JP2009293996A - Driver's fatigue degree estimation apparatus and driver's fatigue degree estimation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driver's fatigue degree estimation apparatus and a driver's fatigue degree estimation method which can accurately determine whether or not a driver has gotten fatigued with a cost increase reduced and can detect the fatigue of a driver accurately. <P>SOLUTION: The driver's fatigue degree estimation apparatus 100 takes a fatigue reducing action for a driver when continuous driving hours exceed acceptable driving hours. The apparatus comprises: a fatigue map storage means 13 for storing a fatigue map in which high-fatigue areas are stored by area; a fatigue-degree calculation means 22 for calculating a fatigue degree in accordance with high-fatigue driving hours during which the driver has driven in a high-fatigue area determined with reference to the fatigue map; a standard change means 23 for changing the acceptable driving hours in accordance with the fatigue degree calculated by the fatigue-degree calculation means 22; and a determination means 24 for determining that it is the timing for taking the fatigue reducing action for the driver when the continuous driving hours exceed the acceptable driving hours. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driver fatigue level estimation device and a driver fatigue level estimation method for estimating fatigue of a driver of a vehicle.

  In general, a guideline is provided for continuous driving time so that driver fatigue does not adversely affect vehicle operation. For example, when driving continuously for 2 to 4 hours, it is recommended to take a rest. In order to notify the driver that it is time to take a rest, for example, the navigation device can provide a message that prompts the user to take a rest with an image and a sound every predetermined time.

  Since the driver does not always drive during the predetermined time, an index for more accurately grasping the driver's fatigue has been proposed (for example, see Patent Document 1). Patent Document 1 describes a continuous operation warning device that counts only the time during which the vehicle is traveling as the continuous operation time.

  However, although continuous operation time is a factor that greatly affects driver fatigue, it is known that driver fatigue does not depend only on continuous operation time. About this point, the mental state detection apparatus which detects a driver | operator's fatigue | exhaustion using physiological data is proposed (for example, refer patent document 2). The mental state detection device described in Patent Document 2 estimates the driver's fatigue by multiplying information such as the travel duration and travel road information acquired from the navigation device by the measured heart rate of the driver.

In addition, a navigation device that predicts driver fatigue based on the number of traffic lights on the route to the destination, curve information, traffic jam information, and the number of right / left turns has been proposed (see, for example, Patent Document 3). According to the navigation device described in Patent Literature 3, it is possible to select a route with less fatigue based on the degree of traffic congestion and the number of right / left turns that easily affect the driver's fatigue.
Japanese Patent Laid-Open No. 5-67263 Japanese Patent No. 3512493 JP 2006-17678 A

  However, the driving mental state detection device described in Patent Document 2 has a problem of increasing the cost and the vehicle weight because it is necessary to detect a heartbeat or the like in order to measure the driver's fatigue level. In addition, since the driving mental state detection device described in Patent Document 2 does not consider the relationship with the continuous driving time, it rests in a time extremely shorter or longer than the predetermined time (about 2 to 4 hours). May be advised to take.

  In addition, the navigation device described in Patent Document 3 detects fatigue from the number of traffic lights, curve information, traffic jam information, and the number of left / right turns, but other factors that greatly affect the driver's fatigue are not considered. There's a problem.

  In view of the above problems, the present invention can more accurately determine whether or not a driver is fatigued by suppressing an increase in cost, and can estimate the driver's fatigue more accurately. It is an object of the present invention to provide a device and a method for estimating driver fatigue.

  In view of the above problems, the present invention stores a fatigue map in which a high fatigue area is registered for each region in a driver fatigue level estimation device that performs measures to reduce driver fatigue when continuous operation time exceeds allowable drive time. Fatigue map storage means, fatigue level calculation means for calculating the fatigue level according to the high fatigue operating time of driving in a high fatigue area determined with reference to the fatigue map, and according to the fatigue level calculated by the fatigue level calculation means The reference change means for changing the allowable operation time, and the determination means for determining that it is time to perform the driver's fatigue reduction measure when the continuous operation time exceeds the allowable operation time.

  According to the present invention, the fatigue level is calculated according to the traveled area, and the allowable operation time compared with the continuous operation time is changed according to the fatigue level. It becomes possible to judge accurately.

  In one embodiment of the present invention, the first traveling road that detects that the driver has traveled on a road that is not used to driving by referring to the traveled road information that is registered for each road as to whether the driver is used to driving. Having a determination means, and when the first traveling road determination means detects that the vehicle has traveled on a road that is not familiar with driving, the fatigue level calculation means records the time during which the road was driven as the high fatigue driving time, It is characterized by.

  According to the present invention, since the road that passes for the first time is counted as the high fatigue driving time, the driver's fatigue level can be detected more accurately.

  A driver fatigue level estimation device and a driver fatigue level estimation method capable of more accurately determining whether or not a driver is tired by suppressing an increase in cost, and more accurately detecting driver fatigue. Can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

[Fatigue concept]
First, the concept of fatigue in the driver fatigue level estimation apparatus 100 of the present embodiment will be described. FIG. 1A is an example of a diagram schematically showing the relationship between driver fatigue and continuous driving time. If the magnitude of the driver's fatigue is referred to as the fatigue level, the driver's fatigue level is generally defined by the continuous operation time, and the continuous operation time is a predetermined time (for example, 2 hours, hereinafter referred to as the allowable operation time). Then, it is judged that the permissible fatigue level was reached and rest was necessary. When the allowable fatigue level is set uniformly as described above, the driver's fatigue level increases in proportion to the driving time as shown in the figure.

