JP2017004043A - Driver state determination method and driver state determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driver state determination method and driver state determination device that allow a simple configuration to determine a drive ability of drivers with high accuracy by directly detecting a degree of concentration on drive operations.SOLUTION: A driver state determination device 1, which determines a drive state on the basis of drive operations of drivers, comprises: an in-vehicle CCD 5 that detects a movement in a vehicle width direction of a head of a driver; a lateral acceleration sensor 6 that detects a lateral acceleration; a storage unit 7b that stores reference amplitude A0 in the vehicle width direction of the head of the driver at the lateral acceleration at normal time; and a concentration level determination unit 7d that determines that a degree of concentration C of the driver is high as the amplitude A in the vehicle width direction of the head of the driver due to the lateral acceleration acted on the driver is smaller than the reference amplitude A0 corresponding to the lateral acceleration acted on the driver.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a driver state determination method and a determination apparatus for determining a driver state based on a driving operation by a driver.

2. Description of the Related Art Conventionally, there is known a driving support device that notifies a driver of a decrease in vehicle safety based on detection information of a running state (behavior) of a vehicle. For example, it recognizes the position of the host vehicle by capturing the left and right driving lanes with a camera when the vehicle is running, and issues a lane departure warning to alert the driver when it is determined that there is a possibility of lane departure. .
In such a lane departure warning device, the lane departure warning is activated even when the driver consciously travels in the end area of the center line or roadside line when traveling in a curve section, and the occupant feels uncomfortable or annoying. You may feel
In view of this, a technique for determining the state of mind and body of the driver and limiting unnecessary alarms has been proposed.

The driver state determination device disclosed in Patent Literature 1 is a low-frequency steering system that relates to a driver vibration characteristic that reflects a driver's head swing amount that reflects the driver's tension and a driver's operation characteristics that reflect the driver's activity. Mind and body information detecting means for detecting the angular velocity ratio, driving environment information means for detecting driving environment information, personal adapting means for determining personal information for adapting the mind and body state determination to the driver, driving environment information and personal information Determination threshold value determining means for determining the first to fourth determination threshold values based on the above, and the driver's mind-body condition is reduced in tension by the head vibration transmissibility, the low frequency steering angular velocity ratio, and the first to fourth determination threshold values. There is provided a psychosomatic state determining means for determining which state is a state, a relaxed state, an optimal tension state, an excessive tension state, or a fatigue state.
As a result, it is possible to determine a mental and physical state suitable for the individual driver, and it is possible to carry out driving assistance according to the driving ability deterioration situation.

By the way, it is also known that driving ability such as cognition and operability is closely related to driver's feeling during driving. And since emotions such as a sense of tension and a sense of security can be expressed as one vector on a dimension in psychology (dimensional theory), various emotion classification models have been proposed.
For example, in the emotional ring model of Russell, all the emotions are arranged in a ring shape on a plane with pleasure and activity as axes. In this model, tension is present in the second quadrant, which is an unpleasant / active category, and sense of security is present in the fourth quadrant, which is a so-called pleasant / inactive category, which is located opposite to the sense of tension. ing.

Japanese Patent No. 4581356

The driver state determination device of Patent Literature 1 calculates the head vibration transmissibility based on the acceleration in the vertical direction of the driver's head, so that the driver's vertical head vibration transmissibility increases. It is determined that the driver's tension is great.
However, the behavior of the driver's head is greatly influenced by the traveling state of the vehicle.
In other words, when the vehicle is traveling, the largest and most frequently occurring traveling state of the vehicle is a movement in the traveling direction in the vehicle width direction (left-right direction), which has a considerable effect on the vertical acceleration of the driver's head. Is expected to give Therefore, it is not easy to accurately extract the acceleration in the vertical direction of the driver's head excluding the influence of the movement in the vehicle width direction by the vehicle, and the driver's tension is determined with high accuracy. There is a possibility that it cannot be done.

