Brake Control System Modulating Wheel Slip for Peak Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The efficacy of braking systems in wheeled vehicles is limited by the variability of the ground/wheel interface friction, which is influenced by factors such as road conditions, tire condition, and wheel slip, leading to unstable braking performance.
Innovation Solution
A system that monitors wheel slip and modulates braking power to maintain peak friction by introducing a dither component, adjusting the nominal braking power based on the volatility of the monitored wheel slip to operate at maximal braking power, thereby maintaining stability and preventing skidding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If braking power is increased to improve braking performance, then braking efficacy is improved, but wheel slip increases causing friction to decrease and stability to worsen
Solution Approach 1:
The system dynamically adjusts braking power based on real-time wheel slip monitoring. The controller continuously modulates the braking force to maintain optimal wheel slip conditions, transitioning from static braking application to dynamic control that adapts to changing road conditions and wheel behavior.
Solution Approach 2:
The system implements closed-loop feedback control by monitoring wheel slip and using this information to adjust braking power. The controller receives feedback on actual wheel slip conditions and modifies the braking force accordingly to maintain peak friction and prevent wheel lockup.
2Power
If wheel slip is increased to achieve maximal braking power, then braking power is improved, but friction variability increases leading to unstable braking performance
Solution Approach 1:
The system uses continuous feedback from wheel slip monitoring to maintain consistent braking performance. By comparing actual wheel slip against target values and adjusting braking force in response, the system achieves reliable and repeatable braking performance across varying road conditions.
Solution Approach 2:
The system changes the wheel slip parameter dynamically during braking operation. Instead of maintaining zero wheel slip or allowing uncontrolled slip, the controller actively manages wheel slip as a controllable parameter to optimize the friction characteristics and maintain consistent braking performance.
3Speed
If braking force is applied to stop the vehicle, then stopping capability is improved, but wheel lockup occurs reducing braking effectiveness
Solution Approach 1:
The system dynamically controls braking force application to prevent wheel lockup while maintaining effective deceleration. Rather than applying maximum static braking force that causes lockup, the controller continuously adjusts the braking force to keep wheels rotating just below lockup conditions, optimizing both deceleration and braking power utilization.
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 approach allows for near-maximal braking power by maintaining optimal wheel slip, reducing the likelihood of wheel lockup and enhancing braking stability across varying road conditions.
Implementation Method 1
The efficacy of a braking system is therefore limited by this ground/wheel interface. The friction of the ground/wheel interface can depend on many factors.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Apparatus and associated methods relate to controlling a brake mechanism during braking operation to provide near-maximal braking power. Maximal braking power occurs at when the wheel slip has a target value. Wheel slip can be monitored during braking operation so as to be used in control the brake mechanism to operate at the maximal braking power. The braking power is modulated so as to dither the braking power about a nominal braking power. The monitored wheel slip will have a dither component in response to the dithering of the braking power. A volatility of the dither component of the monitored wheel slip can be indicative of nominal braking power proximity to the maximal braking power. A nominal brake signal can be generated so as to change the nominal braking power in the direction of the maximal braking power based on the volatility of the dither component of the monitored wheel slip.