WO2023281977A1 - Wakefulness maintaining device and wakefulness maintaining method - Google Patents

Abstract

The present invention comprises: an occupant-related state identification unit (101) that identifies an occupant-related state, which is related to an occupant of a vehicle and includes at least the degree of drowsiness of the occupant; and a pulling control unit (104) that, if the degree of drowsiness of the occupant identified by a drowsiness identification unit (111) in the occupant-related state identification unit (101) is greater than or equal to a first threshold, causes a pulling stimulation that is generated by pulling the seat belt worn by the occupant. The pulling control unit (104) changes the mode of pulling stimulation in accordance with the occupant-related state identified by the occupant-related state identification unit (101).

Description

Awake maintenance device and wakefulness maintenance method Cross-reference to related applications

This application is based on Patent Application No. 2021-111687 filed in Japan on July 5, 2021, and the content of the underlying application is incorporated by reference in its entirety.

The present disclosure relates to a wakefulness maintenance device and a wakefulness maintenance method.

Patent Document 1 discloses a means for retracting a seat belt as a means for performing an actuation to encourage awakening.

JP 2009-261516 A

However, in Patent Document 1, only the pulling in of the seat belt is taken into consideration to promote wakefulness. Even if the seat belt is retracted in the same way, it may not be an appropriate stimulus depending on the condition of the seat belt and the condition of the subject. Therefore, in the technology disclosed in Patent Literature 1, there is a risk that the stimulus to maintain wakefulness by pulling in the seat belt may not be an appropriate stimulus for the subject.

One object of this disclosure is to provide a wakefulness maintenance device and wakefulness maintenance method that make it possible to make the wakefulness maintenance stimulus by pulling in the seat belt a more appropriate stimulus for the subject.

The above object is achieved by the combination of features described in the independent claims, and the subclaims define further advantageous embodiments of the disclosure. Reference numerals in parentheses in the claims indicate corresponding relationships with specific means described in embodiments described later as one mode, and do not limit the technical scope of the present disclosure.

To achieve the above object, a wakefulness maintenance device of the present disclosure is a wakefulness maintenance device that can be used in a vehicle. Based on the occupant-related state identification unit that identifies the state and the degree of drowsiness of the occupant identified by the occupant-related state identification unit that is equal to or greater than the first threshold, a stimulus is generated by pulling in the seat belt worn by the occupant. and an attraction control unit for performing a certain attraction stimulation, the attraction control unit changing the manner of the attraction stimulation according to the occupant-related state specified by the occupant-related state specifying unit.

To achieve the above object, a wakefulness maintenance method of the present disclosure is a wakefulness maintenance method that can be used in a vehicle, comprising: An occupant-related state identification step of identifying an occupant-related state, which is a state related to the occupant, and based on the fact that the degree of drowsiness of the occupant identified in the occupant-related state identification step is equal to or greater than a predetermined threshold, a pull-in control step for performing a pull-in stimulus, which is a stimulus due to pull-in of the seat belt, and in the pull-in control step, the mode of the pull-in stimulus is changed according to the occupant-related state specified in the occupant-related state specifying step.

According to these, based on the fact that the occupant's degree of drowsiness is equal to or higher than a predetermined threshold, the occupant's withdrawal stimulation, which is a stimulation caused by the withdrawal of the seat belt worn by the occupant, is performed, so it is possible to maintain wakefulness by the withdrawal stimulation. become. In addition, since the mode of the attraction stimulus is changed according to the occupant-related state, which is a state related to the occupant, the stimulus is more suitable for the subject than when the mode of the attraction stimulus is not changed regardless of the occupant-related state. it becomes possible to As a result, it is possible to make the stimulus for maintaining wakefulness by retracting the seat belt more suitable for the subject.

1 is a diagram showing an example of a schematic configuration of a wakefulness maintenance system 1; FIG. 1 is a diagram showing an example of a schematic configuration of an HCU 10; FIG. FIG. 10 is a diagram showing an example of shortening the interval between stimulations within one set of motive stimulations as the occupant's drowsiness level increases. FIG. 10 is a diagram showing an example in which the frequency of each set of the entrainment stimulus is increased as the drowsiness level of the occupant increases. 4 is a flowchart showing an example of the flow of wakefulness maintenance-related processing in the HCU 10. FIG. It is a figure which shows an example of a schematic structure of HCU10a. 4 is a flowchart showing an example of a flow of wakefulness maintenance-related processing for a fellow passenger in HCU 10. FIG. It is a figure which shows an example of a schematic structure of the wakefulness maintenance system 1b. It is a figure which shows an example of a schematic structure of HCU10b. It is a figure which shows an example of a schematic structure of HCU10c. FIG. 5 is a diagram for explaining an example of a motor current value according to how loose a seat belt is;

A plurality of embodiments for disclosure will be described with reference to the drawings. For convenience of explanation, in some embodiments, parts having the same functions as the parts shown in the drawings used in the explanation so far are denoted by the same reference numerals, and the explanation thereof may be omitted. be. The description in the other embodiments can be referred to for the parts with the same reference numerals.

