JP2013105263A - Vehicle arousal degree detection device and vehicle alarm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle arousal degree detection device and a vehicle alarm device using the same which can detect reduction in an arousal degree of a driver at an early stage.SOLUTION: The vehicle arousal degree detection device comprises: visual line detection means 12, 21 which detects a visual line location of a driver of a vehicle 1; and arousal degree determination means 20 which determines that an arousal degree of the driver is low when the visual line location of the driver detected by the visual line detection means 12, 21 is lower than a reference position.

Description

  The present invention relates to a vehicle wakefulness detection device that detects the wakefulness of a vehicle driver and a vehicle alarm device using the same.

  In recent years, various techniques for detecting a decrease in a driver's arousal level during driving of a vehicle have been developed. Examples of such techniques include Patent Document 1 and Patent Document 2.

  The technique of Patent Document 1 extracts a pupil from an image obtained by photographing the face of a detection target person, and determines the arousal level based on the state of the pupil. For example, if this pupil cannot be extracted, it is determined that the eyelid is closed, or if the height position of the pupil in the captured image is lower than a predetermined value, the face is depressed and the driver is awakened. Detect a decrease in degree.

  The technique of Patent Literature 2 creates a frequency distribution pattern of gaze direction data by accumulating the measured driver's gaze movements, and compares this frequency distribution pattern with the same pattern at the time of awakening. Thus, a decrease in the driver's arousal level is detected.

JP 7-249197 A Japanese Patent Laid-Open No. 9-20157

By the way, the purpose of detecting the driver's arousal level is that if the driver's arousal level decreases, the risk of adverse effects on driving operations increases. For example, to be aware of this and encourage appropriate responses. Usually, the lower the arousal level, the stronger the influence on driving.
In the technique of Patent Document 1, after the driver's eyelids are closed or the arousal level is greatly decreased after the face is depressed, the level of arousal level is determined early in order to determine a decrease in the driver's level of arousal level. It is not possible to detect a decrease in.

Further, in the technique of Patent Document 2, since the movement of the driver's line of sight is measured and the measured movement of the line of sight is accumulated to create the frequency distribution pattern of the line-of-sight direction data, it takes time to create the pattern. In other words, it takes time from the start of measurement to the determination of a decrease in arousal level, and as a result, the arousal level cannot be detected early.
The present invention has been made in view of the above problems, and provides a vehicle arousal level detection device and a vehicle alarm device using the same, which can detect a decrease in the driver's awakening level at an early stage. The purpose is to provide.

  (1) In order to achieve the above object, a vehicle arousal level detection apparatus according to the present invention includes a line-of-sight detection unit that detects a line-of-sight position of a driver of the vehicle, and the driver's detection detected by the line-of-sight detection unit. Awakening degree determining means for determining that the driver's awakening level is lowered when the line-of-sight position is lower than the reference position is provided.

  (2) The line-of-sight detection unit detects a line-of-sight position of the driver's right eye and a line-of-sight position of the driver's left eye, respectively, and the arousal level determination unit detects the line-of-sight position of the right eye and the left eye When the difference (gap) from the eye gaze position is larger than a predetermined value, it is preferable to determine a decrease in the driver's arousal level.

  (3) The line-of-sight detection means extracts an image detection means for detecting the driver's face image, and extracts the driver's eyes and pupils in the eyes from the face image detected by the image detection means. It is preferable that the apparatus has gaze position calculation means for calculating the vertical relative position of the pupil with respect to the eye as the gaze position.

  (4) The line-of-sight detection means extracts the driver's eyes from the face image detected by the image detection means, and changes the position of the driver's face from the change in the vertical relative position of the eyes in the face image. A whistling degree judging means for judging a whispering degree is provided, and the awakening degree judging means changes the reference position higher as the whispering degree becomes larger according to the whispering degree judged by the whispering degree judging means. Is preferred.

  (5) Vehicle speed detection means for detecting the vehicle speed of the vehicle and road shape determination means for determining the shape of the road on which the vehicle travels. The awakening degree determination means, when the determination start condition is satisfied, The determination start condition is that the vehicle speed detected by the vehicle speed detecting means is equal to or higher than a predetermined vehicle speed, and the shape of the road determined by the road shape detecting means is linear (bent. Is not preferred).

