Robot Welding Path Control for Continuous Corner Bead Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional robot control methods are limited to linear welding and cannot achieve continuous processing along bent processing lines, such as an L-shaped line, resulting in low work efficiency and an inability to achieve a desired bead shape at bent portions.
Innovation Solution
A robot control method that modifies welding points in real-time using a sensor-mounted laser sensor to detect the shape of the workpiece, allowing the welding torch to change its attitude and continue welding without stopping, even at corners, by generating abnormality decision points and modifying interpolation points based on detected displacements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional robot control method is used for linear welding, then welding can be performed along straight lines, but continuous welding along bent processing lines cannot be achieved
Solution Approach 1:
The patent applies dynamics by making the welding torch attitude changeable during the welding process. The control method dynamically adjusts the torch orientation based on the bending angle of the processing line, allowing continuous welding along bent paths. The torch attitude is modified in real-time according to the detected workpiece shape and the predefined bending angle information, enabling adaptation to curved trajectories without stopping the welding process.
Solution Approach 2:
The patent applies preliminary action by pre-storing the bending angle information of the processing line before welding begins. The control method uses this pre-defined geometric information about the bent path to proactively adjust the torch attitude during welding, rather than reacting after deviations occur. This allows the system to anticipate and compensate for the bent path geometry in advance.
2Manufacturing precision
If welding is performed in multiple steps along bent lines, then each linear segment can be welded separately, but continuous processing cannot be achieved and work efficiency decreases
Solution Approach 1:
The patent applies continuity of useful action by enabling uninterrupted welding along bent processing lines. The control method maintains continuous welding operation by dynamically adjusting the torch attitude to follow the bent path. The welding process does not need to stop at corners or bent portions, as the torch orientation is continuously adapted to match the processing line geometry, ensuring both quality and efficiency.
3Measurement precision
If laser sensor detects workpiece shape in real-time, then welding points can be modified dynamically, but the torch attitude cannot be adjusted for bent lines
Solution Approach 1:
The patent applies feedback by using the laser sensor to detect the actual workpiece shape during welding and comparing it with the expected geometry. The control method uses this real-time shape information as feedback to dynamically adjust both the welding points and the torch attitude. The detected shape deviations are fed back to the control system, which modifies the torch orientation to compensate for variations in the bent processing line.
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
Enables continuous processing along bent lines, improving work efficiency and achieving a required finish by dynamically adjusting the welding trajectory to account for shape changes and thermal strains during welding.
Implementation Method 1
a sensor for recognizing the shape of workpiece is further mounted on a work tool attached to a tip of the robot
Implementation Method 2
Laser sensor 403 recognizes a point where the shape of workpiece W changes
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A robot control method includes a teaching step, first processing step, modifying step, second processing step, and third processing step. In the modifying step, a third teaching point is changed to a second modified point, a fourth teaching point to a third modified point, and a fifth teaching point to a fourth modified point, based on a difference between a second teaching point and a first modified point. A profile modifying control to change the position of a work tool is applied, using a sensor mounted on the processing advancing direction side of the work tool, in the first processing step and the third processing step. An attitude of the work tool is changed during the second processing step.