JPH10250404A - Falling asleep at the wheel prevention device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent driver's falling asleep at the wheel by changing over a detected living body condition and comparing it with falling asleep at the wheel judgement sensitivity by a falling asleep at the wheel judgement means when falling asleep at the wheel judgement sensitivity is changed over to high sensitivity based on the operation of a head lamp switch. SOLUTION: An output detected by an illuminance sensor 20b is input into a microcomputer 30. The detected illuminance is compared with a predetermined reference level for judgement, and if the illuminance is high, falling asleep at the wheel judgement sensitivity is changed over to predetermined high sensitivity. It the illuminance is low, an output of a head lamp switch 20a is input. If the switch 20a is turned on, it means the reduction of illuminance of a running environment which requires the lighting of a head lamp, and falling asleep at the wheel judgement sensitivity is changed over to predetermined high sensitivity. If the switch 20a is off, it is changed over to usual sensitivity. When the change-over processing is done, an output detected by a pulse sensor 10 is input as pulse data and is compared with falling asleep at the wheel judgment sensitivity for judgement. If the sensitivity is low, a driver falls asleep during driving. Consequently, an alarm processing is done and an alarm device 40 gives an alarm to prevent driver's falling asleep at the wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drowsy driving prevention device for preventing a driver driving a vehicle from falling asleep.

[0002]

2. Description of the Related Art Conventionally, when a vehicle is driven at night or in a long tunnel such as the Chuo Expressway Enayama Tunnel, the driver tends to fall asleep due to the monotonous feeling. In response to this, there has been proposed a drowsiness driving detection device that detects and prevents drowsiness driving based on the operation frequency of various operation mechanisms such as a vehicle steering mechanism (Japanese Patent Laid-Open No. 5-31).
No. 9135).

[0003]

However, in the case of the above-mentioned dozing driving detecting device, the operation of various operating mechanisms is performed in a variety of manners in accordance with a running environment that changes in a variety of ways such as a road condition of a vehicle and weather. . For this reason, even if the operation frequency of various operation mechanisms is detected, there is a problem that the detection accuracy required for preventing drowsy driving cannot be obtained.

On the other hand, the present inventors have made various studies on the cause of the driver's falling asleep, taking the driving state of a vehicle in the Chuo Expressway Enayama tunnel as an example.
Due to the monotonous feeling of driving, the decrease in illuminance around the vehicle
It was found that it was easy to induce drowsy driving. In addition, since the driving environment and the driver's biological information that cause a decrease in the illuminance around the vehicle have a close relationship with the traveling position of the vehicle, grasping the traveling position makes it possible for the driver to fall asleep. I also know that I can know.

Accordingly, the present invention provides a vehicle drowsy driving prevention device for preventing a driver from falling asleep due to monotonous driving in a low illuminance environment such as a long tunnel or at night based on the above viewpoints. The purpose is to do.

[0006]

To achieve the above object, according to the first aspect of the present invention, the drowsiness driving determination sensitivity switching means switches the drowsiness driving determination sensitivity higher based on the operation of the headlight switch. Then, the drowsy driving determination unit switches the biological state detected by the biological condition detection unit and compares the detected biological state with the drowsy driving determination sensitivity to determine whether or not the driver is dozing.

Thus, when the drowsy driving determining means determines that the driver is dozing under the operation of the headlight switch, the notifying means notifies the driver of dozing driving. As a result, it is possible to surely prevent a drowsy driving that tends to occur with driving at night or in a long tunnel where a headlight is turned on without employing a special sensor. According to the second aspect of the present invention, the driving environment determining means determines whether or not the illuminance detected by the illuminance sensor is in a low illuminance driving environment such as a night or a long tunnel that causes the driver to fall asleep. . When the driving environment determining unit determines that the driving environment is the low illuminance driving environment, the dozing driving determination sensitivity switching unit switches the dozing driving determining sensitivity to a high level.

Along with this, the drowsy driving determination means switches the detected biological state and compares it with the drowsiness driving determination sensitivity to determine the presence or absence of the driver's drowsiness driving. According to this, although the point that an illuminance sensor is employed in place of the headlight switch is different, it is possible to achieve the same drowsy driving prevention as in the first aspect. If the vehicle is equipped with an automatic light control device that automatically turns on and off the headlights, the automatic light control device may function as an illuminance sensor.

According to the third and fourth aspects of the present invention, the traveling environment determining means determines that the traveling position detected by the traveling position detecting means causes the driver to fall asleep at night or in a low-illuminance traveling environment such as a long tunnel. Is determined. When the traveling environment determination means determines that the vehicle is in the low-illuminance traveling environment, the drowsiness driving determination sensitivity switching means switches the drowsiness driving determination sensitivity to a higher value.

