Driver Monitoring by Surprise Expression Frequency

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Solution Overview

Problem

Current driver monitoring technologies are inadequate in precisely judging cognitive functions and enhancing safety for drivers with declining cognitive abilities.

Innovation Solution

A driver monitoring device that uses a processor to analyze facial expressions captured by an imaging device, calculates the frequency of surprise expressions, and performs safety-enhancing processing when the frequency exceeds a threshold, including issuing warnings and activating driver assistance systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If driver monitoring uses traditional methods (speech data, operation frequency), then the system complexity is low, but the measurement precision of cognitive function assessment is insufficient

Engineering Contradiction:
Improvecognitive function assessment precisionVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical/operational monitoring methods with optical imaging technology. Specifically, it uses an imaging device to capture facial expressions and replaces complex operational data analysis with image processing algorithms that detect surprise expressions, thereby improving measurement precision while managing system complexity through substitution of the monitoring approach.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the monitoring parameter from operational metrics (speech frequency, operation count) to physiological/expressive metrics (facial expression frequency). By focusing on the frequency of surprise expressions as a key parameter, the system achieves more precise cognitive function assessment through a different measurable attribute that directly reflects driver alertness and cognitive state.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the monitoring system uses multiple judgment items and complex analysis, then the cognitive function assessment becomes more comprehensive, but the ease of operation and response time deteriorate

Engineering Contradiction:
Improvecognitive function judgment reliabilityVSAvoidsystem operation simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent extracts the most critical indicator from complex cognitive function assessment - the surprise expression frequency. Instead of analyzing multiple cognitive parameters simultaneously, the system isolates and monitors specifically the frequency of surprise expressions, which serves as a reliable proxy for cognitive function while simplifying the operational complexity and enabling faster response.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary classification of facial expressions to identify surprise expressions before calculating their frequency. This preliminary action of categorizing expressions ensures reliable cognitive function judgment while maintaining operational simplicity by automating the classification process and focusing subsequent analysis only on relevant surprise expression data.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the threshold value is set low for early detection, then the safety enhancement timing is improved, but the false alarm rate increases

Engineering Contradiction:
Improvesafety detection accuracyVSAvoidfalse alarm rate
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the threshold for surprise expression frequency is dynamically adjusted based on learned normal values for each driver. The system continuously monitors and compares current surprise expression frequency against the driver's baseline, providing feedback that enables accurate early detection of cognitive decline while minimizing false alarms by accounting for individual driver characteristics and normal variations.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS20240286613A1Driver monitoring device, driver monitoring method, and non-transitory recording medium
Publication Date: 2024.08.29 TOYOTA JIDOSHA KK
  • US20240286613A1 patent drawing
  • US20240286613A1 patent drawing
  • US20240286613A1 patent drawing

AI summary

The driver monitoring device includes an expression judgment part configured to judge an expression of a driver of a vehicle from an image generated by an imaging device capturing a face of the driver; and a processing part configured to calculate a frequency by which it is judged the expression of the driver is an expression of surprise and perform a predetermined processing for enhancing a safety of the driver when the frequency is greater than or equal to a threshold value.