JPH11208306A - Dangerous driving determination device for vehicles - Google Patents

Abstract

(57) [Summary] In a dangerous driving determination apparatus for a vehicle which determines the running stability of a vehicle from the meandering degree of the vehicle, false alarms when traveling on a curved road are reduced without lowering the sensitivity. A dangerous driving determination device for a vehicle that determines the running stability of a vehicle based on the yaw direction angular velocity of a vehicle, the rotation angle of a steering wheel, the lateral acceleration of the vehicle, or the running trajectory of the vehicle, wherein a current driving path is a curve. When it is detected that the vehicle is on a road, the threshold for determining the running stability is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for judging dangerous driving of a vehicle, and more particularly to an apparatus for judging dangerous driving when the running stability of the vehicle is reduced.

In recent years, safety awareness has risen in society, and safety devices for preventing traffic accidents have been demanded. Dangerous driving such as falling asleep, fatigue, and looking aside is one of the main factors of serious accidents. One. If such dangerous driving can be detected, the occurrence of an accident can be prevented beforehand. Therefore, many research institutions and automobile companies are studying these dangerous driving determining devices.

[0002]

2. Description of the Related Art Conventionally, a dangerous driving judging device directly judges a danger state of a driver and indirectly judges a danger state of a driver by judging a state in which the running stability of a vehicle is reduced. Is known. The former is a doze determination device or a fatigue determination device as disclosed in Japanese Patent Application No. 1-250221, and conventionally known determination methods use physiological information such as a driver's brain waves and blinks. .

[0003] The latter uses a running stability reduction judging means for judging how stable the vehicle is running without fluttering left and right (hereinafter referred to as a meandering degree).

A dangerous driving determination apparatus for a vehicle provided with such a means for determining a decrease in running stability determines the meandering degree of the vehicle and compares it with a reference value of the meandering degree expected in a normal state. Is high or low. That is, when the meandering degree is large, the running stability is determined to be low, and when the meandering degree is small, the running stability is determined to be high.

The meandering degree is obtained from (1) a change in the angular velocity of the vehicle in the left-right direction (hereinafter referred to as a yaw rate), a change in the rotation angle of the steering wheel, or (2) a deviation amount of the meandering from the running trajectory of the vehicle. be able to.

With respect to such a meandering degree, the operation principle of such a dangerous driving determination apparatus for a vehicle will be described below. (1) FIG. 7 shows an apparatus for judging dangerous driving of a vehicle using a yaw rate or a rotation angle of a steering wheel using a yaw direction angular velocity detection unit or a rotation angle detection unit, respectively.

FIG. 8A shows an example of a signal detected by the yaw direction angular velocity detecting means (or rotation angle detecting means) 2 shown in FIG. This detection signal includes information indicating whether the vehicle is traveling on a curved road or a straight road, in addition to the information indicating the meandering degree.

Therefore, it is necessary to exclude a curve component present in a relatively low frequency band from the detecting means 2 by using a frequency filter or the like. The signal from which the low-frequency component has been removed is shown in FIG.

[0009] In addition, the running stability reduction judging means 10
Is the instantaneous amplitude of the detection signal by the detection means 2 (large in the case of dangerous driving), the frequency of change (the number of inflection points per unit time; low in the case of dangerous driving), or a predetermined unit. The meandering degree is determined from the standard deviation within the time (large during dangerous driving) or the integrated value of the absolute value (the area of the portion painted black in FIG. 4).

[0010] Then, the running stability reduction judging means 10
By comparing the meandering degree with a preset threshold value of the meandering degree, a decrease in the running stability of the vehicle is determined.

(2) FIG. 9 shows a case in which a running locus measuring means for obtaining a deviation amount of meandering from a running locus of a vehicle is used. That is, as is well known, an image input unit, which is one example of the travel locus measuring unit 5, captures an image including a lane on the road on which the vehicle travels, processes the captured image by the signal processing unit 6, and processes the position of the lane. To identify. If the relative position deviation I between the center O of the vehicle and the center L of the lane is determined by the traveling stability decrease determining means 10, the traveling locus of the vehicle can be known.

