JP5114342B2 - Arousal level judgment device - Google Patents

Description

  The present invention relates to an arousal level determination device that determines arousal level of a driver of an automobile and the like, and more particularly to a device that learns a determination value used for determination of arousal level.

  The arousal level determination device determines the level of arousal of a subject such as a driver of an automobile, for example. The wakefulness determination device is used, for example, to issue a warning to the driver when the wakefulness is lowered, or to change the control state of the driving support device that supports the driving operation of the driver.

For example, Patent Literature 1 describes a wakefulness detection device that detects the state of driving operation and the health state of a driver and detects the wakefulness level by fuzzy inference.
Further, Patent Document 2 describes that the control state of the lane tracking support device is changed according to the estimation result by the arousal level estimation means.

In addition, in Patent Document 3, when the degree of decrease in driving intention is equal to or greater than a predetermined threshold over a predetermined determination time, steering assist processing is prohibited, notification by notification means, and travel speed, curve curvature, etc. It describes that the determination time is determined according to road conditions.
JP-A-5-54300 JP 2007-261451 A JP 2007-168720 A

In the arousal level determination device, in order to realize the determination of a reduction in arousal level adapted to individual differences among drivers, it is desirable to correct the learning value used for determination according to the driving operation of the driver.
However, the relationship between the decrease in the driver's arousal level and the decrease in the amount of driving operation varies depending on the driving environment and the driver's state. For example, in the case of a road that travels less frequently, such as a road that travels for the first time, there is a case where the correlation between a decrease in arousal level and a decrease in the amount of driving operation may differ from usual because the burden of route confirmation and safety confirmation is high. . Further, immediately after the start of driving, even if the arousal level is high, the driving operation of the driver is likely to vary. In such a case, learning of the determination value of the arousal level determination may cause erroneous learning, and an appropriate arousal level determination may not be performed.
The subject of this invention is providing the arousal level determination apparatus which learns the determination value of arousal level determination appropriately.

The present invention solves the above-described problems by the following means.
The invention of claim 1 is a wakefulness determination device for determining the wakefulness of a driver driving a vehicle, the steering state detecting means for detecting a steering operation amount or a steering force of the driver, and the steering operation amount or the steering. Counter means for counting the elapsed time in a state where the force is less than or equal to a predetermined value, a wakefulness reduction determining means for determining a decrease in the driver's wakefulness when the elapsed time is equal to or greater than a determination value, and the driving state of the driver Based on determination value learning means for performing learning correction of the determination value based on the above, a determination is made as to whether or not the vehicle has traveled on the road on which the vehicle is traveling in the past, and the number of travels is detected. And the determination value learning means permits learning correction of the determination value based on the driving state when the number of times of travel is equal to or greater than a predetermined number of times, and the number of times of travel is less than the predetermined number of times Is awareness determination apparatus characterized by prohibiting the learning correction of the determination value to a certain time.
The invention of claim 2 is characterized in that the judgment value learning means permits learning correction of the judgment value only when the elapsed time from the start of operation of the driver is equal to or greater than a predetermined lower limit value. 1. The arousal level determination device according to 1.

  According to a third aspect of the present invention, there is provided a wakefulness determination device for determining the wakefulness of a driver driving a vehicle, the steering state detecting means for detecting a steering operation amount or a steering force of the driver, and the steering operation amount or the steering. Counter means for counting the elapsed time in a state where the force is less than or equal to a predetermined value, a wakefulness reduction determining means for determining a decrease in the driver's wakefulness when the elapsed time is equal to or greater than a determination value, and the driving state of the driver Determination value learning means for performing learning correction of the determination value based on the determination value learning means, wherein the determination value learning means is based on the driving state when an elapsed time from the start of operation of the driver is equal to or greater than a predetermined lower limit value. An arousal level determination device that permits learning correction of a determination value and prohibits learning correction of the determination value when the elapsed time is less than the lower limit value.

