JPH09254742A - Awakening degree lowering detecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an awakening degree lowering detecting device which can accurately judge lowering of the awakening degree based on the moving speed of one's eye. SOLUTION: The moving speed of one's eye is computed based on the input image from a CCD camera, and a frequency distribution pattern showing correlation between the moving speed of one's eye computed for a fixed time and the frequency is made. By comparing a frequency distribution pattern reflecting individual difference of drivers made directly after beginning operation of a vehicle with a frequency distribution pattern in order made during operation of the vehicle, lowering of the awakening degree is judged (S15). Namely, it is judged whether the awakening degree lowers or not, by noticing that the peak of frequency appears on the low speed side, or the peak of frequency does not clearly appear and the moving speed of one's eye disperses, at lowering of the awakening degree. Thereafter, when the awakening degree is judged to lower, a warning such as buzzer is output for a fixed time in order to call a driver's attention (S16-19), and a counter for buzzer is reset (S20).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique of detecting a decrease in awakening of a driver while driving a vehicle and notifying the driver of danger.

[0002]

2. Description of the Related Art Conventionally, for the purpose of reducing a driver's awakening level while driving a vehicle and reducing traffic accidents due to drowsiness, the driver's awakening level can be reduced by measuring brain waves, operating the steering wheel, blinking, etc. Techniques for detecting drowsiness have been proposed.

[0003]

However, in the prior art, it cannot be said that the measured data surely shows a decrease in arousal level or a sign of drowsiness (hereinafter, referred to as "reduced arousal level"). In addition, it is troublesome and troublesome because the measurement sensor must be attached to the driver's body, and the fact is that it has not been put to practical use.

Therefore, the applicant of the present application filed an earlier application (Japanese Patent Application No.
No. 173221), the line-of-sight direction frequency distribution pattern is created by measuring the line-of-sight with a measuring means such as a CCD camera without mounting the measurement sensor on the driver's body. We devised a device for detecting decreased arousal level that detects decreased arousal level by comparing with the frequency distribution pattern in the direction.

However, in the method of detecting a decrease in arousal level based on the frequency distribution pattern in the line-of-sight direction, it is clear that it is difficult to capture an accurate decrease in arousal level due to individual differences in driver's senses and characteristics. It's coming. Therefore, in view of the above-mentioned problems of the prior application, the present invention focuses on the fact that the movement speed of the line of sight decreases or varies when the arousal level decreases, and based on the moving speed of the line of sight, it is possible to achieve high accuracy. It is an object of the present invention to provide a wakefulness lowering detection device that can determine a decrease in wakefulness.

[0006]

Therefore, according to the invention of claim 1, as shown in FIG. 1, a line-of-sight direction detecting means A for detecting the line-of-sight direction of the driver while driving the vehicle, and the detected line-of-sight direction. A moving speed calculating means B for calculating the moving speed of the line of sight based on the above; a pattern creating means C for creating a frequency distribution pattern of the moving speed of the line of sight within a predetermined time based on the calculated moving speed of the line of sight; The awakening degree reduction determining means D for determining whether or not the awakening degree has decreased by comparing the frequency distribution pattern sequentially created therein and the frequency distribution pattern immediately after the start of vehicle operation.

With this configuration, the line-of-sight direction detecting means detects the line-of-sight direction of the driver, the moving speed calculating means calculates the moving speed of the line of sight, and the pattern creating means creates a frequency distribution pattern within a predetermined time. . And
The frequency distribution pattern that is sequentially created by the awakening degree determination means is compared with the frequency distribution pattern that reflects individual differences in the driver's sensation and characteristics immediately after the start of vehicle operation, and it is determined whether or not the awakening degree is decreasing. It Therefore, even if the sensor or the like is not attached to the driver's body, the awakening degree reduction determination can be performed with high accuracy.

According to a second aspect of the present invention, there is provided a configuration including alarm generating means for issuing an alarm, wherein the alarm generating means issues an alarm when the awakening degree determining means determines that the awakening degree is decreasing. did. If you do this,
When it is determined that the awakening level has decreased, the warning is issued to the driver by the warning generating means.

According to a third aspect of the present invention, there is provided a traveling state detecting means for detecting a traveling state of the vehicle, wherein the moving speed calculating means is operable when the traveling state detecting means detects that the vehicle is traveling. The configuration is such that the moving speed of the line of sight is calculated. In this way, the moving speed of the line of sight is not calculated when the vehicle is stopped. In other words, when the vehicle is stopped, the frequency distribution pattern is not created based on the moving speed of the line of sight of the driver. It is possible to prevent the accuracy of the awakening degree deterioration determination from being deteriorated by the data when the vehicle is stopped in a direction different from the traveling state. Further, it is possible to prevent an unnecessary decrease in the awakening level from being made when the driver is taking a rest such as a nap while the vehicle is stopped.