  (6) Further, the vehicle alarm device of the present invention warns the driver when a decrease in the driver's arousal level is determined by the above-described vehicle arousal level detection device and the arousal level determination unit. And an alarm means.

  (1) Therefore, in the vehicle wakefulness detection device according to the present invention, the wakefulness determination means determines a decrease in the driver's wakefulness when the driver's line-of-sight position is lower than the reference position. It is possible to detect a decrease in the arousal level. In addition, since a decrease in arousal level can be detected simply by using the driver's line-of-sight position detected by the line-of-sight detection means, the configuration can be simplified.

  (2) If the difference between the gaze position of the right eye and the gaze position of the left eye is greater than a predetermined value, the arousal level determination means can determine the decrease in the driver's arousal level. Further, it is possible to detect a decrease in arousal level by determining a so-called vertical perspective in which the difference between either one of the left eye and the other eye is greater than a predetermined value. Further, since the decrease in the arousal level is determined even when the line-of-sight positions of both eyes of the driver do not decrease at the same time, the detection accuracy of the arousal level can be improved.

(3) If the driver's line-of-sight position is configured to be the vertical relative position of the pupil with respect to the eye, an initial symptom of a decrease in alertness in which the line of sight falls while the face is facing forward is detected. It is possible to detect a decrease in arousal level.
(4) If the reference position is changed to be higher as the driver's face's degree of whispering increases, it is possible to appropriately determine a decrease in the degree of arousal according to the degree of whirling even with respect to the detected change in the gaze position. .

(5) The condition for starting the determination of arousal level is that when the road is configured to be straight (not bent), the vehicle is traveling on a straight road where a decrease in the arousal level is likely to occur. Since the driver's line-of-sight position is stable with little change compared to when driving on a curved road, the line-of-sight position corresponding to a decrease in arousal level is easy to detect. For this reason, it is possible to accurately detect a decrease in the driver's arousal level in a situation in which a decrease in the arousal level is likely to occur.
Also, if the detection start condition of the arousal level is configured such that the vehicle speed is equal to or higher than the predetermined vehicle speed, it is possible to detect a decrease in the driver's arousal level at an early stage even during traveling at a high vehicle speed and a high risk level. .

(6) Since the vehicle alarm device of the present invention is provided with an alarm means for alarming the driver of a decrease in the arousal level, the driver is alerted to the decrease in the driver's arousal level detected at an early stage. Such an appropriate response can be promoted.
Also, when the driver's line-of-sight position is lowered, the point where the driver is gazing while traveling is moved forward, and the driver's sensitivity to the deviation in the direction of the road may be dull and the vehicle may meander. However, it is possible to prompt the driver to take an appropriate action for driving by notifying the decrease in the arousal level by an alarm.

1 is a configuration diagram illustrating a vehicle arousal level detection device and an alarm device according to an embodiment of the present invention. It is a figure explaining the detection of a driver | operator's alertness fall by the alertness detection apparatus of the vehicle concerning one Embodiment of this invention, (a) is a side view of a vehicle interior principal part, (b), (c) and (D) is a front view of the driver's face image, and (e) and (f) are views showing the driver's line of sight corresponding to (b) and (c). It is a figure explaining detection of a look position in a wakefulness detection device of vehicles concerning one embodiment of the present invention, and is an enlarged view of a driver's eyes. It is a flowchart which determines the start condition of arousal level determination in the arousal level detection apparatus of the vehicle concerning one Embodiment of this invention. It is a flowchart which shows the warning of the driver | operator by the determination of the arousal level fall in the arousal level detection apparatus of the vehicle concerning one Embodiment of this invention, and the alarm device of a vehicle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<One Embodiment>
[Constitution]
First, the configuration of a vehicle alertness detection device and a vehicle alarm device according to an embodiment will be described. The vehicle according to the present embodiment is a so-called large or medium-sized automobile such as a truck or a bus.

  As shown in FIG. 1, the vehicle 1 includes a vehicle speed sensor (vehicle speed detection means) 11, a driver monitoring camera 12, an HMI (Human Machine Interface, alarm means) 18, and these components 11, 12 and 18. Each has a wakefulness detection ECU 15 connected thereto. The arousal level detection ECU 15 includes a road shape determination unit (road shape determination unit) 16, a condition determination unit 17, and an arousal level determination unit 20 having a line-of-sight position detection unit 21.

