Drowsiness determination apparatus, program, and method

• US 7,948,387 B2
• Filed: 02/29/2008
• Issued: 05/24/2011
• Est. Priority Date: 03/08/2007
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ishida, Kenji, Uchiyama, Kahori
• Primary Examiner(s): Zimmerman; Brian A
• Assistant Examiner(s): SAMSON, SARA B
• Application Number:
  US12/073,075
• Publication Number:
  US 20080218359A1
• Time in Patent Office: 1,180 Days
• Field of Search: 340/575, 340/573.1, 340/540, 340/500
• US Class Current: 340/575
• CPC Class Codes: G06V 40/171 Local features and components; Facial parts eye characteristics G06V40/18; Occluding parts, e.g. glasses; Geometrical relationships
• CPC Class Codes: G08B 21/06 indicating a condition of sleep, e.g. anti-dozing alarms

Abstract

An apparatus for accurately determining a drowsiness level is provided. A doze prevention system includes a photographic apparatus, a drowsiness determination apparatus, and other apparatuses for doze prevention such as an alarm apparatus, a neck air conditioning apparatus, a seat belt vibrating apparatus, and a brake control apparatus. The photographic apparatus captures a facial image of a driver of a vehicle. The drowsiness determination apparatus determines a drowsiness level based on the facial image. The drowsiness determination apparatus uses a facial image captured by the photographic apparatus, detects a sign of drowsiness or a sign of struggle, and determines the drowsiness level based on the detection results.

Claims

1. A drowsiness determination apparatus comprising:

a decreased wakefulness detection means for detecting a sign of decreased wakefulness due to drowsiness based on an eye opening degree;

a struggle detection means for detecting a sign of struggle against drowsiness based on a distance between an eyebrow and the eye just below the eyebrow; and

a drowsiness determination means for determining a drowsiness level based on the sign of decreased wakefulness and the sign of struggle, wherein

the drowsiness determination means determines no drowsiness when the sign of decreased wakefulness is not detected, determines possession of drowsiness when the sign of decreased wakefulness is detected, and determines a drowsiness level according to presence or absence of the sign of struggle in a state where the possession of drowsiness is determined;

the drowsiness determination means determines;

a condition A where the eye opening degree is less than or equal to a first threshold value;

a condition B where the eye opening degree is less than or equal to a second threshold value smaller than the first threshold value; and

a condition C where the distance between an eyebrow and the eye just below the eyebrow is greater than a specified threshold value; and

wherein

the drowsiness determination means determines a drowsiness level as strong drowsiness when the condition B is satisfied; and

wherein

the drowsiness determination means determines the drowsiness level as medium drowsiness lower than the strong drowsiness when the condition A and the condition C are satisfied and the condition B is not satisfied; and

wherein

the drowsiness determination means determines the drowsiness level as weak drowsiness lower than the medium drowsiness when the condition A is satisfied and the condition B and the condition C are not satisfied; and

wherein

the drowsiness determination means determines the drowsiness level as no drowsiness when the condition A and the condition B are not satisfied.

2. The drowsiness determination apparatus of claim 1, wherein

the eye opening degree is based on a distance between an upper eyelid and a lower eyelid,

the distance between an eyebrow and the eye just below the eyebrow is based on a distance between the center of outer corner and inner corner of the eye and an upper end of the eyebrow.

3. The drowsiness determination apparatus of claim 1, wherein

the drowsiness determination means determines the drowsiness level as a level higher than the strong drowsiness when the eye opening degree is less than or equal to a third threshold value smaller than the second threshold value, regardless of the other conditions.

4. The drowsiness determination apparatus of claim 1, further comprising

a position information detection means for detecting position information indicative of positions of an eye and an eyebrow on a facial image shown by an image data, wherein

the decreased wakefulness detection means specifies an eye opening degree based on the position information, and wherein

the struggle detection means specifies the distance between an eyebrow and the eye just below the eyebrow based on the position information.

5. The drowsiness determination apparatus of claim 4, wherein

the drowsiness determination apparatus is mounted on a vehicle;

and wherein

the position information detection means detects the position information indicative of positions of an eye and an eyebrow on a facial image shown by an image data captured by a capturing means mounted on the vehicle.

6. An article of manufacture comprising a computer readable medium and instructions carried on the medium, the instructions forming a computer program that when read and executed cause a computer to perform processes to thereby functioning as the decreased wakefulness detection means, the struggle detection means, and the drowsiness determination means described in claim 1.