  However, it is considered that the driver's fatigue level is greatly influenced by the traveling condition of traveling. FIG.1 (b) shows an example of the driving | running | working condition which a driver | operator's fatigue degree tends to increase largely. For example, on a congested road, it is necessary to repeat the accelerator operation and the brake operation according to the distance from the preceding vehicle.On a three-dimensional road, there are frequent judgments of lanes, lane changes, interruptions of other vehicles, etc. Repeated stop / start by traffic lights, waiting for traffic lights, waiting for pedestrians to cross, etc. occur frequently. For this reason, it is considered that the driver is likely to feel fatigue in the driving situation as shown in FIG.

  On the other hand, in a countryside or a mountainous area (with few curves), the driver is less likely to feel fatigue, and the driver's fatigue may increase in proportion to time.

  Therefore, there is an area where there is a mixture of driving situations where the degree of fatigue such as traffic jams is likely to increase (hereinafter referred to as high fatigue zones) and driving situations where the degree of fatigue such as rural areas is difficult to increase (hereinafter referred to as low fatigue zones). When traveling, as shown in FIG. 1 (a), the fatigue level greatly increases (inclination increases) in the high fatigue zone, and the driver's fatigue level exceeds the allowable fatigue level before the allowable driving time is reached. (Hereinafter, the time when the driver's fatigue level exceeds the allowable fatigue level is referred to as the allowable fatigue level arrival time).

  The driver fatigue level estimation device 100 according to the present embodiment performs a driver fatigue reduction measure when the driver fatigue level exceeds the allowable fatigue level.

  Specifically, as described later, if the ease of increasing the fatigue level in the high fatigue zone is the same, the decrease in continuous operation time (allowable operating time-allowable fatigue level arrival time) It may be determined according to the travel time.

  Therefore, the driver fatigue level estimation device 100 calculates the ratio of the travel time of the high fatigue zone in the total travel time, and calculates the allowable fatigue level arrival time according to this ratio. Therefore, the apparent allowable operation time is reduced according to the ratio of the travel time of the high fatigue zone in the total travel time.

  Fatigue mitigation measures include, for example, giving advice to take a rest, drifting the scent of fragrance in the car, playing classical music, and guiding the route to the parking area. Various measures to reduce fatigue. The fatigue reduction measures may not be common to each driver, and each driver can set a desired fatigue reduction measure. In the following, we will give an example of advice to take a rest.

[Effects of first road on driver fatigue]
By the way, in addition to the above-mentioned congested roads, three-dimensional roads, and urban areas, the road on which the driver travels for the first time (hereinafter referred to as the first travel road) also causes the driver to feel great fatigue. This is probably because the driver cannot predict the previous situation, so a vehicle operation such as a sudden steering or a lane change is necessary or due to mental pressure. The driver fatigue level estimation device 100 according to the present embodiment detects the initial travel road and treats it in the same manner as the high fatigue zone, thereby enabling the driver fatigue level to be detected more accurately.

  FIG. 2 shows an example of a block diagram of the driver fatigue level estimation device 100. The driver fatigue level estimation device 100 is controlled by a predetermined ECU (Electronic Control Unit). In FIG. 2, the navigation ECU 20 controls the driver fatigue level estimation device 100 in consideration of the affinity with the navigation device. It was. Any ECU that is mounted on the vehicle may control the driver fatigue level estimation device 100.

  The navigation ECU 20 includes a GPS (Global Positioning System) receiver 11, a VICS (Vehicle Information and Communication System) receiver 12, a map DB (Data Base) 13, via an in-vehicle LAN such as a CAN (Controller Area Network) or a dedicated line. A display 14 and a speaker 15 are connected.

  The GPS receiver 11 determines the position (latitude / longitude / altitude) of the vehicle based on the arrival times of radio waves from a plurality of GPS satellites. Although not shown, the navigation ECU 20 receives vehicle speed information from the vehicle speed sensor and traveling direction information from the gyro sensor, and uses the position detected by the GPS receiver 11 as a reference in the traveling direction detected by the gyro sensor. By accumulating the travel distance included in the vehicle speed information, the position of the vehicle is estimated with high accuracy. The vehicle speed sensor measures, for example, a change in magnetic flux as a pulse when a convex portion provided at regular intervals passes on the circumference of a rotor provided in each wheel of the vehicle as a pulse. The wheel speed is measured for each wheel based on the number. The gyro sensor is a vibration piece type gyro sensor formed by, for example, micromachining, and the angular velocity when the vehicle rotates in the yawing direction or the pitching direction based on the distance of the vibration piece (between electrodes) that changes due to the action of the Coriolis force. Is detected.

  The VICS receiver 12 receives VICS information distributed by the VICS center. The VICS center distributes VICS information using three media: FM multiplex broadcasting, optical beacons, and radio beacons. The VICS receiver 12 receives VICS information by demodulating radio waves, radio beacons, and optical beacons multiplexed in FM broadcasting and returning them to baseband signals, and then performing signal processing to decode the original digital signals. The type of VICS information to be distributed and the area to be covered differ for each media, but the VICS information is, for example, traffic jam information, link travel time, traffic regulation information, parking, etc. associated with the VICS link classified by the VICS Center. Parking information, etc. In this embodiment, the congestion state of the road on which the vehicle has traveled is used as one factor for calculating the degree of fatigue, so traffic congestion information and link travel time related to congestion are extracted from the VICS information.

  The navigation ECU 20 may receive traffic information not only from the VICS but also from a probe car center (a server that generates and distributes traffic information from probe information collected from the probe car). The VICS information distributed by the VICS center is limited to those on major trunk roads, while the traffic information distributed by the probe car center can include all roads on which vehicles pass, so a wider range of traffic congestion information is received. it can.