The vehicle speed sensor 11 detects the vehicle speed V of the vehicle 1. As the vehicle speed sensor 11, a sensor that detects the rotational speed of the driven wheel or a sensor that detects the rotational speed of the crankshaft of the engine can be applied.
Information on the vehicle speed V detected by the vehicle speed sensor 11 is transmitted to the arousal level detection ECU 15.

A driver monitoring camera (hereinafter also simply referred to as a camera) 12 captures a driver's face. Hereinafter, the camera 12 will be described with reference to FIG.
As shown in FIG. 2 (a), the camera 12 is located in front of the driver's seat, near the front window glass 103 on the front lower edge 101a of the ceiling 101 of the cab 100, or on the upper part of the dash panel 102. It arrange | positions so that the part in which the driver | operator's face seated in the driver's seat is located may be image | photographed. In FIG. 2A, the driver's line of sight e is indicated by a one-dot chain line.

The camera 12 captures a driver's face image as shown in FIGS.
Information on the driver's face image taken by the driver monitoring camera 12 is transmitted to the arousal level detection ECU 15.
In the present embodiment, information of the driver's face image captured by the camera 12 is processed by the line-of-sight position detection unit 21 of the arousal level detection ECU 15.

  The line-of-sight position detection unit 21 detects the line-of-sight position of the driver of the vehicle 1. The line-of-sight position detection unit 21 includes an image detection unit (image detection unit) 21a, a line-of-sight position calculation unit (line-of-sight position calculation unit) 21b, and a whirling degree determination unit 21c.

Hereinafter, detection of the driver's gaze position by the gaze position detection unit 21 will be described.
The image detection unit 21 a detects a face image from image information captured by the camera 12. The image detection unit 21a performs, for example, binarization processing, feature point extraction processing, and the like to extract a face outline, a nostril, and an eye, and based on these extracted parts, for example, an area surrounded by the outline Can be detected as a face image.

  The line-of-sight position calculation unit 21b extracts the driver's eyes (the region surrounded by the upper eyelid and the lower eyelid) and the pupil in the eye from the face image detected by the image detection unit 21a, and the pupil of the eye relative to the eye is extracted. The vertical relative position is calculated as the line-of-sight position. Hereinafter, detection of the line-of-sight position will be described with reference to FIGS. 2 (b) to 2 (d) and FIG. 3.

First, detection of the line-of-sight position of the driver facing the front as shown in FIGS. 2B and 2C will be described.
FIG. 3 is an enlarged view showing the periphery of one eye of the driver shown in FIG. Incidentally, in FIG. 2 (b) shows the driver's face image is the position of the pupil IP during wakefulness, during 3, the maximum distance H _E of the upper and lower eyelids, from the lower eyelid to the center of the pupil IP The distance H ₁ is shown.

The line-of-sight position calculation unit 21b calculates the driver's line-of-sight position H using the following equation (1) based on these distances H _E and H ₁ .
_{H = H 1 / H E ···} (1)
That is, it can be said that the line-of-sight position calculation unit 21b calculates the height position (vertical relative position) of the pupil IP in the open eye region as the line-of-sight position H. The line-of-sight position detection unit 21 detects the line-of-sight position using the calculation process performed by the line-of-sight position calculation unit 21b.

  FIG. 2C shows a driver's face image when the arousal level is lowered. The line-of-sight position shown in FIG. 2C is lower than the line-of-sight position shown in FIG. Accordingly, the line-of-sight position detection unit 21 detects the driver's line-of-sight position shown in FIG. 2C lower than the driver shown in FIG.

FIG. 2 (e) shows the line of sight e ₁ of the driver shown in FIG. 2 (b), the distance between the point P ₁ to point P ₀ and the line of sight e ₁ of the driver intersects the vehicle 1 in front of the travel path L ₁ is shown. Also, FIG. 2 (f) shows the driver's line of sight e ₂ shown in FIG. 2 (c), and the point P ₂ to the point P ₀ and the line of sight e ₂ of the driver intersects the vehicle 1 in front of the travel path The distance L ₂ is shown. It can be said that the distance L ₁ and the distance L ₂ indicate how far the driver of the vehicle 1 looks.

  Therefore, if a high line-of-sight position is detected by the line-of-sight position detection unit 21, the driver is looking forward and far from the vehicle 1, and if a low line-of-sight position is detected by the line-of-sight position detection unit 21, the driver Is looking in front of the vehicle 1 and in the vicinity of the vehicle 1.