(Embodiment 1)
<Schematic configuration of wakefulness maintenance system 1>
Hereinafter, this embodiment will be described with reference to the drawings. A wakefulness maintenance system 1 shown in FIG. 1 is used in an automobile (hereinafter simply referred to as a vehicle) and includes an HCU (Human Machine Interface Control Unit) 10, a seat ECU 20, an indoor camera 30, a display device 40, a seatbelt actuator 50, and a seat belt sensor 60 . For example, the HCU 10, the seat ECU 20, and the seat belt sensor 60 may be configured to be connected to an in-vehicle LAN (see LAN in FIG. 1). A vehicle using the wakefulness maintenance system 1 is not necessarily limited to an automobile as long as it uses a seat belt. A vehicle equipped with the wakefulness maintenance system 1 is hereinafter referred to as an own vehicle.

The seat ECU 20 is an electronic control unit that controls the seat environment, such as adjusting the seat position of the seat of the vehicle. For example, the seat ECU 20 adjusts the seat position by controlling a motor for adjusting the seat position of the vehicle (hereinafter referred to as a seat motor). Seat motors include a slide motor for adjusting the slide position and a reclining motor for adjusting the reclining position. The slide position indicates the adjusted position of the seat with respect to the longitudinal direction of the vehicle. The reclining position indicates the adjustment angle of the inclination of the seat back. The seat back corresponds to the backrest portion. Adjustment of the slide position and the reclining position may be performed according to the setting input from the occupant. A setting input from a passenger may be received via a switch or the like, for example. Also, the seat ECU 20 sequentially detects the slide position and the reclining position. The slide position may be detected, for example, from the rotation angle of the slide motor. The reclining position can be detected from the rotation angle of the reclining motor.

In this embodiment, a case in which the slide position and the reclining position are electrically adjustable will be described as an example, but this is not necessarily the case. For example, some or all of the slide position and reclining position may not be electrically adjustable and may require manual adjustment. If the slide position is not electrically adjustable, the slide position may be detected by a sensor that detects the slide position. If the reclining position is not electrically adjustable, the reclining position may be detected by a sensor that detects the reclining position.

The indoor camera 30 captures an image of a predetermined range inside the vehicle. It is assumed that the indoor camera 30 captures an image of a range including at least the driver's seat of the own vehicle. The indoor camera 30 may capture an image of a range including the driver's seat, the front passenger's seat, and the rear seats of the own vehicle. A plurality of cameras may be used as the indoor camera 30, and the imaging range may be shared by the plurality of cameras. The indoor camera 30 includes, for example, a near-infrared light source, a near-infrared camera, and a control unit for controlling them. The indoor camera 30 captures an image of the occupant irradiated with near-infrared light by the near-infrared light source. In the present embodiment, the indoor camera 30 will be described as capturing an image of at least the driver in the driver's seat. An image captured by the near-infrared camera is image-analyzed by the control unit. The control unit detects the opened/closed state of the occupant's eyelids, face orientation, line-of-sight direction, arousal level, posture, etc., based on the occupant feature amount extracted by image analysis of the captured image. The degree of arousal may be detected by, for example, the degree of opening and closing of the eyelids.

The presentation device 40 is installed in the vehicle and presents information to the interior of the vehicle. The presentation device 40 presents information according to instructions from the HCU 10 . The presentation device 40 may present information at least to the driver. The presentation device 40 may present information to fellow passengers other than the driver. The presentation device 40 includes a display 41 and an audio output device 42 .

