Variable Steering Ratio Bicycle Control for Stability

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Solution Overview

Problem

Existing bicycle safety systems do not adequately address the safety risks associated with excessive handlebar angle and steering angle during heavy braking, lifting of the rear wheel, and cornering, which can lead to accidents due to oversteering or tipping.

Innovation Solution

A method and device that detect rear wheel lifting and adjust the predetermined ratio between the handlebar angle and steering angle of the front wheel using sensors and an actuator, reducing the steering angle when the rear wheel lifts off to prevent falls and tipping, while also considering speed and handlebar angle changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the steering angle is increased to improve maneuverability during normal riding, then the handling responsiveness is improved, but the risk of oversteering and tipping increases during heavy braking or cornering

Engineering Contradiction:
Improvehandling responsivenessVSAvoidsafety during heavy braking
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the steering ratio variable rather than fixed. The actuator dynamically adjusts the steering ratio based on detected riding conditions (acceleration, handlebar angle, speed). During normal riding, a higher steering ratio provides responsive handling. During heavy braking or cornering, the system automatically reduces the steering ratio to limit front wheel rotation and prevent tipping, thus resolving the contradiction between handling responsiveness and safety.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the steering ratio parameter based on detected riding conditions. The control unit monitors acceleration, handlebar angle, and speed to determine when heavy braking or cornering is occurring. When these conditions are detected, the system adjusts the steering ratio parameter to a lower value, limiting the relationship between handlebar rotation and front wheel rotation. This parameter change prevents excessive steering input during critical maneuvers while maintaining normal steering characteristics during stable riding.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a fixed steering ratio is used to simplify the steering mechanism, then the device complexity is reduced, but the ability to adapt to different riding conditions is limited

Engineering Contradiction:
Improvesteering mechanism simplicityVSAvoidadaptation to riding conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent replaces a purely mechanical fixed-ratio steering system with an electronically controlled variable-ratio system. Sensors detect riding conditions (acceleration, handlebar angle, speed) and transmit data to a control unit. The control unit processes this information and commands an actuator to adjust the steering ratio accordingly. This substitution of mechanical simplicity with electronic control enables adaptation to different riding conditions while maintaining reasonable system complexity through integrated control electronics.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a universal steering system that can adapt to multiple riding conditions through a single integrated control system. The same sensor suite and control unit that monitor basic steering operations also detect heavy braking and cornering conditions. The actuator serves multiple functions by adjusting the steering ratio based on various detected conditions, making the system versatile across different riding scenarios without requiring separate mechanical systems for each condition.

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

Data Source

PatentEP3498580B1Method and device for adjusting a predetermined ratio between handlebar angle and steering angle of a front wheel of a bicycle
Publication Date: 2020.07.22 ROBERT BOSCH GMBH
  • EP3498580B1 patent drawingFigure 1
  • EP3498580B1 patent drawingFigure 2~3
  • EP3498580B1 patent drawingFigure 4

AI summary

The invention describes a method (90) for setting a predetermined ratio between the handlebar angle and the steering angle of a bicycle's front wheel. In a first method step, a lifting of the rear wheel is detected (40), and the predetermined ratio between the handlebar angle and the steering angle is then set based on the detected lifting of the rear wheel by means of an actuator (90) arranged on the bicycle's handlebars. The invention also describes a device designed to carry out the method according to the invention and a bicycle comprising the device.