In the present embodiment, when the driver's face is facing left and right, the driver's line-of-sight position is not detected. The gaze position detection unit 21 determines whether or not the face is facing left and right.
The line-of-sight position detection unit 21 determines whether the driver's face is facing the front based on the face image detected by the image detection unit 21a. This determination is based on the face image detected by the image detection unit 21a, for example, by performing binarization processing or feature point extraction processing to calculate the angle at which the driver's face turns to the left or right with respect to the vehicle front direction. If this angle (also referred to as a face orientation angle) is within a predetermined angle, it is determined that the driver's face is facing the front. The predetermined angle here refers to an angle corresponding to the face orientation angle of the driver who faces the front of the vehicle 1 such as a range of ± 10 degrees.

  If the driver's face is facing left or right, the angle at which the driver's face faces the front direction of the vehicle is a predetermined angle or more. That is, the line-of-sight position detection unit 21 determines that a driver whose face direction angle is equal to or greater than a predetermined angle is not facing the front. Therefore, such a driver's line-of-sight position is not detected.

Further, the line-of-sight position detection unit 21 determines the direction of the driver's face in the vertical direction by using the whirling degree determination unit 21c.
FIG. 2B shows a face image in which the driver faces the front, that is, the face is not oriented in the vertical direction or the horizontal direction, and the vertical length of the driver's face F (from the lower end of the chin). The length to the top of the head) H _F and the length H _S from the lower end of the face F (the lower end of the chin) to the pupil IP are shown. This length H _S is the height position H _S (vertical reference position) of the pupil IP with reference to the lower end of the face F when awakened.

The whispering degree determination unit 21c stores this length H _S experimentally or empirically in advance, or stores and learns the length H _S cumulatively, and uses this average value as the length H _S. Can do.
The whispering degree determination unit 21c determines the vertical direction of the driver's face using these lengths H _F and H _S. Hereinafter, the determination of the orientation of the face F will be described by exemplifying a case where the driver's face F faces down (crawls).

FIG. 2 (d) shows the driver with the face F crawling, and the position of the pupil IP is lowered by H ₂ from the height position H _S of the pupil relative to the lower end of the face F at the time of awakening. Indicates what is.
Face down degree determination unit 21c, based on these positions H _S, H _2, and calculates the vertical orientation (face down degree) H _theta face using Equation (2) below.
H _θ = H ₂ / H _S (2)

The direction H _θ calculated by the equation (2) has a correlation with the vertical direction of the face F. If the direction H _θ is zero, the driver's face F faces the front direction, and the direction H _θ is The driver's face F crawls as it grows larger. Focusing on this characteristic, face down degree determination unit 21c determines face down degree of the driver's face from the face down degree H _theta calculated by the sight line position detecting unit 21. Accordingly, the line-of-sight position detecting section 21, for the driver orientation H _theta has a predetermined value, for example, the face is determined to vertical orientation of the face, such as look down there, the reference position according to such line-of-sight position change. The change of the reference position will be described later. Here, the predetermined value refers, in advance set value to eliminate the orientation H _theta when vertically face faces minutely.

  As described above, since the line-of-sight position detection unit 21 detects the line-of-sight position based on the driver's face image captured by the camera 12, the line-of-sight detection unit is configured by the driving monitoring camera 12 and the line-of-sight position detection unit 21. . The line-of-sight detection means detects the line-of-sight position for each of the driver's left eye and right eye, and determines the larger value of the line-of-sight position (the value of the line of sight of the eye looking far). It is detected as the line-of-sight position of the driver's eyes. This is because attention is paid to the fact that the driver recognizes information from the eye with the larger eye-gaze position value than information from the eye with the smaller eye-gaze position value.

  The arousal level detection ECU 15 includes a road shape determination unit 16, a condition determination unit 17, and an awakening level determination unit 20, and performs all processes related to detection of the arousal level of the vehicle. The arousal level detection ECU 15 is an electronic control unit configured as an LSI device or an embedded electronic device in which a microprocessor, a ROM, a RAM, and the like are integrated, for example.

  The road shape determination unit 16 determines a road shape on which the vehicle 1 travels. Examples of the determined road include a straight road (a road that is not bent) and a curved road. Note that the straight road refers to a road having a shape change with little shape change, such as a road having a shape that does not substantially require a driver's conscious steering operation when traveling along the road.

