Vehicle Yaw Stability Control via Road Trajectory Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional yaw stability control systems rely heavily on driver input and are ineffective in situations where drivers, especially inexperienced or panicked ones, fail to guide the vehicle safely, leading to loss of control and accidents.
Innovation Solution
A vehicle yaw stability control method that measures yaw rate, sets a reference yaw rate based on road shape information, and triggers stabilizing braking interventions when the driver's input is deemed unreliable, using a replacement reference yaw rate calculated from road shape and longitudinal velocity, or through a lane keeping controller algorithm, to maintain vehicle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional yaw stability control systems rely on driver steering input to determine reference trajectory, then the system is simple to operate and respects driver intent, but the system becomes ineffective when drivers panic or lack skill, leading to loss of control
Solution Approach 1:
The system dynamically switches between two control modes: driver-intent-based control under normal conditions and road-trajectory-based control when driver input is deemed unreliable. This dynamic adaptation allows the system to maintain effectiveness across different driving scenarios while preserving driver autonomy during normal operation.
Solution Approach 2:
A driver monitoring system acts as an intermediary that evaluates driver reliability and triggers mode switching. This intermediary layer enables the system to assess driver state and appropriately select between driver-based and system-based trajectory determination without direct driver intervention.
2Device complexity
If the system uses driver steering angle through a simplified vehicle model to compute reference trajectory, then the control logic is simple and responsive to driver intent, but it fails to account for road curvature and adhesion limits, causing vehicle motion to reach adhesion limits
Solution Approach 1:
The system dynamically selects between a simplified vehicle model approach (for normal conditions) and a road-shape-based reference trajectory approach (for challenging conditions). This dynamic selection allows the system to maintain simplicity during routine driving while achieving accurate trajectory tracking and adhesion management during critical situations.
Solution Approach 2:
The system changes the reference trajectory generation parameters based on driving conditions. Under normal conditions, it uses driver steering angle and simplified vehicle dynamics parameters. Under challenging conditions, it switches to using road shape information and adhesion-aware parameters to generate the reference trajectory.
3Speed
If stabilizing braking intervention is triggered based on difference yaw rate comparison with threshold values, then the response is fast and automatic, but it may trigger unnecessarily or fail to address the root cause when driver input is the problem
Solution Approach 1:
The system performs preliminary evaluation of driver reliability before triggering stabilizing braking intervention. By assessing driver state and input reliability in advance, the system ensures that braking intervention is only activated when truly necessary and appropriate, reducing unnecessary interventions while maintaining fast response when needed.
Solution Approach 2:
The system uses feedback from the driver monitoring system to continuously assess whether driver input is reliable. This feedback mechanism allows the system to adjust its control strategy in real-time, triggering stabilizing braking only when driver input is deemed unreliable and the vehicle is in an unsafe state, thereby improving intervention accuracy.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments herein relate to a vehicle yaw stability control method as well as a vehicle yaw stability control apparatus (1). The yaw rate ψ̇ of the vehicle is measured. A first reference yaw rate ψ̇ref is set. A difference yaw rate Δψ̇ is set. Stabilizing braking intervention is triggered when a value of the difference yaw rate Δψ̇ exceeds limits defined by difference yaw rate threshold values Δψ̇min , Δψ̇max. Information regarding the shape of the road ahead of the vehicle is acquired. The reliability of the driver steering input δ is evaluated upon stabilizing braking intervention being triggered. In case the driver steering input δ is deemed unreliable a replacement reference yaw rate ψ˙refroad is set based on the acquired road shape and a replacement difference yaw rate Δψ̇road is set whereupon stabilizing braking intervention is performed based on the replacement difference yaw rate Δψ̇road.