JP2008059056A - Device for detecting arousal degree - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for detecting arousal degree which is low in cost and simple in constitution. <P>SOLUTION: The device for detecting arousal degree estimates the driving posture of an driver based on the weight distribution circumstances of a plurality of places of a driver's seat, and detects the degradation of the arousal of the driver, based on the estimation result. When degradation in the arousal is detected, the degradation of arousal is imparted to the driver. Also, the arousal detection device detects the degradation in the arousal of the driver, according to the number of times of the blinkings of the driver per unit time photographed by a camera device which photographs the blinking of the driver's eyes, and the degradation in arousal degree is notified to the driver, on the basis of the driving posture estimation when blinking cannot be detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for preventing drowsy driving. In particular, it is suitable for use in a device that complements arousal level detection by blink detection.

  There has been proposed an apparatus that detects that a driver has fallen asleep and is in a driving state and issues a warning for prompting the driver to awaken.

  For example, an apparatus that detects a driver's blink in order to detect a driver's arousal level is being put into practical use (see, for example, Patent Document 1). In order to realize such a device, it is indispensable to install a camera device capable of capturing an image near the driver's eyeball or eyelid with high accuracy in the cab.

  Or in the proposal of patent document 2, a driver's dozing driving state is detected by monitoring the lane departure of a vehicle, etc. using a camera apparatus.

JP-A-7-167618 JP-A-9-267660

  In the conventional technology described above, in order to introduce the arousal level detection device into the existing vehicle, it is necessary to modify the existing vehicle, such as providing a camera device for detecting the awakening level. In order to widely spread to existing vehicles, it is desirable that the number of remodeling points is as small as possible in order to reduce the apparatus introduction cost and period.

  Also, in the arousal level detection device that detects the driver's blink level by detecting the driver's blink, the outside scenery is a spectacle lens even when the driver is wearing sunglasses or wearing transparent glasses. There may be a situation in which it is difficult for the camera device to take a picture of the driver's blink due to, for example, being reflected in the image.

  Under such circumstances, it is desirable to detect a decrease in the driver's arousal level by means other than blink detection. For example, in the proposal of Patent Document 2, the driver's sleep state is detected by monitoring the lane departure of the vehicle using a camera device.

  However, in the means as in Patent Document 2, it is necessary to provide a camera device in addition to the blink detection camera device, which not only increases the cost of the device, but also secures the installation location of a plurality of camera devices. There is a problem that it becomes difficult.

  Therefore, it is desirable that the means for detecting a decrease in the driver's arousal level complementarily in a situation where blink detection is difficult is a means that has little influence on the device cost.

  The present invention has been made under such a background, and an object thereof is to provide a wakefulness detection device that is inexpensive and has a simple configuration.

  The present invention includes means for estimating a driver's driving posture based on weight distribution status at a plurality of locations in a driver's seat, means for detecting a decrease in driver's arousal level based on an estimation result of the means for estimating, and the detection And a warning means for notifying the driver of a decrease in the degree of arousal when the means for detecting a decrease in the degree of arousal of the driver.

  According to this, since the existing seating sensor or load sensor provided in the driver's seat can be used as the means for estimating the driving posture, it is possible to realize a wakefulness detection device that is inexpensive and has a simple configuration. it can.

  Further, the camera device that captures a driver's blink, and a blink detection unit that detects a decrease in the driver's arousal level according to the number of blinks per unit time photographed by the camera device. However, when the blink cannot be detected, the warning means informs the driver of the decrease in the arousal level based on the detection of the decrease in the arousal level by the detecting means. The arousal level can be detected by estimating the driving posture.

  According to the present invention, it is possible to realize a wakefulness detection device that is inexpensive and has a simple configuration.

(First Example)
A wakefulness detection device according to a first embodiment will be described with reference to FIGS. FIG. 1 is a diagram showing a driver's cab of a vehicle equipped with a wakefulness detection device of this embodiment.