The display 41 presents information by displaying information. As the display 41, for example, a meter MID (Multi Information Display), CID (Center Information Display), HUD (Head-Up Display) can be used. The meter MID is a display device provided in front of the driver's seat in the passenger compartment. As an example, the meter MID may be configured to be provided on the meter panel. The CID is a display device placed in the center of the instrument panel of the vehicle. The HUD is provided, for example, on an instrument panel inside the vehicle. The HUD projects a display image formed by the projector onto a predetermined projection area on the front windshield as a projection member. The image light reflected by the front windshield to the interior of the vehicle is perceived by the driver seated in the driver's seat. As a result, the driver can visually recognize the virtual image of the display image formed in front of the front windshield overlapping a part of the foreground. The HUD may be configured to project the display image onto a combiner provided in front of the driver's seat instead of the front windshield. The audio output device 42 presents information by outputting audio. A speaker or the like can be used as the audio output device 42 .

The seatbelt actuator 50 feeds and retracts the seatbelt of the vehicle. Retraction of the seat belt causes retraction of the seat belt. In this embodiment, the occupant wearing a seat belt is stimulated by the retraction of the seat belt to keep them awake. The seat belt actuator 50 is, for example, a motor. The seatbelt actuator 50 feeds and retracts the seatbelt of the own vehicle according to instructions from the HCU 10 . The seat belt actuator 50 is provided at least in the driver's seat. Note that the seat belt actuator 50 may be configured to be provided for each seat.

The seatbelt sensor 60 is a sensor that detects the amount of withdrawal of the seatbelt by the seatbelt actuator 50 . For example, the seat belt sensor 60 may be an encoder that detects the rotation angle of the seat belt actuator 50 as a motor. In this case, this rotation angle may be treated as the withdrawal amount of the seat belt.

The HCU 10 is mainly composed of a microcomputer equipped with a processor, memory, I/O, and a bus connecting them. The HCU 10 executes a control program stored in the memory to execute various types of processing such as processing related to keeping the occupants of the own vehicle awake (hereinafter referred to as “wakefulness maintenance related processing”). This HCU 10 corresponds to a wakefulness maintenance device. Memory, as used herein, is a non-transitory tangible storage medium for non-transitory storage of computer-readable programs and data. A non-transitional physical storage medium is implemented by a semiconductor memory, a magnetic disk, or the like. A schematic configuration of the HCU 10 will be described below.

<Schematic configuration of HCU 10>
Next, a schematic configuration of the HCU 10 will be described with reference to FIG. 2 . As shown in FIG. 2, the HCU 10 includes an occupant-related state identification unit 101, a presentation control unit 102, an optimum determination unit 103, and a pull-in control unit 104 as functional blocks. Execution of the processing of these functional blocks by the computer corresponds to execution of the wakefulness maintaining method. A part or all of the functions executed by the HCU 10 may be configured as hardware using one or a plurality of ICs or the like. Also, some or all of the functional blocks provided by the HCU 10 may be implemented by a combination of software executed by a processor and hardware members.

The occupant-related state identification unit 101 identifies a state related to the occupants of the own vehicle (hereinafter referred to as occupant-related state). The processing in the occupant-related state identification unit 101 corresponds to the occupant-related state identification step. The occupant-related state identification unit 101 has a drowsiness identification unit 111, a slackness identification unit 112, and a physique identification unit 113 as sub-functional blocks.

The drowsiness identification unit 111 identifies the degree of drowsiness of the occupant of the vehicle. The drowsiness identifying unit 111 may identify the degree of drowsiness from the awakening level detected by the indoor camera 30 . Note that the degree of drowsiness may be specified by the drowsiness specifying unit 111 from the image captured by the indoor camera 30 without detecting the awakening level with the indoor camera 30 . As an example, the drowsiness identification unit 111 identifies drowsiness levels classified into six stages described below. For example, sleepiness levels may be classified according to the NEDO evaluation method.

A drowsiness level of 0 is the degree of not being sleepy at all (Not Sleepy). Drowsiness level 0 can be rephrased as wakefulness. The characteristics of drowsiness level 0 include the following. First, the movement of the line of sight is fast and frequent. The second is that the cycle of blinking is stable. The third is that it involves physical movement. Sleepiness level 1 is the degree corresponding to Slightly Sleepy. The drowsiness level 1 or more can also be rephrased as a non-awakened state. The characteristics of sleepiness level 1 include the following. The first is that the lips are open. The second is that the movement of the line of sight is slow. Sleepiness level 2 is the degree of sleepiness. The characteristics of drowsiness level 2 include the following. The first is slow and frequent blinking. The second is that there is movement of the mouth. The third is that you can see the re-sitting in the seat. The fourth is that the gesture of putting a hand on the face can be seen. The division between sleepiness level 2 or higher and sleepiness level less than 2 can also be rephrased as a division of whether or not the subject is aware of sleepiness. A drowsiness level of 2 or higher is a category in which the subject perceives drowsiness. A sleepiness level of less than 2 is a category in which the subject does not perceive sleepiness.

