Steering Wheel Hold Detection via Resonant Frequency Shift
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Solution Overview
Problem
Current vehicle systems lack a reliable and quick method to determine whether a driver is holding the steering wheel, especially in autonomous or semi-autonomous driving modes, which is crucial for safety and vehicle control.
Innovation Solution
A system that monitors steering torque and resonant frequency of oscillation, comparing the measured resonant frequency to a known natural frequency of the steering system to determine if the driver is holding the wheel, with a measured steering torque above a threshold indicating driver engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional driver presence detection methods are used, then the system structure remains simple, but the detection reliability and speed are insufficient for autonomous driving modes
Solution Approach 1:
The system uses the steering system's own components (torque sensor, angle sensor, resonant frequency characteristics) to detect driver engagement, eliminating the need for separate detection hardware. The steering system serves dual purposes: providing steering assistance and detecting driver presence through monitoring its own operational parameters
Solution Approach 2:
The system detects driver engagement by monitoring changes in physical parameters of the steering system, specifically resonant frequency shifts and steering torque variations. When a driver holds the steering wheel, the system's resonant frequency changes due to the driver's mass and grip, providing a reliable detection mechanism
2Measurement precision
If additional detection hardware is added to improve detection accuracy, then detection precision improves, but device complexity and cost increase
Solution Approach 1:
The steering system's existing sensors (torque sensor, angle sensor) are used for multiple purposes: controlling steering assistance and detecting driver engagement. This multi-functional approach eliminates the need for dedicated detection hardware while maintaining high detection precision
Solution Approach 2:
The steering system monitors its own characteristics (resonant frequency, torque) to detect driver presence, using its inherent properties for self-diagnosis and driver engagement detection without external hardware
3Loss of time
If the system requires quick detection of driver engagement, then safety response time improves, but the complexity of real-time monitoring increases
Solution Approach 1:
The system continuously monitors steering torque and angle parameters during normal operation, maintaining constant awareness of driver engagement status without requiring separate detection phases or additional processing cycles
Solution Approach 2:
The system uses feedback from the steering sensors to continuously update the driver engagement status. The control unit receives real-time torque and angle data, analyzes resonant frequency changes, and immediately determines driver presence, enabling rapid response
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
Enables immediate and reliable detection of driver engagement, supporting safe transitions between manual and autonomous driving modes, and reducing driver vigilance concerns by quickly identifying hands-on or hands-off situations without requiring additional hardware.
Implementation Method 1
determines a resonant frequency of oscillation of the steering system from the measured data, and compares the resonant frequency to a known natural frequency of the steering system
Data Source
AI summary
A system and method for determining whether a vehicle driver is holding a steering wheel of the vehicle. The vehicle will include an electric power steering (EPS) system and may include an active front steering (AFS) system. The vehicle may further include autonomous or semi-autonomous driving features or safety features, such as Lane Centering Control (LCC) or Lane Keeping Assist (LKA). The system monitors steering torque and steering angle signals, determines a resonant frequency of oscillation of the steering system from the measured data, and compares the resonant frequency to a known natural frequency of the steering system. If the resonant frequency is lower than the known natural frequency, then the system knows that the vehicle driver is holding the steering wheel. A measured steering torque greater than a threshold value is also taken as an immediate indication of the driver holding the steering wheel.