JP7127282B2 - Driving state determination device and driving state determination method - Google Patents

Description

The present disclosure relates to a driving state determination device and a driving state determination method.

2. Description of the Related Art In vehicles such as trucks, when a monotonous driving state continues, there is a concern that the driver's level of consciousness may be lowered and the driver may fall into a so-called careless driving state. In response to this, there has been proposed a device that determines whether or not the driving state is an inattentive driving state, and issues an alarm when it is determined that the driving state is the inattentive driving state (see Patent Document 1).

The above device determines whether or not the driver is inattentive driving based on the number of times the driver turns his/her face in a predetermined direction (eg, yaw direction or pitch direction) with respect to the direction of travel. The number of viewing actions is counted when the magnitude of the driver's face orientation angle (face orientation change amount) exceeds a predetermined value.

JP 2016-95571 A

By the way, when the driver changes his/her face to check the meter located on the lower side in the pitch direction, it is determined that the amount of change in face direction is large not only in the pitch direction but also in the yaw direction, depending on the posture in which the driver faces. As a result, there is a risk that the movement in the yaw direction will be detected in addition to the movement in the pitch direction.

Therefore, the present disclosure has been made in view of these points, and an object thereof is to suppress erroneous detection of a driver's viewing behavior.

In a first aspect of the present disclosure, a driving state determination device that determines whether or not the driver is in a careless driving state based on the number of visual recognition actions in which the driver visually recognizes a predetermined direction with respect to the traveling direction of the vehicle, a state acquisition unit that acquires a face orientation state of the driver; and a first angular velocity when the face orientation changes in a first direction and a face orientation in a second direction based on the face orientation state acquired by the state acquisition unit. an angular velocity acquisition unit that acquires a second angular velocity at the time of change; and when the first angular velocity exceeds a first reference value, it is counted as viewing behavior in the first direction, and the second angular velocity exceeds the second reference value. and a counting unit that counts as viewing behavior in the second direction when exceeding, wherein the counting unit is configured such that the first angular velocity exceeds a first threshold whose absolute value is larger than the first reference value, and Provided is a driving state determination device that, when the second angular velocity exceeds the second reference value, is counted as viewing behavior in the first direction, but is not counted as viewing behavior in the second direction.

In addition, when the first angular velocity exceeds the first reference value but does not exceed the first threshold value and the second angular velocity exceeds the second reference value, the counting unit detects the first direction and the viewing behavior in the second direction.

Further, the angular velocity acquisition unit acquires a forward angular velocity that is an angular velocity in a forward direction and a backward angular velocity that is an angular velocity in a backward direction when the driver reciprocates and visually recognizes the face in the first direction or the second direction. , and the counting unit may count as the visual behavior when the forward angular velocity and the backward angular velocity exceed respective corresponding threshold values.

Further, the first direction may be the pitch direction with respect to the traveling direction of the vehicle, and the second direction may be the yaw direction with respect to the traveling direction.

In a second aspect of the present disclosure, a driving state determination method for determining whether or not the driver is in a careless driving state based on the number of times the driver visually recognizes a predetermined direction with respect to the traveling direction of the vehicle, comprising: acquiring a face orientation state of the driver; calculating a first angular velocity when the face orientation changes in a first direction and a second angular velocity when the face orientation changes in a second direction based on the obtained face orientation state; obtaining, counting as viewing behavior in the first direction when the first angular velocity exceeds a first reference value, and counting in the second direction when the second angular velocity exceeds a second reference value and counting as visual recognition behavior in the counting step, wherein the first angular velocity exceeds a first threshold whose absolute value is larger than the first reference value, and the second angular velocity exceeds the second A driving state determination method is provided in which, when exceeding a reference value, it is counted as visual behavior in the first direction, but is not counted as visual behavior in the second direction.

Advantageous Effects of Invention According to the present disclosure, it is possible to suppress erroneous detection of visual recognition behavior of a driver.

