JP4793269B2 - Sleepiness detection device - Google Patents

Description

  The present invention relates to a drowsiness detection device that detects drowsiness of a driver of a vehicle.

  Conventionally, photographing means for photographing a driver's face, an image processing circuit for detecting driver's sleepiness from an image photographed by the photographing means, and warning means for issuing a warning when sleepiness is detected by the image processing circuit; There is known a drowsiness detection device including

In this type of drowsiness detection device, the opening degree of the driver's eyes (that is, the distance between the upper eyelid and the lower eyelid) and the closing time during blinking are calculated from the captured image, and these values are set in advance. Based on the evaluation time of blinking set from the closing time of blinking specific to the driver at the time of awakening or detecting the drowsiness by comparing with Has been proposed to detect long blinks (hereinafter referred to as long blinks) and detect drowsiness from the ratio of the total number of blinks and long blinks within a predetermined time (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 6-266981 Japanese Patent Laid-Open No. 10-272960

  By the way, when driving the vehicle, the driver needs to look at the meter provided in the vehicle in addition to the gazing point set in front of the vehicle (that is, the position where the driver should watch). It is necessary to turn the line of sight downward than the line of sight to the viewpoint (hereinafter, turning the line of sight downward is referred to as a downward view).

  However, in the conventional drowsiness detection device, the opening degree of the eye when looking downward is very similar to the opening degree of the eye when drowsiness occurs. The possibility of misrecognizing that sleepiness occurred was high.

Further, in the conventional drowsiness detection device, since the opening degree of the eye when viewed downward in the captured image is small, it is determined that the image processing circuit is actually closing the eye even if the eye is open. As a result, the close time at the time of blinking when looking downward and the closing time of the blink when sleepiness occurs are approximately the same time, and there is a possibility that the downward view may be mistaken for the occurrence of sleepiness. In order to solve this problem, research on a method for detecting downward vision based on the difference between the shape of the driver's eyelid when looking down and the shape of the eyelid when sleepiness occurs It is being advanced. In this method, it is necessary to accurately recognize the shape of the driver's eyelid.

  However, since the conventional drowsiness detection device captures an image for recognizing the opening degree of the eyes, it is difficult to accurately recognize the shape of the driver's eyelid from the image captured by the imaging unit. Met.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a drowsiness detection device that can accurately recognize the shape of a driver's eyelid and accurately detect that the driver is looking downward.

  The drowsiness detection device of the present invention made to achieve the above object is based on the photographed image including the face of the driver of the vehicle photographed by the photographing means, and the contour shape extracting means extracts the contour shape of the driver's lower eyelid. Then, the downward vision detection means detects the downward vision in which the driver directs his gaze below the gaze to the gazing point preset in front of the vehicle based on the contour shape extracted by the contour shape extraction means, Based on the driver's arousal level estimated from the photographed image taken by the imaging unit, the drowsiness detection unit cancels the reduction in the arousal level due to the downward vision when the downward vision detection unit detects the downward vision. The degree of wakefulness is corrected and the driver's drowsiness is detected based on the degree of wakefulness, and the photographing means is formed by the boundary between the driver's lower eyelid and the eyeball, and is in the driver's eyeball. The first that can shoot reflected shadows Those disposed location position.

  In the drowsiness detection device of the present invention, the photographing means arranged at the first arrangement position is formed by the boundary between the driver's lower eyelid and the eyeball, and photographs the shadow reflected in the driver's eyeball. In the photographed image, the brightness difference at the boundary between the driver's lower eyelid and the eyeball, that is, the contour shape of the driver's lower eyelid becomes clear.

  Therefore, according to the drowsiness detection device of the present invention, the contour shape of the driver's lower eyelid can be accurately extracted from the captured image. As a result, according to the drowsiness detection device of the present invention, it is possible to improve the detection accuracy that the driver is looking downward, and thus the detection accuracy of the driver's drowsiness can be improved.

  In addition, the first arrangement position in the drowsiness detection device of the present invention includes a driving gaze axis that is a direction of the driver's gaze to the gazing point and a driver's gaze to the gazing point, as described in claim 2. It is the area in the vehicle that is sandwiched between the driver's eyes when facing and the lowest position of the lower eyelid on the lower shaft that is a straight line connecting the cross section including the full length direction and the height direction of the vehicle It is desirable that the position is within the specified area.

