JP2017174091A - Awakening keeping device and awakening keeping method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an awakening keeping device and an awakening keeping method, capable of keeping an awoken state of a user such as a driver of a vehicle while reducing laboriousness.SOLUTION: An awakening keeping device includes a stimulation presenting part (21) which presents a visual stimulation from an arbitrary position in a sight of field region of a user, and a control part (22) which controls the stimulation presentation part (21) so as to present the visual stimulation from a second position for specified illumination hours after a light-out period during which the visual stimulation is not presented after the visual stimulation is presented from a first position for specified illumination hours.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wakefulness maintaining device and a wakefulness maintaining method.

  Conventionally, there is a technique for irradiating a driver with light in order to maintain the awakening state of a driver such as a vehicle (Patent Document 1). In addition, there is a technique for maintaining an arousal state by inducing a driver's saccade eye movement (Patent Document 2).

JP 2008-146327 A JP2015-138383A

  However, the technique of Patent Document 1 has a problem that it is troublesome for the driver because the driver is irradiated with bright light. Further, the technique of Patent Document 2 is such that the stimulus is continuously displayed at two fixed left and right points, which is troublesome for the driver, and when the display is ignored by the driver, the effect of maintaining arousal is obtained. There is a problem that can not be.

  Therefore, an object of the present invention made in view of the above problems is to provide a wakefulness maintaining device and a wakefulness maintaining method capable of maintaining the wakefulness state of a user such as a vehicle driver while reducing annoyance. There is to do.

In order to solve the above-described problem, the wakefulness maintaining device according to the first aspect of the present invention includes:
A stimulus presentation unit that presents a visual stimulus from an arbitrary position within a user's visual field area;
After the visual stimulus is presented for a predetermined lighting time from the first position, the stimulus presenting unit is controlled so that the visual stimulus is presented for the predetermined lighting time from the second position after the turn-off time when no visual stimulus is presented. A control unit;
It is characterized by providing.

In addition, the wakefulness maintaining device according to the second aspect of the present invention includes:
The first position and the second position are different positions.

In addition, the wakefulness maintaining device according to the third aspect of the present invention includes:
The control unit changes the stimulus intensity of the visual stimulus over time within the predetermined lighting time.

In addition, the wakefulness maintaining device according to the fourth aspect of the present invention includes:
Provide a time change start time during the predetermined lighting time,
The control unit is characterized in that the stimulation intensity is gradually reduced from the start of the time change to the turn-off time.

In addition, the wakefulness maintaining device according to the fifth aspect of the present invention includes:
The control unit makes the time change rate of the stimulus intensity at the start of the predetermined lighting time larger than the time change rate of the stimulus intensity at the end of the predetermined lighting time.

In addition, the wakefulness maintaining device according to the sixth aspect of the present invention includes:
The control unit changes a stimulus intensity of the visual stimulus according to a position in the visual field region.

Moreover, the wakefulness maintaining device according to the seventh aspect of the present invention includes:
The control unit may change the stimulus intensity of the visual stimulus according to at least one of a vehicle speed and an automation level.

In addition, the wakefulness maintaining device according to the eighth aspect of the present invention includes:
A wakefulness detection unit that detects the wakefulness of the user,
The control unit changes a stimulus intensity of the visual stimulus according to the wakefulness detected by the wakefulness detection unit.

In addition, the wakefulness maintaining device according to the ninth aspect of the present invention includes:
The control unit changes the length of the predetermined lighting time according to the awake state detected by the awake state detection unit.

In addition, the wakefulness maintaining device according to the tenth aspect of the present invention includes:
The control unit changes the length of the turn-off time according to the wakefulness detected by the wakefulness detection unit.

In addition, the wakefulness maintaining method according to the eleventh aspect of the present invention includes:
A method for maintaining wakefulness in which a visual stimulus is presented from an arbitrary position within a user's visual field area,
A lighting step of presenting the visual stimulus from a first position for a predetermined lighting time;
After the lighting step, an extinguishing step that does not present a visual stimulus for a certain period of time;
After the extinguishing step, presenting the visual stimulus from a second position for a predetermined lighting time;
It is characterized by including.