According to a fourth aspect of the present invention, the awakening degree reduction determining means compares the created frequency distribution pattern with a frequency distribution pattern immediately after the start of vehicle operation, and whether the frequency peak appears on the low speed side, Alternatively, when the frequency peak is unclear and the moving speed of the line of sight varies, it is determined that the arousal level is decreased. By doing so, the awakening degree reduction determination is performed by focusing on the peak of the frequency appearing in the frequency distribution pattern.

According to a fifth aspect of the present invention, the frequency distribution pattern immediately after the start of vehicle operation is created when it is similar to a preset standard frequency distribution pattern. By doing so, when the reference frequency distribution pattern is different from the standard frequency distribution pattern, for example, when the driver's arousal level is already lowered when the frequency distribution pattern is created, such a state is generated. It is prevented that the frequency distribution pattern in is the reference pattern.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 shows a system configuration of an embodiment of the wakefulness decrease detecting device according to the present invention. A CCD camera 2 for inputting the movement of the driver's line of sight as an image is attached to the instrument panel 1 in the driver's seat, and the CCD camera 2 and the instrument panel 1 are attached.
An infrared light emitting diode 3 for irradiating the eyeball with infrared rays is attached to the eyeball in order to obtain a desired reflection image on the eyeball. That is, the infrared rays emitted from the infrared light emitting diode 3 are reflected by the retina and cornea of the driver, and the reflected light is C
It is input to the CD camera 2. Then, the image signal from the CCD camera 2 is input to the image processing device 4, where image processing for specifying the driver's line-of-sight direction at the line-of-sight position on the world coordinate system is performed. After that, the line-of-sight position signal of the driver obtained by the image processing device 4 is input to the control unit 5 incorporating a microcomputer.

The control unit 5 also includes
A vehicle speed signal VSP from a vehicle speed sensor 6 (running state detecting means) that detects the speed of the vehicle is input, and this vehicle speed signal V
Based on the SP and the driver's line-of-sight position signal, awakening degree reduction determination, which will be described later, is performed. Further, the warning light 7 and the buzzer 8 (alarm generating means) are provided in the control unit 5.
Drive control is performed by means of, and notification of various information in the awakening degree determination processing (mainly, notification of data abnormality) and warning when the awakening degree is reduced are configured to be issued.

The CCD camera 2, the infrared light emitting diode 3 and the image processing device 4 are included in the line-of-sight direction detecting means, and the control unit 5 includes the moving speed calculating means, the pattern forming means and the awakening degree determination. It has a function as a means. First, before explaining the content of the awakening degree reduction determination process, the principle of how the awakening degree reduction is detected will be described.

As shown in FIG. 5, the calculation of the moving speed v of the line of sight indicates that the position of the line of sight at a certain time t ₀ is (x ₀ , y ₀ ).
If the current value becomes (x ₁ , y ₁ ) at time t ₁ , it is calculated by the following equation.

[0016]

[Equation 1]

A frequency distribution pattern showing a correlation between the moving speed v of the line of sight and its frequency d while continuously calculating the moving speed v of the line of sight calculated in this way for a predetermined time, for example, 10 to 15 minutes. (Hereinafter referred to as “frequency distribution pattern”) is created. Here, looking at FIG. 6A showing an example of the frequency distribution pattern at the time of awakening, the peak of the frequency d with respect to the moving speed v clearly appears, and the peak appears at the approximate center of the moving speed v. ing. On the other hand, FIG. 6 showing an example of a frequency distribution pattern when the awakening level is lowered.
Looking at (b) and (c), although the peak of the frequency d clearly appears, whether the position of the peak appears on the low speed side (FIG. 6B), or the moving speed v The peak of the frequency d does not appear clearly, and the moving speed v of the line of sight varies (FIG. 6C).

Therefore, the frequency distribution pattern at the time of awakening is used as a reference pattern, and this reference pattern is compared with the frequency distribution pattern that is sequentially created during vehicle operation.
It is possible to detect a decrease in the driver's alertness at that time. Next, the content of such a wakefulness decrease detection process will be described based on the flowcharts shown in FIGS. 3 and 4. This processing is executed by the image processing device 4 and the control unit 5, and the processing is started at the same time when the vehicle is started.

In step 1 (abbreviated as S1 in the figure, the same applies hereinafter), various kinds of initialization in the awakening degree reduction determination processing are performed. Specifically, a frequency distribution pattern (hereinafter referred to as a “reference pattern”) that serves as a reference for resetting the counter, initializing the warning light 7 to be turned off, and determining awakening degree decrease.
Will be cleared. In step 2, the vehicle speed sensor 6
The vehicle speed signal VSP and the image signal from the CCD camera 2 are read.

