Welding Torch CTWD Signal Referencing for Seam Tracking Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional welding systems require repeated reference runs to adjust to changes in welding characteristics and are prone to errors due to incorrect workpiece clamping, necessitating a method for providing a referenced distance signal that maintains a consistent seamtrack signal without additional reference movements.
Innovation Solution
A method and device that set an operating point defined by wire feed speed, welding voltage, and CTWD distance, measuring current parameters, adjusting actual parameter values based on deviations, and outputting a referenced distance signal to a robot control unit to maintain a desired CTWD distance, allowing for real-time adjustments to welding parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional seamtrack control is used with reference runs, then the welding torch position can be controlled, but repeated reference runs are required when welding characteristics change
Solution Approach 1:
The system continuously monitors welding parameters (current, voltage, wire feed speed) and uses feedback loops to dynamically adjust the seamtrack signal. This real-time feedback mechanism eliminates the need for repeated reference runs by automatically compensating for changes in welding characteristics through parameter deviation detection and correction.
Solution Approach 2:
The welding system performs self-calibration by automatically detecting parameter deviations from stored reference values and adjusting its own operation accordingly. The control unit continuously compares actual welding parameters with stored reference data and autonomously corrects seamtrack positioning without requiring external reference runs or manual intervention.
2Measurement precision
If conventional reference runs are performed, then seamtrack signal can be established, but errors occur due to incorrect workpiece clamping
Solution Approach 1:
The system employs continuous feedback monitoring of welding parameters during the welding process. By comparing real-time measurements against stored reference values, the system can detect deviations caused by incorrect clamping or positioning and automatically compensate, thereby maintaining measurement precision without requiring perfect initial setup.
Solution Approach 2:
The system stores reference welding parameters and characteristic data before the actual welding process begins. These pre-stored reference values serve as a baseline for continuous comparison during welding, allowing the system to detect and correct deviations caused by setup errors without requiring re-clamping or re-positioning of the workpiece.
3Manufacturing precision
If welding parameters are adjusted to compensate for clamping errors, then weld quality can be maintained, but the referenced distance signal becomes inaccurate
Solution Approach 1:
The system uses feedback control to distinguish between parameter changes that are compensations for positioning errors and those that represent actual welding characteristic changes. By continuously monitoring multiple parameters simultaneously and analyzing their deviations from reference values, the system can maintain accurate referenced distance signals while still compensating for clamping errors through controlled parameter adjustments.
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 welding with adaptive control, maintaining a consistent weld quality by automatically adjusting welding parameters in response to changes, eliminating the need for repeated reference runs and reducing errors caused by incorrect clamping.
Implementation Method 1
an arc being produced during the welding process between the tip of the welding wire electrode and the workpiece to be machined
Implementation Method 2
the welding wire electrode melting off at its tip during the welding process
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method and apparatus for providing a referenced distance signal (d), which corresponds to the distance between a contact tip (KS) of a welding torch and a workpiece (W) to be machined, said method having the steps of adjusting (S1) a working point (AP) on a predefined characteristic welding line (SKL) which is defined at least by a wire feed rate (VD), a welding voltage (U), and/or a welding current (I), and adjusting a CTWD distance between a contact tip (KS) of the welding torch and the workpiece (W) to be machined; reading or determining (S2) a parameter setpoint value (PSoll) of at least one CTWD distance-dependent parameter (P) for the adjusted working point (AP) on the characteristic welding line (SKL); determining (S3) a parameter actual value (Pist) of the CTWD distance-dependent parameter (P) by measuring at least one of the actual welding parameters (P), in particular wire feed rate (VD), weld voltage (U) and/or welding current (I); adapting (S4) the determined parameter actual value (Pist) depending on a deviation (ΔΡ) between the parameter setpoint value (PSoll) and a reference value (Pref); and outputting (S5) the referenced distance signal (d), which corresponds to the adapted parameter actual value (Pist'), to a position or location controller of a robot arm.