Electrically assisted bicycle motor control modes
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Solution Overview
Problem
Existing electrically assisted bicycles have limited motor output characteristics, which do not adapt well to varying rider preferences and situations, affecting riding comfort.
Innovation Solution
The electrically assisted bicycle incorporates an inclination sensor to select between two control modes based on the bicycle's pitch angle, and a propelling detection sensor to determine when to apply assisting torque, allowing for wider output characteristics through the selection of either immediate or delayed torque application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single control mode is used for motor assistance, then the control system is simple, but the output characteristics are limited and cannot adapt to different riding situations
Solution Approach 1:
The patent implements multiple control modes (first control mode and second control mode) that can be dynamically switched based on riding conditions. The control module selects different control strategies according to the detected riding state, allowing the motor assistance characteristics to adapt flexibly to different situations while maintaining a relatively simple overall system structure through mode-based adaptation rather than completely different control architectures
2Speed
If motor torque is applied immediately in response to pedal effort, then the response speed is fast, but the riding comfort is reduced on inclined terrains
Solution Approach 1:
The patent dynamically adjusts the torque application strategy based on detected riding conditions. In the first control mode, motor torque is applied immediately in response to pedal effort for fast response. In the second control mode, the torque application is delayed or adjusted for inclined terrains to improve riding comfort. The control module automatically switches between these modes based on real-time condition detection
Solution Approach 2:
The patent changes the control parameters (torque application timing and magnitude) based on the detected riding state. When transitioning between control modes, the system adjusts parameters such as the response delay time and torque magnitude to optimize both response speed and riding comfort for different terrain conditions
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An electrically assisted bicycle has a crank shaft 49, pedals 33, 34, an electric motor 60, a pedal effort sensor 101 for detecting pedal effort exerted on the pedals 33, 34, a propelling detection sensor 102 for detecting that the electrically assisted bicycle is started to be propelled, and a control module 105 for executing a first control in which a command value to the electric motor 60 is obtained based on the output of the pedal effort sensor 10i and a second control in which a command value to the electric motor 60 is obtained based on the output of the pedal effort sensor 101 and the output of the propelling detection sensor 102. The control module 105 is configured to select the first control or the second control as a calculation method of a command value given to the electric motor 60 during a period of time from a state where the electrically assisted bicycle 1 is stopped until a detection of the rotation of the crank shaft 41.