JPH07195956A - Doze driving detection device - Google Patents

Abstract

(57) [Abstract] [Purpose] A doze driving detection device that detects a driver's correction steering cycle to detect a decrease in consciousness accurately detects the correction steering cycle. A steering angle signal from a steering angle sensor is output to a corrected steering cycle measuring unit 12. The delay circuit 12a of the corrected steering cycle measuring unit 12 delays the steering angle signal by a predetermined time and outputs it to the difference circuit 12b. The difference circuit 12b calculates the difference between the steering angle signal and its delay signal and outputs the difference to the threshold circuit 12c. The threshold circuit 12c detects the zero level of the differential output using a predetermined threshold value near the zero level,
The dozing state is determined by comparison with the reference cycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drowsy driving detection device, and more particularly to a device 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 installed for the purpose of improving the safety of vehicle running, and one of them is a drowsiness detection device that detects drowsiness of a driver and issues an alarm. .

As a method for detecting a drowsy driving, there are a method of taking a face image of a driver, a method of measuring a driver's pulse, and a method of detecting a steering state of a vehicle. For example, Japanese Unexamined Patent Publication No. 60-76424 discloses that the drowsiness is detected when the steering wheel is turned by a certain angle, and Japanese Unexamined Patent Publication No. 60-157927 discloses a steering operation within a predetermined time. It is shown that the dozing driving is detected because the high frequency component of the angle change is equal to or more than a predetermined value.

However, in these conventional techniques, there is a problem that the curve traveling is erroneously detected as a drowsy driving, and the high-frequency component is generated other than during the drowsy driving.

Therefore, the applicant of the present application paid attention to the fact that there is a correlation between the driver's consciousness level and the corrected steering period, and previously calculated the corrected steering period in Japanese Patent Application No. 4-2544694, We propose a configuration that detects drowsy driving compared to the normal period (reference period).

[0006]

However, it is not always easy to calculate the correction steering cycle from the detected steering angle data. For example, it is conceivable to differentiate the obtained steering angle signal with time and use the point where it becomes zero as the correction steering, but steering vibration due to the reaction force from the road surface and the slight turning back of the driver are also used as the correction steering point at the same time. It may be detected. In such a case, the correction steering cycle is generally shortened, and there is a possibility that the dozing driving cannot be detected even in the dozing state.

The present invention has been made in view of the above problems of the prior art, and its purpose is to reliably detect the corrected steering point from the obtained steering angle signal to accurately detect the corrected steering cycle of the driver. An object of the present invention is to provide a drowsy driving detection device capable of detecting drowsiness by using this modified steering cycle.

[0008]

In order to achieve the above object, a drowsy driving detection device according to claim 1 is a drowsy driving detection device for detecting a drowsiness of a driver from the running state of the vehicle. Steering angle detecting means for detecting the steering angle,
The steering cycle calculating means includes 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. Delay means for delaying the signal for a predetermined time,
It has 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, the drowsiness driving detection apparatus according to a second aspect of the present invention is the drowsiness driving detection apparatus according to the first aspect, wherein the detection means is set with the zero point of the differential output interposed therebetween. It is characterized in that the change of the sign is detected by using the predetermined positive and negative threshold values.

In order to achieve the above object, the drowsiness driving detection device according to claim 3 is the drowsiness driving detection device according to claim 1 or 2, wherein the detection means is an absolute value of the difference output. Is used.

In order to achieve the above object, the drowsiness driving detection device according to claim 4 is the dozing driving detection device according to any one of claims 1 or 2 or 3.
The delay means reduces the delay time when the vehicle is traveling on a curved road.

In order to achieve the above object, the drowsiness driving detection device according to claim 5 is the dozing driving detection device according to claim 1, 2 or 3, wherein the delay means is The delay time is changed according to the value of the differential output.

Further, in order to achieve the above object, the drowsiness driving detection apparatus according to a sixth aspect is the same as the drowsiness driving detection apparatus according to the fifth aspect, further comprising integrated values of the positive output and the negative output of the differential output. And an integration value comparison means for comparing a positive integration value and a negative integration value, wherein the delay means changes the delay time according to a comparison result from the integration value comparison means. And

Further, in order to achieve the above object, the drowsy driving detection device according to claim 7 is the same as the drowsiness driving detection device according to claim 2, further comprising an integrated value of each of the positive output and the 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 has the positive threshold value and the negative threshold value according to the comparison result from the integral value comparing means. It is characterized by changing.

