JP2970384B2 - 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 corrected steering cycle of a vehicle.

[0002]

2. Description of the Related Art Conventionally, various devices have been developed and mounted for the purpose of improving the safety of running a vehicle, and a drowsiness detection device which detects a driver's drowsiness and generates an alarm is one of them. .

[0003] As a method of detecting a drowsy driving, there are a method of photographing a driver's face image, a method of measuring a driver's pulse, and a method of detecting a steering state of a vehicle. For example, Japanese Patent Application Laid-Open No. 60-76424 discloses that a drowsy driving is detected when the steering wheel is turned by a certain angle, and Japanese Patent Application Laid-Open No. 60-157927 discloses that steering is performed within a predetermined time. It shows that the drowsy driving is detected because the high-frequency component of the angle change is equal to or more than a predetermined value.

[0004] However, in these conventional techniques, there is a problem that a curve traveling is erroneously detected as a drowsiness driving, and a high-frequency component cannot be detected with sufficient accuracy because the high frequency component is generated other than during the drowsiness driving.

Accordingly, the applicant of the present application has paid attention to the fact that there is a correlation between the driver's consciousness level and the corrected steering cycle, and first calculates the corrected steering cycle in Japanese Patent Application No. 4-254694. A configuration for detecting a drowsy driving in comparison with a normal cycle (reference cycle) has been proposed.

[0006]

However, it is not always easy to calculate the correction steering cycle from the detected steering angle data. For example, it is conceivable that the obtained steering angle signal is time-differentiated, and a point at which the steering angle signal becomes zero is corrected steering. There is a risk of detection. In such a case, the corrected steering cycle is generally shortened, and there is a possibility that the drowsy driving cannot be detected in spite of the dozing state.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems of the prior art, and has as its object to accurately detect a corrected steering point from an obtained steering angle signal and accurately detect a corrected steering cycle of a driver. Another object of the present invention is to provide a drowsy driving detection device capable of detecting a drowsiness using the corrected steering cycle.

[0008]

According to a first aspect of the present invention, there is provided a dozing driving detecting device for detecting a driver's dozing from a running state of a vehicle. Steering angle detection means for detecting a steering angle,
A steering cycle calculating means for calculating a corrected steering cycle from the detected steering angle signal; and a comparing means for comparing the corrected steering cycle with a reference cycle, wherein the steering cycle calculating means comprises: Delay means for delaying the signal for a predetermined time;
A difference means for calculating a difference between the detected steering angle signal and the delay signal from the delay means; and a detection means for detecting a zero point from a change in the sign of the difference output from the difference means. .

In order to achieve the above object, a doze driving detecting apparatus according to claim 2 is the dozing driving detecting apparatus according to claim 1, wherein the detecting means sets the zero point of the differential output. The change of the sign is detected using the predetermined positive threshold value and negative threshold value.

According to another aspect of the present invention, there is provided a dozing driving detecting apparatus according to claim 1 or 2, wherein the detecting means comprises an absolute value of the differential output. Is used.

According to another aspect of the present invention, there is provided a drowsy driving detecting apparatus as set forth in claim 1, 2, 3 or 4.
The delay means reduces the delay time when the vehicle is traveling on a curved road.

In order to achieve the above object, a drowsy driving detection device according to claim 5 is a drowsing driving detection device according to claim 1, 2 or 3, wherein the delay means comprises: The delay time is changed according to the value of the difference output.

According to a sixth aspect of the present invention, there is provided a dozing driving detecting apparatus according to the sixth aspect, further comprising an integrated value of a positive output and a negative output of the difference output. And an integral value comparing means for comparing a positive integral value and a negative integral value, wherein the delay means changes the delay time according to a comparison result from the integral value comparing means. And

According to a seventh aspect of the present invention, there is provided a dozing driving detecting apparatus according to the second aspect, further comprising an integral value of each of a positive output and a negative output of the differential output. And an integral value comparing means for comparing a positive integral value and a negative integral value, wherein the detecting means comprises a positive threshold value and a negative threshold value in accordance with a comparison result from the integral value comparing means. Is changed.