  In the present embodiment, as shown in FIG. 1, the posture estimation unit 10 that estimates the driver's driving posture based on the weight distribution situation in a plurality of locations of the driver's seat 5, and the driver based on the estimation result of the posture estimation unit 10 An arousal level detection unit 11 that detects a decrease in the arousal level of the vehicle, and a warning notification unit 4 that notifies the driver of the decrease in the arousal level when the arousal level detection unit 11 detects a decrease in the arousal level of the driver. A wakefulness detection device provided. The posture estimation unit 10 and the arousal level detection unit 11 are configured as the arousal level detection unit 1.

  Next, the estimation principle of the driving posture of the driver in the posture estimation unit 10 of the arousal level detection unit 1 and the detection principle of the arousal level in the arousal level detection unit 11 will be described with reference to FIGS. FIG. 2 is a diagram illustrating an arrangement state of the load sensor 6 and the seating sensor 7 in the driver's seat 5. FIG. 3 is a diagram showing a load measurement area in the driver's seat 5. FIG. 4 is a flowchart showing a procedure for detecting a decrease in arousal level in the arousal level detection unit 1. FIG. 5 is a diagram for explaining the arousal level lowering pattern.

  As shown in FIG. 2, the driver's seat 5 is provided with a load sensor 6 at the backrest portion and a seating sensor 7 at the chair portion. As shown in FIG. 3, posture estimation unit 10 can individually measure loads for each of a plurality of regions # 1 to # 6 by means of load sensor 6 and seating sensor 7.

  As shown in FIG. 4, the posture estimation unit 10 acquires output values of the load sensor 6 and the seating sensor 7 (S1), and estimates the driver's posture (S2). For example, when a load is evenly applied to the regions # 1 to # 4 and almost no load is applied to the regions # 5 and # 6, the driver can estimate that his / her back is in a correct posture. Further, when the load is biased in the regions # 2 and # 4, the load is hardly applied to the regions # 1 and # 3, and no load is applied to the regions # 5 and # 6, the driver It can be estimated that the posture is leaning forward. In addition, when the load is biased in the regions # 1, # 3, # 5, and # 6 and the load is hardly applied to the regions # 2 and # 4, the driver is leaning against the backrest. Can be estimated. Further, when the load is biased to any one of the areas # 1 to # 4, the driver can estimate that the body is inclined.

  Further, after a predetermined time has elapsed (S3), posture estimation is performed again, and a posture change is calculated from the previous posture estimation result and the current posture estimation result (S4).

  As a result of the posture change calculation (S4), when the arousal level reduction pattern is detected (S5), the arousal level detection unit 11 outputs the arousal level reduction information (S6). When the warning notification unit 4 receives the arousal level decrease detection information from the arousal level detection unit 1, the warning notification unit 4 notifies the driver of the warning by the blinking of the lamp 2 and the ringing of the speaker 3.

  The predetermined time is, for example, several tens of seconds to several minutes, but the predetermined time is set to a short time of about several seconds (for example, 5 seconds). In the “wakefulness reduction pattern detection” in step S5, a plurality of cycles are used. The wakefulness reduction pattern may be detected by continuously observing the posture change over the entire area.

  Here, the arousal level reduction pattern will be described with reference to FIG. FIG. 5A is an example of a load movement frequent occurrence (“flicker”) pattern. As shown in FIG. 5 (a), a state in which the load is biased frequently occurs in any one of the regions # 1 to # 4, and as a result of continuously observing the posture change over a plurality of cycles, When it is biased toward different areas, it indicates a state where the driver's body is staggered, and the state of “stabilization” during driving can be determined as a reduction in the degree of arousal. In addition, it can recognize that it is driving | operation from the vehicle speed information from ECU8.

  FIG. 5B is an example of a “leaning” pattern. As shown in FIG. 5B, when the loads in the regions # 1 to # 4 decrease and the loads in the regions # 5 and # 6 increase, the driver is leaning against the backrest. The state of “leaning” during driving can be determined as a reduction in the degree of arousal.

  In addition to this, if the state of “bending forward” or “inclined” continues during driving, it may be a state of leaning on the handlebars and others due to falling asleep, which may reduce the arousal level. You can judge.

