Hydraulic Brake System with Redundant Pressure Generators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing brake systems for highly automated or autonomous vehicles are unsuitable as they rely on hydraulic intervention by a driver, which is not applicable in autonomous driving scenarios, and lack redundancy to ensure continuous braking performance in case of faults.
Innovation Solution
A hydraulic brake system with three pressure generators and a redundancy concept, featuring hydraulically separate sub-brake systems on each axle, where two are in series on the front axle and one on the rear, with no hydraulic connection between them, allowing for autonomous braking and facilitated mounting and reduced component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a traditional hydraulic brake system with driver intervention is used, then the system is simple and cost-effective, but it is unsuitable for highly automated or autonomous vehicles where no driver intervention is available
Solution Approach 1:
The brake system is divided into two hydraulically independent sub-brake systems (first and second brake circuits), each capable of independently providing braking force. This segmentation allows the system to function autonomously without driver intervention while maintaining relative simplicity through modular architecture.
2Reliability
If a redundant brake system with multiple pressure generators is implemented, then braking performance reliability is improved, but system complexity and cost increase
Solution Approach 1:
Redundancy is implemented locally rather than globally - the first brake circuit has two pressure generators (first and second) while the second brake circuit has one pressure generator. This localized redundancy approach ensures braking performance continuity while minimizing the total number of pressure generators and associated complexity.
Solution Approach 2:
The system incorporates redundant pressure generators beforehand to cushion against potential failures. If one pressure generator fails, others can compensate, ensuring continuous braking performance without requiring complex real-time fault detection and response systems.
3Reliability
If three pressure generators are used with a redundancy concept, then fault tolerance is improved, but hydraulic connections and components increase
Solution Approach 1:
The hydraulic system is segmented into two independent circuits, reducing the number of hydraulic connections required compared to a fully integrated three-pressure-generator system. Each circuit is hydraulically isolated, allowing fault tolerance without requiring extensive interconnections between all pressure generators.
4Ease of manufacture
If sub-brake systems are mounted separately on different axles, then mounting flexibility and assembly are facilitated, but hydraulic integration becomes more complex
Solution Approach 1:
The brake system is divided into two hydraulically independent sub-brake systems that can be mounted separately on different axles (front and rear). This segmentation facilitates manufacturing and assembly by allowing independent mounting while the hydraulic independence eliminates the need for complex inter-axle hydraulic connections.
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
Enables robust, cost-effective, and reliable braking performance without driver intervention, supports longer autonomous operation after faults, and simplifies manufacturing and installation by reducing hydraulic lines and components, while providing NVH advantages and lower system costs.
Implementation Method 1
a first pressure generator (12) which is assigned to the main system (10), a second pressure generator (22) which is assigned to the secondary system (20) and is connected hydraulically in series
Data Source
AI summary
The disclosure relates to a hydraulic brake system for a highly automated or autonomous vehicle which includes three pressure generators which provide sufficient braking force even in a case of a fault. Two of the pressure generators are assigned in a redundant manner to one axle and a modulation unit is configured to hydraulically connect the two pressure generators to the wheel brakes of the first axle, and to perform individual brake pressure modulation in the wheel brakes. The third pressure generator is hydraulically separate from the other pressure generators, and another modulation unit is configured to hydraulically connect the third pressure generator to wheel brakes of another axle, and to perform individual brake pressure modulation in the wheel brakes.