Wakefulness maintenance apparatus

A wakefulness maintenance apparatus includes a presentation recording unit and a presentation execution unit. The presentation recording unit records in-vehicle presentation contents each including a corresponding one of scenes, an auditory stimulus action associated with the scene, and at least one stimulus action selected from a group of a visual stimulus action, a tactile stimulus action, and an olfactory stimulus action which are associated with the scene. The presentation execution unit executes, based on the in-vehicle presentation contents recorded in the presentation recording unit, an in-vehicle presentation including provision of: the auditory stimulus action associated with the scene, and the at least one stimulus action selected from the group of the visual stimulus action, tactile stimulus action, and olfactory stimulus action which are associated with the scene.

BACKGROUND

Technical Field

The present disclosure relates to a wakefulness maintenance apparatus.

Background Art

Wakefulness of a driver is maintained by using a sensory stimulation such as sound.

SUMMARY

In one aspect of the present disclosure, there is provided a wakefulness maintenance apparatus including a presentation recording unit that records in-vehicle presentation contents each including: a corresponding one of scenes, an auditory stimulus action associated with the scene, and at least one stimulus action selected from a group of a visual stimulus action, a tactile stimulus action, and an olfactory stimulus action which are associated with the scene; and a presentation execution unit that executes, based on the in-vehicle presentation contents recorded in the presentation recording unit, an in-vehicle presentation including provision of: the auditory stimulus action associated with the scene, and the at least one stimulus action selected from the group of the visual stimulus action, tactile stimulus action, and olfactory stimulus action which are associated with the scene.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

PTL 1 discloses a technology of adjusting a driving environment by using a fluctuation sound, an aroma, and a color of decoration in a vehicle compartment and of matching a mental condition of a driver to an operating condition of a driving assistance apparatus.

It may be considered to maintain wakefulness of a driver by using a sensory stimulus such as sound. However, as a result of detailed study of the inventor, there is found a problem that since the driver is gradually accustomed to the sensory stimulus, it is difficult to maintain wakefulness of the driver by the conventional sensory stimulus. In one aspect of the present disclosure, it is preferable to provide a wakefulness maintenance apparatus capable of maintaining wakefulness of a driver.

The wakefulness maintenance apparatus as one aspect of the present disclosure can execute the in-vehicle presentation. The in-vehicle presentation includes application of an auditory stimulus action associated with the scene and at least one stimulus action selected from a group of a visual stimulus action, a tactile stimulus action, and an olfactory stimulus action which are associated with the scene, and thus a driver can be made to associate a scene with it. Therefore, cognitive activity of the driver increases and memory is recalled, and thereby the feeling is changed. That is, a higher-order function of a brain of the driver can be activated. As a result, the driver is less likely to become accustomed to the in-vehicle presentation and it is possible to maintain wakefulness of the driver.

Exemplary embodiments of the present disclosure will be described with reference to drawings.

First Embodiment

1. Configuration of Wakefulness Maintenance Apparatus1

The configuration of a wakefulness maintenance apparatus1will be described based onFIG. 1toFIG. 4. The wakefulness maintenance apparatus1is an on-vehicle apparatus mounted on a vehicle. The vehicle mounting the wakefulness maintenance apparatus1will be referred to as an own vehicle in the following. As shown inFIG. 1, the wakefulness maintenance apparatus1includes a control unit3, a recording unit5, and an input switch6. Note that the recording unit5corresponds to a presentation recording unit and a recording apparatus.

The control unit3is configured mainly by a well-known microcomputer having a CPU7and semiconductor memories (hereinafter, referred to as a memory9) such as a RAM, a ROM, and a flash memory. Various functions of the control unit3are implemented by the CPU7executing one or more programs stored in a non-transitory tangible recording medium. In this example, the memory9corresponds to the non-transitory tangible recording medium storing the program. In addition, when the program is executed, a method corresponding to the program is executed. Note that, the number of microcomputers constituting the control unit3may be one or more.

