Robotic Pulse Arc Welding Control for Bird-Nesting Prevention
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Solution Overview
Problem
Pulsed arc welding systems, particularly in robotic applications, suffer from wire tangling ('bird nesting') that leads to damage of the welding gun/torch, especially with soft wires like aluminum, due to the wire stopping and melting at the contact tip, and excessive heating of other components.
Innovation Solution
A pulsed arc welding system with a controller that manages a series of welding output pulses, checks for electrical shorting, and shuts down if shorting is not confirmed within a set time to prevent damage, using feedback circuits for voltage and current monitoring, and adjusting wire feed speed during pulsed and short circuit phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pulsed arc welding is performed with soft wire (e.g., aluminum wire), then welding quality is improved, but wire tangling ('bird nesting') occurs more frequently causing welding gun damage
Solution Approach 1:
The system performs preliminary actions by generating a predetermined number of welding pulses before allowing the wire to feed freely. This controlled preliminary welding phase ensures the wire is properly positioned and reduces the likelihood of tangling before it can occur during free feeding.
Solution Approach 2:
The system uses feedback mechanisms to monitor welding parameters and detect wire feeding status. By continuously monitoring the welding process, the system can identify signs of wire tangling and adjust operations accordingly, preventing gun damage while maintaining weld quality.
2Productivity
If the wire feeder allows continuous wire feeding during pulsed welding, then productivity is improved, but the wire may stop feeding and melt at the contact tip causing excessive heating
Solution Approach 1:
The system implements periodic action by alternating between pulsed welding phases and free feeding phases. During pulsed phases, welding occurs at controlled intervals; during free feeding phases, the wire feeds without active welding. This periodic cycle prevents continuous overheating while maintaining high overall productivity.
Solution Approach 2:
The controller generates a predetermined number of welding pulses as a preliminary controlled action before transitioning to free feeding mode. This ensures that the wire is properly consumed and positioned before allowing unmonitored feeding, preventing accumulation of excess wire that could lead to tangling and overheating.
3Reliability
If the controller monitors wire feeding status continuously, then wire tangling detection is improved, but system complexity increases
Solution Approach 1:
The controller employs feedback mechanisms to monitor welding parameters such as voltage, current, and wire feed speed. By analyzing these feedback signals, the system can detect wire tangling conditions without requiring additional complex sensors or monitoring equipment, maintaining simplicity while improving reliability.
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
Prevents welding gun/torch damage by ensuring the welding wire electrically shorts to the workpiece, thereby avoiding melting and excessive heating, thus extending the system's lifespan and maintaining operational efficiency.
Implementation Method 1
generate and output a series of a determined number of welding output pulses to form an arc between the welding wire electrode and the workpiece
Implementation Method 2
allowing the welding wire electrode to continue to be fed toward the workpiece in an attempt to electrically short to the workpiece
Data Source
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AI summary
Embodiments of systems (100, 160) and methods related to pulsed arc welding are disclosed. A robotic welding system (160), having a welding torch (130) with a contact tip, is configured to perform the following method: (a) generate and output a series of a determined number (N) of welding output pulses as a welding wire electrode (E) is fed toward a workpiece (W); (b) stop generating welding output pulses while allowing the welding wire electrode (E) to continue to be fed toward the workpiece (W) in an attempt to electrically short to the workpiece (W); (c) attempt to confirm that the welding wire electrode (E) has electrically shorted to the workpiece (W) within a determined error time period (Terror); and (d) repeat steps (a) through (c) if electrical shorting of the welding wire electrode (E) has been confirmed within the determined error time period (Terror), else, shut down the robotic welding system (160) to avoid damaging the welding torch (130).