  According to the drowsiness detection device in which the photographing means is arranged in such a prescribed region, it is possible to increase the possibility that a photographed image is captured so that the contour shape of the driver's lower eyelid becomes clearer.

  In particular, if the first arrangement position in the drowsiness detection device of the present invention is inside the instrument panel or meter of the vehicle as described in claim 3, a sharply-captured photographed image can be taken. The sex can be increased.

  In addition, as described in claim 4, the drowsiness detection device of the present invention includes an irradiation unit that irradiates the driver's face with irradiation light, and the irradiation unit irradiates the irradiation light, thereby driving. It is desirable that the shadow formed by the boundary between the person's lower eyelid and the eyeball is arranged at the second arrangement position such that the shadow is projected into the eyeball.

  According to the drowsiness detection device of the present invention that captures a shadow projected in the eyeball as a captured image, the brightness difference at the boundary between the driver's lower eyelid and the eyeball, that is, the contour shape of the driver's lower eyelid is clearer. The photographed image can be photographed so that

  Therefore, according to the drowsiness detection device of the present invention, it is possible to further improve the accuracy of detecting that the driver is looking downward, and further improve the accuracy of detecting the drowsiness of the driver.

And as for the 2nd arrangement position in the drowsiness detection apparatus of this invention, as for Claim 5, it is desirable that it is below the 1st arrangement position where an imaging | photography means is arrange | positioned.
According to such a drowsiness detection device of the present invention, by irradiating irradiation light from the irradiation means, a shadow at the boundary between the lower eyelid and the eyeball projected into the driver's eyeball, that is, a lower part of the driver. The face of the driver in a state where the contour shape of the eyelid becomes clearer can be photographed as a photographed image.

  Therefore, according to the drowsiness detection device of the present invention, it is possible to further improve the accuracy of detecting that the driver is looking downward, and further improve the accuracy of detecting the drowsiness of the driver.

  The drowsiness detection device according to the present invention, as described in claim 6, extracts contour shapes based on the light reflected from the irradiation means toward the driver's face on the driver's face. The means extracts the contour shape of the driver's lower eyelid, and the downward vision detection means is below the line of sight to the gazing point preset in front of the vehicle based on the contour shape extracted by the contour shape extraction means. When the driver detects a downward view in which the line of sight is directed and the drowsiness detection means detects the downward view by the downward view detection means based on the driver's arousal level estimated from the photographed image taken by the photographing means, By correcting the wakefulness so that the decrease in the wakefulness due to vision is offset, the driver's sleepiness is detected based on the wakefulness, and the irradiation means irradiates the irradiation light, Formed at the boundary between the driver's lower eyelid and eyeball There may be one which is disposed in the second position, as projected into the eye.

In such a drowsiness detection device, a method of recognizing the contour shape of the lower eyelid by irradiating laser light or the like can be considered.
Further, the second arrangement position in the drowsiness detection device of the present invention is the lowest position of the driver's eyes and the lower eyelid when the driver is gazing at the gazing point as described in claim 7. Is preferably below the lower shaft, which is a straight line connecting the cross section including the full length direction and the height direction of the vehicle.

  According to such a drowsiness detection device in which the irradiation means is arranged at the second arrangement position, it is possible to increase the possibility of photographing a photographed image that makes the contour shape of the lower eyelid of the driver clearer.

  In particular, if the second arrangement position in the drowsiness detection device of the present invention is on the extension line of the steering column in the steering wheel provided in the vehicle as in claim 8, a sharply-captured photographed image is taken. The possibility of being made can be increased.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a drowsiness detection device to which the present invention is applied and is mounted on a vehicle. Hereinafter, a vehicle equipped with the drowsiness detection device is referred to as an on-board vehicle.
<Device configuration>
The drowsiness detection device 1 includes a light source 13 that irradiates an irradiation area including a driver's face of an onboard vehicle, and a camera 12 that captures an image including the driver's face irradiated with the irradiation light from the light source 13. The image processing processor 10 detects the driver's sleepiness based on the image captured by the camera 12, and the speaker 11 outputs the sound by the audio signal from the image processing processor 10.

Here, FIG. 5 is an explanatory diagram for explaining a position where the camera 12 and the light source 13 are arranged, and FIG. 6 is an explanatory diagram showing a longitudinal section in a peripheral region of the driver's eyes.
The light source 13 is configured around a light emitting diode that emits light in accordance with a light emission signal from the image processor 10, and irradiates irradiation light at a pre-defined spread angle.