The control unit3, as a configuration of functions realized by the CPU7executing the program, as shown inFIG. 2, includes a presentation execution unit11, an image acquiring unit13, a presentation selection unit15, a wakefulness level estimating unit17, an effect estimating unit19, an effect overwriting unit21, an information acquiring unit25, a difficulty estimating unit27, a driving assistance determination unit29, a driving assistance unit31, and an IG determination unit33.

The method of realizing these elements constituting the control unit3is not limited to software, but a part or all of these elements may be realized by using one or more hardware components. For example, when the above-described functions are realized by an electronic circuit that is hardware, the electronic circuit may be realized by a digital circuit including many logic circuits, or an analog circuit, or a combination of these circuits.

The recording unit5records in-vehicle presentation contents. The in-vehicle presentation contents specify contents of in-vehicle presentation to be described below. Each of the in-vehicle presentation contents, as shown inFIG. 3andFIG. 4, is information associating a scene, an image, basic information, visual stimulus information, auditory stimulus information, tactile stimulus information, and olfactory stimulus information with each other. The recording unit5records a plurality of in-vehicle presentation contents. InFIG. 3andFIG. 4, one row represents one in-vehicle presentation content.

The scene means a location, a clock time, season, weather, an object in the periphery, and situation defined by human action or the like. Examples of the scene include “Hawaii beach”, “dusk in Okinawa”, “fishing boat in Japan Sea”, “fireworks in Atami”, “hand-held firework on veranda”, and “amusement park”.

The image is an image showing the associated scene. The basic information is information including a date and time of the scene, a location of the scene, a reproduction time of the in-vehicle presentation, and the like.

The visual stimulus information specifies a visual stimulus action provided in the in-vehicle presentation. The visual stimulus action is comprised of one or more light stimuli applied to a driver of the own vehicle. The visual stimulus information about the visual stimulus action, which specifies the visual stimulus action, includes, for example, a color of each light stimulus, a strength of each light stimulus, a pattern of time-series changes of the colors and/or strengths of the light stimuli, a start timing of application of the visual stimulus action, and the like. In addition, for example, when a plurality of devices that emit light are installed in the vehicle, a location or the like of each apparatus that emits light is also a factor for specifying the visual stimulus action. The visual stimulus action specified by the visual stimulus information is a visual stimulus action generated in the associated scene.

The auditory stimulus information specifies an auditory stimulus action provided in the in-vehicle presentation. The auditory stimulus action is comprised of one or more sound stimuli applied to a driver of the own vehicle. The auditory stimulus information about the auditory stimulus action, which specifies the auditory stimulus action, includes, for example, a loudness of each sound stimulus, a frequency of each sound stimulus, a pattern of time-series changes of the loudness and/or frequencies of the sound stimuli, a start timing of application of the auditory stimulus action, and the like. In addition, for example, when a plurality of devices that generate sound are installed in the vehicle, a location or the like of each apparatus that generates sound is also a factor for specifying the auditory stimulus action. Examples of the auditory stimulus action include one or more wave sounds, one or more chirp sounds of a wild bird or an insect, music, one or more engine sounds, and the like. The auditory stimulus action specified by the auditory stimulus information is an auditory stimulus action generated in the associated scene.

The tactile stimulus information specifies a tactile stimulus action provided in the in-vehicle presentation. The tactile stimulus action is comprised of one or more wind stimuli applied to a driver of the own vehicle. The tactile stimulus information about the tactile stimulus action, which specifies the tactile stimulus action, includes, for example, a strength of each wind stimulus, a direction of each wind stimulus, a pattern of time-series changes of the strengths and/or directions of the wind stimuli, a start timing of application of the tactile stimulus action, and the like. In addition, for example, when a plurality of devices that generate wind are installed in the vehicle, a location or the like of each apparatus that generates wind is also a factor for specifying the tactile stimulus action. Examples of the tactile stimulus action include one or more light winds, one or more strong winds, and the like. In addition, the tactile stimulus action may be a stimulus by vibration, pressure, temperature, or the like. The tactile stimulus action specified by the tactile stimulus information is a tactile stimulus action generated in the associated scene.

