Tactile Key Height and Shape for Driver Morphology Adaptation

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Solution Overview

Problem

The existing tactile key in railway vehicle driving manipulators is not suitable for all driver morphologies, leading to difficulty in activation and deactivation, causing physical fatigue and musculoskeletal disorders due to unnatural thumb positioning.

Innovation Solution

A tactile key with a significant height extending over all possible hand widths, positioned between 60mm and 95mm, and an elliptical shape extending along the major axis, ensuring the thumb is opposite the key regardless of morphology, reducing the need for unnatural thumb movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a small localized tactile key is used on the manipulator, then the control device is compact and ergonomic for the manipulator structure, but the key becomes difficult to reach for drivers with certain hand morphologies, causing unnatural thumb positioning and physical fatigue

Engineering Contradiction:
Improveease of key activationVSAvoidadaptability to different hand morphologies
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent changes the key's dimensional parameters, specifically increasing its height from a small localized size to a significant height of 60-95mm, and modifies its shape to an elliptical form extending along the major axis. This parameter change allows the key to accommodate various hand widths and thumb positions, making it accessible to drivers with different hand morphologies without requiring unnatural positioning

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from a small two-dimensional localized key to a three-dimensional extended key structure with significant height (60-95mm) along the vertical axis. This dimensional expansion creates a larger target area that can be reached by thumbs at different heights, effectively solving the accessibility problem for various hand morphologies

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

2Device complexity

If the tactile key is positioned at a fixed location on the handle, then the manipulator structure is simple, but the key may not be facing the driver's thumb for all hand morphologies, requiring unnatural thumb extension or movement

Engineering Contradiction:
Improvesimplicity of manipulator structureVSAvoidnatural thumb positioning
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent modifies the key's height parameter to 60-95mm and its shape to an elliptical form, creating a structure that naturally accommodates various thumb positions. This allows the key to be effectively positioned at multiple heights simultaneously, eliminating the need for complex adjustable mechanisms while maintaining natural thumb positioning for diverse hand morphologies

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If a small diameter circular key is used, then the key occupies minimal space on the handle, but the reduced surface area makes it difficult to activate for drivers with larger hand widths

Engineering Contradiction:
Improvekey surface areaVSAvoidcompatibility with all hand morphologies
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent fundamentally changes the key's dimensional parameters, increasing its height to 60-95mm and shaping it as an ellipse extending along the major axis. This creates a vertically elongated key surface that can accommodate various hand widths, allowing drivers with different morphologies to naturally contact the key with their thumbs without requiring excessive hand or thumb movement

Inventive Principle:
Principle #35Parameter changes

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

The solution allows for easy and natural activation of the automatic standby control, reducing physical and mental fatigue across various hand morphologies, ensuring the thumb can activate the key without effort, thus minimizing fatigue and improving ergonomics.

Implementation Method 1

a tactile key electrically connected to the automatic standby processing device by maintaining pressure control

Methodology Applied
Scientific EffectCapacitive sensing: Capacitance

Data Source

PatentEP2492938B1Drive controller including a touch-sensitive button
Publication Date: 2018.04.04 ALSTOM TRANSPORT TECH SAS
  • EP2492938B1 patent drawingFigure 1~2
  • EP2492938B1 patent drawingFigure 3~4
  • EP2492938B1 patent drawingFigure 5

AI summary

The controller (1) has a handle (8) including a touch-sensitive button (20) electrically connected to a dead man's switch processing device (30) by maintenance support control functions. The button is located on a side face (18) of the handle. The button extends between a lower edge (22) arranged at a height (Hinf) separating a support element (2) and the lower edge, where the height is in range of 52 mm and 82 mm and an upper edge (24) arranged at a height (hsup) separating the support element and the upper edge, where the height is in range of 88 mm and 118 mm.