Electric Bicycle Torque Feedback Without Internal Gear Shifting
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Solution Overview
Problem
Current electric bicycles with internal gear shifting mechanisms are bulky, heavy, and difficult to assemble, leading to increased weight and reduced comfort due to varying riding efforts required by the rider, especially when transitioning between different road conditions.
Innovation Solution
A control system for electric bicycles that includes a pedal torque sensor, micro-control circuit, and motor driver to adjust motor output torque based on real-time pedal forces, eliminating the need for an internal gear shifting mechanism and maintaining consistent rider effort across varying road conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an internal gear shifting mechanism is used to adjust speed and riding effort, then the bicycle can adapt to different road conditions, but the bicycle becomes bulky, heavy, and difficult to assemble
Solution Approach 1:
The patent replaces the mechanical internal gear shifting mechanism with an electronic control system that uses a motor driver and controller to adjust motor output torque. The controller receives pedal torque sensor signals and adjusts motor driving signals accordingly, eliminating the need for mechanical gears and shifters while maintaining adaptability to different road conditions.
Solution Approach 2:
The patent changes the operating parameter from mechanical gear ratios to electronic torque control. By continuously adjusting the motor output torque based on real-time pedal torque measurements, the system achieves variable speed and effort control without mechanical gear shifting, thereby reducing device complexity.
2Speed
If an internal gear shifting mechanism is used to control speed, then the bicycle can maintain speed control capability, but the weight of the bicycle increases
Solution Approach 1:
The patent eliminates the heavy mechanical internal gear shifting mechanism and replaces it with a lightweight electronic control system. The motor driver and controller adjust speed control by varying motor output torque based on pedal torque sensor feedback, achieving the same speed control function with significantly reduced weight.
3Ease of operation
If an internal gear shifting mechanism is used to adjust riding effort, then the bicycle can accommodate different rider efforts, but the assembly process becomes difficult
Solution Approach 1:
The patent replaces the complex mechanical internal gear shifting mechanism with a simplified electronic control system. The controller automatically adjusts motor output torque based on real-time pedal torque sensor signals, eliminating the need for manual gear shifting operations and simplifying the assembly process by removing numerous mechanical components.
4Weight of moving object
If the internal gear shifting mechanism is removed to reduce weight, then the bicycle weight decreases, but the ability to handle varying road conditions may be compromised
Solution Approach 1:
The patent compensates for the removal of the mechanical gear shifting mechanism by implementing an electronic control system that uses a pedal torque sensor and motor driver. This system continuously monitors pedal torque and adjusts motor output torque accordingly, providing adaptability to varying road conditions through electronic control rather than mechanical means.
Solution Approach 2:
The patent employs a feedback control mechanism where the pedal torque sensor continuously measures actual pedal torque, the controller compares this with reference values, and adjusts the motor driving signal accordingly. This closed-loop feedback system ensures that the bicycle maintains appropriate riding characteristics across different road conditions despite the elimination of mechanical gear shifting.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides improved comfort by maintaining a consistent pedal force requirement regardless of road conditions and reduces the bicycle's weight and assembly complexity by eliminating the internal gear shifting mechanism.
Implementation Method 1
a pedal torque sensor (1), a micro-control circuit (2), a motor driver (3) and a motor (4). The pedal torque sensor (1) is configured to sense a plurality of pedal torques during a traveling period of the electric bicycle
Implementation Method 2
The motor (4) is electrically connected to the motor driver (3) and generates a motor output torque (MT1) according to the motor driving signal (MS1)
Data Source
AI summary
An electric bicycle, a control system of the electric bicycle and a control method thereof are provided. The control system includes a pedal torque sensor, a micro-control circuit, a motor driver and a motor. The pedal torque sensor senses a plurality of pedal torques during a traveling period of the electric bicycle. The micro-control circuit is electrically connected to the pedal torque sensor and saves a reference pedal force. The micro-control circuit calculates an average pedal force based on the plurality of pedal torques and the traveling period, and generates a control signal based on a comparison result of the reference pedal force and the average pedal force. The motor driver is electrically connected to the micro-control circuit and generates a motor driving signal according to the control signal. The motor generates a motor output torque according to the motor driving signal.