E-bike Controller Dynamics for Assist Ratio Optimization
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Solution Overview
Problem
Existing human-powered vehicle control devices do not adequately improve usability by effectively adjusting motor output and assist ratios based on transmission information and user input conditions.
Innovation Solution
A human-powered vehicle control device with an electronic controller that adjusts the maximum motor output, changing ratios of output increase and decrease, in accordance with transmission information, particularly during start-up, low rotational speed, low vehicle speed, and varying user driving force conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the motor output is increased to improve propulsion force, then the vehicle can overcome resistance better, but the user effort and energy consumption increase
Solution Approach 1:
The patent applies dynamics by making the motor output adjustable based on operating conditions. The control device dynamically changes the motor's maximum output value, increasing ratios, and decreasing ratios according to transmission ratio, rotational speed, vehicle speed, and user driving force to optimize the balance between propulsion force and energy consumption.
Solution Approach 2:
The patent implements parameter changes by modifying multiple motor control parameters simultaneously: the maximum output value, the increasing ratio (rate of output increase relative to driving force increase), and the decreasing ratio (rate of output decrease relative to driving force decrease). These parameters are adjusted based on transmission information and operational conditions to achieve optimal performance.
2Speed
If the motor output is increased to assist propulsion, then the vehicle speed can be improved, but the energy consumption increases
Solution Approach 1:
The control device dynamically adjusts motor output based on real-time operating conditions including vehicle speed, rotational speed, and transmission ratio. This dynamic control ensures the motor provides appropriate assistance at each speed level, improving overall vehicle speed performance while minimizing unnecessary energy consumption.
Solution Approach 2:
The system uses feedback from multiple sensors monitoring transmission ratio, rotational speed, vehicle speed, and user driving force to continuously adjust motor output. This closed-loop control ensures energy-efficient operation by matching motor assistance to actual vehicle needs rather than providing constant maximum output.
3Speed
If the motor output changes rapidly to respond to user input, then the responsiveness is improved, but the stability and control precision deteriorate
Solution Approach 1:
The patent introduces two critical parameters for controlling output changes: the increasing ratio (how quickly output increases relative to driving force increase) and the decreasing ratio (how quickly output decreases relative to driving force decrease). By independently adjusting these ratios based on operating conditions, the system achieves both rapid response and stable, controlled transitions.
Data Source
AI summary
A human-powered vehicle control device for a human-powered vehicle comprises an electronic controller. The electronic controller is configured to control a motor, which applies a propulsion force to the human-powered vehicle, in accordance with a human driving force input to the human-powered vehicle. The electronic controller is configured to control the motor to change at least one of a maximum value of an output of the motor, a first changing ratio of an increase rate of the output of the motor to an increase rate of the human driving force, and a second changing ratio of a decrease rate of the output of the motor to a decrease rate of the human driving force in accordance with transmission information related to a transmission ratio in a power transmission path between an input rotational shaft of the human-powered vehicle and a wheel of the human-powered vehicle.