Steering Wheel Angle Correlation for Driver Detection

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Solution Overview

Problem

Existing methods for determining whether a vehicle driver is holding the steering wheel are complex and unreliable due to varying driving styles and interference from road disturbances and sensor noise, making it difficult to accurately assess driver input.

Innovation Solution

A method that repeatedly determines the steering wheel angle and calculates error values to find correlations between these measurements, using a correlation function to differentiate between driver input and noise, allowing for reliable detection of whether the driver is holding the steering wheel without requiring a steering torque sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If angular sensors are used to detect driver steering input, then driver steering behavior can be monitored, but road disturbances and sensor noise mask driver input making detection unreliable

Engineering Contradiction:

Improvedriver input detection accuracyVSAvoidroad disturbance and sensor noise interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of road disturbances and sensor noise into a beneficial detection mechanism by analyzing the correlation properties of angular sensor signals. When a driver holds the steering wheel, their hand introduces specific correlation patterns into the angular measurements that differ from random noise. By computing autocorrelation of the angular sensor data and comparing it against threshold values, the system distinguishes genuine driver input from road-induced disturbances, thereby converting noise interference into a reliable detection criterion

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces autocorrelation analysis as an intermediary processing step between raw angular sensor measurements and driver detection. This mathematical operation serves as a mediator that filters out random noise while preserving and amplifying the characteristic correlation patterns introduced by driver hand contact. The autocorrelation function acts as a signal processing intermediary that separates genuine driver input from road disturbances before final detection decision

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If resonant frequency analysis is used to determine driver presence, then detection can be achieved, but the method requires complex steering torque sensors and frequency analysis

Engineering Contradiction:

Improvedriver detection reliabilityVSAvoidsteering torque sensor and frequency analysis system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential detection functionality from complex resonant frequency analysis by isolating only the angular sensor measurements needed for correlation-based detection. Instead of requiring full steering torque sensors and comprehensive frequency domain analysis, the method extracts and utilizes only the angular position data from simpler sensors, applying autocorrelation processing to achieve reliable driver detection with reduced hardware complexity

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical measurement approach (steering torque sensors requiring physical torque measurement) with a signal processing substitution (autocorrelation analysis of angular position data). This substitution eliminates the need for complex mechanical torque sensing hardware while achieving equivalent or superior detection reliability through mathematical analysis of existing angular sensor signals

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If steering torque sensors are used to detect driver input, then accurate driver presence can be determined, but the system becomes more expensive and complex

Engineering Contradiction:

Improvedriver presence detection accuracyVSAvoidsteering torque sensor system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a functional copy of torque sensor capabilities using only angular position data. By analyzing the correlation patterns in angular measurements, the system replicates the driver detection functionality that would otherwise require expensive torque sensors. This virtual copying approach achieves equivalent measurement precision through software-based correlation analysis instead of hardware-based torque measurement

Inventive Principle:

Principle #26Copying

Data Source

PatentUS11267479B2Method and system for determining whether the driver of a vehicle is holding the steering wheel

Publication Date: 2022.03.08 SCANIA CV AB

AI summary

A method for determining whether the driver of a vehicle is holding the steering wheel includes steps of repeatedly determining (S1) the steering wheel angle, repeatedly determining (S2) an error value based on a current determined steering wheel angle value and a previously determined steering wheel angle value; comparing (S3) a determined current error value with previously determined error values to determine a correlation between the error values; determining (S4a) that the driver is holding the steering wheel if the correlation between the error values is above a threshold value or if the driver is not holding the steering wheel if the correlation between the error values is below a threshold value. Also, a system for determining whether the driver of a vehicle is holding the steering wheel by performing the method. Also a computer program and a computer program product for practicing the method.