1 is a block diagram showing an example of the configuration of a vehicle 1; FIG. FIG. 4 is a schematic diagram for explaining the relationship between the driver's facing direction and visual recognition behavior; FIG. 4 is a schematic diagram for explaining the relationship between the face orientation angle and the angular velocity; 4 is a flowchart for explaining the flow of driving state determination processing; FIG. 4 is a schematic diagram for explaining a region to which the face is facing;

<Vehicle configuration>
A configuration of a vehicle equipped with a driving state determination device according to the present disclosure will be described with reference to FIG.

FIG. 1 is a block diagram showing an example of the configuration of a vehicle 1. As shown in FIG. Vehicle 1 is a truck as an example. The vehicle 1 has an imaging device 4, an alarm device 8, and a control device 10, as shown in FIG.

The imaging device 4 is provided in the driver's seat (truck cab) of the vehicle 1 and includes, for example, a CCD camera. The imaging device 4 captures an image of the driver sitting in the driver's seat from the front to generate a captured image. For example, the image capturing device 4 captures an image of the driver's face while the vehicle 1 is running, and generates a captured image that can identify the driver's face orientation angle. The imaging device 4 outputs the generated captured image to the control device 10 .

The warning device 8 is a device that issues a warning to the driver when the driver is in a careless driving state. The alarm device 8 issues an alarm when the control device 10 determines that the vehicle is in a careless driving state. The alarm device 8 includes, for example, a speaker that sounds an alarm or the like, a display that displays a warning screen, and a vibration generator that generates vibration. Note that the alarm device 8 may issue an alarm by combining at least two of sound, display, and vibration.

The control device 10 controls operations of the imaging device 4 and the alarm device 8 . Further, in the present embodiment, the control device 10 functions as a driving state determination device that determines whether or not the driver is in a careless driving state. The inattentive driving state refers to, for example, a state in which the driver's level of consciousness is lowered due to continued monotonous driving on an expressway or the like. Specifically, it refers to a driving state in which attention is distracted, such as a state in which the driver does not look ahead carefully or a state in which the driver is dazed. The careless driving state is also a state where there is concern about the drowsy driving state.

The control device 10 determines whether or not the driver is driving in a careless driving state based on the number of times the driver visually recognizes a predetermined direction with respect to the traveling direction of the vehicle 1 (for example, a yaw direction or a pitch direction with respect to the traveling direction of the vehicle 1). Determine whether or not there is For example, the control device 10 determines that the driver is not in the careless driving state if the number of times of visual recognition behavior exceeds a predetermined value within a predetermined time, and determines that the driver is in the careless driving state if the number of visual behaviors is less than or equal to the predetermined value. do.

A visual recognition action is an action for the driver to confirm safety by turning his face in a predetermined direction. The driver normally looks at the direction of travel of the vehicle 1 through the windshield, but as a visual action for safety confirmation, the driver can act as follows, for example. Specifically, the driver visually recognizes the lower side of the meter panel of the vehicle 1, the right side of the vehicle 1 through the right side mirror, the right side of the vehicle 1 through the left side mirror, and the left side of the vehicle 1 through the left side mirror. Performs left-side visual recognition behavior that visually recognizes the rear. It is known that drivers of large vehicles such as trucks and buses move more and more often than ordinary passenger cars when they look at side mirrors and meter panels.

FIG. 2 is a schematic diagram for explaining the relationship between the driver's facing direction and visual recognition behavior. The driver D looks in the pitch direction (FIG. 2(a)) with respect to the traveling direction of the vehicle 1 and the yaw direction (FIG. 2(b)) with respect to the traveling direction. Specifically, the driver D turns his/her face to the lower side in the pitch direction (- side shown in FIG. 2(a)) to perform downward viewing action, and the left side in the yaw direction (to the left side in FIG. 2(b) By turning the face to the negative side shown), the left side visual recognition action is performed, and by turning the face to the right side (+ side) in the yaw direction, the right side visual recognition action is performed.

