Wire-Driven Manipulator Guide Structure for Reproducible Bending

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Solution Overview

Problem

The flexible members in existing endoscope manipulators slide frictionally with respect to spacer members, leading to shifts in relative positions and impairing driving reproducibility, which affects the accuracy of controlling the manipulator's posture.

Innovation Solution

A wire-driven manipulator design where flexible members are fixed to spacer members through adhesion, pinning, or screwing, and guided by members with low friction, ensuring consistent relative positions and improved control accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If flexible members slide frictionally with respect to spacer members, then the structure allows movement and bending, but the relative positions shift and driving reproducibility deteriorates

Engineering Contradiction:
Improvebending capabilityVSAvoiddriving reproducibility
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A guide member is introduced as an intermediary component between the flexible member and spacer member. The guide member has a guide hole through which the flexible member passes, constraining the flexible member's movement path while allowing sliding. This intermediary structure prevents lateral displacement and maintains consistent relative positions, improving driving reproducibility without compromising bending capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The manipulator is divided into discrete segments (spacer members) along its length, with each segment containing a guide member. This segmentation allows the flexible member to slide within controlled intervals while maintaining overall structural integrity and positional consistency across multiple segments

Inventive Principle:
Principle #1Segmentation

2Reliability

If flexible members are fixed to spacer members, then driving reproducibility improves, but the manipulator loses flexibility and bending capability

Engineering Contradiction:
Improvedriving reproducibilityVSAvoidbending flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The guide member creates a dynamic constraint system where the flexible member is guided but not fixed. The guide hole provides lateral constraint while allowing axial sliding motion, enabling the system to adapt its degree of freedom based on operational needs - maintaining positional consistency during operation while preserving bending capability

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If guide members with low friction are used, then driving accuracy improves, but manufacturing complexity increases

Engineering Contradiction:
Improvecontrol accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The guide member is designed as a simple, easily manufacturable component that can be produced through conventional machining processes. The guide hole can be drilled and reamed to standard tolerances, and the component can be made from common materials like aluminum or steel, keeping manufacturing costs low while achieving the required guidance precision

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP3589183B1Wire-driven manipulator
Publication Date: 2025.11.12 CANON KK
  • EP3589183B1 patent drawingFigure 1A~1B
  • EP3589183B1 patent drawingFigure 2
  • EP3589183B1 patent drawingFigure 3A~3B

AI summary

A wire-driven manipulator includes a plurality of flexible members, a drive unit configured to drive the plurality of flexible members, and at least one bendable portion including a distal end member and at least one guide member disposed nearer to the drive unit than the distal end member. The bendable portion is configured to be bent by driving the plurality of flexible members. The plurality of flexible members are connected to the distal end member. At least one of the plurality of flexible members is also connected to the guide member. The other of the plurality of flexible members is configured to be slidable with respect to the guide member.