In addition, the driver state determination device disclosed in Patent Document 1 includes a head vibration transmission rate related to the amount of head swing of the driver, which is a factor reflecting the magnitude of tension, and a driver's factor, which is a factor reflecting the degree of activity. Based on the low-frequency steering angular velocity ratio of the operation characteristics, a mental and physical state such as driver fatigue is determined.
However, tension is a factor related to both driver's emotional pleasure and activity, and it is said that moderate tension is preferable for driving. It does not have a correlation that can be clearly associated one-to-one.
That is, the driver state determination apparatus of Patent Document 1 indirectly detects the driver's concentration degree with respect to the driving operation using the driver's tension as a parameter, and accurately detects the concentration degree with respect to the driving operation. There is a possibility that it cannot be done.

  An object of the present invention is to provide a driver state determination method, a determination device, and the like that can determine a driver's driving ability with high accuracy with a simple configuration by directly detecting the degree of concentration with respect to driving operation. It is to be.

  According to a first aspect of the present invention, in the driver state determination method for determining the driver state based on the driving operation by the driver, a preparation for preparing a reference amplitude in the vehicle width direction of the driver's head based on a normal lateral acceleration A step of detecting an amplitude in a vehicle width direction of a driver's head due to a lateral acceleration acting on the driver, and a smaller amplitude than a reference amplitude corresponding to the lateral acceleration acting on the driver. And a determination step for determining that the concentration degree of the driver is high.

In this driver state determination method, in the detection step, since the amplitude in the vehicle width direction of the driver's head due to the lateral acceleration applied to the driver is detected, a stable operation of conscious visual field by the driver is simplified. Can be detected.
In the determination step, the driver's driving operation is performed using the driver's stable field of view as a parameter in order to determine that the driver's concentration is higher as the amplitude is smaller than the reference amplitude corresponding to the lateral acceleration applied to the driver. It is possible to directly detect the degree of conscious concentration with respect to.

  According to a second aspect of the present invention, there is provided a driver state determination device for determining a driving state based on a driving operation by a driver, a movement detecting means for detecting a movement of the driver's head in the vehicle width direction, and a lateral acceleration. Lateral acceleration detecting means for detecting; storage means for storing a reference amplitude in a vehicle width direction of the driver's head by a normal lateral acceleration; and a vehicle width of the driver's head by a lateral acceleration acting on the driver Concentration degree determining means for determining that the degree of concentration of the driver is higher as the direction amplitude is smaller than the reference amplitude corresponding to the lateral acceleration applied to the driver.

  Since this driver state determination device includes movement detection means for detecting the movement of the driver's head in the vehicle width direction, it is possible to detect a conscious visual stable operation by the driver with a simple configuration. Concentration degree determination that determines that the driver's concentration degree is higher as the amplitude in the vehicle width direction of the driver's head due to the lateral acceleration acting on the driver is smaller than the reference amplitude corresponding to the lateral acceleration acting on the driver. Since the means is provided, it is possible to directly detect the driver's conscious concentration degree with respect to the driving operation using the stable operation of the field of view as a parameter.

According to a third aspect of the present invention, in the second aspect of the present invention, the movement detecting means is an imaging means capable of imaging the head of the driver.
According to this configuration, it is possible to accurately detect the stable operation of the conscious visual field by the driver.

  According to the driver state determination method and the determination device of the present invention, the driving ability of the driver can be determined with high accuracy with a simple configuration by directly detecting the degree of concentration with respect to the driving operation.

1 is an external view of a vehicle including a driver state determination device according to a first embodiment. It is a functional block diagram of a driver | operator state determination apparatus. 6 is a correlation map between normal lateral acceleration and reference amplitude. It is a flowchart of a lane departure warning process. It is a flowchart of a determination threshold value setting process. It is a table | surface which shows the task of 1st verification experiment. It is a result of the first verification experiment, where (a) is intrinsic motivation, (b) is a sense of burden, (c) is a concentration degree related to driving, (d) is a margin, and (e) is a graph relating to a sense of security. It is. It is explanatory drawing of a 2nd verification experiment. It is a graph which shows a 2nd verification experiment result. It is another graph which shows a 2nd verification experiment result. It is another graph which shows a 2nd verification experiment result.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies a case where the present invention is applied to a vehicle V equipped with a driving support device, and does not limit the present invention, its application, or its use.