  According to the wakefulness maintaining apparatus according to the first aspect of the present invention, it is possible to maintain the user's wakefulness state while reducing annoyance.

  Moreover, according to the wakefulness maintaining device according to the second aspect of the present invention, since the first position and the second position are different positions, the user's line-of-sight movement distance is increased, and the user's wakefulness state is further increased. It can be reliably maintained.

  Further, according to the wakefulness maintaining device according to the third aspect of the present invention, the user's wakefulness state can be more reliably maintained by changing the stimulus intensity of the visual stimulus within a predetermined lighting time.

  Moreover, according to the wakefulness maintaining device according to the fourth aspect of the present invention, the wakefulness state of the user can be more reliably maintained by gradually decreasing the stimulus intensity from the time change start time to the turn-off time. .

  Moreover, according to the wakefulness maintenance apparatus which concerns on the 5th viewpoint of this invention, a user's wakefulness state can be maintained more reliably by enlarging the rate of change of the stimulus intensity at the time of the start of lighting time.

  Moreover, according to the wakefulness maintenance apparatus which concerns on the 6th viewpoint of this invention, a user's wakefulness state can be maintained more reliably by changing irritation | stimulation intensity | strength according to the position in a visual field area | region.

  Moreover, according to the wakefulness maintenance apparatus which concerns on the 7th viewpoint of this invention, a stimulus intensity can be changed according to at least any one of a vehicle speed or an automation level, and a user's wakefulness state can be maintained more adaptively. .

  Moreover, according to the wakefulness maintenance apparatus which concerns on the 8th viewpoint of this invention, since the stimulation intensity | strength of the said visual stimulus is changed according to a wakefulness state, a user's wakefulness state can be maintained more adaptively.

  Further, according to the wakefulness maintaining device according to the ninth aspect of the present invention, the lighting time of the visual stimulus is changed according to the wakefulness state, so that the user's wakefulness state is more adaptively maintained while reducing annoyance. can do.

  Further, according to the wakefulness maintaining device according to the tenth aspect of the present invention, the extinction time of the visual stimulus is changed according to the wakefulness state, so that the user's wakefulness state is more adaptively maintained while reducing annoyance. can do.

  Moreover, according to the awakening maintenance method which concerns on the 11th viewpoint of this invention, a user's arousal state can be maintained more reliably, reducing annoyance.

It is a schematic diagram of the awakening maintenance apparatus concerning Embodiment 1 of the present invention. It is a block diagram of the controller of the awakening maintenance apparatus concerning Embodiment 1 of the present invention. It is a figure which shows a visual field area | region and a visual stimulus. It is a figure which shows the outline of the position which presents a visual stimulus. It is a figure which shows the outline of the lighting time of a visual stimulus, and the light extinction time. It is a flowchart which shows operation | movement of the wakefulness maintenance apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the time change of a visual stimulus. It is a figure which shows the reaction time in each area | region. It is a figure which shows the area | region corresponding to FIG. It is a schematic diagram of the awakening maintenance apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the wakefulness maintenance apparatus which concerns on Embodiment 2 of this invention.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described. In the first embodiment, as an example, a visual stimulus is presented by a so-called head-up display type device. FIG. 1 is a schematic diagram of a wakefulness maintaining device 1. The awakening maintenance device 1 includes a controller 2, a light source 3, an LCD 4, and a mirror 5. The controller 2 controls the display contents of the light source 3 and the LCD 4.

  The light source 3 projects light from behind so that the display on the LCD 4 has brightness. The LCD 4 displays an image of the display content set by the controller 2. The mirror 5 reflects the display light from the LCD 4 toward a predetermined position of the front windshield 6. The front windshield 6 may be provided with a semi-reflective member or the like so as to have a predetermined reflectance and transmittance. The instrument panel 8 above the mirror 5 is opened to allow display light to pass through.

