Modular Wheelchair Leg Modules with Selective Drive Modes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional wheelchairs are not adaptable to changing environmental obstacles such as steps, terrain, and tight spaces, limiting their maneuverability and efficiency in daily use.

Innovation Solution

A wheelchair system with modular leg modules that include upper and lower leg assemblies, featuring omni-directional wheels and a control device to transition between front-wheel drive, mid-wheel drive, and omni-drive modes, allowing for improved maneuverability and adaptability to various terrains and obstacles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional wheelchairs use fixed wheel configurations, then the structure is simple and easy to manufacture, but the adaptability to changing environmental obstacles is poor

Engineering Contradiction:
Improveadaptability to environmental obstaclesVSAvoidwheelchair structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The wheelchair is divided into modular leg assemblies, each containing independent wheel units that can be selectively positioned. The leg assembly includes an upper leg portion with a first wheel and a lower leg portion with a second wheel, allowing independent control of each wheel's position and function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wheelchair transitions from a static fixed configuration to a dynamic reconfigurable system. The leg assemblies can be selectively positioned between elevated and lowered states, and wheels can be selectively driven based on operational mode, enabling real-time adaptation to different terrains and obstacles.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If multiple drive modes are implemented, then the maneuverability and terrain capability are improved, but the control system complexity increases

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The same leg assembly and wheel structure serve multiple functions across different drive modes. The first and second wheels can alternatively be positioned as drive wheels, steering wheels, or idle wheels, allowing a single mechanical structure to perform multiple roles depending on the selected operational mode.

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

Solution Approach 2:

The control system dynamically reconfigures the wheelchair's operational characteristics by selectively activating different wheel combinations for driving and steering functions. This allows the system to adapt its maneuverability and terrain capability based on environmental conditions without requiring physically separate systems for each mode.

Inventive Principle:
Principle #15Dynamics

3Reliability

If wheels are selectively positioned and driven, then the stability and mobility in different terrains are improved, but the mechanical complexity of the positioning mechanism increases

Engineering Contradiction:
Improvestability in different terrainsVSAvoidpositioning mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The positioning mechanism is segmented into modular leg assemblies with independent upper and lower leg portions. Each leg assembly can be independently controlled to position its wheels in elevated or lowered states, allowing selective ground contact and stable configuration adaptation to different terrain conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the positional parameters of the wheels relative to the ground by elevating or lowering leg assemblies. This parameter adjustment allows the wheelchair to maintain stable contact with various terrain surfaces and selectively engage different wheels for optimal mobility and stability in different environmental conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3689314B1Modular power base arrangement
Publication Date: 2023.04.05 TOYOTA MOTOR NORTH AMERICA INC
  • EP3689314B1 patent drawingFigure 1A
  • EP3689314B1 patent drawingFigure 1B
  • EP3689314B1 patent drawingFigure 2A~2B

AI summary

A wheelchair assembly including a control device, a power base, and a plurality of leg modules coupled to the power base is disclosed. Each of a first, a second, and a third leg module may include an upper leg assembly and a lower leg assembly. Each lower leg assembly may include a knee joint and a foot joint and each lower leg assembly may rotatably couple to each upper leg assembly at the knee joint. A knee wheel located at the knee joint of each lower leg assembly, may include an omni-directional wheel, and may be selectively drivable. A foot wheel located at the foot joint of each lower leg assembly may be selectively drivable. The control device, based on a selectable mode of operation, may selectively position at least one of the knee wheel or the foot wheel associated with each respective leg module relative to a surface.