Vehicle Brake Control System Torque Management

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Solution Overview

Problem

Conventional vehicle brake control systems experience delays in frictional braking response, leading to slower deceleration when regenerative braking is discontinued, causing discomfort to drivers due to inadequate rapid application of frictional braking force.

Innovation Solution

A control apparatus that initiates both regenerative and frictional braking from the initial stage of braking, using a braking detector to determine the braking stage and adjust torque levels to minimize delays, ensuring a combination of limited regenerative and supplemental frictional braking torques to maintain target braking torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If regenerative braking is used solely during the initial stage of braking, then energy efficiency is improved and fuel consumption is reduced, but response delay occurs when frictional braking is applied later causing driver discomfort

Engineering Contradiction:
Improveenergy efficiencyVSAvoidresponse delay
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The master cylinder is designed with a preliminary action mechanism where the piston initially moves to open a fluid communication port before blocking it. This preliminary opening of the port allows brake fluid to flow in advance, eliminating the response delay when frictional braking is applied. The piston's initial movement prepares the fluid pathway before the actual braking force is needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The braking system is segmented into distinct phases: an initial phase where the piston moves to open the fluid port for advance fluid communication, and a subsequent phase where the piston blocks the port to generate full braking pressure. This segmentation allows the system to prepare fluid pathways in advance while maintaining energy efficiency through regenerative braking during the initial phase.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If frictional braking is applied from the initial stage alongside regenerative braking, then response delay is reduced, but energy efficiency decreases and fuel consumption increases

Engineering Contradiction:
Improveresponse delayVSAvoidenergy efficiency
Core Design Contradiction:
Loss of timeVSUse of energy by moving object

Solution Approach 1:

The system uses preliminary action by opening the fluid communication port in advance through initial piston movement, allowing frictional braking to be ready to engage immediately when needed. This eliminates response delay without requiring continuous frictional braking from the initial stage, thereby maintaining energy efficiency by relying on regenerative braking during the initial phase.

Inventive Principle:
Principle #10Preliminary action

3Force

If the master cylinder piston moves directly to block the fluid port, then braking force is generated, but response delay occurs before sufficient fluid pressure is generated

Engineering Contradiction:
Improvebraking forceVSAvoidresponse delay
Core Design Contradiction:
ForceVSLoss of time

Solution Approach 1:

The piston performs a preliminary action by initially moving to open the fluid communication port before blocking it. This preliminary movement establishes fluid pathways in advance, so that when the piston subsequently blocks the port to generate braking force, the fluid pressure builds up immediately without delay. The preliminary opening of the port prepares the system for rapid pressure generation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The piston movement is segmented into two distinct actions: first moving to open the fluid port for advance fluid communication, then blocking the port to generate braking pressure. This segmentation ensures that fluid pathways are prepared in advance, eliminating the time delay between piston movement and sufficient pressure generation while maintaining effective braking force.

Inventive Principle:
Principle #1Segmentation

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

This approach reduces response delays in frictional braking, maintaining smooth deceleration and energy efficiency by compensating for regenerative braking shortfalls with high-response regenerative braking, even when regenerative torque drops to zero, enhancing driver comfort and energy recovery.

Implementation Method 1

a regenerative braking system of the vehicle to provide a limited braking torque

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a frictional braking system of the vehicle to provide a first supplemental braking torque

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2560850B1Vehicle brake control system
Publication Date: 2016.09.14 NISSAN MOTOR CO LTD
  • EP2560850B1 patent drawingFigure 1
  • EP2560850B1 patent drawingFigure 2
  • EP2560850B1 patent drawingFigure 3

AI summary

A vehicle brake control system comprises a braking detector component (26, 27) and a braking controller (5, 8, 14). The braking detector component (26, 27) determines whether a braking operation in a vehicle (V) is within an initial braking stage based on a control condition of a frictional braking system (9R, 9L, 10R, 10L, 13). The braking controller component (5, 8, 14) performs initial braking stage control during the initial braking stage by controlling a regenerative braking system (3, 4, 5, 6, 7) to provide a limited braking torque and the frictional braking system (9R, 9L, 10R, 10L, 13) to provide a supplemental braking torque, the combination of which provides a target braking torque. The braking controller component (5, 8, 14) performs subsequent braking control when the initial braking stage ends to provide an increased regenerative braking torque and a lower supplemental braking torque as the target braking torque.