  The map DB 13 is composed of a hard disk, a flash memory, etc., and stores road map information for forming a road network. The road map information is a table-like database that associates nodes corresponding to an actual road network with links connecting the nodes. The node table has node numbers, coordinates, the number of links flowing out from the nodes, and their link numbers. The link table has a link number, a start node and an end node constituting the link, a link length, and a direction with respect to the node. The node number and the link number are determined so as not to overlap each other, and a road network is formed by tracing the node number and the link number. The map DB 13 stores road types such as general roads and highways and facility information (point data) such as gas stations for each road.

  And high fatigue zone is memorize | stored in map DB13 of a present Example. FIG. 3A is a diagram schematically illustrating a road map showing a high fatigue zone. As shown in the figure, a road map is divided into meshes along latitude and longitude lines, and a high fatigue zone or a low fatigue zone is registered for each mesh (hereinafter referred to as a fatigue map). In the figure, the shaded area is a high fatigue zone. Therefore, by applying the position of the vehicle to the fatigue map, it can be determined whether the vehicle is traveling in a high fatigue zone or a low fatigue zone. In addition, the mesh-shaped divisions as shown in the figure can use the same divisions as the primary mesh to the tertiary mesh determined to handle the country divided into mesh shapes. The fatigue map may be stored in advance in the map DB 13 or may be downloaded from a predetermined server.

  By the way, laying objects such as three-dimensional roads are fixed on the fatigue map because they become a driving situation that increases the fatigue level all year round (always), but the congestion area is fixed to some extent, but it changes with time, The reason why urban areas are highly fatigued areas is that they are not considered to be highly fatigued areas at night because of the congestion in the daytime. Conversely, rural areas in low-fatigue zones may become high-fatigue zones due to the low number of lights laid at night, and similarly, mountainous areas are subject to rain and snow. Extremely difficult to drive and may be a high fatigue zone. In addition, there are areas that are always congested on weekends, and there are areas that are congested for leisure travelers in the summer and winter.

  Therefore, it is preferable that the fatigue map is not fixed and is used by switching according to the time zone, day of the week, season, weather, and the like. Note that the traffic jam area can be updated at any time using VICS information or the like, so it may not be stored in advance in the fatigue map, and may be reflected in the fatigue map every time traffic information is acquired.

  FIG. 3B shows an example of a fatigue map that is determined according to a time zone or the like. By referring to the fatigue map, the driver fatigue level estimation device 100 can flexibly determine whether the vehicle is in a high fatigue zone or a low fatigue zone according to the time zone, weather, or the like when the vehicle passes through the mesh.

  The fatigue map as shown in FIG. 3 (a) or (b) reads road shapes such as three-dimensional roads that can become high fatigue zones, regions such as mountainous areas from road map information for each mesh, time zone, day of the week, Depending on the season and weather, each mesh can be generated by determining whether it is a high fatigue zone or a low fatigue zone.

Examples of road shapes and areas that can become high fatigue zones are as follows.
・ Three-dimensional roads ・ Complex intersections (for example, four or more roads are connected)
・ Abrupt curves (eg, accident-prone areas, more than a predetermined radius of curvature)
-Continuous curves, mountainous areas, and coastal areas can all be read from the road map information stored in the map DB 13. Among these, meshes including solid roads, complicated intersections, sharp curves, and continuous curves are always registered in the fatigue map as high fatigue zones. A mesh including a mountainous area is registered in the fatigue map as a high fatigue zone during nighttime or snowing, and a mesh including a coastal area is registered in the fatigue map as a high fatigue zone during rainy weather.

  Returning to FIG. 2, the display 14 is a flat panel display such as a liquid crystal or an organic EL mounted with a touch panel, and is stored in, for example, a center cluster or a 2DIN storage unit. The speaker 15 is an audio output unit that outputs audio amplified by an amplifier. For example, the speaker 15 is disposed inside the door with the opening directed toward the passenger compartment. The display 14 and the speaker 15 serve as a user interface that notifies the driver that the allowable fatigue level has been reached. The display 14 has a touch panel, and serves as an input unit through which an occupant inputs an operation together with the periphery of the display 14, a remote controller, a voice input unit, and the like.

(Calculation of fatigue)
FIG. 4 shows an example of a functional block diagram of the navigation ECU 20. The navigation ECU 20 is a form of a computer including a CPU, an application specific integrated circuit (ASIC), an input / output interface, a register, a memory, a CAN interface, and the like. Then, the CPU executes a program stored in the memory, or is realized by hardware such as an ASIC, etc., and the continuous operation time measuring unit 21, the fatigue degree calculating unit 22, the determination criterion changing unit 23, and the advice determining unit 24 And a first traveling road determination unit 25.

  For example, when an IG (ignition) switch is turned on, the continuous operation time measurement unit 21 starts measuring continuous running time. Only when the vehicle speed is equal to or higher than a predetermined value, the driving time may be counted as the continuous driving time. Since it is “continuous” operation time, for example, when IG is turned off, the continuous operation time is initialized (becomes zero), and when IG is turned on next time, measurement of the continuous operation time is restarted from zero.

・ Detection of the first traveling road The first traveling road is, in principle, a road other than the road that has traveled in the past. Since the navigation ECU 20 associates the position of the own vehicle with a road (link) on the road map by map matching, the traveling road, that is, a road that has traveled is known.

  By the way, even if the road has traveled in the past, a road that has not traveled for a long time should be treated as the first travel road when judged from the point of familiarity with the driver. For this reason, in this embodiment, for each road, not only the presence / absence of travel, but also the travel date is recorded, and the road after a predetermined period from the travel date is regarded as the first travel road.