As the road shape determination unit 16, a combination of a digital map and GPS, or a unit that processes an image captured by a camera that captures the front of the vehicle 1 can be applied.
For example, when a combination of a digital map and GPS is used as the road shape determination unit 16, the position of the vehicle 1 is specified by applying the position of the vehicle 1 detected by the GPS to the digital map, and the position of the vehicle 1. By estimating the traveling direction of the vehicle 1 from the history, the road shape ahead of the vehicle 1 can be determined.

  In addition, when the road shape determination unit 16 that applies image processing to a road taken by a camera is applied, a road along a road such as a lane boundary line or a center line indicated by a white line on the road from the shot image is used. By extracting by image processing, the road shape ahead of the vehicle 1 can be determined.

  The condition determination unit 17 determines a condition (also referred to as a determination start condition) for starting determination of arousal level reduction described later. This condition is determined using the vehicle speed information detected by the vehicle speed sensor 11 and the road shape determined by the road shape determination unit 16.

The determination start condition determined by the condition determination unit 17 is that the vehicle speed V of the vehicle 1 is higher than the predetermined vehicle speed V _{p and} the road shape on which the vehicle 1 travels is a straight line. Here, the predetermined vehicle speed V _p is set in advance as a vehicle speed, for example, 60 km / h, as the vehicle speed when the vehicle travels in a situation where there is little change or attention to be paid around the straight road. This determination start condition is satisfied in a situation where the driver's line-of-sight position is stable and the arousal level is likely to decrease, for example, when the vehicle 1 is traveling on a motorway or an expressway.
That is, the condition determining unit 17, the change is small shape of the road, and when the vehicle speed V at the time of vehicle running is higher than a predetermined vehicle speed V _p in is small situations should direct change and attention to the peripheral, It is determined that the determination start condition is satisfied.

Here, a decrease in the driver's arousal level will be described.
Generally, when the driver's arousal level starts to decrease during driving, the line of sight starts to decrease. That is, it can be said that there is a correlation between a decrease in the driver's arousal level and a decrease in the line-of-sight position.
For example, the point at which the driver is gazing when the wakefulness level is lower is closer to the vehicle side than the point ahead of the vehicle at which the driver is gazing at the time of wakefulness (when the degree of wakefulness is high). Such fluctuation characteristics of the line-of-sight position can be observed even when the degree of arousal starts to decrease.

  The vehicle wakefulness detection device of the present invention detects a driver's wakefulness drop at an early stage by using the above-described line-of-sight position fluctuation characteristics observed even when the wakefulness drop starts. That is, when the arousal level determination unit 20 determines that the arousal level has decreased, the arousal level detection ECU 15 detects the decrease.

  The arousal level determination unit 20 determines a decrease in the driver's arousal level. This determination is started when it is determined by the condition determination unit 17 that the determination start condition is satisfied, and is determined based on the driver's gaze position information detected by the driver monitoring camera 12 and the gaze position detection unit 21. The

  Specifically, the arousal level determination unit 20 determines that the driver's arousal level is reduced when the gaze position of both eyes of the driver is lower than the reference position. Here, the reference position is a position in which the line-of-sight position of a driver who is awake (not sleepy) is set in advance. As the reference position, for example, the position of the pupil IP in FIG. 3 showing an enlarged view of the periphery of the driver's eye at awakening, that is, the vertical relative position of the pupil with respect to the eye is set in advance. The reference position is set in advance according to the vehicle speed so as to increase as the vehicle speed increases.

Further, the arousal level determination unit 20 changes the reference position when it is determined by the whispering degree determination unit 21c that the face of the driver has a vertical direction such as a whispering face.
That is, the awakening level determination unit 20 increases the reference position as the degree of whispering increases. This is based on the assumption that the line of sight is lowered even if the gaze position is sufficiently high when the face is whispered. It is intended to distinguish it from the situation in which it is suitable.

For example, the driver can gaze at a distant place if his eyes are looking up even if his face is crawling. That is, even if the face is facing down, if the line-of-sight position is high, it is possible to gaze at the same point as the driver at the time of awakening with the face facing forward without having an angle in the vertical direction.
Paying attention to the characteristics of the face orientation and the line-of-sight position, the arousal level determination unit 20 changes the reference position to be higher as the driver's face turns (the face turns downward).

