E-Bike Motor Control Using Cadence and Pedaling Torque Thresholds

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Solution Overview

Problem

Current electric assisted bicycles do not effectively analyze and process speed, pedaling torque, and throttle output values, leading to an uncomfortable riding experience due to inadequate motor control.

Innovation Solution

A driving device and method that utilizes a motor, rotation speed sensor, and torque sensor to control motor output based on rotation speed and average torque values, with distinct thresholds for idle, high-speed, and intermediate riding conditions, ensuring motor output is proportional to these values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the controller directly controls motor output based on single parameter (speed, torque, or throttle), then the control system is simple, but the riding experience is uncomfortable and does not meet user requirements

Engineering Contradiction:
Improveriding experienceVSAvoidcontrol system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent segments the control logic into distinct operating modes (low-speed mode and high-speed mode) based on rotation speed thresholds. The controller divides the operating range and applies different control strategies to each segment, enabling complex adaptive control while maintaining manageable system architecture through modular control logic

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic control by automatically switching between different control modes based on real-time rotation speed feedback. The controller dynamically adjusts the control strategy (torque-based vs. speed-based) according to the current operating state, making the control system adaptive to varying riding conditions without requiring manual intervention

Inventive Principle:
Principle #15Dynamics

2Force

If the controller uses torque-based control for all speed ranges, then low-speed torque response is good, but high-speed performance becomes inadequate and motor output exceeds needs

Engineering Contradiction:
Improvetorque responseVSAvoidmotor energy consumption
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The patent dynamically switches control modes based on rotation speed. At low speeds, torque-based control provides strong force response. When rotation speed exceeds the threshold, the system dynamically transitions to speed-based control, preventing excessive motor output and reducing energy consumption during high-speed operation while maintaining adequate performance

Inventive Principle:
Principle #15Dynamics

3Speed

If the controller uses speed-based control for all conditions, then high-speed performance is good, but low-speed torque assistance becomes insufficient

Engineering Contradiction:
Improvehigh-speed performanceVSAvoidtorque assistance
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The patent segments the speed range into two distinct operating regions separated by a threshold value. The low-speed segment (below threshold) uses torque-based control to ensure adequate torque assistance. The high-speed segment (above threshold) uses speed-based control to optimize high-speed performance. This segmentation ensures both low-speed torque response and high-speed performance are adequately addressed

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4063251B1Driving device and driving method for electric assisted bicycle
Publication Date: 2025.12.31 ACER INC
  • EP4063251B1 patent drawingFigure 1
  • EP4063251B1 patent drawingFigure 2~3
  • EP4063251B1 patent drawingFigure 4

AI summary

A driving device (100) and a driving method for an electric assisted bicycle are provided. The driving device (100) includes a motor (110), a rotation speed sensor (120), a torque sensor (130) and a controller (140). The rotation speed sensor (120) senses a rotation speed value (VI) of a crank (160) or a chainring (150) of the electric assisted bicycle. The torque sensor (130) obtains an average torque value (V2) applied by the crank (160) to the chainring (150) of the electric assisted bicycle. The controller (140) controls an output of the motor (110) in response to the rotation speed value (VI) and the average torque value (V2).