According to another aspect of the present invention, there is provided a drowsy driving detecting apparatus as set forth in claim 1, 2, 3 or 4.
Further, there is provided a gain control means for changing an amplification gain of the steering angle signal when the vehicle is traveling on a curved road.

According to a ninth aspect of the present invention, there is provided a dozing driving detecting apparatus according to the first or second or third aspect.
When the vehicle is traveling on a curved road, the comparing means changes the reference cycle.

According to a tenth aspect of the present invention, there is provided a drowsy driving detection apparatus according to the eighth or ninth aspect, further comprising a positive output and a negative output of the differential output. An integral means for calculating each integral value, and an integral value comparing means for comparing a positive integral value and a negative integral value, wherein a curve course is detected based on a comparison result by the integral value comparing means. .

[0018]

According to the present invention, the steering angle signal is delayed by a predetermined time, and the difference between the steering angle signal and the delay signal is calculated. Generally, the corrected steering point appears as a top (maximum) and a bottom (minimum) point of the steering angle signal. Therefore, by performing the difference calculation, a zero point is generated in the difference output when the top or bottom occurs. Then, the zero point is nothing but the timing information of the top or bottom of the steering angle signal, and indicates the corrected steering cycle.

The zero point of the difference output can be detected from a change in the sign of the difference output. This is because the zero point occurs only because of the sign change. The change in the sign can be detected by comparing the difference output with the positive threshold value and the negative threshold value near the output zero. By appropriately setting the threshold value, it is possible to prevent a weak return such as a steering reaction force from being detected as a zero point, and to accurately detect a corrected steering cycle.

According to a third aspect of the present invention, there is provided a dozing driving detecting apparatus.
A zero point of the difference output is detected by comparing the absolute value of the difference output with a predetermined threshold value near zero. By using the absolute value of the difference output, the zero point can be detected with only one threshold value, and the zero point detection process is simplified.

According to a fourth aspect of the present invention, the drowsy driving detection device changes a delay time for generating a delay signal according to a traveling road. When the vehicle is traveling on a curved road, the burden on the driver task is large, and the steering amount fluctuates frequently. Therefore, even with the same delay time, the value of the differential output increases on a curved road compared to a straight road. As described above, the difference output becomes large on the curved road, and therefore, the detection of the zero point by the detection means is inconsistent. Therefore, on a curved road, the delay time is reduced and the difference output value is maintained within a certain range.

According to a sixth aspect of the present invention, there is provided a drowsy driving detection device, wherein a positive integral value and a negative integral value of the difference output are calculated.
These magnitude comparisons are performed. When the vehicle is traveling on a curved road, the steering angle signal also has left and right deviations, and thus the difference output also has positive and negative deviations due to the left and right deviations. Therefore, by comparing the magnitudes of the positive integral value and the negative integral value, it is determined whether the vehicle is traveling on a curved road, and further, is traveling on a right curved road or a left curved road. Can be. If a positive or negative deviation occurs in the difference output, the delay time is changed, or the positive threshold value and the negative threshold value are changed. Specifically, when the positive integral value is larger than the negative integral value, the positive threshold value is set larger than the negative threshold value. As a result, it is possible to prevent a decrease in the zero point detection accuracy due to the deviation of the difference output.

[0023] In the dozing driving detecting device according to claim 8,
As described above, the differential output increases on a curved road, so that the amplification gain of the steering angle signal is reduced to keep the differential output value within a certain range.

[0024] In the dozing driving detecting device according to the ninth aspect,
On a curved road, the burden on the driver task is large, and the corrected steering cycle tends to be short. Therefore, on a curved road, the driver's dozing state can be reliably detected by setting a short reference period for determining the driver's consciousness reduction.