Embodiment 1 of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1 and 2, the vehicle V is disposed on a driver state determination device 1 that detects the degree of concentration of a driver's driving operation, and a roof front end portion or left and right door mirrors (not shown) in a vehicle interior. The vehicle is equipped with an out-of-vehicle CCD (Charge Coupled Device) 2 as a traveling state detection means, a lane departure warning device 3 as a driving support device, a warning device 4 and the like.
The driver state determination device 1 is a device that directly detects the conscious concentration degree C with respect to the driving operation of the driver by using the stable operation of the field of view by the driver as a parameter. It is a device that alerts the driver of the possibility of deviating from the lane (travel lane) and increases the sense of security for passengers including the driver by avoiding danger and reducing damage.
Hereinafter, the degree of concentration with respect to the driving operation of the driver is defined as a degree C of concentration.

First, the sense of security and the degree of concentration C used in the present invention will be described.
The sense of security is greatly divided into a passive sense of security that the driver is protected from the risk by the vehicle V (various equipment) and an active sense of security that allows the driver to drive the vehicle V and avoid the risk by herself. Can be separated. And in this invention, it aims at improving a passenger | crew's whole sense of security by expanding active sense of security among both senses of security.

Here, in order to clarify the factors affecting the active sense of security, an average driver was selected from two groups and a first verification experiment was performed.
Three types of traveling tasks for traveling on the circuit were given to the first group of subjects H1 and the second group of subjects H2, and a questionnaire was conducted after each of the traveling tasks.
As shown in FIG. 6, in the driving task, the driver factor (driving motivation) and the environmental factor (driving load) are different from each other, Task 1 “Please drive on the road”, Task 2 “Ensure safety and drive according to the speed limit of the course (120 km / h)”, Task 3 “Please drive according to the speed limit of the course (120 km / h) in consideration of fun” I taught.
As a result, Task 1 was set to have a low driving motivation and a driving load, Task 2 was set to be driving and a driving load, and Task 3 was set to have a high driving motivation and a driving load.
Subjects H1 and H2 answered subjective evaluations for five items after the running task: intrinsic motivation, sense of burden, concentration on driving, margin, and security. In answering, the normal (intermediate level) is set to 50.

Based on the graphs of FIGS. 7A to 7E, the first verification experiment result will be described.
The evaluation result of the subject H1 is indicated by a solid line, and the evaluation result of the subject H2 is indicated by a broken line.
As shown in FIGS. 7A to 7C, although the weight level varies depending on the subjects H1 and H2, the driver's concentration increases with the increase in intrinsic motivation and the feeling of burden.
As shown in FIGS. 7B and 7D, the margin decreases with an increase in the sense of burden.
As shown in FIGS. 7D and 7E, the greater the margin, the greater the sense of security.
As shown in the evaluation results of the subject H1 in FIGS. 7C to 7E, when the degree of concentration is low, the sense of security decreases even if the margin is high.
As a result, it has become clear that the driver's sense of security is proportional to the driver's degree of concentration with respect to driving operations.

Next, in order to clarify the correlation between the degree of concentration with respect to driving operation and the behavioral characteristics of the driver, a second verification experiment was performed.
In this verification experiment, in order to capture the feature quantity reflecting the concentration state of the average subject H3 (driver) of the first and second groups, the change in the head of the subject H3 when the subject H3 performs Tasks 1-3. Verifying.
As shown in FIG. 8, a plurality of observation points P are set on the head of the subject H3, and the movement amount of the head reference point G and changes in the facial expression of the subject H3 when Tasks 1 to 3 are executed are detected.

The second verification experiment result will be described based on FIGS.
As shown in FIG. 9, in Task 1 with a low degree of concentration, the amount of movement of the head in the vehicle width direction (left-right direction) accompanying the occurrence of lateral acceleration is large, and in Tasks 2 and 3 with a high degree of concentration, accompanying the occurrence of lateral acceleration. The moving amount of the head in the vehicle width direction is small.
As a result, it became clear that the driver's concentration is reflected in the shaking motion of the head in the vehicle width direction. This is considered to be because the more the driver concentrates, the more the consciousness to stabilize the field of view and the higher the perception accuracy works, and the muscles are strained to suppress the head from shaking with respect to the lateral acceleration.
In FIG. 10, the average opening degree of the eyelid of the test subject H3 in Task 1-3 is shown.
Since the vertical field of view increases as the eyelid opening increases, it is considered that the eyelid opening increases in order to obtain more distant information during concentration.
FIG. 11 shows the average distance (mouth width) between the mouth angles of the subject H3 in Tasks 1-3.
It is considered that the increase in the degree of concentration is reflected in the decrease in the distance between the mouth corners because there is a characteristic that the lips spread left and right when feeling bored.
As described above, it has been found that the degree of concentration of the driver with respect to the driving operation can be directly determined from the driving characteristics of the driver.

