JP2817559B2 - Arousal level determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wakefulness judgment apparatus for judging the wakefulness of a human being, such as a driver of a vehicle, a ship or an airplane.

[0002]

2. Description of the Related Art In recent years, the remarkable development of the road network has greatly improved the moving ability of automobiles, thereby increasing the radius of action, and the stability of life and the increase of leisure have strengthened the leisure orientation of families. The opportunity to drive a car in daily life is increasing. The driver always desires stable mental and physical health when driving this car, but generally, in most cases, the driver tends to grasp the steering wheel while ignoring the poor physical condition. It is desirable to drive a car within an appropriate range appropriate for one's own physical condition, but in some cases, one's own physical condition can be overwhelmed without being noticed. If the vehicle is driven continuously without a long rest, fatigue builds up in the driver, deteriorating the state of health, and increasing the possibility of causing an accident due to reduced concentration.

For this reason, conventionally, a drowsy driving warning device is provided in a vehicle, a signal for requesting a response is given to a driver at a certain time interval, and a warning is given by judging a decrease in arousal level based on the appropriateness of the response time of the driver. There is something that I did. But,
In this conventional device, a response may be required when the driver has to concentrate his or her nerves, such as when driving in a city area or on a curve, or when the arousal level has not decreased, which is troublesome for the driver. won.

[0004] Therefore, it has been considered to prevent an accident by monitoring the driving condition based on one's own physical condition and notifying the driver when the driving condition exceeds an appropriate driving limit. It is disclosed in the gazette. In general, it is known that the heart rate of a human heart increases or decreases according to driving intensity, mental tension, or fear. Therefore, in the arousal level determination device disclosed in this publication, the sensor detects the heart rate of the driver who is driving the vehicle, sequentially calculates and converts the cycle of the heart rate, and the numerical value is within an allowable range. The arousal level of the driver is determined by determining whether the vehicle is within the vehicle.

[0005]

In the above-described conventional arousal level determination apparatus, the heart rate of the driver who is driving is detected by a heart rate sensor (photocoupler), and based on the detected heart rate data. To determine the degree of awakening of the driver. This heart rate sensor is provided on the steering wheel, and is generated from the light emitting diode when the driver's right thumb touches the surface of the insulating substrate so as to cover the light emitting surface of the light emitting diode and the light receiving surface of the phototransistor. Light is reflected by blood passing through blood vessels in the thumb and enters the phototransistor, and a light reception signal is generated at a level corresponding to the amount of incidence, thereby detecting the driver's pulse wave.

[0006] If the vehicle is driven for a long time without a break, fatigue is accumulated in the driver, the concentration is reduced, and the awakening degree is also reduced.
Sleeping may occur, and you will eventually fall asleep. In the conventional arousal level determination device, when detecting a driver's heart rate, the driver must hold a predetermined position of a steering wheel and put his right thumb on a heart rate sensor (photocoupler). . However, when the driver falls asleep, the driver loses his / her grip on the steering wheel and also releases his / her hand from the steering wheel, making it impossible to grip a predetermined position of the steering wheel. Therefore, the heart rate sensor cannot detect the driver's heart rate, and may not be able to determine the driver's arousal level.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a waking degree determining apparatus which can accurately determine a waking degree of a driver even when the driver is in a similar state. Aim.

[0008]

According to a first aspect of the present invention, there is provided a waking degree determining apparatus for detecting a steering angle of a running vehicle. Calculates the frequency distribution of the steering angle signal so that the driver can see
Steering angle data processing means for obtaining a driver's steering characteristic parameter by extracting a visual steering component performing steering based on information; and presetting the steering characteristic parameter obtained by the steering angle data processing means Arousal level determination means for determining a reduction in the level of arousal level in comparison with the reference value.

[0009]

SUMMARY OF steering angle sensor detects the steering angle of the vehicle during traveling, the steering angle data processing means calculates a frequency distribution of steering angle signal based on the output of the steering angle sensor, the driver visual
The parameters of the driver's steering characteristics are obtained by extracting a visual steering component that is performing steering based on the tactile information ,
The arousal level determination means compares the parameter of the steering characteristic with a preset reference value to determine a decrease in the arousal level.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic structure of a drowsiness alarm device for a vehicle having an awakening degree determination device according to an embodiment of the present invention. FIG. 2 is a perspective view showing an exterior of a vehicle cabin in this embodiment. A graph showing the change over time of the arousal level of the driver,
FIG. 4 is a conceptual diagram showing a relationship between a heartbeat pulse from a heartbeat sensor and heart rate data calculated by the heartbeat processing means, and FIGS. 5 to 7 are flowcharts showing a flow of processing by the heartbeat processing means of this embodiment. FIG. 8 is a flowchart showing the flow of processing by the heart rate data processing means of the present embodiment, and FIGS.
1 is a flowchart showing the flow of processing by the heart rate arousal degree determining means of the present embodiment, FIG. 12 is an extracted enlarged cross section of a portion of a steering shaft to which a steering angle sensor is attached, and FIG. FIG. 14 is a graph showing a visual steering component of a driver, FIG. 14 is a graph showing a frequency distribution of a steering angle of a steering wheel when upper visibility is restricted to the driver, and FIG. 15 is a schematic diagram showing an upper visibility restricted area of a vehicle driver. ,
FIGS. 16 and 17 are flowcharts showing the flow of processing by the steering angle data processing means of the present embodiment, FIGS.
9 is a flow chart showing the flow of processing by the steering arousal degree determination means of this embodiment, FIGS. 20 and 21 are flow charts showing the flow of alarm processing by the alarm control means of this embodiment, and FIG. 22 is a handle grip of this embodiment. FIG. 23 is a flowchart showing the flow of processing by the failure alarm processing unit, and FIG. 23 is a flowchart showing the flow of processing by the reference value correction unit of this embodiment.

As shown in FIGS. 1 and 2, a pair of left and right infrared heart rate sensors 11 and 12 for detecting a driver's heart rate pulse (not shown) receive detection signals from the infrared heart rate sensors 11 and 12, respectively. The heart rate processing means 13 and 14 for receiving and calculating the heart rate of the driver are connected to the heart rate processing means 13 and 14.
4 is connected to a signal selection means 15 which adopts a more preferable output signal among the output signals from the output signal 4. Also, a potential type heart rate sensor 1 different from the heart rate sensors 11 and 12 described above.
6 is connected to a heart rate processing means 17 which receives a detection signal from the potential type heart rate sensor 16 and calculates the driver's heart rate. The signal selection means 15 and the heart rate processing means 17
Is connected to a heart rate data processing means 18 for calculating the average value of the heart rate and its change state based on the output signals from the signal selection means 15 and the heart rate processing means 17. The heart rate data processing means 1
8 is connected to a heartbeat alertness determining means 19 for determining the alertness of the driver based on the calculation result from Step 8.

On the other hand, a steering angle sensor 21 for detecting a deviation of the steering shaft 20 from a neutral position (hereinafter, referred to as a steering angle) receives a detection signal from the steering angle sensor 21 and performs frequency analysis. A steering angle data processing means 22 for calculating a parameter of the steering component is connected, and the steering angle data processing means 22 is connected to the steering angle data processing means 22.
Is connected to the steering arousal level determination means 23 for determining the arousal level of the driver based on the calculation result from. The steering angle data processing means 22 in this embodiment is also connected to a vehicle speed sensor 24 for detecting the running speed of the vehicle (hereinafter, referred to as the vehicle speed). The data is taken into the data processing means 22.

Further, the vehicle of this embodiment has a tactile alarm means 26 for issuing a drowsiness alarm by deformation of the driver's seat 25, a visual alarm means 28 for transparently displaying a drowsiness alarm on a front window 27 of the vehicle, and a drowsiness alarm sound. And an audible alarm means 29 that emits light.
Alarm control means 30 for controlling the operation of 6, 28, 29 includes:
The heartbeat arousal level determining means 19 and the steering arousal level determining means 2
The alarm level selected by the heartbeat arousal level determining means 19 and the steering arousal level determining means 23 and data relating to the driver's arousal level are output to the alarm control means 30. Arousal level determination means 19
The operation of the above three alarm means 26, 28, 29 is controlled on the basis of the alarm level selected by the steering alertness determination means 23.

Further, an alarm release switch 31 is provided in the passenger compartment for the driver to release the above-mentioned alarms caused by the operation of the three alarm means 26, 28 and 29. The alarm control unit 30 and the reference value correction unit 32 are connected. The reference value correction unit 32 is connected to the heart rate arousal level determination unit 19 and the steering arousal level determination unit 23, respectively, and the data calculated by the reference value correction unit 32 is used for the heart rate arousal level determination unit 1.
9 and the steering arousal level determination means 23.

In the present embodiment, the two types of heart rate sensors 11, 12, and 16 described above are attached to predetermined positions of the steering wheel 33, respectively. Otherwise, the potential-type heart rate sensor 16 cannot detect the heart rate pulse, so a mechanism for urging the driver to correctly grip the steering wheel 33 is also incorporated.

That is, the alarm control means 3 is provided in the vehicle of this embodiment.
A handle grip failure alarm means 34 whose operation is controlled by 0 is provided. In this embodiment, two of the above three alarm means 26 and 29 are used as the handle grip failure alarm means 34 in this embodiment. I have. The alarm control means 30 includes the heartbeat processing means 13, 14, 17.
A poor handle grip warning processing unit 35 that receives the output signal from the steering wheel as it is is incorporated. It is determined whether or not the driver is gripping the steering wheel 33 correctly, and if it is determined that the driver is not gripping the steering wheel 33 correctly, the steering wheel grip failure alarm means 34 is activated while If it is determined that there is, the operation of the poor handle grip warning means 34 is automatically stopped.

It is well known that the awakening degree of a driver generally tends to gradually decrease immediately after boarding, but it is necessary to drive for a long time on a monotonous road in a suburb without congestion or on a motorway. In many cases, there is a noticeable decrease. FIG. 3 is a graph showing an example of such a temporal change in the arousal level of the driver. That is, the area represents the area until the driver gets into the vehicle by walking or the like, represents the area where the degree of arousal is reduced by sitting on the driver's seat 25, and represents the area where the degree of arousal is increased immediately after the start of traveling and in the city area, etc. The area represents a region where the awakening level is stable when traveling on a monotonous road or a motorway that is not crowded, and the area represents a conflict area where the driver's awakening level goes up and down and sleeps. It represents an area where the arousal level has fallen and the user has fallen asleep.