  FIG. 5 is a diagram illustrating an example of the traveled road information. The traveled road information is recorded in, for example, a link table of the map DB 13. The first travel road determination unit 25 records the travel date traveled in association with the link number of the traveled road.

  In the traveled road information, the number of times of traveling on the road in the past is registered. The initial travel road determination unit 25 increases the number of times one by one every time the same road is traveled, and decreases by one when, for example, several months have elapsed from the last travel date. By such calculation, the number of times correlated with the degree of learning of the driver can be recorded. In addition, roads that are not registered in the road information that has been traveled are roads that have never traveled or that have been traveled for more than a few months, that is, roads that are not used to driving. Become.

  It should be noted that a road that has traveled a large number of times may have been learned by the driver sufficiently, so a road that has traveled more than a predetermined number of times (for example, 20 times) has passed several months from the last travel date. May also be determined not to be deleted from the traveled road information. As a result, for example, roads that run very frequently, such as roads around homes or offices, are determined to be the first road even if several months have passed since the last day of travel due to a long business trip. Can be prevented.

  While the vehicle is traveling, the first travel road determination unit 25 refers to the traveled road information for each road and notifies the fatigue calculation unit 22 of the determination result as to whether or not the vehicle is the first travel road.

  In the present embodiment, it is determined whether or not the vehicle has traveled for each road. However, a mesh including a road that has never traveled may be registered in the fatigue map as a high fatigue zone. If you have traveled on some roads of the mesh, whether or not to use the mesh as a high fatigue zone is, for example, higher than half of the roads that have never traveled out of the total number of roads in the mesh. A fatigue zone. By registering in the fatigue map in this way, the first traveling road can be handled in the same manner as the traveling situation.

  The fatigue degree calculation unit 22 calculates the fatigue degree from the ratio of the operation time of the high fatigue zone (hereinafter referred to as “high fatigue operation time”) in the total travel time. Therefore, the fatigue level calculation unit 22 refers to the fatigue map in light of the position of the vehicle during driving, and measures the high fatigue driving time when traveling in a high fatigue zone.

  Similarly, according to the notification of the initial travel road determination unit 25, the fatigue level calculation unit 22 measures the high fatigue operation time while driving the initial travel road. If the high-fatigue zone overlaps with the first road, it is only necessary to measure the high-fatigue driving time of either one, but considering that the fatigue level is likely to increase due to the overlap between the high-fatigue zone and the first road. Then, the driving time of the first driving road and the driving time of the high fatigue zone may be counted as the high fatigue driving time.

FIG. 6 is an example of a diagram for schematically explaining the calculation of the fatigue level. In FIG. 6, among the continuous operation time t, a seconds, b seconds, and c seconds are high fatigue operation times. The fatigue level in this case is defined by the following equation (this fatigue level does not exactly match the fatigue level of FIG. 1).
Fatigue level = (a + b + c) / t × 100 (1)
For example, when the continuous operation time t is 5400 seconds (90 minutes), a = 600 seconds, b = 300 seconds, and c = 100 seconds, the fatigue level is calculated as 18.5.

[Change of judgment criteria]
The criterion changing unit 23 variably changes the criterion (allowable operation time in FIG. 1) according to the degree of fatigue. As described in FIG. 1, the allowable operation time (for example, 2 hours) is the maximum time during which continuous operation is allowed. In the present embodiment, the allowable operation time is changed according to the degree of fatigue, with the allowable operation time as one aspect of the determination criterion. Since the allowable operation time is considered to be shortened according to the fatigue level, for example, the allowable fatigue level arrival time is shortened by a ratio according to the fatigue level.
Allowable fatigue level arrival time =
Allowable operation time x (1- fatigue level / 100) (2)
Therefore, when the fatigue level is 18.5 and the allowable operation time is 120 minutes (2 hours), the allowable fatigue level arrival time is 97.8 minutes. By calculating the allowable fatigue level arrival time, an allowable driving time can be determined according to the fatigue level, and it can be determined whether or not the driver is tired.

  In addition, since Formula (2) is an example, for example, the degree of fatigue may be reduced (about 1/2 to 1/3) to reduce the effect of the degree of fatigue on the allowable fatigue time, The influence of the fatigue level on the allowable fatigue level arrival time may be increased by increasing the fatigue level (about 1.1 to 2 times).

[Determination of fatigue]
The advice determination unit 24 compares the allowable operation time changed by the determination criterion change unit 23 with the continuous operation time, and if the continuous operation time ≧ the allowable operation time (determination criterion), fatigue that the driver should take a rest It is determined that has accumulated. Accordingly, a message such as “Let's take a rest” can be output from at least one of the display 14 and the speaker 15 to advise the driver.

  Note that the advice determination unit 24 sets a minimum advice value for the continuous operation time for which advice is given. This is because, if the vehicle travels only in the high fatigue zone from the beginning of the operation, the allowable fatigue level arrival time becomes zero, and the continuous operation time becomes extremely short. Therefore, for example, a minimum advice value (for example, 60 minutes to 90 minutes) is set for the continuous operation time, and the allowable operation changed by the determination criterion changing unit 23 only when the continuous operation time exceeds the minimum advice value. Compare time (judgment criteria) and continuous operation time. Therefore, no advice is issued below this advice minimum.

[Operation procedure]
FIG. 7 is an example of a flowchart illustrating a procedure in which the driver fatigue level estimation device 100 advises to take a rest according to the driver's fatigue level. The flowchart of FIG. 7 starts when the ignition is turned on, for example.

