Integrated Brake Pressure Control for Redundant Hydraulic Braking
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Solution Overview
Problem
Existing brake systems for semi-automated and fully automated driving face challenges in ensuring reliable pressure supply and redundancy without complex valve designs, which can lead to brake failures due to dormant faults and packaging constraints, particularly in systems with multiple pressure supplies.
Innovation Solution
A compact, modular 1-box solution integrating a pressure supply unit, solenoid valves, electronic control unit, reservoir, and pedal stroke sensors, with redundant components and fail-safe designs to ensure fault tolerance and efficient packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a redundant pressure supply system with multiple pressure supplies is used to ensure braking force build-up, then reliability is improved, but device complexity and packaging volume increase
Solution Approach 1:
The patent combines multiple pressure supplies into a single integrated pressure supply unit that can provide redundant braking force build-up capability. The control unit manages the single pressure supply to perform both primary and backup braking functions, eliminating the need for physically separate redundant pressure supplies while maintaining reliability.
Solution Approach 2:
The single pressure supply unit is designed to serve multiple functions: it acts as both the primary pressure supply for normal braking operations and the backup pressure supply for emergency situations. The control unit enables this multi-functionality by dynamically managing the pressure supply based on system state and failure conditions.
2Reliability
If a tandem master cylinder is used to ensure redundant pressure supply, then reliability is improved, but packaging volume increases
Solution Approach 1:
The patent merges the functions of two separate master cylinders into a single master cylinder unit. The control unit manages this single cylinder to provide pressure for both brake circuits, eliminating the need for a second physical master cylinder while maintaining redundant pressure supply capability through electronic control.
Solution Approach 2:
The patent replaces the mechanical redundancy of a tandem master cylinder with an electronically controlled single master cylinder system. The control unit uses electronic signals and solenoid valves to manage pressure distribution, substituting mechanical dual-cylinder redundancy with electronic control logic.
3Reliability
If complex valve designs are used to ensure pressure control, then reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent uses solenoid valves that can be precisely manufactured using standardized electromagnetic actuator designs. Instead of complex mechanical valve mechanisms, the system employs electrically actuated valves that replicate reliable electromagnetic switching technology, simplifying manufacturing while maintaining precise pressure control reliability.
Solution Approach 2:
The patent replaces complex mechanical pressure control mechanisms with electronically controlled solenoid valves. The electromagnetic actuation provides precise and reliable valve control with simpler manufacturing requirements compared to traditional mechanical linkage or cam-based pressure control systems.
4Reliability
If multiple pressure supplies are used for automated driving levels 4 and 5, then reliability is improved, but packaging constraints are worsened
Solution Approach 1:
The patent combines multiple pressure supply functions into a single compact pressure supply unit. The control unit manages this unified system to provide redundant pressure capability for automated driving operations, significantly reducing the packaging volume required compared to physically separate multiple pressure supplies.
Solution Approach 2:
The single pressure supply unit is designed to perform multiple functions required for automated driving levels 4 and 5, including normal braking, emergency braking, and backup pressure supply. This multi-functionality is achieved through electronic control that dynamically allocates the single pressure supply to different functions based on system needs.
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, compact, and reliable braking system that maintains functionality even with component failures, meeting safety and packaging requirements for automated driving levels 2 to 5.
Implementation Method 1
a pressure supply unit DV1, in particular an electric motor (2) which can drive a piston (8) in a cylinder (7)
Implementation Method 2
at least one valve assembly (HCU) with solenoid valves for wheel-specific pressure control
Implementation Method 3
the working chamber is hydraulically connected or connectable to a reservoir (VB) and a pedal feel simulator
Data Source
Figure 1
Figure 1a~1c
Figure 2~2a
AI summary
The invention relates to an actuating device for a fully or partially hydraulically actuated braking system for a vehicle, comprising a master brake cylinder (HZ) with a piston-cylinder unit having a piston and a working chamber, wherein the working chamber is hydraulically connected or connectable to a reservoir (VB) and a pedal feel simulator and is mechanically connected via an actuating device, in particular a brake pedal, and the working chamber is connectable to at least one brake circuit (BK1, BK2) via at least one normally open valve (FV), and that at least one hydraulically actuated wheel brake (RB) assigned to a brake circuit (BK1, BK2) is assigned to each of which at least one controllable switching valve (SV) is assigned, with which the wheel brake (RB) can be connected to the respective brake circuit (BK1, BK2) for pressure build-up (pauf) and pressure release (pab), in particular in brake air booster operation.wherein a pressure supply (DV1) driven by an electric motor (2), the piston of which is adjustable in the cylinder by means of the electric motor (2), and at least one valve arrangement (HCU) with solenoid valves for wheel-specific pressure control, as well as at least one electrical control unit (ECU) for controlling at least valves of the valve arrangement (ECU) and the motor of the pressure supply (DV!), wherein at least one controlled outlet valve (AV), through which hydraulic medium can be directly discharged, especially in normal operation (ABS), from the respective wheel brake (RB) or the brake circuit (BK1, BK2) into the reservoir (VB), and wherein the valve arrangement (ECU) and the hydraulic component of the pressure supply (DV) are arranged in a housing (A) and the master brake cylinder (HZ) is arranged in a separate housing (C).