In order to achieve the above object, the drowsy driving detection device according to claim 8 is the dozing driving detection device according to claim 1, 2 or 3.
Further, it is characterized by further comprising gain control means for changing an amplification gain of the steering angle signal when the vehicle is traveling on a curved road.

Further, in order to achieve the above object, the drowsy driving detection device according to claim 9 is the dozing driving detection device according to claim 1, claim 2 or claim 3.
The comparison means changes the reference period when the vehicle is traveling on a curved road.

Further, in order to achieve the above object, the drowsiness driving detection device according to claim 10 is the same as the drowsiness driving detection device according to claim 8 or 9, further comprising positive and negative outputs of the differential output. Integrating means for calculating respective integral values and integral value comparing means for comparing positive and negative integral values are provided, and the curve running path is detected based on the comparison result by the integral value comparing means. .

[0018]

In the drowsy driving detection device according to the first and second aspects, the steering angle signal is delayed by a predetermined time, and the difference between the steering angle signal and this delay signal is calculated. Generally, the corrected steering point appears as the top (maximum) and bottom (minimum) points of the steering angle signal. Therefore, by performing the difference calculation, a zero point occurs in the difference output when the top or the bottom occurs. Then, this zero point is none other than the top or bottom timing information of the steering angle signal and indicates the corrected steering cycle.

The zero point of the differential output can be detected from the change in the sign of the differential output. This is because there is a zero point because there is a change in the sign. 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 turning back such as a steering reaction force from being detected as a zero point, and it is possible to accurately detect the corrected steering cycle.

In the dozing driving detection device according to claim 3,
The zero point of the differential output is detected by comparing the absolute value of the differential 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.

In the drowsiness driving detection device according to claims 4 and 5, the delay time for generating the delay signal is changed according to the running path. When the vehicle is traveling on a curved road, the driver task is heavily loaded and the steering amount changes frequently. Therefore, even with the same delay time, the value of the differential output increases on the curved track as compared to the straight track. As described above, since the differential output becomes large on the curve runway, the zero point detection by the detecting means is incorrect. Therefore, the delay time is reduced on the curve runway and the differential output value is maintained within a certain range.

In the drowsiness driving detection device according to claims 6 and 7, the positive and negative integral values of the difference output are calculated,
These magnitudes are compared. When the vehicle is traveling on a curved road, a left / right deviation also occurs in the steering angle signal, and thus a difference output also has a positive / negative deviation due to the left / right deviation. Therefore, by comparing the magnitudes of the positive and negative integral values, it is possible to determine whether the vehicle is traveling on a curved road, further on a right curved road, or on a left curved road. You can When the difference output has positive or negative deviation, 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 made 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.

In the dozing driving detection device according to claim 8,
Since the differential output increases on the curved road as described above, the amplification gain of the steering angle signal is reduced to keep the differential output value within a certain range.

In the dozing driving detection device according to claim 9,
The driver task is heavily burdened on the curved road, and the correction steering cycle tends to be shortened. Therefore, on the curved road, the drowsiness state of the driver can be reliably detected by setting a short reference cycle for determining the driver's deterioration of consciousness.

In the doze driving detection apparatus according to the tenth aspect, the curve running path is detected by comparing the magnitude of the positive integral value and the negative integral value. As described above, when the vehicle is traveling on a curved road, the steering angle signal also has a left / right deviation, and therefore a difference output also has a positive / negative deviation due to the left / right deviation. Therefore, by comparing the magnitudes of the positive and negative integral values, 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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the dozing driving detection device of the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 shows the overall construction of a doze driving detection apparatus of 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 the steering angle. The detected steering angle signal is output to the corrected steering cycle measuring unit 12. The modified steering cycle measuring unit 12 performs the processing described below to extract the modified steering point and measures the cycle. The measured corrected steering cycle is output to the consciousness deterioration determination unit 14. The consciousness lowering determination unit 14 compares the reference period during normal driving with the measured corrected steering period, and when it becomes longer than the reference period, it is determined that the driver's consciousness is lowered,
An alarm activation signal is output to the alarm unit 16. The alarm unit 16 issues an alarm based on the alarm activation signal to call the driver's attention. Although not shown, it is also possible to adopt a configuration in which a control signal is output from the lowering of consciousness determination unit 14 to a brake actuator or the like to automatically perform deceleration control when it is determined that the driver's lowering of consciousness is determined. .