  The wakefulness maintaining device 1 according to the first embodiment performs display in a relatively wide range of the front windshield 6 and applies a visual stimulus that is a virtual image in the forward visual field direction of a driver (hereinafter referred to as a user) operating the steering wheel 7. indicate. That is, the user sitting on the seat 9 visually recognizes the visual stimulus superimposed on the scenery (front field of view) viewed through the front windshield 6. The controller 2 may perform calculation and control of input from a navigation, a vehicle speed sensor, and the like. In this case, the controller 2 acquires information (hereinafter referred to as input information) from the navigation or the vehicle speed sensor directly or via in-vehicle communication.

  FIG. 2 is a block diagram of the controller 2 of the wakefulness maintaining device 1. The controller 2 includes a stimulus presentation unit 21, a control unit 22, and a storage unit 23.

  The stimulus presentation unit 21 presents a visual stimulus from an arbitrary position within the user's visual field region. Specifically, the stimulus presentation unit 21 presents visual stimuli at random positions so as to move the user's line of sight in the vertical and horizontal directions in order to maintain the user's arousal state.

  FIG. 3 is a diagram showing the visual field region 10 and the visual stimulus 11. The viewing area 10 is an area showing the user's field of view, and the vertical viewing angle is within 10 degrees and the horizontal viewing angle is about 25 degrees with respect to the forward linear direction from the position of the user's line of sight. Within the area. The visual stimulus 11 is a stimulus that can be visually recognized by the user, and is performed by, for example, displaying a figure, a character, a symbol, or a combination thereof. FIG. 3 illustrates a circular visual stimulus 11. In order to present the visual stimulus 11, the stimulus presentation unit 21 displays the display content related to the visual stimulus 11 on the LCD 4. The user visually recognizes the virtual image of the visual stimulus 11 superimposed on the front field of view seen through the front windshield 6.

  The control unit 22 presents the visual stimulus from a certain position A in the visual field region for a predetermined lighting time, and then presents the visual stimulus from the position B for a predetermined lighting time after the turn-off time. The unit 21 is controlled. The turn-off time is a time during which no visual stimulus is presented. The positions A and B correspond to the “first position” and the “second position” of the present invention, respectively.

  Then, the control unit 22 controls the stimulus presentation unit 21 so that the visual stimulus is presented from the position B for a predetermined lighting time and then the visual stimulus is presented from the position C for the predetermined lighting time after the turn-off time. . FIG. 4 is a conceptual diagram showing the visual stimuli 11A, 11B, and 11C at positions A, B, and C in the visual field region, respectively. As shown in FIG. 4, the position A, the position B, and the position C are different from each other. However, the position A, the position B, and the position C may all be the same position, or at least a part thereof may be the same position. Hereinafter, in the present embodiment, the visual stimulus is described as being presented at a position different from the previously displayed position.

FIG. 5 is a diagram showing an outline of lighting times and extinguishing times of visual stimuli. As shown in FIG. 5, a visual stimulus is presented at a certain position for a predetermined lighting time (T _on ). Thereafter, a turn-off time (T _off ) is provided. After the turn-off time, a visual stimulus is presented for a predetermined turn-on time (T _on ). After that, a turn-off time is provided again. In this manner, the visual stimulus is presented by alternately turning on and off. Specifically, for example, _Ton is 1 second, and for example, _Toff is also 1 second. The lengths of _Ton and _Toff are not limited to this. Moreover, _Ton and _Toff do not need to be the same length.

  The storage unit 23 stores various information used by the control unit 22 for control. For example, the storage unit 23 stores a value N that is incremented each time a visual stimulus is presented. The storage unit 23 stores the presentation position of the visual stimulus presented at the Nth time. Based on the presentation position of the (N-1) th visual stimulus stored in the storage unit 23, the control unit 22 determines a position different from the presentation position as the Nth presentation position. The stimulus presentation unit 21 presents a visual stimulus at the presentation position determined by the control unit 22.

  Next, the operation of the wakefulness maintaining apparatus 1 according to Embodiment 1 of the present invention will be described with reference to the flowchart shown in FIG.

