JPH11314534A - Caution ability reduction preventive device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow to decide the fatigue conditions of individual drivers even in a vehicle plural drivers use, and to decide the fatigue condition generated from the driving work accurately. SOLUTION: A driver inputs a driver information from a driver specifying device 1. A running condition detecting device 2 detects the running condition of a vehicle, and outputs a running mode. The electrocardiographic signal of the driver is measured by an electrocardiographic signal detecting device 3, while a sympathetic and parasympathetic nerve activity calculator 4 finds a pulsation interval (RRI) from the electrocardiographic signal at every running mode, so as to calculate the sympathetic and parasynpathetic nerve activity. In an accumulating fatigue condition deciding part 5, this time calculation value and the last time calculation value at the same driver and in the same running mode which is stored in a memory 6 is compared, the accumulated fatigue condition is decided, and it is output to a controller 8. In an awaking level reducing condition deciding part 7, the sudden increasing condition of the pulsation number is decided from the pulsation interval (RRI), and it is ontput. In the controller 8, different sorts of alarm sounds are generated from an alarm generator 9 according to the combination of deciding results, and the oxygen is fed from a specified time oxygen feeding part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing a decrease in caution ability for a vehicle, which prevents a decrease in caution ability in driving according to a fatigue state of a vehicle driver.

[0002]

2. Description of the Related Art As a conventional device for preventing a decrease in caution ability of a vehicle, there is a device using a flicker test device shown in FIG. In this apparatus, first, light whose brightness frequency is controlled by the control unit 31 is supplied from the light source 32 to the driver, and a critical frequency (flicker frequency) at which the driver can see flicker is measured by the flicker frequency measurement unit 33. The fatigue state of the person. The control unit 31 adjusts the air quality state in the vehicle according to the determined fatigue state.
4. However, the driver has to perform a flicker test every time he gets into the vehicle,
Since the determination result of the flicker test depends on the familiarity of the driver, the reliability of the determination result of the fatigue state may be reduced if the test is repeated.

[0003] Accordingly, a vehicle attention prevention ability reduction device using an accumulated fatigue state determination device that measures the driver's pulse data and determines the accumulated fatigue state of the driver from the fluctuation state of the standard deviation of the pulsation interval has been developed. Was done. This is to determine the fatigue state by using the high correlation between the fatigue state and the autonomic nervous system to determine the activity of the autonomic nervous system from the change in the heart beat interval, as shown in FIG. The pulse data of the driver at the time of starting the engine is detected by the heartbeat-equivalent signal detection unit 41, the standard deviation of the pulsation interval is calculated by the pulsation interval standard deviation calculation unit 42, and stored in the memory 44 of the accumulated fatigue state determination unit 43. The pulse data is measured again at the next engine start, the standard deviation of the pulsation interval is obtained, and the result is compared with the previous value stored in the memory 44 to determine the fatigue state. The air quality condition in the vehicle is controlled by the air quality purifying section 46 in accordance with the determined fatigue condition.

[0004]

However, the conventional vehicle attention prevention device does not have means for identifying the driver, so that it can be used only for the judgment on the commercial vehicle in which the driver is identified. In addition, since the pulse data is measured in a situation that is not stable for the driver immediately after starting the engine, the measurement result strongly reflects the activity state of the driver immediately before starting the vehicle, and There is a problem that the reliability of the state determination is poor.

Further, in order to prevent a vehicle accident due to fatigue caused by driving a vehicle for a long time, development of a device for detecting fatigue caused by driving operation is strongly demanded. In this case, since the fatigue state is only measured when the vehicle is started, there has been a problem that the fatigue caused by the driving operation cannot be determined and an appropriate countermeasure cannot be implemented based on the determination result. The present invention has been made in view of the above problems, even in a vehicle used by a plurality of drivers, accurately determines the fatigue state of a running driver, and according to the determination result of the fatigue state, at an appropriate timing, It is an object of the present invention to provide a device for preventing a decrease in caution ability for a vehicle, which can implement a countermeasure.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a driver specifying device for specifying a vehicle driver, a heartbeat equivalent signal detecting device for detecting a driver's heartbeat equivalent signal, and a heartbeat equivalent signal detecting device. A fatigue state determination unit that calculates beat interval data from the detected heartbeat-equivalent signal and determines the fatigue state of the driver identified by the driver identifying device based on the beat interval data; It is assumed that the vehicle has a driving caution ability lowering prevention unit for preventing a performance drop and a control unit for controlling the driving caution ability lowering prevention unit in accordance with the fatigue state determined by the fatigue state determination unit.

The fatigue state determination unit includes a traveling state detecting device for detecting a traveling state of the vehicle, and a heartbeat-equivalent for each of the driver identified by the driver identifying device and the traveling state of the vehicle detected by the traveling state detecting device. A driving unit including a sympathetic parasympathetic activity calculating unit that calculates a sympathetic parasympathetic activity from the beat interval data calculated from the signal, and a storage unit that stores the sympathetic parasympathetic activity calculated by the sympathetic parasympathetic activity calculating unit. Parasympathetic nerve activity calculated by the sympathetic parasympathetic nerve activity calculator for each driver and driving situation specified by the driver identification device, and sympathetic parasympathetic nerve activity in the same driving situation of the same driver stored in the storage unit. It is preferable to have an accumulated fatigue state determination unit that compares the degrees and determines the accumulated fatigue state as the fatigue state. The traveling condition detection device classifies traveling conditions based on information collected by a navigation system and vehicle speed information measured by a vehicle speed sensor. In addition, the fatigue state determination unit may include an awakening degree reduction state determination unit that determines a driver's awakening degree reduction state as the fatigue state based on an instantaneous change in beat interval data calculated from a heartbeat equivalent signal. .