FIG. 2 shows the configuration of the corrected steering cycle measuring section 12 in this embodiment. The modified steering cycle measuring unit 12 in the present embodiment delays the steering angle signal output from the steering angle sensor 10 by a predetermined time, a difference circuit 12b for calculating a difference between the steering angle signal and the delay signal, and a predetermined operation. It is composed of a threshold circuit 12c for detecting the zero point of the differential signal using the threshold value. The delay time in the delay circuit 12a is set to, for example, 0.2 sec, and the steering angle signal is delayed by a predetermined time to delay the difference circuit 12b.
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 the 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 the delay time.

On the other hand, FIG. 4 shows an example of the difference output output from the difference circuit 12b to the threshold circuit 12c. In the figure, the horizontal axis represents the time t and the vertical axis represents the difference output. Further, a solid line indicated by reference numeral 104 indicates a difference signal, a two-dot chain line 500 indicates a positive side predetermined threshold level, and a two-dot chain line 502 indicates a negative side predetermined threshold level. There is. The threshold circuit 12c uses these positive and negative threshold values to convert the differential signal into a pulse signal. At this time, the threshold circuit 12c converts into a pulse signal due to the hysteresis characteristic. That is, when the pulse signal falls from the positive side to the negative side threshold level 502 or less, the pulse falls, while when the difference signal rises from the negative side to the positive side threshold level 500 or more, the pulse signal 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 a hysteresis characteristic. In FIG. 5, the horizontal axis represents time t,
The vertical axis represents 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 the bottom, a zero point occurs in the differential output between the steering angle signal and its delay signal, and this zero point is the top or bottom of the steering angle signal. 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 modified steering point.

Here, even if the steering angle signal includes a weak turning-back due to the steering reaction force caused by the road surface unevenness or the like, the difference signal indicates a zero point as shown by A in FIG. Therefore, if the zero point is detected by the threshold value circuit 12c having the above-mentioned hysteresis characteristic, the correction steering cycle can be reliably measured without erroneously detecting the weak turning back as the correction steering point.

Second Embodiment FIG. 6 shows the configuration of the corrected steering cycle measuring section 12 in the embodiment. The corrected steering cycle measuring unit 12 of this embodiment is composed of a delay circuit 12a, a difference absolute value 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 it to the difference absolute value circuit 12d, as in the delay circuit in the first embodiment. The difference absolute value circuit 12d calculates the difference between the steering angle signal and the delay signal, and further outputs the magnitude (that is, absolute value) to the threshold value circuit 12c. The threshold value circuit 12c compares the difference output from the absolute difference value circuit 12d with a predetermined threshold value and outputs a pulse signal.

FIG. 7 shows the differential 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 the difference output.
Further, the solid line 106 shows the difference output, and the chain double-dashed line 504 shows the threshold level. By generating the pulse signal when the differential output becomes equal to or lower than the threshold level 504 near zero, a pulse waveform as shown in FIG. 8 is obtained. Then, similarly to the first embodiment described above, the rising or falling of this pulse waveform represents the zero point of the differential signal, that is, the corrected steering point.

Also in the present embodiment, the weak turning back such as the steering reaction force is not detected as the correction steering point by properly setting the threshold level 504, and the correct correction steering cycle can be detected. It is needless to say that in the present embodiment as well, the influence of the disturbance can be more surely 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 corrected steering cycle measuring section 12 of this embodiment. The corrected steering cycle measuring section in this 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 delayed signal to calculate the difference between the threshold value circuit 12c.
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 differential 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 variation in the steering angle is larger than that when the vehicle is traveling on a straight road, and therefore the differential output from the differential circuit 12b is the same for the same delay time. growing. Therefore,
When the threshold circuit 12c sets the same threshold level, 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 adjusted to be increased or decreased. As the adjustment method, the difference circuit 12b is used.
If the difference output from is large, reduce the delay time,
When the difference output is small, the delay time in the delay circuit 12a is set large. FIG. 10 shows a 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 the delay signal when traveling on a curved road.

As described above, in this embodiment, a part of the differential signal from the differential circuit 12b is fed back to the delay circuit 12a and the delay time of the delay circuit 12a is feedback-controlled, so that the threshold circuit 12c is used. The differential output input to is within a certain fixed range, and the corrected steering cycle can be accurately measured using the same threshold value.