By the way, visual recognition behavior can be detected according to the amount of change in face direction when the face is turned in a predetermined direction. For example, when the driver turns his/her face downward in the pitch direction from the traveling direction, if the face direction change amount is larger than a predetermined value, it is counted as downward viewing behavior.
On the other hand, when the driver changes his/her face to check the meter located on the lower side in the pitch direction, it is determined that the amount of change in face direction is large not only in the pitch direction but also in the yaw direction, depending on the orientation of the driver's face. There is a risk that it will be detected as a visual recognition action in the yaw direction in addition to the visual recognition action in the pitch direction.

On the other hand, in the present embodiment, attention is paid to the fact that the angular velocity increases when the face direction changes when trying to check the meter or the like in the pitch direction. Although the details will be described later, when the angular velocity in the pitch direction becomes excessive, even if there is a change in the face orientation in the yaw direction, it is counted as a visual behavior only in the pitch direction (specifically, a downward visual behavior). . As a result, erroneous detection of the driver's viewing behavior can be suppressed.

<Detailed configuration of control device>
A detailed configuration of the control device 10, which is an operating state determination device, will be described with reference to FIG. The control device 10 has a storage unit 20 and a control unit 30, as shown in FIG.

The storage unit 20 includes, for example, ROM (Read Only Memory) and RAM (Random Access Memory). The storage unit 20 stores programs and various data for the control unit 30 to execute. In addition, the storage unit 20 stores information such as a threshold used for the driving state determination process.

The control unit 30 is, for example, a CPU (Central Processing Unit). The control unit 30 controls the driving state determination process by executing a program stored in the storage unit 20 . The control unit 30 includes a state acquisition unit 32, an angular velocity acquisition unit 33, a count unit 34, an operating state determination unit 35, and an alarm control unit 36, as shown in FIG.

The state acquisition unit 32 acquires the face orientation state of the driver. The state acquisition unit 32 acquires the face orientation state of the driver in the yaw direction and the pitch direction based on the captured image of the driver's face captured by the imaging device 4 . Specifically, the state acquisition unit 32 acquires a face orientation angle, which is an angle when the driver turns his face from the traveling direction to the yaw direction or the pitch direction. In this embodiment, the pitch direction corresponds to the first direction, and the yaw direction corresponds to the second direction.

The angular velocity acquisition unit 33 acquires the angular velocity when the driver changes the face orientation in a predetermined direction. The angular velocity acquisition unit 33 acquires an angular velocity when the face orientation changes in the yaw direction (also referred to as yaw angular velocity) and an angular velocity when the face orientation changes in the pitch direction (also referred to as pitch angular velocity). Specifically, the angular velocity acquisition unit 33 obtains the yaw angular velocity and the pitch angular velocity based on the facing state acquired by the state acquisition unit 32 .

The angular velocity acquisition unit 33 acquires a forward angular velocity, which is an angular velocity in the forward direction, and a backward angular velocity, which is an angular velocity in the backward direction, when the driver reciprocates and visually recognizes the face in the yaw direction or the pitch direction. For example, the angular velocity acquisition unit 33 acquires the forward angular velocity when turning the face to the right side (+ side) in the yaw direction from the traveling direction and the backward angular velocity when returning the face from the right side in the yaw direction to the traveling direction. Similarly, the angular velocity acquisition unit 33 acquires the forward angular velocity when turning the face to the left (- side) in the yaw direction from the advancing direction and the backward angular velocity when returning the face from the left side in the yaw direction to the advancing direction.

FIG. 3 is a schematic diagram for explaining the relationship between the face orientation angle and the angular velocity. The horizontal axis of the graph in FIG. 3 is time, and the vertical axis is angle or angle/unit time. A waveform G1 represents, for example, the transition of the face orientation angle in the yaw direction, and a waveform G2 represents the transition of the angular velocity obtained from the waveform G1. The + and - sides of FIG. 3 correspond to the + and - sides of FIG. 2(b). In FIG. 3, the angular velocity increases when the face angle is large, but when the face moves slowly, the angular velocity (angular velocity P5 in FIG. 3) decreases even if the face angle is large.