The invention of claim 4 is characterized in that the judgment value learning means permits learning correction of the judgment value only when the elapsed time from the start of operation of the driver is less than a predetermined upper limit value. It is a wakefulness determination apparatus of Claim 2 or Claim 3.
According to a fifth aspect of the present invention, the determination value is corrected by learning based on an elapsed time in which the steering operation amount or the steering force is equal to or less than a predetermined value in a state where learning correction of the determination value is permitted. The wakefulness determination device according to any one of claims 1 to 4, wherein the wakefulness determination device is provided.
The invention of claim 6 comprises travel environment recognition means for recognizing the travel environment of the host vehicle, and determination value switching means for switching a plurality of the determination values according to the travel environment, wherein the determination value learning means 6. The correction according to claim 1, wherein when the learning correction of the determination value is permitted, the determination value corresponding to the currently traveling environment is learned and corrected. It is a wakefulness determination device.

According to the present invention, the following effects can be obtained.
(1) The determination value learning means permits learning correction of the determination value based on the driving state of the driver and the number of times of traveling is predetermined when the number of times of traveling from the past of the road on which the vehicle is traveling is equal to or greater than a predetermined value. By prohibiting the learning correction of the judgment value when the number is less than the number of times, it is possible to prevent inappropriate learning correction from being performed by the steering operation when driving on an unfamiliar road, and appropriate learning correction and arousal level Judgment can be made.
(2) The judgment value learning means permits the learning correction of the judgment value only when the elapsed time from the start of driving of the driver is equal to or greater than a predetermined lower limit value. It is possible to prevent inappropriate learning correction from being performed at the beginning of driving that is likely to occur, and to perform appropriate learning correction and arousal level determination.
(3) The determination value learning means permits the correction of the determination value only when the elapsed time from the start of driving of the driver is less than a predetermined upper limit value, thereby easily affecting the driver's fatigue or the like. It is possible to prevent inappropriate learning correction from being performed based on the driving operation during driving, and to perform appropriate learning correction and arousal level determination.
(4) The determination value is set according to the driving environment. When the arousal level is determined, the determination value corresponding to the driving environment at that time is used. Therefore, when the learning correction of the determination value is permitted, the determination value learning means performs the learning correction of the determination value corresponding to the driving environment at that time, thereby determining the arousal level using an appropriate determination value in each driving environment. It can be performed.

  The present invention provides a problem of providing a wakefulness determination device that appropriately learns a determination value of wakefulness determination, and is determined after a predetermined time has elapsed since the start of driving while driving on a road whose past driving count is equal to or greater than a predetermined value. It was solved by performing learning correction of values.

Hereinafter, embodiments of an arousal level determination apparatus to which the present invention is applied will be described.
FIG. 1 is a diagram illustrating a system configuration of a vehicle having an arousal level determination device according to an embodiment.
The wakefulness determination device according to the embodiment is provided in an automobile such as a passenger car, for example, and determines the driver's wakefulness based on the steering operation history.

  The vehicle includes a steering mechanism 10, an electric power steering (EPS) control unit 20, a steering control unit 30, an engine control unit 40, a transmission control unit 50, a navigation device 60, a vehicle integration unit 70, and the like.

The steering mechanism 10 performs steering by rotating the housing H that supports the front wheel FW about a predetermined steering axis (king pin).
The steering mechanism 10 includes a steering wheel 11, a steering shaft 12, a steering gear box 13, a tie rod 14, and the like.
The steering wheel 11 is an annular operation member through which a driver inputs a steering operation.
The steering shaft 12 is a rotating shaft that transmits the rotation of the steering wheel 11 to the steering gear box 13.
The steering gear box 13 includes a rack and pinion mechanism that converts the rotational movement of the steering shaft 12 into a straight movement in the vehicle width direction.
The tie rod 14 is a shaft-like member having one end connected to the rack of the steering gear box 13 and the other end connected to the knuckle arm of the housing H. The tie rod 14 steers by rotating the housing H by pushing and pulling the knuckle arm of the housing H.

The EPS control unit 20 comprehensively controls an electric power steering device that generates a steering assist force in accordance with a driver's steering operation. The EPS control unit 20 is connected to an electric actuator 21, a torque sensor 22, and the like.
The electric actuator 21 is, for example, an electric motor that is provided in the middle of the steering shaft 12 and applies a steering torque (steering force) to the steering mechanism 10 via a speed reduction mechanism.
The torque sensor 22 is inserted into the steering shaft 12 between the electric actuator 21 and the steering wheel 11 and detects torque acting on the steering shaft 12. Normally, the torque detected by the torque sensor 22 is substantially equal to the steering torque input to the steering wheel 11 by the driver, that is, the steering force.