As is apparent from FIG. 3, usually, before the area where the driver enters a dozing state, there is an area where the arousal level rises and falls and a conflict with the sleep occurs. It is common that there is a region where the awakening degree of the driver is stabilized before the conflict state. In other words, the degree of awakening of the driver is continuously monitored to estimate a stable area of the degree of awakening, and from this stable area of the degree of awakening, a conflict area with a drowsy in which the degree of awakening of the driver rises and falls relatively large is predicted. By issuing an alarm here, it is possible to prevent the driver from falling asleep.

Based on such knowledge, the change in arousal level shown in FIG.
, Based on the detection signal, the two types of heart rate sensors 11, 12, 16 in the present embodiment.
Are incorporated at predetermined positions of the steering wheel 33.

The infrared type heart rate sensors 11 and 12, which function independently of each other, utilize the reflection of infrared light by hemoglobin in blood pulsating in a blood vessel with the heartbeat, and periodically reflect the heartbeat. Light-emitting units 11a and 11 that project infrared light to detect the amount of reflected infrared light that changes.
2a and light receiving portions 11b and 12b for receiving the infrared rays constitute a main portion, which are assembled on the left and right sides of the steering handle 33, respectively. Since it is already well-known, further detailed description is omitted.

The potential-type heart rate sensor 16 uses a pair of electrodes 16a and 16b attached to the steering wheel 33 as a pulse-like voltage generated at the time of myocardial contraction as a pulse-like potential difference generated between both hands of the driver. The structure and the like are already known in JP-A-59-25729, etc., and therefore, further detailed description will be omitted.

The infrared type heart rate sensor 11,
12 may malfunction if strong sunlight or the like hits the steering wheel 33.
If the driver does not hold the steering wheel 33 correctly with both hands, the heart rate cannot be detected. Therefore, in this embodiment, these two types of heart rate sensors 11, 12, and 16 are used as described below. Consideration is given to ensure that the driver's heart rate can be reliably detected in combination.

The heart rate processing means 13 and 14 calculate the driver's heart rate based on the detection signals from the infrared type heart rate sensors 11 and 12, and similarly, the heart rate processing means 17 comprises a potential type heart rate sensor. The heart rate of the driver is calculated based on the detection signal from the heart rate sensor 16. The calculation contents of the heartbeat processing means 13, 14, and 17 are basically exactly the same, and correction of an abnormal detection signal is appropriately performed to obtain an interval between heartbeat pulses (hereinafter referred to as a pulse interval) and the pulse interval. The heart rate corresponding to the interval is calculated.

The heartbeat processing means 13, 14, 17
Calculated heart rate data and detected by heart rate sensor
As shown in FIG. 4, which shows an example of the relationship with the heartbeat pulse,
For example, the pulse interval is longer than the previously measured pulse interval
If it suddenly becomes shorter, it will be based on the pulse interval at this time.
The calculation of the heart rate is temporarily suspended, and the next measured
The sum of the pulse interval and the previous pulse interval is the previous pulse
If the interval is almost the same, the previous heart rate pulse information is abnormal.
And cancel the previous heart rate data
You. For example, time t_{P (n-4)}And the time t following it_{P (n-3)}
Pulse interval I _{P (n-4)}, I_{P (n-3)}Is the previous
Loose interval I_PIf it is abnormally shorter than _{P (n-4)}At
The calculated heart rate is suspended and these two pulse intervals I
_{P (n-4)}, I_{P (n -3)}Is the pulse interval up to that point
I_PIf it is almost equal to the time t_{P (n- Four)}Heart pal in
At the time t_{P (n-4)}Heart in
Cancel the beat count data. Also, the pulse interval is suddenly long
If it becomes longer, the next measured pulse interval is
If the pulse interval is almost the same as
Half of the time is added to the time at which the pulse interval was calculated two times before.
Then, the heart rate data at this time is interpolated. For example,
Time t_{P (n-1)}Pulse interval I_{P (n-1)}But before that
Pulse interval I_PIf it is abnormally longer than the next heartbeat pulse
Is detected at time t_{P (n)}Pulse interval I_{P (n)}Was earlier
Pulse interval I_PApproximately the same between the previous and previous times
Judging that the normal heartbeat pulse could not be detected,
Pulse interval I_{P ( n-1)}Half the time before the heartbeat pulse
Is detected at time t_{P (n-2)}To the heart rate at this point
Is calculated.

FIGS. 5 to 7 show the flow of the processing in the heartbeat processing means 13, 14, 17 as described above. That is, the processing of the heart rate processing means 13, 14, 17 in the present embodiment is performed at a predetermined cycle, for example, every interruption signal every 15 milliseconds.
The detection time t _P of the heartbeat pulse, which is the detection signal from the CPU, is read, and the detection time t of the current pulse is read in step a2.
_The current pulse interval _{IP (n)} is calculated based on the following equation by subtracting the previous pulse detection time tP _(n-1) from _{P (n)} . _{IP (n)} = tP _(n) -tp _(n-1)

[0027] Then, it is determined whether the pulse interval reference value I _PB is set at a3 step, initially the pulse interval reference value I _PB is not set, the process proceeds to step a4 It is determined whether the pulse interval I _{P (n)} is between a preset minimum pulse interval I _MN , for example, 600 ms, and a maximum pulse interval I _MX , for example, 1200 ms.

In the step a4, the pulse interval I _{P (n)}
Is not between the minimum pulse interval I _MN and the maximum pulse interval I _MX , that is, the pulse interval I calculated in step a2
_When it is determined that _{P (n)} is abnormal, the process returns to step a1 after the above-described interrupt signal of the predetermined cycle. In step a4, the pulse interval I _{P (n)} is between the minimum pulse interval I _MN and the maximum pulse interval I _MX .
That pulse is calculated in step a2 interval I _{P (n)} if it is determined that the normal value at the calculated step pulse interval I _P a _(n) a5 in step a2 reference pulse is adopted as the interval I _PB, the reference pulse interval I _PB and preset additional time T _a at a6 step, for example, than the sum of the 250 msec time pulse interval I _{P (n)}
Is determined to be long. If it is determined in step a3 that the reference pulse interval I _PB has been set, the process also proceeds to step a6.

In the step a6, the reference pulse interval I
_PB and than the sum of the preset additional time T _A current pulse interval I _{P (n)} is short, i.e., currently calculated pulse interval I
If it is determined that the value of _{P (n)} is not abnormal, then at step a7, the pulse interval is longer than the value obtained by subtracting a preset subtraction time T _S , for example, 250 milliseconds, from the reference pulse interval I _PB. It is determined whether or not I _{P (n)} is short. In this step a7, the pulse interval I _{P (n)} is equal to or less than a value obtained by subtracting a preset subtraction time T _S from the reference pulse interval I _PB .
If it is determined that the value of the currently calculated pulse interval I _{P (n)} the possibility of abnormality is judged whether the heartbeat data reserve flag F _R described later is determined in step a8 is set I do.

In step a8, a heart rate data hold flag F _R described later is set, that is, the value of the previously calculated pulse interval I _{P (n-1)} may be abnormal. If the determination is determined to be pending, the processing proceeds to step a9, the current pulse interval I _{P (n)} as the current pulse interval I _{P (n)} and the previous pulse interval I _{P (n-1)} After the correction, the corrected pulse interval I _{P (n)}
There again determines in reference pulse interval I is OR or less whether the a10 steps of the value or more that is obtained by subtracting a subtraction time T _S from _PB and the reference pulse interval I _PB and the additional time T _A. Also, in step a8, the heart rate data hold flag F _R is not set, that is, the value of the previously calculated pulse interval I _{P (n-1)} is normal and the current pulse interval I _R
If it is determined that the value of _{P (n)} is abnormal, the process proceeds to step a11 to set a heart rate data hold flag F _R , and further, in step a12, a first input failure determination flag F _{The U1} and the second input failure determination flag _FU2 and the input normality determination flag _FNI are reset, and the processing after the step a1 is repeated following the next interrupt signal.

[0031] The pulse interval is set at step a9 I _{P (n)} is the reference pulse interval I _PB and preset subtraction time T _S the subtracted value or more from the reference pulse interval I _PB and the preset additional time was If it is less than or equal to the sum of T _A , that is, if it is determined in step a10 that the previous pulse interval I _{P (n-1)} is abnormal, the process proceeds to step a13 and the heart rate data hold flag F Reset _R. Then, based on the pulse interval _{IP (n)} corrected in the step a9, the current heart rate _{RH (n)} is calculated by the following equation (1) in the step a14, and in the step a15, It is determined whether or not the heart rate data timer has started counting up. R _{H (n)} = 60 / I _{P (n)}

If it is determined in step a15 that the heart rate data timer has not started counting up, the heart rate data timer starts counting up in step a16, and further in step a17. after advancing one heartbeat data number n _D, adopted as a new reference pulse interval I _PB at a18 step the set pulse interval I _{P (n)} at step a9, the predetermined period described above After the interrupt signal, the process returns to step a1.

On the other hand, in the step a6, the pulse interval
I_{P (n)}Is the reference pulse interval I_PBAnd the preset addition time T
_AIs greater than or equal to the sum of
If it is determined that a loss of
Proceed to step to make the first input failure determination flag F_U1Set
In step a20, an input normality determination flag described later
F_NIIt is determined whether or not is set.
Input normality determination flag F described later in step_NISet
Has been determined, that is, the previous input was normal
In this case, the process proceeds to step a21 and the input
The pulse interval I already set as the initial time of the image_{P (n)}
And start counting up from here.
In step 22, the input failure timer
Value T _CIIs a preset time T_RI, For example, from 3 seconds
Is also determined.

[0034] When the count value T _CI by the input defect integrating timer is determined in step a22 is equal to or less than the preset time T _RI, the process proceeds to step of the a1 after the predetermined period interrupt signal described above . In step a22, the count value T _{CI of the} input failure integrating timer is used.
There has exceeded the set time T _RI, that is, the heartbeat pulse data read in a1 of step is determined to be continued abnormal, sets the heartbeat data number N _D to 0 in step a23 and, after resetting the counting up of the input defect integrating timer at a25 step is reset further to zero the count value T _CR of the heartbeat data timer at a24 step, following the predetermined period interrupt signal described above The process proceeds to step a1 again.

[0035] Also, the input normal determination flag F _NI determined in step a20 is not set, that is, if it is determined that the previous input is abnormal, the input defect integrating timer proceeds to step a26 It is determined whether or not the count-up has started. If it is determined in step a26 that the count-up of the input failure accumulation timer has started, the process proceeds to step a22 described above. Conversely, if it is determined in step a26 that the count-up of the input failure integration timer has not started, the count-up of the input failure integration timer is started in step a27, Following the interrupt signal, the process returns to step a1.

