Passive Walking Module With Crank-Coupled Leg Coordination

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Solution Overview

Problem

Conventional passive walking apparatuses lack a mechanism for coordinated operation of their legs, making it difficult to maintain stable walking.

Innovation Solution

A passive walking apparatus with a hip portion, two legs, and a crank mechanism where the movement of one leg is converted into the movement of the other leg through a crankshaft, allowing for coordinated and stable walking by pivoting the crank portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a passive walking apparatus includes two legs and a hip joint portion without a coordination mechanism, then the structure is simple, but the legs cannot operate in coordination making stable walking difficult

Engineering Contradiction:
Improvestable walkingVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A crank mechanism is introduced as an intermediary component between the two legs. The crank mechanism includes a crankshaft with first and second crank portions that convert the motion of one leg into coordinated motion of the other leg, enabling stable walking without complex control systems

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The crank mechanism dynamically converts the rearward movement of one leg into forward movement of the other leg through rotating crank portions. This dynamic transformation allows the legs to operate in coordination automatically based on the walking motion itself

Inventive Principle:
Principle #15Dynamics

2Reliability

If the crank mechanism is added to coordinate leg movement, then stable walking is achieved, but the device complexity increases

Engineering Contradiction:
Improvecontinuous passive walkingVSAvoidcrank mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The crank mechanism merges the motion of both legs into a unified system through the crankshaft. The first and second crank portions are combined on a single crankshaft, allowing coordinated operation while maintaining a compact and relatively simple overall structure

Inventive Principle:
Principle #5Merging (Combining)

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

Enables continuous stable passive walking by converting the rearward movement of one leg into forward movement of the other leg, ensuring consistent progression.

Implementation Method 1

a crank mechanism including a first-leg-side crank portion provided on a side of the first side portion, a second-leg-side crank portion provided on a side of the second side portion as being opposite in phase to the first-leg-side crank portion, a crankshaft coupling the first-leg-side crank portion and the second-leg-side crank portion to each other

Methodology Applied
Scientific EffectCrank mechanism: Crankshaft

Implementation Method 2

a first-leg-side connection portion connected to the first leg and the first-leg-side crank portion, and a second-leg-side connection portion connected to the second-leg-side crank portion and the second leg

Methodology Applied
Scientific EffectMechanical coupling: Mechanical Force

Data Source

PatentEP3450115B1Passive walking device and passive walking module
Publication Date: 2021.03.31 NINTENDO CO LTD
  • EP3450115B1 patent drawingFigure 1
  • EP3450115B1 patent drawingFigure 2
  • EP3450115B1 patent drawingFigure 3

AI summary

A passive walking apparatus (100) according to one embodiment includes a hip portion (1), a first leg (21), a second leg (22), and a crank mechanism (3) including a first-leg-side crank portion (31), a second-leg-side crank portion (34), a crankshaft (33), a first-leg-side connection portion (32), and a second-leg-side connection portion (35). When the first leg (21) moves rearward from the front relatively to the hip portion (1) as being in contact with a walking surface (GR), the first-leg-side connection portion (32) has the first-leg-side crank portion (31) pivot, the first-leg-side crank portion (31) has the second-leg-side crank portion (34) pivot around the crankshaft (33), and the second-leg-side crank portion (34) moves the second leg (22) forward from the rear relatively to the hip portion (1) with the second-leg-side connection portion (35) being interposed.