The counting unit 34 determines whether or not to count the change in face direction in the yaw direction or the pitch direction as a viewing action. First, the counting section 34 determines whether or not the yaw angular velocity and the pitch angular velocity acquired by the angular velocity acquiring section 33 exceed preset threshold values.

For example, when the yaw angular velocity exceeds the threshold value A, the counting unit 34 counts changes in the face orientation in the yaw direction as viewing behavior. Further, when the pitch angular velocity exceeds the threshold value B, the counting unit 34 counts the change in the face direction in the pitch direction as the viewing behavior. As a result, it is possible to appropriately determine the visual recognition behavior when the driver consciously performs the confirmation behavior.

In this embodiment, in addition to the threshold B, a threshold C whose absolute value is larger than the threshold B is set as the threshold of the pitch angular velocity. The threshold value C is set so that the pitch angular velocity exceeds the threshold value C when, for example, the driver is strongly aware of the meter and makes an action to check it. In this embodiment, the threshold B corresponds to the first reference value, the threshold A corresponds to the second reference value, and the threshold C corresponds to the first threshold.
When the pitch angular velocity exceeds the threshold value C and the yaw angular velocity exceeds the threshold value A, the counting unit 34 counts it as a visual action in the pitch direction, but does not count it as a visual action in the yaw direction. As a result, it is possible to prevent erroneous counting of the yaw direction viewing behavior when the driver is performing the viewing behavior in the pitch direction in order to check the meter panel.

On the other hand, when the pitch angular velocity exceeds the threshold value B but does not exceed the threshold value C and the yaw angular velocity exceeds the threshold value A, the counting unit 34 counts the visual action in the pitch direction and the visual action in the yaw direction. That is, the counting unit 34 counts the visual behavior in the pitch and yaw directions assuming that the driver faces in the pitch and yaw directions.

The counting unit 34 may count as a visual action when the forward angular velocity and the backward angular velocity as the yaw angular velocity or the pitch angular velocity are larger than the respective corresponding threshold values. The forward angular velocity threshold (first threshold) and the backward angular velocity threshold (second threshold) are set separately.

Here, a specific description will be given with reference to FIG. In FIG. 3, P1, P3, and P5 indicate forward angular velocities, and P2, P4, and P6 indicate backward angular velocities. Then, the counting unit 34 determines that the forward angular velocity of P1 exceeds the first threshold value and the backward angular velocity of P2 exceeds the second threshold value, and counts one as the visual action to the left in the yaw direction. Further, the counting unit 34 determines that the forward angular velocity of P3 exceeds the first threshold value and the backward angular velocity of P4 exceeds the second threshold value, and counts 1 as visual action to the right in the yaw direction.
By counting the visual recognition behavior using the forward angular velocity and the backward angular velocity as described above, the intentional change of the driver's face direction for safety confirmation etc. and the accidental change of the driver such as when the vehicle 1 curves Since it can be distinguished from a change in face orientation, it is possible to appropriately detect intentional viewing behavior.

The driving state determination unit 35 determines whether or not the driving state of the vehicle 1 is the careless driving state based on the number of visual recognition actions within a predetermined period of time. The driving state determination unit 35 determines that the driving state is inattentive when the number of visual actions counted by the counting unit 34 within a predetermined time (for example, the total number of visual actions in the yaw direction and the pitch direction) is equal to or less than a predetermined value. , and if the number of visual recognition actions is greater than a predetermined value, it is determined that the driver is not in a careless driving state.

The alarm control unit 36 causes the alarm device 8 to issue an alarm when the vehicle is in a careless driving state. When the driving state determination unit 35 determines that the vehicle is in a careless driving state, the warning control unit 36 causes the warning device 8 to issue a warning to warn the driver.

In the above description, two threshold values (threshold value B and threshold value C) are provided step by step in the pitch direction, but the present invention is not limited to this. For example, two thresholds may be provided in stages in the yaw direction to perform the above-described control.