  Further, as shown in FIG. 5, the light source 13 is formed in the driver's eyeball in a state of being seated on the seat of the mounted vehicle (hereinafter referred to as a seated state) at the boundary between the driver's lower eyelid and the eyeball. This is a position to project a shadow to be projected, and is arranged below a lower axis set in advance as an axis extending from the driver's eyes (that is, a position close to the road surface). Specifically, in this embodiment, it is arranged on the extension line of the steering column in the steering wheel, and this position is set as the second arrangement position.

  However, as shown in FIG. 6, the lower axis means that when the seated driver is looking at a gaze point that is set in front of the mounted vehicle in advance, the full length direction and the vehicle height direction of the mounted vehicle. Is a straight line connecting the driver's eye corners and the lowest position of the lower eyelid (that is, the position close to the road surface, hereinafter referred to as the lowest point).

  Next, the camera 12 has a light receiving unit composed of a CCD element, and the light receiving unit receives light through a lens in accordance with an imaging signal from the image processing processor 10 to capture a digital image (hereinafter, the captured digital image is captured). A photographed image).

  Further, as shown in FIG. 5, the camera 12 has a line of sight when a driver in a seated state is turning his / her line of sight toward a point of sight set in front of the mounted vehicle. This is a position sandwiched between the gaze axis indicating the direction and the lower axis, and is disposed at a position where a shadow formed on the boundary between the lower eyelid of the driver and the eyeball can be photographed. Specifically, in this embodiment, it arrange | positions in the position where the speedometer or the rotational speedometer is provided, and let this position be a 1st arrangement position.

However, the gaze axis is an axis that is lower than a horizontal axis (that is, an axis parallel to the road surface) extending in the horizontal direction from the position of the eyes of the driver in the seated state.
The image processor 10 also includes a program for executing various processes, a ROM 10a for storing data, a RAM 10b for temporarily storing data, and a CPU 10c for executing processes according to the program stored in the ROM 10a. I have.

  It should be noted that the ROM 10a is used for extracting a face for simulating a human eye, nose, mouth, and the like as a template necessary for executing various processes on the photographed image and extracting the driver's face from the photographed image. A template, an eye extraction template for simulating a human eye and extracting a driver's eye from a photographed image, and the like are stored.

That is, the image processor 10 is configured to be able to execute sleepiness warning processing for estimating a driver's sleepiness level based on a photographed image captured by the camera 12 and issuing a warning to the driver.
<Drowsiness warning processing>
Next, sleepiness warning processing executed by the CPU 10c of the image processor 10 will be described.

Here, FIG. 2 is an explanatory diagram illustrating a processing procedure of the drowsiness warning process.
This drowsiness warning process is started when the operation of the onboard vehicle is started (in this embodiment, when the engine is started).

  When the drowsiness warning process is started, first, in S110, a light emission signal is output to the light source 13, and an image pickup signal is output to the camera 12, causing the camera 12 to take a photographed image. Acquire the captured image.

  In subsequent S120, based on the captured image acquired from the camera 12, a facial region where the driver's face is captured is extracted. Specifically, in the present embodiment, the face extraction template is pattern-matched from a predetermined specified pixel of a captured image acquired from the camera 12 in a specified direction, and the face extraction template and a predetermined ratio specified in advance. The region of the captured image that matches is extracted as a face region.

  Further, in S130, a peripheral region of the eyes including the driver's upper eyelid and lower eyelid is extracted from the facial region extracted in S120. Specifically, in the present embodiment, the face extraction region is subjected to pattern matching from a predetermined prescribed pixel of the facial region in a prescribed direction, and matches the eye extraction template at a prescribed proportion or more. A part of the area is recognized as the driver's eyes. And the area | region of the magnitude | size prescribed | regulated beforehand so that the area | region may be included is extracted from the area | region recognized as the driver | operator's eyes.

In subsequent S140, the driver's blink is detected based on the peripheral area of the eye extracted in S130.
Specifically, in this embodiment, every time a peripheral region of the eye is extracted in S130, as shown in FIG. 7A, the eyeball and eyelid in the peripheral region of the eye (that is, in the captured image) Based on the difference in brightness, the distance between the upper eyelid (that is, the highest point of the upper eyelid (position closest to the top of the head)) and the lower eyelid (that is, the lowest point of the lower eyelid (position closest to the road surface)) (hereinafter, This distance is set as the eye opening). Then, the calculated opening of the eyes is stored in the RAM 10b together with the elapsed time from the start of operation.