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

The delay circuit 12a and the difference circuit 12b in this embodiment perform the same operation as in the first embodiment described above, 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. This FIG. 12 corresponds to FIG. 3 described above. Difference circuit 1
2b calculates the difference between the steering angle signal 102 and the delay signal 104, and outputs the 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 the difference signal. The delay time is 0.2 sec as in the first embodiment.

Then, 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 which are sequentially output from the integrator 12e to the comparator 12f. The comparator 12f compares the positive integration output and the negative integration output as described above, and outputs the 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 the positive and negative continuous time intervals and the final integrated value thereof as respective values, and outputs them to the threshold circuit 12c. The threshold circuit 12c changes the threshold value on the positive side and the threshold value on the negative side by a value obtained by multiplying the comparison output value output from the comparator 12f by a predetermined coefficient. Specifically, the threshold circuit 12
In c, control is performed to increase the threshold value of the larger comparison output value. When the vehicle is traveling on a curved road, a left-right deviation is generated in the steering angle signal, so that a difference occurs between the positive integration value and the negative integration value from the integrator 12e. Therefore, the comparison output value from the comparator 12f means that the steering angle signal has a left-right deviation, that is, the vehicle is currently traveling on a curved road. By changing the level in accordance with the left-right deviation of the steering angle signal, it is possible to accurately measure the corrected steering cycle.

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

Fifth Embodiment FIG. 15 shows the configuration of the corrected steering cycle measuring section 12 of this embodiment. Also in this embodiment, similarly to the fourth embodiment described above, the delay circuit 12a, the difference circuit 12b, the threshold circuit 12c, the integrator 12e, and the comparator 12f are provided, but in this embodiment, 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, so that the vehicle is currently traveling on a curved road. That is, the comparator 12
When the comparison output value from f is a certain value or more, the delay time in the delay circuit 12a can be set to be small and the level of the difference signal output from the difference circuit 12b can be suppressed within a certain range. Becomes This makes it easier to detect the zero point in the threshold circuit 12c, and enables accurate measurement of the corrected steering cycle.

Sixth Embodiment FIG. 16 shows the configuration of the sixth embodiment of the present invention.
The corrected steering cycle measuring unit 12 in this embodiment has a delay circuit 12a and a difference circuit 12 as in the above-described fourth and fifth embodiments.
b, threshold circuit 12c, integrator 12e, and comparator 1
It is composed of 2f. Then, in the present embodiment, a part of the comparison output from the comparator 12f is output to the consciousness lowering determination unit 14, and the reference cycle in the lowering consciousness determination unit 14 is adjusted to be 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 load on the driver task, and the shorter the correction steering cycle tends to be. Therefore, when traveling on a curved road, it is necessary to set the reference period in the normal condition, which is a reference for determination of lowering of consciousness, to be shorter than that when traveling on a straight road. Therefore, in the present embodiment, the comparison output from the comparator 12f, which indicates 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 reference period is set shorter as the comparison output value from the comparator 12f increases. As a result, even when the vehicle is traveling on a curved road, it is possible to detect the deterioration of the driver's consciousness with the same accuracy as when traveling on a straight road.

In this embodiment, the comparison output from the comparator 12f is supplied to the delay circuit 12a, the threshold circuit 12c,
Although the configuration for outputting to the consciousness deterioration determination unit 14 is shown, the configuration is such that the comparison output from the comparator 12f is output to the 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 the configuration in which the gain of the amplifier is increased or decreased by the comparison output value. The corrected steering cycle measuring unit 12 in this embodiment is also the delay circuit 12a, the difference circuit 12b, and the threshold circuit 1 as in the above-described embodiments.
2c, an integrator 12e, and a comparator 12f, but in the present embodiment, a part of the output from the comparator 12f is an amplifier 1 provided in the subsequent stage of the steering angle sensor 10.
1 and the amplification factor is adjusted up or down based on the output of the comparator 12f.

On the curve runway, the difference output value increases as described above, which makes it difficult to make a decision by the threshold circuit. Therefore, when the comparison output value from the comparator 12f is a certain value or more, the amplification factor in the amplifier 11 can be reduced and the level of the difference signal output from the difference circuit 12b can be suppressed within a certain range. . The degree of decrease may be decreased linearly according to the comparison output value, or may be decreased in an arbitrary functional relationship. This allows
Threshold circuit 12c, regardless of the curve radius of the curved track
This makes it easier to detect the zero point at, and enables accurate measurement of the corrected steering period.