<Operating state determination processing>
The flow of the driving state determination process will be described with reference to FIGS. 4 and 5. FIG. The driving state determination processing is realized by executing a program stored in the storage unit 20 by the control unit 30 of the control device 10 .

FIG. 4 is a flowchart for explaining the flow of the driving state determination process. FIG. 5 is a schematic diagram for explaining the area to which the face is facing. The flowchart in FIG. 4 starts, for example, when the vehicle 1 starts running.

First, the state acquisition unit 32 acquires the face orientation state of the driver during driving from the captured image of the imaging device 4 (step S102). Specifically, the state acquisition unit 32 acquires the face angle of the driver in the yaw direction and the pitch direction.

Next, the angular velocity acquisition unit 33 acquires the yaw angular velocity when the driver's face direction changes in the yaw direction and the pitch angular velocity when the driver's face direction changes in the pitch direction (step S104). Specifically, the angular velocity acquisition unit 33 obtains the yaw angular velocity and the pitch angular velocity from the face angle acquired by the state acquisition unit 32 .

Next, the counting unit 34 determines whether or not the yaw angular velocity is greater than the threshold A (step S106). For example, the counting unit 34 determines whether or not the forward angular velocity and the backward angular velocity when reciprocating the face in the yaw direction are larger than the threshold value A as the yaw angular velocity. If it is determined in step S106 that the yaw angular velocity is greater than threshold A (Yes), counting unit 34 determines whether or not the pitch angular velocity is greater than thresholds B and C (steps S108 and S110).

Then, when it is determined that the pitch angular velocity is greater than the threshold value C (step S110: Yes), the counting unit 34 counts it as a viewing action in the pitch direction (step S112). At this time, the driver is looking at the area R4 in FIG. 5, and the counting unit 34 counts one visual action only in the pitch direction.
On the other hand, when it is determined that the pitch angular velocity is greater than the threshold B but equal to or less than the threshold C (step S110: No), the counting unit 34 counts the visual recognition behavior in the pitch direction and the yaw direction (step S114 ). At this time, the driver is looking at the area R3 in FIG. 5, and the counting unit 34 counts 0.5 of the visual action in the pitch direction and the yaw direction, respectively.

If it is determined in step S108 that the yaw angular velocity is equal to or less than the threshold value B (No), the counting unit 34 counts it as visual action in the yaw direction (step S116). At this time, the driver is looking at the area R2 in FIG. 5, and the counting unit 34 counts one visual action only in the yaw direction.

Moreover, when it is determined that the yaw angular velocity is equal to or less than the threshold value A in step S106 (No), the counting unit 34 determines whether or not the pitch angular velocity is greater than the threshold value B (step S118). Then, when it is determined in step S118 that the pitch angular velocity is greater than the threshold value B (Yes), the counting unit 34 counts it as a viewing action in the pitch direction (step S120). At this time, the driver is looking at the area R1 in FIG. 5, and the counting unit 34 counts one visual action only in the pitch direction.

On the other hand, when it is determined that the pitch angular velocity is equal to or less than the threshold value B in step S118 (No), the counting unit 34 does not count the visual action in the yaw direction or the pitch direction (step S122). At this time, the driver looks at the area R0 in FIG. 5 (that is, the traveling direction of the vehicle).

After that, the driving state determination unit 35 determines whether or not the vehicle is in the careless driving state. For example, the driving state determination unit 35 determines that the vehicle is in the careless driving state when the number of visual actions counted within a predetermined period of time is equal to or less than a predetermined value. When it is determined that the vehicle is in the careless driving state, the alarm control unit 36 causes the alarm device 8 to issue an alarm.