In step 3, it is judged based on the vehicle speed signal VSP from the vehicle speed sensor 6 whether or not the vehicle is traveling, and if it is traveling, the procedure proceeds to step 4, otherwise it returns to step 2. . That is, this processing is performed in order to prevent the accuracy of the awakening degree deterioration determination from being lowered in view of the fact that the driver's line-of-sight direction is different from that when the vehicle is running when the vehicle is stopped. Further, it is possible to prevent an unnecessary determination of the awakening degree from being made when the driver stops the vehicle and takes a rest such as a nap.

In step 4, the line-of-sight position is determined based on the image signal from the CCD camera 2, and the moving speed v of the line-of-sight is calculated based on this line-of-sight position signal. This process corresponds to the moving speed calculation means. In step 5, a frequency distribution pattern (see FIGS. 6A to 6C) showing the correlation between the moving speed v of the line of sight and the frequency d thereof is created.

In step 6, the amount of moving speed data of the line of sight which is the basis for creating the frequency distribution pattern is sufficient, that is,
It is determined whether or not a frequency distribution pattern has been created based on a predetermined number of movement speed data, and if the data amount is sufficient, the process proceeds to step 7, and if the data amount is insufficient, the process returns to step 2 and the frequency distribution pattern is obtained. Continue creating the pattern. The processing of steps 5 and 6 corresponds to the pattern creating means.

In step 7, it is judged whether or not the reference pattern has not been created, that is, the created frequency distribution pattern is the first one, and if it is the first one, step 8
If it is not the first one, proceed to step 14. In step 8, a preset standard frequency distribution pattern (hereinafter referred to as "standard pattern") is read.

In step 9, step 2 to step 6
The reference frequency distribution pattern created in the processing of 1 is compared with the standard pattern. If the two patterns are similar, the process proceeds to step 10. If the two patterns are different, the process proceeds to step 12. That is, when the reference frequency distribution pattern is too far from the standard pattern, it is determined that the reference frequency distribution pattern has failed to be created, and the reference frequency distribution pattern is created again. In this process, for example, when the awakening level of the driver is already lowered when the frequency distribution pattern is created, consideration is made so that the frequency distribution pattern in such a state is not used as the reference pattern.

In step 10, since the reference frequency distribution pattern has been successfully created, this frequency distribution pattern is stored in the memory so as to be used as the reference pattern for determining the decrease in arousal level. It should be noted that this reference pattern reflects individual differences in driver's sense and characteristics. Step 1
In 1, the warning lamp 7 indicating the data abnormality is turned off, and the process returns to step 2.

On the other hand, in step 9, the reference frequency distribution pattern is different from the standard pattern, that is,
In step 12 when it is determined that the creation of the reference frequency distribution pattern has failed, the warning light 7 is turned on to notify the driver that the creation of the reference pattern has failed. In step 13, in order to recreate the reference pattern from the beginning, all the data of the current frequency distribution pattern is cleared, and the process returns to step 2.

When it is determined in step 7 that the reference pattern has been created, in step 14, the reference pattern is read from the memory. In step 15, the frequency distribution pattern is compared with the reference pattern, and when the peak of the frequency distribution pattern appears on the lower speed side than the reference pattern, or when the peak does not appear clearly and the moving speed of the line of sight. If there is variation in v, it is determined that the driver's arousal level has decreased and step 16
If it is determined that the awakening level has not decreased, the process returns to step 2.

The processing of steps 14 and 15 corresponds to the awakening degree reduction determining means. In step 16, the buzzer 8 as an alarm is turned on to call the driver's attention. In step 17, the counter is incremented. In step 18, it is determined whether or not the counter has reached a predetermined value. When the counter has reached the predetermined value, the process proceeds to step 19, and when it has not reached the predetermined value, the process returns to step 17.

In step 19, the buzzer 8 is turned off. That is, in the processing of steps 16 to 19, the buzzer 8 is sounded for a predetermined time to alert the driver to wake him up from the state where the awakening level at which he is likely to start falling asleep has decreased. In step 20, the counter for buzzer 8 is reset, and the process returns to step 2.

According to the configuration described above, the infrared light emitted from the infrared light emitting diode 3 is reflected by the eyeball of the driver and input to the CCD camera 2. Based on this image signal, the image processing device 4 causes the image processing device 4 to display in world coordinates. Specify the line-of-sight position. The moving speed of the line of sight is calculated from the position of the line of sight, and based on the moving speed of the line of sight calculated within a predetermined time, a frequency distribution pattern showing a correlation between the moving speed of the line of sight and its frequency is created. Then, by comparing the frequency distribution pattern that is sequentially created while the vehicle is driving with the frequency distribution pattern that is created immediately after the start of the vehicle driving, it is possible to improve the awakening degree reduction determination regardless of the individual difference in the driver's sense and characteristics. Can be done with precision. That is, it is not necessary to consider individual differences among drivers because the awakening degree reduction determination is performed by comparing the frequency distribution pattern immediately after the start of vehicle driving of each driver with the frequency distribution pattern that is sequentially created during vehicle driving. .