The steering control unit 30 performs vehicle steering control and ABS control for individually controlling the braking force of each wheel brake. In vehicle stability control, when understeer or oversteer occurs, the braking force on the turning inner wheel side and the outer wheel side is made different to generate a yaw moment in the restoring direction. ABS control (anti-lock brake control) is for reducing and recovering the braking force of a wheel when the tendency of the wheel to lock is detected.
The steering control unit 30 is connected to a hydraulic control unit (HCU) 31, a vehicle speed sensor 32, a yaw rate sensor 33, a lateral acceleration (lateral G) sensor 34, a steering angle sensor 35, and the like.

The HCU 31 is a device that individually controls the brake fluid pressure applied to the hydraulic service brake of each wheel. The HCU 31 includes a motor pump that pressurizes the brake fluid, a solenoid valve that adjusts the pressure applied to the caliper cylinder of each wheel, and the like.
The vehicle speed sensor 32 is provided in a housing that holds the hub bearing of each wheel, and outputs a vehicle speed pulse signal corresponding to the wheel speed. The vehicle speed pulse signal is subjected to predetermined processing, whereby the traveling speed of the vehicle can be obtained.
The yaw rate sensor 33 and the lateral G sensor 34 include a MEMS sensor that detects a rotational speed around the vertical axis of the vehicle body and a lateral acceleration, respectively.
The steering angle sensor 35 includes an encoder that detects the angular position of the steering shaft 12 (substantially equal to the angular position of the staying wheel 11).

The engine control unit 40 controls the engine, which is a driving power source for the vehicle, and its auxiliary equipment. The engine control unit 40 is connected to an ignition switch (not shown) for starting the engine.
The transmission control unit 50 controls the automatic transmission that shifts the output of the engine and transmits it to the front and rear differentials.
The navigation device 60 includes a storage device such as an HDD that stores map data and a positioning device such as a GPS receiver, and has a function of determining the road on which the vehicle is currently traveling.
The vehicle integration unit 70 controls the electrical components of the vehicle other than those related to each unit.

The vehicle also includes a steering assist device 100, a wakefulness determination device 200, an alarm determination unit 310, an alarm device 320, and the like described below.
The steering assist device 100 and the arousal level determination device 200 include the EPS control unit 20, the operation control unit 30, the engine control unit 40, the transmission control unit 50, the navigation device 60, the vehicle integration unit 70, and the like described above, for example, a CAN communication system. It is possible to acquire various kinds of information and signals through an in-vehicle LAN.

  The steering assist device 100 includes an environment recognition unit 110, a target travel position setting unit 120, a host vehicle traveling path estimation unit 130, a steering force control unit 140, and the like. Each of these elements may be configured as independent hardware, or part or all may be configured as common hardware.

The environment recognition unit 110 recognizes the shape of the traveling lane of the host vehicle based on image information obtained by capturing the front of the host vehicle.
The environment recognition unit 110 is connected to a stereo camera 111, an image processing unit 112, and the like.
The stereo camera 111 includes, for example, a pair of main cameras and sub-cameras provided near the room mirror base at the upper end of the front window of the vehicle. Each of the main camera and the sub camera has a CCD camera. The main camera and the sub camera are installed apart from each other in the vehicle width direction. The main camera and the sub camera capture a reference image and a comparative image, respectively, and output image data related to these images to the image processing unit 112.
The image processing unit 112 performs A / D conversion on the image data of the reference image and the comparison image output from the stereo camera 111, performs predetermined image processing, and outputs the result to the environment recognition unit 110. This image processing includes, for example, correction of an attachment position error of each camera, noise removal, gradation optimization, and the like. The digitized image has, for example, a plurality of pixels arranged in a matrix in the vertical direction and the horizontal direction. Each of these pixels has a luminance value corresponding to the brightness of the subject.

  The environment recognition unit 110 detects parallax of a pixel group that is a block composed of an arbitrary pixel or a plurality of pixels on the reference image based on the data of the reference image and the comparison image. This parallax is the amount of deviation between the position on the reference image and the position on the comparison image of a certain pixel or pixel group. Using this parallax, the distance from the vehicle to the subject corresponding to the pixel can be calculated based on the principle of triangulation.