In other words, the arousal level determination unit 20 uses the line-of-sight position corresponding to the reference distance L when the distance between the point at which the driver's line of sight is to be watched and the position of the vehicle 1 is the reference distance L. Change the reference position so that
That is, the reference distance L increases as the vehicle speed increases. If the vehicle speed is constant, the reference distance L is constant regardless of the vertical direction of the face or body.

  In addition, when the difference between the gaze position of the right eye of the driver and the gaze position of the left eye becomes greater than a predetermined value, the arousal level determination unit 20 determines a decrease in the driver's arousal level. The difference (gap) between the gaze position of the right eye and the gaze position of the left eye here means the difference between the value of the gaze position of the right eye and the value of the gaze position of the left eye, and the predetermined value is When the arousal level is greatly reduced, the difference between the gaze position of the left eye and the value of the gaze position of the right eye in the case where a so-called up-down perspective that shifts up and down from the right eye pupil and the left eye pupil occurs is set in advance. The

When the arousal level determination unit 20 determines that the arousal level is decreased, the arousal level detection ECU 15 detects a decrease in the driver's arousal level and issues an alarm instruction to the HMI 18.
The HMI 18 is an interface between the driver and the vehicle equipment, and alerts the driver of the vehicle 1. As the HMI 18, a speaker, a seat vibration device that vibrates the driver's seat, or the like can be used.
When an alarm instruction is issued from the arousal level detection ECU 15 based on the determination of a decrease in the arousal level, the HMI 18 warns the driver of a decrease in the arousal level by ringing a speaker or vibrating the driver's seat.

[Action / Effect]
Since the configuration of the vehicle alertness detection device and the alarm device according to the embodiment of the present invention is configured as described above, the condition determination unit 17 determines the start condition of the alertness decrease determination as shown in FIG. A flow is performed. This flow is always performed periodically while the vehicle 1 is traveling.

In step S2, it is determined whether the shape of the road (traveling road) on which the vehicle 1 travels is a straight line. If the traveling road is linear, the process proceeds to step S4, and if the traveling road is not linear, the process proceeds to step S9.
In step S4, it determines whether the vehicle speed V of the vehicle 1 is higher than the predetermined vehicle speed V _p. The vehicle speed V is shifted to the step S4 is higher than a predetermined vehicle speed V _p, the vehicle speed V is shifted to the step S9 is equal to or less than a predetermined vehicle speed V _p.

In step S6, it is determined whether the driver's face is facing front, that is, whether the driver's face is not facing left or right. If it faces the front, it will transfer to step S8, and if it does not face the front, it will transfer to step S9.
In step S8, a determination start condition for lowering the arousal level is satisfied. Then, this control cycle ends (end).
Further, in step S9, the determination start condition relating to the reduction in the arousal level is not satisfied. Then, this control cycle ends (end).

Next, with reference to FIG. 5, a flow showing determination of a driver's arousal level reduction by the arousal level determination unit 20 and a warning to the driver by the HMI 18 will be described.
In step S10, information on the line-of-sight position is acquired. In addition, the information of this gaze position acquires the gaze position information of each of the right eye and the left eye.
In step S20, it is determined whether the line-of-sight position of both eyes is lower than the reference position. If the line-of-sight position of both eyes is lower than the reference position, the process proceeds to step S30. If the line-of-sight position of both eyes is equal to or greater than the reference position, the process proceeds to step S25.

In step S25, it is determined whether the difference between the value of the gaze position of the right eye and the value of the gaze position of the left eye is greater than a predetermined value. If it is larger than the predetermined value, the process proceeds to step S30, and if it is equal to or smaller than the predetermined value, this control cycle is ended.
In step S30, a decrease in the driver's arousal level is determined.
In step S40, the driver is warned. Then, this control cycle ends (end).

  Therefore, according to the vehicle wakefulness detection device of the present invention, the wakefulness determination unit 20 determines a decrease in the driver's wakefulness when the driver's line-of-sight position is lower than the reference position. It is possible to detect a decrease in the arousal level. Further, since the decrease in the arousal level can be detected only by using the driver's line-of-sight position detected by the line-of-sight detection unit 21, the configuration can be simplified.