The driving caution ability lowering prevention unit has an alarm generation unit that generates an alarm, and the control unit determines a timing at which the alarm generation unit generates an alarm according to the fatigue state determined by the fatigue state determination unit. Control to make the driver aware of a decrease in attentional ability. The driving caution ability reduction prevention unit has an alarm generation unit that generates an alarm, and the control unit determines the type of alarm generated by the alarm generation unit in accordance with the fatigue state determined by the fatigue state determination unit. It is also possible to control the driver to make the driver aware of the decrease in attention ability. The driving caution ability reduction prevention unit has an oxygen supply unit that supplies oxygen into the vehicle, and the control unit controls an amount of oxygen to be supplied according to the fatigue state determined by the fatigue state determination unit, It may be a device that suppresses a decrease in attentional ability.

[0009] A vehicle surrounding situation detecting section for detecting a situation around the vehicle, a vehicle surrounding situation notifying section for notifying a driver of a detection result detected by the vehicle surrounding situation detecting section, and a fatigue state determined by the fatigue state determining section. , A notification control unit that controls the vehicle surrounding situation notification unit. It is preferable that the notification control unit controls the level of the notification method performed by the vehicle surroundings status notification unit in accordance with the fatigue state determined by the fatigue state determination unit, and compensates for a decrease in the driver's attention ability.

[0010]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing a decrease in caution ability for a vehicle, which prevents a decrease in caution ability in driving according to a fatigue state of a vehicle driver.

[0011]

[Function] The operation of a vehicle is classified as light work, but it requires intermittent recognition and judgment, and mental fatigue accumulates if driving is continued for a long time. Would. When fatigue is accumulated, it becomes difficult to concentrate on driving gradually even in a driving condition requiring a concentrated state, for example, when driving at a speed of 50 km / h or more on a highway. On the contrary, the mental state of concentration always remains, and even in a situation where tension is not required, it is impossible to relax. In this case, for example, even if the vehicle is stopped by a signal or the like while driving, a concentrated state close to running is continued. By utilizing this phenomenon, the fatigue state can be estimated by detecting the driver's concentration state from the beat interval data for each running situation. Also, when the driver's fatigue state worsens and the consciousness awakens, the heart rate is momentarily increased as a result of a conflict with the consciousness that the driver must be awake. The driver in which the heart rate rapid increase state is detected can be regarded as having reduced driving attention ability.

In the device for preventing a decrease in attentional ability for a vehicle according to the present invention, first, a driver specifying device is provided so that a plurality of drivers can specify individual drivers even if the vehicle is driven as required. Thus, the fatigue state of each driver can be determined. Also, by detecting a signal corresponding to the heartbeat of the driver during driving, calculating beat interval data, and determining the fatigue state based on the beat interval data, it is possible to determine the fatigue state caused by the driving work, Depending on the determined fatigue state, for example, to control the timing and type of alarm to generate a warning sound from the warning generation unit of the driving caution ability reduction prevention unit,
Alternatively, the amount of oxygen supplied from the oxygen supply unit that supplies oxygen to the inside of the vehicle is controlled to prevent a decrease in driving caution ability.

Based on the information collected by the navigation system and the vehicle speed information detected by the vehicle speed sensor, the driving condition is classified into, for example, a vehicle speed, a driving on a general road or a driving on a highway, and the vehicle is stopped. Pulsation interval data detected under stable driving conditions, such as a `` stop mode '' or a `` high-speed mode '' running at a speed higher than a predetermined speed on a highway, shows a correlation with the driver's concentration state and relaxed state. By calculating the sympathetic parasympathetic nervous activity known to be present and comparing it with the sympathetic parasympathetic nervous activity of the same driver in the same driving situation, it is possible to accurately determine the accumulated fatigue state as the fatigue state. it can.

For example, as shown in FIG. 16, when the vehicle travels in a traveling condition of traveling 1, stopping 1, traveling 2, stopping 2, and traveling 3, traveling 1 travels on an expressway at an average section speed of 60 km / km.
It is assumed that the vehicle travels at a section average speed of 20 km / h because the vehicle travels on a high-congested road in a city area, and travels on the expressway again at a section average speed of 65 km / h. At this time, the traveling states 1 and 3 are traveling states that require the same concentration state, and if the fatigue state is not advanced, the same concentration state as the traveling state 1 is maintained in the traveling state 3. Is done. Further, the relaxed state at the stop 1 and the state of the stop 2 are maintained. However, as a result of traveling on a road with a little traffic congestion in traveling 2, if the fatigue state is getting worse, the concentration state in traveling 3 is lower than that in traveling 1, and in stop 2, it is more difficult to relax than in stop 1. Therefore, by comparing the sympathetic parasympathetic nervous activity calculated from the pulsation interval data and measuring the change in the concentration state or the relaxed state, the accumulated fatigue state of the driver can be determined.

Further, a state in which the beat interval is sharply reduced, that is, a state in which the heart rate instantaneously increases, is detected from the beat interval data calculated from the heartbeat equivalent signal, and a state in which the driver's arousal level is reduced is detected. By controlling the driving caution ability lowering prevention unit, for example, it is possible to perform a preventive measure such as issuing an alarm sound or supplying oxygen at an appropriate timing before the driving ability limit is reached.

