Electric Brake System Hydraulic Control for Regenerative Braking Stability
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Solution Overview
Problem
Conventional electric brake systems face instability and safety concerns due to technical malfunctions, particularly in hybrid vehicles where regenerative braking can affect wheel distribution, leading to oversteering, understeering, or sliding, and may not stably generate hydraulic pressure for braking.
Innovation Solution
An electric brake system with a hydraulic pressure supply device and a hydraulic control unit that includes multiple pressure chambers and valves to manage hydraulic pressure distribution to wheel cylinders, allowing for both low-pressure and high-pressure modes, and includes a simulation device to provide a reaction force and improve pedal feel, while also having backup paths for component redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If regenerative braking is used to recover kinetic energy during braking, then energy recovering rate increases, but braking force distribution to wheels becomes unstable causing oversteering, understeering, or sliding
Solution Approach 1:
The patent introduces a hydraulic control unit as an intermediary device between the regenerative braking system and the wheel cylinders. This unit includes multiple valves (first valve, second valve, third valve, fourth valve) that mediate and regulate the hydraulic pressure distribution to each wheel, ensuring stable braking force distribution even when regenerative braking is active. The hydraulic control unit acts as a buffer that decouples the instability of regenerative braking from the wheel braking forces.
2Reliability
If electric brake system components malfunction, then braking safety is threatened, but adding redundant components increases system complexity
Solution Approach 1:
The patent segments the hydraulic control system into multiple independent circuits and valves. The hydraulic control unit includes separate first and second hydraulic circuits, each with dedicated valves (first valve for first circuit, second valve for second circuit, third valve for first circuit, fourth valve for second circuit). This segmentation allows isolated malfunction of individual components without affecting the entire braking system, maintaining safety while avoiding excessive redundancy.
Solution Approach 2:
The patent implements beforehand cushioning by providing backup hydraulic pathways and redundant valve arrangements. The hydraulic control unit is designed with alternative flow paths and multiple valves that can compensate for potential component failures. This preemptive design ensures that even if one component malfunctions, the system can maintain braking functionality through the backup pathways.
3Reliability
If hydraulic pressure is not stably generated due to technical malfunction, then braking performance deteriorates, but increasing pressure generation capability increases energy consumption
Solution Approach 1:
The hydraulic control unit is designed to automatically regulate and stabilize hydraulic pressure without requiring additional energy input from the powertrain. The system uses passive hydraulic control mechanisms where the valves (first valve, second valve, third valve, fourth valve) automatically respond to pressure conditions and flow requirements, maintaining stable pressure generation through self-regulating hydraulic principles rather than active energy-consuming pumps or motors.
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 system ensures stable and efficient braking under various conditions, improves driving stability, and maintains performance even when components malfunction, reducing the risk of oversteering or understeering by uniformly distributing braking force across all wheels.
Implementation Method 1
a hydraulic pressure supply device configured to generate a hydraulic pressure by operating a hydraulic piston by an electrical signal output in response to displacement of a brake pedal
Implementation Method 2
a first valve provided at the second hydraulic flow path... to control a flow of a pressurized medium, a second valve provided at the third hydraulic flow path... to control a flow of the pressurized medium
Data Source
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AI summary
Disclosed herein are an electric brake system and several operating methods thereof. The electric brake system may include a hydraulic pressure supply device (100) to generate a hydraulic pressure by operating a hydraulic piston (114) in accordance with an electrical signal output in response to the displacement of a brake pedal (10), and a hydraulic control unit (200) comprising seven flow paths (211-217) to control a hydraulic pressure of the pressurized medium supplied to each wheel cylinder (40). The electric brake system may be operated in a normal mode, an abnormal mode and an inspection mode. Inventions are neither disclosed nor claimed.