Bicycle Transmission Control for Deceleration-Aware Shifting
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Solution Overview
Problem
Existing shifting control devices for human-powered vehicles do not effectively adapt transmission ratios to provide comfortable traveling conditions, particularly during deceleration and varying environmental conditions.
Innovation Solution
A control device with an electronic controller that adjusts the transmission ratio based on multiple shifting conditions, including deceleration, vehicle speed, torque, and environmental factors like road gradient, to facilitate smooth and comfortable travel by shifting the transmission ratio regardless of initial conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the transmission ratio is adjusted based only on basic shifting conditions (cadence, torque, power), then the control system remains simple, but the traveling comfort during deceleration and varying environmental conditions deteriorates
Solution Approach 1:
The control system dynamically adjusts transmission ratio based on multiple changing parameters including deceleration rate, vehicle speed, torque, power, and environmental conditions. The system transitions from static threshold-based control to dynamic multi-parameter control, enabling adaptive response to varying riding conditions and improving traveling comfort.
Solution Approach 2:
The system monitors and responds to changes in multiple parameters simultaneously (deceleration rate, vehicle speed, torque, power, temperature, humidity). By detecting parameter changes and adjusting transmission ratio accordingly, the system provides optimized control for different riding scenarios while maintaining manageable complexity through structured control logic.
2Ease of operation
If the transmission ratio is shifted based on multiple travel conditions including deceleration and environmental factors, then traveling comfort is improved, but the control logic and processing requirements increase
Solution Approach 1:
The control logic is segmented into distinct functional modules: deceleration detection module, environmental condition detection module, transmission ratio determination module, and control execution module. Each module handles specific aspects of the control process, making the overall complex system manageable through modular design and clear separation of concerns.
Solution Approach 2:
The system continuously monitors multiple parameters (deceleration rate, vehicle speed, torque, power, temperature, humidity) and uses this feedback to dynamically adjust transmission ratio. The feedback mechanism enables the system to respond to changing conditions in real-time, improving traveling comfort while maintaining structured control logic through systematic information flow.
3Measurement precision
If the system monitors multiple travel parameters (deceleration, speed, torque, power, environment), then the transmission ratio adjustment accuracy is improved, but the measurement and detection requirements increase
Solution Approach 1:
The control system integrates multiple detection functions into a unified control apparatus. Existing sensors (cadence sensor, torque sensor, speed sensor) serve multiple purposes in the overall control strategy, while environmental sensors add complementary information. This multi-functional approach improves measurement precision without proportionally increasing detection complexity.
Solution Approach 2:
The system combines detection of multiple parameters (deceleration rate from speed changes, environmental conditions from temperature and humidity sensors) with transmission ratio control in a single integrated system. By merging these detection and control functions, the system achieves accurate transmission ratio adjustment while avoiding the complexity of separate independent systems.
Data Source
AI summary
A control device and a transmission system are provided that allow for comfortable traveling with a human-powered vehicle. The control device includes an electronic controller configured to control a transmission to shift a transmission ratio of a human-powered vehicle in accordance with a first shifting condition set based on a first reference value. The electronic controller is configured to shift the transmission ratio of the human-powered vehicle regardless of the first shifting condition upon determining a second shifting condition set based on travel information related to traveling of the human-powered vehicle is satisfied.