Further, the environment recognition unit 110 recognizes the shape of white lines arranged at both ends of the lane ahead of the host vehicle. In this specification, claims, etc., a white line means a continuous line or a broken line drawn at the end in the width direction of the lane, and the actual color is other than white (for example, amber) Includes lines.
The environment recognition unit 110 detects a pixel group in the white line portion based on the luminance data of the pixel from the reference image data. The orientation of the pixel group of the white line portion with respect to the host vehicle is detected based on the pixel position on the image data. Specifically, an area corresponding to a pixel position in the vertical direction on the road surface is scanned in the horizontal direction, and a portion where the luminance value changes suddenly is recognized as a lane outline. Then, the position of the white line is detected by calculating the distance of the pixel group in the white line portion.
The environment recognition unit 110 can continuously detect the position of the white line to set a plurality of lane candidate points in the traveling direction of the vehicle, ignore the lane candidate points that cannot be matched, and set the lane candidate points. The area that does not exist is subjected to a predetermined complement process to recognize the lane shape ahead of the host vehicle.

  The target travel position setting unit 120 sets the target travel position Xc at the center in the width direction of the travel lane of the host vehicle set by the environment recognition unit 110.

The own vehicle traveling path estimating unit 130 is based on information from the environment recognizing unit 110, the vehicle running state detected by the vehicle speed sensor 32, the yaw rate sensor 33, the rudder angle sensor 35, etc., and known vehicle specifications. The vehicle traveling path is estimated. The own vehicle traveling path estimation unit 130 functions as the own vehicle lateral position recognition means according to the present invention.
The own vehicle traveling path is estimated by, for example, calculating the lateral position Xe of the own vehicle at the gaze distance Z in front of the vehicle.
The following description will be made using a coordinate system having the center of gravity of the host vehicle as the origin, the X axis extending in the vehicle width direction, and the Z axis extending forward of the vehicle body.
The estimated lateral position Xe of the host vehicle's center of gravity at the gaze distance Z is obtained by the following equation 1 using the handle angle α.

In addition, the host vehicle traveling path estimation unit 130 may estimate the lateral position using the yaw rate detected by the yaw rate sensor 33 as shown in the following equation 2, instead of estimating the lateral position using the steering wheel angle. it can.

Xe = Z ² γ / 2V (Formula 2)
Xe: Estimated lateral position of the center of gravity of the vehicle at the gaze distance Z [m]
Z: Gaze distance [m]
γ: vehicle yaw rate [rad / s]

The steering force control unit 140 sets a target steering torque τ to be applied to the steering mechanism 10 using the target travel position setting unit 120 and the own vehicle traveling path estimation unit 130.
The target steering torque τ is set, for example, by multiplying a cube value of the lateral deviation of the estimated lateral position Xe of the host vehicle with respect to the target travel position Xc by a predetermined gain and performing necessary correction.
The steering force control unit 140 transmits an instruction value corresponding to the target steering torque τ to the EPS control unit 20 to drive the electric actuator 21.

The arousal level determination device 200 includes a travel path detection unit 210, a history accumulation unit 220, a travel mode determination unit 230, a driving operation detection unit 240, a wakefulness level decrease determination unit 250, a wakefulness level decrease learning unit 260, and the like. Yes.
The travel path detection unit 210 acquires information about the road on which the host vehicle is currently traveling from the navigation device 60 and transmits the information to the history storage unit 220.
The history accumulating unit 220 accumulates a history of roads on which the host vehicle has traveled during a predetermined period in the past. In response to an inquiry from the awakening level decrease learning unit 260 or the like, the history accumulation unit 220 searches for a travel history of the road on which the host vehicle is currently traveling (the number of travels indicating how many times the vehicle has traveled in a certain past period). It has a function.

The travel mode determination unit 230 determines whether the road on which the host vehicle is currently traveling is a general road or a highway, and further determines whether the road is a curved road or a straight line if the road is a general road. . This determination will be described in detail later.
The driving operation detection unit 240 acquires the output value of the steering angle sensor 35 via the steering control unit 30 and detects the steering wheel angle (the angle of the steering wheel 11).