The instantaneous amplitude of the running locus, the standard deviation of the running locus within a predetermined unit time, or the integrated value of the absolute value of the running locus (solid black in FIG. 8B). The traveling stability reduction determining means 10 determines the meandering degree based on the area of the part, and compares it with a predetermined threshold for the meandering degree to determine whether the traveling stability of the vehicle is reduced.

Further, as the traveling locus measuring means 5, a magnetic signal input means can be used in addition to the image input means. As a device that emits a magnetic signal, a magnetic coil or the like that is previously installed continuously on a road is cited.

In this case, if the signal of the magnetic coil is detected by the magnetic signal input means of the vehicle and the relative position between the vehicle and the magnetic coil is continuously obtained by the signal processing means 6 as is well known,
The traveling locus of the vehicle can be obtained. The subsequent operation principle is the same as in the case where the image input means is used.

Further, instead of the image input means, a radio signal input means can be used. As a device that emits a radio signal, there is a GPS satellite. The signal processing means 6 obtains the position of the vehicle in the same manner as the position detection as is well known in the navigation system. The subsequent operating principle is
This is the same as the case where the image input means is used.

[0016]

However, when such a conventional means for determining a decrease in the running stability of a vehicle is mounted on an actual vehicle as it is as a device for determining a dangerous driving of the vehicle, the state of the deterioration of the running stability of the vehicle and the driver It occurs when the danger state does not always correspond one-to-one. That is, depending on road conditions, the degree of meandering of the vehicle may increase, and a warning (false alarm) may be issued, although the driver's state is normal. This is because the meandering degree of the vehicle is an index that is greatly affected not only by the state of the driver but also by the driving environment.

Curve roads are a situation where erroneous reports are particularly frequent. As shown in FIG. 11, it is more difficult to accurately trace the center of the lane (L in FIG. 10) on the curved road CL than on the straight road SL, so the meandering degree of the vehicle increases.

If the number of false alarms is too large, the reliability of the device is significantly reduced, and the alarm may not be meaningful in an important situation. Therefore, reducing the number of false alarms is indispensable for improving the accuracy of the dangerous driving determination device.

As a method of reducing false alarms, a method of raising the judgment threshold value as a dangerous driving judgment apparatus for a vehicle so as to make it difficult to issue an alarm can be considered. However, the judgment at the time of really dangerous driving is delayed or leaked. So there is a safety problem. Conversely, if the judgment threshold value of the dangerous driving judgment device for the vehicle is lowered to make it easier to issue an alarm and the judgment of dangerous driving can be made earlier, false alarms will increase this time.

As described above, there is a trade-off between the problem of the false alarm and the determination threshold, and it has been difficult to satisfy both at the same time.

Accordingly, in view of the above problems, the present invention reduces an erroneous report when traveling on a curved road without lowering the sensitivity in a dangerous driving determination apparatus for a vehicle which determines the running stability of the vehicle from the meandering degree of the vehicle. The purpose is to:

[0022]

In order to achieve the above-mentioned object, a dangerous driving determination apparatus for a vehicle according to the present invention uses a yaw direction angular velocity of a vehicle detected by a yaw rate detecting means 2 as shown in FIG. In the dangerous driving determination device for a vehicle, in which the traveling stability decrease determining unit 1 determines the traveling stability of the vehicle, the traveling stability decrease determining unit 1 detects that the current traveling road is a curved road. It is characterized in that a threshold value for determining the running stability is raised.

That is, the traveling stability reduction determining means 1
When traveling on a curved road as compared with traveling on a straight road, the threshold value, which is a criterion for the determination, is increased so that the traveling stability of the vehicle is determined to be high if the meandering degree is the same.

Further, in the present invention, as shown in FIG. 2, a rotation angle detecting means 3 is used in place of the above yaw rate detecting means 2, and the steering wheel detected by the rotation angle detecting means 3 in place of the yaw direction angular velocity. In the dangerous driving determination device for a vehicle, in which the traveling stability decrease determining unit 1 determines the traveling stability of the vehicle from the rotation angle, the traveling stability decrease determining unit 1 detects that the current traveling road is a curved road. At this time, a threshold for determining the running stability may be increased.