According to the fatigue state determined by the fatigue state determination unit, for example, a vehicle surrounding state notification unit that notifies a driver of a detection result detected by a vehicle surrounding state detection unit such as a surrounding vehicle approach detection unit. By controlling the level of the notification method to be performed, for example, by gradually increasing the volume of the alarm sound, even if the driver's fatigue state progresses and the attention ability is reduced, the driver can reliably approach the surrounding vehicles. Can be recognized.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to examples. FIG. 1 is a diagram showing the configuration of the first embodiment. Here, while measuring and calculating the sympathetic and parasympathetic nervous activity of a specific driver, and comparing with the measurement value of the previous measurement for each running condition of the vehicle, the accumulated fatigue state is determined,
By detecting a sudden increase in the heart rate of the driver, the driver's heart rate instantaneously increases, thereby detecting a warning sign that the driver is approaching the driving ability limit and generating an alarm or supplying oxygen to the driver to be cautious. Is prevented from decreasing.

A device for preventing a decrease in attentional ability for a vehicle includes a driver specifying device 1 for specifying a driver at the time of measurement from a plurality of registered drivers, and a driving condition detecting device for detecting a driving condition of the vehicle. 2, an electrocardiographic signal detecting device 3 by a potential type detection method as a heartbeat equivalent signal detecting device for detecting a driver's heartbeat equivalent signal, and a pulse from the driver's electrocardiographic signal detected by the electrocardiographic signal detecting device 3. Sympathetic parasympathetic activity calculating unit 4 that calculates the moving interval data and obtains the sympathetic parasympathetic activity from the beat interval data, the above-mentioned driver identifying device 1, running condition detecting device 2, and sympathetic parasympathetic activity calculating unit 4. Awakening degree detecting state for detecting the presence or absence of a heart rate sudden increase state in which the heart rate instantaneously increases from the beat interval data calculated by the accumulated fatigue state determining unit 5 and the sympathetic parasympathetic activity calculating unit 4 connected to Judgment unit 7 And accumulated fatigue state determining section 5 and the awareness decrease state determining unit 7 is connected to the control unit 8, and a warning generating unit 9 and the oxygen supply unit 10 is controlled by the control unit 8.

The driver identification device 1 has a touch panel type switch arranged near the front panel, and different drivers are registered in advance for each switch. When the driver presses a registered switch, the driver information is output to the accumulated fatigue state determination unit 5. Position information measured by a navigation system (not shown) and vehicle speed information detected by a vehicle speed sensor (not shown) are input to the driving situation detecting device 2, the driving mode is calculated, the sympathetic / parasympathetic nerve activity calculating unit 4 and the accumulated fatigue state Output to the determination unit 5. The electrocardiographic signal detection device 3 collects an electrocardiographic signal from the driver's hand using an electrode installed on the steering wheel and outputs the signal to the sympathetic / parasympathetic nerve activity calculator 4.

The sympathetic parasympathetic activity calculating section 4 calculates the rhythm time interval R based on the electrocardiogram signal collected from the driver.
Detects RI (RR interval) data, RR
The activity of the sympathetic parasympathetic nerve is calculated from the normalized variance RRV of the I data. The accumulated fatigue state determination unit 5 includes a storage unit 6, and accumulates the driver identified by the driver identification device 1 from the outputs of the driver identification device 1, the driving situation detection device 2, and the sympathetic parasympathetic activity calculation unit 4. The fatigue state is determined, and the determination result is output to the control unit 8. The arousal level reduction state determination unit 7 inputs the pulsation interval RRI calculated by the sympathetic / parasympathetic nervous activity calculation unit 4 and monitors the fluctuation of the pulsation interval. It captures the instantaneously increasing heart rate rapidly increasing state and outputs it to the control unit 8.

In the control unit 8, the accumulated fatigue state determination unit 5
The alarm generator 9 and the oxygen supply unit 10 are controlled according to the determination result of the arousal level reduction state determination unit 7. The alarm generation unit 9 is provided in the vehicle, and generates an alarm in which the type and loudness of the sound changes stepwise. The oxygen supply unit 10 is installed so as to be able to supply oxygen from an air outlet of the air conditioner, and supplies oxygen to the vehicle for a predetermined time under the control of the control unit 8.

Next, the operation of the vehicle attention prevention device will be briefly described. The driver presses a previously registered switch on the driver identification device 1 before starting driving the vehicle. The traveling state detecting device 2 first determines whether the vehicle is traveling on a general road or a highway from the position information by the navigation system, and then determines the current traveling state from the vehicle speed information detected by the vehicle speed sensor, The driving mode is output to the sympathetic parasympathetic activity calculating section 4 and the accumulated fatigue state determining section 5.

When the driver grips the steering wheel, the driver's electrocardiographic pulsation signal R-wave as shown in FIG. 2 is measured by the electrodes of the electrocardiographic signal detection device 3 provided on the steering wheel, and sympathetic and parasympathetic. It is output to the neural activity calculating section 4. The sympathetic parasympathetic activity calculating unit 4 accumulates RRI data for 30 seconds after calculating the pulsation interval RRI. However, if data that greatly deviates from the RRI value calculated immediately before is detected, the Accumulated beat intervals RRI are calculated by removing accumulated RRI data including RRI data.

Next, a normalized variance RRV and an average heart rate BEAT expressed by the following equation are calculated from the beat interval RRI.

(Equation 1) It has been experimentally confirmed that the sympathetic parasympathetic activity and the degree of variation in the RRI data have a close correlation.
Here, a normalized variance R is used as an index representing this variation.
RV and average heart rate BEAT are used. RRV-BEAT is the calculated normalized variance RRV and average heart rate BEAT.
It is output to the accumulated fatigue state determination unit 5 as two-dimensional data.