The pulse interval I _{P (n)} set in the step a9 is shorter than a value obtained by subtracting the subtraction time T _S from the reference pulse interval I _PB , or the pulse interval I _{P (n)} is used as a reference. Longer than the sum of the pulse interval I _PB and the addition time T _A ,
That is, if the pulse interval I _{P (n)} corrected this time is also abnormal, a1
If it is determined at 0 in step sets the second input defect determination flag F _U2 proceeds to step a28,
Further, the first input defect at step a29 determination flag F _U1
After resetting the input normality determination flag F _NI and the heart rate data hold flag F _R , and further starting counting up the input failure integration timer in step a30,
After the above-described interrupt signal of the predetermined cycle, the process returns to step a1.

Furthermore, the pulse interval I _{P (n)} is longer than the value obtained by subtracting the subtraction time T _S from the reference pulse interval I _PB at a7 step, i.e. currently calculated pulse interval I _{P (n)}
If it is determined that is normal, and sets the normality input determination flag F _NI employed in the determination step of the proceeds to step a31 a20, the second input defect determination flag determined in step a32 F _U2 Is set or not. If the second input failure determination flag _FU2 is set at step a32, that is, if it is determined that an abnormal heartbeat pulse has been detected twice consecutively, the process proceeds to step a33 and the input failure is determined. the count value T _CI of integration timer is reset to 0, and resets the heartbeat data number N _D to 0 in step a34, further a3
The heartbeat data timer at 5 steps count value T _CR
After resetting to 0, the process proceeds to step a14.

On the other hand, if the second input failure determination flag _FU2 is not set in step a32,
In step a36, it is determined whether or not the first input failure determination flag _FU1 is set.
If the first input failure determination flag F _U1 is set in step 6, that is, if it is determined that the previously calculated pulse interval IP _(n−1) is too long, the process proceeds to step a 37. now the process moves to determines whether or not the count value T _CI of the input defect integrating timer is greater than the set time T _RI. If it is determined in step a36 that the first input failure determination flag _FU1 is not set,
Move on to step 14.

[0039] Then, at the count value T _CI of the input defect integrating timer is less than the preset time T _RI determined in step a37, that is, when it is estimated that there was a heartbeat pulse undetected between the last two performs processing of heartbeat data interpolation heartbeat pulses have not been calculated between the last two at step a38, further resets the first input defect determination flag F _U1 in a39 of the step of the a17 Move to step.

[0040] Also, the longer than the count value T _CI is the set time T _RI of the input defect integrating timer at a37 step, i.e. the pulse interval I _P calculated last time _(n-1) when the abnormally too long If it is determined that the heart rate pulse is not a normal heart rate pulse, the flow shifts to step a40 and the heart rate data number N
The _D is reset to 0, resets the count value T _CI of the input defect integrating timer 0 at a42 step resets further the count value T _CR of the heartbeat data timer to 0 in a41 of the step, the aforementioned Following the interrupt signal of the predetermined cycle, the process returns to step a1.

Although the heart rate data calculated by the heart rate processing means 13 and 14 should be basically the same, if the heart rate data is different for some reason, the safety of the control is reduced. In consideration of this, the signal selecting means 15 adopts the one of the two heartbeat processing means 13 and 14 which outputs a large heart rate, and outputs this to the heartbeat processing means 18. In this embodiment, since the two infrared heart rate sensors 11 and 12 are employed, an accurate heart rate can be calculated even when the steering wheel 33 is gripped by one of the left and right hands. In this case, it is natural that the output from the heart rate processing means that outputs the normal heart rate data is employed.

The heart rate data processing means 18 considers the periodic fluctuation of the heart rate accompanying the breathing action of the driver, and the heart rate becomes about 3 to 5 during one breathing action at rest. In this embodiment, the average value of the past four heart rate data (hereinafter, referred to as a four-point moving average heart rate) is calculated, and the fluctuation of the heart rate due to the driver's breathing is averaged.
Also, based on the four-point moving average heart rate of the current time, the last time, and the previous two times, whether or not the last four-point moving average heart rate is an extreme heart rate at which the rising tendency changes from a rising tendency to a falling tendency or from a falling tendency to a rising tendency. Is calculated. Then, the gradient between adjacent extreme heart rates obtained by dividing the deviation of the adjacent extreme heart rates by these time intervals is calculated, and further, the average value of the past 10 heart rate data (hereinafter referred to as 10 points) A simple average of the heart rate for the past 30 seconds (hereinafter referred to as a moving average heart rate)
This is referred to as a 30-second average heart rate).

The heartbeat data processing in this embodiment as described above
FIG. 8 shows the flow of processing in the processing means 18. That is, b
Heart rate data from the signal selection means 15 in one step
Number N _DIIs the number of heart rate data N from the potential type heart rate sensor 16
_DEIt is determined whether or not there is the above.
Number N of heart rate data from the signal selection means 15_DIIs a potential heartbeat
Number of heart rate data N from sensor 16_DEJudging that there is more than
If so, the process proceeds to step b2 and the effective heart rate data
Number N_DAAs the infrared heart rate sensor via the signal selecting means 15
Of heart rate data N from one of the sensors 11 and 12_DI
This time, in step b3, this effective heart rate data
Data number N_DAIs a 4-point moving average heart rate R_A4Required to calculate
It is determined whether the number of necessary data is four or more. or,
The heart rate from the signal selecting means 15 in the step b1
Number of data N_DIIs the heart rate data from the potential type heart rate sensor 16.
Number N_DEIf it is determined that the number is less than
To the number of effective heart rate data N_DAAs potential heart
Number of heart rate data N from beat sensor 16_DEAdopt the above
The process proceeds to step b3.

In step b3, the number of effective heart rate data N
If it is determined that there are four or more _{DAs, the} four-point moving average heart rate R _{A4 (n)} is calculated in step b5, and the pole index of the four-point moving average heart rate R _A4 is calculated in step b6. M _AI
Is calculated based on the following equation, and it is determined in step b7 whether or not the pole index M _AI is equal to or less than 0. In addition,
If it is determined in step b3 that the number of effective heart rate data N _DA is less than 4, then in the next step b5, 4
Since the point moving average heart rate R _{A4 (n)} cannot be calculated,
It returns to the step b1 again. M _AI = ｛R _{A4 (n)} -R _{A4 (n-1)} ｝ · ｛R _{A4 (n-1)} -R
_{A4 (n-2)} ｝

In the step b7, the pole index M _AI becomes 0.
That is, the same value only in this time and the previous time, the same value only in the previous time and the last two previous times, the previous four-point moving average heart rate R _{A4 (n-1)} is larger than this time, and the previous The 4-point moving average heart rate R _{A4 (n-2)} is greater than the 4-point moving average heart rate R _{A4 (n-2)} , or the current 4-point moving average heart rate R _{A4 (n-1)} is greater than the previous 4-point moving average heart rate R _{A4 (n-1).} Average heart rate R
_A4 when it is determined that the _(n-2) is larger, the To敢E not a 4-point running average heartbeat rate of the previous as the number of the peak point heartbeat goes to b8 step _{R HP (n) R A4 (} n- ₁₎ adopted, was calculated based on the following equation peak point index M _PI of turn peak point heartbeat rate R _HP at step b9, whether this peak point index M _PI is less than 0 in step b10 Judgment. M _PI = ｛R _{HP (n)} -R _{HP (n-1)} ｝ · ｛R _{HP (n-1)} -R
_{HP (n-2)} ｝

Then, at the step b10, the pole index M
_PI is smaller than 0, that is, the previous extreme heart rate R _{HP (n -1)} is larger than the current extreme heart rate R _{HP (n)} and the last extreme heart rate R _{HP (n-2),} or On the other hand, if it is determined that it is smaller, the process proceeds to step b11 to register the previous extreme heart rate R _{HP (n-1)} , and further, to the previously registered extreme heart rate R _{HP (n )} in step b12. _-2) and the difference between the pole heart rate R _{HP (n-1)} registered this time and the slope D _RH obtained by dividing the difference by these times, and then, in step b13, the number of effective heart rate data N _DA it is equal to or is 10 or more and the number of data required for calculating a point 10 running average heartbeat rate R _A10. In the step b10, the pole index M _PI
Is equal to or greater than 0, that is, the previous extreme heart rate R _{HP (n-1)} is the same as the current or last time, or the magnitude of the extreme heart rate R _HP is determined to be present, last time, and last time before. In this case, the process proceeds to the step b13 and the previous extreme heart rate R
After resetting without registering _{HP (n-1)} , the process proceeds to step b14. In the step b7, the pole index M
_AI exceeds the 0, i.e. 4-point running average size of the heart rate R _A4 is now the last, because arranged in the order of the second last four points of the previous running average heartbeat rate R _{A4 (n -1)} is pole Even when it is determined that the heart rate is not the heart rate, the process proceeds to step b14.

In step b14, the number of effective heart rate data
N_DAIf it is determined that there are 10 or more,
To the 10-point moving average heart rate R_{A10 (n)}Calculate
Then, at step b16, the heart rate data timer is counted.
G value T_CRIs longer than 30 seconds. Above b
Effective heart rate data number N in 13 steps_DAIs less than 10
If it is determined that
10-point moving average heart rate R _{A10 (n)}Cannot be calculated, so
The process returns to the step b1 described above.

If it is determined in step b16 that the count value T _CR of the heart rate data timer is 30 seconds or more, the average heart rate R for 30 seconds is determined in step b17.
_{A30 (n)} is calculated, and the process returns to the step b1 described above. or,
In step b16, the count value T _CR of the heart rate data timer is less than 30 seconds, that is, the average heart rate R for 30 seconds.
If it is determined that _{A30 (n)} cannot be calculated,
It returns to the step b1 again.

The heart rate arousal degree determination means 19 determines that the fluctuation of the heart rate calculated by the heart rate data processing means 18 is stable, that is, the fluctuation range of the four-point moving average heart rate within a predetermined time, for example, 30 seconds. A state within a predetermined value, for example, 2 or less, is determined to be the driver's awakening stable area shown in FIG.
While calculating _A30 as a reference heart rate, the heart rate data processing means 1 after determining that the driver is in the awakening stable area.
When the extreme heart rate R _HP calculated in step 8 is slightly smaller than the reference heart rate, the driver determines that the driver is in the conflict area shown in FIG. The driver's arousal level is determined by comparing with the driver's heart rate data,
An alarm level corresponding to the arousal level is set.