  First, the control unit 22 initializes the value of N stored in the storage unit 23 (step S10). Specifically, the value of N is set to 1.

Next, the control part 22 determines the position where a visual stimulus is presented from within the visual field area of the user. The control unit 22 stores the determined position in the storage unit 23. The stimulus presenting unit 21 presents a visual stimulus at a position determined by the control unit 22 for a predetermined lighting time (T _on ) (step S20).

Subsequently, the control unit 22 turns _off the presentation of the visual stimulus during the turn-off time (T _off ) (step S30). Thereafter, the control unit 22 controls the stimulus presenting unit 21 to present the visual stimulus at a position different from the previous time (N-1th). The control unit 22 refers to the (N-1) th presentation position stored in the storage unit 23 and determines a position different from the presentation position as the scheduled position for the Nth visual stimulus. The control unit 22 stores the determined presentation position in the storage unit 23. Then, the stimulus presentation unit 21 presents the visual stimulus for a predetermined lighting time at the presentation position determined by the control unit 22 (step S40). Subsequently, the control unit 22 increments the value of N (step S50), returns to step S30, and repeats the processing from step S30 to step S50.

  As described above, according to the wakefulness maintaining device 1 according to the first embodiment, the turn-off time is provided between the turn-on times of the visual stimuli. As described above, since the visual stimulus is not always lit, the troublesomeness can be reduced as compared with the case where the visual stimulus is always lit at any place. Moreover, since the light-off time is provided, the user does not need to be constantly aware of the visual stimulus and can be concentrated by monitoring outside the vehicle. Furthermore, since the user unconsciously searches for the next visual stimulus to be displayed during the turn-off time of the visual stimulus, the line-of-sight movement distance becomes longer and the user's arousal state can be further maintained. Moreover, since the presentation position of the visual stimulus is different from the previous time, the user's line-of-sight movement distance can be ensured by a certain distance or more, and the user's arousal state can be further maintained.

  In step S40 in FIG. 6, the Nth visual stimulus is presented at a position different from the previous (N-1th) time, but the present invention is not limited to this. For example, the visual stimulus may be presented at a position different from the previous time (N-2th time). In this case, it is allowed to present a visual stimulus at the same position as the (N-1) th time. In this case, it is possible to prevent the visual stimulus from being presented at the same position three times in succession, and to prevent the user's line-of-sight movement distance from becoming short. It should be noted that how many times it is prevented to be presented at the same position can be arbitrarily set, and a visual stimulus may be presented at the same position N times or more (N ≧ 2).

  In step S40, the Nth visual stimulus is presented at a position different from the previous time. However, the present invention is not limited to this, and the visual stimulus may be presented outside a certain distance range from the previously presented position. In this way, by presenting the Nth visual stimulus outside the predetermined distance range from the previously presented position, the user's line-of-sight movement distance can be ensured by a certain distance or more, and the user's arousal state can be further maintained. .

  The intensity of visual stimulation (hereinafter referred to as stimulation intensity) may or may not be constant within the lighting time. Here, the stimulus intensity represents the intensity of the stimulus recognized by the user, and includes the brightness, size, color, contrast, or a combination thereof of the visual stimulus to be presented. For example, when the visual intensity is changed depending on the luminance, the control unit 22 increases the stimulation intensity by increasing the luminance. On the other hand, the control unit 22 lowers the stimulation intensity by lowering the luminance. Thus, the wakefulness maintaining apparatus 1 according to the present embodiment may change the stimulus intensity over time within a predetermined lighting time.

FIG. 7 shows an example in which the stimulus intensity of a visual stimulus within a certain lighting time is changed over time. In Figure 7, the time of lighting start of the visual stimulus and T _s, lit ends (at the beginning of the extinguishing time) it is set to T _e. As shown in FIG. 7, a time change start time (T _c1 ) is provided during a predetermined lighting time. Then, the stimulus intensity is gradually reduced after the start of the time change. Specifically, the control unit 22 of the controller 2 performs control so that the stimulus intensity gradually decreases from the time change start time (T _c1 ) to the light extinction time start time (T _e ).