  The relationship between the eye opening and the elapsed time from the start of operation (hereinafter referred to as blink detection relationship) is represented as a graph as shown in FIG. However, in the blink detection relationship in the present embodiment, the eye opening is handled after being replaced with a ratio with the maximum distance within a predetermined time immediately after the start of driving when the driver is awake. Yes.

That is, in S140, the time change of the opening degree of the driver's eyes, that is, the blinking state of the driver is obtained.
In subsequent S150, the driver's sleepiness is estimated based on the time change of the eye opening stored in the RAM 10b in S140, that is, the arousal level representing the driver's arousal state is calculated.

  Specifically, the degree of arousal is calculated according to the blinking time (that is, the time during which the eyes are closed) in which the opening degree of the eyes in one blink is equal to or less than a predetermined ratio. In particular, if the blink time is short, it is assumed that the driver is awake, and the arousal level is calculated so that the value increases.If the blink time is long, the value is assumed that the driver feels sleepy. The arousal level is calculated so as to be lower. Then, depending on the calculated degree of wakefulness, a wakefulness level as a wakefulness state determination index in warning processing described later is set in five stages.

Further, in S160, binarization is performed so that the luminance difference between the eyeball and the eyelid is clear in the peripheral area of the eye extracted in S130 in the photographed image.
In subsequent S170, a downward vision detection process for detecting the direction of the driver's line of sight is executed based on the eye peripheral region binarized in S160.

  After that, in S180, the detection result in the downward vision detection process performed in S170 above indicates that the driver visually recognizes the meter or the like, that is, the downward vision in which the driver is looking downward from the gaze axis. It is determined whether or not. And as a result of determination, when it is determined that the driver's line of sight is a downward view, the process proceeds to S190.

Specifically, in the present embodiment, it is determined whether or not it is a downward view depending on whether or not a downward view flag (or a normal view flag) described later is set.
In S190, the wakefulness calculated in the previous S150 in a state of being lowered due to the driver's downward view is corrected so that the reduced amount is offset (hereinafter, the corrected wakefulness is corrected). Then, the process proceeds to S200. Specifically, in the present embodiment, the wakefulness level calculated in S150 is increased by two stages (that is, corrected so that the wakefulness level is increased).

  In addition, as a result of the determination in S180, the driver's line of sight is other than the downward view (for example, when the line of sight is directed toward the gazing point or when the mirror in the mounted vehicle is viewed). If it is determined, the process proceeds to S200 without correcting the driver's arousal level (that is, the arousal level) calculated in S150 (hereinafter, the uncorrected arousal level is referred to as an uncorrected arousal level). .

  In S200, the speaker 11 issues a warning or the like based on the corrected awakening level corrected in S190 or the uncorrected awakening level when it is determined in S180 that the driver's line of sight is other than downward vision. A warning process for outputting an audio signal to the speaker 11 is executed. Specifically, in the present embodiment, if the arousal level is greater than a predetermined first threshold value, the speaker 11 is alerted to urge the driver to rest, and the arousal level is assumed to be greater than the first threshold value. If it is larger than the preset second threshold value, a warning is issued from the speaker 11 to stop driving. In addition, the warning said here gives a message stronger than attention, such as a sound louder than attention, to a driver | operator.

Thereafter, the process returns to S110.
<Downward view detection processing>
Next, the downward vision detection process executed in the previous sleepiness warning process will be described.

Here, FIG. 3 is a flowchart showing a processing procedure of the downward vision detection process.
When the downward vision detection process is started in S170 in the previous drowsiness warning process, first, in S310, the boundary between the lower eyelid of the driver and the eyeball is determined from the area around the eye binarized in the previous S160. An approximate curve (fd) indicating the contour shape of the lower eyelid is calculated.

  Specifically, in the present embodiment, as shown in FIG. 8, the approximate curve (fd) is calculated so as to pass through a pixel located at the boundary between the lower eyelid and the eyeball between the eyelid and the eyeball. A known smoothing process is executed on the approximate curve (fd).

  In subsequent S320, it is determined whether or not the approximate curve (fd) calculated in S310 is convex downward. If the result of determination is that the approximate curve (fd) is convex downward, S330 Proceed to

In S330, a downward view flag indicating that the driver's line of sight is a downward view in which the driver is looking downward from the gaze axis is set, and the process returns to S180 of the drowsiness warning process.
If it is determined in S320 that the approximate curve (fd) calculated in S310 is not convex downward (that is, a straight line or convex upward), the process proceeds to S340, and S340 Then, it is normal to indicate that the direction of the driver's line of sight is a normal view other than a downward view (that is, a case where the line of sight is directed toward the gazing point or a mirror in the mounted vehicle is viewed). The visual flag is set, and the process returns to S180 of the drowsiness warning process.