The olfactory stimulus information specifies an olfactory stimulus action provided in the in-vehicle presentation. The olfactory stimulus action is comprised of one or more aromatic stimuli applied to a driver of the own vehicle. The olfactory stimulus information about the olfactory stimulus action, which specifies the olfactory stimulus action, includes, for example, a type of each aromatic stimulus, a strength of each aromatic stimulus, a pattern of time-series changes of the types and/or strengths of the aromatic stimuli, a start timing of application of the olfactory stimulus action, and the like. In addition, for example, when a plurality of devices that generate aroma are installed in the vehicle, a location or the like of each apparatus that generates aroma is also a factor for specifying the olfactory stimulus action. Examples of the olfactory stimulus action include one or more sunscreen-flavored stimuli, one or more coconut-flavored stimuli, one or more sea-breeze-flavored stimuli, one or more ocean-flavored stimuli, and the like. The olfactory stimulus action specified by the olfactory stimulus information is an olfactory stimulus action generated in the associated scene.

Each of the in-vehicle presentation contents includes an order of starting provision (hereinafter, referred to as a stimulus order) of a visual stimulus action, an auditory stimulus action, a tactile stimulus action, and an olfactory stimulus action. Examples of the stimulus order include an order of starting provision of the visual stimulus action and auditory stimulus action at first and then starting provision of the tactile stimulus action and olfactory stimulus action.

In addition, for example, the stimulus order may be an order based on a strength of connection between each sensory stimulus and a scene. The strength of connection between each sensory stimulus and a scene, for example, uses as an index a probability or the like with which a scene can be specified by a single stimulus.

The recording unit5records a corresponding magnitude of awakening effect in association with an in-vehicle presentation content. The corresponding magnitude of awakening effect means a corresponding magnitude of effect of awakening a driver by executing the in-vehicle presentation. The corresponding magnitude of awakening effect is represented by the numerical value. The larger the numerical value is, the higher the awakening effect is.

The recording unit5can record an image. The driver can record an image into the recording unit5. Examples of the image recorded in the recording unit5include a camera image photographed by the driver. The recording unit5can record an image tag in association with an image. The image tag includes a date and time when the image was recorded, a location where the image was recorded, a name of a person who created the image, and the like.

In addition, the image tag includes information (hereinafter, referred to as driver preference information) tagged based on preference by the driver after photographing. The driver preference information indicates a corresponding magnitude of the preference level of the driver for an image. The driver preference information, for example, includes a type of a storage folder for classifying an image, an index of evaluation on an image itself, and the like. The image stored in a specific storage folder has a higher preference level of a driver than an image stored in another storage folder. In addition, the higher the index of evaluation on an image itself is, the higher the preference level of a driver is.

The input switch6is provided in a vehicle compartment of the own vehicle and receives an input operation of an occupant. The occupant operating the input switch6may be a driver or may be an occupant other than the driver. The input switch6corresponds to an input unit.

As shown inFIG. 1, the own vehicle includes, in addition to the wakefulness maintenance apparatus1, a camera35, an external apparatus39, a target sensor41, a navigation system43, a vehicle behavior sensor44, a display apparatus45, a speaker47, an air conditioner49, a diffuser51, and a driving assistance apparatus53.

The camera35photographs a range including a driver's face to generate an image (hereinafter, referred to as a face image). The camera35is attached to any of a steering column, a dashboard, a ceiling of a vehicle compartment, and the like of the own vehicle.

The external apparatus39is a apparatus capable of recording an image. The driver can record an image into the external apparatus39. Examples of the image recorded in the external apparatus39include a camera image photographed by the driver. Examples of the external apparatus39include a mobile terminal. Examples of the mobile terminal include a smartphone. The external apparatus39can record an image tag in association with an image. The image tag includes a date and time when the image was recorded, a location where the image was recorded, a name of a person who created the image, the driver preference information, and the like. Note that the external apparatus39corresponds to a recording apparatus.

