Battery-Assisted Bicycle Walking Speed Control

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Solution Overview

Problem

Existing battery-assisted bicycles are cumbersome to maneuver when walked without riding, as they are heavy and require multiple operations to adjust speed, which does not suit user preferences effectively.

Innovation Solution

A battery-assisted bicycle system that includes an operation unit capable of switching between first and second operation signals to adjust vehicle speed and driving force, allowing the electric motor to assist movement with reduced operational effort by determining the bicycle's state and maintaining selected speeds or forces through feedback control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the electric motor is operated to assist movement when the user walks the battery-assisted bicycle, then the ease of operation is improved, but the weight of the bicycle increases

Engineering Contradiction:
Improveease of movement when walkedVSAvoidbicycle weight
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The bicycle system automatically detects when the user is walking (no pedal effort) and activates the electric motor to assist movement, making the system self-regulating without requiring manual intervention from the user

Inventive Principle:
Principle #25Self-service

2Device complexity

If the number of set vehicle speeds is limited, then the device complexity is reduced, but the adaptability decreases

Engineering Contradiction:
Improvespeed selection mechanismVSAvoidspeed selection flexibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts the number of vehicle speeds based on the detected walking speed of the user, allowing the bicycle to adapt between different speed ranges (first range for slower speeds, second range for faster speeds) rather than using a fixed set of speeds

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit changes the parameter of vehicle speed range based on detected walking speed, switching between a first vehicle speed range and a second vehicle speed range to accommodate different user needs without increasing device complexity

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the user must operate both the acceleration switch and the unlocking switch, then the reliability of speed selection is improved, but the ease of operation worsens

Engineering Contradiction:
Improvespeed selection accuracyVSAvoidspeed selection convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system merges the functions of the acceleration switch and unlocking switch into a single operation unit, allowing the user to select vehicle speeds by operating only the operation unit without needing to coordinate multiple switches

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2957449B1Battery-assisted bicycle
Publication Date: 2023.04.12 YAMAHA MOTOR CO LTD
  • EP2957449B1 patent drawingFigure 1
  • EP2957449B1 patent drawingFigure 2
  • EP2957449B1 patent drawingFigure 3

AI summary

Assist that suits the user's preference is carried out without increasing the number of times of operation to select a vehicle speed when the user walks the battery-assisted bicycle without riding the battery-assisted bicycle. The battery-assisted bicycle (1) includes an electric motor (61), a vehicle speed detector (95) that detects a vehicle speed, a first state determiner (151) that determines whether the battery-assisted bicycle (1) is in a first state in which the battery-assisted bicycle (1) has a vehicle speed with no pedal effort, an operation unit (190), a vehicle speed setter (155) that sets a detection result from the vehicle speed detector (95) at time of input of an operation signal as a first vehicle speed if it is determined that the battery-assisted bicycle (1) is in the first state and the operation signal is input from the operation unit (190), and a motor controller (105) that controls driving of the electric motor (61) so that the first vehicle speed is maintained at time of input of the operation signal and thereafter if it is determined that the battery-assisted bicycle (1) is in the first state and the operation signal is input from the operation unit (190).