Returning to FIG. 1 and FIG. 2, the driver state determination device 1 will be described.
The following description includes a description of the driver state determination method.
As shown in FIGS. 1 and 2, the driver state determination device 1 includes an in-vehicle CCD 5 as a movement detection unit, a lateral acceleration sensor 6, a control device 7, and the like.
The in-vehicle CCD 5 is disposed on an instrument panel (not shown) and is fixed at a front position facing the driver. This in-car CCD 5 images the driver's head and facial expression.
The lateral acceleration sensor 6 is a sensor that detects the lateral acceleration of the vehicle V.
The in-vehicle CCD 5 and the lateral acceleration sensor 6 output detection results to the control device 7.

The control device 7 includes a CPU that executes a program, a ROM that stores the program, a RAM that temporarily stores data and programs, an EEPROM (electronically erasable and programmable read only memory), an input / output interface that inputs and outputs data, and the like. The driver's head amplitude (swing amount) A in the vehicle width direction detected by the lateral acceleration acting on the driver is detected. The smaller the amplitude A is than the normal reference amplitude A0, the higher the driver's concentration is. It is comprised so that it may determine.
As shown in FIG. 2, the control device 7 includes an amplitude recognition unit 7a, a storage unit 7b, a comparison unit 7c, a concentration degree determination unit 7d, and the like.

When the lateral acceleration is generated in the vehicle V, the amplitude recognizing unit 7a determines the driver's head reference point (for example, the middle position between the left and right eyes) based on the image signal of the driver's head imaged by the in-vehicle CCD 5. Amplitude A moved in the vehicle width direction with respect to the driver's front reference position can be calculated.
The amplitude recognizing unit 7a calculates the average opening degree of the driver's heel, the average distance between the mouth corners, and the like based on the image signal of the driver's facial expression captured by the in-vehicle CCD 5.

As shown in FIG. 3, the storage unit 7b stores a map M that defines the correlation between the normal lateral acceleration and the reference amplitude A0.
The map M is detected by a plurality of times in the vehicle width direction of the driver's head caused by the lateral acceleration when a predetermined lateral acceleration is normally applied to the driver. It is created based on the average value of the amplitude.
The map M may be formed for each vehicle speed of the vehicle V, and a plurality of maps M may be prepared for each traveling environment such as general roads, highways, weather, and terrain.

The comparison unit 7c compares the amplitude A by subtracting the amplitude A from the reference amplitude A0.
Before the difference between the reference amplitude A0 and the amplitude A, the amplitude A may be corrected by the average distance between the average opening of the bag and the mouth angle. Specifically, the greater the average opening degree of the bag and the smaller the average distance between the mouth corners, the higher the driver's concentration, and thus the value of the amplitude A is corrected to be smaller.

The concentration degree determination unit 7d and the like determine the concentration degree C for the driving operation of the driver based on the difference value between the amplitude A and the reference amplitude A0 caused by the same lateral acceleration as the amplitude A.
The concentration degree determination unit 7d determines that the concentration degree C of the driver is higher as the amplitude A is smaller than the reference amplitude A0. This is because, as described above, when the degree of concentration is high, the driver's consciousness to increase the perceptual accuracy works, and the muscles are tensioned to suppress the shaking of the head with respect to the lateral acceleration.

  Specifically, when the value obtained by subtracting the amplitude A from the reference amplitude A0 is equal to or less than zero, the concentration degree determination unit 7d or the like has a lower concentration degree with respect to the driving operation than the normal time (the concentration degree C is low). ), And when the value is greater than zero and equal to or less than the determination value K (0 <K), the driver determines that the degree of concentration with respect to the driving operation is higher than normal (concentration degree C is medium). Is larger than the normal time, the driver determines that the degree of concentration with respect to the driving operation is much higher (the degree of concentration C is higher). The determination result of the concentration degree C determined by the concentration degree determination unit 7d or the like is output to the lane departure warning device 3.

