JP3092283B2 - Drowsy driving detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a drowsy driving, and more particularly to an apparatus for detecting a drowsy driving from a change in the position of a vehicle.

[0002]

2. Description of the Related Art A dozing driving detecting device for detecting a dozing state of a driver has been developed for the purpose of ensuring safety when driving on a highway or the like.

[0003] Such a drowsy driving detection device employs a configuration in which the steering angle of a vehicle is usually monitored and a decrease in the consciousness level of the driver, that is, a drowsiness is determined from the change in the steering angle.

For example, in a vehicle alarm system disclosed in Japanese Patent Application Laid-Open No. 60-15230, a steering change is monitored based on a vehicle speed detection value and a steering angle detection value, and the steering change pattern exceeds a reference steering change pattern. A configuration is shown in which a warning for awakening is issued when it is determined that the alarm has occurred.

[0005]

However, in such a configuration in which a drowsy driving is detected from a change in the steering, even if the driver performs a normal steering in a awake state on a curved lane, the standard steering pattern is exceeded. There is a high possibility that it is determined that a drowsy driving has occurred, so that there is a problem that the vehicle effectively operates basically only on a straight road.

[0006] Further, the change in the steering angle largely depends on the individual differences of the drivers, and there are cases where the driver tends to take a large steering angle even during normal driving. There was a problem that lacked versatility that could accommodate all drivers.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to detect a drowsy driving on a running road regardless of a driver's individual difference. Is to provide.

[0008]

To achieve the above object, a drowsy driving detecting device according to claim 1 comprises: a position detecting means 1 for continuously detecting a vehicle position on a road as shown in FIG. Reference value calculating means 2 for calculating a reference value of the vehicle position during normal operation as a function of vehicle speed, first comparing means 3 for comparing the vehicle position after a predetermined time has elapsed from the start of traveling with the reference value, It has a measuring means 4 for measuring a return time when the vehicle position falls below the reference value again when the vehicle position exceeds the reference value, and a second comparing means 5 for comparing the return time with a predetermined value. It is characterized by the following.

In order to achieve the above object, a drowsy driving detecting device according to a second aspect of the present invention is a position detecting means for continuously detecting a vehicle position on a road as shown in FIG.
A steering angle detecting means 6 for detecting a steering angle of the vehicle, a phase difference calculating means 7 for detecting a time delay of a change in the steering angle with respect to a change in the vehicle position, and a reference time for the time delay during normal operation. Is calculated as a function of the vehicle speed, first reference means 9 for comparing the time delay after a predetermined time has elapsed from the start of traveling with the reference time, and the time delay exceeds the reference time. Measuring means 1 for measuring a return time in which the time delay is again less than or equal to the reference time
0, and a second comparing means 11 for comparing the return time with a predetermined value.

[0010]

According to the first aspect of the present invention, the drowsy driving detection device detects a vehicle position such as a lateral displacement amount and a yaw angle with respect to a road direction (lane mark), not a steering angle of the vehicle, and detects the vehicle position during normal driving. In this case, the drowsy driving is detected by monitoring how long it returns to the reference value when the reference value is exceeded. As is well known, a driver always drives by repeating three steps of recognition, judgment, and operation. However, when the driver's consciousness level decreases, the processing speed in each of the above-described steps decreases. Therefore, for example, when an abnormal lateral displacement of a vehicle is recognized, and it is attempted to correct it, it cannot be corrected as quickly as in normal driving, and the time for performing the correction substantially in proportion to the decrease in the consciousness level is long. It is becoming. In addition, there is a delay in recognition of the amount of lateral displacement and the like as compared with the normal operation.

Therefore, this correction is performed, and the time to return to the reference value, that is, the return time is measured, and the drowsy driving can be detected by the increase of the return time.

Unlike the steering angle, the lateral displacement and the yaw angle with respect to the running direction (lane mark) are physical quantities indicating the deviation from the normal position of the vehicle regardless of the running route. It is effective for

Since the reference value is calculated based on the driver's normal driving, it is possible to make a determination according to the driver.

On the other hand, in the dozing driving detecting device according to the second aspect, instead of comparing the vehicle position with the reference value, the time difference between the vehicle position change and the steering angle change, that is, the phase difference is compared with the reference time, If the time exceeds the reference time, the drowsy driving is detected based on how long the time is corrected to be below the reference time again.

As described above, the driver always performs recognition, judgment, and operation. However, if the driver's consciousness level decreases, the time from recognition to operation becomes longer, and therefore, changes in lateral displacement and the like are recognized. However, a change in the steering angle as a result of the operation based on the change also indicates a delayed change (that is, the phase difference increases).

Accordingly, the drowsy driving can be similarly detected by detecting the increase in the phase difference and monitoring the time until the phase difference returns to the normal phase difference again.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a drowsy driving detection device according to the present invention will be described below with reference to the drawings.

