Electric Bicycle Motor Control for Smooth Acceleration
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Solution Overview
Problem
Electric bicycles often experience abrupt starts during travel when the throttle is operated for acceleration, leading to reduced ride comfort and safety concerns.
Innovation Solution
A control method that adjusts the motor's velocity slope or time to reach a target velocity based on the driver's acceleration instruction, traveling velocity, and road surface gradient, preventing abrupt starts by increasing the time to reach the target velocity when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the throttle is operated for acceleration during traveling, then the motor is driven to rotate the wheels and the electric bicycle moves upward, but abrupt start occurs where the electric bicycle is abruptly started at an excessively high velocity
Solution Approach 1:
The patent applies dynamics by making the velocity slope of the motor adjustable rather than fixed. The control unit dynamically changes the velocity slope based on current traveling velocity and acceleration instructions. When the bicycle is already moving, the system reduces the velocity slope to prevent abrupt starts, while maintaining higher acceleration capability when starting from rest or at lower speeds.
Solution Approach 2:
The patent changes the parameter of velocity slope based on operating conditions. The control unit calculates different velocity slopes according to the current traveling velocity and the acceleration instruction from the throttle. This parameter adaptation allows the system to provide strong acceleration when needed while preventing excessive acceleration that would cause abrupt starts during traveling.
2Reliability
If the velocity slope of the motor is reduced to prevent abrupt start, then ride comfort is improved, but the time taken to reach target velocity increases
Solution Approach 1:
The system dynamically adjusts the velocity slope based on real-time conditions rather than using a fixed conservative value. By calculating the appropriate velocity slope according to current traveling velocity and acceleration requirements, the system achieves the right balance between comfort and acceleration performance for each specific situation.
Solution Approach 2:
The velocity slope parameter is changed adaptively based on operating conditions. When the bicycle is already traveling at higher speeds, the velocity slope is reduced to ensure comfort. When at lower speeds or during normal acceleration scenarios, the velocity slope allows for faster acceleration, thus minimizing time loss while maintaining comfort when necessary.
Data Source
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AI summary
Disclosed herein are an electric bicycle and a control method thereof. The control method of the electric bicycle in which a motor is rotated using electric energy stored in a battery to drive the electric bicycle, includes receiving an acceleration instruction value to accelerate the electric bicycle, input by a driver, during traveling, calculating a reference value according to a traveling velocity of the electric bicycle, and increasing time taken for a rotating velocity of the motor to reach a target velocity, if the received acceleration instruction value is more than the calculated reference value.