Electrohydraulic Brake Control with Split Supply Line Redundancy
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Solution Overview
Problem
Existing brake systems for highly automated driving are costly and complex, with a need for a cost-effective and efficient electro-hydraulic brake control unit that can maintain essential braking functions even in the event of electrical failures.
Innovation Solution
An electro-hydraulic brake control unit with an electrically actuated pressure source, inlet and outlet valves for each wheel brake, and a circuit isolator valve that separates the brake supply line into two sections, allowing actuation by two pressure sources, with a minimal number of hydraulic connections and electrically actuated valves, ensuring redundancy and reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single brake control unit with one electrically actuated pressure source is used, then device complexity is reduced, but reliability decreases in case of electrical failures
Solution Approach 1:
The brake supply line is segmented into two line sections by the circuit isolator valve, allowing the first pressure source to serve at least two wheel brakes through the first line section while the second pressure source serves the remaining wheel brakes through the second line section. This segmentation enables redundancy without requiring a fully integrated complex system.
Solution Approach 2:
The circuit isolator valve acts as an intermediary component that enables the single brake control unit to function with multiple pressure sources by selectively isolating or connecting line sections. This intermediary allows the system to maintain simplicity while achieving the reliability benefits of multiple pressure sources.
2Reliability
If multiple electrically actuated valves and pressure sources are integrated in a single brake control unit, then reliability is improved, but manufacturing and assembly costs increase
Solution Approach 1:
The system segments the hydraulic circuit into two independent line sections that can be manufactured and assembled separately, then connected through the circuit isolator valve. This reduces the complexity of manufacturing a fully integrated multi-pressure-source unit while maintaining the reliability benefits.
Solution Approach 2:
The single brake control unit is designed with multi-functionality to serve multiple wheel brakes through two separate line sections controlled by one pressure source when needed, or isolated sections with different pressure sources when redundancy is required. This universal design reduces the need for completely separate control units.
3Reliability
If the circuit isolator valve is closed to separate line sections, then reliability is improved for fault isolation, but device complexity increases
Solution Approach 1:
The circuit isolator valve serves as a simple intermediary mechanism that provides fault isolation capability without significantly increasing overall system complexity. Its placement in the brake supply line allows it to separate the hydraulic circuit into two independent sections when closed, enabling fault isolation while maintaining a relatively simple overall architecture.
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 solution provides a cost-effective brake system that maintains essential braking functions even with electrical failures, supports highly automated driving, and reduces manufacturing and assembly costs by minimizing hydraulic and electrically actuated components.
Implementation Method 1
an electrically actuated pressure source, an electrically actuated inlet valve for each wheel brake, an electrically actuated outlet valve for each wheel brake, and a brake supply line
Implementation Method 2
An electrically actuated circuit isolator valve is arranged in the brake supply line such that, when the circuit isolator valve is closed, the brake supply line is hydraulically separated into a first line section and a second line section
Data Source
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AI summary
The invention relates to an electrohydraulic brake control device (200) for a motor vehicle for at least four hydraulically actuatable wheel brakes (8a-8d), said brake control device comprising: an electrically actuatable pressure source (2); an electrically actuatable inlet valve (6a-6d) for each wheel brake; an electrically actuatable outlet valve (7a-7d) for each wheel brake; and a brake supply line (13) to which the at least four inlet valves (6a-6d) are connected, an electrically actuatable circuit separating valve (40) being positioned in the brake supply line (13) in such a way that, when the circuit separating valve (40) is closed, the brake supply line (13) is hydraulically separated into a first line section (13a) and a second line section (13b), the brake control device (200) comprising at least four hydraulic wheel connections (9a-9d) for connection to the wheel brakes (8a-8d), the brake control device (200) comprising a first hydraulic connection (62) for connection to a pressure fluid reservoir (4) and a second hydraulic connection (61) for connecting a further pressure source (5) to the brake control device (200), the first line section (13a) of the brake supply line (13) being hydraulically connected to the electrically actuatable pressure source (2) and at least two of the at least four inlet valves (6a, 6b), and the second line section (13b) of the brake supply line (13) being hydraulically connected to the second hydraulic connection (61) and the other of the at least four inlet valves (6c, 6d). The invention also relates to a brake system for a motor vehicle comprising such a brake control device (200).