Steering Torque and Differential Braking in High-Speed Lane Evasion
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Solution Overview
Problem
Existing driver aid systems, such as automatic emergency braking and evasive steering, are ineffective in high-speed collision avoidance scenarios, particularly when a vehicle is traveling at high speed and must change lanes to avoid obstacles, as they fail to manage vehicle controllability and stability limits.
Innovation Solution
A method and system that dynamically control steering and differential braking systems to plan and execute obstacle-avoidance paths, with constraints on steering torque and vehicle stability, using a closed-loop controller and feedforward compensation to ensure safe maneuvering by limiting slip and yaw rate, and activating differential braking when necessary to assist steering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the steering torque demanded by the AES controller is increased to improve avoidance performance, then the obstacle avoidance capability is improved, but the driver's ability to take back manual control is compromised and vehicle stability is endangered
Solution Approach 1:
The patent applies dynamics by making the steering system adjustable and adaptable during operation. The AES controller dynamically adjusts steering torque demands based on real-time vehicle state monitoring, ensuring that torque remains within safe limits while maintaining avoidance effectiveness. This allows the system to transition between different control modes smoothly, preserving driver recoverability while achieving avoidance goals.
Solution Approach 2:
The patent implements feedback through continuous monitoring of vehicle dynamics parameters (drift angle, yaw rate, slip) and steering torque levels. This feedback loop allows the AES controller to adjust steering commands in real-time, preventing excessive torque that would compromise driver control while maintaining effective avoidance performance. The system constantly checks vehicle state and modifies control actions accordingly.
2Reliability
If the vehicle performs a sharp avoidance maneuver at high speed to improve collision avoidance, then the obstacle avoidance capability is improved, but the vehicle stability is compromised due to loss of grip between tire and ground
Solution Approach 1:
The patent applies preliminary action by pre-defining multiple avoidance paths with varying characteristics (sharp avoidance, moderate avoidance, gentle avoidance) before the maneuver is executed. The system evaluates vehicle conditions and selects the appropriate pre-planned path that maintains stability while achieving avoidance. This prevents excessive sharpness that would cause loss of grip.
Solution Approach 2:
The patent changes parameters by adjusting steering torque limits, drift angle thresholds, and yaw rate constraints based on vehicle operating conditions (speed, road surface, vehicle state). These parameter adjustments allow the system to perform effective avoidance maneuvers while maintaining vehicle stability by adapting the maneuver intensity to current conditions.
3Productivity
If the differential braking system is combined with the steering system to improve vehicle handling at high speed, then the vehicle handling dynamics are improved, but the system complexity increases
Solution Approach 1:
The patent merges the steering system and differential braking system into a unified AES controller that coordinates both actuators. This combination allows the system to leverage the strengths of each system (steering effectiveness at moderate speeds, braking effectiveness at high speeds) while managing them through a single integrated control logic, improving handling without proportionally increasing complexity.
Solution Approach 2:
The patent creates a universal AES controller that performs multiple functions: path planning, steering control, differential braking control, and vehicle stability monitoring. This multi-functional controller consolidates what could be separate complex systems into one coordinated unit, achieving superior handling dynamics while managing system complexity through functional integration.
Data Source
AI summary
An obstacle-avoidance method includes detecting an obstacle in a vicinity of a motor vehicle and planning an obstacle-avoidance path for avoiding the obstacle; and commanding steering and differential braking systems to handle the avoidance path.