  When the ignition is turned on, the continuous operation time measuring unit 21 starts measuring the continuous operation time (S10). Further, the fatigue level calculation unit 22 measures the high fatigue operation time when traveling on either the high fatigue zone or the first traveling road, and calculates fatigue according to the equation (1) from the high fatigue operation time and the continuous operation time. The degree is calculated (S20). Then, the determination criterion changing unit 23 changes the allowable operation time (determination criterion) according to the degree of fatigue using Expression (2) (S30).

  Next, the advice determination unit 24 determines whether or not the continuous operation time is greater than or equal to the determination criterion (S40). If the continuous driving time is less than the criterion (No in S40), the driver's fatigue level may not have reached the allowable fatigue level, and the processing from step S10 is repeated.

  If the continuous operation time is equal to or greater than the determination criterion (Yes in S40), it is determined that the driver's fatigue level has reached the allowable fatigue level, and the advice determination unit 24 operates from at least one of the display 14 or the speaker 15 The person is advised to rest (S50).

  If advised, the advice determination unit 24 requests the continuous operation time measurement unit 21 to reset (return to zero) the continuous operation time (S60). With this reset, the continuous operation time is measured again from zero.

  As described above, the driver fatigue level estimation apparatus 100 according to the present embodiment can vary the determination criteria as to whether or not the vehicle is fatigued according to the traveled area, and therefore travel that affects the fatigue level. Considering the situation, accurate fatigue determination can be performed. Further, since the fatigue level is calculated in consideration of the fact that the first driving road that is driven for the first time increases the fatigue level of the driver, it is possible to calculate the fatigue level more accurately.

  In the first embodiment, the criterion for determining whether or not the driver is tired is changed, but in this embodiment, the calculation method of the continuous operation time is changed without changing the criterion, so that the driving condition is changed. A driver fatigue level estimation apparatus 100 that performs accurate fatigue determination will be described. Note that the block diagram of the driver fatigue level estimation device 100 is the same as that in the first embodiment, and thus the description thereof is omitted.

  FIG. 8A is an example of a functional block of the navigation ECU 20, and FIG. 8B is an example of a diagram schematically illustrating calculation of weighted driving time according to the present embodiment. As shown in FIG. 8A, the navigation ECU 20 of the present embodiment does not have the determination criterion changing unit 23 and has a weighted operation time calculating unit 26 instead of the fatigue degree calculating unit 22.

[Calculation of weighted operation time]
The weighted driving time calculation unit 26 weights the driving time of traveling on the high fatigue zone and the first traveling road. For example, in FIG. 8B, a seconds, b seconds, and c seconds are high fatigue driving times in which the vehicle travels on the high fatigue zone and the first traveling road, but the weighted driving time calculation unit 26 calculates a seconds, b seconds. And c seconds.

  Specifically, for example, when traveling on a high fatigue zone and a first traveling road, the high fatigue operation time may be multiplied by K (high fatigue operation time × K). The weighting coefficient K is a value larger than 1, and can be set to a value between 1.1 and 4.0, for example.

Assuming that the total of a seconds, b seconds, and c seconds is 1000 seconds in the continuous operation time of 6200 seconds (about 103 minutes), the weighted operation time can be calculated as follows.
Weighted operation time = 5200 + 1000 × K
Here, if the weighting coefficient K = 2, the weighting operation time = 7200 seconds (120 minutes). Therefore, if the weighting coefficient K = 2, the continuous operation time exceeds 6200 seconds, the allowable operation time is exceeded. It can be advised to take a rest with a continuous running time similar to that of Example 1.

  As described above, when the weighted operation time calculation unit 26 of the present embodiment is traveling on the high fatigue zone or the first traveling road, the weighted operation time calculating unit 26 travels on the high fatigue region or the first traveling road by the high fatigue operation time × weighting coefficient K. High fatigue operating time.

In addition, since the continuous driving time includes the time when the high fatigue zone or the first driving road is driven, the low fatigue driving time is calculated by excluding the time when the high fatigue zone or the first driving road is driven from the continuous driving time. It is preferable. Thereby, calculation of weighted operation time becomes easy.
Weighted operation time = low fatigue operation time + high fatigue operation time × weighting coefficient K (3)
The weighting coefficient K can be variably set in the high fatigue area or the first driving road, and the weighting coefficient K can be variably set in a three-dimensional road or a congested road by subdividing the high fatigue area so that the driver can be more flexible. The weighted operation time can be calculated. Further, even if the road is not the first travel road (the road registered in the traveled road information), the weighting coefficient K can be set according to the elapsed time from the last travel date or the number of travels in the past. .

[Determination of fatigue]
And the advice determination part 24 of a present Example compares weighted driving time and allowable driving time, and when it becomes weighting driving time> = allowable driving time, the driver's fatigue level has reached the allowable fatigue level. judge.

  In the present embodiment, the continuous operation time that is directly permitted becomes shorter as the vehicle travels in a high fatigue area or the first driving road, so even if the calculated weighted operation time is provided to the driver as it is, for the driver. It is an easy-to-understand indicator.

[Operation procedure]
FIG. 9 is an example of a flowchart illustrating a procedure in which the driver fatigue level estimation device 100 advises to take a rest according to the weighted driving time of the driver. The flowchart in FIG. 9 starts when the ignition is turned on, for example.

  When the ignition is turned on, the continuous operation time measuring unit 21 starts measuring the continuous operation time (S10). The weighted operation time calculation unit 26 measures the high fatigue operation time when traveling on either the high fatigue zone or the first traveling road, and calculates the low fatigue operation time when traveling on the low fatigue zone. Each is measured (S21). Then, the weighted operation time calculation unit 26 calculates the weighted operation time from Expression (3) (S30).