According to a tenth aspect of the present invention, the doze driving detection device detects a curved lane by comparing the magnitudes of the positive and negative integral values. As described above, when the vehicle is traveling on a curved road, the steering angle signal also has left and right deviations, and thus the difference output also has positive and negative deviations due to the left and right deviations. Accordingly, by comparing the positive integral value and the negative integral value, it is possible to detect whether or not the vehicle is traveling on a curved road without using a G sensor or the like.

[0026]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention.

First Embodiment FIG. 1 shows the overall configuration of a drowsy driving detection device according to this embodiment. In the figure, a steering angle sensor 10 is provided on a steering shaft or the like of a vehicle and sequentially detects a steering angle. The detected steering angle signal is output to the corrected steering cycle measuring unit 12. The corrected steering cycle measuring unit 12 extracts a corrected steering point by performing processing described later, and measures the cycle. The measured corrected steering cycle is output to the consciousness reduction determining unit 14. The consciousness lowering determination unit 14 compares the reference cycle during normal operation with the measured corrected steering cycle, and determines that the driver's consciousness has decreased if the reference cycle is longer than the reference cycle,
An alarm activation signal is output to the alarm unit 16. The warning unit 16 generates a warning based on the warning operation signal to urge the driver's attention. Although not shown, it is also possible to adopt a configuration in which a control signal is output from the consciousness reduction determining unit 14 to a brake actuator or the like, and deceleration control is automatically performed when it is determined that the driver's consciousness has been reduced. .

FIG. 2 shows the configuration of the correction steering cycle measuring section 12 in the present embodiment. The correction steering cycle measuring unit 12 in the present embodiment includes a delay circuit 12a for delaying the steering angle signal output from the steering angle sensor 10 for a predetermined time, a difference circuit 12b for calculating a difference between the steering angle signal and the delay signal, and a predetermined circuit. It comprises a threshold circuit 12c for detecting a zero point of a difference signal using a threshold value. The delay time in the delay circuit 12a is set to, for example, 0.2 sec.
Output to FIG. 3 shows the steering angle signal 100 input to the difference circuit 12b and the delay signal 102 output from the delay circuit 12a. In FIG. 3, the horizontal axis represents time t, and the vertical axis represents a steering angle signal (steering angle fluctuation amount). The difference circuit 12b calculates the difference between the steering angle signal 100 and the delay signal 102, and outputs the difference signal to the threshold circuit 12c. Note that τ in FIG. 3 indicates a delay time.

On the other hand, FIG. 4 shows an example of a difference output outputted from the difference circuit 12b to the threshold circuit 12c. In the figure, the horizontal axis represents time t, and the vertical axis represents difference output. A solid line indicated by reference numeral 104 indicates a difference signal, a two-dot chain line 500 indicates a predetermined threshold level on the positive side, and a two-dot chain line 502 indicates a predetermined threshold level on the negative side. I have. The threshold circuit 12c converts the difference signal into a pulse signal using these positive and negative thresholds. At this time, the threshold circuit 12c converts the signal into a pulse signal by the hysteresis characteristic. That is, the pulse falls when the pulse signal falls below the threshold value 502 from the positive side to the negative side, while the pulse signal falls when the difference signal goes above the threshold level 500 from the negative side to the positive side. Is converted into a pulse signal with a hysteresis characteristic such that rises. FIG. 5 shows an example of an output waveform converted into a pulse signal as a result of such hysteresis characteristics. In FIG. 5, the horizontal axis represents time t,
The vertical axis indicates the output.

Generally, the driver's corrected steering point will appear as the top or bottom of the steering angle signal. Therefore, when the steering angle signal includes the top or bottom, a zero point is generated in the difference output between the steering angle signal and the delay signal, and this zero point is the top or bottom of the steering angle signal. It will provide timing information. In FIG. 5, becomes the pulse falling point or pulse rise point, indicates the zero point of the differential signal, the rise of the pulse, fall time _{t x, t x + 1,} t x + 2, t
_{t + 3} will provide the timing information for the corrected steering point.