The arousal level reduction determination unit 250 determines a reduction in the driver's arousal level based on the steering wheel angle detected by the driving operation detection unit 240. The wakefulness reduction determination unit 250 determines whether the change in the steering wheel angle, that is, the duration of the state in which the driver's steering operation amount is equal to or less than a predetermined threshold (a state in which there is substantially no steering operation) (the count value of the timer) is a predetermined determination. When the value exceeds the value, a decrease in arousal level is determined. The arousal level decrease determination unit 250 includes timer means for counting the duration time. The determination value is a value obtained by adding a predetermined value to a counter learning value described later.
The awakening level decrease determination unit 250 has determination values for each of a straight road, an expressway, and a curved road, and selects a corresponding determination value according to the travel mode determined by the travel mode determination unit 230. In addition, when the driving mode transitions and switches to a different determination value, the arousal level decrease determination unit 250 performs a predetermined correction on the counter value in the previous mode and takes over (sets the counter value in the new mode). It has a function. This point will be described in detail later.

The awakening level decrease learning unit 260 performs learning correction of the counter learning value used in the awakening level decrease determination unit 250 based on the driving state of the driver in order to reflect the individual difference of the driver for each driving environment in the awakening level decrease determination. Is. The learning correction of the counter learning value will be described in detail later.
The awakening level decrease learning unit 260 functions as the determination value learning unit of the present invention.

The alarm determination unit 310 determines whether or not an alarm to the driver is necessary based on a result of the arousal level determination by the arousal level determination device 200, and outputs a signal to the alarm device 320 when an alarm is necessary.
The alarm device 320 outputs an alarm for the driver in response to a signal from the alarm determination unit 310. As an alarm for the driver, for example, an alarm sound can be generated, an alarm lamp can be turned on or blinking, and vibration can be applied to the steering wheel 11 by the electric actuator 21.

Next, wakefulness determination in the wakefulness determination device 200 of the present embodiment will be described.
FIG. 2 is a flowchart showing an arousal level determination routine. Hereinafter, the steps will be described step by step.
<Step S01: Ignition Switch ON Determination>
The arousal level lowering learning unit 260 determines whether the ignition switch is turned on via the engine control unit 40. If the ignition switch is turned on, the process proceeds to step S02. Otherwise, the process skips step S02 and proceeds to step S03.

<Step S02: Flag reset>
The arousal level lowering learning unit 260 resets a flag that is turned on when a counter learned value, which will be described later, is subtracted (see step S13), and turns the flag off.
Thereafter, the process proceeds to step S03.

<Step S03: Traveling path detection of own vehicle>
The travel path detection unit 210 acquires information related to the road on which the host vehicle is currently traveling from the navigation device 60, and detects the travel path of the host vehicle.
Thereafter, the process proceeds to step S04.

<Step S04: Accumulation of Traveling Route History>
The history accumulating unit 220 accumulates information related to the travel path detected by the travel path detection unit 210 in step S03.
Thereafter, the process proceeds to step S05.

<Step S05: Discrimination of travel mode>
The travel mode determination unit 230 determines the travel mode on the travel path detected by the travel path detection unit 210 in step S03.
FIG. 3 is a flowchart showing a travel mode determination subroutine. Hereinafter, the steps will be described step by step.
<Step S51: Obtaining Traveling Route Information of Own Vehicle>
The travel mode determination unit 230 acquires information related to the travel path of the host vehicle from the travel path detection unit 210.
Thereafter, the process proceeds to step S52.
<Step S52: Highway discrimination>
The traveling mode determination unit 230 determines whether the traveling path of the host vehicle is an expressway, and proceeds to step S53 if it is an expressway, and proceeds to step S54 if it is a general road other than the expressway.
<Step S53: driving mode = “highway”>
The travel mode determination unit 230 determines that the current travel mode is “highway”, returns to the main routine, and proceeds to step S06.
<Step S54: Curve Curvature Determination>
The travel mode determination unit 230 compares the curve curvature of the travel path of the host vehicle with a predetermined value set in advance. If the curve curvature is greater than the predetermined value, the process proceeds to step S55, and if the curve curvature is less than the predetermined value. Proceed to step S56.
<Step S55: Travel Mode = “Curve”>
The travel mode determination unit 230 determines that the current travel mode is “curve”, returns to the main routine, and proceeds to step S06.
<Step S56: Travel Mode = “Line”>
The travel mode determination unit 230 determines that the current travel mode is “straight line”, returns to the main routine, and proceeds to step S06.