Further, when it is determined that the awakening level is lowered, the alarm is issued to the driver by the alarm generating means. For example, when the driver is about to start dozing, this alarm will wake up, It is possible to avoid an accident such as a rear-end collision caused by a decrease in arousal level or dozing. Further, since it is not necessary to attach a sensor or the like to the driver's body, the driver's fatigue can be prevented and the awakening degree lowering detection device can be put into practical use.

[0032]

As described above, according to the first aspect of the present invention, the awakening degree lowering judgment is made by comparing the frequency distribution pattern immediately after the start of the vehicle driving with the frequency distribution pattern sequentially created during the vehicle driving. Since it is performed, it is not necessary to consider individual differences in driver's senses and characteristics, and it is possible to perform the awakening degree reduction determination with high accuracy. Further, unlike the conventional case, it is not necessary to attach a sensor or the like to the body of the driver, so that fatigue of the driver can be suppressed as much as possible.

According to the second aspect of the present invention, since the driver is alerted when it is determined that the awakening level is low, it is possible to avoid an accident such as a rear-end collision caused by a low awakening level or dozing. it can. According to the invention described in claim 3, since the moving speed of the line of sight is not calculated while the vehicle is stopped, it is possible to reduce the accuracy of the awakening degree determination due to the data when the vehicle is in a different line of sight from the running state. It can be prevented. Further, it is possible to prevent an unnecessary determination of the awakening degree from being made when the driver is taking a rest such as a nap while the vehicle is stopped.

According to the fourth aspect of the present invention, it is possible to determine the decrease in arousal level by a simple comparison method, paying attention to the frequency peaks appearing in the frequency distribution pattern. Claim 5
According to the described invention, when the reference frequency distribution pattern is different from the standard frequency distribution pattern, for example,
If the driver's arousal level is already reduced when the frequency distribution pattern is created, the frequency distribution pattern in such a state is prevented from becoming the reference pattern, and the arousal level reduction detection accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a diagram for responding to a claim according to claim 1 of the present invention.

FIG. 2 is a system diagram showing an embodiment of a wakefulness decrease detecting device according to the present invention.

FIG. 3 is a flowchart showing the awakening degree reduction determination process of the above.

FIG. 4 is a flowchart showing the same awakening degree reduction determination process as above.

FIG. 5 is a diagram showing a method of calculating the moving speed of the line of sight.

FIG. 6 shows an example of a frequency distribution pattern, (a) shows a pattern when awakening, and (b) and (c) shows a pattern when awakening level is lowered.

[Explanation of symbols]

 2 CCD camera 3 Infrared light emitting diode 4 Image processing device 5 Control unit 6 Vehicle speed sensor 8 Buzzer

Claims (5)

[Claims] 1. A line-of-sight direction detecting means for detecting a line-of-sight direction of a driver who is driving a vehicle, a moving-speed calculating means for calculating a moving speed of the line-of-sight based on the detected line-of-sight direction, and a calculated moving speed of the line-of-sight. A pattern creation means that creates a frequency distribution pattern of the moving speed of the line of sight within a predetermined time based on the above, and a frequency distribution pattern that is sequentially created while the vehicle is driving and a frequency distribution pattern immediately after the start of the vehicle driving are compared to determine the arousal level. And a decrease in arousal level in a vehicle, which is configured to include an awakening level decrease determining unit that determines whether or not the level has decreased. 2. An alarm issuing means for issuing an alarm, wherein the alarm issuing means issues an alarm when the awakening degree decrease determining means determines that the awakening degree is decreasing. An awakening degree lowering detection device in the vehicle described. 3. A running state detecting means for detecting a running state of the vehicle, wherein the moving speed calculating means detects the moving speed of the line of sight when the running state detecting means detects that the vehicle is running. The awakening degree reduction detection device for a vehicle according to claim 1 or 2, wherein the detection is performed. 4. The awakening degree lowering determination means compares the created frequency distribution pattern with a frequency distribution pattern immediately after the start of vehicle operation, and the frequency peak appears on the low speed side, or the frequency peak appears. The awakening degree lowering detection device for a vehicle according to claim 1, wherein it is determined that the awakening degree is lowered when it is unclear and there is variation in the moving speed of the line of sight. . 5. The frequency distribution pattern immediately after the start of operation of the vehicle is created when the frequency distribution pattern is similar to a preset standard frequency distribution pattern.
A device for detecting a decrease in awakening degree in a vehicle according to any one of 1.