Drowsiness level 3 is the degree of rather sleepy. The characteristics of sleepiness level 3 include the following. The first is that there are blinks that are presumed to be conscious. Second, unnecessary body movements such as shaking the head and moving the shoulders up and down are observed. The third is frequent yawning and deep breathing. The fourth is that the blink and the movement of the line of sight are slow. The division between drowsiness level 3 or higher and drowsiness level less than 3 can also be rephrased as a division of whether or not the subject needs to be warned. A sleepiness level of 3 or higher is a category that requires a warning to the subject. A drowsiness level of less than 3 is a category in which the subject does not need to be alerted.

Drowsiness level 4 is the degree corresponding to Very Sleepy. The characteristics of drowsiness level 4 include the following. The first is the tilting of the head forward. The second is that the head falls backwards. Sleepiness level 5 is a degree corresponding to sleeping (Sleeping). Drowsiness level 5 can be rephrased as a sleeping state. Drowsiness level 5 is characterized by closing the eyelids for a few seconds.

In this embodiment, the case where the degree of drowsiness is classified into the above six categories will be described as an example, but it is not necessarily limited to this. For example, it may be configured to at least distinguish whether or not the target person needs to be warned. Moreover, it is good also as a structure which distinguishes at least whether a subject is aware of drowsiness, and whether a subject's warning is required.

In this embodiment, a configuration is shown in which the drowsiness of the subject is identified based on the image captured by the indoor camera 30, but this is not necessarily the case. For example, the drowsiness identifying unit 111 may identify the subject's drowsiness based on the biological information measured by a biosensor that measures the subject's biological information. The biosensor may be provided in the vehicle, such as in the steering wheel, seat, or the like. Also, the biosensor may be configured to be provided in a wearable device worn by the subject. If the wearable device is provided with a biosensor, the HCU 10 may acquire the measurement result of the biosensor via short-range wireless communication, for example. Examples of biological information measured by a biological sensor include respiration, pulse, heart rate, skin temperature, and the like.

The slackness specifying unit 112 specifies the slackness of the seat belt worn by the occupant of the vehicle. The slackness identifying unit 112 may identify the slackness of the seat belt using the results detected by the indoor camera 30 . For example, the slackness specifying unit 112 may specify the slackness of the seat belt from the posture detected by the indoor camera 30 and the seat slide position acquired from the seat ECU 20 . As a specific example, if the slackness of the seat belt is greatly specified as the divergence in the longitudinal direction of the own vehicle between the position of the subject's head and the sliding position of the seat on which the subject is seated increases. good. This is because the more the occupant leans forward with respect to the sliding position of the seat, the more likely the seat belt is loosened. The slackness identifying unit 112 may classify the slackness of the seat belt into two stages, i.e., slackness and not slackness. In addition, when the slackness identification unit 112 detects a motion of loosening the seat belt by hand, the slackness degree of the seat belt is determined to be one of two levels: loose and not loose. should be specified. The posture and movement of the occupant may be identified by the occupant-related state identification unit 101 based on the image captured by the indoor camera 30 .

The physique identifying unit 113 identifies the physique of the occupant by recognizing the image captured by the indoor camera 30 . For example, the width of the occupant's torso, the width of the shoulders, etc. may be specified as the physique. The physique identifying unit 113 may be configured to authenticate each passenger by face authentication or the like, and store the physique of each crew member when he/she wears light clothing in the non-volatile memory of the HCU 10 . As for the physique when wearing light clothes, the physique when wearing light clothes for each passenger may be stored by overwriting the physique specified as smaller for the same passenger and leaving it in the non-volatile memory. This is because it is presumed that the smaller the physique is identified, the lighter the occupant is wearing.

The presentation control unit 102 causes the presentation device 40 to present information. As an example, the presentation control unit 102 may cause the presentation device 40 to issue an alarm when the drowsiness level specified by the drowsiness specifying unit 111 is 3 or higher. For example, a warning may be displayed on the display 41 . Alternatively, a warning sound or warning voice may be output from the voice output device 42 .

