Bicycle Shift Control Using Actuator-Driven Chain During Pedaling
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Solution Overview
Problem
Existing control systems for human-powered vehicles do not adequately address the comfort of riders during shifting operations, particularly when pedaling is stopped or reduced.
Innovation Solution
A control system that includes an actuator to drive the chain while shifting is stopped, using detection information such as torque, cadence, crank angle, speed, inclination, and acceleration to control the actuator and transmission based on predetermined thresholds, ensuring smooth transitions during shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the motor is stopped immediately before shifting (conventional approach), then the shifting operation can be performed, but the rider experiences discomfort during pedaling
Solution Approach 1:
The controller stops the motor in advance before the shifting operation begins, rather than stopping it reactively. This preliminary action allows the shifting to occur without motor interference while maintaining rider comfort by coordinating the stop timing with the shifting initiation signal.
Solution Approach 2:
The controller detects a shifting initiation signal from the operation unit and uses this feedback to determine when to stop the motor. This feedback mechanism ensures the motor stops at the appropriate moment to enable smooth shifting while maintaining overall system coordination and rider comfort.
2Object-affected harmful factors
If the chain is driven by the actuator during shifting operation, then rider comfort is improved, but control complexity increases
Solution Approach 1:
The controller electronically coordinates the actuator and motor operations to replace complex mechanical synchronization mechanisms. By using electronic control signals and timing coordination, the system achieves smooth chain-driven shifting without requiring additional mechanical synchronization devices.
Solution Approach 2:
The controller serves multiple functions: it detects shifting initiation signals, controls motor stopping, coordinates actuator operation, and manages chain-driven shifting. This multi-functionality consolidates what could be separate control systems into a single integrated controller, managing complexity through consolidation rather than proliferation of components.
Data Source
AI summary
A control system includes a controller configured to control an actuator and at least one transmission such that a chain is driven by the actuator and a shifting operation is performed by the at least one transmission. In a case where a pedal is operated during the shifting operation, the controller is configured to control the actuator so that the shifting operation is stopped in accordance with a result of comparison with a predetermined threshold.