Bicycle Derailleur Control Using Sprocket Gate Data

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Solution Overview

Problem

Existing bicycle component control systems for gear shifting lack precision in controlling actuator movement based on sprocket assembly information, leading to inefficient and sometimes rough shifting operations, especially during double downshifts or upshifts.

Innovation Solution

A bicycle component controller with a data storage device and processor that utilizes sprocket assembly information, including total sprocket numbers and shifting gate information, to perform gear shift control by calculating single shifting distances and predetermined periods for smooth and appropriate shifting operations, even in cases where upshifting or downshifting gates are limited.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a motorized derailleur is used for automatic gear shifting, then shifting operation is automated, but precision in controlling actuator movement is insufficient

Engineering Contradiction:

Improveautomatic gear shiftingVSAvoidactuator movement precision

Core Design Contradiction:

Extent of automationVSManufacturing precision

Solution Approach 1:

The system changes control parameters by calculating specific actuator movement amounts based on sprocket assembly information. The controller determines precise movement distances for each gear shift operation, adjusting the actuator control parameters dynamically to achieve smooth and accurate shifting while maintaining automated operation.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If gear shift control is performed without considering sprocket assembly information, then control process is simple, but shifting precision and smoothness deteriorate

Engineering Contradiction:

Improvecontrol process complexityVSAvoidshifting precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The system performs preliminary action by pre-storing sprocket assembly information including the number of sprockets and shifting gate positions. Before executing a gear shift, the controller retrieves this information and calculates the appropriate actuator movement amount in advance, ensuring precise and smooth shifting without overly complicating the real-time control process.

Inventive Principle:

Principle #10Preliminary action

3Speed

If double downshift command is executed immediately, then shifting speed is fast, but mechanical stress and rough operation increase

Engineering Contradiction:

Improveshifting speedVSAvoidmechanical stress

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The system applies periodic action by inserting a predetermined waiting period between the first and second downshift operations when a double downshift command is received. This timing control allows the first shift to complete and the chain to settle before initiating the second shift, reducing mechanical stress and rough operation while maintaining overall fast shifting performance.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS11685470B2Bicycle component controller, bicycle component control system and bicycle component control method

Publication Date: 2023.06.27 SHIMANO INC

AI summary

A bicycle component controller is basically provided with a data storage device and a processor. The data storage device contains sprocket assembly information of at least one sprocket assembly. The processor is configured to perform a gear shift control based on the sprocket assembly information. The sprocket assembly information of the at least one sprocket assembly at least includes a total sprocket number and shifting gate information. The single shifting distance of the sprocket assembly information corresponds to an axial spacing between adjacent sprockets of the at least one sprocket assembly.