Awake State Estimation Device Curved Path Correction
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Solution Overview
Problem
Existing awake state estimation devices for drivers fail to accurately estimate the awake state while driving on curved paths due to variations in driving skill and path characteristics, leading to insufficient restraint of the effect of curved path travel on estimation results.
Innovation Solution
An awake state estimation device that acquires traveling information, including steering angle, and uses correction values and expressions to calculate a corrective steering angle, which is then standardized to reduce the influence of curved path travel on estimation, allowing for accurate awake state determination based on the corrected angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the awake state is determined on the basis of peak frequency of steering spectrum when traveling on a curved path, then the estimation can be simplified, but the estimation accuracy deteriorates due to curvature effects
Solution Approach 1:
The patent extracts the harmful effect of path curvature from the steering spectrum analysis by introducing a separate path curvature detection mechanism. The curvature information is then removed or compensated for in the steering angle signal before awake state estimation, allowing the use of simplified peak frequency analysis while maintaining accuracy.
Solution Approach 2:
The patent applies different processing methods to different components of the steering signal. The overall steering spectrum is analyzed for peak frequency (simplified approach), while simultaneously, path curvature is detected and used to correct specific frequency components, achieving both simplicity and accuracy in different parts of the estimation process.
2Measurement precision
If the integrated value of spectrum is used for awake state estimation on curved paths, then the curvature effect is reduced, but the estimation response becomes slower
Solution Approach 1:
The patent segments the steering spectrum into multiple frequency bands and processes each band separately. By dividing the spectrum analysis into discrete frequency ranges, the system can quickly identify peak frequencies in each segment while maintaining the accuracy benefits of comprehensive spectral analysis, thus improving response speed without sacrificing precision.
3Device complexity
If corrective steering angle is calculated without correction values, then the calculation process is simpler, but the estimation accuracy deteriorates due to path type variations
Solution Approach 1:
The patent performs preliminary detection and classification of path types (straight, curved, turning) before calculating the corrective steering angle. This preliminary action allows the system to select appropriate correction values or processing methods in advance, simplifying the main calculation process while ensuring accuracy through pre-prepared correction data specific to each path type.
Data Source
AI summary
An awake state estimation portion calculates an average steering angle, an average steering angular speed and a corrective steering angle on the basis of the steering angle acquired from a steering angle detection portion. The awake state estimation portion acquires the traveling speed of the vehicle from a vehicle speed detection portion. The awake state estimation portion corrects the calculated corrective steering angle by a correction value commensurate with the type of the traveling path on which the vehicle is traveling, and estimates the degree of the awake state of the driver on the basis of the post-correction corrective steering angle. Besides, the awake state estimation portion specifically determines the correction value commensurate with the type of the traveling path on which the vehicle is traveling, on the basis of at least one of the steering angle, the average steering angular speed and the traveling speed.