The target sensor41detects a target existing around the own vehicle. Examples of the target include another vehicle, a pedestrian, and a feature. Examples of the target sensor41include an on-vehicle camera and a laser radar.

The navigation system43can acquire a location of the own vehicle, an environment of a road, traffic congestion information, and the like.

The vehicle behavior sensor44detects the behavior of the own vehicle. Examples of the behavior of the own vehicle include a speed, an acceleration, a yaw rate, an angle formed between a traveling direction of the own vehicle and a white line, and a relative position of the own vehicle with respect to a lane.

The display apparatus45is provided in a vehicle compartment of the own vehicle. The display apparatus45can provide a visual stimulus action to a driver of the own vehicle by irradiating light. The display apparatus45can change a color of light, a strength of light, an irradiation direction of light, presence or absence of blinking of light, an irradiation range of light, and the like.

The speaker47is provided in a vehicle compartment of the own vehicle. The speaker47can provide an auditory stimulus action to a driver of the own vehicle by outputting sound. The speaker47can change a loudness of sound, a frequency of sound, and the like.

The air conditioner49is provided in a vehicle compartment of the own vehicle. The air conditioner49can provide a tactile stimulus action to a driver of the own vehicle by jetting wind. The air conditioner49can change a strength of wind, a direction of wind, a temperature of wind, a humidity of wind, and the like.

The diffuser51is provided in a vehicle compartment of the own vehicle. The diffuser51can provide an olfactory stimulus action to a driver of the own vehicle by emitting aroma. The diffuser51includes many fragrances. The diffuser51can select one or more fragrances from among the many fragrances and emit aromas of the selected fragrances. That is, the diffuser51can change a type of aroma. In addition, the diffuser51can change also a strength of aroma.

The driving assistance apparatus53can perform driving assistance. Examples of the driving assistance include processing to warn the driver with sound, vibration, video, or the like when another vehicle approaching the own vehicle exists. In addition, examples of the driving assistance, when meandering, inappropriate speed fluctuation, or the like has occurred in the own vehicle, include processing to perform automatic steering and automatic speed adjustment in order to suppress them.

2. Processing Executed by the Wakefulness Maintenance Apparatus1

The processing executed by the wakefulness maintenance apparatus1will be described based onFIG. 5toFIG. 9. This processing is started, for example, when a predetermined operation is performed on the input switch6.

In Step1ofFIG. 5, the wakefulness level estimating unit17acquires a face image by using the camera35.

In Step2, the wakefulness level estimating unit17estimates a wakefulness level of a driver by using the face image acquired in the Step1. This processing will be described based onFIG. 6. In Step21ofFIG. 6, the wakefulness level estimating unit17extracts a region (hereinafter, referred to as a face region) occupied by the face of the driver in the face image.

In Step22, the wakefulness level estimating unit17extracts a feature amount of the face in the face region by a method of image analysis. The feature amount of the face is, for example, movement of an eyebrow, movement of an eyelid, movement of a mouth, or the like.

In Step23, the wakefulness level estimating unit17estimates a wakefulness level of the driver by collating the feature amount of the face extracted in the Step22with a database preliminarily recorded in the recording unit5. The wakefulness level is represented by a numerical value. The larger the numerical value of the wakefulness level is, the higher a degree of wakefulness of the driver is. The wakefulness level to be estimated here corresponds to a wakefulness level before execution of the in-vehicle presentation.

Returning toFIG. 5, in Step3, the wakefulness level estimating unit17determines whether the wakefulness level estimated in the Step2is equal to or more than a preset threshold value. The process proceeds to Step4when the wakefulness level is equal to or more than the threshold value, and proceeds to Step14when the wakefulness level is less than the threshold value.

In Step4, the information acquiring unit25acquires peripheral information by using the target sensor41and the navigation system43. Examples of the peripheral information include road environment around the own vehicle, traffic congestion state around the own vehicle, information on another vehicle and a pedestrian existing around the own vehicle, and the like.