Here, even if the steering angle signal includes a weak turnback due to a steering reaction force caused by road surface irregularities or the like, the difference signal includes a zero point as shown in FIG. However, if the zero point is detected by the threshold circuit 12c having the above-described hysteresis characteristic, the corrected steering cycle can be reliably measured without erroneously detecting a weak switching as a corrected steering point.

Second Embodiment FIG. 6 shows the configuration of the correction steering cycle measuring section 12 in the embodiment. The correction steering cycle measuring unit 12 of the present embodiment includes a delay circuit 12a, an absolute difference circuit 12d, and a threshold circuit 12c. The delay circuit 12a delays the steering angle signal output from the steering angle sensor 10 for a predetermined time (for example, 0.2 sec) and outputs the same to the absolute difference circuit 12d, similarly to the delay circuit in the first embodiment described above. The difference absolute value circuit 12d calculates the difference between the steering angle signal and the delay signal, and outputs the magnitude (that is, the absolute value) to the threshold value circuit 12c. The threshold circuit 12c compares the difference output from the difference absolute value circuit 12d with a predetermined threshold and outputs a pulse signal.

FIG. 7 shows the difference signal and the threshold level input to the threshold circuit 12c. In the figure, the horizontal axis represents time t, and the vertical axis represents difference output.
The solid line 106 indicates the difference output, and the two-dot chain line 504 indicates the threshold level. By generating a pulse signal when the difference output falls below the threshold level 504 near zero, a pulse waveform as shown in FIG. 8 is obtained. Then, as in the first embodiment described above, the rise or fall of this pulse waveform represents the zero point of the difference signal, that is, the corrected steering point.

Also in this embodiment, a weak return such as a steering reaction force is not detected as a corrected steering point by appropriately setting the threshold level 504, and an accurate corrected steering cycle can be detected. In this embodiment, it is needless to say that the influence of the disturbance can be more reliably removed by providing the threshold circuit 12c with the hysteresis characteristic as in the first embodiment.

Third Embodiment FIG. 9 shows the configuration of the modified steering cycle measuring section 12 of this embodiment. The modified steering cycle measuring section in the present embodiment is composed of a delay circuit 12a, a difference circuit 12b, and a threshold circuit 12c, as in the first embodiment.
The delay circuit 12a delays the steering angle signal and outputs the delayed signal to the difference circuit 12b. The difference circuit 12b calculates the difference between the steering angle signal and the delay signal to calculate the difference between the steering angle signal and the delay signal.
Output to The threshold circuit 12c converts the difference signal into a pulse signal using the positive threshold value and the negative threshold value, and outputs the pulse signal.

Here, in the present embodiment, the difference circuit 1
A part of the difference signal from 2b is fed back to the delay circuit 12a, and the delay time in the delay circuit 12a is controlled. As described above, when the vehicle is traveling on a curved road, the fluctuation of the steering angle is larger than when the vehicle is traveling on a straight road. Therefore, the difference output from the difference circuit 12b is equal at the same delay time. growing. Therefore,
When the same threshold level is set in the threshold circuit 12c, it becomes difficult to remove the influence of disturbance or the like and extract an accurate corrected steering point. Therefore, in order to suppress the level of the differential signal output from the differential circuit 12b within a predetermined range, the delay time in the delay circuit 12a is increased or decreased. As an adjustment method, the difference circuit 12b
If the differential output from is large, reduce the delay time,
When the difference output is small, the delay time in the delay circuit 12a is set to be long. FIG. 10 shows the steering angle signal 102, a delay signal 104 obtained by delaying the steering angle signal by a first delay time, and a delay signal 108 obtained by delaying the steering angle signal by a second delay time. Reference numeral 108 denotes a delay signal when the vehicle is traveling on a straight road.
Corresponds to a delay signal when traveling on a curved road.

As described above, in this embodiment, a part of the difference signal from the difference circuit 12b is fed back to the delay circuit 12a, and the delay time of the delay circuit 12a is feedback-controlled. Is within a certain range, and the corrected steering cycle can be accurately measured using the same threshold value.