  Next, the advice determination unit 24 determines whether or not the weighted operation time is equal to or greater than the allowable operation time (determination criterion) (S41). If the weighted driving time is less than the criterion (No in S41), the driver's fatigue level may not have reached the allowable fatigue level, and the process from step S10 is repeated.

  When the weighted driving time is equal to or more than the determination criterion (Yes in S41), it is determined that the driver's fatigue level has reached the allowable fatigue level, and the advice determination unit 24 operates from at least one of the display 14 or the speaker 15 to drive. The person is advised to rest (S50).

  When giving advice, the advice determination unit 24 requests that the continuous operation time be reset (returned to zero) (S60). With this reset, the continuous operation time is measured again from zero.

  As described above, in addition to the effects of the first embodiment, the driver fatigue level estimating apparatus 100 according to the present embodiment determines whether or not the driver is tired based on an index that is easy for the driver to understand. enable.

  In the first and second embodiments, the driver fatigue level estimation device 100 stores the fatigue map in advance, but in this example, while determining whether the road is likely to increase the fatigue level during traveling, The driver fatigue level estimation device 100 that calculates the fatigue level will be described. Note that the block diagram of the driver fatigue level estimation device 100 is the same as that in the first embodiment, and thus the description thereof is omitted.

  FIG. 10A is an example of a functional block of the navigation ECU 20, and FIG. 10B is an example of a diagram for schematically explaining the calculation of the fatigue level of the present embodiment. In FIG. 10A, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 10A, the navigation ECU 20 of the present embodiment does not have the determination reference change unit 23, and has a high fatigue road determination unit 27 instead of the initial travel road determination unit 25. The high fatigue road determination unit 27 refers to the map DB 13 based on the position information of the vehicle, and causes high fatigue roads that cause high fatigue for each road (link), such as a congested state, the presence or absence of a three-dimensional road, the presence or absence of a complicated intersection, It is determined whether or not there is a sharp curve, whether or not there is a continuous curve, and whether or not the road is the first road. The determination method and criteria are the same as those in the first embodiment. In this embodiment, since it is determined whether the vehicle is actually running and a high fatigue road, the steering angle sensor detects the presence or absence of a sharp curve, for example. It can be determined from the yaw rate or the like. Moreover, since it is determined whether it is high fatigue | exhaustion for every road instead of the fatigue map which determined whether it causes high fatigue over a wide range like a mesh, it becomes possible to detect a more exact fatigue degree.

  And the fatigue degree calculation part 22 calculates a fatigue degree from the ratio of the driving time of the high fatigue road in all the travel time similarly to Example 1. FIG. Therefore, according to the notification of the high fatigue road determination unit 27, the fatigue level calculation unit 22 measures the high fatigue driving time while driving on the high fatigue road. In FIG. 10B, among the continuous operation time t, a seconds, b seconds, and c seconds are high fatigue operation times. The formula for calculating the degree of fatigue is the same as formula (1).

  In addition, since it is determined whether or not each road is a high fatigue road, it is possible to weight the high fatigue driving time for each road as in the second embodiment. Therefore, not only can a more accurate degree of fatigue be detected, but also the weighting coefficient K can be changed for each road, and the weighted driving time can be calculated flexibly.

[Determination of fatigue]
Also in the advice determination unit 24 of the present embodiment, the fatigue level calculated from the formula (1) of the first embodiment is applied to the formula (2) to change the determination criterion, and the continuous operation time ≧ the allowable fatigue level reaching time ( In the case of (judgment criteria), it can be determined that the driver is fatigued to take a rest. Similarly to the second embodiment, the weighted driving time is calculated from the expression (3), and when the weighted driving time ≧ the allowable driving time (determination criterion), it is determined that the driver has fatigue to take a rest. Also good.

  Further, the advice determination unit 24 calculates the fatigue level from the equation (1), and compares the fatigue level with a predetermined determination threshold value. It may be determined that it has accumulated. Although the determination threshold value is “15” in the figure, this means that 15% or more of the total travel time occupies the drive time of the high fatigue road. For example, a continuous operation time of 6200 seconds (about 103 minutes) corresponds to 930 seconds. That is, even with such a determination method, it can be determined that the driver is fatigued to take a rest in the continuous operation time similar to that in the first or second embodiment.

  If it is determined that there is fatigue, the driver fatigue level estimation device 100 outputs a message such as “Let's take a rest” from at least one of the display 14 and the speaker 15 to advise the driver. Also in this embodiment, the advice determination unit 24 sets a minimum advice value for the continuous operation time to advise. Therefore, no advice is issued below this advice minimum.

[Operation procedure]
FIG. 11 is an example of a flowchart illustrating a procedure in which the driver fatigue level estimation device 100 advises to take a rest according to the driver's fatigue level. The flowchart of FIG. 11 starts when, for example, the ignition is turned on.

  When the ignition is turned on, the continuous operation time measuring unit 21 starts measuring the continuous operation time (S10). The fatigue degree calculation unit 22 measures the high fatigue operation time when traveling on a high fatigue road, and calculates the fatigue degree from the high fatigue operation time and the continuous operation time (S20).

  Next, the advice determination unit 24 determines whether the fatigue level is equal to or higher than a determination threshold (S42). If the fatigue level is less than the determination threshold (No in S42), the driver's fatigue level may not have reached the allowable fatigue level, and thus the processing from step S10 is repeated.

  When the fatigue level is equal to or higher than the criterion (Yes in S42), it is determined that the driver's fatigue level has reached the allowable fatigue level, and the advice determination unit 24 determines the driver from at least one of the display 14 or the speaker 15. Is advised to rest (S50).