In Step5, the difficulty estimating unit27estimates difficulty of driving by collating the peripheral information acquired in the Step4with a database preliminarily recorded in the recording unit5. The difficulty of driving is represented by a numerical value. As the numerical value of difficulty is larger, driving is difficult.

In Step6, the difficulty estimating unit27determines whether the difficulty of driving estimated in the Step5is equal to or less than a preset threshold value. The process proceeds to Step7when the difficulty of driving is equal to or less than the threshold value, and proceeds to Step14when the difficulty of driving exceeds the threshold value.

In Step7, the presentation selection unit15and the image acquiring unit13execute the in-vehicle presentation configuration processing. This processing will be described based onFIG. 7.

In Step31ofFIG. 7, the presentation selection unit15determines whether an input operation to designate an in-vehicle presentation content (hereinafter, referred to as a designation operation) has been performed on the input switch6. The process proceeds to Step32when the designation operation was performed, and proceeds to Step33when the designation operation was not performed.

In Step32, the presentation selection unit15selects the in-vehicle presentation content designated by the designation operation from among the in-vehicle presentation contents recorded in the recording unit5. Note that, the in-vehicle presentation content designated by the designation operation correspond to the input content.

In Step33, the image acquiring unit13performs processing to acquire an image from the external apparatus39or the recording unit5. At this time, the image acquiring unit13first performs processing to acquire an image in the external apparatus39. When an image to be acquired does not exist in the external apparatus39, the image acquiring unit13performs processing to acquire an image in the recording unit5. When a plurality of images are recorded in the external apparatus39or the recording unit5, the image acquiring unit13preferentially acquires an image having a higher driver preference level represented by the driver preference information.

For images for which the driver preference information does not exist, the image acquiring unit13preferentially acquires an image having a newer date and time when the image was recorded. When a plurality of images having the same driver preference level exist, the image acquiring unit13preferentially acquires an image having a newer date and time when the image was recorded among the images.

In Step34, the image acquiring unit13determines whether an image was able to be acquired in the Step33. The process proceeds to Step35when an image was able to be acquired, and proceeds to Step38when an image was not able to be acquired.

In Step35, the presentation selection unit15searches the recording unit5for a scene having a high degree of similarity with the image acquired in the Step33.

For example, the degree of similarity can be determined by comparing the result of automatic image analysis of the image acquired in the Step33with the scene recorded in the recording unit5. In addition, it can be determined by comparing an image tag attached to the image acquired in the Step33with the scene or basic information recorded in the recording unit5.

For example, it is assumed that an image shown inFIG. 8was acquired in the Step33. The presentation selection unit15performed automatic image analysis on this image and as a result acquired words of “sea” and “banana boat”. In this case, the presentation selection unit15can find out a scene of “Hawaii beach” as a scene having the highest degree of similarity and find out a scene of “ship deck” as a scene having the next highest degree of similarity in the scenes recorded in the recording unit5.

In addition, for example, it is assumed that an image shown inFIG. 9was acquired in the Step33. The presentation selection unit15performed automatic image analysis on this image and as a result acquired words of “mountain forest” and “rain”. As a result of search, a similar scene does not exist in the whole images shown inFIG. 9. In this case, the presentation selection unit15further searches for a scene similar to “mountain forest” and “rain”. The range of search may be the recording unit5, and an external storage medium may be searched through the Internet line or the like.

In Step36, the presentation selection unit15selects a scene having a relatively high degree of similarity with the image acquired in the Step33among the scenes recorded in the recording unit5based on the search result in the Step35. The number of scenes to be selected may be one or more.

In Step37, the presentation selection unit15selects an in-vehicle presentation content including the scene selected in the Step36from among the in-vehicle presentation contents recorded in the recording unit5.

The process proceeds to Step38when negative determination is made in the Step34. In Step38, the presentation selection unit15selects a presentation content having higher associated awakening effect as the wakefulness level estimated in the Step2is lower from among the in-vehicle presentation contents recorded in the recording unit5.