FIGS. 9 to 11 show the flow of processing in the heartbeat arousal degree judging means 19 in this embodiment.
That is, the processing of the heartbeat arousal level determination means 19 in the present embodiment is performed at a predetermined cycle, for example, every interruption signal every 15 milliseconds. First, at step c1, the conflict state experienced flag _FST is set. determines whether dolphins not initially moves to c2 step because this conflict condition flag F _ST is not set, whether or not the count value T _CR of the heartbeat data timer is 30 seconds or more Judge,
Count value T _CR of the heartbeat data timer is determined in step c2 is not less than 30 seconds, that is, the heart rate data is determined to be normal for over 30 seconds, the processing proceeds to step c3 It is determined whether or not the absolute value of the value obtained by subtracting the 10-point moving average heart rate R _{A10 (n)} from the 30-second average heart rate R _{A30 (n)} calculated by the heart rate data processing means 18 is 2 or less. . If it is determined in step c2 that the count value T _CR of the heart rate data timer is shorter than 30 seconds, that is, if it is determined that the above-described 30-second average heart rate R _{A30 ( n)} cannot be calculated, The steps after c1 are repeated again based on the next interrupt signal.

In step c3, the average heart rate R for 30 seconds
_A30 subtracted by the 10-point running average heartbeat rate R _{A1 0 (n)} from the _(n) is 2 or less, i.e., if the heart rate variation state of the driver is determined that there is little, c4 In this step, from the current extreme heart rate R _{HP (n)} to the previous extreme heart rate R _{HP (n)}
It is determined whether or not the absolute value of the value obtained by subtracting _{HP (n-1)} is less than 2, and the current extreme heart rate R is determined in step c4.
_When the absolute value of the value obtained by subtracting the previous extreme heart rate R _{HP (n-1 )} from _{HP (n)} is less than 2, that is, when it is determined that the fluctuation state of the extreme heart rate R _HP is relatively slow Determines whether the counting of the extreme heart rate timer has started in step c5. In this case, since the count-up of the extreme heart rate timer has not been started at first, the process goes to step c6 to start the count-up of the extreme heart rate timer, and then, at step c7, the current extreme heart rate R
It is determined whether the absolute value of the slope D _RH between _{HP (n)} and the previous extreme heart rate R _{HP (n-1)} is less than one. Also, when it is determined in step c5 that the extreme heart rate timer has started counting up, the process proceeds to step c7.

Then, in step c7, it is determined that the absolute value of the slope D _RH of the adjacent extreme heart rate R _HP is less than 1, that is, the extreme heart rate R _HP is increasing or decreasing very slowly. If so, the process proceeds to step c8, where it is determined whether or not the pole-point heart rate gradient timer has started counting up. In this case, since the counting up of the extreme heart rate timer is not started at first, the process goes to step c9 to start counting up the extreme heart rate timer, and then the counting of the extreme heart rate timer is started at step c10. It is determined whether the value T _CP is equal to or longer than a preset time T _RP , for example, 30 seconds. Also, if it is determined in step c8 that the extreme heart rate inclination timer has started counting up, the process proceeds to step c10.

If it is determined in step c10 that the count value T _CP of the pole heart rate timer is equal to or longer than the set time T _RP, that is, if it is determined that the state in which the fluctuation range of the pole heart rate is very small continues for a long time, This time, in step c11, it is determined whether or not the count value T _CD of the pole heart rate inclination timer is equal to or longer than a preset time T _RD , for example, 30 seconds.

In step c11, it is determined that the count value T _CD of the pole heart rate inclination timer is equal to or longer than the set time T _RD , that is, the pole heart rate is extremely slowly rising or falling for a long time. the case, sets the stable awareness condition flag F _WS in step c12, and then after adopting the 30-sec average heartbeat rate R _{A30 (n)} as a reference heartbeat rate R _HB at c13 step, In step c14, the count value T _CP of the extreme heart rate timer and the count value T _CD of the extreme heart rate tilt timer are reset to 0, and the steps after c1 are repeated again based on the next interrupt signal.

In step c3, the absolute value of the value obtained by subtracting the 10-point moving average heart rate R _{A10 (n)} from the 30-second average heart rate R _{A30 (n)} exceeds 2, ie, the driver Is determined to be relatively large, or in step c4, the current extreme heart rate R _{HP (n) is} calculated based on the current extreme heart rate R _{HP (n).}
It is determined that the absolute value of the value obtained by subtracting _{HP (n-1)} is 2 or more, that is, it is determined that the extreme heart rate R _HP fluctuates relatively largely, or the slope of the extreme heart rate R _HP is determined in step c7. the absolute value of _RH D is 1 or more, i.e., the peak point heartbeat rate or R _HP is determined to be relatively steep rise or descend, the count value T _CP set time of the peak point heartbeat timer at step c10 T
_It is determined that the state has not reached _RP , that is, the state in which the fluctuation range of the extreme heart rate is small does not continue for a long time, or the count value T _CD of the extreme heart rate inclination timer has reached the set time T _RD in step c11. If no, that is, if it is determined that the state in which the extreme heart rate rises or falls extremely slowly does not continue for a long time, the process proceeds to step c15, and 3 is subtracted from the reference heart rate R _HB within the past 20 seconds. It is determined whether there is an extreme heart rate R _HP equal to or greater than the value and equal to or less than a value obtained by subtracting 2 from the reference heart rate R _HB .

[0056] reference heartbeat rate R 3 values or more subtracted from _HB and reference heartbeat rate R peak point heartbeat rate that is less than or equal to the subtraction value from 2 _HB R _HP is present in the step of the c15 within the last 20 seconds, i.e. when the transition condition due to a decrease in awareness of the driver is judged to have occurred, and sets the transition condition experienced flag F _ST goes to step c16, stable awareness condition flag at step c17 It is determined whether or not F _WS is set. The reference heart rate 3 values or more subtracted from R _HB and reference heartbeat rate R peak point heartbeat rate following the subtracted value from 2 _HB R _HP does not exist within the past 20 seconds at step c15, namely and if transition condition due to a decrease in awareness of the driver is determined not to occur, when the reference heartbeat rate R _HB is not set, the processing proceeds to step c17, wakefulness is determined in step c17 If it is determined that the stable state experienced flag F _WS has not been set, the process returns to step c1 based on the next interrupt signal. .

On the other hand, in the step c1, the conflict state
Tested flag F_STIs determined to be set
And the awakening degree stable state experienced
F_WSIf it is determined that is set, c18
The alarm preparation flag F described later in the step_PRIs set
It is determined whether or not it has been performed. Initially this alert preparation flag
F_PRIs not set, so go to step c19.
Go to the reference heart rate R_HBFrom the current 4-point moving average heart rate R
_{A4 (n)}Whether or not the value obtained by subtracting the value from 0 to 5 is
The reference heart rate R is determined in step c19._HBFrom
Current 4-point moving average heart rate R_{A4 (n)}Is 0
Over 5 or less, that is, the driver's arousal level tends to decrease
If it is determined that there is, an alarm
Behind flag F _PRAfter setting, the next interrupt signal
And the steps after c1 are repeated.

[0058] In addition, the warning preparation flag F _PR in the step of c18 has been set, that is, when the arousal level of the driver is determined to be in the downward trend is, in turn, reference heartbeat and the processing proceeds to step c21 It is determined whether the value obtained by subtracting the current heart rate _{RH (n)} from the number _RHB is smaller than 5, and this c21
In the step, the current heart rate _{RH ( n) is} calculated from the reference heart rate _RHB.
Less than 5 values obtained by subtracting, i.e. when the drop degree of heart rate is determined to be relatively small, after setting the transition to the warning level L _W to step c22 to the first level, the next interrupt The process returns to step c1 based on the signal. If the value obtained by subtracting the current heart rate R _{H (n)} from the reference heart rate R _HB in step c21 is 5 or more, that is, if it is determined that the degree of decrease in the heart rate is relatively large, The process proceeds to step c19. In step c19, it is determined that the value obtained by subtracting the current 4-point moving average heart rate R _{A4 (n)} from the reference heart rate R _HB is larger than 5, that is, the drop in the driver's heart rate is considerably large. If so, the process proceeds to step c23 and the current extreme heart rate R
_It is determined whether or not the absolute value of the value obtained by subtracting the previous extreme heart rate R _{HP (n-1 )} from _{HP (n)} is larger than 4.

[0059] The absolute value of a value obtained by subtracting the previous peak point heartbeat rate from the current peak point heartbeat rate _{R HP (n) R H P} (n-1) is determined in step c23 is greater than 4, i.e. the driver If it is determined that a great conflict condition has occurred, the process proceeds to step c24 to determine whether or not the adjacent pole heart rate timer has started counting up. If it is determined that the start-up has not been started, the count of the adjacent pole heart rate timer is started at step c25, and 1 is added to the adjacent pole heart rate data number N _DB at step c26. At step c27, it is determined whether or not the count value T _CB of the adjacent pole heart rate timer exceeds a preset time T _RB , for example, 20 seconds. If it is determined in step c24 that the adjacent pole heart rate timer has started counting up, the process proceeds to step c26.

In step c27, the adjacent extreme heart rate
Timer count value T_CBIs the set time T_RBBeyond
Large heart rate fluctuations
Is determined to be continuing, step c28
And the count value T of the adjacent pole heart rate timer_CBTo 0
And reset to the next pole point at step c29.
Number of beat data N_DBIs also reset to 0, and then the
Warning level L at step_WSet to the second level
Then, the process returns to step c1 based on the next interrupt signal.
You. In step c23, the current extreme heart rate R
_{HP (n)}From the previous extreme heart rate R_{HP (n-1)}Absolute value of subtracting
When the pair value is 4 or less,
If it is determined that there is a
Information level L _WAt the second level.

Further, in the step c27, adjacent poles are
Heart rate timer count value T_CBIs the set time T_RBBelow
Large heart rate fluctuations
If it is determined that has not continued for a long time,
And the number of adjacent pole heart rate data N_DBIs more than 3
It is determined whether the number is large or not. _DB
Is 3 or more, that is, periodic sleepiness
If it is determined that the conflict state is repeated, c3
Move to step 2 to set the alarm level L_WOn the third level
Set and step c1 based on the next interrupt signal
Return to In step c31 above, the adjacent extreme heart rate
Number of data N_DBIs less than 3, that is, the repetition of the conflict state
If it is determined that there is no data, the process proceeds to step c30.
You.