Further, in the present invention, as shown in FIG. 3, the running stability of the vehicle is determined from the lateral acceleration of the vehicle detected by the lateral acceleration detecting means 4 instead of the yaw rate detecting means 2 or the rotation angle detecting means 3. In the dangerous driving determination device for a vehicle, which is determined by the traveling stability decrease determining unit 1, the traveling stability decrease determining unit 1 determines the traveling stability when detecting that the current traveling road is a curved road. May be increased.

Further, in the present invention, as shown in FIG. 4, the traveling stability decrease judging means 1 determines the meandering degree of the vehicle based on the traveling locus of the vehicle detected by the traveling locus measuring means 5 and obtained from the signal processing means 6. In the apparatus for determining a dangerous driving of a vehicle which determines the traveling stability, the traveling stability detecting means 7 further includes a curved road traveling detecting means 7. When it is detected that the vehicle is on a road, a threshold value for determining the traveling stability can be increased.

That is, in the case of FIG. 4, since the traveling locus measuring means 5 is used, the curved road detecting means 7 is separately required. When it is determined that the current traveling road is a curved road, the threshold value for determining the traveling stability is increased in the same manner as in FIGS.

As the traveling locus measuring means 5, any one of image input means, magnetic signal input means, and radio signal input means may be used. Further, as the above-mentioned curved road detecting means, a turning angle detecting means for detecting a turning angle of a steering wheel or a yaw rate detecting means for detecting a yaw direction angular velocity of the vehicle may be used.

[0029]

FIG. 5 shows an embodiment of a calculation processing flow in the dangerous driving determination apparatus for a vehicle according to the present invention shown in FIGS. In this embodiment, a drowsy driving detection device is particularly used as a dangerous driving determination device. Hereinafter, the operation of the embodiment of the present invention will be described with reference to this flow.

In FIG. 5, first, the yaw rate is detected by the yaw direction angular velocity detecting means 2 used in FIG. 1 (step S1). The running stability reduction determining means 1 which has received the yaw rate detection signal obtains a change (deviation) in the short time as in the conventional case. The minute time deviation of the yaw rate (hereinafter simply referred to as the deviation of the yaw rate) is a detection signal ((1) in FIG. 8) as shown in FIG.
From which the curve road component is excluded, and can be obtained using a frequency filter or the like.

Then, the traveling stability reduction judging means 1 calculates the meandering degree d of the vehicle from the yaw rate deviation in the same manner as in the prior art (step S2). When the driver is normal, the deviation of the yaw rate is small because the meandering degree d of the vehicle is small, and the deviation of the yaw rate is large during the drowsy driving and the fatigue driving because the meandering degree d of the vehicle is large.

Therefore, based on the meandering degree d of the vehicle calculated in this way, the running stability reduction determining means 1 determines whether the vehicle is in a drowsy driving mode or a tired driving mode. It is determined whether the vehicle is traveling on a straight road or a curved road (step S3).

The determination as to whether the vehicle is traveling on a curved road or a straight road is made by the traveling stability reduction determining means 1 based on a temporal change of the yaw rate detected by the yaw direction angular velocity detecting means 2. That is, while traveling on a curved road, the yaw rate equal to or higher than a predetermined value continues for several seconds, but does not continue during traveling on a straight road. This is because, as shown in FIG. 8A, the fact that the yaw rate equal to or higher than the predetermined value continues for a few seconds while traveling on a straight road means a lane departure. Therefore, when the yaw rate equal to or higher than the predetermined value continues for several seconds, it may be determined that the vehicle is traveling on a curved road.

As described in the section of the prior art, the meandering degree d
Is the instantaneous amplitude of the yaw rate deviation signal, the standard deviation of the traveling locus within a predetermined unit time, or the integrated value of the absolute value of the traveling locus (the area of the black portion in FIG. 8B). And so on. Therefore, the traveling stability decrease determining means 1 further increases the meandering degree d of the vehicle while traveling on a curved road.
At the time of traveling on a straight road (step S4). As an example of this conversion, the meandering degree d when traveling on a straight road can be calculated as follows: the meandering degree d when traveling on a curved road x a correction coefficient (eg, 0.8).