In Step39, the presentation selection unit15determines whether the wakefulness level estimated in the Step2is equal to or less than the predetermined threshold value. The process proceeds to Step40when the wakefulness level is equal to or less than the threshold value, and proceeds to Step41when the wakefulness level exceeds the threshold value.

In Step40, the presentation selection unit15makes the stimulus order in the in-vehicle presentation content selected in any of the Steps32,37, and38different from the stimulus order recorded in the recording unit5. The changed stimulus order may be decided at random or may be decided according to some rule.

In Step41, the presentation selection unit15decides the in-vehicle presentation content selected in any of the Steps32,37, and38as an in-vehicle presentation content used in later-described Step8. When the processing in the Step40is executed, the changed stimulus order is used in Step8.

Returning toFIG. 5, in Step8, the presentation execution unit11executes in-vehicle presentation on the basis of the in-vehicle presentation content decided in the Step7. The in-vehicle presentation is provision of the visual stimulus action, auditory stimulus action, tactile stimulus action, and olfactory stimulus action. When one in-vehicle presentation content is decided in the Step7, the presentation selection unit15provides the visual stimulus action, auditory stimulus action, tactile stimulus action, and olfactory stimulus action, according to the visual stimulus information, auditory stimulus information, tactile stimulus information, and olfactory stimulus information included in the one in-vehicle presentation content.

When two or more in-vehicle presentation contents are confirmed in the Step7, the presentation execution unit11combines the visual stimulus information, auditory stimulus information, tactile stimulus information, and olfactory stimulus information included in the two or more in-vehicle presentation contents to provide the visual stimulus action, auditory stimulus action, tactile stimulus action, and olfactory stimulus action. For example, when an in-vehicle presentation content A and an in-vehicle presentation content B are decided in the Step7, the presentation execution unit11can provide, for example, in-vehicle presentation of the in-vehicle presentation content A as the main in-vehicle presentation. However, it is possible to provide it by replacing only the visual stimulus action based on the visual stimulus information included in the in-vehicle presentation content A with the visual stimulus action based on the visual stimulus information included in the in-vehicle presentation content B.

In addition, the presentation execution unit11can simultaneously provide a visual stimulus action based on visual stimulus information included in the in-vehicle presentation content A and a visual stimulus action based on visual stimulus information included in the in-vehicle presentation content B. Alternatively, the presentation execution unit11can first provide a visual stimulus action based on visual stimulus information included in the in-vehicle presentation content A and then provide a visual stimulus action based on visual stimulus information included in the in-vehicle presentation content B.

In addition, when the image recorded in the external apparatus39or the recording unit5is a moving image, the presentation execution unit11may provide sound recorded in the moving image as an auditory stimulus action. Furthermore, the presentation execution unit11may provide change in light similar to change in color of the moving image as a visual stimulus action.

In Step9, the wakefulness level estimating unit17estimates a wakefulness level of a driver as in the Step2. The wakefulness level estimated in this Step9corresponds to a wakefulness level after execution of the in-vehicle presentation.

In Step10, the effect estimating unit19estimates an actual magnitude of awakening effect from the wakefulness level estimated in the Step2and the wakefulness level estimated in the Step9. As an increased amount of the wakefulness level estimated in the Step9with respect to the wakefulness level estimated in the Step2is larger, the awakening effect is estimated to be higher.

In Step11, the effect overwriting unit21overwrites the value of the actual magnitude of the awakening effect estimated in the Step10into a corresponding value of the magnitude of the awakening effect recorded in the recording unit5.

In Step12, the driving assistance determination unit29acquires the behavior of the own vehicle by using the vehicle behavior sensor44.

In Step13, the driving assistance determination unit29determines whether the driving assistance is necessary based on the wakefulness level estimated in the Step9and the behavior of the own vehicle acquired in the Step12. As the wakefulness level estimated in the Step9is lower, it becomes easier to determine that the driving assistance is necessary. As the behavior of the own vehicle acquired in the Step12deviates further from the normal range, it becomes easier to determine that the driving assistance is necessary. The process proceeds to Step14when it is determined that the driving assistance is necessary, and proceeds to Step15when it is determined that the driving assistance is not necessary.