In this way, by gradually changing the stimulus intensity with time toward the end of the lighting time (T _e ) of the visual stimulus, the search for the visual stimulus is promoted when the visual stimulus is turned off, and the user's arousal maintaining effect is improved. Can be increased.

In FIG. 7, but to reduce the stimulation intensity at a certain time rate of change from T _c1 toward T _e is not limited thereto, it may not be constant time rate of change. For example, the stimulus intensity may be attenuated exponentially.

Further, as shown in FIG. 7, the stimulus intensity is also changed at the start of the predetermined lighting time (between T _s and T _c2 ). And the rate of time change during the period is steep. Specifically, the control unit 22 uses the time change rate of the stimulus intensity at the start of the predetermined lighting time (time change rate of the stimulus intensity between T _s and T _c2 ) as the stimulus intensity at the end of the predetermined lighting time. It is controlled to be larger than the time rate of change (time change rate of the stimulation intensity between T _c1 from T _e).

Thus, by changing the stimulus intensity sharply at the start of the lighting time of the visual stimulus (T _s ), the line of sight moves from the search state when the visual stimulus is extinguished to the visual stimulus, and the user The awakening maintenance effect can be enhanced. In FIG. 7, the stimulus intensity is increased at a constant time change rate from T _s to T _c2 , but the present invention is not limited to this, and the time change rate may not be constant. For example, the stimulation intensity may be increased exponentially.

In FIG. 7, the stimulus intensity from T _c2 to T _c1 is constant, but is not limited thereto. You may make it change irritation | stimulation intensity | strength suitably also in the said period.

  Note that the stimulus intensity of the visual stimulus may be changed according to the position in the visual field region. FIG. 8 is a diagram illustrating a test result of a user's reaction time in each of the regions 10b including the front direction and the side direction of the vehicle. FIG. 9 is a diagram showing the position of the region 10b where the reaction time test was performed. As shown in FIG. 9, the region 10 b includes a user's visual field region 10. The area 10b is a rectangular area that is symmetrical with respect to the road vanishing point in FIG. FIG. 8A shows a test result of the reaction time of the user when the visual stimulus is presented in each area when the vehicle is stopped. The reaction time is the time required for the user to press the button provided for the test on the steering wheel 7 after presenting the visual stimulus. In FIG. 8, the front of the user is the origin of the xy coordinates, and the x-axis (horizontal axis) and the y-axis (vertical axis) are respectively horizontal with reference to the forward linear direction from the position of the user's line of sight. It represents the viewing angle in the direction and the vertical direction.

  As shown in FIG. 8A, the reaction time is generally shorter in the area in front of the user than in the area away from the user's front. In addition, when the presentation position of the visual stimulus changes in the vertical direction, the reaction time changes much more than when the presentation position changes in the horizontal direction. As shown in FIG. 9, the area 10b includes a front pillar. Therefore, the reaction time distribution is asymmetrical.

  Here, the higher the stimulus intensity, the more the user can recognize the visual stimulus in a shorter time. Therefore, the wakefulness maintaining apparatus 1 according to the present embodiment may change the stimulus intensity of the visual stimulus according to the position in the visual field region based on the change in the reaction time for each region. Specifically, the control unit 22 may increase the stimulation intensity as the reaction time is longer. This makes it easy to search for visual stimuli and enhance the arousal maintenance effect even in regions where the reaction time is relatively long (for example, near the top, bottom, left, and right ends of the visual field region). On the other hand, the stimulation intensity is lowered in a region (central portion) where the reaction time is relatively short. By doing in this way, the troublesomeness of visual stimulation can be reduced.

  In addition, the aspect of the change of the stimulation intensity is not limited to the above. For example, the stimulus intensity in the region where the reaction time is greater than or equal to a predetermined value may be made higher than the stimulus intensity in the region where the reaction time is less than the predetermined value.