When the vehicle attempts to travel accurately in accordance with the road shape, the driver steers the steering wheel 33 to a large extent in accordance with the curve of the road on which the vehicle is traveling and finely in accordance with the road surface conditions. That is, when traveling on the road from the current position of the driver to the target position, the steering wheel 33 is largely steered along the road shape, and the driver travels on the road according to the road surface condition. At this time, the steering wheel 33 is finely controlled to instantaneously control the position of the vehicle with respect to the road. By detecting the fine steering of the steering wheel 33, the degree of awakening of the driver can be determined.

As shown in FIG. 12, which shows an extracted enlarged cross-sectional structure of a portion of the steering shaft 20 to which the steering angle sensor 21 is attached, the steering shaft 20 with the steering handle 33 integrally fixed is rotatable on a steering column 36. A gear tube 37 is coaxially and integrally fitted to the steering shaft 20, and the gear tube 3
A drive gear 38 is formed integrally with the drive gear 7. A steering angle sensor 21 which is a potentiometer is mounted on the steering column 36 adjacent to the steering shaft 20, and a driven gear 40 is integrally fitted to a rotation shaft 39 of the steering angle sensor 21. The driven gear 40 and a backlash removing gear 41 rotatable relative to the driven gear 40 are fitted. The driven gear 38 of the gear tube 37 is meshed with a driven gear 40 and a backlash removing gear 41.

Therefore, when the steering wheel 33 is operated, the steering shaft 20 rotates in conjunction with it, and the driven gear 40 rotates without play by the backlash removing gear 41 whose phase with the driven gear 40 has been adjusted in advance. The rotation corresponding to the amount of turning of the steering shaft 20 is transmitted to the rotating shaft 39 of the steering angle sensor 21. The turning state of the steering shaft 20 is detected very accurately by the steering angle sensor 21, and the electric signal is output. It can be output as.

The vehicle speed sensor 24 is of a type for detecting the rotation of the output shaft of the transmission (not shown) in the present embodiment. However, the vehicle speed sensor 24 detects the rotation based on the rotation speed of a driven wheel such as a driven wheel. Of course, it is also possible to adopt one having the following format.

The steering angle data processing means 22 calculates a standard value of a parameter of a steering component subjected to frequency analysis in the awake state of the driver based on detection signals from the steering angle sensor 21 and the vehicle speed sensor 24. The steering angle data is processed by applying a band-pass filter formed by a calculation formula called a moving average based on the absolute value of the detection signal of the steering angle sensor 21. That is, if the sampling frequency is 1
As 0 Hz, the steering angle data at every 0.1 second interval is sequentially taken in. Then, this steering angle data is subjected to FFT analysis (FA
ST FOURIER TRANSFORM (fast Fourier analysis) is performed to determine the component magnitude (power spectrum) for each frequency band.

FIG. 13 is a graph showing the motion characteristics of the driver with respect to the frequency distribution of the steering angle signal of the steering wheel 33 obtained as described above. When the vehicle is running, the driver's arousal level is reduced.
In this graph, 1 Hz means 1 Hz per second.
The turning steering wheel 33 is steered, while 0.1 Hz is steering the steering handle 33 once every 10 seconds, and 0.5 Hz is steering the steering handle 33 once every two seconds. That is. From this graph, it can be seen that if the driver's awakening degree is high, the number of times the steering wheel 33 is finely steered is increased, and if the awakening degree is reduced, the fine steering is reduced. Therefore, this steering wheel 3
It is considered that the awakening degree of the driver can be determined by detecting only the fine steering component area of No. 3 and comparing it with a preset reference value.

That is, the detection data is processed by a so-called moving average calculation in which the average value of a plurality of points for each sampling period from the present to the past is obtained by a low-pass filter of a predetermined frequency or less, thereby dividing the data into a predetermined frequency band. it can. Specifically, from the graph shown in FIG. 13, the fine steering component 33 of the steering wheel 33 is set to the visual steering component region S, and the steering wheel 33 is set to a range of 0.3 Hz or less.
Is cut because it is a parameter indicating the amount of steering that largely steers along the road shape, and cuts more than 1.0 Hz. The visual steering component will be described later.

The frequency band is divided by calculating a moving average. In general, the sample interval is I _S seconds,
Assuming that the cutoff frequency is f, the number M of samples to be averaged can be obtained by the following formula. _{M = 0.443 / (I S ·} f)

[0070] Therefore, in order to obtain the following steering component area S _H 1.0 Hz, calculates the number M _H of the specimen when the cut-off frequency f = 1.0 Hz. Specimens when _{M H = 0.443 / (0.1 ×} · 1.0) = 4.43 Further, in order to obtain the following steering component area S _L 0.3 Hz, the cutoff frequency f = 0.3H _{Z Is} calculated. M _L = 0.443 / (0.1 × 0.3) = 14.8 Thus, the number M of samples for dividing the visual steering component area S
It is calculated as _{H = 4, M L = 15} .

Therefore, sampling from the present to the past
4-point moving average steering angle P for each cycle_A4And 15-point moving average
Rudder angle P_A15Is calculated, and these 1 second and 7 seconds
Interval, that is, the sampling period is 0.1 second
The four-point moving average steering angle P_A410-point moving average
Below, this is called a 10 × 4 point moving average steering angle) P
_{A4-1 0}And 70 points moving average (hereinafter referred to as 70 × 4 points
Moving average steering angle) P_A4-70And 15 points moving flat
Average steering angle P_A1510-point moving average (hereinafter referred to as 10
X 15-point moving average steering angle) P_A15-10And 70
Point moving average (hereinafter referred to as 70 × 15 point moving average steering)
Horn) P_A15-70Are calculated respectively. Soshi
By calculating these differences, the visual steering component range S
Parameter P_S10, P _S70Can be calculated.

By the way, in this embodiment, when a graph showing the visual steering component of the driver with respect to the frequency distribution of the steering angle signal of the steering wheel 33 shown in FIG. The driver's visual steering component during driving (the graph shown by the solid line) and the visual steering component of the driver during the drowsy driving with reduced arousal level (the graph shown by the broken line) are obtained.

In general, a driver draws a road segment or a road segment based on visual information of a “road shape ahead” and a “current position of the vehicle on the road” in consideration of the driving speed. It is considered that the steering wheel 33 is operated so as to trace the target course. Therefore, the present inventor investigated how this visual restriction affects the operation characteristics of the steering wheel 33 by restricting a part of the visual information. In other words, the steering wheel 33 exerted by “running speed” and “individual difference” mainly on “restriction of driver's visual information”
The presence of visual steering and kinesthetic steering was confirmed from the influence on the operating angular frequency characteristics of This has already been
On March 7-8, “Dynamic and Design Conferenc”
e 1992 ", and the outline of the test content is described below.

In a test study on the operating characteristics of the steering wheel 33 by the driver, the vehicle was driven at a predetermined traveling speed on a predetermined curved road, and at this time, a part of the driver's glasses was masked to restrict the visibility. . That is, as shown in FIG. 15, a running test was performed while limiting the visibility ahead of the vehicle 42 by a predetermined distance, and the characteristics of the steering angle data of the steering wheel 33 at this time were analyzed by frequency analysis. As a result, when frequency analysis is performed on both the case where the driver normally travels and the case where the driver drives the vehicle with the upper view restricted, as shown in FIG. Appeared. What can be estimated from this analysis result is 0.3-1.0.
By saying that the data in the region of Hz is a fine feedback correction steering that controls the positional relationship between the vehicle 42 and the road immediately before the vehicle 42 based on visual information in the operation of the steering wheel 33, that is, a visual steering component. is there. In this test, since the upper field of view was restricted, it can be said that the visual steering component appeared more remarkably than during normal driving.

Therefore, the steering angle data of the steering wheel 33 is subjected to frequency analysis, and the data in the range of 0.3 to 1.0 Hz is extracted from the obtained result, whereby the fine steering component of the steering wheel 33, that is, the visual steering component is obtained. Can be detected,
In addition, the degree of awakening of the driver can be determined based on the data of the visual steering component region, since the tendency matches the graph shown in FIG.

FIGS. 16 and 17 show the flow of processing in the steering angle data processing means 22 in this embodiment. That is, the steering angle data processing means 2 in this embodiment
The process 2 is performed at every predetermined interval, for example, every 15 milliseconds of the interrupt signal. First, at step d1, the steering angle θ and the vehicle speed from the steering angle sensor 21 are sampled every 0.1 seconds. The vehicle speed V from the sensor 24 is read. Then, it is determined in step d2 whether or not the absolute value of the read steering angle θ is less than 10 °. If it is determined that the absolute value of the steering angle θ is less than 10 °, the process proceeds to step d3. If it is determined that the absolute value of the steering angle θ is equal to or greater than 10 °, the process proceeds to step d4, resets the number of effective steering angle data N _S so far to 0, and then returns to d1.
Return to step. When the steering angle θ is equal to or greater than 10 °, the driver is operating the steering wheel 33 largely, and at this time, a visual steering component necessary for determining the degree of awakening of the driver is obtained. Data is not appropriate.

The vehicle speed V read in step d3
The vehicle speed V is determined to be 30 km / h or more.
If it is determined that the vehicle speed V is equal to or greater than / h, the process proceeds to step d5. If it is determined that the vehicle speed V is less than 30 km / h, the process proceeds to step d4. Back again to d1 of the step the N _S is reset to 0. When traveling at a vehicle speed V of less than 30 km / h, for example, when traveling at a low speed on a congested road,
At this time, since the driver may operate the steering wheel 33 meaninglessly, data that is not appropriate as data necessary for determining the awakening level of the driver may be introduced. Therefore, as described above, the absolute value of the steering angle θ is 10
° or more, or when the vehicle speed V is less than 30 km / h, d4
The steering angle θ read in the step is not adopted.

[0078] The steps in the d5, advancing one effective steering angle data number N _S which is employed in step d2 and d3. Then, it is judged whether there effective steering angle data number N _S is 4 or more in step d6, if it is determined that four or more processing proceeds to step d7. Then, this calculated at d7 step the 4-point running average steering angle P _A4 goes to d8 step, the 4-point running average steering angle data of four points were calculated running average steering angle P _A4 at step d7 The number N _P4 is increased by one. Incidentally, if it is determined that the effective steering angle data number N _S is not more than three in the step of d6 is the 4-point running average steering angle determined in step d7 P _A4
Cannot be calculated, the process returns to step d1.