Fourth Embodiment FIG. 11 shows the configuration of the modified steering cycle measuring section 12 in this embodiment. In the present embodiment, the correction steering cycle measuring unit 12 includes an integrator 12e and a comparator 12f in addition to the delay circuit 12a, the difference circuit 12b, and the threshold circuit 12c. The integrator 12e is a differential circuit 12
The integration of the positive side signal and the integration of the negative side signal of the difference signal output from b are performed, and the positive integration value and the negative integration value are compared with the comparator 1
Output to 2f. The comparator 12f compares the positive integral value and the negative integral value output from the integrator 12e, and outputs the result of the comparison to the threshold circuit 12c.

The delay circuit 12a and the difference circuit 12b in this embodiment perform the same operations as in the first embodiment, delay the steering angle signal by a predetermined time, and calculate the difference from the steering angle signal. FIG. 12 shows the steering angle signal 102 and the delay signal 104 input to the difference circuit 12b. FIG. 12 corresponds to FIG. 3 described above. Difference circuit 1
2b calculates a difference between the steering angle signal 102 and the delay signal 104, and outputs a difference output to the threshold circuit 12c and the integrator 12e. FIG. 13 shows an example of the difference output output from the difference circuit 12b. Reference numeral 110 in the figure
The solid line indicated by is a difference signal. The delay time is 0.2 sec as in the first embodiment.

The integrator 12e outputs the difference signal 11
The integral value of each of the positive side and the negative side of 0 is calculated. FIG. 14 shows a positive integration output and a negative integration output sequentially output from the integrator 12e to the comparator 12f. The comparator 12f compares such a positive integration output and a negative integration output, and outputs a time change of the comparison value to the threshold circuit 12c. That is, the comparator 12f compares the positive and negative values with the product of each of the positive and negative continuation time intervals and the final integral value as the respective value, and outputs the result to the threshold circuit 12c. The threshold circuit 12c changes the positive threshold value and the negative threshold value by multiplying the comparison output value output from the comparator 12f by a predetermined coefficient. Specifically, the threshold circuit 12
c performs control to increase the larger threshold value of the comparison output value. When the vehicle is traveling on a curved road, a left-right deviation occurs in the steering angle signal, so that a difference occurs between the positive integral value and the negative integral value from the integrator 12e. Therefore, the comparison output value from the comparator 12f indicates that the steering angle signal has a left-right deviation, that is, that the vehicle is currently traveling on a curved road. By changing the level in accordance with the left and right deviation of the steering angle signal, it is possible to accurately measure the corrected steering cycle.

In the present embodiment, the threshold level of the threshold circuit 12c may be changed from the value of the change tendency of the positive / negative value deviation in several cycles in the past.

Fifth Embodiment FIG. 15 shows the configuration of the modified steering cycle measuring section 12 of this embodiment. In this embodiment, as in the above-described fourth embodiment, a delay circuit 12a, a difference circuit 12b, a threshold circuit 12c, an integrator 12e, and a comparator 12f are provided. , A part of the comparison output value from the comparator 12f is fed back to the delay circuit 12a. Then, the delay time in the delay circuit 12a is controlled to increase or decrease according to the comparison output value from the comparator 12f.

As described above, the comparison output value from the comparator 12f can serve as an identification signal for determining whether the vehicle is currently traveling on a curved road or a straight road. That is, the comparator 12
When the comparison output value from f is equal to or more than a certain value, the delay time in the delay circuit 12a is set to be small, and the level of the difference signal output from the difference circuit 12b can be suppressed to a certain range. Becomes As a result, the zero point detection in the threshold circuit 12c is further facilitated, and the correct steering cycle can be accurately measured.

Sixth Embodiment FIG. 16 shows the structure of a sixth embodiment of the present invention.
The correction steering cycle measuring unit 12 in this embodiment includes a delay circuit 12a and a difference circuit 12 as in the fourth and fifth embodiments.
b, threshold circuit 12c, integrator 12e, and comparator 1
2f. Then, in the present embodiment, a part of the comparison output from the comparator 12f is output to the consciousness reduction determining unit 14, and the reference cycle in the consciousness reduction determining unit 14 is increased or decreased according to the comparison output value.

