automatic welding control is implemented without skill-based adjustment, then productivity is improved, but welding quality may deteriorate

Engineering Contradiction:
Improveautomation levelVSAvoidwelding quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent enables the welding system to automatically detect and correct its own positioning deviations without external human intervention. The position detection unit continuously monitors actual positions, and the position control unit autonomously adjusts electrode and wire positions to match target positions, allowing the system to serve itself and maintain high-quality welding at automated speeds.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical skill-based adjustment performed by human welders with an automated detection and control system. Instead of relying on a welder's expertise to manually adjust positions, the system uses sensors and control algorithms to automatically maintain optimal positioning, preserving welding quality while enabling full automation and high productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 system enables automatic arc welding with reduced dependency on skilled welders, achieving welding quality similar to that of human operators by continuously adjusting positions in response to changing conditions.

Implementation Method 1

an electrode for melting the weld wire

Methodology Applied
Scientific EffectElectric Arc: Electric Arc

Data Source

PatentEP3753663B1Welding control device, welding control method, and welding control program
Publication Date: 2023.11.29 MITSUBISHI HEAVY IND LTD
  • EP3753663B1 patent drawingFigure 1
  • EP3753663B1 patent drawingFigure 2
  • EP3753663B1 patent drawingFigure 3A

AI summary

A welding control device is configured to control a position control target including at least one of a weld wire used in welding of a weld target or an electrode for melting the weld wire. The welding control device includes: an actual position determination part configured to determine an actual position of the position control target on the basis of a weld characteristic amount detected from a captured image captured so as to include at least the position control target, the weld characteristic amount including at least one of a wire position of the weld wire or an electrode position of the electrode; a target position determination part configured to determine a target position being a target of the actual position corresponding to a weld condition for welding the weld target; and a position control part configured to execute a position control of the position control target to bring the actual position to the target position.