Thereafter, the traveling stability reduction determining means 1 compares the corrected meandering degree d with a threshold D for determination in order to determine dangerous driving of the vehicle using the converted value (step S5). As a result, if d ≦ D, it is determined that the driver is awake (step S6), and if d> D, it is determined that the driver is dozing (step S7).

In this way, the traveling stability reduction determining means 1 can determine the dangerous driving of the vehicle on a curved road or a straight road with the same sensitivity.

Further, in the dangerous driving judging device according to the present invention, as shown in FIG. 2, the yaw direction angular velocity detecting means 2 may be replaced with a steering wheel rotation angle detecting means 3. In this case, the traveling stability decrease determination means 1 uses the rotation angle instead of the yaw direction angular velocity, and focuses on a minute temporal change in the rotation angle.

That is, the running stability reduction determining means 1 calculates the meandering degree d representing the stability of the vehicle from the rotation angle detection signal from the rotation angle detecting means 3 (step S1, step S1).
S2), pay attention to this temporal change. In the awake state, the meandering degree d is small and it can be expected that the vehicle is traveling smoothly. However, in the dangerous driving state, the meandering degree d increases and it can be expected that the vehicle is traveling dangerously.

Further, it is determined whether the vehicle is traveling on a straight road or a curved road from the detection signal of the rotation angle detecting means 3 (step S3). Similar to the above-described determination of a curved road based on the yaw rate, a rotation angle equal to or more than a predetermined value continues for several seconds on a curved road, but does not continue during traveling on a straight road. Therefore, it may be determined that the vehicle is traveling on a curved road when the rotation angle equal to or more than the predetermined value continues for several seconds.

Thereafter, the traveling stability decrease determining means 1 converts the meandering degree d of the vehicle when traveling on a straight road as in the case of using the yaw direction angular velocity detecting means 2 (step S4). Dangerous driving of the vehicle is determined based on the converted value, so that dangerous driving of the vehicle can be determined with the same sensitivity on both a curved road and a straight road.

Further, in the dangerous driving judging device according to the present invention, as shown in FIG. 3, a lateral acceleration detecting means 4 may be used instead of the yaw direction angular velocity detecting means 2. The relationship between the yaw rate and the lateral acceleration (lateral G) will be described with reference to FIG. 6. When the vehicle is turning on a curved road, the turning center O is set.
On the circle drawn around, the actual speed V goes in the circumferential direction, but the lateral acceleration Gy slightly deviates in direction from the centripetal acceleration Gc (generally, it can be considered almost equal). The yaw rate R is an angular velocity about the vertical axis of the vehicle.

In this way, the same processing as in the example of FIG. 1 may be performed using the lateral acceleration instead of the yaw rate.

In the dangerous driving determining apparatus according to the present invention, as shown in FIG.
Instead, an image input unit, a magnetic signal input unit, or a radio signal input unit may be used as the traveling locus measuring unit 5, which is the same as the case of the conventional example in FIG. In this case, after signal processing is performed by the signal processing means 6 for calculating the traveling locus of the vehicle from the detection signal of the input means, a small temporal change in the traveling locus is focused on, and the driving stability reduction determining means is determined. 1 determines the meandering degree d.

However, in this example, unlike the examples shown in FIGS. 1 to 3, the traveling stability reduction judging means 1 itself cannot detect the traveling on a curved road from the output signal of the signal processing means 6. Therefore, a curved road traveling detection means 7 is separately provided, and step S3 in FIG. 5 is determined based on an output signal of the curved road traveling detecting means 7. Other processes are the same as the above.

As the curve road detecting means, the yaw rate detecting means for detecting the angular velocity of the vehicle in the yaw direction shown in FIG. 1 or the rotational angle detecting means for detecting the rotational angle of the steering wheel shown in FIG. 2 may be used.

