Arc Welding Control via Light Intensity and Current Feedback

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing welding systems face challenges in accurately controlling the arc length during gas metal arc welding due to difficulties in determining the voltage drop across the welding arc, which affects the consistency of the weld bead profile and penetration depth.

Innovation Solution

A welding system that includes sensors to detect light intensity and current, with control circuitry modifying the light intensity signal based on current to accurately determine and control the arc length, providing more precise feedback than traditional voltage drop measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If voltage feedback is used to maintain uniform arc length, then weld bead profile and penetration depth consistency is improved, but measurement accuracy deteriorates due to difficulty in accurately determining voltage drop across the welding arc

Engineering Contradiction:

Improveweld bead profile consistencyVSAvoidvoltage drop measurement accuracy

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent introduces light intensity as an intermediary measurement parameter to indirectly determine arc length. Instead of directly measuring voltage drop across the arc (which is difficult due to unknown electrode extension), the system measures light intensity emitted by the arc, which correlates with arc length, and uses this as a proxy to control arc length maintenance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the electrical measurement system (voltage feedback) with an optical measurement system (light intensity sensing). By substituting the mechanical/electrical approach of measuring voltage drop with an optical approach of measuring light emission, the system achieves more accurate arc length determination without the limitations of voltage measurement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If electrode extension changes are not accounted for in voltage measurement, then measurement simplicity is maintained, but measurement precision deteriorates

Engineering Contradiction:

Improvemeasurement simplicityVSAvoidarc length measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses light intensity as an intermediary that is unaffected by electrode extension changes. Unlike voltage measurement which requires accounting for variable electrode extension, light intensity directly reflects arc length regardless of how much the electrode extends, eliminating the need to measure or account for electrode extension separately.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If traditional voltage feedback control is used, then system complexity is minimized, but manufacturing precision deteriorates due to inaccurate arc length control

Engineering Contradiction:

Improvecontrol system complexityVSAvoidarc length control accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces the traditional voltage feedback control system with an optical feedback control system. By substituting voltage measurement with light intensity measurement, the system achieves more accurate arc length control while maintaining relatively simple system architecture through the use of straightforward optical sensing and feedback mechanisms.

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

This approach allows for more accurate control of the welding arc length, resulting in consistent weld bead profiles and penetration depths, and enables automatic adjustments to maintain desired arc lengths even with changes in wire feed speed.

Implementation Method 1

a first sensor configured to sense a light intensity of the welding arc

Methodology Applied

Scientific EffectLight emission from welding arc: Electric Arc

Implementation Method 2

modifying the light intensity with respect to the current to determine a modified light intensity of the welding arc

Methodology Applied

Scientific EffectLight intensity modification based on current:

Data Source

PatentUS10065260B2System and method for controlling an arc welding process

Publication Date: 2018.09.04 ILLINOIS TOOL WORKS INC

AI summary

A welding system includes an electrode configured to be advanced toward a workpiece and a power supply configured to provide a flow of electricity to the electrode for generating a welding arc between the electrode and the workpiece. The welding system also includes a first sensor configured to sense a light intensity of the welding arc and a second sensor configured to sense a current provided to the electrode via the power supply. In addition, the welding system includes a controller communicatively coupled with the first and second sensors and configured to modify the light intensity with respect to the current. The controller is configured to control a welding parameter of the welding system based on the modified light intensity.