Next, the lane departure warning device 3 will be described.
The lane departure warning device 3 includes a CPU, a ROM, a RAM, an EEPROM, an input / output interface, and the like, and is configured to be able to determine the possibility that the vehicle V deviates from the lane.
As shown in FIG. 2, the lane departure warning device 3 includes a traveling lane recognition unit 3a, a departure determination unit 3b, a determination threshold setting unit 3c, and the like.

The traveling lane recognition unit 3a differentiates the brightness of the front image captured by the outside CCD 2 in the horizontal direction, thereby generating edges that are high frequency components at both ends of the white line on the traveling lane. The white line portion is estimated, and a white line is extracted from the estimated white line portion based on a threshold value determined from brightness and contrast with the road surface, a white line width threshold value, and the like.
The travel lane recognition unit 3a calculates the extracted white line information and the separation distance between the white line and the vehicle V.

Based on the calculation result by the travel lane recognition unit 3a, the departure determination unit 3b may cause the vehicle V to deviate from the travel lane when the degree of approach between the white line and the vehicle V approaches the determination threshold T. The operation command can be output to the alarm device 4 by determining.
When the determination threshold value T is large, the departure determination unit 3b is allowed to approach the white line by the vehicle V. Therefore, the departure determination unit 3b does not determine that there is a possibility of departure until the distance between the white line and the vehicle V becomes small. In addition, when the determination threshold T is small, the approach to the white line by the vehicle V is limited, and therefore it is determined that there is a possibility of departure even if the separation distance between the white line and the vehicle V is a certain large value.
It should be noted that an initial determination threshold value T0 is set in advance as the determination threshold value T at the start of traveling.

The determination threshold value setting unit 3c is configured to be able to change and set the determination threshold value T of the deviation determination unit 3b based on the concentration level C input from the concentration level determination unit 7d or the like.
The determination threshold value setting unit 3c makes the determination threshold value T when the driver's concentration degree C is high larger than the determination threshold value T when the concentration degree C is low.
This is because the driver's cognition (attention level) when the concentration degree C is high is higher than the driver's cognition when the concentration degree C is low.
The determination threshold value setting unit 3c sets the determination threshold value T when the concentration degree C is low as the first determination threshold value T1, the determination threshold value T when the concentration degree C is medium as the second determination threshold value T2, and when the concentration degree C is high. The determination threshold T is set to the third determination threshold T3 (T1 <T0 <T2 <T3).

When it is determined that the vehicle V may deviate from the traveling lane, the warning device 4 alerts the driver based on the operation command from the departure determination unit 3b.
For example, at least one of a speaker, a buzzer, and a display corresponds to the alarm device 4.

Next, a lane departure warning processing procedure by the lane departure warning device 3 will be described based on the flowcharts of FIGS.
Si (i = 1, 2,...) Indicates steps for each process.
As shown in FIG. 4, first, various information is read (S1), and the process proceeds to S2.
In S2, a determination threshold value setting process for setting a determination threshold value T for comparison with the degree of approach is performed. When the vehicle V starts to travel, an initial determination threshold value T0 is set.

After setting the determination threshold value T in S2, the process proceeds to S3, where it is determined whether or not the degree of approach between the vehicle V and the white line exceeds the determination threshold value T.
As a result of the determination in S3, if the degree of approach exceeds the determination threshold value T, the process proceeds to S4 in order to alert the driver, the alarm device 4 is activated, and then the process returns.
As a result of the determination in S3, when the degree of approach does not exceed the determination threshold T, the safety is not deteriorated, and the process returns without operating the alarm device 4.

Next, the determination threshold value setting process performed in S2 will be described in detail.
As shown in FIG. 5, it is first determined whether or not a lateral acceleration is generated in the vehicle V based on an input from the lateral acceleration sensor 6 (S11).
If the result of determination in S11 is that lateral acceleration has occurred, the amplitude A is calculated (S12), and the process proceeds to S13. If the result of determination in S11 is that lateral acceleration has not occurred, processing returns.
In S13, the degree of concentration C is determined based on the reference amplitude A0 and the determination value K, and the process proceeds to S14.