[0079] effective steering angle data number N _S is determined whether or not 15 or more at d9 steps subsequent to d8 step, and when it is determined that more than 15 proceeds to step d10. Then, it is determined in step d10 to calculate the 15-point running average steering angle P _A15 shifts at d11 step, advancing one 15-point running average steering angle data number N _P15. In the case where step at 15 point running average steering angle data number N _S of d9 is determined that no more than 15, the step at 15 point running average steering angle P of d10
_Since the calculation process of _A15 cannot be performed, the process returns to the step d1 again.

In the step d12, it is determined whether or not the four-point moving average steering angle data number N _P4 is 10 or more. If it is determined that the number is 10 or more, the process proceeds to the step d13 and the above-mentioned 10 × The four-point moving average steering angle P _A4-10 is calculated, and the _{process proceeds} to d14. And this d1
15 points in the fourth step running average steering angle data number N _{P1 5}
Is determined to be 10 or more, and if it is determined to be 10 or more, the process _proceeds to step d15 to calculate the 10 × 15-point moving average steering angle _PA15-10 described above, and d16
Go to step. If it is determined in the steps d12 and d14 that the 4-point moving average steering angle data number N _P4 or the 15-point moving average steering angle data number N _P15 is not 10 or more, 10 × in the steps d13 and d15. 4
Since the point moving average steering angle _PA4-10 and the 10 * 15 point moving average steering angle _PA15-10 cannot be calculated, the process returns to step d1.

In step d16, it is determined whether or not the number of four-point moving average steering angle data N _P4 is 70 or more. The four-point moving average steering angle P _A4-70 is calculated, and the process _proceeds to d18. Then, in the step d18, the number of 15-point moving average steering angle data N _P15 is 7
It is determined whether there is 0 or more, and if it is 70 or more, the process proceeds to step d19 and the above-mentioned 70 × 15
The point moving average steering angle _PA15-70 is calculated. In the steps d16 and d18, the four-point moving average steering angle data number N
If it is determined that _P4 or the 15-point moving average steering angle data number N _P15 is not 70 or more, d17 and d19
Since the calculation processing of the 70 × 4 point moving average steering angle _PA4-70 and the 70 × 15 point moving average steering angle _PA15-70 cannot be performed in the step, the _flow returns to the step d1 again.

The steering arousal degree determination means 23 calculates a reference value (hereinafter, referred to as a reference value) of a frequency-analyzed steering component parameter calculated by the steering angle data processing means 22 in the awake state of the driver.
This is referred to as a reference parameter), and the present driver's arousal level is determined, and an alarm level corresponding to the arousal level is set. That is, the 10 × 4 point moving average steering angle P calculated by the steering angle data processing means 22
_A4-10 and 70 × 4 point moving average steering angle P _A4-70 and 10 ×
The parameters P _S10 and P _S70 of the visual steering component area S are calculated from the 15-point moving average steering angle P _A15-10 and the 70 × 15-point moving average steering angle P _A15-70 based on the following equations, respectively. I do. P _S10 = | P _A4-10 −P _A15-10 | P _S70 = | P _A4-70 −P _A15-70 | And the parameters P _S10 , P of the visual steering component area S
_By comparing _S70 with a preset reference parameter, the degree of awakening of the driver is determined.

In this embodiment, the steering awakening degree determination
FIGS. 18 and 19 show the flow of processing in the setting means 23.
You. That is, the steering arousal level determination unit 23 in the present embodiment
The processing is performed at predetermined intervals, for example, every 15 milliseconds.
It is performed every time, but first, 70x4 points in the step of e1
Moving average steering angle P_A4-70And 70 × 15-point moving average steering
Angle P_A15-70From the absolute value of the difference from
Parameter P_S70Is calculated. And in the step of e2
P of the visual steering component area S calculated by _S70Is based
Quasi-parameter P_SS70It is determined whether or not
Parameter P of rudder component area S_S70Is the reference parameter P_SS70
If it is determined that the difference is less than the above, the process proceeds to step e3.
You.

In step e3, the 10 × 4 point moving average steering angle P _A4-10 and the 10 × 15 point moving average steering angle P _A4-10 are used.
Calculating the parameters P _{S1 0} of the visual steering component area S from the absolute value of the difference between _A15-10. Then, whether the parameter P _S10 of the visual steering component area S is the reference parameter P _SS10 less determined at step e4, the parameter P _S10 of the visual steering component area S is a reference parameter P _SS10 less If it is determined, the process proceeds to step e5.

This reference parameter is set in accordance with the degree of arousal of the driver. In this embodiment, 0.21 is set as the reference parameter P _{S S70} corresponding to the visual steering component parameter P _S70. The reference parameter P _SS10 corresponding to the visual steering component parameter P _S10 is 0.1.
7 is set. Then, the calculated parameters P _S10 and P _S70 of the visual steering component area S are changed to the reference parameter P
_SS70, alarm level was compared with the P _SS10 corresponding to the degree of awakening L _W
Set. Note that these reference parameters P _SS70 , P
_SS10 is set based on the graph shown in FIG. 13 showing the visual steering components of the case where the awakening degree of the driver with respect to the frequency distribution is reduced and the case where the awakening degree is high with respect to the frequency distribution as described above. These numerical values are not limited to the values in the above-described embodiment, and may be appropriately set based on various conditions.

Note that the parameter P _{S70 of} the visual steering component area S calculated in step e2 is the reference parameter P
When it is determined that it is larger than _{SS70, the process proceeds} to step e6, and when it is determined that the parameter P _{S10 of} the visual steering component area S calculated in step e4 is larger than the reference parameter P _SS10. Goes to step e6. In step e6, the count value _TCU of the awakening degree reduction timer is reset to 0 when it is determined that the driver's awakening degree is high, and the steps after e1 are repeated again based on the next interrupt signal.

In step e5, it is determined whether or not the awakening degree reduction timer has started counting up. Is started, and at step e8, the count value T _CU of the awakening degree reduction timer is set to a preset time T _RU , for example, 3
Seconds or not, that is, P _S70 ≧ P _SS70 and P _S10 ≦
State of the P _SS10, it is determined whether to continue the set time T _RU or higher, which proceeds to count the awareness decrease timer e6 of the steps described above when it is determined that the set is less than time T _RU The value _TCU is reset to 0, but if it is determined that it is not, the process proceeds to step e9.

At step e9, it is determined whether or not the alarm switching timer has started counting up. If it is determined that the alarm switching timer has not started counting up,
At step e10, the count of the alarm switching timer is started, and at step e11, the count value T _CW of the alarm switching timer is set to the first addition time T _AL set at the preset reference alarm switching time T _BW , For example, it is determined whether it is longer than the time obtained by adding 4 seconds. When the count value T _CW of the alarm switching timer is longer than the sum of the reference alarm switching time T _BW and the first addition time T _AL , that is, when it is determined that the awakening degree of the driver is the lowest. Goes to step e12, sets the alarm level L _W to the third level, and then goes to step e17 to be described later.

If it is determined in step e11 that the count value T _CW of the alarm switching timer is not longer than the sum of the reference alarm switching time T _BW and the first addition time T _AL , e13 Then, it is determined whether or not the count value T _CW of the alarm switching timer is longer than a second addition time T _AS set in advance to the reference alarm switching time T _BW , for example, 3 seconds. If it is determined that the count value T _CW of the alarm switching timer is longer than the sum of the reference alarm switching time T _BW and the second addition time T _AS , the process proceeds to step e14 and the alarm level L Set _W to the second level.

Further, if it is determined in step e13 that the count value T _CW of the alarm switching timer is not longer than the sum of the reference alarm switching time T _BW and the second addition time T _AS , the process proceeds to step e15. the count value T _CW of the warning change-over timer step determines whether long or not than T _BW between the reference warning change-over time. Then, the count value T of the alarm switching timer
When _{the CW} is determined to longer than T _BW between the reference warning change-over time is a warning level L _W proceeds to step e16 first
After the level is set, the process proceeds to step e17 described later.

If it is determined in step e14 that the count value T _CW of the alarm switching timer is equal to or less than the reference alarm switching time T _BW , the process proceeds to step e17 to count the count value T _CU of the awakening degree reduction timer. After resetting the count value T _CW of the alarm switching timer to 0, the steps after e1 are repeated based on the next interrupt signal.

The tactile alarm means 26 enables a pair of left and right side supports 44 provided on the seat back 43 of the driver's seat 25 to rotate in the direction of the arrow in FIG. Tighten from both sides,
Conversely, by repeating the operation of separating the side support 44 from the flanks or the like, the driver's arousal level is enhanced by tactile sensation. The first mentioned above
It is adapted to operate in response to the level of the warning level L _W.

The visual warning means 28 embeds a display 45 for transparently displaying a drowsiness warning in the front window 27 in front of the driver's seat 25. In the energized state without generation, for example, the drowsiness warning mark 46 as shown in FIG. 2 blinks in a transparent state, and visually enhances the driver's arousal level. It is adapted to operate in response to the warning level L _W.

Further, the audible alarm means 29 audibly enhances the arousal level of the driver by blowing an alarm buzzer 48 incorporated in the instrument panel 47. and when the grip condition of the driver is not correct for the 33, is adapted to operate in response to the warning level L _W of the third level described above.

[0095] In this embodiment, the steering wheel grip failure alarm means 34 includes two alarm means 2 as described above.
6, 29 is used. Side support 4
By changing the movement of the 4 and the sound of the alarm buzzer 48 from the case for improving the alertness, it is possible for the driver to easily determine whether the grip of the steering wheel 33 is good or whether the alarm is a drowsy driving. Care is taken so that they can be distinguished.

[0096] The alarm control unit 30, based on warning level L _W which is determined respectively by the heartbeat awareness determination means 19 and the steering awareness determination means 23, the operation of the three warning means 26, 28, and 29 described above is intended to control, when the signal of the oN operation of the alarm release switch 31 by the driver is input, three warning means based on the warning level L _W 26,2
The operation of 8, 29 is stopped. But,
Alarm means 26, 2 as handle grip failure alarm means 34
When the driver 9 is operated, the operation is not stopped even if the driver turns on the alarm release switch 31.

FIGS. 20 and 21 show the flow of the alarm process by the alarm control means 30. That is, the alarm processing in the present embodiment is performed at a predetermined cycle, for example, every interruption signal every 15 milliseconds. First, at step f1, it is determined whether the alarm level _LW is the first level. If it is determined that the alarm level _LW is the first level, the process proceeds to step f2 to determine whether or not the alarm occurrence flag _FWG is set. When the step in warning generation flag F _WG of the f2 has been determined not to be set starts counting up of the warning change-over timer with setting the warning generation flag F _WG at f3 step, f4 In the step, the count value T _CW of the alarm switching timer is set to a first preset time T _WL , for example, 1
It is determined whether or not 0 seconds has elapsed.