[0010] Accordingly, the drowsy driving judging means judges the presence or absence of the driver's dozing driving by switching the living body state detected by the living body state detecting means and comparing it with the dozing driving judgment sensitivity. Thus, without using the headlight switch or the illuminance detection means, even if the travel position detection means is used,
Since the detected traveling position can be associated with a low-illuminance traveling environment such as a nighttime or a long tunnel, the same operation and effect as those of the first and second aspects can be achieved.

If the vehicle employs a navigator system, the traveling position detecting means can be eliminated by utilizing the position information of the navigator system. This can also be achieved by using the output of a receiving circuit for road-to-vehicle communication such as a beacon. Here, according to the invention described in claim 4, the traveling information notifying unit reports the traveling information of the vehicle in the low illuminance traveling environment as the dozing driving prevention information.

As a result, it is possible to further improve the prevention of falling asleep in a low-illuminance driving environment. According to the fifth aspect of the present invention, when the vehicle is in a low-illuminance driving environment such as a night or a long tunnel where the driver falls asleep, the drowsiness driving determination unit may detect the biological state detected by the biological state detection unit. Is compared with the dozing driving determination sensitivity to determine whether or not the driver is dozing.

According to this, the same operation and effect as the first to third aspects of the invention can be achieved.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing a first embodiment of a vehicle drowsy driving prevention device according to the present invention.

The drowsy driving prevention device comprises a pulse sensor 1
0, a microcomputer 30 connected to the headlight switch 20a and the illuminance sensor 20bb, and an alarm device 40 connected to the microcomputer 30. The pulse sensor 10 detects the driver's pulse state. The headlight switch 20a is turned on or off when turning on or off the headlight of the vehicle according to the driver's intention. The illuminance sensor 20b detects the illuminance around the vehicle.

The microcomputer 30 executes a computer program according to the flowchart shown in FIG. 2. During this execution, the microcomputer 30 performs a drowsiness driving determination process based on the outputs of the pulse sensor 10, the headlight switch 20a and the illuminance sensor 20bb. Do the processing. In the first embodiment configured as described above, when the microcomputer 30 starts executing the computer program according to the flowchart of FIG. 2, in step 100, the detection output of the illuminance sensor 20ba is input to the microcomputer 30 and is converted into a digital signal. Is set as the detected illuminance.

Next, at step 110, the detected illuminance is compared with a predetermined reference level TH. The reference illuminance TH corresponds to a predetermined illuminance on the characteristic data L representing a temporal change in the detected illuminance, as shown in FIG. Here, the predetermined illuminance corresponds to an upper limit value that easily induces a drowsy driving to the driver under a monotonous driving of the driver while the vehicle is traveling in a long tunnel or at night.

If the detected illuminance is higher than the reference illuminance TH, the determination in step 110 is YES, and in step 121, the drowsy driving determination sensitivity S
Is switched to the predetermined high sensitivity Sh (see FIG. 3B). On the other hand, if the determination in step 110 is NO, in step 111, the headlight switch 20
The output of “a” is input to the microcomputer 30.

In step 120, if the headlight switch 20a is turned on, the headlight is turned on. This means that the illuminance of the traveling environment of the vehicle is reduced so that the headlight needs to be turned on.
Therefore, in step 121, the drowsiness driving determination sensitivity S is switched to the predetermined high sensitivity Sh (see FIG. 3B) as described above.

On the other hand, if the determination in step 120 is NO
In step 122, the drowsiness driving determination sensitivity S is switched to the normal sensitivity So (see FIG. 3B). Note that the normal sensitivity So is lower than the predetermined high sensitivity Sh. As described above, when the switching processing in any of steps 121 and 122 is performed, step 12
At 3, the detection output of the pulse sensor 10 is input to the microcomputer 30 and converted into digital data as pulse data.

In step 130, the value of the pulse data is compared with the drowsy driving determination sensitivity S = So or Sh. If the value of the pulse data is lower than the drowsiness driving determination sensitivity S = So or Sh, the driving in the drowsiness is determined, so that the determination in step 130 is YES,
At step 131, an alarm process for preventing a drowsy driving is performed. Accordingly, the alarm device 40 issues an alarm.

Therefore, even when the vehicle is in a long tunnel or in a night driving state, the operation of the driver is monotonous and the illuminance around the driver is low, it is possible to appropriately prevent the driver from falling asleep. In the first embodiment, an example in which the dozing driving determination sensitivity S is switched to two levels has been described. Instead, for example, as shown in FIG. 4, the dozing driving determination sensitivity S is switched to three levels. In this way, the determination of the drowsy driving prevention may be performed more finely.

Here, the operation of the headlight switch 20a is normally performed in three steps of turning off, turning on the small lamp, and turning on the headlight. In this order, the illuminance is bright and dim. It is conceivable to change to values corresponding to the state and the dark state. Therefore, based on these, it is assumed that the detected illuminance is high and bright when both the headlight and the small lamp are turned off. For this reason, the drowsy driving determination sensitivity S
Lower.