[0046]

As described above, according to the vehicle running stability reduction judging means according to the present invention, the yaw direction angular velocity of the vehicle, the rotation angle of the steering wheel, the lateral acceleration of the vehicle,
Alternatively, in a dangerous driving determination apparatus for a vehicle that determines the running stability of the vehicle based on the running trajectory of the vehicle, when it is detected that the current running road is a curved road, the threshold value for determining the running stability is increased. With such a configuration, it is possible to reduce false reports that lower the sensitivity of determination of dangerous driving, and thus to increase the accuracy of determination of dangerous driving.

[Brief description of the drawings]

FIG. 1 is a block diagram showing in principle a dangerous driving determination apparatus (1) for a vehicle according to the present invention.

FIG. 2 is a block diagram showing in principle a dangerous driving determination device (2) for a vehicle according to the present invention.

FIG. 3 is a block diagram showing in principle a dangerous driving determination device (3) for a vehicle according to the present invention.

FIG. 4 is a block diagram showing in principle a dangerous driving determination device (4) for a vehicle according to the present invention.

FIG. 5 is a flowchart illustrating an example of a calculation process of the dangerous driving determination device for a vehicle according to the present invention.

FIG. 6 is a diagram for explaining a relationship between a yaw rate and a lateral acceleration.

FIG. 7 is a block diagram showing in principle a dangerous driving determination apparatus (1) for a vehicle according to a conventional example.

FIG. 8 is a waveform diagram showing an example of a signal detected by each detecting means in the dangerous driving determination apparatus for a vehicle according to the present invention and the conventional example.

FIG. 9 is a block diagram showing in principle a dangerous driving determination device (2) for a vehicle according to a conventional example.

FIG. 10 is a diagram illustrating a method of specifying a lane and obtaining a traveling locus.

FIG. 11 is a graph showing a comparison of meandering degrees.

[Explanation of symbols]

1, 10 Running stability reduction determining means 2 Yaw direction angular velocity detecting means 3 Rotating angle detecting means 4 Lateral acceleration detecting means 5 Running locus measuring means (image input means / magnetic signal input means / radio wave signal input means) 6 Signal processing means 7 Curved road travel detecting means In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (6)

[Claims] 1. A dangerous driving determination device for a vehicle, wherein a driving stability reduction determining means determines a driving stability of the vehicle based on the yaw direction angular velocity of the vehicle detected by the yaw rate detecting means. A dangerous driving determination device for a vehicle, wherein when detecting that a current traveling road is a curved road, a threshold value for determining the traveling stability is increased. 2. A dangerous driving determination device for a vehicle, wherein the driving stability reduction determining means determines the driving stability of the vehicle from the rotation angle of the steering wheel detected by the rotation angle detecting means. A dangerous driving determination apparatus for a vehicle, which increases a threshold value for determining the running stability when detecting that a current running road is a curved road. 3. A dangerous driving determination apparatus for a vehicle, wherein the driving stability decrease determining means determines the running stability of the vehicle from the lateral acceleration of the vehicle detected by the lateral acceleration detecting means. A dangerous driving determination device for a vehicle, wherein when detecting that a current traveling road is a curved road, a threshold value for determining the traveling stability is increased. 4. A dangerous driving determination of a vehicle in which the traveling stability decrease determining means determines the running stability by obtaining the meandering degree of the vehicle based on the traveling locus of the vehicle detected by the traveling locus measuring means and obtained from the signal processing means. The apparatus further includes a curved road traveling detection unit, and the traveling stability decrease determining unit determines the traveling stability when the current traveling road is a curved road detected by the curved road traveling detecting unit. Dangerous driving determination device for a vehicle, characterized by increasing a threshold value for the vehicle. 5. A dangerous driving determination apparatus for a vehicle according to claim 4, wherein said travel locus measuring means is one of an image input means, a magnetic signal input means, and a radio signal input means. 6. A vehicle according to claim 4, wherein said curved road detecting means is a rotation angle detecting means for detecting a rotation angle of a steering wheel or a yaw rate detecting means for detecting a yaw direction angular velocity of the vehicle. Dangerous driving determination device.