The accumulated fatigue state determination unit 5 stores the center of gravity of the RRV-BEAT two-dimensional data measured this time and the storage unit 6
Is compared with the position of the center of gravity of the previous measurement result in the same driver and the same traveling condition stored in the memory. FIG. 3 is a diagram showing the relationship between the normalized variance RRV and the average heart rate BEAT. The horizontal axis represents the normalized variance RRV, and the vertical axis represents the average heart rate BEAT.
AT is displayed. Then, the normalized variance RRV indicates that the average heart rate BEAT is more concentrated toward the left as it goes to the left. Basically, a healthy person who is not tired is driving at high speed, and there is a clear difference in the reaction between the `` high speed mode '' that requires tension and the `` stop mode '' where it is stopped. is there.

That is, in the case of a healthy person, as shown in FIG. 3A, the distribution areas of the RRV-BEAT two-dimensional data in the "high-speed mode" and in the "stop mode" are located far from each other. Distributed. If the distribution area is concentrated in the “high-speed mode”, the distribution area in the “high-speed mode” is located at the upper left of the distribution area in the “stop mode” where the degree of concentration is high. this is,
This is a normal response considering the activity of the sympathetic parasympathetic nerve. On the other hand, a person in need of attention who is in a fatigued state cannot maintain an appropriate concentration state as shown in FIG. As shown in ()), when stopping, a phenomenon that the user cannot relax sufficiently occurs. In the accumulated fatigue state determination unit 5, the specified driver's
By comparing the position of the center of gravity of the RRV-BEAT two-dimensional data for each driving situation, the accumulated fatigue state can be determined as a “normal region”,
The information is classified into four areas of an “attention area”, a “dangerous area”, and an “unknown area” where an electrocardiographic signal cannot be detected, and is output to the control unit 8.

However, the above determination of the accumulated fatigue state does not immediately indicate the driving capability limit of the driver. Driving ability limits also have individual differences, and even the same driver may differ depending on physical condition and the like. In general, as a process that reaches the driving ability limit during driving, a decrease in arousal level during driving operation can be seen, but when the arousal level decreases while driving the vehicle, a characteristic that is different from when the normal arousal level decreases A condition arises. This is the result of a conflict with the driver's awareness of the need to wake up when the driver's arousal level decreases, as shown by the arrow in FIG. It is a phenomenon. It is considered that the driver in which the rapid increase in heart rate has a near limit of driving ability.

However, even when the degree of awakening is not reduced, a similar rapid increase in heart rate occurs even when the driver is looking aside. It is possible to more appropriately grasp the driving capability limit of the driver. The arousal degree reduced state determination unit 7 detects this rapid increase in heart rate and outputs it to the control unit 8. The control unit 8 combines the accumulated fatigue state determination result as shown in FIG. 5A and the detection result of the heart rate rapid increase state as shown in FIG. The type of alarm sound and the supply time of oxygen supplied from the oxygen supply unit 10 are determined.

Next, the flow of operation in the first embodiment of the present invention will be described in more detail. The driver presses a previously registered switch on the driver identification device 1 before starting driving the vehicle. The traveling condition detecting device 2 determines whether the vehicle is traveling on a general road,
First, it is determined whether the vehicle is traveling on a highway, and then the current traveling state is determined from the vehicle speed information detected by the vehicle speed sensor, and output as a traveling mode to the sympathetic parasympathetic nerve activity calculating unit 4 and the accumulated fatigue state determining unit 5. I do.

When the vehicle is stopped on a traffic light or a traffic jam, a "stop mode" is set to measure the state when the driver is resting while driving on a general road. In particular,
The one-minute section average speed in advance is calculated every minute, and if the section average speed is 0 Km / h, the “stop mode” is output to the accumulated fatigue state determination unit 5. While driving on a general road,
Since the driving state changes frequently, the pulsation interval RRI greatly changes at times other than when the vehicle is not stopped, and the comparison becomes difficult. Therefore, the traveling mode is not output.

When the vehicle is traveling at a high speed, the "high speed mode" is output in order to measure a state in which a constant driving state continues while traveling on the highway. In particular,
The section average speed for two minutes is calculated in advance, and if the section average speed is greater than 50 km / h, the “high-speed mode” is output to the accumulated fatigue state determination section 5. When the vehicle is traveling at a low speed due to light traffic or the like, the traveling mode frequently changes and the comparison becomes difficult as in the case of traveling on a general road, so that the traveling mode is not output. If it is stopped, the "stop mode" is output.

Next, the flow of operation from the detection of the driver's electrocardiographic signal to the calculation of the sympathetic parasympathetic nervous activity will be described with reference to the flowchart shown in FIG. In step 101, the electrocardiogram signal of the driver is measured by the electrocardiogram signal detection device 3,
It is output to the sympathetic parasympathetic activity calculating section 4. In the case of an ECG signal, it is necessary to attach electrodes to the body, but here, since accurate waveform diagnosis for medical use is not intended, the ECG signal of the driver is sent from the electrode attached to the steering wheel. Is measured.

In step 102, the sympathetic parasympathetic activity calculating section 4 samples the electrocardiographic signal at 100 Hz or higher and sequentially captures it as a heartbeat equivalent signal. Next, in step 103, a heartbeat-equivalent signal from which undesired signals such as noise have been removed is obtained by filtering or thresholding using a bandpass filter or a matched filter.
In step 104, a beat interval RRI (R-R interval), which is a beat interval, is detected from the heartbeat equivalent signal. However, since the RRI data originally fluctuates, the RRI data must be irregularly sampled in time series. However, if necessary, regular sampling is performed in time series by interpolation. It is also possible to use a simple sampling. In step 105, the detected RRI data is stored.

