E-Bike Motor Torque Control for Uphill Position Stability
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Solution Overview
Problem
Electrically assisted bicycles with walk-push functions struggle to maintain stability on uphill slopes, often causing the vehicle to move backwards when attempting to output walk-push assisting torque, making it difficult for riders to stay in a desired position.
Innovation Solution
An electrically assisted bicycle with an electric motor that applies walk-push assisting torque to the wheel, featuring a control unit that executes three modes: a stay mode to maintain position, a walk-push mode for propulsion, and a mode selection mechanism via an operating unit, allowing riders to choose the appropriate mode for their action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electric motor outputs walk-push assisting torque automatically when the rider pushes the bicycle while walking, then the rider can obtain propulsion assistance, but the bicycle may move backwards on uphill slopes before the torque is applied, making it difficult for the rider to stay in the desired position
Solution Approach 1:
The control unit determines whether to output walk-push assisting torque in advance by evaluating conditions (rider pushing action detection, vehicle speed, gradient) before the torque is actually applied. This preliminary determination prevents the bicycle from moving backwards unexpectedly and allows the rider to stay in the desired position.
Solution Approach 2:
The system dynamically switches between different operating modes (first mode with no torque, second mode with stay assisting torque, third mode with walk-push assisting torque) based on real-time conditions. This dynamic adaptation allows the bicycle to respond appropriately to the rider's needs while maintaining position control on uphill slopes.
2Productivity
If the bicycle moves forwards while walk-push assisting torque is being outputted, then propulsion is provided, but the rider cannot easily control when to start and stop the assistance
Solution Approach 1:
The control unit continuously monitors vehicle speed, rider pushing action, and other parameters to determine when to start and stop torque output. This feedback mechanism allows the rider to have precise control over when assistance begins and ends, improving ease of operation while maintaining productivity.
3Device complexity
If a single operating unit is used to select between multiple modes, then the device complexity is reduced, but the ease of operation for mode selection may be compromised
Solution Approach 1:
The single operating unit is designed to perform multiple functions: detecting rider pushing action, determining vehicle speed, and selecting between different torque output modes. This multi-functionality reduces device complexity while maintaining ease of operation through intelligent control logic that automatically interprets the rider's intentions.
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
Enables riders to easily stay or move on an uphill slope by selecting the appropriate mode, ensuring the electric motor's output does not interfere with their intended action, enhancing convenience and control.
Implementation Method 1
an electric motor that is adapted to apply walk-push assisting torque to a wheel of the bicycle
Data Source
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AI summary
There is provided an electrically assisted bicycle 1 having an electric motor 60 which applies walk-push assisting torque to a rear wheel 22 of the bicycle when a rider propels the bicycle by pushing it while walking, a motor control module 95 configured to execute a first mode in which the electric motor 60 applies no torque to the rear wheel 22, a second mode in which the electric motor 60 applies to the rear wheel 22 stay assisting torque which allows the electrically assisted bicycle 1 to stay in a position where the rider wants to stay and a third mode in which the electric motor 60 applies walk-push assisting torque to the rear wheel 22, wherein the first mode, the second mode and the third mode can be selected by using an operating unit 56 which can be operated by the rider.