(Second embodiment)
A second embodiment will be described with reference to FIGS. FIG. 6 is a diagram showing a driver's cab of a vehicle equipped with the arousal level detection device of this embodiment. In this embodiment, as a complementary means for detecting a decrease in arousal level by blink detection, the detection of a decrease in arousal level by estimating the driver's posture in the first embodiment is adopted.

  In this embodiment, a camera device 9 that captures a driver's blink, a blink detection unit 20 that detects a decrease in the driver's arousal level according to the number of blinks per unit time captured by the camera device 9, and an awakening When the blink detection unit 20 cannot detect blinks, the warning notification unit 4 informs the driver of the arousal level based on the detection of a decrease in the arousal level by the posture estimation unit 10 and the arousal level detection unit 11. Notify the decline. The blink detection unit 20 and the wakefulness detection unit 21 are configured as the wakefulness detection unit 12.

  Next, the operation of the arousal level detection apparatus according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the warning notification unit 4 of this embodiment. As shown in FIG. 7, the warning notification unit 4 of the present embodiment normally employs the arousal level detection result based on the blink detection of the awakening level detection unit 12 (S10) and executes the warning notification.

  The arousal level detection unit 21 counts the number of blinks per unit time of the driver. At this time, if the number of blinks is abnormally small, it is determined that the blink is not normally detected. The main cause is that, as described above, even when the driver is wearing sunglasses or wearing transparent glasses, the outside scenery is reflected in the glasses lens. If the arousal level detection unit 21 determines that blinking is not normally detected, it outputs blink detection impossibility information to the warning notification unit 4.

  In parallel with the arousal level detection unit 12, the posture estimation unit 10 of the arousal level detection unit 1 estimates the driving posture of the driver, and the arousal level detection unit 11 detects the driver's arousal level based on the estimation result. is doing.

  When the warning notification unit 4 receives blink detection impossibility information from the arousal level detection unit 21 (S11), the warning notification unit 4 adopts the arousal level detection result based on the driving posture estimation of the arousal level detection unit 1 (S12).

  And the warning alerting | reporting part 4 will alert | report a warning to a driver | operator by blinking of the lamp | ramp 2 and the ringing of the speaker 3, if the alertness fall detection information from the alertness detection unit 1 or 12 is received (S13).

  According to the present invention, it is possible to realize a wakefulness detection device that is inexpensive and has a simple configuration. For example, in a wakefulness detection device based on blink detection, it is suitable for use as a supplementary wakefulness detection means when blink detection cannot be performed. Thereby, it can contribute to the avoidance of dozing driving.

The figure which shows the driver's cab of the vehicle carrying the arousal level detection apparatus of 1st Example. The figure which shows the arrangement | positioning state of the load sensor and seating sensor in a driver's seat. The figure which shows the load measurement area | region in a driver's seat. The flowchart which shows the fall detection procedure of the arousal level in the arousal level detection unit of 1st Example. The figure explaining a wakefulness fall pattern. The figure which shows the driver's cab of the vehicle carrying the arousal level detection apparatus of 2nd Example. The flowchart which shows operation | movement of the warning alerting | reporting part of 2nd Example.

Explanation of symbols

1, 12 Arousal level detection unit 2 Lamp 3 Speaker 4 Warning notification unit 5 Driver's seat 6 Load sensor 7 Seat sensor 8 ECU
9 Camera device 10 Posture estimation unit 11, 21 Arousal level detection unit 20 Blink detection unit # 1-# 6

Claims (2)

Means for estimating the driver's driving posture based on the weight distribution status in a plurality of locations of the driver's seat;
Means for detecting a decrease in the driver's arousal level based on the estimation result of the means for estimating;
An alertness detecting device comprising: warning means for notifying the driver of a decrease in the alertness level when the detecting means detects a decrease in the alertness level of the driver. A camera device that captures the blink of the driver;
Blink detection means for detecting a decrease in the driver's arousal level according to the number of blinks per unit time taken by the camera device;
The wakefulness detection device according to claim 1, wherein when the blink detection means cannot detect blinks, the warning means informs the driver of a decrease in wakefulness based on detection of a decrease in wakefulness by the detecting means.

Images