At step 106, the time interval RRI of the beat
It is checked whether the data is within a predetermined range. Here, when detecting the new data RRI (1), the immediately preceding data RRI (0) is referred to, and the (1/2) R
A range from RI (0) to (3/2) RRI (0) is set as a detection range. If the pulsation is lost due to arrhythmia or a detection error, the RRI becomes about twice the normal value, so that it can be detected by this check. Also, due to pulses due to electrical noise,
Even when incorrect RRI data is detected, it can be detected by this check. That is, when the RRI (1) is within the above range, the process directly proceeds to step 108. When the RRI (1) is not within the above range, it is regarded that the defect data has been detected, and
Proceeding to step 107, the stored RRI data is deleted, and the process returns to step 102 to perform new sampling.

In step 108, it is determined whether or not the accumulated RRI data exists for 30 seconds. If the time is not enough for 30 seconds, the process returns to step 102 to continue sampling, and the steps from step 102 to step 10 are repeated until continuous RRI data for 30 seconds is accumulated.
Repeat up to 8. When the RRI data for 30 seconds has been accumulated, the process proceeds to step 109. First step 1
In 09, the normalized variance RRV and the average heart rate BEAT are obtained from the RRI data for 30 seconds every 15 points by one point shift.
Is calculated. Here, the reason why the analysis section is shifted by one point width is that, when analyzing the RRI data in time series, it is possible to perform the analysis in a point-by-point manner in the most detailed manner. Next, in step 110, the relationship between the normalized variance RRV and the average heart rate BEAT is obtained as two-dimensional data on a two-dimensional plane, and output to the accumulated fatigue state determination unit 5 as an RRV-BEAT two-dimensional data set.

Next, the flow of operation in the accumulated fatigue state judging section 5 will be described with reference to the flowchart shown in FIG.
First, in step 201, driver identification information is input from the driver identification device 1. In step 202, the RRV-BEAT two-dimensional data set is input from the sympathetic parasympathetic activity calculating unit 4. In step 203, the driving mode is input from the driving situation detecting device 2. In step 204,
In step 202, the position of the center of gravity of the RRV-BEAT two-dimensional data set input is calculated.

In step 205, it is determined whether or not the center of gravity of the RRV-BEAT two-dimensional data set of the same driver in the same driving mode is stored in the storage unit 6.
If it is stored, the process proceeds to step 206. If it is not stored, this time is the first measurement, and there is no value to be compared for the determination of the fatigue state. Therefore, it cannot be determined,
The process proceeds from step 205 to step 210, in which the current measured value is stored in the storage unit 6 as the center of gravity in combination with the driver identification information and the driving mode. In step 206,
The traveling mode is determined. When the traveling mode is the "stop mode", the process proceeds to step 207. When the traveling mode is the "high-speed mode", the process proceeds to step 208.

In step 207, the center of gravity of the RRV-BEAT two-dimensional data set in the "stop mode" measured this time is set to S (Sr, Sb), and the same driver stored in the storage unit 6 in the "stop mode". The center of gravity position of the RRV-BEAT two-dimensional data set measured last time is defined as the previous center of gravity position SA (SAr, SAb), and as shown in FIG. 8A, the center of gravity position S (Sr, Sb) and the previous center of gravity position SA
The relationship of (SAr, SAb) is examined. First, the center of gravity position S
If Sr and Sb of (Sr, Sb) are within 0.8SAr <Sr Sb <1.2SAb, the measured driver is in a state close to the previous relaxed state when the measured driver was in the "stop mode". Yes, the fatigue state is determined to be the “normal region”.

Next, Sr at the center of gravity position S (Sr, Sb),
If Sb is in the range of 0.6SAr <Sr ≦ 0.8SAr or 1.2SAb ≦ Sb <1.4SAb, it is a cautionary state deviating from the previous relaxed state, and the fatigue state is a “caution region”. Is determined.

Next, Sr of the center of gravity position S (Sr, Sb),
If Sb is within the range of Sr ≦ 0.6SAr 1.4SAb ≦ Sb, the fatigue state is severe, the state is dangerous, and it is determined that the area is “dangerous area”. After the end of the determination, the process proceeds to step 209, and outputs the determination result to the control unit 8.

In step 208, the center of gravity of the RRV-BEAT two-dimensional data set in the “high-speed mode” measured this time is set to H (Hr, Hb), and the same driver stored in the storage unit 6 in the “stop mode” Assuming that the center of gravity of the previously measured RRV-BEAT two-dimensional data set is the previous center of gravity HA (HAr, HAb), as shown in FIG. 8B, the center of gravity H (Hr, Hb) and the previous center of gravity HA
The relationship between (HAr, HAb) is examined. First, the center of gravity position H
If Hr, Hb of (Hr, Hb) is within the range of Hr <1.2SHr 0.8SHb <Hb, the measured driver is in a state close to the previous tension state when the measured driver is in the “high-speed mode”. , The fatigue state is determined to be the “normal region”.

Next, Hr at the center of gravity H (Hr, Hb),
If Hb is in the range of 1.2HAr ≦ Hr <1.4HAr 0.6HAb <Hb ≦ 0.8HAb, it is a cautionary state deviating from the previous tension state, and the fatigue state is “caution zone”. Judge that there is

Next, Hr at the center of gravity H (Hr, Hb),
If Hb is in the range of 1.4HAr ≦ Hr Hb ≦ 0.6HAb, the fatigue state is severely dangerous, and it is determined that the fatigue state is “dangerous area”. After the end of the determination, the process proceeds to step 209, and outputs the determination result to the control unit 8. After completion of the determination, the process proceeds to step 210, where the position of the center of gravity calculated in step 207 or 208 is stored in the storage unit 6 in combination with the driver identification information and the driving mode, and step 201
Return to and wait for input of the next RRV-BEAT two-dimensional data set.

