Motorcycle Brake Control With Front Friction and Rear Regeneration

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Solution Overview

Problem

The existing brake systems for straddle-type vehicles, particularly those with rear-wheel-driven electric motors, face safety issues due to insufficient braking force when the battery is full or the rotational frequency of the rear wheel is reduced, leading to inadequate regenerative torque generation.

Innovation Solution

A brake system for straddle-type vehicles that includes a front-wheel friction brake mechanism and a rear-wheel regenerative brake mechanism, allowing independent control of friction braking force on the front wheel, regardless of the operation element's motion, and integrated control of both mechanisms to ensure consistent braking force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a regenerative brake mechanism is used to store electric power generated by the rear wheel, then energy recovery is improved, but braking force becomes insufficient when the battery is full or rotational frequency is reduced

Engineering Contradiction:
Improveenergy recoveryVSAvoidbraking force reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The brake system is divided into two independent mechanisms: a regenerative brake mechanism for energy recovery and a friction brake mechanism for reliable braking. The friction brake mechanism operates independently on the front wheel, while the regenerative brake operates on the rear wheel, allowing each to function optimally without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the operational parameters by applying friction braking force selectively to the front wheel through the friction brake mechanism, while the regenerative brake mechanism handles the rear wheel. This parameter differentiation ensures that braking performance is maintained regardless of battery charge state or rotational frequency conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the friction brake mechanism is the only braking system, then braking reliability is improved, but energy recovery capability is lost

Engineering Contradiction:
Improvebraking force reliabilityVSAvoidenergy recovery capability
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The brake system merges two different braking mechanisms: a friction brake mechanism for reliable mechanical braking and a regenerative brake mechanism for energy recovery. Both mechanisms are integrated into a unified brake system that leverages the strengths of each approach.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The brake system achieves multi-functionality by enabling the vehicle to both recover energy through regenerative braking and maintain reliable braking through the friction brake mechanism. The system can switch between or combine these functions based on operational conditions.

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

3Use of energy by moving object

If regenerative braking is used on the rear wheel, then energy efficiency is improved, but braking performance becomes insufficient under certain conditions

Engineering Contradiction:
Improveenergy efficiencyVSAvoidbraking performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The braking function is segmented between the front and rear wheels, with the friction brake mechanism dedicated to the front wheel and the regenerative brake mechanism dedicated to the rear wheel. This segmentation allows each mechanism to operate in its optimal performance range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies different braking parameters to different wheels: friction-based braking on the front wheel and regenerative braking on the rear wheel. This parameter differentiation ensures that energy efficiency is maintained through regenerative braking while braking performance reliability is ensured through the friction brake mechanism.

Inventive Principle:
Principle #35Parameter changes

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

Enhances safety by dynamically adjusting friction braking force on the front wheel, compensating for variations in regenerative torque, thereby maintaining consistent braking performance and improving vehicle stability.

Implementation Method 1

a friction brake mechanism that generates a friction braking force only on the front wheel

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a regenerative brake mechanism that uses rotary power of the rear wheel to make the electric motor function as a generator and generate regenerative torque

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4631802A1Brake system and saddle-riding type vehicle
Publication Date: 2025.10.15 ROBERT BOSCH GMBH
  • EP4631802A1 patent drawingFigure 1
  • EP4631802A1 patent drawingFigure 2~3
  • EP4631802A1 patent drawingFigure 4~5

AI summary

The invention has a purpose of providing a brake system for a straddle-type vehicle capable of improving safety of the straddle-type vehicle during braking. A brake system 100 for a two-wheeled motor vehicle 10 includes: a front-wheel brake mechanism 20 that brakes a front wheel 3; a rear-wheel brake mechanism 40 that brakes a rear wheel 4; and an operation element 11 operated by a rider. The front-wheel brake mechanism 20 includes a friction brake mechanism 21 that generates a friction braking force only on the front wheel 3, and can generate the friction braking force in response to motion of the operation element 11. The rear-wheel brake mechanism 40 does not include a friction brake mechanism but includes an electric motor 5 that generates a regenerative braking force on the rear wheel 4. The front-wheel brake mechanism 20 further increases or reduces the friction braking force by the friction brake mechanism 21 regardless of the motion of the operation element 11.