<Step S06: Handle angle detection>
The driving operation detection unit 240 detects the steering wheel angle and transmits the detected steering angle to the arousal level decrease determination unit 250 and the arousal level decrease learning unit 260.
Thereafter, the process proceeds to step S07.

<Step S07: Determination of steering wheel angle change>
The awakening level decrease determination unit 250 compares the change in the handle angle within a predetermined time with a predetermined value set in advance. If the change in the handle angle is smaller than the predetermined value, the process proceeds to step S09, and the change in the handle angle is greater than or equal to the predetermined value. If there is, the process proceeds to step S08.

<Step S08: Counter reset>
The awakening level decrease determination unit 250 resets the counter value of the above-described timer means (= 0).
Thereafter, the process proceeds to step S16.

<Step S09: Counter increment>
The arousal level decrease determination unit 250 increments the counter value of the timer means.
Then, it progresses to step S10.

<Step S10: Learning Condition Satisfaction Determination>
The awakening level decrease learning unit 260 determines whether a condition (learning condition) for learning correction of the counter learning value is satisfied.
FIG. 4 is a flowchart illustrating a subroutine for determining learning condition establishment. Hereinafter, the steps will be described step by step.
<Step S101: Travel Route History Search>
The awakening level decrease learning unit 260 uses the history storage unit 220 to search and acquire the travel history (the number of travels within a certain past period) of the travel route that matches the current travel route of the host vehicle.
Thereafter, the process proceeds to step S102.
<Step S102: History Count Determination>
The awakening level learning unit 260 compares the number of travels on the travel path searched in step S101 with a predetermined value set in advance. If the number of travels is greater than the predetermined value, the process proceeds to step S103, where the number of travels is predetermined. If it is less than or equal to the value, the process proceeds to step S105.
<Step S103: Operation Time Determination>
The arousal level lowering learning unit 260 compares the time from when the driver starts driving (after the vehicle starts running) with a predetermined value 1 and a predetermined value 2 (predetermined value 1 <predetermined value 2). If the operation time is larger than the predetermined value 1 and smaller than the predetermined value 2, the process proceeds to step S104. Otherwise, the process proceeds to step S105.
Here, the predetermined value 1 is set in consideration of a time during which the state of the driver is stabilized after the start of driving and the variation in the steering operation is reduced. The predetermined value 2 is set in consideration of the time during which the driving time becomes long and the variation in the steering operation increases due to driver fatigue or the like.
<Step S104: Satisfaction of learning conditions>
The awakening level decrease learning unit 260 determines that the learning condition is satisfied, returns to the main routine, and proceeds to step S11.
<Step S105: Learning conditions are not satisfied>
The awakening level decrease learning unit 260 determines that the learning condition is not satisfied, returns to the main routine, and proceeds to step S16.

<Step S11: Flag-off determination>
The awakening level decrease learning unit 260 detects the state of the flag described above. If the flag is off, the process proceeds to step S12. If the flag is on, the process skips steps S12 and S13 and proceeds to step S14.

<Step S12: Counter learning value subtraction>
The awakening level decrease learning unit 260 subtracts the counter learning value by a predetermined value in order to prevent the counter learning value from increasing without limit.
Thereafter, the process proceeds to step S13.

<Step S13: Flag On>
The arousal level lowering learning unit 260 turns on a flag indicating that the counter learning value has been subtracted.
Thereafter, the process proceeds to step S14.

<Step S14: Comparison between Counter and Counter Learning Value>
The arousal level lowering learning unit 260 compares the counter value of the timer means with the counter learned value corresponding to the current running mode, and if the counter value is larger than the counter learned value, the process proceeds to step S15, where the counter value is counter learned. If it is less than or equal to the value, step S15 is skipped and the process proceeds to step S16.

<Step S15: Counter learning value update>
The awakening level decrease learning unit 260 updates the counter learning value corresponding to the current travel mode used by the awakening level decrease determination unit 250 so as to be the same as the current counter value.
Thereafter, the process proceeds to step S16.