Next, using the flowchart shown in FIG.
The operation of the arousal degree reduced state determination unit 7 will be described. Step 3
In step 01, the pulsation interval RRI is input from the sympathetic parasympathetic activity calculating unit 4. In step 302, as shown in FIG. 10, the currently detected beat interval RRI (1)
The beat intervals RRI (0) detected before the current time are compared. If the beat interval RRI (1) is smaller than the beat interval RRI (0) × 0.8, the heart rate instantaneously increases. It is considered that the heart rate is rapidly increasing, and the process proceeds to step 303. If the pulsation interval RRI (1) is equal to or greater than the pulsation interval RRI (0) × 0.8, the process returns to step 301, waits for the input of the next pulsation interval RRI, and repeats steps 301 and 302. In step 303, the controller 8 outputs to the control section 8 that the sudden increase in the heart rate has been detected.

Next, the operation of the control unit 8 will be described. Control unit 8
Then, the alarm sound generation unit 9 and the oxygen supply unit 10 are controlled based on the determination result input from the accumulated fatigue state determination unit 5 and the detection result of the arousal level reduction state determination unit 7. (A) of FIG.
Shows the control state of the alarm sound, and (b) shows the control of the oxygen supply time. First, as shown in the upper part of FIG.
When the determination result enters the “attention area” from another area, the alarm generation unit 9 issues a low volume attention alert for 30 seconds. At the same time, as shown in the upper part of FIG. 11B, oxygen is supplied from the oxygen supply unit 10 into the vehicle for 5 minutes. Similarly, when the vehicle enters the “danger zone”, a high-volume caution alarm is generated for 30 seconds, and oxygen is supplied for 10 minutes. When entering the “unknown area”, no alarm sound is generated, but oxygen is supplied for 5 minutes just in case.

Next, the operation when a rapid increase in the heart rate is detected will be described. When the determination result input from the accumulated fatigue state determination unit 5 is in the “normal region”, when the heart rate sudden increase state is detected, as shown in the lower part of FIG. A caution alarm is generated for 30 seconds, and at the same time, oxygen is supplied for 5 minutes as shown in the lower part of FIG. If a rapid increase in heart rate is detected in the "attention area", a high volume alert is issued for 30 seconds and oxygen is supplied for 10 minutes. Also, in the "danger zone",
If a sudden increase in the heart rate is detected, a danger alarm is issued for 30 seconds so that the driver can clearly recognize the danger, and oxygen is released for 1 second.
Supply for 5 minutes. If a sudden increase in the heart rate is detected in the "unknown region", a loud volume warning is issued for 30 seconds, and oxygen is supplied for 10 minutes.

As described above, according to the first embodiment, first, by providing the driver identifying device 1, even if a plurality of drivers drive the vehicle as needed, individual drivers And the fatigue state of each driver can be determined. In addition, pulsation interval data is calculated from electrocardiographic signals detected in a stable running state such as a “stop mode” detected by the running state detection device 2 or a “high speed mode” running at high speed, and sympathetic sub-sympathy is calculated. By calculating the neural activity and comparing it with the previous measured sympathetic and parasympathetic nerve activity in the same driving situation of the same driver, the fatigue status can be compared in time series, so the change of the driver's fatigue status Can be accurately determined.

Further, the arousal degree lowering state judging section 7 detects a state in which the pulsation interval is sharply reduced, that is, a state in which the heart rate is momentarily increased, from the pulsation interval data calculated from the heartbeat equivalent signal. A low arousal level is detected.
Then, in the control unit 8, according to the determination result in the accumulated fatigue state determination unit 5 and the detection result in the awakening degree reduced state determination unit 7,
The type and volume of the alarm sound generated from the alarm generation unit 9 are controlled at appropriate timing, and the oxygen supply time from the oxygen supply unit 10 that supplies oxygen into the vehicle is controlled. For this reason, before the driver's fatigue state reaches the driving caution ability limit, preventive measures such as issuing a danger warning sound to notify the driver of the danger state and supplying sufficient oxygen are implemented at appropriate timing. As a result, the driver's caution ability can be prevented from lowering.

In the above embodiment, the calculated degree of sympathetic / parasympathetic nerve activity was compared with the previous measured value.
The present invention is not limited to this, and may be compared with the average value of the degree of calculation of the sympathetic and parasympathetic nervous activity calculated in the same driving situation of the same driver. In this case, the determination of the accumulated fatigue state is performed by repeating the measurement. The accuracy is improved. In addition, in the determination of the fatigue state, the determination result of the accumulated fatigue state and the determination result of the reduced arousal level were used, but the present invention is not limited to this. I just need.

FIG. 12 is a view showing a second embodiment of the present invention. In this method, the result of the fatigue state determination is also used for vehicle surrounding detection. The notification control unit 11 includes:
As with the control unit 8, the determination result of the accumulated fatigue state determination unit 5 and the detection result of the awakening degree reduction state determination unit 7 are output. When another vehicle approaches within 50 m around the vehicle, the notification control unit 11 outputs a vehicle detection signal to the notification control unit 11, and a three-way forward detection unit 12.
m, a pedestrian detection unit 1 that outputs a pedestrian detection signal to the notification control unit 11 when it detects that a pedestrian is within
3, an alarm generating unit 14, a fog lamp 15, and an instrument panel icon display unit 16 are connected. Other configurations are the same as those of the first embodiment shown in FIG. In addition,
The surrounding vehicle approach detection unit 12 and the pedestrian detection unit 13 constitute a vehicle surrounding situation detection unit of the invention, and the alarm generation unit 14, the fog lamp 15 and the icon display unit 16 constitute a vehicle surrounding situation notification unit of the invention.