  When giving advice, the advice determination unit 24 requests that the continuous operation time be reset (returned to zero) (S60). With this reset, the continuous operation time is measured again from zero.

  As described above, the driver fatigue level estimation apparatus 100 according to the present embodiment can detect a more accurate and flexible fatigue level by determining whether or not each road is a high fatigue road.

  In the driver fatigue level estimation apparatus 100 according to the first to third embodiments, the allowable fatigue level arrival time is shorter than the allowable driving time due to driving in a high fatigue zone or a high fatigue road. However, accumulation of fatigue due to driving in high fatigue zones or high fatigue roads is considered to be mitigated if comfortable driving continues (hereinafter, roads other than high fatigue zones or roads other than high fatigue roads are treated as low fatigue roads). Called). Comfortable traveling is, for example, a case where the vehicle is traveling on a zone or road where the steering operation is small or the frequency of accelerator and braking operations is sufficiently low, and such a traveling state corresponds to a low fatigue road. Also, forcing driving to take a rest while driving comfortably reduces drivability.

  Therefore, in this embodiment, even when driving in a high fatigue zone or a high fatigue road, if the low fatigue road continues for a predetermined time or more, the driver fatigue level estimation that can extend the allowable fatigue level arrival time to the allowable driving time The apparatus 100 will be described. Note that the block diagram of the driver fatigue level estimation device 100 is the same as that in the first embodiment, and thus the description thereof is omitted.

  FIG. 12A shows an example of a functional block diagram of the navigation ECU 20. FIG. 12B shows an example of a diagram that schematically explains the calculation of the fatigue level of the present embodiment. The calculation of the fatigue level will be described by taking Example 1 as an example. However, since the fatigue level is calculated by correcting the high fatigue operation time a to c seconds, the calculation can be similarly applied to the calculation of the weighted operation time of Example 2. In the present embodiment, it is determined whether or not each road is a high fatigue road. However, as in the first or second embodiment, it may be determined whether or not the road is a high fatigue zone with reference to the fatigue map.

(Calculation of fatigue)
The driver fatigue level estimation apparatus 100 according to the present embodiment calculates the previous high fatigue operation times a to c if the time during which the low fatigue road is continuously operated (hereinafter referred to as the low fatigue continuous operation time T) is sufficiently long. This is reduced by the fatigue relaxation time α following the low fatigue continuous operation time T. Specifically, the fatigue relaxation time α is multiplied by a constant P of 1 or less and subtracted from the high fatigue operation time a. The constant P is, for example, about 0.1 to 0.5.

  The low fatigue duration determination unit 28 determines whether or not the time for continuously driving on a low fatigue road has become longer than the low fatigue continuous operation time T. The degree calculation unit 22 is notified. The fatigue level calculation unit 22 receives the notification and calculates the fatigue level as follows. For example, if the time from passing through a high fatigue road with a high fatigue operation time a until reaching the high fatigue road with a high fatigue operation time b is longer than the low fatigue continuous operation time T, the high fatigue operation is performed. The time a is reduced to (a−P · α1). Assuming that the time from passing through the high fatigue road of the high fatigue operation time b to reaching the high fatigue road of the high fatigue operation time c is longer than the low fatigue continuous operation time T, the high fatigue operation time c Is reduced to (a−P · α2).

  On the other hand, if the time from passing through the high fatigue road of the high fatigue operation time b to reaching the high fatigue road of the high fatigue operation time c is equal to or less than the low fatigue continuous operation time T, the high fatigue operation time b is not corrected.

Therefore, the fatigue level is calculated by the following equation.
Fatigue degree = {(a−P · α1) + b + (c−P · α2)} / t × 100 (4)
For example, when P = 0.1, if the fatigue relaxation time α continues for 10 times the high fatigue operation time after the low fatigue continuous operation time T has elapsed, the high fatigue operation time becomes zero.

Thus, only when the driving on the low fatigue road continues longer than the low fatigue continuous operation time T, the high fatigue driving time a can be reduced and the calculated fatigue level can be reduced. According to the equation (4), if the fatigue relaxation time α following the low fatigue continuous operation time T is sufficiently long, the fatigue level can be made zero. Therefore, the allowable fatigue level arrival time calculated by the equation (2) is set as the allowable operation time. Can be equal. Moreover, such a way of thinking is in line with the way of thinking that the driver tends to accumulate fatigue as the high fatigue road continues.

[Operation procedure]
FIG. 13 is an example of a flowchart illustrating a procedure in which the driver fatigue level estimation device 100 advises to take a rest according to the driver's fatigue level. The flowchart in FIG. 13 starts when the ignition is turned on, for example.

  When the ignition is turned on, the continuous operation time measuring unit 21 starts measuring the continuous operation time (S10). Further, the low fatigue duration determination unit 28 determines whether or not the driving time for continuously driving on the low fatigue road exceeds the low fatigue duration driving time T (S15).

  The fatigue level calculation unit 22 measures the high fatigue operation time when traveling on a high fatigue road, corrects the high fatigue operation time according to the fatigue relaxation time α, and corrects the high fatigue operation time. The fatigue level is calculated from the continuous operation time (S20). Then, the criterion changing unit 23 changes the criterion according to the degree of fatigue (S30).

  Next, the advice determination unit 24 determines whether or not the continuous operation time is greater than or equal to the determination criterion (S40). If the continuous driving time is less than the criterion (No in S40), the driver's fatigue level may not have reached the allowable fatigue level, and the processing from step S10 is repeated.