First Embodiment FIG. 3 is a block diagram showing the configuration of this embodiment, and FIG. 5 is a flowchart showing the processing of this embodiment. An image sensor 20 including a CCD camera and an image processor as a position detecting means is attached to the upper part of the driver's seat behind the rearview mirror. The image sensor 20 obtains a lateral displacement x, a forward displacement y,
The yaw angle φ with respect to the traveling direction (lane mark) is detected. The detection method can be determined from a known method, for example, from the position and inclination of a white line in an image. Then, the lateral displacement x, the forward displacement y, and the yaw angle φ with respect to the traveling road direction (lane mark) are input to a basic operation pattern analysis unit 22 a including a CPU in the microcomputer 22. On the other hand, the vehicle speed v at this time is detected by the vehicle speed sensor 24 and input to the basic driving pattern analysis unit 22a (S10).
1). FIG. 4 illustrates the relationship between the lateral displacement x, the forward displacement y, and the yaw angle φ.

It is considered that normal operation is performed for 5 minutes after the start of traveling, and the basic operation pattern analysis unit 22a
In, the reference value of the lateral displacement x, the forward displacement y, or the yaw angle φ is calculated. As the reference value, the maximum value or the average value of the data for 5 minutes can be used, but these data change according to the vehicle speed v, and thus need to be set for each vehicle speed (S103). In this embodiment, the maximum value for 5 minutes is set as the reference value. Then, the reference value for each vehicle speed for 5 minutes after the start of traveling is stored in the memory 22b in the microcomputer 22 as a basic operation map.

After a lapse of 5 minutes, there is a high possibility that a drowsy driving will occur, so that these reference values and the current lateral displacement x, forward displacement y detected by the image sensor 20, or yaw angle φ are calculated. The magnitude comparison is performed by the comparator 22c under the same vehicle speed condition (S104). Specifically, a reference value at the vehicle speed is read from the memory 22b in accordance with the vehicle speed from the vehicle speed sensor 24, and the current lateral displacement x, forward displacement y, and traveling direction (lane mark) input to the comparator 22c. ) Is compared with the yaw angle φ.

Here, when the driver's consciousness starts to decrease, steering different from that during normal driving is performed, so that the reference value may be exceeded even under the same vehicle speed condition. For example, when focusing on the lateral displacement amount, when the driver's consciousness level is sufficiently high, the vehicle travels substantially in the center of the traveling lane, so the lateral displacement amount x is small, but when the consciousness level starts to decrease, appropriate steering along the traveling lane is performed. Is not performed, and the lateral displacement x also increases. In this case, the timer 22d starts time measurement, and measures the time until the driver recognizes the abnormal position and returns to the reference value again (S105). Specifically, when the value exceeds the reference value, the CPU sends the set signal to the timer 22d.
To start the operation, and when it returns to the reference value again, a reset signal is supplied to the timer 22d for resetting. Then, the reset time is supplied to the comparator 22c. As described above, when a drowsy driving occurs, the abnormal lateral displacement x and the forward displacement y are recognized, and the time required to return the values to the original values significantly increases. Therefore,
This return time is compared with a predetermined value (for example, 0.5 seconds at 60 km / h) stored in the memory 22b in advance by the comparator 22c (S106). When it is determined that the alarm has occurred, the alarm 28 is activated (S107). The predetermined value may be set by the driver himself from a setting switch provided near the driver's seat.

As described above, in the present embodiment, attention is paid to the time required to deviate from the reference values such as the lateral displacement and the forward displacement and to the return, and the return time increases as the driver's consciousness level decreases. This makes it possible to detect the drowsy driving without fail irrespective of the runway and according to the individual difference of the driver.

Second Embodiment FIG. 6 is a block diagram showing the configuration of a second embodiment of the present invention, and FIG. 7 is a flowchart showing the processing. The difference from the first embodiment is that the image sensor 2
0, in addition to the vehicle speed sensor 24, a steering angle sensor 30 for detecting a steering angle of the vehicle is further provided, and the occurrence of a drowsy driving is detected based on the relationship between the vehicle position and the steering angle. The image sensor 20 detects the lateral displacement x, the forward displacement y, and the yaw angle φ with respect to the traveling road direction (lane mark), and these data are input to the basic driving pattern analysis unit 22a. The vehicle speed v detected by the vehicle speed sensor 24 and the steering angle of the vehicle detected by the steering angle sensor 30 are also input to the basic operation pattern analysis unit 22a.