In FIG. 17, the output of the comparator 12f is also supplied to the threshold circuit 12c so that both the amplification factor and the threshold can be adjusted. Although it is sufficient to increase or decrease the amplification rate,
By mutually adjusting each parameter of the system in this manner, it becomes 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 the respective parameters are mutually adjusted.

[0050]

As described above, according to the drowsy driving detection device of the first to the tenth aspects, the corrected steering cycle can be detected stably and accurately, whereby the drowsy state of the driver is obtained. 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 drawings]

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

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

FIG. 3 is an explanatory diagram of a steering angle signal and its delayed signal in the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of differential output according to the first embodiment of this invention.

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

FIG. 6 is a configuration block diagram of a modified steering cycle measurement unit in the second embodiment of the present invention.

FIG. 7 is an explanatory diagram of differential output according to the second embodiment of the present invention.

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

FIG. 9 is a configuration block diagram of a modified steering cycle measurement unit in the third embodiment of the present invention.

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

FIG. 11 is a configuration block diagram of a modified steering cycle measurement unit in the third embodiment of the present invention.

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

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

FIG. 14 is an output explanatory diagram of an integrator in the fourth example of the present invention.

FIG. 15 is a configuration block diagram of a modified steering cycle measurement unit in a fifth embodiment of the present invention.

FIG. 16 is a configuration block diagram of a modified steering cycle and consciousness deterioration determination unit according to a sixth embodiment of the present invention.

FIG. 17 is a configuration block diagram of a modified steering cycle and consciousness deterioration determination unit according to a seventh embodiment of the present invention.

[Explanation of symbols]

 10 Steering Angle Sensor 11 Amplifier 12 Corrected Steering Cycle Measurement Section 14 Consciousness Deterioration Determination Section 16 Alarm Section

Claims (10)

[Claims] 1. A drowsy driving detection device for detecting a driver's dozing from the running state of a vehicle, the steering angle detecting means for detecting a steering angle of the vehicle, and a corrected steering cycle calculated from the detected steering angle signal. Steering cycle calculating means, and comparing means for comparing the corrected steering cycle with a reference cycle,
The steering cycle calculating means includes delay means for delaying the detected steering angle signal by a predetermined time, difference means for calculating a difference between the detected steering angle signal and the delay signal from the delay means, and And a detection unit that detects a zero point from a change in the sign of the difference output from the difference unit. 2. The dozing driving detection device according to claim 1, wherein the detection means uses a predetermined positive threshold value and a negative threshold value set with a zero point of the difference output interposed therebetween to detect a change in sign. A dozing driving detection device characterized by detecting. 3. The dozing driving detection device according to claim 1, wherein the detection means uses an absolute value of the difference output. 4. Claim 1 or claim 2 or claim 3.
In the drowsy driving detection device described above, the delay means reduces the delay time when the vehicle is traveling on a curved road, the drowsiness driving detection device. 5. Claim 1 or claim 2 or claim 3.
In the drowsy driving detection device described above, the delay means changes the delay time in accordance with the value of the difference output. 6. The drowsiness driving detection device according to claim 5, further comprising: an integrating means for calculating an integral value of each of the positive output and the negative output of the differential output, and an integral value for comparing the positive integral value and the negative integral value. A drowsing driving detection device comprising: a comparison unit, wherein the delay unit changes the delay time according to a comparison result from the integral value comparison unit. 7. The drowsiness driving detection device according to claim 2, further comprising an integrating means for calculating an integral value of each of the positive output and the negative output of the differential output, and an integral value for comparing the positive integral value and the negative integral value. Comparing means, wherein the detecting means changes the positive threshold value and the negative threshold value according to the comparison result from the integral value comparing means. 8. Claim 1 or claim 2 or claim 3.
The drowsy driving detection device according to claim 1, further comprising: a gain control unit that changes an amplification gain of the steering angle signal when the vehicle is traveling on a curved road. 9. Claim 1 or claim 2 or claim 3.
The drowsy driving detection device as described above, wherein the comparing means changes the reference period when the vehicle is traveling on a curved road. 10. The doze driving detection apparatus according to claim 8 or 9, further comprising an integrating means for calculating an integral value of each of the positive output and the negative output of the differential output, and a positive integral value and a negative integral value. An integration value comparison means for comparing, and a drowsy driving detection device characterized by detecting a curve running path based on a comparison result by the integration value comparison means.