  When the difference between the value of the right eye gaze position and the value of the left eye gaze position is greater than a predetermined value, the arousal level determination unit 20 determines the decrease in the driver's arousal level. By determining a so-called up-down perspective in which the difference between the value of the eye position of any one of the eyes and the value of the eye position of the other eye is greater than a predetermined value, it is possible to detect a decrease in the arousal level. Further, since the decrease in the arousal level is determined even when the line-of-sight positions of both eyes of the driver do not decrease at the same time, the detection accuracy of the arousal level can be improved.

Since the driver's line-of-sight position is the vertical relative position of the pupil with respect to the eye calculated by the line-of-sight position calculation unit 21b, the wakefulness determination unit 20 detects an initial symptom of a decrease in wakefulness such as before the eyelid closes. Therefore, it is possible to detect a decrease in arousal level at an early stage.
Since the reference position is changed according to the degree of the driver's face, it is possible to appropriately determine the reduction in the arousal level even when the line-of-sight position changes according to the degree of the person's face. In addition, it is possible to discriminate between a driver who is crawling while monitoring a distant place and a driver whose face is crawling and whose line of sight is lowered, and the detection accuracy of the arousal level can be improved.

Since the determination of arousal level is based on the condition that the shape of the road is a straight line, when driving on a straight road where the awakening level is likely to decrease, However, since the gaze position by the driver is stable with little change, it is easy to detect the gaze position according to the decrease in the arousal level. For this reason, it is possible to accurately detect a decrease in the driver's arousal level in a situation in which a decrease in the arousal level is likely to occur.
In addition, since the detection of the arousal level is based on the condition that the vehicle speed V is higher than the predetermined vehicle speed V _p , even when the vehicle speed V is high and the danger level is high, the driver's awakening level is detected early. can do.

According to the vehicle alarm device, since the driver is provided with the HMI 18 that warns the driver of a decrease in the arousal level, the driver is alerted to the decrease in the driver's arousal level detected at an early stage, and an appropriate response to driving is taken. Can be urged.
Further, when the driver's line-of-sight position is lowered, the point at which the driver is gazing while traveling is moved forward, and the driver's sensitivity to the deviation in the direction of the road may be dull and the vehicle 1 may be meandered. However, it is possible to prompt the driver to take an appropriate action for driving by notifying the decrease in the arousal level by an alarm.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above-described embodiment, the detection of the gaze position of each of the right eye and the left eye of the driver is shown. However, the present invention is not limited to this, and the gaze position of either the right eye or the left eye may be detected. . According to this configuration, any one of the gaze positions can be used as the gaze position of both eyes, and the configuration of the gaze detection unit can be simplified. Further, step S25 in FIG. 5 for detecting the vertical perspective can be omitted. In this case, when it is determined to be the NO route in step S20 of FIG. 5, the control cycle is ended (end). Thereby, arousal level can be determined in a simple step.

Moreover, although what started the fall determination of an arousal level is shown when determination start conditions are satisfied, it replaces with said determination start condition, and the structure which performs the fall determination of an arousal level regularly always during the driving | running | working of the vehicle 1. It is good.
Moreover, although what showed the gaze position which is the up-down direction relative position of a pupil about each of a driver | operator's right eye and left eye was shown, the horizontal direction relative position of a pupil was detected about each right eye and left eye, and these You may detect what is called right-and-left strabismus which arises when arousal level falls by comparing a position. In this case, when the difference (distance) between the horizontal position of the right eye of the driver and the horizontal line-of-sight position of the left eye is greater than a predetermined value, the arousal level determination unit determines a decrease in the driver's arousal level. This predetermined value is the distance between the horizontal position of the left eye and the horizontal position of the right eye when a so-called left / right perspective that shifts to the left and right of the right eye pupil and the left eye pupil occurs when the arousal level is greatly reduced. Is preset as a value corresponding to.

  In addition, the determination of the driver's arousal level is shown by comparing the line-of-sight position with the reference position, but based on the line-of-sight position calculated by the line-of-sight position calculation unit, the driver's line of sight should Calculate the distance to the position, and compare this distance with a preset reference distance (the distance between the point where the driver's line of wakeful driver should gaze and the position of the vehicle) to determine the degree of arousal May be performed. In this case, if the vehicle speed is constant, a constant reference distance is used regardless of the face or body orientation.