When only the small lamp is turned on, the illuminance is medium and dim. Accordingly, the drowsy driving determination sensitivity S is set to a medium value. When the headlight is turned on, the illuminance is low and dark. For this reason,
The drowsiness driving determination sensitivity S is increased. In the first embodiment, the headlight switch 20a and the illuminance sensor 20b
Are used to switch the drowsiness driving determination sensitivity S. However, the present invention is not limited to this.
Even if one of the outputs of both the a and the illuminance sensor 20b is used for switching the dozing driving determination sensitivity S, the same operation and effect as in the first embodiment can be achieved. (Second Embodiment) FIG. 5 shows a second embodiment of the vehicle drowsy driving prevention device according to the present invention.

This drowsy driving prevention device has the pulse sensor 10 described in the first embodiment. The drowsy driving prevention device includes a position sensor 50, a vehicle speed sensor 60, and a memory 70 instead of the headlight switch 20a and the illuminance sensor 20bb described in the first embodiment. The position sensor 50 is a so-called GPS, and detects the traveling position of the vehicle as the position data A. The vehicle speed sensor 60 detects the vehicle speed of the vehicle and outputs a vehicle speed signal at a frequency proportional to the detected vehicle speed.

The memory 70 stores traveling geographic information of the vehicle in advance, and outputs the traveling geographic information including the traveling position of the vehicle to the microcomputer 80. The microcomputer 80 executes the computer program according to the flowchart shown in FIG. 6, and during this execution, the buzzer circuit 90a and the display device 90b are controlled based on the outputs of the pulse sensor 10, the position sensor 50, the vehicle speed sensor 60, and the memory 70. Various processes for the driving process are performed.

In the second embodiment configured as described above, if the microcomputer 80 starts executing the computer program according to the flowchart of FIG. 6, in step 200, the position information from the memory 70 includes the running position of the vehicle. The information is input to the microcomputer 80 as traveling geographic information. For example, if the vehicle is traveling near the Chuo Expressway Enayama tunnel, the entrance data X1 and the exit data X2 of the Chuo Expressway Enayama tunnel
Is included in the traveling geographic information.

Next, at step 210, the detected position data A of the position sensor 50 is
Input to 0. Thereafter, if the detected position data A matches the entrance data X1, the determination at step 220 is Y
ES. Accordingly, the current time t is set to t = 0.

Then, in step 222, the current geographic information is processed as display data. Along with this,
The display device 90b displays the current geographic information based on the display data. Then, in step 223, the vehicle speed V is calculated based on the vehicle speed pulse of the vehicle speed sensor 60. Subsequently, in step 224, a difference between the entrance data X1 and the exit data X2 is calculated, and a product of the vehicle speed V and the current time t is calculated. Then, a passing distance {(X1−X2) −V · t} from the entrance of the vehicle in the Chuo Expressway Enayama tunnel is calculated and processed as display data.

Along with this, the display device 90b displays the passing distance as the drowsy driving prevention display information based on the display data. This makes it possible to prevent the driver from falling asleep. Note that this display shows a change in color (red →
(Orange → yellow) or a change in brightness.

After the display, in step 225, the dozing driving determination sensitivity S is switched from the dozing driving determining sensitivity So described in the first embodiment to the dozing driving determining sensitivity Sh. Then, in step 230, the output of the pulse sensor 10 is compared and determined with the dozing driving determination sensitivity Sh. Accordingly, if a determination similar to the determination of YES in step 130 described in the first embodiment is made, a process similar to the process in step 131 is performed in step 231. Accordingly, the buzzer circuit 90a emits an alarm sound. This makes it possible to prevent the driver from falling asleep in the Enasan tunnel at the Chuo Expressway.

After the vehicle has traveled, when the vehicle reaches the exit of the Chuo Expressway Enayama Tunnel, a determination of YES is made in step 240 based on the fact that the position data A matches the exit data X2. For this reason, the erasure processing of the geographic information is performed in step 241, and in the next step 242, the switching dozing driving determination sensitivity in step 230 returns to the value before the switching.

Each step in the flowcharts of the above embodiments may be realized by a hardware logic configuration as a function executing means. Further, in implementing the present invention, a value corresponding to the difference between the predetermined high sensitivity Sh and the normal sensitivity So is obtained from the detection output of the pulse sensor 10 without switching the dozing driving determination sensitivity as described in each of the above embodiments. The value obtained by subtracting the value is a predetermined high sensitivity S
Even if h is used instead of h, the same drowsy driving prevention as in the above embodiments can be achieved.