  FIG. 8B and FIG. 8C are diagrams showing the reaction time in each region when the vehicle speed and the level of automatic driving of the vehicle are changed. FIG. 8B shows the reaction time when the vehicle speed is 40 km / h and the vehicle is traveling, and the automation level of automatic driving is level 2. FIG. FIG. 8C shows the reaction time when the vehicle speed is 40 km / h and the vehicle is traveling, and the automation level of the automatic driving is level 1. As shown in FIGS. 8B and 8C, the reaction time of each region changes when at least one of the vehicle speed and the level of automatic driving changes. As a rule of thumb, the reaction time increases as the vehicle speed increases. Also, the reaction time decreases as the level of automatic driving increases. The higher the level of automatic driving, the shorter the reaction time, because fewer tasks are required for driving and attention can be directed by monitoring visual stimuli.

  Here, the level of automatic operation is represented by level 0 to level 4. Level 0 is a state where the driver always performs all vehicle control. Level 1 is a vehicle having one or more specific maneuvering functions, and when a plurality of functions are automated, these functions operate independently of each other. In this case, the driver is assisted by the operation of one of the main control systems (either steering or brake / throttle, not both). The driver is not physically released from driving. Level 2 is a state in which at least two main control systems are automated, and these functions operate simultaneously. It frees the driver from controlling these functions. The difference between level 1 and level 2 is that in level 2, when the automatic operation mode is activated, the driver is physically released from operation. Level 3 is a state where it is possible to completely control the safety-critical functions to the vehicle under a specific traffic environment. In this case, the driver does not need to constantly monitor the traffic environment. Level 4 is a state in which all safety-critical driving functions are executed. In this case, the driver does not need to drive while driving.

  The arousal maintaining apparatus 1 according to the present embodiment provides the stimulus intensity of the visual stimulus in accordance with the change in the reaction time according to at least one of the vehicle speed and the automation level in addition to the change in the reaction time depending on the presentation position of the visual stimulus. It may be changed. That is, the stimulation intensity may be increased as the vehicle speed increases. Further, the stimulation intensity may be lowered as the level of automatic driving increases. Information related to the vehicle speed and the automatic driving level is included in the input information. Based on the input information, the control unit 22 changes the stimulation intensity of the visual stimulation according to at least one of the vehicle speed and the automation level. As described above, by changing the stimulation intensity according to at least one of the vehicle speed and the automation level, the user's arousal state can be more adaptively maintained. That is, when the reaction time of the user is short, such as when the vehicle speed is slow or when the automation level is high, the annoyance can be reduced by lowering the stimulation intensity. On the other hand, when the reaction speed of the user is long, such as when the vehicle speed is high or the automation level is low, the stimulus intensity can be increased to facilitate the user's stimulus search and enhance the arousal maintenance effect. .

  In addition, the aspect of the change of the stimulation intensity is not limited to the above. For example, the stimulation intensity when the vehicle speed is greater than or equal to a predetermined value may be made higher than the stimulation intensity when the vehicle speed is less than the predetermined value. Alternatively, the stimulation intensity when the automatic driving level is less than the predetermined level may be higher than the stimulation intensity when the automatic driving level is equal to or higher than the predetermined level. Moreover, although the change of the reaction time by the presentation position of a visual stimulus is also considered in the above, it is not restricted to this. You may make it change the stimulation intensity | strength of visual stimulation according to at least any one of a vehicle speed or an automation level irrespective of the presentation position of visual stimulation.

(Embodiment 2)
The second embodiment of the present invention will be described below. FIG. 10 is a schematic diagram showing the configuration of the wakefulness maintaining device 1b according to Embodiment 2 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. The wakefulness maintaining device 1b according to the second embodiment is different from the configuration according to the first embodiment in that the wakefulness maintaining device 1b includes a wakefulness detection unit 13 that detects a user's wakefulness.