Next, the operation of the notification control section 11 will be described. In the notification control unit 11, when a vehicle detection signal is input from the surrounding vehicle approach detection unit 12, based on the determination result input from the accumulated fatigue state determination unit 5 and the detection result of the awakening degree reduction state determination unit 7, The level of the notification method when the pedestrian detection signal is input from the pedestrian detection unit 13 is controlled stepwise.

First, a description will be given of a notification method when a vehicle detection signal is input when a rapid heart rate increase state is not detected. As shown in the upper part of FIG. 13A, when the determination result input from the accumulated fatigue state determination unit 5 is the “attention area”, the alarm generation unit 14 generates a low volume alarm sound. Similarly, in the case of the “dangerous area”, a middle volume alarm sound is generated. In the case of the “unknown area”, a low volume alarm sound is generated.

When the sudden increase in the heart rate is detected, the control shown in the lower part of FIG. 13A is performed for a predetermined time after the detection. That is, when the determination result input from the accumulated fatigue state determination unit 5 is in the “normal region”, the alarm generation unit 14 generates a low volume alarm sound. Similarly, in the case of the "attention area", a middle volume alarm sound is generated. In the case of the “dangerous area”, a high volume alarm sound is generated, and in the case of the “unknown area”, a medium volume alarm sound is generated.

Next, a description will be given of a notification method when a pedestrian detection signal is input when a rapid heart rate increase state is not detected. As shown in the upper part of FIG. 13B, when the determination result input from the accumulated fatigue state determination unit 5 is the “attention area”, the fog lamp 15 is turned on so that the presence of the pedestrian stands out. . In the case of the "danger area", the fog lamp 15 is turned on, and a display indicating the presence of the pedestrian is also displayed on the icon display section 16, to call the driver's attention. In the case of the "unknown area", the fog lamp 15 is turned on just in case.

When the rapid increase in the heart rate is detected, the control shown in the lower part of FIG. 13B is performed for a predetermined time after the detection. That is, in the case of the “normal region”, the fog lamp 15 is turned on. "Attention area"
In the case of, the fog lamp 15 is turned on, and a display indicating the presence of the pedestrian is also performed on the icon display unit 16. In the case of the "danger zone", in addition to turning on the fog lamp 15 and displaying an icon, an alarm sound is generated from the alarm generation unit 14,
Remind the driver not to overlook the pedestrian. In the case of the “unknown area”, the fog lamp 15 is turned on and an icon is displayed just in case. Other operations are the same as in the first embodiment.

As described above, in the present embodiment, the surrounding vehicle approach detection unit 12 and the pedestrian detection unit 13 perform the operations based on the determination result of the accumulated fatigue state determination unit 5 and the detection result of the awakening degree reduction state determination unit 7. By controlling the level of the method of notifying the detected result to the driver stepwise, in addition to the effect of the first embodiment, even if the driver's fatigue progresses and the attention ability is reduced, it is ensured. The driver can recognize the approach of the surrounding vehicle and the presence of the pedestrian.

[0057]

In the vehicular caution ability reduction prevention device according to the present invention, first, by providing a driver identification device, a plurality of drivers can control individual drivers even if the vehicle is driven as required. It is possible to identify and determine the fatigue state of each driver. In addition, by providing a running situation detection device, the sympathetic and parasympathetic nerve activity is calculated from beat interval data detected in a stable running situation such as a "stop mode" or a "high speed mode" running at a high speed. Since the accumulated fatigue state can be determined by comparing with the sympathetic and parasympathetic nervous activity of the same driver under the same running condition, the accumulated fatigue state caused by the driving operation during running can be determined. In addition, depending on the determined fatigue state, for example, the type and volume of an alarm sound generated from an alarm generation unit, which is a driving caution ability reduction prevention unit, can be controlled at an appropriate timing, or an oxygen supply that supplies oxygen to the inside of the vehicle. By controlling the oxygen supply time from the unit, it is possible to prevent a decrease in driving caution ability. Therefore, even in a vehicle used by a plurality of drivers, the fatigue state of the running driver can be accurately determined, and a countermeasure can be implemented at an appropriate timing according to the determination result of the fatigue state.

Further, a state in which the pulse interval sharply decreases, that is, a state in which the heart rate increases instantaneously, is detected from the pulse interval data calculated from the heartbeat equivalent signal, and a state in which the driver's arousal level is reduced is detected. By controlling the driving caution ability lowering prevention unit based on the result, it is possible to execute a preventive measure such as issuing an alarm sound or supplying oxygen at an appropriate timing before the driving ability limit is reached. In addition, according to the fatigue state determined by the fatigue state determination unit, for example, a notification method performed by a vehicle surrounding state notification unit that notifies a driver of a detection result detected by a vehicle surrounding state detection unit such as a surrounding vehicle approach detection unit. For example, by gradually increasing the volume of the alarm sound in a stepwise manner, the driver's fatigue state progresses, and the driver can be surely aware of the surroundings of the vehicle even if his / her attention is reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a beat interval in an electrocardiographic waveform.

FIG. 3 is a diagram illustrating a change in a two-dimensional distribution of a normalized heartbeat rate and an average heart rate according to the presence or absence of a fatigue state.

FIG. 4 is an explanatory diagram of a heart rate.

FIG. 5 is a diagram illustrating an accumulated fatigue state and a rapidly increasing heart rate state in the first embodiment.

