Vehicle Braking System with Dynamic Boost Force Adjustment

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Solution Overview

Problem

Existing vehicle braking systems lack efficient mechanisms to seamlessly transition between normal and emergency braking modes, leading to unpredictable pedal feedback and potential loss of driver confidence during hydraulic braking assist routines.

Innovation Solution

An electronically-controlled booster system that senses driver input and adjusts boost force in conjunction with a hydraulic braking assist routine, reducing boost force during emergency braking to maintain pedal feel and ensure maximum braking force without perceptible changes to the driver.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the pump is activated to provide assisting wheel braking force during emergency braking, then maximum braking force is achieved, but the boost force from the electronically-controlled booster creates unpredictable pedal feedback

Engineering Contradiction:
Improvebraking forceVSAvoidpedal feedback consistency
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The controller continuously monitors the braking state and dynamically adjusts the boost force based on real-time conditions. During the hydraulic braking assist routine, the controller reduces the boost force in response to pump activation, creating a closed-loop feedback system that maintains consistent pedal feedback while achieving maximum braking force.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The electronically-controlled booster dynamically adjusts its boost force output during different braking phases. The system transitions from normal boost levels during routine braking to reduced boost levels during hydraulic braking assist routine, allowing the system to adapt its characteristics to maintain predictable pedal feedback across varying operating conditions.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the boost force is reduced during the hydraulic braking assist routine, then consistent pedal feedback is maintained, but the overall braking assist capability may be compromised

Engineering Contradiction:
Improvepedal feedback consistencyVSAvoidbraking assist force
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The system utilizes the hydraulic pump to provide the primary braking assist force during emergency braking events. By activating the pump to deliver hydraulic pressure directly to the wheel cylinders, the system compensates for the reduced electronic booster output, ensuring maximum braking force is achieved while maintaining consistent pedal feedback through coordinated hydraulic assistance.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Force

If the electronically-controlled booster provides maximum boost force during emergency braking, then maximum braking force is achieved, but driver confidence is reduced due to perceptible changes in pedal feel

Engineering Contradiction:
Improvebraking forceVSAvoiddriver confidence
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The system changes the operational parameters of the electronically-controlled booster during emergency braking events. By reducing the boost force parameter during the hydraulic braking assist routine, the system maintains a consistent pedal feel that preserves driver confidence, while the hydraulic pump compensates to ensure maximum braking force is still achieved for safe vehicle stopping.

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

The system enhances driver confidence and satisfaction by maintaining consistent pedal feedback during emergency braking, ensuring effective vehicle deceleration while preventing wheel lockup and skidding through proportional force adjustments.

Implementation Method 1

A pump is operable to pump fluid toward the wheel cylinder to provide an assisting wheel braking force

Methodology Applied
Scientific EffectHydraulic fluid pumping: Pump

Implementation Method 2

The total output force is conveyed through hydraulic fluid from the master cylinder to at least one wheel cylinder to providing a vehicle braking force

Methodology Applied
Scientific EffectHydraulic pressure transmission: Hydraulic Press

Data Source

PatentEP3554902B1Vehicle braking system and method
Publication Date: 2020.08.19 ROBERT BOSCH GMBH
  • EP3554902B1 patent drawingFigure 1
  • EP3554902B1 patent drawingFigure 2

AI summary

A vehicle braking system includes a brake pedal (32), a master cylinder (28), and an electronically-controlled booster (B) having an input member and an output member adapted to provide an input force to the master cylinder that combines a driver-supplied input force and a boost force provided by the electronically-controlled booster. A wheel cylinder (36) is fluidly coupled to an outlet of the master cylinder (28) and operable to provide a wheel braking force proportional to the input force to the master cylinder. A pump (60-1,60-2) is operable to pump fluid toward the wheel cylinder to provide an assisting wheel braking force. A controller (40) is programmed to trigger a hydraulic braking assist routine in which the pump is activated to provide the assisting wheel braking force. The controller is programmed to reduce the boost force provided by the electronically-controlled booster during the hydraulic braking assist routine.