Motorized Assist Bicycle Controller for Power Range Trade-off

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Solution Overview

Problem

Conventional electrically assisted bicycles face usability issues due to differences in rider strength and changing road conditions, leading to inappropriate generation or cessation of assistive power, affecting traveling range and power usage.

Innovation Solution

An electrically assisted bicycle with a motor controller that adjusts operation modes based on set actuating conditions for generating and stopping assistive power, allowing for multiple power consumption settings and automatic or manual shifting between them, enabling optimal power usage based on pedal effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the assistive power is stopped when pedal effort is smaller than a constant threshold to increase traveling range, then the traveling range per charging is improved, but the usability deteriorates because the constant threshold cannot adapt to different rider strengths or sudden road condition changes

Engineering Contradiction:
Improvetraveling rangeVSAvoidusability
Core Design Contradiction:
Duration of action of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the threshold value changeable rather than fixed. The motor controller allows the threshold for stopping assistive power to be dynamically adjusted based on rider selection or automatic detection of riding conditions, enabling adaptation to different rider strengths and road conditions while maintaining the ability to extend traveling range when appropriate

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the assistive power is generated with a constant threshold to ensure sufficient power for all riders, then the usability is improved, but the traveling range per charging decreases due to excessive power consumption

Engineering Contradiction:
ImproveusabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by allowing the threshold value to be changed between different settings. The system can switch between a lower threshold (for extended range) and a higher threshold (for more assistive power), or automatically adjust the threshold parameter based on detected riding conditions, thus optimizing the balance between power consumption and rider assistance needs

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1967446B1Motorized assist bicycle
Publication Date: 2014.02.26 YAMAHA MOTOR CO LTD
  • EP1967446B1 patent drawingFigure 1
  • EP1967446B1 patent drawingFigure 2
  • EP1967446B1 patent drawingFigure 3

AI summary

A motor (3) is provided for generating assistive power according to a pedal effort. A motor controller (1) is provided for controlling operation of the motor (3) based on an actuating condition for generating and stopping the assistive power. The actuating condition is composed of a pair of a generating condition for generating the assistive power and a stopping condition for stopping the assistive power. A plurality of actuating conditions are set for different electric power consumptions of the motor. The motor controller (1) includes actuating condition shifting means (32) which makes a shift among the plurality of actuating conditions and applies a selected actuating condition to motor control.