Driver State Detection Protocol for Cognitive Workload Data

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Solution Overview

Problem

Existing methods for collecting data on human psychophysiological states during driving experiments are prone to biases and inconsistencies, making it difficult to derive reliable results for developing advanced driver assistance systems (ADAS).

Innovation Solution

A structured protocol involving multiple driving stages in a car simulator, including monotonous and complex scenarios, with simultaneous cognitive tests and data collection using physiological and behavioral metrics such as heart rate, EEG, eye movement, and steer wheel activity, along with self-reported data, to consistently gather and analyze data on driver states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If data is collected during driving experiments using conventional methods, then data can be gathered, but biases are introduced affecting reliability

Engineering Contradiction:
Improvedata reliabilityVSAvoidexperiment structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The driving experiment is divided into multiple distinct stages (baseline driving, cognitive test with driving, dual-task driving) with specific durations and conditions. Each stage serves a particular purpose in collecting different types of psychophysiological data, allowing systematic analysis while maintaining experimental control and reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A baseline driving stage is conducted before cognitive tests to establish reference psychophysiological states. This preliminary data collection allows comparison with subsequent stages, enabling detection of changes in driver state while controlling for individual variability and reducing bias

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If multiple physiological parameters are collected simultaneously, then comprehensive psychophysiological data is obtained, but data processing and analysis becomes difficult

Engineering Contradiction:
Improvevolume of psychophysiological dataVSAvoiddata analysis difficulty
Core Design Contradiction:
Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

Different physiological parameters (EEG, ECG, eye tracking, respiration) are collected during segmented driving stages rather than continuously throughout. This temporal segmentation reduces the total volume of data requiring analysis while preserving critical information about driver state changes under different cognitive loads

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate processing steps including data synchronization across multiple sensors, artifact removal protocols, and feature extraction methods that transform raw physiological signals into meaningful metrics. These intermediary processes simplify subsequent analysis while maintaining data comprehensiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If cognitive tests are performed simultaneously with driving, then cognitive workload is measured, but driving performance may be affected

Engineering Contradiction:
Improvecognitive workload measurement accuracyVSAvoidimpact on driving performance
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The experimental protocol dynamically adjusts the complexity and duration of cognitive tests based on driving conditions and participant performance. Cognitive load is modulated to remain within safe limits that do not compromise driving safety, while still providing sufficient challenge to measure cognitive workload accurately

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses simulated driving environments rather than real driving, creating a safe copy of actual driving conditions. This allows simultaneous cognitive testing without real-world safety risks, while the simulation maintains ecological validity for measuring cognitive workload

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4437961A1Driver psychophysiological state detection
Publication Date: 2024.10.02 HARMAN INT IND INC
  • EP4437961A1 patent drawingFigure 1A~2B
  • EP4437961A1 patent drawingFigure 3A~3B
  • EP4437961A1 patent drawingFigure 4

AI summary

It is herein disclosed a method of collecting data for determining a psychophysiological state of a human driver, comprising collecting data throughout a driving session in a car simulator, wherein the driving session comprises a plurality of driving stages, wherein the plurality of driving stages comprise, at least: a first stage of driving by a driver in a first scenario; a second stage of driving by the driver in a first scenario, wherein a first cognitive test is performed by the driver simultaneously with the driving; a third stage of driving by the driver in a second scenario; a fourth stage of driving by the driver in the second scenario, wherein a second cognitive test is performed by the driver simultaneously with the driving; wherein said collecting data comprises: collecting, by a plurality of detection means, physiological data on the driver throughout the driving session; wherein the physiological data collected comprises at least one of heart rate data, electroencephalogram (EEG) data, eye movement data, and respiration data; and collecting driver behaviour data, comprising: recording steer wheel activity of the driver; and recording the driver's reaction to the cognitive tests; where each of the first and second cognitive tests is an N-back test; and wherein the first scenario is a relatively monotonous driving scenario comprising simulated highway driving and the second scenario is a relatively complex scenario comprising simulated urban road driving.