Vehicle Understeer Detection via Yaw Rate Derivative
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting loss of grip in vehicles are complex, costly, and affect responsiveness and reliability due to the need for additional sensors and complex calculations.
Innovation Solution
A method using the partial derivative of the yaw rate with respect to the steering wheel angle as an indicator to detect understeer or oversteer situations, allowing for early and accurate diagnosis of grip conditions, which can be implemented in a simple and cost-effective manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors are added to collect dynamic information, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The invention uses data already collected by existing vehicle sensors (steering angle sensor, yaw rate sensor) to detect loss of grip situations. The system makes existing resources serve dual purposes - their original functions plus the additional function of detecting adhesion loss, eliminating the need for dedicated sensors.
Solution Approach 2:
The monitoring system is designed to perform multiple functions using existing sensors. The steering angle sensor and yaw rate sensor serve both their primary navigation/control functions and the additional function of detecting loss of grip situations through the derivative calculation method.
2Measurement precision
If complex calculations are performed for monitoring, then measurement precision is improved, but productivity decreases
Solution Approach 1:
The invention extracts only the essential mathematical relationship needed for detection - the derivative of yaw rate with respect to steering angle. By focusing on this single key parameter rather than comprehensive complex models, the system achieves accurate detection with minimal computational burden.
Solution Approach 2:
The invention transforms the monitoring approach by changing from monitoring multiple complex parameters to monitoring a single derived parameter (the derivative). This parameter transformation simplifies the calculation while maintaining detection accuracy, as the derivative directly indicates loss of grip conditions.
3Reliability
If more sensors are added, then reliability is improved, but device complexity increases
Solution Approach 1:
The existing sensor system serves dual purposes - its original functions plus reliable detection of loss of grip situations. The redundancy and reliability are achieved through clever use of existing data rather than adding more sensors, maintaining reliability while avoiding increased complexity.
4Measurement precision
If complex monitoring processes are implemented, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The invention extracts only the critical computational element - the derivative calculation - from complex monitoring processes. This extraction enables fast, real-time detection without the computational overhead of complex models, achieving both precision and speed.
Solution Approach 2:
The system skips complex intermediate calculation steps by directly computing the derivative of yaw rate with respect to steering angle. This direct approach rushes through the essential calculation needed for detection without unnecessary computational delays.
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to a method for detecting a situation in which a vehicle provided with a steering system operated by a steering wheel is losing grip, said method being characterized in that it comprises a step (a) of evaluating a first loss-of-grip indicator (P1) during which step the partial derivative (P1 = ∂ψ /∂α) with respect to a variable (α) indicative of the angular position of the steering wheel, of a rolling parameter indicative of the rate of yaw (ψ) of the vehicle is calculated by way of first loss-of-grip indicator (P1).