  If the continuous operation time is equal to or greater than the determination criterion (Yes in S40), it is determined that the driver's fatigue level has reached the allowable fatigue level, and the advice determination unit 24 operates from at least one of the display 14 or the speaker 15 The person is advised to rest (S50).

  When giving advice, the advice determination unit 24 requests that the continuous operation time be reset (returned to zero) (S60). With this reset, the continuous operation time is measured again from zero.

  As described above, the driver fatigue level estimation device 100 according to the present embodiment can make the allowable fatigue level arrival time equal to the allowable driving time in addition to the effects of the first to third embodiments. You can advise them to rest at a time that takes fatigue into account.

It is an example of the figure which shows typically the relationship between a driver | operator's fatigue degree and continuous driving time. 1 is an example of a block diagram of a driver fatigue level estimation device 100. FIG. It is an example of the figure which illustrates the road map which shows a high fatigue zone typically. It is an example of the functional block diagram of navigation ECU (Example 1). It is a figure which shows an example of road information after driving | running | working. It is an example of the figure which illustrates calculation of fatigue degree typically. (Example 1) which is an example of the flowchart figure which shows the procedure which a driver | operator fatigue degree estimation apparatus advises to take a rest according to a driver | operator's fatigue degree. It is an example of the figure which illustrates an example of the functional block of navigation ECU, and calculation of weighted driving | running time typically (Example 2). (Example 2) which is an example of the flowchart figure which shows the procedure which a driver | operator fatigue degree estimation apparatus advises to take a rest according to a driver | operator's weighted driving time. It is an example of the figure which illustrates an example of the functional block of navigation ECU, and the calculation of a fatigue degree typically (Example 3). (Example 3) which is an example of the flowchart figure which shows the procedure which a driver | operator fatigue degree estimation apparatus advises to take a rest according to a driver | operator's fatigue degree. It is an example of the figure which illustrates an example of the functional block of navigation ECU, and the calculation of a fatigue degree typically (Example 4). (Example 4) which is an example of the flowchart figure which shows the procedure which a driver | operator fatigue degree estimation apparatus advises to take a rest according to a driver | operator's fatigue degree.

Explanation of symbols

13 Map DB
14 Display 15 Speaker 20 Navi ECU
DESCRIPTION OF SYMBOLS 21 Continuous driving | running time measurement part 22 Fatigue degree calculation part 23 Judgment criteria change part 24 Advice determination part 25 First run road determination part 26 Weighted driving time calculation part 27 High fatigue road determination part 28 Low fatigue duration determination part 100 Driver fatigue degree Estimator

Claims (9)

When the continuous driving time exceeds the allowable driving time, in the driver fatigue level estimation device that performs the driver's fatigue reduction measures,
A fatigue map storage means for storing a fatigue map in which a high fatigue area is registered for each area;
Fatigue degree calculating means for calculating the fatigue degree according to the high fatigue operation time of driving the high fatigue area determined with reference to the fatigue map,
In accordance with the degree of fatigue calculated by the fatigue level calculating means, reference changing means for changing the allowable operating time;
A determination unit that determines that it is time to perform the fatigue reduction measure of the driver when a continuous operation time exceeds the allowable operation time;
A driver fatigue level estimation device characterized by comprising: It has first running road determination means for detecting that the driver has traveled on a road that is not used to driving, referring to the road information that has been registered for each road as to whether the driver is familiar with driving or not,
When it is detected that the first travel road determination means travels on a road that is not familiar with driving, the fatigue level calculation means records the time when the road was driven in the high fatigue driving time,
The driver fatigue level estimation apparatus according to claim 1, wherein In the fatigue map, whether or not the area is a high fatigue area is registered according to at least one of time zone, day of the week, season or weather,
3. The driver fatigue level estimation apparatus according to claim 1 or 2, The fatigue level calculating means calculates the fatigue level from a ratio of the high fatigue operating time to continuous operating time.
The driver fatigue level estimation device according to any one of claims 1 to 3, wherein Weighted operation time calculation means for weighting the high fatigue operation time, adding the high fatigue operation time weighted to continuous operation time, and calculating weighted operation time,
When the weighted driving time exceeds the allowable driving time, the determining means determines that it is time to perform the driver's fatigue reduction measures.
The driver fatigue level estimation apparatus according to claim 1, wherein When the fatigue level calculated by the fatigue level calculation unit exceeds a predetermined determination threshold, the determination unit determines that it is time to perform the driver's fatigue reduction measures.
The driver fatigue level estimation apparatus according to claim 1, wherein It has a low fatigue duration determination means for determining whether it is continuously driving for a predetermined time or more in an area other than the high fatigue area or a road familiar to driving,
The fatigue level calculating means reduces the high fatigue driving time according to the driving time of driving continuously on a road other than the high fatigue area or a road accustomed to driving,
3. The driver fatigue level estimating apparatus according to claim 2, wherein If the determination means determines that it is time to perform the driver's fatigue reduction measures,
Advisory means to advise the driver to take a rest,
The driver fatigue level estimation device according to any one of claims 1 to 7, characterized by comprising: When the continuous driving time exceeds the allowable driving time, in the driver fatigue level estimation method for reducing the driver's fatigue,
The step of calculating the degree of fatigue according to the high fatigue operation time in which the fatigue level calculation means has been operated with reference to the fatigue map storage means for storing the fatigue map in which the high fatigue area is registered for each area. When,
A step of changing the allowable operation time in accordance with the fatigue level calculated by the fatigue level calculating unit;
A step of determining that when the continuous operation time exceeds the allowable operation time, the determination means is a timing for performing the fatigue reduction measure of the driver;
A driver fatigue level estimation method comprising:

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