In practicing the present invention, a sensor for detecting skin potential, blinking, brain waves, etc. may be employed instead of the pulse sensor 10. Further, in practicing the present invention, the notification may be made by the output of the vehicle seat vibration device, the scent controller, the air conditioning control device, or the like, instead of the notification by the buzzer circuit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the microcomputer of FIG.

3A is a graph showing a relationship between a detected illuminance characteristic of the illuminance sensor of FIG. 1 and a reference illuminance TH, and FIG.
6 is a graph showing switching characteristics of a drowsiness driving determination sensitivity S.

FIG. 4 is a table showing a relationship between turning on / off of a headlight and a small lamp of a vehicle, and illuminance and a drowsiness driving determination sensitivity.

FIG. 5 is a block diagram showing a second embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the microcomputer of FIG.

[Explanation of symbols]

10 pulse sensor, 20a headlight switch, 20b
Illuminance sensor, 30, 80... Microcomputer, 40
... alarm device, 50 ... GPS, 60 ... vehicle speed sensor, 70 ...
Memory, 90a: buzzer circuit, 90b: display device.

Continued on the front page (72) Inventor Moto Oda 14 Iwatani Shimowa Kakucho, Nishio City, Aichi Prefecture Inside Japan Automotive Parts Research Institute Co., Ltd. Inside the Automotive Parts Research Laboratory (72) Inventor Tetsuya Mizuno 1-1-1 Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (5)

[Claims] 1. A living body state detecting means (10) for detecting a living body state of a driver of a vehicle equipped with a headlight which is turned on by operating a headlight switch (20a); A drowsiness driving determining means (130) for determining the presence or absence of a drowsiness driving of the driver by comparing with the sensitivity; and an informing means (131, 131) for informing the drowsiness driving of the driver based on the determination of the drowsiness driving by the drowsy driving determination means.
40) a drowsy driving prevention device comprising: a drowsiness driving determination sensitivity switching unit (121) that switches the drowsiness driving determination sensitivity to a high level based on the operation of the headlight switch; A drowsiness prevention device for a vehicle, which determines whether or not the driver has fallen asleep by comparing the detected biological state with the switching drowsiness determination sensitivity under operation of an illumination switch. A living body condition detecting means for detecting a living condition of a driver of the vehicle; and a drowsiness driving determination for judging presence or absence of the driver's drowsiness by comparing the detected biological condition with a drowsiness driving determination sensitivity. Means (130), and notification means (131, notifying the driver of the drowsiness driving based on the determination of the drowsiness driving by the drowsiness driving determination means.
40) a drowsy driving prevention device comprising: (a) an illuminance detection means for detecting illuminance around the vehicle;
A driving environment determining unit (110) for determining whether the detected illuminance is in a low illuminance driving environment such as a night or a long tunnel that causes the driver to fall asleep, and A drowsiness driving determination sensitivity switching means (121) for switching the drowsiness driving determination sensitivity to a higher value when the environment is determined to be high, wherein the drowsiness driving determination means is the low-illuminance driving environment by the driving environment determination means. A drowsiness prevention device for a vehicle, wherein the presence or absence of the driver's drowsiness driving is determined by comparing the detected biological state with the switching drowsiness driving determination sensitivity. A living body condition detecting means for detecting a living body condition of a driver of the vehicle; a drowsiness driving determination for comparing presence / absence of the driver's dozing operation by comparing the detected biological condition with a drowsy driving determination sensitivity; A drowsiness driving preventing device comprising: a drowsiness driving notifying unit for notifying the driver of drowsiness driving based on the determination of the drowsiness driving by the drowsiness driving determination unit; Travel position detecting means (50) for detecting
Traveling environment determining means (220 to 223) for determining whether or not the detected traveling position is in a low-illuminance traveling environment such as at night or a long tunnel at which the driver falls asleep, and A drowsiness driving determination sensitivity switching unit (225) that switches the drowsiness driving determination sensitivity to a high level when it is determined that the vehicle is in the low-illuminance driving environment; A drowsing driving prevention device for a vehicle, which determines whether or not the driver is drowsy by comparing the detected biological condition with the switching drowsy driving determination sensitivity based on the determination that 4. The drowsy driving prevention device for a vehicle according to claim 3, further comprising driving information notifying means (90b) for notifying the driving information of the vehicle in the low-illuminance driving environment as drowsy driving prevention information. 5. A drowsiness driving detecting means (10) for detecting a dwelling state of a driver of a vehicle, and a drowsiness driving determination for comparing presence / absence of the drowsiness driving of the driver by comparing the detected dwelling state with a drowsiness driving determination sensitivity. Means (230), and a notifying means (231, notifying the driver of the drowsiness driving based on the determination of the drowsiness driving by the drowsiness driving determination means.
90a), wherein the dozing driving judging means performs the judging when the vehicle is in a low light driving environment such as at night or a long tunnel where the driver causes the driver to drowsy. Drowsy driving prevention device for vehicles.