  Moreover, although what uses a camera for the imaging | photography of a driver | operator's face was shown, in addition to this, you may irradiate the part where a driver | operator's face is located with light with a long wavelength, such as near-infrared light. In this case, since the irradiated near-infrared light or the like is reflected by the driver's pupil, the accuracy of extraction of the driver's pupil by the image detection unit can be improved.

  In addition, in the determination of the degree of driver's face by the whirling degree determination unit, the one using the upper and lower reference position and the height position of the pupil is shown, but this is not limited to this, not only at the time of awakening but also at the time of awakening degree reduction Also, the vertical length of the face and the height position of the pupil may be extracted, and the relative height of the pupil height to the vertical length of each face may be used as the vertical direction (degree of buzzing) of the face. . In this case, the driver's face crawls as the height of the pupil relative to the vertical length of the face becomes smaller. Further, although the height position of the pupil relative to the lower end of the face is shown as the vertical reference position, the height position of the pupil relative to the upper end of the face may be used. In this case, as the relative height of the pupil height relative to the vertical length of the face increases, the driver's face crawls.

  Further, the determination of the degree of the driver's face by using the degree of determination of the driver's face has been described using the vertical position of the pupil. However, the present invention is not limited to this, and the vertical position of the eye may be used. The eye position here refers to the center position in the vertical direction in the region surrounded by the upper eyelid and the lower eyelid. Accordingly, it can be said that the whispering degree determination unit determines the degree of whispering of the face from the change in the relative vertical position of the eyes in the face image.

  The vehicle alertness detection device of the present invention can be applied not only to large or medium-sized automobiles such as trucks or buses but also to small automobiles such as passenger cars.

1 Vehicle 11 Vehicle speed sensor (vehicle speed detection means)
12 Driver monitoring camera (Gaze position detection means)
15 Arousal level detection ECU
16 Road shape determination unit (road shape determination means)
17 Condition determining unit 18 HMI (alarm means)
20 Arousal level determination unit (wake level determination means)
21 Gaze position detection unit (gaze position detection means)
21a Image detection unit (image detection means)
21b Gaze position calculation unit (Gaze position calculation means)
21c Whispering degree determination unit (whipping degree determination means)
DESCRIPTION OF SYMBOLS 100 Driver's cab 101 Ceiling part 101a Front lower edge (of ceiling part) 102 Dash panel 103 Front window glass

Claims (6)

Line-of-sight detection means for detecting the line-of-sight position of the driver of the vehicle;
Awakening degree determination means for determining that the driver's arousal level is lowered when the driver's gaze position detected by the gaze detection means is lower than a reference position. Vehicle alertness detection device. The line-of-sight detection means detects the line-of-sight position of the driver's right eye and the line-of-sight position of the driver's left eye,
The wakefulness determination means determines a decrease in the driver's wakefulness when the difference between the line-of-sight position of the right eye and the line-of-sight position of the left eye is greater than a predetermined value. Item 4. The vehicle alertness detection device according to Item 1. The line-of-sight detection means includes
Image detecting means for detecting the driver's face image;
Eye-gaze position calculating means for extracting the driver's eye and the pupil in the eye from the face image detected by the image detecting means, and calculating the relative position of the pupil with respect to the eye as the eye-gaze position. The waking degree detection device for a vehicle according to claim 1 or 2, characterized by comprising: The line-of-sight detection means extracts the driver's eyes from the face image detected by the image detection means, and the degree of the driver's face whispering from a change in the vertical relative position of the eyes in the face image A whistling degree judging means for judging
4. The vehicle according to claim 3, wherein the awakening degree determination unit changes the reference position higher as the whispering degree increases in accordance with the whispering degree determined by the whispering degree determination unit. Arousal detection device. Vehicle speed detecting means for detecting the vehicle speed of the vehicle;
Road shape determining means for determining the shape of the road on which the vehicle travels,
The awakening level determination means starts the determination of the awakening level when the determination start condition is satisfied,
The determination start condition is characterized in that the vehicle speed detected by the vehicle speed detection means is equal to or higher than a predetermined vehicle speed, and the shape of the road determined by the road shape detection means is linear. 5. The vehicle arousal level detection device according to any one of 4 above. A vehicle wakefulness detection device according to any one of claims 1 to 5,
An alarm device for a vehicle, comprising: alarm means for alarming the driver when the driver's arousal level is determined to be lowered by the awakening level determining means.

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