<Step S16: Comparison between Counter and Determination Value>
The awakening level decrease determination unit 250 compares the counter value with the determination value of the current traveling mode obtained by adding a predetermined value to the counter learning value of the current traveling mode. If the counter value is larger than the determination value, the awakening level is The process proceeds to step S17 by determining that it has decreased. If the counter value is equal to or smaller than the determination value, it is determined that the arousal level has not decreased, and a series of processing ends (returns).

<Step S17: Change steering assist>
The arousal level determination device 200 outputs a signal to the steering force control unit 140 of the steering assist device 100, increases the gain used for steering assist, increases the steering force with respect to a predetermined lateral deviation, and moves the host vehicle to the lane. Increase the level of support for running along the central driving target position.
Thereafter, the process proceeds to step S18.

<Step S18: Alarm activation>
The alarm determination unit 310 receives a signal from the arousal level determination device 200 and determines that an alarm output is necessary. The alarm device 320 receives a signal from the alarm determination unit 310 and starts outputting an alarm.
Thereafter, the series of processing is terminated (returned).

Further, the awakening level determination device 200 of the present embodiment corrects the counter value in the previous driving mode and takes over to the new driving mode at the time of transition of the driving mode (used for setting the counter value in the new driving mode). It has.
FIG. 5 is a flowchart showing a counter value setting routine at the time of running mode transition. Hereinafter, the steps will be described step by step.

<Step S201: Travel mode transition determination>
The awakening level decrease determination unit 250 compares the current travel mode with the previous travel mode. If they are different, the process proceeds to step S202 to correct the counter value. If they match, the process ends (return). )

<Step S202: Calculate Correction Coefficient C>
The awakening level decrease determination unit 250 calculates a coefficient C used for correcting the counter value by dividing the counter value of the previous mode by the learned value of the previous mode.
Thereafter, the process proceeds to step S203.

<Step S203: Correction of Previous Counter Value and Current Counter Value Calculation>
The awakening level decrease determination unit 250 sets a value obtained by multiplying the learning value of the current mode by the correction coefficient C obtained in step S202 as a counter value in the current mode, and executes a determination of awakening level decrease.
Thereafter, the process ends (returns).

According to the embodiment described above, the following effects can be obtained.
(1) The arousal level decrease learning unit 260 learns and corrects the counter learning value based on the history of the steering wheel angle when the number of times of traveling on the traveling path is equal to or greater than a predetermined value, thereby driving the driver on an unfamiliar road. It is possible to prevent inappropriate learning correction from being performed by the steering operation, and to perform appropriate learning correction and arousal level determination.
(2) The awakening level decrease learning unit 260 performs the learning correction of the counter learning value only when the elapsed time from the start of driving of the driver is larger than the predetermined value 1, thereby varying the steering operation even if the arousal level is high. It is possible to prevent inappropriate learning correction from being performed at the beginning of driving that is likely to occur, and to perform appropriate learning correction and arousal level determination.
(3) When the elapsed time from the start of driving of the driver is greater than or equal to the predetermined value 2, the arousal level decrease learning unit 260 prohibits the learning correction of the counter learning value, thereby easily affecting the driver's fatigue and the like. It is possible to prevent inappropriate learning correction from being performed based on the driving operation during time driving, and to perform appropriate learning correction and arousal level determination.
(4) The arousal level decrease determination unit 250 switches between a plurality of counter learning values corresponding to the expressway, curve, and straight line, and the awakening level decrease learning unit 260 travels when the handle angle history is acquired. By learning and correcting the counter learning value corresponding to the environment, the arousal level can be determined using an appropriate determination value in each traveling environment.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) In the embodiment, the steering operation amount of the driver is detected based on the change in the steering wheel angle. However, the present invention is not limited to this, and is detected based on, for example, the input torque from the steering wheel, that is, the steering force. Also good.
(2) The elapsed time from the start of driving by the driver is not limited to the time directly measured, but may be detected indirectly using, for example, the travel distance of the vehicle.
(3) The recognition of the driving environment is performed by acquiring information from the navigation device in the embodiment, but the present invention is not limited to this, for example, information acquired from environment recognition means having a stereo camera, for example, You may carry out based on vehicle state quantities, such as a vehicle speed, side G, a yaw rate, and a steering angle.
(4) The wakefulness determination device according to the embodiment is not limited to the use in combination with the steering assist device as in the embodiment, and can be applied to other uses such as an inter-vehicle distance setting for cruise control, for example.

