Welding Robot Position Verification via Electrical Contact

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Solution Overview

Problem

Current methods for ensuring the correct positioning of a welding robot's head are inadequate, as they lack a reliable and efficient means to verify if the welding head reaches a predetermined position before starting a welding process, potentially leading to faulty operations.

Innovation Solution

A method involving a function check movement where the welding head is moved to a reference position, and a voltage is applied between the welding wire and a contact element to detect the potential difference and current flow, determining if the correct position is reached, with thresholds for differentiation between correct and incorrect positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a learning program with position detection is used to identify the actual position of the workpiece, then the positioning accuracy is improved, but the testing time and complexity increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidtesting time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the position detection function from the complex learning program and implements it as a separate, simplified functional test. A test contact element is provided that can be contacted by the welding wire to directly verify positioning accuracy without requiring the full learning program execution, thus reducing testing time while maintaining measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs a preliminary functional test before the actual welding operation. The welding head is moved to a test position and the positioning is verified using the test contact element and position detection program in advance, allowing the full learning program to be skipped or simplified, thereby reducing the overall testing time while ensuring positioning accuracy is confirmed beforehand.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the welding head is manually moved to position the welding wire relative to the workpiece, then the positioning accuracy is improved, but the automation level decreases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidautomation level
Core Design Contradiction:
Measurement precisionVSExtent of automation

Solution Approach 1:

The patent introduces a test contact element as an intermediary between the welding head and the workpiece. This intermediary element can be contacted by the welding wire to verify positioning accuracy. The system provides automated feedback through position detection and potential difference measurement, maintaining automation while enabling precise positioning verification similar to manual methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a verification system with test slot and catch funnel is used to ensure welding wire insertion, then the positioning reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvepositioning reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the welding head serve multiple functions: it performs both the actual welding operation and the functional positioning test. The welding wire itself is used both for welding and for contacting the test contact element to verify position. This eliminates the need for separate verification systems like test slots and catch funnels, reducing device complexity while maintaining positioning reliability through the automated position detection and electrical measurement.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Measurement precision

If the welding robot performs functional test movement to a reference position, then the positioning accuracy is improved, but the productivity decreases due to additional testing

Engineering Contradiction:
Improvepositioning accuracyVSAvoidproductivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs the functional test movement and position verification as a preliminary action before the actual welding production. The welding head is moved to a test reference position and the positioning is verified using the test contact element and position detection. Once verified, the full learning program can be skipped, and the actual welding operation can proceed immediately, ensuring positioning accuracy is confirmed beforehand without significantly impacting overall productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the essential position verification function from the time-consuming full learning program and implementation cycle. By providing a separate, simplified functional test that checks positioning accuracy independently, the system allows the main welding operation to proceed without repeating the entire learning process, thus maintaining positioning accuracy while improving productivity.

Inventive Principle:
Principle #2Taking out (Extraction)

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 method allows for a simple and effective verification of the welding head's position, preventing faulty operations by generating an enable or error message based on the detected electrical parameters, ensuring the robot is correctly positioned before starting work.

Implementation Method 1

When the welding head (14) is positioned in the functional test reference position, the welding wire (16) leading out of the welding head (14) touches a reference contact area (18) of a functional test contact element (20}, ensuring that an electrically conductive connection is established between the welding head or the welding wire leading out of it and the functional test contact element

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3406384B1Method for verification of the position of a welding robot
Publication Date: 2020.07.29 EBERSPACHER EXHAUST TECH WILSDRUFF GMBH
  • EP3406384B1 patent drawingFigure 1~2

AI summary

A method for functionally verifying a welding robot comprises the following measures: a) performing a functional verification movement of a welding head (14) of a welding robot (10) to move the welding head (14) into a functional verification reference position, b) after performing the functional verification movement, applying a functional verification voltage between the welding head (14) and a functional verification contact element (20), c) detecting a potential difference built up between the welding head (14) and the functional verification contact element (20) and/or a current flow between the welding head (14) and the functional verification contact element (20), d) based on the potential difference detected in measure c), determining whether the welding head (14) is in the functional verification reference position.