Electronic Controller Shifting Strategy for Human-Powered Vehicle
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Solution Overview
Problem
Existing control devices for human-powered vehicles do not efficiently manage the shifting of gear ratios, particularly in scenarios where rapid changes in vehicle state parameters such as rotational speed, vehicle speed, or road gradient occur, leading to suboptimal performance and efficiency.
Innovation Solution
A control device with an electronic controller that manages a transmission device capable of shifting gear ratios in stages, with a first shifting action shifting by one stage under basic conditions and a second shifting action shifting by two or more stages when specific vehicle state conditions are met, utilizing an external shifting device to move the chain between sprockets, optimizing gear ratio changes based on detected parameters like rotational speed, vehicle speed, and road gradient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the transmission device performs a first shifting action that shifts the ratio by only one stage, then the shifting operation is simple and reliable, but the response speed to vehicle state changes is slow
Solution Approach 1:
The patent implements dynamic shifting control where the transmission device can perform either a first shifting action (one stage) or a second shifting action (two or more stages) based on real-time vehicle state parameters. The electronic controller dynamically selects the shifting strategy by comparing the change amount of vehicle state parameters against predetermined thresholds, enabling the system to adapt between conservative one-stage shifting and aggressive multi-stage shifting to optimize response speed while maintaining control reliability.
2Speed
If the transmission device shifts the ratio by two or more stages quickly, then the response to vehicle state changes is fast, but the risk of improper shifting increases
Solution Approach 1:
The patent employs feedback control where the electronic controller continuously monitors vehicle state parameters (rotational speed, vehicle speed, acceleration, gradient) and uses this feedback to determine whether to execute the first or second shifting action. The controller calculates the change amount of these parameters and compares it against predetermined thresholds, ensuring that multi-stage shifting is only performed when the vehicle state justifies such aggressive action, thereby maintaining reliability while enabling fast response when needed.
Solution Approach 2:
The patent changes the shifting behavior based on parameter thresholds by implementing different shifting strategies (one stage vs. two or more stages) according to the magnitude of vehicle state parameter changes. When the change amount exceeds the predetermined threshold, the system transitions from conservative one-stage shifting to aggressive multi-stage shifting, optimizing the balance between response speed and reliability based on actual operating conditions.
3Loss of time
If the transmission device performs multiple first shifting actions sequentially, then the shifting operation is safe and controlled, but the total time to achieve the same ratio change is longer
Solution Approach 1:
The patent implements a skipping strategy where, under certain conditions (when vehicle state parameter change exceeds the threshold), the transmission device performs a second shifting action that skips intermediate stages and shifts by two or more stages in one operation. This allows the system to rush through multiple gear ratio changes that would otherwise require sequential one-stage shifts, significantly reducing the time required for ratio changes and improving shifting efficiency during critical vehicle state transitions.
Data Source
AI summary
A human-powered vehicle control device includes an electronic controller that controls a transmission device to shift a ratio of a rotational speed of a wheel to a rotational speed of a crank axle in stages. The controller controls the transmission device so that the transmission device performs a first shifting action that shifts the ratio by only one stage in a case where a shifting condition is satisfied. The transmission device is controlled by the electronic controller so that the transmission device performs a second shifting action that shifts the ratio by two or more stages in a case where the shifting condition is satisfied and a vehicle state of the human-powered vehicle is a predetermined state. The predetermined state includes a state in which a change amount of a parameter related to the vehicle state is a predetermined amount or greater.