<Effects of this embodiment>
In the above-described embodiment, the control device 10 counts the visual action in the yaw direction when the yaw angular velocity is greater than the threshold value A when the driver turns to face, and when the pitch angular velocity is greater than the threshold value B, the pitch angle velocity is greater than the threshold value B. Counts as directional sighting behavior. On the other hand, when the pitch angular velocity is greater than the threshold value C (greater than the threshold value B) and the yaw angular velocity is greater than the threshold value A, the control device 10 performs visual recognition behavior in the pitch direction (specifically, downward sighted behavior), but not counted as sighted behavior in the yaw direction.
For example, when the driver intentionally checks the instrument panel positioned below in the pitch direction, the pitch angular velocity is large. Therefore, when the pitch angular velocity is greater than the threshold value C, the control device 10 counts only the viewing behavior in the pitch direction even if the yaw angular velocity is greater than the threshold value A. As a result, it is possible to suppress erroneous detection of visual recognition behavior due to the driver's posture in which the driver's face is turned.

In the above description, based on the captured image of the driver's face captured by the imaging device 4, the driver's face-turning motion in the yaw direction and the pitch direction is acquired, but the present invention is not limited to this. For example, a gyro sensor may be used to acquire the facial movement of the driver in the yaw direction or the pitch direction. The gyro sensor is attached to the driver's hat or glasses.
Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various modifications or improvements can be made to the above embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

4 imaging device 10 control device 32 state acquisition unit 33 angular velocity acquisition unit 34 counting unit 35 driving state determination unit

Claims (4)

A driving state determination device that determines whether or not the driver is in a careless driving state based on the number of times the driver visually recognizes the pitch direction and the yaw direction with respect to the traveling direction of the vehicle,
a state acquisition unit that acquires the face orientation state of the driver;
an angular velocity acquisition unit that acquires a first angular velocity when the face orientation changes in the pitch direction and a second angular velocity when the face orientation changes in the yaw direction, based on the face orientation state acquired by the state acquisition unit;
When the first angular velocity exceeds the first reference value, it is counted as visual behavior in the pitch direction, and when the second angular velocity exceeds the second reference value, it is counted as visual behavior in the yaw direction. Department and
When the total number of counted visual actions in the pitch direction and the yaw direction is equal to or less than a predetermined value, it is determined that the vehicle is in a careless driving state. A driving state determination unit that determines that
with
The counting unit, when the first angular velocity exceeds a first threshold whose absolute value is larger than the first reference value and the second angular velocity exceeds the second reference value, the visual action in the pitch direction while not counting as viewing behavior in the yaw direction,
Driving state determination device. The counting unit, when the first angular velocity exceeds the first reference value but does not exceed the first threshold value and the second angular velocity exceeds the second reference value, the visual action in the pitch direction and counting as viewing behavior in the yaw direction;
The driving state determination device according to claim 1. The angular velocity acquisition unit acquires a forward angular velocity that is an angular velocity in a forward direction and a backward angular velocity that is an angular velocity in a backward direction when the driver reciprocates and visually recognizes the face in the pitch direction or the yaw direction,
The counting unit counts as the visual behavior when the forward angular velocity and the backward angular velocity exceed respective corresponding thresholds,
The driving state determination device according to claim 1 or 2. A driving state determination method for determining whether or not the driver is in a careless driving state based on the number of times the driver visually recognizes the pitch direction and the yaw direction with respect to the traveling direction of the vehicle,
a step in which the control unit of the vehicle acquires the face orientation state of the driver;
obtaining, based on the acquired face orientation state, a first angular velocity when the face orientation changes in the pitch direction and a second angular velocity when the face orientation changes in the yaw direction;
When the first angular velocity exceeds a first reference value, the control unit counts it as viewing behavior in the pitch direction, and when the second angular velocity exceeds a second reference value, the viewing behavior in the yaw direction is counted. a step that counts as an action;
The control unit determines that the driver is in a careless driving state when the total number of counted visual actions in the pitch direction and the yaw direction is equal to or less than a predetermined value, and determines that the driver is in a careless driving state when the total count is greater than the predetermined value. a step of determining that the vehicle is not in a careless driving state;
has
In the counting step, when the first angular velocity exceeds a first threshold whose absolute value is larger than the first reference value and the second angular velocity exceeds the second reference value, While counting as visual behavior in the pitch direction, not counting as visual behavior in the yaw direction;
Driving state determination method.

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