Vehicle Braking System Yaw-Moment Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle braking systems face challenges in accurately controlling brake pressure during yaw-moment control, particularly when the slave cylinder is operated at the start of yaw-moment control, leading to reduced accuracy and responsiveness due to the addition of low braking force from the slave cylinder.
Innovation Solution
A vehicle braking system incorporating a hydraulic-pressure generation device and a vehicle-behavior stabilization device, with control units that manage hydraulic pressure to finely control braking force, allowing for the generation or reduction of predetermined hydraulic pressure to stabilize vehicle behavior, and a second control unit that generates a braking force lower than the stabilization device, enabling precise control by forbidding or reducing hydraulic pressure generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the slave cylinder is operated at the start of yaw-moment control to generate hydraulic pressure, then the initial responsiveness of brake pressure is improved, but the accuracy of yaw-moment control is lowered
Solution Approach 1:
The braking system is divided into two independent pathways: a slave cylinder for rapid initial pressure generation and a vehicle-behavior stabilization device for precise control. The slave cylinder provides quick initial responsiveness, while the stabilization device takes over for accurate yaw-moment control, segmenting the functions to resolve the contradiction between speed and precision.
Solution Approach 2:
The function of precise yaw-moment control is extracted from the slave cylinder and assigned to the vehicle-behavior stabilization device. The slave cylinder is reserved solely for initial responsiveness, while the stabilization device handles accurate pressure regulation, separating the conflicting requirements into different components.
2Speed
If the slave cylinder generates brake pressure in advance, then the responsiveness of braking force application is improved, but the ability to finely control brake pressure is reduced
Solution Approach 1:
The braking control is segmented into two phases: initial rapid pressure generation by the slave cylinder, and subsequent fine-tuned pressure control by the vehicle-behavior stabilization device. This segmentation allows the system to achieve both rapid responsiveness and precise pressure control.
Solution Approach 2:
The vehicle-behavior stabilization device acts as an intermediary between the slave cylinder and the wheel cylinders. It receives the initial pressure from the slave cylinder and precisely regulates it before delivering to the wheels, enabling fine control while maintaining responsiveness.
3Stability of the object's composition
If a relatively small braking force is used for yaw-moment control, then the vehicle behavior stability is improved, but the accuracy of brake pressure control is lowered when slave cylinder pressure is added
Solution Approach 1:
The function of precise pressure control is extracted from the slave cylinder and assigned to the vehicle-behavior stabilization device. This allows the slave cylinder to provide stable but imprecise initial pressure, while the stabilization device provides the precise control needed for accurate yaw-moment regulation.
Solution Approach 2:
The system changes the control parameter from direct slave cylinder pressure control to stabilization device-mediated pressure control. The stabilization device adjusts pressure parameters precisely, enabling accurate control even when the slave cylinder provides only small braking forces for stability.
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
This system allows for precise control of braking force to stabilize vehicle behavior, improving the accuracy and responsiveness of yaw-moment control by adjusting hydraulic pressure generation in response to vehicle conditions.
Implementation Method 1
a hydraulic-pressure generation device which communicates with a master cylinder and generates a braking force with hydraulic pressure by an electrical actuator
Implementation Method 2
a vehicle-behavior stabilization device which communicates with the hydraulic-pressure generation device and generates a braking force for stabilizing vehicle behavior
Data Source
AI summary
In a vehicle braking system for stabilizing vehicle behavior: a motor control unit determines whether or not the motor control unit receives a drive forbid signal from a yaw-moment control unit, when the motor control unit receives a drive instruction signal from a vehicle-behavior stabilization control unit. The motor control unit receives the drive forbid signal when the yaw-moment control unit performs yaw-moment control. The motor control unit forbids prepressurization using a slave cylinder, when the motor control unit receives the drive forbid signal.