Regenerative Braking Control for Electric Bicycles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Pedal-driven vehicles with electric auxiliary motors face difficulties in smooth and efficient recuperation control, often leading to non-use of energy recovery due to jerky manual switching between recuperation and friction braking.

Innovation Solution

A method that detects the direction of rotation of the crank mechanism, allowing for easy and safe energy recuperation by reversing pedaling direction, with automatic start and end points, and optional electric holding brake for safety and theft protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual switching between recuperation and friction brake is used, then control is possible, but the switching is jerky and difficult to operate

Engineering Contradiction:
Improveease of recuperation controlVSAvoidcontrol mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent inverts the conventional approach by using backward pedaling (reverse direction) to activate recuperation instead of forward pedaling or manual button pressing. This inversion makes the control intuitive and eliminates jerky switching, as the natural backward motion of the cyclist directly engages the regenerative braking system without complex manual intervention.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The system enables self-service control where the cyclist's natural backward pedaling motion automatically triggers recuperation without requiring manual operation of switches or buttons. The control system detects the reverse rotation direction and autonomously activates the regenerative braking, making the system serve itself through the user's natural movement.

Inventive Principle:
Principle #25Self-service

2Loss of energy

If manual switching between recuperation and friction brake is used, then control is possible, but energy recovery is not utilized in everyday operation

Engineering Contradiction:
Improveenergy recovery efficiencyVSAvoidoperational convenience
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

By inverting the control mechanism to use backward pedaling for activation, the system becomes as easy to use as conventional braking, removing the barrier to everyday energy recovery utilization. The intuitive reverse-motion activation ensures cyclists will actually use recuperation in normal operation rather than relying on manual switching.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If backward pedaling is used to activate recuperation, then control is simplified, but false activation with short backward steps must be prevented

Engineering Contradiction:
Improvesimplicity of controlVSAvoidaccurate recuperation activation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system requires a minimum threshold of backward pedaling action (predetermined angle of rotation) to activate recuperation. This partial action requirement filters out accidental or incomplete backward movements while still maintaining simplicity for the user, as natural backward pedaling easily exceeds the threshold without requiring precise control.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The control system continuously monitors the rotation direction and angle of the crank mechanism, providing real-time feedback to determine when the predetermined threshold is met. This feedback mechanism ensures reliable activation only when sufficient backward motion is detected, preventing false activation while maintaining simple control.

Inventive Principle:
Principle #23Feedback

4Reliability

If electric holding brake is activated by backward torque, then safety and theft protection are improved, but complex detection and control is required

Engineering Contradiction:
Improvevehicle securityVSAvoidtorque detection complexity
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The existing torque sensor used for detecting pedaling force is made multi-functional by also using it to detect backward torque for activating the electric holding brake. This universal use of the same sensor simplifies the detection system, eliminating the need for separate sensors or complex detection mechanisms while improving vehicle security.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 quick, efficient, and user-friendly energy recovery by simplifying the control process, reducing the need for complex manual controls and minimizing braking energy expenditure, while ensuring safe and secure vehicle operation.

Implementation Method 1

the electric auxiliary drive is operated in recuperation when the direction of rotation of the crank mechanism is directed backwards

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2480446B1Apparatus and method to control regenerative braking in a pedal vehicle
Publication Date: 2014.02.12 ROBERT BOSCH GMBH
  • EP2480446B1 patent drawingFigure 1~2

AI summary

The present invention relates to a method for regulating regeneration in a pedal-driven vehicle (1) having a crank drive (5), in particular in a bicycle, wherein the vehicle has an electric auxiliary drive (2) and a rechargeable energy source (3), comprising the steps of sensing a direction of rotation (A) of the crank drive (5) and regenerating energy and storing energy in the energy source (3) if a direction of rotation (A) of the crank drive (5) is in the rearward direction. In addition, the invention relates to a vehicle with a crank drive (5), in particular a bicycle, comprising an electric auxiliary drive (2), a control unit (6) and a sensor (4) for sensing a direction of rotation of the crank drive (5), wherein the control unit (6) is configured to operate the electric auxiliary drive (2) in regeneration mode if the sensor (4) senses a rearward-directed direction of rotation of the crank drive (5).