Electric Bicycle Controller Torque Response
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Solution Overview
Problem
Existing electric bicycles experience shock and reduced responsiveness when the electric motor engages with the power transmission member due to mechanical lag and inefficient torque transmission, which affects the compatibility of moderation and responsiveness.
Innovation Solution
A controller for an electric bicycle that includes a pedal torque-dependent power supply, an acceleration power supply, and a moderate power supply, where the acceleration power is provided before the maximum pedal torque peak to enhance responsiveness and moderate power is supplied after the acceleration phase to reduce shock, ensuring smooth engagement with the power transmission member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If soft start is performed to moderate shock, then shock is moderated, but responsiveness is deteriorated
Solution Approach 1:
The controller performs preliminary acceleration by supplying acceleration power larger than pedal torque-dependent power before the maximum pedal torque peak occurs. This preliminary action increases the rotation number of the electric motor in advance, so that when the motor engages with the power transmission member, the shock is moderated while maintaining responsiveness.
Solution Approach 2:
The controller dynamically switches between different power supply modes (acceleration power supply, moderate power supply, and pedal torque-dependent power supply) based on the pedaling phase. By making the power supply characteristics changeable according to the timing of pedal torque variations, the system achieves both shock moderation and improved responsiveness.
2Speed
If acceleration power larger than pedal torque-dependent power is supplied before maximum pedal torque peak, then responsiveness is improved, but shock may increase
Solution Approach 1:
The power supply process is segmented into distinct phases: acceleration power supply phase (before maximum pedal torque peak), moderate power supply phase (after acceleration power), and pedal torque-dependent power supply phase. This segmentation allows the system to provide large acceleration power when needed while subsequently reducing power to moderate shock, achieving both responsiveness and shock moderation.
Solution Approach 2:
The controller applies acceleration power periodically based on the pedaling cycle, specifically before the maximum pedal torque peak occurs. This periodic acceleration action is synchronized with the natural pedaling rhythm, allowing the motor to build up rotation speed at appropriate moments without causing continuous shock.
3Object-affected harmful factors
If moderate power is supplied after acceleration power, then shock is moderated, but responsiveness may be reduced
Solution Approach 1:
The moderate power supply acts as a preliminary damping action that occurs after the acceleration phase. By supplying moderate power (smaller than acceleration power) at this timing, the system prepares for the upcoming engagement with the power transmission member, ensuring that excessive shock is avoided while the motor maintains sufficient rotation speed for responsive operation.
Data Source
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AI summary
A controller for an electric bicycle includes a pedal torque-dependent power supply part 113 that supplies pedal torque-dependent power, which is changed in response to the change of a signal output from a pedal torque detecting part detecting torque input to pedals, an acceleration power supply part 12 that supplies acceleration power before the time at which the maximum peak is formed in a signal output from the pedal torque detecting part while pedals make one rotation after torque is input to the pedals, and a moderate power supply part 112 that supplies moderation power before the time at which the maximum peak is formed in the signal output from the pedal torque detecting part while the pedals make one rotation torque is input to the pedals, and after the time at which the acceleration power is supplied.