Electropneumatic Brake Backup Valve for Fast Fault Redundancy

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Solution Overview

Problem

Existing electropneumatic service brake systems in vehicles with automated driving functions require rapid redundancy in brake control to maintain functionality in case of faults, but current solutions are costly and inefficient in terms of installation space and weight, and do not provide immediate response during failures.

Innovation Solution

An electropneumatic service brake system with a secondary electronic brake control device that generates pneumatic brake control pressure independently of the primary electrical system, ensuring rapid redundancy by pre-generating pneumatic control pressure before electrical failures occur, using an electromagnetic backup valve and solenoid valve device to quickly switch to pneumatic control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complete redundancy of all components of the electropneumatic service brake system is implemented, then functionality is maintained even if a fault occurs, but costs, installation space and weight increase significantly

Engineering Contradiction:
Improvebrake system functionalityVSAvoidsystem redundancy
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent pre-generates pneumatic brake control pressure in a second storage chamber before any fault occurs. This preliminary action ensures that when the electrical service brake circuit fails, the pre-stored pneumatic pressure can immediately take over without requiring time-consuming generation or evaluation, thus maintaining brake functionality without needing complete system redundancy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the critical function of brake pressure generation from the electrical control system by providing a separate pneumatic service brake circuit with pre-generated pressure. This separation allows the pneumatic system to independently maintain brake functionality when the electrical system fails, reducing the need for redundant electrical components

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If evaluation of switching condition and flow of brake control pressure is required in the event of defect, then a certain amount of time is consumed, but rapid response is required to generate wheel brake pressure

Engineering Contradiction:
Improvefault compensation speedVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system continuously maintains pneumatic brake control pressure in the second storage chamber before any fault occurs. When a defect is detected, the electromagnetic backup valve immediately directs the pre-generated pressure to the wheel brake actuators, eliminating the time required for pressure generation and evaluation during the fault response

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent bypasses the normal evaluation and generation process by having pneumatic pressure already available in the second storage chamber. Upon detecting a fault, the system rushes through the failover by immediately directing pre-stored pressure to the actuators, skipping the time-consuming steps of pressure generation and system evaluation

Inventive Principle:
Principle #21Skipping (Rushing through)

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

Ensures rapid and reliable brake pressure generation in case of electrical failures, maintaining vehicle control functions like ABS and ESP, reducing the need for complete system redundancy and minimizing actuator wear.

Implementation Method 1

an electromagnetic backup valve which is connected to the pneumatic control input and which is designed and controlled such that it retains the at least one pneumatic brake control pressure (p1, p2) if the at least one electrical service brake circuit is intact, but otherwise, if the at least one electrical service brake circuit has a defect, passes the at least one pneumatic brake control pressure (p1, p2)

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 2

controls at least one electrically operated actuator by a second electrical brake request signal (S2), which is designed to generate at least one pneumatic brake control pressure (p1, p2) on the basis of the second electrical brake request signal (S2)

Methodology Applied
Scientific EffectPneumatic pressure control: Pressure Gradient

Data Source

PatentEP4347336B1Electropneumatic equipment for a vehicle with an autonomous brake circuit supplied with backup pressure as a precaution
Publication Date: 2025.07.09 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP4347336B1 patent drawingFigure 1
  • EP4347336B1 patent drawingFigure 2
  • EP4347336B1 patent drawingFigure 3

AI summary

The invention relates to electric equipment for a vehicle with an electropneumatic service brake device (80), wherein at least one pneumatic brake control pressure (p1, p2) is immediately and directly controlled to the electromagnetic backup valve, which is still being closed by a current, of at least one pressure regulating module (20) in response to an assistance brake request signal (AS) regardless of a defect of an electric service brake circuit. In the event of a failure of the electric service brake circuit, the electromagnetic backup valve, which is then in the currentless state, of the at least one pressure regulating module (20) is then automatically opened, and the brake pressure is immediately formed in the pressure regulating module (20) in question on the basis of the at least one pneumatic brake control pressure (p1, p2) already present in the pressure regulating module. In this manner, the reaction time of a pneumatic redundancy of the electropneumatic service brake device (80) in response to electric defects is reduced.