Evasive Steering Torque Control for Understeering

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Solution Overview

Problem

Advanced driver assist systems often fail to effectively prevent accidents due to driver over-reaction during evasive maneuvers, leading to understeering on low-friction roads, which can result in collisions.

Innovation Solution

A method and system that detect a collision course with a target, assess user-initiated steering actions, and apply a counteracting steering torque overlay when understeering exceeds a threshold, ensuring the vehicle maintains stability and avoids the target by reducing excessive steering inputs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the driver steers sharply to avoid collision, then the vehicle may avoid the target, but the vehicle experiences understeering and loss of stability on low-friction roads

Engineering Contradiction:
Improvecollision avoidance effectivenessVSAvoidvehicle stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The system applies a counteracting steering torque before the driver's excessive steering input causes complete loss of vehicle control. By detecting understeering conditions and applying opposing torque through the steering control system, the system preemptively counteracts the harmful effect of over-steering, maintaining vehicle stability while still allowing collision avoidance maneuver completion

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system continuously monitors steering angle, vehicle speed, and road friction conditions to detect understeering. When understeering is detected, the system provides feedback by applying a counteracting steering torque through the steering control system, creating a closed-loop control that maintains vehicle stability during evasive maneuvers

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If the steering control system counteracts user-initiated steering action, then the degree of understeering is reduced, but the driver's intended steering input is partially opposed

Engineering Contradiction:
Improvevehicle stabilityVSAvoiddriver steering control
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The system applies only the necessary amount of counteracting steering torque to correct understeering, not to completely override the driver's input. The counteracting torque is calibrated to be sufficient to maintain vehicle stability and prevent complete loss of control, but not so strong as to prevent the driver from completing the evasive maneuver

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The steering control system dynamically adjusts the counteracting torque based on real-time detection of understeering conditions, vehicle speed, and road friction. The system applies counteracting force only when understeering is detected and releases it when the condition resolves, creating a dynamic response that adapts to changing driving conditions

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3626582B1Method and system for collision avoidance
Publication Date: 2023.08.09 POLESTAR PERFORMANCE
  • EP3626582B1 patent drawingFigure 1
  • EP3626582B1 patent drawingFigure 2a~2b
  • EP3626582B1 patent drawingFigure 2c~3

AI summary

The present invention relates to a method for collision avoidance for a host vehicle, the method comprising: detecting (S102) a target (104) in the vicinity of the vehicle; determining (S104) that the host vehicle is travelling on a collision course (106) with the target; detecting a user initiated steering action for steering the vehicle towards one side of the target; determining a degree of understeering of the host vehicle; when the degree of understeering exceeds a first understeering threshold, controlling a steering control system of the vehicle to counteract the user initiated steering action to thereby reduce the degree of understeering. The invention further relates to an evasive steering system.