FIG. 6 is a flowchart showing a flow of an operation for calculating a sympathetic parasympathetic nerve activity from an electrocardiographic signal in the first embodiment.

FIG. 7 is a flowchart illustrating a flow of a procedure for determining an accumulated fatigue state in the first embodiment.

FIG. 8 is a diagram illustrating an example of determining the accumulated fatigue state in the first embodiment.

FIG. 9 is a flowchart illustrating a flow of an operation of detecting a rapidly increasing heart rate state from an electrocardiographic signal in the first embodiment.

FIG. 10 is a diagram showing a beat interval in an electrocardiographic waveform.

FIG. 11 is a diagram for explaining an alarm generation and oxygen supply operation in the first embodiment.

FIG. 12 is a block diagram illustrating a configuration of a second exemplary embodiment of the present invention.

FIG. 13 is a diagram illustrating an alarm generation operation when a nearby vehicle approaches and a pedestrian is detected in the second embodiment.

FIG. 14 is a block diagram showing a configuration of a conventional example.

FIG. 15 is a block diagram showing a configuration of another conventional example.

FIG. 16 is a diagram illustrating an example of division of a traveling state.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Driver specifying device 2 Running condition detecting device 3 Electrocardiographic signal detecting device 4 Sympathetic / parasympathetic nervous activity calculating unit 5, 43 Accumulated fatigue state determining unit 6 Storage unit 7 Low arousal degree determining unit 8, 31, 45 Control unit 9 , 14 Alarm generation unit 10 Oxygen supply unit 11 Notification control unit 12 Surrounding vehicle approach detection unit 13 Pedestrian detection unit 15 Fog light 16 Icon display unit 32 Light source 33 Flicker frequency measurement unit 34, 46 Air quality purification unit 41 Heart rate equivalent signal detection unit 42 beat interval standard deviation calculator 44 memory

Claims (9)

[Claims] 1. A driver identification device for identifying a vehicle driver, a heartbeat equivalent signal detection device for detecting a heartbeat equivalent signal of a driver, and beat interval data from a heartbeat equivalent signal detected by the heartbeat equivalent signal detection device. A fatigue state determination unit that determines the fatigue state of the driver specified by the driver specifying device based on the beat interval data, An attentiveness reduction device for a vehicle, comprising: a prevention unit; and a control unit that controls the driving attentional performance decrease prevention unit according to the fatigue state determined by the fatigue state determination unit. 2. The fatigue state determination unit includes: a traveling state detection device that detects a traveling state of a vehicle; and a driver identified by the driver identification device and a traveling state of the vehicle detected by the traveling state detection device. A sympathetic parasympathetic activity calculating unit for calculating the sympathetic parasympathetic activity from the beat interval data calculated from the heartbeat-equivalent signal; and a memory for storing the sympathetic parasympathetic activity calculated by the sympathetic parasympathetic activity calculating unit. A sympathetic parasympathetic activity calculated by the sympathetic parasympathetic activity calculating unit for each of the driver and the driving situation specified by the driver specifying device, and the same driver stored in the storage unit. The low attentional ability for a vehicle according to claim 1, further comprising an accumulated fatigue state determination unit that compares the sympathetic parasympathetic nervous activity in a running situation and determines the accumulated fatigue state as the fatigue state. Bottom prevention device. 3. The vehicle attention deteriorating system according to claim 2, wherein the driving situation detecting device classifies the traveling situation based on information collected by a navigation system and vehicle speed information measured by a vehicle speed sensor. Prevention device. 4. The wakefulness state determination unit that determines a wakefulness state of a driver as the fatigue state based on an instantaneous change in beat interval data calculated from a heartbeat equivalent signal. Claim 1, characterized by having
4. The device for preventing a decrease in caution ability for a vehicle according to 2 or 3. 5. The driving caution ability lowering prevention unit includes an alarm generation unit that generates an alarm, and the control unit controls the alarm generation unit according to the fatigue state determined by the fatigue state determination unit. 3. The method according to claim 1, further comprising: controlling a timing at which an alarm is generated so that the driver recognizes a decrease in attention ability.
5. The device for preventing a decrease in caution ability for a vehicle according to 3 or 4. 6. The driving caution ability lowering prevention unit includes an alarm generation unit that generates an alarm, and the control unit is configured to control the alarm generation unit according to the fatigue state determined by the fatigue state determination unit. 2. The method according to claim 1, wherein the type of the generated alarm is controlled in a stepwise manner so that the driver is made aware of a decrease in attentional ability.
6. The device for preventing a decrease in caution ability for a vehicle according to 2, 3, 4, or 5. 7. The driving caution ability lowering prevention unit includes an oxygen supply unit that supplies oxygen to the interior of the vehicle, and the control unit supplies the oxygen to be supplied according to the fatigue state determined by the fatigue state determination unit. 7. The apparatus for preventing a decrease in the attention ability of a vehicle according to claim 1, wherein the amount is controlled to suppress the decrease in the attention ability of the driver. 8. A vehicle surrounding situation detecting section for detecting a situation around the vehicle, a vehicle surrounding situation notifying section for reporting a detection result detected by the vehicle surrounding situation detecting section to a driver, and a judgment made by the fatigue state judging section. 8. The vehicle according to claim 1, 2, 3, 4, 5, 6, or 7, further comprising a notification control unit that controls the vehicle surrounding state notification unit according to the fatigue state. apparatus. 9. The notification control unit controls a level of a notification method performed by the vehicle surroundings status notification unit according to the fatigue state determined by the fatigue state determination unit, and compensates for a decrease in a driver's attention ability. 9. The apparatus for preventing a decrease in attentional ability of a vehicle according to claim 8, wherein