If it is determined in step f4 that the count value T _CW of the alarm switching timer is equal to or less than the first set time T _WL , the process proceeds to step f5 to activate the tactile alarm means 26. After the side support 44 is separated or pressed against the driver's flanks to urge the driver to wake up by touch, f based on the next interrupt signal
Return to step 1.

If it is determined in step f2 that the alarm occurrence flag _FWG has been set, then f4
And the alarm switching timer count value T _CW
Is again determined whether or not exceeds the first set time T _WL .

In step f4, if the count value T _CW of the alarm switching timer exceeds the first set time T _WL , that is, if the driver's awakening level does not return only by the activation of the tactile alarm means 26. If it is determined, the process proceeds to f6 step sets the warning level L _W in two levels, further f7
The alarm generation flag _FWG is reset in the step of and the count value T _{CW of the} alarm switching timer is reset in the step of f8.
After resetting to 0, the visual warning means 28 is activated at step f9, a warning mark 46 is displayed on the front window 27, and the driver is visually awakened.
The process returns to step f1 based on the next interrupt signal.

[0102] When the step at the warning level L _W of the f1 is determined not to be a first level, it determines whether the transition to the warning level L _W in step f10 is a second level. When the alarm level L _W is determined in step f10 it is determined as the second level, f
Warning generation flag F _WG proceeds to step 11 to determine whether it is set, when the warning generation flag F _WG is determined in step f11 is determined not to be set, in step f12 begins counting up of the warning change-over timer with setting the warning generation flag F _WG Te, it determines whether or not the count value T _CW of the warning change-over timer is determined in step f13 exceeds the first preset time T _WL I do.

If it is determined in step f13 that the count value T _CW of the alarm switching timer is less than or equal to the first set time T _WL , the flow proceeds to step f9 to activate the visual alarm means 28. Then, an alarm mark 46 is displayed on the front window 27 to urge the driver to wake up. In addition,
If the step in the warning generation flag F _WG of the f11 is determined to have been set, whether the count value T _CW of the warning change-over timer step f13 exceeds the first preset time T _WL It is determined again whether or not it is.

At the step f13, the count value T _CW of the alarm switching timer exceeds the first set time T _WL .
That is, when the operation of the visual warning means 28 determines that not return the awareness of the driver sets the transition to the warning level L _W in step f14 to the third level, further alarm at f15 in steps The flag _FWG is reset, and the count value T _{CW of the} alarm switching timer is set at step f16.
Is reset to 0, the auditory alarm means 29 is activated in step f17, the alarm buzzer 48 is sounded to urge the driver to awake by hearing, and then the process returns to step f1 based on the next interrupt signal. .

At the step f10, the alarm level L _W
There when it is determined that it is not the second level, determines whether transition to the warning level L _W in step f18 is the third level, the warning level L is determined in step f18
If it is determined that _W is at the third level, the process proceeds to step f19 to determine whether or not the alarm occurrence flag _FWG is set. When it is determined that the warning generation flag F _WG is determined in step f19 is set actuates the auditory warning means 29 proceeds to step of the f17, driver blew a warning buzzer 48 Encourage your awakening. Further, when it is determined that the warning generation flag F _WG proceeds to step f19 is not set, the warning change-over timer at f21 in step with setting the warning generation flag F _WG proceeds to step f20 After the count-up is started, the process proceeds to step f17.

On the other hand, the flow shifts to step f18 to issue an alarm
Bell L_WIs not at the third level, f
Move to step 22 to set the conflict state experienced flag F_ST
Is set or not, this conflict state experience
Completed flag F_STIf it is determined that is set
Are the three alarm means 26, 28, 2 in step f23.
9 are all stopped, and at step f24,
Wisteria state experienced flag F _STReset. Also, the f
Move to step 22 to set the conflict state experienced flag F_ST
If it is determined that is not set,
Then, the process returns to the step f1 based on the interrupt signal.

The handle grip failure alarm processing unit 35 incorporated in the alarm control means 30 includes a heart rate processing means 13, 1.
Based on the information of the input normal determination flag F _NI is set in the course of processing at 4,17, and estimates the grip degree of the steering wheel 33 by the driver, controls the operation of the steering wheel grip defect warning means 34 described above If the input normality determination flag F _NI has not been set for a certain period of time, the tactile warning means 26 is first activated to call the driver's attention. The alarm means 29 is further operated.

FIG. 22 shows the flow of processing based on the information from the heartbeat processing means 17 in the steering wheel grip failure alarm processing section 35 of this embodiment. That is, the processing of the steering wheel grip failure alarm processing unit 35 in the present embodiment is
For example, it is performed at every 15 millisecond interrupt signal,
First, determine whether the set of input normal determination flag F _NI performed in heartbeat processing means 13, 14, and 17 is performed in step g1, the input normal determination flag F _NI is not set, That is, when it is determined that there is a possibility that the driver's gripping state on the steering wheel 33 is not correct, the process proceeds to step g2 to determine whether or not the count value T _CI of the input failure integration timer is equal to or longer than the set time _TRI . Is determined.

[0108] When the count value T _CI of the input defect integrating timer is determined in step g2 is determined to be the set time T _RI or more, the count-up is started in the steering wheel grip defect warning preparation timer in step g3 If it is determined that the count-up of the steering wheel grip failure alarm preparation timer has not started,
At step g4, the count of the handle grip failure alarm preparation timer is started, and at step g5, the count value T _{CS of the} handle grip failure alarm preparation timer exceeds a preset time T _RS , for example, 2 seconds. Determine whether or not. Further, when it is determined that the steering wheel grip defect warning preparation timer has begun counting up in step g3, the count value T _CS of the steering wheel grip defect warning preparation timer goes to this g5 steps the setting Time T
Determine whether or not _RS is exceeded.

The process proceeds to step g5 and the handle is gripped.
Value T of the alarm failure preparation timer_CSIs the set time T_RS
If it is determined that the value exceeds the limit, the process proceeds to step g6.
The handle grip failure alarm switching timer
To determine whether or not the grip has been started
The count-up of the fault alarm switching timer has not started.
If it is determined that the operation is
Start counting up the dollar gripping failure alarm switching timer
Then, in step g8, switch the handle grip
Ma's count value T_CHIs a preset time T_RHFor example
It is determined whether it has exceeded 3 seconds. Also, the step of g6
And the handle grip failure alarm switching timer counts down.
If it is determined that the backup has started, this g8
Step to the handle grip failure alarm switching timer
Count value T_CHIs the set time T _RHWhether or not
Is determined.

Then, at the step of g8, grip the steering wheel.
Count value T of failure alarm switching timer _CHIs the set time T_RHLess than
It is below, that is, the steering wheel 33 is not properly gripped.
If it is determined that the duration of the state is short, the step of g9 is performed.
And the tactile alarm means 26 is activated, and the driver's
Pull or push the side support 44 against the side
And the driver correctly grips the steering wheel 33
Alerts the user tactilely and then responds to the next interrupt signal.
Then, the process returns to the step g1.

In step g8, the user grips the steering wheel.
Count value T of failure alarm switching timer _CHIs the set time T_RHTo
Exceeding, that is, driving only by activation of the tactile alarm means 26
If it is determined that it is not possible to call the attention of the person,
The operation proceeds to the step, and the auditory alarm means 28 is further operated,
Side support 44 pulled away from driver's side
Alarm and sound an alarm buzzer.
Tactile sense and hearing so that the diver can grasp the steering wheel 33 correctly.
After alerting the user visually, the next interrupt signal
To go back to step g1.

[0112] In addition, the count value T _CS of the steering wheel grip defect warning preparation timer set time at g5 of step T _RS
If it is determined to be the following, the process returns to step g1 based on the next interrupt signal. In step g1, the input normality determination flag F _NI is set, that is, when it is determined that the driver is gripping the steering wheel 33 correctly, or in step g2, the count value of the input failure integration timer is determined. If the T _CI is determined to be smaller than the set time T _RI is the operation of the steering wheel grip defect warning means 34 is reset to zero the count value T _CS of the steering wheel grip defect warning preparation timer and proceeds to step g13 After stopping, the process returns to step g1 based on the next interrupt signal.

Although the processing flow of the steering wheel grip failure alarm processing section 35 based on the information from the heart rate processing means 17 corresponding to the potential type heart rate sensor 16 has been described with reference to FIG. It goes without saying that similar alarm processing is performed by the steering wheel grip failure alarm processing section 35 based on the information from the heartbeat processing means 13 and 14.

The reference value correction unit 32 includes an alarm unit 26,
After the operation of 28 and 29, the driver releases the alarm release switch 3
If the time is short, it is determined that the awakening degree of the driver is relatively high, and the warning means 2 is used.
The reference heart rate R _HB and the reference alarm switching time T _BW are corrected to be higher so that 6, 28, 29 become more difficult to operate, and the driver issues an alarm after the alarm means 26, 28, 29 is activated. If it takes a long time until the release switch 31 is operated, it is determined that the awakening degree of the driver is lower than expected, and the warning means 26, 28, and 29 are activated relatively early. Reference heart rate _RHB and reference alarm switching time _TBW
Is corrected to a lower value, and the corrected reference heart rate R _HB
And is intended to output the T _BW between the reference warning change-over time to the heartbeat awareness determination means 19 and the steering awareness determination means 23.

FIG. 23 shows the flow of processing in the reference value correction section 32 in this embodiment. That is, the processing of the reference value correction unit 32 in this embodiment is started by turning on the alarm release switch 31. First, the alarm release flag _FST is set in step h1, and then the alarm is released in step h2. It is determined whether the count value T _CW of the switching timer has exceeded a second preset time T _WM , for example, 6 seconds.

In step h2, the alarm switching timer
Count value T_CWIs the second set time T_WMBeyond
The driver's reaction is not too fast
Moves to step h3, and the current warning is the
It is determined whether or not the alarm is based on the information from the determination unit 23,
This warning is based on the information from the steering arousal degree determination means 23.
If it is determined that the alarm is issued, go to step h4
And the reference alarm switching time T _BWReset by one second
So that the alarm means 26, 28, 29 operate later than before.
You. Further, at step h5, the counter of the alarm switching timer is counted.
G value T_CWAfter resetting to 0,
Then, the process returns to the step h1. Step h3
At this time the information from the steering alertness determination means 23
It is not a warning based on, that is, from the heartbeat alertness determination means 19
If it is determined that the warning is based on the information of
Move to step and reference heart rate R_HBSet one less
Fix, alarm means 26, 28, 29 operate later than before
After that, in step h5, the alarm switching timer
Count value T_CWIs reset to 0.

