Vehicle Brake Actuator Failure Detection via Upstream Pressure
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Solution Overview
Problem
The existing vehicle braking device systems are costly due to the need for multiple hydraulic pressure sensors to detect abnormalities in the hydraulic actuator, which increases the overall cost and complexity.
Innovation Solution
A vehicle braking device that includes a braking actuator, a hydraulic pressure generation device, and an electronic control unit, where the hydraulic pressure sensor detects the upstream hydraulic pressure to determine failures without the need for sensors directly monitoring individual wheel cylinder pressures, allowing for cost-effective failure determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple hydraulic pressure sensors are used to detect abnormalities in the hydraulic actuator, then the reliability of abnormality detection is improved, but the device complexity and cost increase
Solution Approach 1:
The upstream hydraulic pressure sensor is designed to serve multiple functions: it monitors upstream pressure for actuator failure detection, provides feedback for normal braking control, and enables cost-effective abnormality detection without requiring separate sensors for each wheel cylinder, thus achieving multi-functionality that reduces overall system complexity
Solution Approach 2:
The control unit acts as an intermediary that processes upstream pressure sensor data to infer downstream abnormalities. Instead of directly monitoring each wheel cylinder with separate sensors, the system uses the upstream pressure changes as an indirect indicator of actuator failures, reducing sensor quantity while maintaining detection reliability
2Measurement precision
If multiple hydraulic pressure sensors are installed to monitor individual wheel cylinder pressures, then the measurement precision of brake system status is improved, but the manufacturing cost increases
Solution Approach 1:
The invention extracts the essential monitoring function from multiple individual wheel cylinder pressure sensors and consolidates it into a single upstream hydraulic pressure sensor. By taking out only the critical pressure monitoring point (upstream of the actuator), the system achieves adequate measurement precision for failure detection while significantly reducing manufacturing costs
Solution Approach 2:
The system uses a single, simpler upstream pressure sensor instead of multiple complex wheel cylinder pressure sensors. This approach prioritizes cost-effective monitoring by using fewer, more economical sensing elements that can reliably detect actuator failures through upstream pressure changes
3Device complexity
If a single upstream hydraulic pressure sensor is used instead of multiple wheel cylinder pressure sensors, then the device complexity is reduced, but the ability to directly detect wheel cylinder pressure abnormalities is worsened
Solution Approach 1:
The system implements feedback control by continuously monitoring upstream pressure changes and using this information to detect downstream abnormalities. The control unit analyzes upstream pressure variations that occur when the hydraulic actuator fails to properly regulate downstream pressure, enabling indirect but effective detection of wheel cylinder pressure issues
Solution Approach 2:
Instead of directly measuring downstream pressure at the wheel cylinders, the system inverts the approach by measuring upstream pressure and inferring downstream conditions from upstream changes. This reverse monitoring strategy reduces sensor requirements while maintaining the ability to detect actuator failures that affect downstream pressure
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 accurate failure determination of the braking actuator by maintaining and monitoring upstream hydraulic pressure, reducing the need for multiple sensors and lowering the system's cost while maintaining effective hydraulic pressure control.
Implementation Method 1
a hydraulic pressure sensor configured to detect the upstream hydraulic pressure
Implementation Method 2
a hydraulic pressure generation device connected to the braking actuator through a hydraulic pressure flow path and configured to execute increasing and maintaining an upstream hydraulic pressure supplied to the braking actuator
Implementation Method 3
a braking actuator configured to control a hydraulic pressure in a wheel cylinder
Data Source
AI summary
A vehicle braking device includes a braking actuator, a hydraulic pressure generation device, a hydraulic pressure sensor, and an electronic control unit. The electronic control unit is configured to execute an upstream pressure maintaining process of controlling the hydraulic pressure generation device to increase and maintain the upstream hydraulic pressure, a downstream pressurization process of controlling the braking actuator such that hydraulic fluid is supplied to the wheel cylinder through the hydraulic pressure flow path in a state in which the upstream hydraulic pressure is maintained, and a failure determination process of determining that a failure has occurred in the braking actuator in a case where the upstream hydraulic pressure is not decreased to be equal to or lower than a determination threshold value as the downstream pressurization process is executed.