In Step14, the driving assistance unit31instructs the driving assistance apparatus53to execute the driving assistance.

In Step15, the IG determination unit33determines whether an ignition of the own vehicle is on. The process proceeds to Step1when the ignition is on, and this processing is terminated when the ignition is off

3. Effects Exerted by the Wakefulness Maintenance Apparatus1

(1A) The wakefulness maintenance apparatus1can execute in-vehicle presentation. Since the in-vehicle presentation includes provision of visual stimulus action, auditory stimulus action, tactile stimulus action, and olfactory stimulus action associated with a scene, a driver can be made to associate the scene with it. Therefore, cognitive activity of the driver increases and memory is recalled, and thereby feeling is changed. That is, a higher-order function of a brain of the driver can be activated. As a result, the driver is harder to be accustomed to the in-vehicle presentation and it is possible to maintain wakefulness of the driver.

(1B) The wakefulness maintenance apparatus1acquires an image from the external apparatus39or the recording unit5. Then, the wakefulness maintenance apparatus1selects, from the in-vehicle presentation contents, one of the in-vehicle presentation contents, one of the scenes corresponding to the selected one of the in-vehicle presentation contents having a relatively high similarity to the image acquired. The wakefulness maintenance apparatus1executes the in-vehicle presentation on the basis of the selected in-vehicle presentation content. Therefore, the driver can be made to associate the scene with it more strongly. As a result, the driver is harder to be accustomed to the in-vehicle presentation and it is possible to further maintain wakefulness of the driver.

(1C) The wakefulness maintenance apparatus1preferentially acquires, in the Step33, an image having a higher preference level of a driver represented by the driver preference information. In addition, an image having a newer date and time when the image was recorded is preferentially acquired. Therefore, the driver can be made to associate the scene with it more strongly and to recall a memory vividly. As a result, the driver is harder to be accustomed to the in-vehicle presentation and it is possible to further maintain wakefulness of the driver.

(1D) The recording unit5records in-vehicle presentation contents in association with a corresponding magnitude of awakening effect. The wakefulness maintenance apparatus1estimates a first value of a wakefulness level of a driver. The wakefulness maintenance apparatus1selects, from the in-vehicle presentation contents recorded in the recording unit5, one of the presentation contents such that, the lower the first value of the wakefulness level of the driver, the larger the magnitude of awaking effect of the selected one of the presentation contents. Therefore, even when a wakefulness level of a driver is low, it is possible to increase the wakefulness level of the driver by executing an in-vehicle presentation having high awakening effect.

(1E) The wakefulness maintenance apparatus1estimates a second value of the wakefulness level after execution of the in-vehicle presentation. The wakefulness maintenance apparatus1estimates an actual magnitude of the awakening effect in accordance with the first value of the wakefulness level before execution of the in-vehicle dynamic presentation and the second value of the wakefulness level after execution of the in-vehicle dynamic presentation. The wakefulness maintenance apparatus1overwrites an estimated value of the actual magnitude of awakening effect into a corresponding value of the magnitude of the awakening effect recorded in the recording unit5. Therefore, it is possible to record an accurate magnitude of awakening effect in the recording unit5.

(1F) A first execution order of the stimulus action is stored in the presentation recording unit, and when the first value of the wakefulness level estimated by the wakefulness level estimating unit is equal to or less than a preset threshold value, the wakefulness maintenance apparatus1sets a second execution order of the stimulus action to be different from the first execution order recorded in the recording unit5. Therefore, an in-vehicle presentation whose unpredictability is high for a driver can be executed. As a result, wakefulness of the driver can be further maintained.

(1G) The wakefulness maintenance apparatus1selects, from the in-vehicle presentation contents recorded in the recording unit5, one of the in-vehicle presentation contents according to the input information received by the input switch6. Therefore, a driver can select an in-vehicle presentation content according to preference of the driver.