  The wakefulness detection unit 13 illustrated in FIG. 10 is configured by a camera installed on the top of the steering column 12 and images the user's face through the steering wheel 7. The wakefulness detection unit 13 detects the user's wakefulness based on at least one of the number of times the user blinks, the length, and the face direction. The awake state detection unit 13 sends the detected awake state to the controller 2. The controller 22 of the controller 2 changes the stimulus intensity of the visual stimulus according to the arousal state detected by the arousal state detector 13. Specifically, the intensity of the visual stimulus is decreased as the degree of the user's arousal state is higher (awake state). On the other hand, the intensity of the visual stimulus is increased as the degree of awakening is lower.

  The operation of the wakefulness maintaining device 1b according to Embodiment 2 of the present invention will be described with reference to the flowchart shown in FIG. The same operations as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The control part 22 of the wakefulness maintenance apparatus 1b which concerns on Embodiment 2 adjusts the intensity | strength of visual stimulation after step S10 (step S15). Specifically, the stimulus intensity of the visual stimulus is appropriately changed according to the arousal state detected by the arousal state detection unit 13. The control unit 22 instructs the stimulation presenting unit 21 on the stimulation intensity. The stimulus presentation unit 21 presents a visual stimulus for a predetermined lighting time at the position determined by the control unit 22 with the stimulus intensity based on the instruction (step S20).

  Further, even after step S30, the control unit 22 adjusts the intensity of the visual stimulus (step S35). Specifically, the stimulus intensity of the visual stimulus is appropriately changed according to the arousal state detected by the arousal state detection unit 13. The control unit 22 instructs the stimulation presenting unit 21 on the stimulation intensity. The stimulus presentation unit 21 presents the visual stimulus for a predetermined lighting time at the position determined by the control unit 22 with the stimulus intensity based on the instruction (step S40).

  As described above, according to the wakefulness maintaining device 1b according to the second embodiment, the wakefulness detection unit 13 changes the stimulation intensity according to the user's wakefulness. Therefore, the user's awakening state can be maintained more adaptively.

  In addition, the aspect of the change of the stimulation intensity is not limited to the above. For example, the stimulation intensity when the degree of the user's arousal state is less than a predetermined value may be made higher than the stimulation intensity when the degree of the user's arousal state is a predetermined value or more.

  The configuration of the wakefulness detection unit 13 is not limited to the above. For example, the wakefulness detection unit 13 may be configured by a device that is worn on the user's earlobe, and the user's heart rate may be detected, and the wakefulness may be detected based on the detected heart rate. Further, the seat 9 may be provided with a wake-up state detection unit 13 to detect the user's heart rate and detect the wake-up state based on the detected heart rate. Alternatively, the wakefulness detection unit 13 may be configured by combining a plurality of these devices.

  Here, in order to function as the wakefulness maintaining device 1 and the wakefulness maintaining device 1b, a computer can be suitably used, and such a computer performs processing contents for realizing the functions of the wakefulness maintaining device 1 and the wakefulness maintaining device 1b. Is stored in a storage unit of the computer, and the program is read and executed by a central processing unit (CPU) of the computer.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each means, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of means, steps, etc. can be combined or divided into one. .

  For example, in the present embodiment, the stimulus is presented from an arbitrary position in the visual field area. However, the present invention is not limited to this, and an arbitrary position in the visual field area excluding the central visual area (hereinafter referred to as the peripheral visual area). Stimulus may be presented. Here, the central viewing area is an area in which the viewing angle in the vertical and horizontal directions is about 5 degrees with respect to the forward linear direction from the position of the user's line of sight.

In the present embodiment, the length of lighting time (T _on ) of the visual stimulus is described as a fixed time, but the present invention is not limited to this, and the length of lighting time may be changed. For example, depending on the arousal state of the user, as when a high arousal state, the control unit 22 of the arousal maintenance device 1b may be set shorter T _on. Or it may be set to be short as much as T _on the vehicle speed is slow. Or the level of automatic operation may be set shorter higher T _on. Further, for example, depending on the reaction time at a position of presenting the visual stimulus, the reaction time may be set short short positions as T _on. Or you may make the length of lighting time random.

