Steering Wheel Grip Intensity Estimation Beyond Sensor Zones

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Solution Overview

Problem

Existing vehicle systems that estimate grip intensity using pressure sensors on the steering wheel are costly, complex, and unreliable, especially during atypical driving scenarios due to limited dimensionality from modeling.

Innovation Solution

A detection system that computes grip intensity using image data of an operator's hand grasp, relying on inexpensive pressure sensors in limited areas for calibration, and utilizing a learning model trained offline with test images to estimate grip intensity accurately outside sensor areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pressure sensors are installed throughout the steering wheel to improve grip intensity detection accuracy, then measurement precision is improved, but manufacturing cost and device complexity increase

Engineering Contradiction:
Improvegrip intensity detection accuracyVSAvoidsensor installation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The steering wheel is divided into two functional zones: set areas with pressure sensors for calibration and outside set areas without sensors for operational use. This segmentation allows the system to achieve accurate grip intensity measurement through a hybrid approach using both sensor data and image processing, reducing overall sensor requirements while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The learning model is trained offline using test images and sensor data from set areas before actual operation. This preliminary training phase allows the system to learn the relationship between image features and grip intensity, enabling accurate predictions during actual driving without requiring sensors throughout the entire steering wheel.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If pressure sensors are installed throughout the steering wheel to improve grip intensity detection accuracy, then measurement precision is improved, but manufacturing cost increases

Engineering Contradiction:
Improvegrip intensity detection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The steering wheel is divided into two functional zones: set areas with pressure sensors for calibration and outside set areas without sensors for operational use. This segmentation allows the system to achieve accurate grip intensity measurement through a hybrid approach using both sensor data and image processing, reducing overall sensor requirements while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses image data as a virtual copy or representation of the physical grip state. By training a learning model to map image features to grip intensity values, the system creates a computational model that replicates the measurement function, reducing dependence on extensive physical sensor coverage.

Inventive Principle:
Principle #26Copying

3Reliability

If pressure sensors are used to estimate grip intensity, then grip intensity can be detected, but the system produces unreliable estimates during atypical driving scenarios due to limited dimensionality

Engineering Contradiction:
Improvegrip intensity estimation reliabilityVSAvoidapplicability to atypical driving scenarios
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system transitions from relying solely on one-dimensional pressure sensor data to using multi-dimensional image data including hand position, grip posture, and contact area information. This dimensional enrichment allows the learning model to capture diverse gripping patterns and maintain reliability across various driving scenarios, including atypical ones.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The system uses grip measurements from pressure sensors in set areas to provide feedback for calibrating and validating the learning model. This feedback mechanism ensures the model's predictions remain accurate and reliable by continuously comparing model outputs with actual sensor measurements during calibration phases.

Inventive Principle:
Principle #23Feedback

4Reliability

If pressure sensors are installed on the steering wheel to detect grip intensity, then grip information can be obtained, but the system increases bulk and reduces available space

Engineering Contradiction:
Improvegrip intensity detection capabilityVSAvoidsteering wheel bulk
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The steering wheel is divided into two functional zones: set areas with pressure sensors for calibration and outside set areas without sensors for operational use. This segmentation allows the system to achieve accurate grip intensity measurement through a hybrid approach using both sensor data and image processing, reducing overall sensor requirements while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system extracts the essential measurement function from physical sensors throughout the steering wheel and concentrates it into localized sensor arrays in set areas combined with external imaging. This extraction allows the bulk of the steering wheel to remain free of sensors while preserving detection capability through the hybrid measurement approach.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS12272160B2Systems and methods for estimating grip intensity on a steering wheel
Publication Date: 2025.04.08 WOVEN BY TOYOTA INC
  • US12272160B2 patent drawing
  • US12272160B2 patent drawing
  • US12272160B2 patent drawing

AI summary

Systems, methods, and other embodiments described herein relate to implementing and calibrating a learning model for inferring operator intent by estimating grip intensity. In one embodiment, a method includes estimating, using a learning model during a driving scenario, first grip intensity on a steering device for a vehicle according to initial image data depicting a hand of an operator gripping outside the set areas that have pressure sensors. The method also includes calibrating the learning model for the operator and the steering device using grip measurements and additional image data acquired from gripping inside the set areas. The method also includes computing, using the learning model during the driving scenario, second grip intensity outside the set areas on the steering device according to hand images acquired about the operator. The method also includes adapting a vehicle parameter of the vehicle according to the second grip intensity.