Steering Reaction Force Decoupling for Lane Deviation Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing in-lane drive assist devices fail to maintain consistent vehicle behavior due to variations in steering retention force from drivers, leading to unintended vehicle behavior when attempting to correct lane deviations.
Innovation Solution
The system controls the turning amount of a mechanically detached turning unit based on the steering amount when no lane deviation is present and generates a yaw moment to return the vehicle into the lane, while controlling the steering reaction force without reflecting the drive assist turning amount, thereby isolating it from the steering retention force when a deviation occurs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the assisting force is increased to return the vehicle into the lane, then the lane deviation correction is improved, but the turning angle fluctuates due to steering retention force resulting in unintended vehicle behavior
Solution Approach 1:
The patent segments the steering system into a steering unit (steering wheel) and a turning unit (front wheels), mechanically detaching them. This allows independent control of the turning unit based on lane deviation detection, while the steering unit responds only to driver input, eliminating the interference of steering retention force on automated correction accuracy.
Solution Approach 2:
The patent introduces a controller as an intermediary that receives lane deviation information from a lane recognition system and independently determines turning commands for the turning unit. This intermediary decouples the automated lane correction function from the driver's steering retention force, ensuring reliable and stable vehicle behavior.
2Measurement precision
If the turning unit is mechanically detached from the steering unit, then the turning angle control accuracy is improved, but the steering reaction force does not reflect the drive assist turning amount causing driver discomfort
Solution Approach 1:
The controller acts as an intermediary that generates two separate control signals: one for the turning unit (based on lane deviation) and one for the steering reaction force (based on drive assist turning amount). This allows the system to maintain both high turning precision and natural steering feedback for driver comfort.
Solution Approach 2:
The patent applies different control qualities to different parts of the steering system: the turning unit receives precise, automated control signals for accurate lane keeping, while the steering unit receives reaction forces that simulate natural steering characteristics, providing locally optimized performance for each component.
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 ensures the intended vehicle behavior is achieved regardless of the driver's steering retention force, reducing driver discomfort and maintaining stable vehicle alignment by decoupling the steering reaction force from the drive assist turning amount during lane correction.
Implementation Method 1
a reaction force motor 8 that generates a steering reaction force torque to apply steering reaction force to the steering wheel 6
Implementation Method 2
a turning motor 13 that generates a turning torque to turn the front wheels 5L, 5R
Implementation Method 3
a backup clutch 3 that mechanically connects the steering unit 1 and the turning unit 2 when a failure occurs in the SBW system
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Upon controlling the turning angle of the front wheels 5L, 5R which are mechanically detached from the steering wheel 6, the turning angle of the front wheels 5L, 5R is controlled based on the SBW command turning angle corresponding to the steering angle of the steering wheel 6 when a lane deviation is determined to be absent, and the turning angle is controlled based on an LDP command turning angle for generating a yaw moment in a direction to return the vehicle into the lane while controlling the steering reaction force based on the steering angle without reflecting the LDP command turning angle on the steering reaction force that is applied to the steering wheel 6, when a lane deviation is determined to be present.