That is, in the drowsiness detection device 1, from the light source 13 arranged at the second arrangement position where irradiation light can be emitted so that a shadow formed on the boundary between the lower eyelid of the driver and the eyeball is projected into the eyeball, While irradiating the driver's face with irradiation light, a shadow 12 formed at the boundary between the driver's lower eyelid and the eyeball is photographed by the camera 12 arranged at the first arrangement position.
[Effect of the embodiment]
As described above, the sleepiness of the present embodiment, in which the shadow formed in the driver's lower eyelid and the eyeball and reflected in the driver's eyeball is photographed by the camera 12 arranged at the first arrangement position. According to the detection device 1, the brightness difference at the boundary between the driver's lower eyelid and the eyeball, that is, the contour shape of the driver's lower eyelid can be made clear in the captured image taken by the camera 12.

  In particular, according to the drowsiness detection device 1 of the present embodiment, since the light source 13 is disposed below the camera 12, it is formed at the boundary between the driver's lower eyelid and the eyeball when irradiated with irradiation light. Thus, the shadow projected in the driver's eyeball (that is, the shadow representing the contour shape of the driver's lower eyelid) can be captured in the captured image more clearly.

Therefore, according to the drowsiness detection device 1, the contour shape of the driver's lower eyelid can be accurately extracted from the photographed image.
Here, FIG. 4 shows the difference between the shape of the eyes when drowsiness (ie, the region surrounded by the upper eyelid and the lower eyelid) and the shape of the eyes (eyelid) when viewed from below. It is an experimental result. As shown in FIG. 4, the inventors of the present invention have a lower eyelid contour shape downward (that is, the approximate curve (fd) is lower than that when sleepiness occurs in a downward view. The result of becoming convex.

  Therefore, according to the drowsiness detection device 1, when the approximate curve (fd) is convex downward, it is determined that the driver is looking downward, thereby improving the detection accuracy of the driver looking downward. Can be made.

  Then, according to the drowsiness detection device 1, in the case of the downward view, the wakefulness is corrected so that the decrease in the wakefulness caused by the downward view is offset, so that the driver's sleepiness level is adjusted. Therefore, it is possible to improve the detection accuracy of the driver's drowsiness (that is, the arousal level).

According to the drowsiness detection device 1, since the camera 12 is disposed at a position where meters such as a speedometer are disposed and the light source 13 is disposed on an extension line of the steering column in the steering wheel, The driver's sleepiness can be detected without causing any inconvenience.
[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects.

For example, the first arrangement position in the drowsiness detection device 1 of the above embodiment is a position where a speedometer or a rotational speedometer is provided, but may be in the instrument panel,
It may be on the instrument panel. In other words, the first arrangement position is a position where a shadow formed at the boundary between the lower eyelid and the eyeball of the driver can be photographed, and any position within the range sandwiched between the gaze axis and the lower axis. It may be a position.

Furthermore, although the light receiving part of the camera 12 in the above embodiment is composed of a CCD element, the light receiving part may be composed of a CMOS element.
In the above-described embodiment, the camera 12 receives the imaging signal from the image processor 10 and captures the captured image. However, the camera 12 may capture the captured image without receiving the imaging signal. However, in this case, it is necessary to store the captured image in the camera 12 and the image processor 10 acquires the stored captured image.

  And although the 2nd arrangement position in the drowsiness detection apparatus 1 of the said embodiment was made on the extension line of the steering column in a steering wheel, it is not restricted to this. For example, it may be a position where a speedometer or a rotational speedometer is provided, or may be in the instrument panel. That is, the second arrangement position is a position where a shadow formed on the boundary between the lower eyelid and the eyeball of the driver can be projected in the driver's eyeball and is below the lower axis. It may be a position.

  In the above-described embodiment, the light source 13 receives the light emission signal from the image processor 10 and emits the irradiation light. However, the light source 13 may emit the irradiation light without receiving the light emission signal. However, in this case, it is desirable that the irradiation light is irradiated by operating a switch or the like.