In S14, it is determined whether or not the concentration degree C is low.
If the degree of concentration C is low as a result of the determination in S14, the determination threshold T is set to the first determination threshold T1 (S15), and the process ends. As a result of the determination in S14, when the concentration degree C is not low, the process proceeds to S16 to determine whether or not the concentration degree C is medium.

  If the degree of concentration C is medium as a result of the determination in S16, the determination threshold T is set to the second determination threshold T2 (S17), and the process ends. If the degree of concentration C is not medium as a result of the determination in S16, the determination threshold T is set to the third determination threshold T3 (S18), and the process ends.

Next, the operation and effect of the driver state determination device 1 will be described.
According to the driver state determination device 1, since the in-vehicle CCD 5 that detects the movement of the driver's head in the vehicle width direction is provided, it is possible to detect a stable operation of the conscious visual field by the driver with a simple configuration. it can. It is determined that the driver's concentration degree C is higher as the amplitude A in the vehicle width direction of the driver's head due to the lateral acceleration acting on the driver is smaller than the reference amplitude A0 corresponding to the lateral acceleration acting on the driver. Since the concentration degree determination unit 7d is provided, the conscious concentration degree C with respect to the driving operation of the driver can be directly detected using the stable operation of the field of view by the driver as a parameter.

  Since the movement detecting means is the in-vehicle CCD 5 that can image the head of the driver, the conscious visual stable operation by the driver can be accurately detected.

Next, a modified example in which the embodiment is partially changed will be described.
1] In the embodiment, with the aim of reducing the control load, an example in which the driver's concentration degree is classified into three types of low, middle and high based on the determination value, and the determination threshold is adjusted according to this classification has been described. However, the determination threshold value may be linearly controlled according to the concentration level without classifying the concentration level.

2] In the above-described embodiment, an example in which the present invention is applied to a lane departure warning device has been described as a driving assistance device. It is also possible to apply to an excess warning device and an obstacle detection device.
In addition, when it is not a driving support device related to the driver's view direction, for example, in the case of a rear monitoring device that notifies a vehicle approaching from behind, the driver is concentrated with respect to the front view direction. There is a risk that the level of attention to the rear is reduced. Therefore, in a driving support device related to a direction other than the driver's field of view, it is preferable to prohibit a decrease in the alarm level or increase the alarm level even if the driver's concentration degree increases.

3] In the above embodiment, an example of a driving support device that directly supports driving operation has been described. However, the present invention may be applied to a driving support device that improves a mental state such as a driver's emotion.
In this case, for example, when a support device that improves the driver's driving motivation and emotions is activated by smell, music, lighting, etc., the driver's state determination device determines the concentration level, and an increase in the expected concentration level is obtained. If not, it can be applied to verification of effects such as changing the control of the support device and feedback control.

4) In addition, those skilled in the art can implement the present invention with various modifications added without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

1 Driver status determination device 5 Car CCD
6 Lateral acceleration sensor 7 Control device 7b Storage unit 7d Concentration degree determination unit

Claims (3)

In the driver state determination method for determining the driver state based on the driving operation by the driver,
A preparation step for preparing a reference amplitude in the vehicle width direction of the driver's head due to normal lateral acceleration;
A detection step of detecting an amplitude in a vehicle width direction of a driver's head due to a lateral acceleration acting on the driver;
A determination step of determining that the degree of concentration of the driver is higher as the amplitude is smaller than a reference amplitude corresponding to a lateral acceleration acting on the driver;
A driver state determination method characterized by comprising: In the driver state determination device that determines the driving state based on the driving operation by the driver,
Movement detection means for detecting movement of the driver's head in the vehicle width direction;
Lateral acceleration detecting means for detecting lateral acceleration;
Storage means for storing a reference amplitude in the vehicle width direction of the driver's head due to normal lateral acceleration;
It is determined that the degree of concentration of the driver is higher as the amplitude in the vehicle width direction of the driver's head due to the lateral acceleration acting on the driver is smaller than the reference amplitude corresponding to the lateral acceleration acting on the driver. Means for determining the degree of concentration,
A driver state determination device comprising:   The driver state determination apparatus according to claim 2, wherein the movement detection unit is an imaging unit capable of imaging the driver's head.