Multi-Axis Roller End Effector for Misalignment-Tolerant Capture

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Solution Overview

Problem

Existing capture devices for hovering aircraft and similar objects are not adaptable to multi-axis misalignment, require precise alignment, and are costly and complex, posing risks of damage due to misalignment and operational challenges in adverse conditions.

Innovation Solution

End effectors with multiple roller wheels arranged in non-parallel planes and axes, capable of capturing and releasing objects via passive receptacles, allowing for 360-degree approach angles and tolerating positional and rotational misalignment, with modular design for different applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional articulated robotic grippers are used to capture hovering aircraft, then capture capability is achieved, but the system becomes complex and expensive requiring high-speed vision systems and precise alignment

Engineering Contradiction:
Improvecapture capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The end effector is segmented into multiple independent roller wheels (at least two) that can rotate independently about different axes. This segmentation allows each roller wheel to independently accommodate misalignment in different directions, eliminating the need for complex vision systems and precise alignment mechanisms while maintaining reliable capture capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The roller wheel configuration provides universal capture capability that tolerates misalignment in multiple degrees of freedom. The same simple mechanical structure handles both positional and rotational misalignment, replacing the need for separate complex alignment and capture systems

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

2Measurement precision

If precise alignment is required for gripper capture, then capture accuracy is improved, but error tolerance is reduced and damage risk increases

Engineering Contradiction:
Improvecapture accuracyVSAvoiderror tolerance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system changes the geometric parameters of the end effector by configuring roller wheels at different orientations and positions. This geometric configuration allows the capture mechanism to accommodate a range of misalignment parameters (positional and rotational offsets) while maintaining capture accuracy, thereby increasing error tolerance without sacrificing precision

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If high-speed vision systems and precise localization are used, then alignment precision is improved, but cost and maintenance difficulty increase

Engineering Contradiction:
Improvealignment precisionVSAvoidmaintenance difficulty
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The roller wheel-based end effector is self-aligning through its mechanical geometry. The configuration of rollers at different orientations automatically accommodates misalignment without requiring external vision systems or complex localization equipment, making the system simpler to manufacture, operate, and maintain in field conditions

Inventive Principle:
Principle #25Self-service

4Device complexity

If limited range of approach angles is used, then gripper simplicity is maintained, but adaptability to hovering aircraft is reduced

Engineering Contradiction:
Improvegripper simplicityVSAvoidapproach angle range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The end effector extends capture capability into multiple dimensional spaces by configuring roller wheels to rotate about different axes (including vertical and horizontal axes). This multi-axis configuration allows the simple roller wheel mechanism to accommodate approach angles from any direction in three-dimensional space, greatly increasing adaptability while maintaining mechanical simplicity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4197921B1End effectors with multi-axis roller wheels, systems including the same, and related methods
Publication Date: 2025.11.19 THE BOEING CO
  • EP4197921B1 patent drawingFigure 1
  • EP4197921B1 patent drawingFigure 2
  • EP4197921B1 patent drawingFigure 3~6

AI summary

End effectors and systems may capture, release, and/or create a mating engagement between the end effector and a target object. Said end effectors are tolerant of positional and rotational misalignment of the target object, and include a plurality of roller wheels (14, 16, 18), one or more of which is arranged in a non-parallel plane with respect to one or more other roller wheels (14, 16, 18). A first roller wheel (14) configured to rotate in a first plane (118), a second roller wheel (16) configured to rotate in a second plane (120), and a third roller wheel (18) configured to rotate in a third plane (122) may be arranged such that the end effector (10) is configured to engage a passive receptacle of the target object, to capture the target object. Rotating the roller wheels in the opposite direction may cause the target object to be released or launched, by urging the passive receptacle off of or away from the roller wheels.