Other Embodiments

The embodiment of the present disclosure is described above, but the present disclosure is not limited to the above-described embodiment and can be variously modified and implemented.

(1) The in-vehicle presentation may be a combination of a plurality of presentation units. Each of the presentation units is a presentation including provision of an auditory stimulus action associated with one scene, and at least one stimulus selected from a group consisting of a visual stimulus action, a tactile stimulus action, and an olfactory stimulus action associated with the one scene. Note that, when the in-vehicle presentation includes one presentation unit, the one presentation unit is an in-vehicle presentation. The in-vehicle presentation in which a plurality of presentation units are combined, for example, can repeatedly create the processing of Step7by the number of the presentation units. The plurality of presentation units are provided in a predetermined order.

One of the scenes in presentation unit and another of the scenes in presentation unit may be the same or different from each other. A first scene in the scenes, corresponding to a first unit in the presentation units, and a second scene in the scenes, corresponding to a second unit in the presentation units, are dissimilar to each other, the second unit being immediately next to the first unit. In this case, it is possible to reduce occurrence of habituation of a sensory organ or psychological tiresomeness and to continue recalling memory.

Scenes are dissimilar to each other means that memories recalled by users who see the scenes displayed by a corresponding presentation unit are different from each other. An example in which first and second scenes are dissimilar to each other is a case where information about the first scene is different from the corresponding information about the second scene. The information about each of the first and second scenes can include at least one of the date and time of the corresponding one of the first and second scenes, and the place of the corresponding one of the first and second scenes.

An additional example in which first and second scenes are dissimilar to each other is a case where an average chromatic value and/or an average luminance value of an image corresponding to the first scene displayed in a dramatic representation unit is different from an average chromatic value and/or an average luminance value of an image corresponding to the second scene displayed in the same dramatic representation unit.

A further example in which first and second scenes are dissimilar to each other is a case where

(1) The types of one or more stimuli of at least one of the visual stimulus action, auditory stimulus action, tactile stimulus action, olfactory stimulus action, and the like previously set to the first scene are different from the types of one or more stimuli of at least one of the visual stimulus action, auditory stimulus action, tactile stimulus action, olfactory stimulus action, and the like previously set to the second scene, and/or

(2) The strengths of one or more stimuli of at least one of the visual stimulus action, auditory stimulus action, tactile stimulus action, olfactory stimulus action, and the like previously set to the first scene are different from the strengths of one or more stimuli of at least one of the visual stimulus action, auditory stimulus action, tactile stimulus action, olfactory stimulus action, and the like previously set to the second scene.

The wakefulness maintenance apparatus1can select and combine presentation units in which scenes are dissimilar to each other based on a data and time, a location, a tag, a result of automatic image analysis, and the like to create an in-vehicle presentation.

(2) The in-vehicle presentation may not provide one or two stimuli of the visual stimulus action, tactile stimulus action, and olfactory stimulus action.

(3) When a negative determination is made in the Step31, the process may always proceed to the Step38. Alternatively, the process may always proceed to the Step33without performing the determination in the Step31.

(4) The process may always proceed to the Step41after the Step37.

(5) A plurality of functions of one constituent element in the above-described embodiment may be realized by a plurality of constituent elements, or one function of one constituent element may be realized by a plurality of constituent elements. In addition, a plurality of functions of a plurality of constituent elements may be realized by one constituent element, or one function realized by a plurality of constituent elements may be realized by one constituent element. Further, a part of a configuration of the above-described embodiment may be omitted. Furthermore, at least a part of the configuration of the embodiment may be added to or replaced with another configuration of the above-described embodiment. Note that, every aspect included in technical thought specified from wording described in the Claims is an embodiment of the present disclosure.

(6) In addition to the above-described wakefulness maintenance apparatus1, the present disclosure can be realized by various forms, such as a system using the wakefulness maintenance apparatus1as a constituent element, a program causing a computer to function as the control unit3of the wakefulness maintenance apparatus1, a non-transitory tangible recording medium such as a semiconductor memory having recorded the program therein, and a wakefulness maintenance method.