Dual-Robot Welding Path Correction for Corners and Curves

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Solution Overview

Problem

Existing hybrid laser welding systems face challenges in reaching internal corners and precisely following curved paths due to the size and fixed alignment of laser and arc welding devices, limiting their reachability and adaptability.

Innovation Solution

A method using two robots with separate welding heads, where a joint detection device reads welding joint characteristics to correct trajectories for both laser and arc welding devices, allowing for improved reachability and adaptability by adjusting the timing of the welding paths based on the distance between the devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If both laser welding device and arc welding device are mounted together on a single robot, then the system achieves integrated welding capability, but the size of the assembly makes it difficult to reach internal corners of welded assemblies

Engineering Contradiction:
Improveintegrated welding capabilityVSAvoidreachability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent divides the welding system into two separate robots, each carrying one welding device (laser or arc). This segmentation allows each robot to independently access different areas of the workpiece, including internal corners, while maintaining the integrated welding capability through coordinated operation of both robots and devices.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If joint detection device, laser welding device and arc welding device are fixedly aligned, then the system structure is simplified, but it becomes impossible to precisely follow a curve, whether internal or external

Engineering Contradiction:
Improvesystem structureVSAvoidcurve following precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent makes the welding devices dynamic by mounting them on separate robotic manipulators that can independently move and position themselves. This allows the laser and arc welding devices to follow curved trajectories precisely by coordinating their movements, while the joint detection device remains fixed or moves independently to detect joint characteristics.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the joint detection device is fixedly installed, then the device structure is simplified, but the system cannot adapt to varying welding joint characteristics along the welding path

Engineering Contradiction:
Improvedevice structureVSAvoidreal-time adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements feedback by using the joint detection device to read welding joint characteristics (such as gap size, joint type) along the welding path and using this information to correct the welding trajectories in real-time. The controller adjusts the paths of both welding devices based on the detected characteristics, enabling adaptation to varying joint conditions while maintaining a relatively simple device structure.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3119552B1Method of welding components along a welding joint using two robots
Publication Date: 2021.01.27 BOMBARDIER TRANSPORTATION GMBH
  • EP3119552B1 patent drawingFigure 1
  • EP3119552B1 patent drawingFigure 2
  • EP3119552B1 patent drawingFigure 3

AI summary

A welding system comprises a two manipulators and a controller. A first manipulator has a joint detection device and a first welding device, usually of the laser type while the second manipulator has a second welding device, usually of the arc weld type. The joint detection device is operative to read welding joint characteristics along a welding joint. The controller determines a corrected trajectory based on a predetermined welding trajectory and on the welding joint characteristics read by the joint detection device. This corrected trajectory is transmitted with a first time delay to the first manipulator and with a second time delay to the second manipulator. The second time delay is a function of a distance between the joint detection device and the second welding device. A corresponding method for welding components along a welding joint is also disclosed.