Generally, when the vehicle is traveling on a curved road, the smaller the radius of the curve, the greater the burden on the driver task, and the shorter the corrected steering cycle. Therefore, when traveling on a curved road, it is necessary to set a shorter reference period in normal times, which is a criterion for determining a decrease in consciousness, than when traveling on a straight road. For this reason, in the present embodiment, the comparison output from the comparator 12f indicating that the vehicle is traveling on a curved road is used, and the reference period is increased or decreased according to the output value of the comparison output. Specifically, the larger the comparison output value from the comparator 12f, the shorter the reference cycle is set. Thus, even when the vehicle is traveling on a curved road, it is possible to detect a decrease in the driver's consciousness with the same accuracy as when the vehicle is traveling on a straight road.

In this embodiment, the comparison output from the comparator 12f is supplied to the delay circuit 12a and the threshold circuit 12c.
Although the configuration for outputting to the consciousness reduction determining unit 14 has been described, the configuration is such that the comparison output from the comparator 12f is output to an amplifier or the like provided in the preceding stage of the delay circuit 12a, and the gain of the amplifier is increased or decreased according to the comparison output value. It is also possible.

Seventh Embodiment FIG. 17 is a block diagram showing a configuration in which the gain of an amplifier is increased or decreased according to the comparison output value. The correction steering cycle measuring unit 12 in this embodiment also includes a delay circuit 12a, a difference circuit 12b, a threshold circuit 1
2c, an integrator 12e, and a comparator 12f. In this embodiment, a part of the output from the comparator 12f is provided by an amplifier 1 provided at a stage subsequent to the steering angle sensor 10.
1 and the gain is increased or decreased based on the output of the comparator 12f.

On a curved road, as described above, the difference output value increases, so that it is difficult to make a judgment by the threshold circuit. Therefore, when the comparison output value from the comparator 12f is equal to or more than a certain value, the gain of the amplifier 11 is reduced, and the level of the difference signal output from the difference circuit 12b can be suppressed within a certain range. . The degree of the decrease may be linearly decreased according to the comparison output value, or may be decreased by an arbitrary functional relationship. This allows
Threshold circuit 12c regardless of the curve radius of the curved road
Detecting the zero point is facilitated, and accurate measurement of the corrected steering cycle becomes possible.

In FIG. 17, the output of the comparator 12f is also supplied to a threshold circuit 12c, so that both the amplification factor and the threshold can be adjusted. Adjusting the amplification rate alone is enough to be effective,
By mutually adjusting the parameters of the system in this way, it is possible to detect the corrected steering cycle with high accuracy.
Further, the output of the comparator 12f may be supplied to the delay circuit 12a and the difference circuit 12B so that each parameter is mutually adjusted.

[0050]

As described above, according to the dozing driving detecting apparatus according to the first to tenth aspects, the corrected steering cycle can be detected stably and accurately, whereby the dozing state of the driver can be detected. Can be reliably detected.

Therefore, by incorporating the drowsy driving detection device of the present invention into a vehicle safety system, the reliability of the system can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration block diagram of a corrected steering cycle measuring unit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a steering angle signal and a delay signal thereof according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a difference output in the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of an output of the threshold circuit according to the first embodiment of the present invention.

FIG. 6 is a configuration block diagram of a corrected steering cycle measuring unit according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a difference output in the second embodiment of the present invention.

FIG. 8 is an explanatory diagram of an output of a threshold circuit according to a second embodiment of the present invention.

FIG. 9 is a configuration block diagram of a corrected steering cycle measuring unit according to a third embodiment of the present invention.

FIG. 10 is an explanatory diagram of a steering angle signal and its delay signal in a third embodiment of the present invention.

FIG. 11 is a configuration block diagram of a modified steering cycle measuring unit according to a third embodiment of the present invention.