Until five minutes have passed since the start of traveling, the first
It is considered that the normal operation is performed as in the embodiment, and the basic operation pattern analysis unit 22a determines the lateral displacement x and the steering angle θ.
, Or the phase difference between the forward displacement y and the steering angle θ, or the phase difference between the yaw angle φ and the steering angle θ.
This phase difference is defined by a time delay between a time change of the lateral displacement x (or a forward displacement y, the yaw angle φ) and a time change of the steering angle. FIG. 8 shows a temporal change of the yaw angle φ and a temporal change of the steering angle θ with respect to the lateral displacement amount x, the forward displacement amount y, and the traveling direction (lane mark). In general, when the lateral displacement amount x occurs, the driver performs steering in the reverse direction to eliminate the lateral displacement amount x. Therefore, the time change x (t) of the lateral displacement amount x and the time of the steering angle θ Since the time T until the driver perceives the lateral displacement x and specifically performs the steering is finite, the time variation of the lateral displacement x is different from the relationship θ (t). x (t) delayed steering change θ
(T) will occur. When the driver's consciousness level is high, the processing time from recognizing the lateral displacement amount x to steering is short, and thus the phase difference T is small. The phase difference T gradually increases. Therefore, in the present embodiment, the drowsy driving is detected by focusing on the increase in the phase difference T.

That is, the basic operation pattern analysis unit 22a
Then, the maximum value of these phase differences T during normal operation is calculated as a reference time and stored in the memory 22b (S2).
03). At this time, since the phase difference T changes according to the vehicle speed as in the first embodiment described above, a reference time for each vehicle speed is calculated and stored.

After a lapse of 5 minutes from the start of traveling, the comparator 22c compares the reference time with the current phase difference T, and compares the current phase difference T with the reference time as in the first embodiment. Is exceeded, the timer 22d starts time measurement, and again measures the return time until the phase difference T becomes equal to or less than the reference time (S205). When the driver's consciousness level decreases and the driver falls asleep, the return time increases. Therefore, the return time and a set value previously set for each vehicle speed and stored in the memory 22b (for example, 0 at 60 km / h). .8
Second), it is determined that the drowsy driving has occurred if the value is equal to or greater than the set value, and the alarm 28 is activated (S2).
06-S207). In addition, a second reference time (second reference time> reference time) is separately set in the comparator 22c, and when the phase difference T exceeds the second reference time, it is determined that the driver is dozing off,
The alarm 28 may be activated.

As described above, in the second embodiment, the amount of lateral displacement or the like is recognized (input), and the time difference (phase difference) until the corrective steering according to the amount of lateral displacement is performed is determined by the driver's consciousness. Focusing on the fact that it increases with a decrease in the level, the dozing driving is detected, so that the dozing driving is reliably detected regardless of the running route and according to the individual difference of the driver, as in the first embodiment described above. Can be. In addition, the drowsiness determination described in both embodiments is a determination based on a mere reference value, but may be determined based on how many times the above determination has occurred within a fixed time (for example, 5 minutes).

[0028]

As described above, according to the dozing driving detecting apparatus according to the present invention, dozing driving can be reliably detected irrespective of the runway and according to individual differences of drivers.
This has the effect of enabling safe driving.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of the present invention.

FIG. 2 is a block diagram showing another configuration of the present invention.

FIG. 3 is a configuration block diagram of one embodiment of the present invention.

FIG. 4 is an explanatory diagram of a lateral displacement amount, a forward displacement amount, and a yaw angle in the embodiment.

FIG. 5 is a processing flowchart of the embodiment.

FIG. 6 is a configuration block diagram of another embodiment of the present invention.

FIG. 7 is a processing flowchart of the embodiment.

FIG. 8 is a timing chart showing a phase difference in the embodiment.

[Explanation of symbols]

 Reference Signs List 20 image sensor 22 microcomputer 24 vehicle speed sensor 28 alarm 30 steering angle sensor

Continuation of the front page (56) References JP-A-60-15230 (JP, A) JP-A-4-56632 (JP, A) JP-A-5-85221 (JP, A) JP-A 64-83423 (JP) JP-A-1-124273 (JP, A) JP-A-2-21839 (JP, A) JP-A-59-38138 (JP, A) JP-A-60-157927 (JP, A) 3-204343 (JP, A) Japanese Utility Model sho 59-111735 (JP, U) Japanese Utility Model sho 64-40730 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 28/06 B60R 21/00 624 G08G 1/16

Claims (2)

(57) [Claims] 1. A position detecting means for continuously detecting a vehicle position with respect to a road, a reference value calculating means for calculating a reference value of the vehicle position during normal driving as a function of a vehicle speed, and after a lapse of a predetermined time from the start of traveling. First comparing means for comparing the vehicle position with the reference value; measuring means for measuring a return time when the vehicle position again becomes equal to or less than the reference value when the vehicle position exceeds the reference value; And a second comparing means for comparing the return time with a predetermined value. 2. A position detecting means for continuously detecting a vehicle position with respect to a runway; a steering angle detecting means for detecting a steering angle of a vehicle; and a time delay of a change in the steering angle with respect to a change in the vehicle position. Phase difference calculating means, reference value calculating means for calculating the reference time of the time delay during normal operation as a function of vehicle speed, and first comparing the time delay after a predetermined time has elapsed from the start of traveling with the reference time. Comparing means; measuring means for measuring a return time when the time delay exceeds the reference time again when the time delay exceeds the reference time; second comparing means for comparing the return time with a predetermined value A drowsy driving detection device, comprising: