Bicycle Gear Shifting Overlap Control for Comfort
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Solution Overview
Problem
Existing automatic shifting systems for bicycles can be uncomfortable due to predefined hysteresis-based shift points, which do not account for the dynamic driving behavior and situation, leading to unnecessary gear shifting.
Innovation Solution
A method and device that assign gear ranges with overlapping areas based on bicycle speed, cadence, and GPS signals, allowing gear engagement decisions based on driving behavior and speed progression, using a gear range assignment unit, limit range assignment unit, and speed detection unit to determine optimal gear shifts within these areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hysteresis-based shift points are used to prevent frequent gear shifting, then gear shifting stability is improved, but riding comfort deteriorates due to unnecessary gear shifts
Solution Approach 1:
The patent applies dynamics by making the gear shift control adaptive rather than static. The control unit dynamically adjusts shift decisions based on the detected riding style (sporty or relaxed) and current riding situation (acceleration, deceleration, constant speed). This allows the system to optimize between stability and comfort in real-time, resolving the contradiction by making the control characteristics flexible rather than fixed.
Solution Approach 2:
The patent changes control parameters based on detected riding style and situation. When sporty riding style is detected, the system uses one set of shift thresholds and hysteresis values, while relaxed riding style triggers different parameters. This parameter adaptation allows the system to maintain stability when needed while avoiding unnecessary shifts that reduce comfort, thus resolving the contradiction through conditional parameter modification.
2Device complexity
If predefined shift points are used for automatic gear shifting, then control simplicity is improved, but adaptability to different riding behaviors deteriorates
Solution Approach 1:
The patent implements self-service by enabling the system to automatically detect and adapt to the rider's preferred style without manual intervention. The control unit monitors riding patterns and autonomously determines whether the rider prefers sporty or relaxed riding, then automatically adjusts shift behavior accordingly. This eliminates the need for manual setup while providing personalized control, resolving the contradiction between simplicity and adaptability.
Solution Approach 2:
The system uses feedback by continuously monitoring riding parameters (acceleration, deceleration, speed changes) and using this information to adapt shift decisions. The control unit analyzes the feedback from riding behavior and adjusts the gear shifting strategy in real-time, enabling the system to adapt to different riding styles while maintaining a simple automated control interface for the rider.
3Productivity
If hysteresis is applied to reduce frequent shifting, then gear shift frequency is reduced, but responsiveness to actual riding needs deteriorates
Solution Approach 1:
The patent applies local quality by implementing different hysteresis characteristics for different riding situations. Instead of a uniform hysteresis value, the system applies localized control strategies: larger hysteresis for stable cruising conditions to reduce unnecessary shifts, and smaller or adaptive hysteresis during acceleration or deceleration phases to maintain responsiveness. This localized adaptation resolves the contradiction by making hysteresis context-dependent rather than global.
Data Source
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AI summary
The present invention relates to a method for controlling automatic shifting operations of an electric gearshift device of a bicycle, wherein each gear (1, 2,..., i,...n) is assigned a predetermined gear range (G1, G2, G3, ..., Gi; ...; Gn), and each gear range is assigned a predetermined lower limit (uG1; uG2; uGi) and a predetermined upper limit (oG1, oG2, oGi), wherein the upper limit (oGi) of a gear range (Gi) is always greater by a predetermined value than the lower limit (uGi+1) of the next higher gear range (Gi+1), wherein the upper limit (oGi) of a gear range (Gi) and the lower limit (uGi+1) of the next higher gear range (Gi+1) define an overlap range (Üi/i+1) between them, wherein in the overlap range (Üi/i+1) depending on the course The speed v determines whether gear i or gear i+1 is engaged.