FIG. 12 is an explanatory diagram of a steering angle signal and its delay signal in a fourth embodiment of the present invention.

FIG. 13 is an explanatory diagram of a differential signal according to a fourth embodiment of the present invention.

FIG. 14 is an explanatory diagram of an output of an integrator according to a fourth embodiment of the present invention.

FIG. 15 is a configuration block diagram of a correction steering cycle measuring unit according to a fifth embodiment of the present invention.

FIG. 16 is a configuration block diagram of a correction steering cycle and consciousness reduction determining unit according to a sixth embodiment of the present invention.

FIG. 17 is a configuration block diagram of a correction steering cycle and consciousness reduction determining unit according to a seventh embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 Steering angle sensor 11 Amplifier 12 Corrected steering cycle measuring unit 14 Awareness reduction judgment unit 16 Alarm unit

Continuation of front page (56) References JP-A-60-76424 (JP, A) JP-A-60-157927 (JP, A) JP-A-3-204343 (JP, A) JP-A-5-85221 (JP) JP-A-5-58192 (JP, A) JP-A-5-155269 (JP, A) JP-A-59-153625 (JP, A) JP-A-60-151134 (JP, A) (58) Surveyed field (Int. Cl. ⁶ , DB name) B60K 28/00-28/16 G08B 19/00-21/00

Claims (10)

(57) [Claims] 1. A drowsiness driving detection device for detecting a driver's drowsiness from a running state of a vehicle, a steering angle detection means for detecting a steering angle of the vehicle, and calculating a corrected steering cycle from the detected steering angle signal. Steering cycle calculating means, and comparing means for comparing the corrected steering cycle and a reference cycle,
Wherein the steering cycle calculation means comprises: a delay means for delaying the detected steering angle signal for a predetermined time; a difference means for calculating a difference between the detected steering angle signal and a delay signal from the delay means; A drowsy driving detection device, comprising: detection means for detecting a zero point from a change in the sign of the difference output from the difference means. 2. The drowsy driving detection device according to claim 1, wherein the detection unit detects a change in the sign using a predetermined positive threshold value and a predetermined negative threshold value that are set across a zero point of the difference output. A dozing driving detection device characterized by detecting. 3. The drowsy driving detection device according to claim 1, wherein the detection unit uses an absolute value of the difference output. 4. The method according to claim 1, 2 or 3.
The drowsy driving detection device according to claim 1, wherein the delay unit reduces the delay time when the vehicle is traveling on a curved road. 5. The method according to claim 1, 2 or 3.
The drowsy driving detection device according to claim 1, wherein the delay unit changes the delay time in accordance with a value of the difference output. 6. The drowsy driving detection device according to claim 5, further comprising: integration means for calculating respective integral values of the positive output and the negative output of the difference output; and an integral value for comparing the positive integral value and the negative integral value. A drowsiness detection device, comprising: a comparison unit; and wherein the delay unit changes the delay time according to a comparison result from the integration value comparison unit. 7. The drowsy driving detection device according to claim 2, further comprising: integration means for calculating an integral value of each of the positive output and the negative output of the difference output; and an integral value for comparing the positive integral value and the negative integral value. A drowsing driving detecting device, comprising: comparing means; and wherein the detecting means changes the positive threshold value and the negative threshold value according to a comparison result from the integral value comparing means. 8. The method according to claim 1, 2 or 3.
The drowsy driving detection device according to claim 1, further comprising: gain control means for changing an amplification gain of the steering angle signal when the vehicle is traveling on a curved road. 9. The method of claim 1 or claim 2 or claim 3.
The drowsy driving detection device according to claim 1, wherein the comparison unit changes the reference cycle when the vehicle is traveling on a curved road. 10. The drowsy driving detection device according to claim 8, further comprising: integration means for calculating an integral value of each of a positive output and a negative output of the differential output; A drowsy driving detection device, comprising: integrated value comparing means for comparing; and detecting a curved lane based on a comparison result by the integrated value comparing means.