Multi-Robot Stringer Joining for Precise Adhesive Positioning

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Solution Overview

Problem

Current joining technologies in aircraft and vehicle construction, such as robot-guided tools, face limitations in positioning accuracy, process reliability, and flexibility when attaching elongated components like stringers to flexible surface structures, particularly in creating precise and reproducible adhesive connections.

Innovation Solution

A joining tool and method that employs multiple industrial robots with a gripper, counterholder, and heating device to precisely position and align components, allowing for simultaneous joining at multiple discrete points along the component's length, with controlled force and heat application, enabling flexible adaptation to varying component contours and workpiece shapes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a rolling joining tool is used to join components to workpieces, then the joining process can be automated and continuous motion is achieved, but positioning accuracy and the ability to create precise adhesive connections deteriorate

Engineering Contradiction:
Improveautomation of joining processVSAvoidpositioning accuracy
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The continuous joining process is segmented into discrete joining points along the component length. The joining tool moves to specific predetermined locations and performs joining operations at each point sequentially or simultaneously, rather than attempting continuous joining. This segmentation allows precise positioning at each discrete point while maintaining automated operation through robot control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The joining tool incorporates movable elements including the heating device that can extend and retract, and the gripper that can adjust its position. These dynamic components allow the tool to adapt to varying component contours and maintain precise positioning accuracy at each joining point while moving between locations automatically.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If discrete joining points are used instead of continuous joining, then positioning accuracy and adhesive bond quality improve, but the number of joining operations and time required increase

Engineering Contradiction:
Improveadhesive bond qualityVSAvoidjoining speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

Multiple joining operations are merged into simultaneous execution. The joining tool is equipped with multiple heating devices and grippers that can perform joining operations at multiple discrete points simultaneously, rather than sequentially. This combines the precision of discrete point joining with the productivity of parallel processing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The joining process maintains continuity through automated robot movement between discrete joining points. While the actual adhesive application and heating occur at discrete points, the robot moves continuously between points without interruption, and multiple points are processed in parallel, maintaining overall process continuity and high productivity.

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If multiple industrial robots with joining tools are used, then positioning accuracy and process reliability improve, but device complexity and cost increase

Engineering Contradiction:
Improveprocess reliabilityVSAvoidnumber of robots and tools
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each joining tool is designed as a multi-functional unit that integrates gripping, positioning, heating, and pressing capabilities. The same tool can perform multiple operations at different joining points, reducing the need for separate specialized devices and simplifying the overall system while maintaining high reliability through consistent multi-functional performance.

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

4Strength

If the joining tool applies force and heat simultaneously at discrete points, then adhesive bond strength and quality improve, but the complexity of controlling force and temperature increases

Engineering Contradiction:
Improveadhesive bond strengthVSAvoidcontrol system complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The joining tool incorporates sensors that provide feedback on force application and temperature at each joining point. This feedback is used by the control system to automatically adjust parameters in real-time, ensuring consistent adhesive bond quality without requiring complex manual control. The feedback loop simplifies the control task by providing real-time data for automatic parameter adjustment.

Inventive Principle:
Principle #23Feedback

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 enhances positioning accuracy, process reliability, and flexibility, allowing for faster and more cost-effective joining with improved quality and reproducibility of the joint connections, suitable for components of any length and complex shapes.

Implementation Method 1

the component and the workpiece are heated in the joining area

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The component is held by a suction gripper

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3113915B1Joining tool, joining device and joining method
Publication Date: 2023.09.13 KUKA SYSTEMS GMBH
  • EP3113915B1 patent drawingFigure 1
  • EP3113915B1 patent drawingFigure 2
  • EP3113915B1 patent drawingFigure 3

AI summary

The invention relates to a joining tool (7), a joining device (2) equipped therewith and a joining method for joining stringers (9) to flexible workpieces (8). A plurality of industrial robots (3 to 6) are equipped with joining tools (7) and handle and join the stringer (9) jointly. The joining tools (7) are heated and grip the stringer (9) by means of a gripper tool (25) on the upper face (30) of the structural unit, using a controlled suction gripper (26), a heated counter-holder (29), which is arranged next to the gripper tool, likewise acting upon the upper face (30) of the structural unit.