Robot Welding Control for Part Geometry and Gap Variation
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Solution Overview
Problem
Automated welding systems for motor vehicles face challenges in achieving consistent welds due to variations in part geometry, clamping, and transient distortions, which affect the quality of gas metal arc welding.
Innovation Solution
A method and system for intelligent robot-based welding that adjusts process variables in real-time based on geometrical measurements of workpieces, using a controller with a vision sensor and laser projector to monitor and adjust parameters such as robot path, weld speed, and weld current, ensuring weld quality and repairing welds as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional gas metal arc welding is used with fixed process variables, then the welding process is simple and fast, but weld quality is inconsistent due to part variations, clamping, and transient distortions
Solution Approach 1:
The welding system transitions from static, predetermined process variables to dynamic, real-time adjusted parameters. Sensors continuously monitor workpiece geometry, gap, and position, while the controller dynamically modifies welding parameters (current, voltage, speed, torch angle) during the welding process to compensate for variations and maintain consistent weld quality.
Solution Approach 2:
The system implements closed-loop feedback control where sensors detect workpiece geometry, gap, and position in real-time, the controller processes this information, and adjusts welding parameters accordingly. This feedback mechanism enables the system to respond to part variations, clamping effects, and transient distortions, ensuring consistent weld quality despite changing conditions.
2Manufacturing precision
If real-time adjustment of process variables is implemented, then weld quality improves, but the welding process becomes more complex and time-consuming
Solution Approach 1:
The system performs sensing, processing, and parameter adjustment continuously throughout the welding process without interrupting the welding operation. Multiple sensors operate simultaneously to monitor various parameters, and the controller continuously updates welding parameters in real-time, ensuring that the useful action of welding proceeds without interruption while maintaining quality.
Solution Approach 2:
The system replaces manual measurement and adjustment operations with automated sensing and control systems. Optical sensors, laser scanners, and position sensors automatically detect workpiece geometry and position, while the controller automatically adjusts welding parameters, eliminating the need for manual intervention and maintaining high welding speed.
3Measurement precision
If multiple sensors and real-time monitoring are added, then measurement precision improves, but device complexity increases
Solution Approach 1:
The welding system integrates multiple sensors and measurement devices that serve multiple functions. For example, the vision system not only measures workpiece geometry but also tracks position and orientation. The laser scanner simultaneously measures gap and surface topology. This multi-functionality reduces the need for separate dedicated sensors for each measurement type, managing system complexity while maintaining high measurement precision.
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 results in improved weld quality by continuously monitoring and adjusting welding parameters, reducing discrepancies and distortions, and enhancing the overall consistency of the welding process.
Implementation Method 1
a vision sensor disposed on and in communication with the robot and the controller for sensing geometric location of the first and second workpieces
Implementation Method 2
a laser projector disposed on and in communication with the robot to project a laser on the first and second workpieces for sensing a gap between the first and second workpieces
Implementation Method 3
In gas metal arc welding, a sound weld is affected by the location of substrates to be welded along with the gap therebetween
Implementation Method 4
Automotive sheet metal and structural welding is a fabrication process that joins components by using heat to melt the material of components and allowing them to cool and fuse together
Data Source
AI summary
A system and method of enhanced automated welding of a first workpiece and a second workpiece are provided. The method comprises providing a system for intelligent robot-based welding of the first workpiece and the second workpiece. The method further comprises determining a geometrical location of the first workpiece and the second workpiece to be welded at a welding sequence based a predetermined process variable. The method further comprises adjusting the predetermined process variable based on the geometrical location of the first and second workpieces to define an actual process variable. The method further comprises welding a first portion of the first and second workpieces with the actual process variable to define a first welded portion. The method further comprises determining a weld quality of the first welded portion.