  In the drowsiness detection device 1 of the above embodiment, the contour shape of the lower eyelid of the driver is extracted based on the photographed image taken by the camera 12, but the lower eyelid is irradiated with laser light and reflected by the laser light. The outline shape may be recognized. In this case, the camera 12 may not be provided in the drowsiness detection device 1.

It is a block diagram which shows schematic structure of a drowsiness detection apparatus. It is a flowchart which shows the process sequence of a drowsiness warning process. It is a flowchart which shows the process sequence of a downward vision detection process. It is an eye image taken in an experiment to determine the difference in contour shape of the lower eyelid when drowsiness occurs and when viewed from below. It is explanatory drawing for demonstrating the arrangement position of a camera and a light source. It is explanatory drawing for demonstrating the outline | summary of a downward axis | shaft. It is explanatory drawing for demonstrating the detection of blink, ie, calculation of arousal level. It is explanatory drawing which shows the approximated curve of a lower eyelid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sleepiness detection apparatus 10 ... Image processor 10a ... ROM 10b ... RAM 10c ... CPU 11 ... Speaker 12 ... Camera 13 ... Light source

Claims (8)

Photographing means for photographing a photographed image including the face of the driver of the vehicle;
Contour shape extraction means for extracting a contour shape of the lower eyelid of the driver based on a photographed image photographed by the photographing means;
Based on the contour shape extracted by the contour shape extraction means, a downward vision detection means for detecting a downward vision in which the driver directs his / her gaze below a gaze to a gazing point preset in front of the vehicle;
Based on the driver's arousal level estimated from the captured image captured by the imaging unit, when the downward vision is detected by the downward vision detection unit, a decrease in the arousal level due to the downward vision is offset. A drowsiness detection device comprising: drowsiness detection means for correcting the arousal level so as to detect drowsiness of the driver based on the awakening level,
The photographing means includes
A drowsiness detection device, which is formed at a first arrangement position formed by a boundary between the lower eyelid of the driver and an eyeball and capable of photographing a shadow reflected in the eyeball of the driver. The first arrangement position where the photographing means is arranged is
Driving gaze axis that is the direction of the driver's gaze to the gaze point, the driver's eyes when the driver is gazeing to the gaze point, and the lowest position of the lower eyelid, 2. The vehicle according to claim 1, wherein the vehicle is located in a specified region that is a region in the vehicle sandwiched between a lower shaft that is a straight line connected on a cross section including a full length direction and a height direction of the vehicle. Drowsiness detection device. The first arrangement position where the photographing means is arranged is
The drowsiness detection device according to claim 1, wherein the drowsiness detection device is inside an instrument panel or a meter of the vehicle. Irradiating means for irradiating irradiation light toward the driver's face;
The irradiation means includes
The irradiation light is arranged at a second arrangement position such that a shadow formed by a boundary between a lower eyelid and an eyeball of the driver is projected into the eyeball. The drowsiness detection device according to claim 1.   The drowsiness detection device according to claim 4, wherein the second arrangement position where the irradiation unit is arranged is lower than the first arrangement position where the photographing unit is arranged. Irradiating means for irradiating irradiation light toward the driver's face;
A contour shape extracting means for extracting a contour shape of the lower eyelid of the driver based on the light reflected on the face of the driver;
Based on the contour shape extracted by the contour shape extraction means, a downward vision detection means for detecting a downward vision in which the driver directs his / her gaze below a gaze to a gazing point preset in front of the vehicle;
Based on the driver's arousal level estimated from the captured image captured by the imaging unit, when the downward vision is detected by the downward vision detection unit, a decrease in the arousal level due to the downward vision is offset. A drowsiness detection device comprising: drowsiness detection means for correcting the arousal level so as to detect drowsiness of the driver based on the awakening level,
The irradiation means includes
Drowsiness detection characterized by being arranged at a second arrangement position such that a shadow formed on the boundary between the lower eyelid and the eyeball of the driver is projected into the eyeball by irradiating the irradiation light apparatus. The second arrangement position where the irradiation means is arranged is
A straight line connecting the driver's eyes when the driver is looking toward the gazing point and the lowest position of the lower eyelid on a cross section including the full length direction and the height direction of the vehicle The drowsiness detection device according to any one of claims 4 to 6, wherein the drowsiness detection device is located below the lower axis. The second arrangement position where the irradiation means is arranged is
The drowsiness detection device according to any one of claims 4 to 7, wherein the drowsiness detection device is on an extension line of a steering column in a steering wheel provided in the vehicle.

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