On the other hand, if it is determined in step h2 that the count value T _CW of the alarm switching timer is equal to or less than the second set time T _WM , the process proceeds to step h7, and this time the alarm switching timer starts counting. the count value T _CW is the third preset time T _WS, for example, to determine shorter or not than 2 seconds, the count value T _CW is less than the third set time T _WS, i.e. the driver of the reaction very If it is determined that it is earlier, the process proceeds to step h8, and it is determined whether or not the current warning is a warning based on information from the steering arousal degree determination means 23. Then, in this step h8, the current warning is issued by the steering arousal level determination means
If it is determined that the warning is based on the information from 3,
proceeds to h9 step reconfigure one second lot of T _BW between the reference warning change-over time, after the warning means 26, 28, and 29 was set to operate slower than before, further proceeds to step h5. If it is determined in step h8 that the current alarm is not an alarm based on the information from the steering arousal level determination unit 23, that is, if it is an alarm based on the information from the heart rate arousal level determination unit 19, the process proceeds to step h10. And reset the reference heart rate R _HB by one, and set the alarm means 26, 28, 2
After 9 is operated later, the process proceeds to the step h5.

If it is determined in step h7 that the count value T _CW of the alarm switching timer is equal to or longer than the third set time T _WS , the current reference heart rate R _HB and the reference alarm switching time T T Without changing _BW , the process proceeds to step h5 to reset the count value T _CW of the alarm switching timer to 0.

[0119]

As described above in detail with reference to the embodiments, according to the awakening degree determination apparatus of the present invention, the steering angle sensor detects the steering angle of the running vehicle, and the steering angle data processing means. Calculates the frequency distribution of the steering angle signal based on the output of the steering angle sensor, and the driver performs steering based on the visual information.
The parameters of the driver's steering characteristics are obtained by extracting the visual steering component that is present , and the arousal level determination means compares the parameters of the steering characteristics with a preset reference value to determine a decrease in the arousal level. Therefore, there is no need to provide a separate detection device for determining the driver's arousal level, such as a heart rate sensor, and based on a completely new knowledge of obtaining the parameters of the steering characteristics from the steering angle signal from the existing steering angle sensor. The driver's arousal level can be determined,
Irrespective of the driver's driving posture and without giving the driver annoyance, the awakening degree of the driver can be reliably and accurately determined.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic structure of an embodiment of a vehicle drowsiness alarm device according to the present invention.

FIG. 2 is a perspective view illustrating an appearance of a vehicle interior in the embodiment.

FIG. 3 is a graph showing a change over time in a driver's arousal level.

FIG. 4 is a conceptual diagram showing a relationship between a heart rate pulse from a heart rate sensor and heart rate data calculated by a heart rate processing unit.

FIG. 5 is a flowchart showing the flow of processing by the heartbeat processing means of the present embodiment together with FIGS. 6 and 7.

FIG. 6 is a flowchart showing the flow of processing by the heartbeat processing means of the present embodiment together with FIGS. 5 and 7;

FIG. 7 is a flowchart showing the flow of processing by the heartbeat processing unit of the present embodiment, together with FIGS. 5 and 6.

FIG. 8 is a flowchart illustrating a flow of a process performed by the heartbeat data processing unit of the present embodiment.

FIG. 9 is a flowchart showing the flow of processing by the heartbeat arousal level determining means of the present embodiment together with FIGS. 10 and 11;

FIG. 10 is a flowchart showing the flow of processing by the heartbeat arousal level determination means of the present embodiment, in conjunction with FIGS. 9 and 11;

FIG. 11 is a flowchart showing the flow of processing by the heartbeat arousal level determination means of the present embodiment, together with FIGS. 9 and 10;

FIG. 12 is an extracted enlarged sectional view of a portion of a steering shaft to which a steering angle sensor is attached.

FIG. 13 is a graph showing a visual steering component of a driver with respect to a frequency distribution of a steering angle of a steering wheel.

FIG. 14 is a graph showing a frequency distribution of a steering angle of a steering wheel when an upper visibility limit is given to a driver.

FIG. 15 is a schematic diagram illustrating an upper visibility restricted area of a vehicle driver.

FIG. 16 is a flowchart showing the flow of processing by the steering angle data processing means of the present embodiment together with FIG.

FIG. 17 is a flowchart showing the flow of processing by the steering angle data processing means of the present embodiment together with FIG.

FIG. 18 is a flowchart showing the flow of processing by the steering arousal level determination means of this embodiment together with FIG.

FIG. 19 is a flowchart showing the flow of processing by the steering arousal level determination means of the present embodiment together with FIG. 18;

FIG. 20 is a flowchart showing the flow of an alarm process by the alarm control means of the present embodiment together with FIG. 21;

FIG. 21 is a flowchart showing the flow of an alarm process by the alarm control means of the present embodiment together with FIG. 20;

FIG. 22 is a flowchart illustrating a flow of a process performed by a handle grip failure alarm processing unit according to the present embodiment.

FIG. 23 is a flowchart illustrating a flow of a process performed by a reference value correction unit according to the present embodiment.

[Explanation of symbols]

 11 and 12 are infrared heart rate sensors, 11a and 12a are light emitting
Parts, 11b and 12b are light receiving parts, 13, 14, and 17 are heartbeat processors.
15 is a signal selecting means, and 16 is a potential heart rate sensor.
16a, 16b are electrodes, 18 is a heart rate data processing hand
Step, 19 is heartbeat arousal degree determination means, 20 is a steering axis, 21 is
A steering angle sensor, 22 is a steering angle data processing means, and 23 is a steering angle data processing means.
Steering arousal level determination means, 24 is a vehicle speed sensor, 25 is a driver's seat,
26 is an alarm means, 27 is a front window, 28, 2
9 is alarm means, 30 is alarm control means, 31 is alarm release switch.
Switch, 32 is a reference value correction unit, 33 is a steering wheel, 3
4 is a handle grip failure alarm means, and 35 is a handle grip failure.
Good alarm processing unit, 36 is a steering column, 37 is a gear tube, 38
Is a drive gear, 39 is a rotating shaft, 40 is a driven gear, and 41 is a
Gears for removing crash, 42 is a vehicle, 43 is a seat bar
, 44 is a side support, 45 is a display, 4
6 is a dozing warning mark, 47 is an instrument panel
Reference numeral 48 denotes an alarm buzzer. D_RHIs the adjacent pole
Slope between heart rate, F_NIIs a normal input determination flag, F_PRIs
Alarm preparation flag, F_RIs the heart rate data hold flag, F_ST
Is the conflict state experienced flag, F_U1Is the first input
Rug, F_U2Is the second input failure determination flag, F_WGIs an alarm
Flag, F_WSIs the awakening degree stable state experienced flag, f is
Cutoff frequency, I_MNIs the minimum pulse interval, I_MXIs the maximum pulse interval
Separation, I_PIs the pulse interval, I_PBIs the reference pulse interval, I_SIs a mark
This interval, L_WIs the alarm level, M is the number of samples to average,
M_AIIs the pole index of the 4-point moving average heart rate, M_HIs the sample
Number, M_LIs the number of samples, M_PIIs the pole index of pole heart rate, N_D
Is the number of heart rate data, N_DAIs the number of effective heart rate data, N_DBIs
Number of adjacent pole heart rate data, N_DEIs based on the potential-type heart rate sensor.
Heart rate data, N_DIIs a heart with an infrared heart rate sensor
Number of beat data, N_P4Is the number of 4-point moving average steering angle data, N
_P15Is the number of 15-point moving average steering angle data, N_SIs the effective steering angle
Number of data, P_A4Is the 4-point moving average steering angle, P_A4-10Is 10
× 4-point moving average steering angle, P_A4-70Is 70x4 moving average
Steering angle, P_{A15 (n)}Is the 15-point moving average steering angle, P_A15-10Is
10 × 15-point moving average steering angle, P_A15-70Is 70 × 15 points
Moving average steering angle, P_S10Is the parameter of the visual steering component range.
TA, P_S70Is also the parameter of the visual steering component range, P_SS10Is the base
Quasi-parameter, P_SS70Also the reference parameter, R_A4Is 4 points
Moving average heart rate, R_A10Is the 10-point moving average heart rate, R_A30Is
30 second average heart rate, R_HIs the heart rate, R_HBIs the reference heart rate,
R_HPIs the extreme heart rate, S is the visual steering component range, S_HIs visual manipulation
Rudder component area, S_LIs the visual steering component range, T_AIs the addition time, T_AL
Is the first addition time, T_ASIs the second addition time, T_BWIs the standard
Alarm switching time, T_CBIs the count of the adjacent pole heart rate timer
Value, T_CDIs the count value of the pole heart rate tilt timer, T_CHIs
The count value of the handle grip alarm switching timer, T_CIIs input
Count value of defective integration timer, T_CPIs a pole heart rate timer
Count value of T _CRIs the heart rate data timer count
Value, T_CSIs the count of the handle grip failure alarm preparation timer
Value, T_CWIs the count value of the alarm switching timer, T_CUIs the degree of arousal
Count value of drop timer, T_HLIs the reference alarm preparation time, T
_RBIs the set time of the adjacent pole heart rate timer, T_RDIs the extreme heartbeat
Set time of number slope timer, T_RHIs a handle grip alarm switch
Timer set time, T_RIIs when the input failure integration timer is set
While T_RPIs the set time of the pole heart rate timer, T_RSIs a hand
Set time of the gripping failure alarm preparation timer, T_RUIs low alertness
Set time of lower timer, T_SIs the subtraction time, T_WLIs an alarm
The first set time of the timer, T_WMIs the second alarm generation timer
Set time, T_WSIs the third set time of the alarm generation timer,
t_PIs the heartbeat pulse detection time, and V is the vehicle speed.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Kawakami 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) References JP-A-3-67727 (JP, A) JP-A-1-131648 (JP, A) JP-A-4-183439 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61B 5/18 A61B 5/0245 B60K 28/06

Claims (1)

(57) [Claims] And 1. A steering angle sensor for detecting a steering angle of the vehicle during traveling, and calculates the frequency distribution of the steering angle signal based on the output of the steering angle sensor, the driver on the basis of visual information
A steering angle data processing means for obtaining a parameter of the driver's steering characteristic by extracting a visual steering component performing steering, and a steering characteristic parameter obtained by the steering angle data processing means being set to a predetermined reference. An arousal level determining device for determining a decrease in arousal level by comparing with a value.