One-Side Brake Torque Distribution for Steering Failure Control
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Solution Overview
Problem
Existing steering and braking systems in automobiles, particularly in By-Wire technologies, lack a redundancy mechanism to ensure stable vehicle control when a steering system failure occurs, leading to potential accidents and instability during one-side braking.
Innovation Solution
A one-side brake control system that distributes torques between front and rear wheels, using an integrated ECU to calculate target moments and brake torques, and a braking ECU to control actuators for stable emergency steering by adjusting brake pressures and torques based on the vehicle's target steering angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If one-side brake is applied to a rear wheel only, then emergency steering capability is provided, but rotational force causes unstable steering control
Solution Approach 1:
The braking system is segmented into four independent wheel brake controls, allowing selective application of brake force to specific wheels. During emergency steering, the system segments the braking action by applying force only to wheels on one side of the vehicle, creating a yaw moment for directional control while maintaining overall system stability through coordinated wheel-level control.
Solution Approach 2:
The system applies brake force locally to specific wheels based on the required emergency steering direction. By applying brake force only to the left or right wheels (local application) rather than all wheels uniformly, the system generates the necessary rotational moment for emergency steering while minimizing unwanted pitch phenomena and maintaining steering control stability.
2Reliability
If one-side brake force is applied to generate vehicle moment, then emergency steering is enabled, but pitch phenomenon and wheel slip occur
Solution Approach 1:
The system dynamically adjusts brake force parameters (magnitude and distribution) based on real-time vehicle state and road conditions. By optimizing the brake force applied to each wheel, the system generates sufficient yaw moment for emergency steering while preventing excessive brake force that would cause pitch phenomenon or wheel slip, thus eliminating harmful side effects.
Solution Approach 2:
The braking control system incorporates feedback mechanisms that monitor wheel speed, vehicle acceleration, and brake force application. This feedback allows the system to detect early signs of pitch phenomenon or wheel slip and automatically adjust the brake force distribution to prevent these harmful effects while maintaining effective emergency steering capability.
3Reliability
If brake pressure is applied to rear wheel only, then one-side brake force is generated, but additional brake force cannot be applied when pressure reaches limit
Solution Approach 1:
The system transitions from single-wheel brake control to multi-dimensional wheel-level brake control. By independently controlling brake force on up to four wheels (front-left, front-right, rear-left, rear-right), the system creates additional control dimensions that allow continuous adjustment of total brake force and distribution, enabling both sufficient one-side brake force generation and extended adaptability for various emergency situations.
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 stable emergency steering and prevents wheel slip by dynamically adjusting brake torques and pressures between front and rear wheels, ensuring safe vehicle maneuvering during steering system failures.
Implementation Method 1
a braking actuator of one-side front wheel and one-side rear wheel of the vehicle according to the brake torque values of the front wheel and the rear wheel transmitted from the integrated ECU to perform one-side brake
Data Source
AI summary
A one-side brake control system and method perform distribution of torques between front and rear wheels. The one-side brake control system includes a target steering angle input unit to which a target steering angle of a driver or a controller of an autonomous vehicle is input when a steering system fails, an integrated Electronic Control Unit (ECU) configured to calculate a target moment of the vehicle according to the target steering angle input through the target steering angle input unit and calculate brake torques of a one-side front wheel and a one-side rear wheel of the vehicle based on the target moment, and a braking ECU configured to control one or more braking actuators of the one-side front wheel and the one-side rear wheel of the vehicle according to the brake torque of the front wheel and the rear wheel transmitted from the integrated ECU to perform one-side brake.