It is a figure which shows the system configuration | structure of the vehicle which has the Example of the arousal level determination apparatus to which this invention is applied. It is a flowchart which shows the main routine of arousal level determination in the arousal level determination apparatus of FIG. It is a flowchart which shows the subroutine of driving | running | working mode discrimination | determination in FIG. It is a flowchart which shows the subroutine of learning condition satisfaction determination in FIG. It is a flowchart which shows the counter value setting routine at the time of driving | running | working mode transition in the arousal level determination apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Steering mechanism 11 Steering wheel 12 Steering shaft 13 Steering gear box 14 Tie rod FW Front wheel H Housing 20 Electric power steering (EPS) control unit 21 Electric actuator 22 Torque sensor 30 Stabilization control unit 31 Hydraulic control unit (HCU)
32 Vehicle speed sensor 33 Yaw rate sensor 34 Lateral acceleration (lateral G) sensor 35 Steering angle sensor 40 Engine control unit 50 Transmission control unit 60 Navigation device 70 Vehicle integration unit 100 Steering support device 110 Environment recognition unit 111 Stereo camera 112 Image processing unit 120 Target Traveling position setting unit 130 Vehicle traveling path estimation unit 140 Steering force control unit 200 Arousal level determination device 210 Traveling path detection unit 220 History accumulation unit 230 Driving mode determination unit 240 Driving operation detection unit 250 Arousal level decrease determination unit 260 Arousal level decrease Learning unit 310 Alarm judgment unit 320 Alarm device

Claims (6)

A wakefulness determination device that determines the wakefulness of a driver driving a vehicle,
Steering state detection means for detecting the steering operation amount or steering force of the driver;
Counter means for counting an elapsed time in a state where the steering operation amount or the steering force is a predetermined value or less;
Wakefulness decrease determination means for determining a driver's wakefulness decrease when the elapsed time is equal to or greater than a determination value;
Determination value learning means for performing learning correction of the determination value based on the driving state of the driver;
It is determined whether or not the host vehicle has traveled in the past on the road on which the host vehicle is traveling, and includes a travel number detecting means for detecting the number of travels,
The determination value learning means permits learning correction of the determination value based on the driving state when the number of times of travel is equal to or greater than a predetermined number of times, and determines the determination value when the number of times of travel is less than the predetermined number of times. A wakefulness determination device characterized by prohibiting learning correction. The awakening level determination according to claim 1, wherein the determination value learning means permits learning correction of the determination value only when an elapsed time from the start of driving of the driver is equal to or greater than a predetermined lower limit value. apparatus. A wakefulness determination device that determines the wakefulness of a driver driving a vehicle,
Steering state detection means for detecting the steering operation amount or steering force of the driver;
Counter means for counting an elapsed time in a state where the steering operation amount or the steering force is a predetermined value or less;
Wakefulness decrease determination means for determining a driver's wakefulness decrease when the elapsed time is equal to or greater than a determination value;
Determination value learning means for performing learning correction of the determination value based on the driving state of the driver,
The determination value learning means permits learning correction of the determination value based on the driving state when the elapsed time from the start of driving of the driver is equal to or greater than a predetermined lower limit value, and the elapsed time is less than the lower limit value. The learning level of the determination value is prohibited when the determination value is awakening level determination device. The determination value learning unit permits learning correction of the determination value only when an elapsed time from the start of driving of the driver is less than a predetermined upper limit value. Wakefulness determination device. The determination value is corrected by learning based on an elapsed time in a state where the steering operation amount or the steering force is equal to or less than a predetermined value in a state where learning correction of the determination value is permitted. The arousal level determination apparatus according to any one of claims 1 to 4. Driving environment recognition means for recognizing the driving environment of the host vehicle;
Determination value switching means for switching a plurality of the determination values according to the traveling environment,
The determination value learning means learns and corrects the determination value corresponding to the currently traveling environment when learning correction of the determination value is permitted. The arousal level determination apparatus according to any one of the above.

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