Straddle-Type Vehicle Brake Control Using Master Cylinder Pressure

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Solution Overview

Problem

Existing straddle-type vehicle safety systems lack accurate determination of braking operations and proper amplification of braking forces based on surrounding environment, leading to potential fluctuations against the rider's intention.

Innovation Solution

A controller system that includes an acquisition unit, determination unit, and execution unit to detect master cylinder pressures, determine braking operations, and amplify braking forces differentially between front and rear wheels based on surrounding environment information, ensuring accurate execution of a driving support mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a driving support mode amplifies braking force in straddle-type vehicles, then safety is improved, but fluctuations against the rider's intention may occur

Engineering Contradiction:
ImprovesafetyVSAvoidrider's intention alignment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs preliminary determination of braking operation status by comparing master cylinder pressures before executing braking force amplification. This preliminary action ensures the system understands the rider's intent before intervening, preventing fluctuations against the rider's intention while maintaining safety improvements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors both first and second master cylinder pressures and uses this feedback to dynamically adjust braking force amplification. By comparing the pressures and detecting changes, the system provides real-time feedback to maintain alignment with the rider's intention while improving safety through controlled amplification

Inventive Principle:
Principle #23Feedback

2Measurement precision

If master cylinder pressure is used to determine braking operation, then determination accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvebraking operation determination accuracyVSAvoidcontroller structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the existing master cylinder pressure signals already present in the braking system to determine braking operation status. By leveraging these self-existing signals without requiring additional sensors or complex measurement devices, the system achieves accurate determination while avoiding increased device complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The master cylinder pressure signals serve multiple functions: they both control the braking force application and provide information for determining braking operation status. This multi-functionality eliminates the need for separate determination mechanisms, maintaining system simplicity while achieving accurate measurement

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

Improves safety by accurately determining and amplifying braking forces in straddle-type vehicles, minimizing fluctuations against the rider's intention, and enhancing collision avoidance capabilities.

Implementation Method 1

a first master cylinder pressure corresponding to a pressure of a braking liquid of the first master cylinder; and a second master cylinder pressure corresponding to a pressure of a braking liquid of the second master cylinder

Methodology Applied
Scientific EffectHydraulic pressure transmission: Pascal's Law

Data Source

PatentEP4378767B1Controller for a straddle-type vehicle and control method for maneuvering a straddle-type vehicle
Publication Date: 2026.01.21 ROBERT BOSCH GMBH
  • EP4378767B1 patent drawingFigure 1
  • EP4378767B1 patent drawingFigure 2
  • EP4378767B1 patent drawingFigure 3~4

AI summary

To properly improve safety of a straddle-type vehicle. The controller includes a determination unit and an execution unit. The determination unit (63) determines, based on at least one of a first master cylinder pressure and a second master cylinder pressure, whether a braking operation is performed. The execution unit executes a driving support mode, in which a braking force generated in a straddle-type vehicle is amplified, when the determination unit determines that the braking operation is performed. The execution unit, in the driving support mode, amplifies: the braking force generated in the straddle-type vehicle, based on surrounding environment information about environment around the straddle-type vehicle; the braking force generated in the straddle-type vehicle with the amplification of the second wheel cylinder pressure superior to the amplification of the first wheel cylinder pressure when the rider performs the braking operation with the operation of the first braking operation unit superior to the operation of the second braking operation unit; and the braking force generated in the straddle-type vehicle with the amplification of the first wheel cylinder pressure superior to the amplification of the second wheel cylinder pressure when the rider performs the braking operation with the operation of the second braking operation unit superior to the operation of the first braking operation unit.