In the present embodiment, the length of the turn-off time (T _off ) is described as a fixed time. However, the present invention is not limited to this, and the length of the turn-off time may be changed. For example, according to the user's arousal state, the control unit 22 of the arousal maintaining device 1b may set T _off shorter as the arousal state is higher. Alternatively, T _off may be set shorter as the vehicle speed is slower. Or it may be set T _off shorter the higher the level of automatic operation. Or you may make the length of light extinction time random. By doing so, the display timing of the next visual stimulus is not known, the search for the visual stimulus of the user can be promoted, and the arousal maintenance effect can be enhanced.

  Furthermore, the control unit 22 may change both the length of the lighting time and the length of the extinguishing time according to the awakening state. In addition, the control unit 22 may change the cycle (duty ratio) for turning on the visual stimulus by changing at least one of the length of the lighting time and the length of the turn-off time.

  Moreover, although this Embodiment demonstrated the case where the alertness maintenance apparatus 1 and the alertness maintenance apparatus 1b were provided in a vehicle, it is not limited to this. For example, you may provide in ships, aircrafts, etc. other than a vehicle. Moreover, you may make it use during the operation | work of PC by making the output destination which the stimulus presentation part 21 presents a visual stimulus into the display etc. of PC.

1, 1b Awakening maintenance device 2 Controller 3 Light source 4 LCD
DESCRIPTION OF SYMBOLS 5 Mirror 6 Front windshield 7 Steering wheel 8 Instrument panel 9 Seat 10 Field of view 10b Field 11, 11A, 11B, 11C Visual stimulus 12 Steering column 13 Arousal state detection part 21 Stimulus presentation part 22 Control part 23 Storage part

Claims (11)

A stimulus presentation unit that presents a visual stimulus from an arbitrary position within a user's visual field area;
After the visual stimulus is presented for a predetermined lighting time from the first position, the stimulus presentation unit is controlled so that the visual stimulus is presented for the predetermined lighting time from the second position after the extinguishing time when the visual stimulus is not presented A control unit,
A wakefulness maintaining device.   The wakefulness maintaining device according to claim 1, wherein the first position and the second position are different positions.   The wakefulness maintaining apparatus according to claim 1, wherein the control unit changes the stimulus intensity of the visual stimulus over time within the predetermined lighting time. Provide a time change start time during the predetermined lighting time,
The wakefulness maintaining apparatus according to claim 3, wherein the control unit gradually decreases the stimulation intensity from the start of the time change to the turn-off time.   The said control part makes the time change rate of the stimulation intensity | strength at the time of the start of the said predetermined lighting time larger than the time change rate of the stimulation intensity | strength at the time of the end of the said predetermined lighting time, It is characterized by the above-mentioned. A wakefulness maintaining device according to claim 1.   The wakefulness maintaining device according to any one of claims 1 to 5, wherein the control unit changes a stimulus intensity of the visual stimulus according to a position in the visual field region.   The wakefulness maintaining apparatus according to any one of claims 1 to 6, wherein the control unit changes a stimulus intensity of the visual stimulus according to at least one of a vehicle speed and an automation level. A wakefulness detection unit that detects the wakefulness of the user,
The wakefulness maintenance according to any one of claims 1 to 7, wherein the control unit changes a stimulus intensity of the visual stimulus according to the wakefulness detected by the wakefulness detection unit. apparatus.   The wakefulness maintaining apparatus according to claim 8, wherein the control unit changes a length of the predetermined lighting time according to the wakefulness state detected by the wakefulness state detection unit.   10. The wakefulness maintaining apparatus according to claim 8, wherein the control unit changes the length of the turn-off time according to the wakefulness state detected by the wakefulness state detection unit. A method for maintaining wakefulness in which a visual stimulus is presented from an arbitrary position within a user's visual field area,
A lighting step of presenting the visual stimulus from a first position for a predetermined lighting time;
After the lighting step, an extinguishing step that does not present a visual stimulus for a certain period of time;
After the extinguishing step, presenting the visual stimulus from a second position for a predetermined lighting time;
A method for maintaining wakefulness.