The optimum determination unit 103 determines the mode of stimulation by retraction of the seat belt (hereinafter referred to as retraction stimulation) according to the occupant-related state identified by the occupant-related state identification unit 101 . It is preferable that the optimum determination unit 103 determines at least one of the intensity and pattern of the attraction stimulation as the aspect of the attraction stimulation according to the degree of drowsiness of the occupant identified by the drowsiness identification unit 111 . In this embodiment, it is assumed that one set of the entrainment stimulus is a plurality of stimuli. The first stimulation within one set is called the starting stimulation. The second and subsequent stimulations within one set are called subsequent stimulations. It is preferable that the initial stimulus has a weaker intensity than the subsequent stimulus. This is to make it less likely that a situation in which the target person is a driver will startle the driver and hinder driving. In the following, an example will be described in which the attraction stimulus is two times and the stimulus is one set. Moreover, the level of intensity of stimulus may be expressed by the length of duration of one stimulus or by the speed of retraction of the seat belt. Alternatively, the intensity of the stimulus may be expressed by the retraction amount of the seat belt.

The optimum determination unit 103 determines the pattern of the attraction stimulus so that the interval between stimulations in one set of the attraction stimulation becomes shorter as the drowsiness level of the occupant identified by the drowsiness identification unit 111 increases. is preferred. This is because the shorter the intervals between a plurality of stimulations in one set, the easier it is for a sense of warning to be conveyed.

Here, using FIG. 3, an example is shown in which the interval between stimulations within one set of attraction stimulations is shortened as the drowsiness level of the occupant increases. The vertical axis of the graph in FIG. 3 indicates the presence or absence of stimulation. Specifically, 0 indicates no stimulation, and 1 indicates the presence of stimulation. The horizontal axis of FIG. 3 indicates time in milliseconds (ms). F in FIG. 3 indicates the starting stimulus. S in FIG. 3 indicates the subsequent stimulation. F+S in FIG. 3 represents one set of stimuli.

As shown in FIG. 3, for example, the interval between stimulations in one set at drowsiness level 3 may be made shorter than that at drowsiness level 2. This is because at drowsiness level 2, the target person feels drowsiness but has not yet reached a level at which a warning is necessary, so the need to issue a warning is lower than at drowsiness level 3. For example, in the case of drowsiness level 2, the stimulation interval in one set should be 500 ms or longer. In the case of drowsiness level 3, the stimulation interval in one set should be 100 ms or more and less than 500 ms. The reason why the interval between stimulations in one set is set to 100 ms or longer is to allow the subject to distinguish and recognize two stimulations in one set. Hereinafter, this pattern for drowsiness level 3 is called pattern A, and this pattern for drowsiness level 2 is called pattern B. In the example of FIG. 3, the duration of the initial stimulus is shorter than the duration of the subsequent stimulus and is weaker in intensity than the subsequent stimulus.

The optimal determination unit 103 determines the pattern of the attraction stimulus so that the frequency of each set of the attraction stimulus increases as the degree of drowsiness of the occupant identified by the drowsiness identification unit 111 increases. is preferred. This is because the higher the frequency of stimulation for each set, the easier it is for a sense of warning to be conveyed.

Here, using FIG. 4, an example is shown in which the frequency of each set of entrainment stimuli is increased as the drowsiness level of the occupant increases. The vertical axis of the graph in FIG. 4 indicates the presence or absence of stimulation. Specifically, 0 indicates no stimulation, and 1 indicates the presence of stimulation. The horizontal axis of FIG. 4 indicates time in seconds (s). F+S in FIG. 4 represents one set of stimuli.

As shown in FIG. 4, for example, the frequency of stimulation for each set at sleepiness level 3 may be set higher than that at sleepiness level 2. This is because in the case of drowsiness level 2, it is less necessary to give a warning than in the case of drowsiness level 3, and it is preferable to give priority to suppressing annoyance. As an example, in the case of drowsiness level 2, as pattern B, the frequency of stimulation for each set may be one set per 1000 to 120 seconds. In the case of drowsiness level 3, as pattern A, the frequency of stimulation for each set should be one set for 80 to 100 seconds.

It is preferable that the optimum determination unit 103 determines a higher strength of the pulling stimulus for the seat belt as the looseness of the seat belt specified by the looseness specifying unit 112 increases. This is because the greater the slackness of the seat belt, the more difficult it is for the pulling stimulus to be transmitted to the subject. As an example, the optimum determination unit 103 may determine a target retraction amount of the seat belt (hereinafter referred to as a target retraction amount) as the strength of the retraction stimulus. The optimum determination unit 103 may specify an index (hereinafter referred to as intensity level) divided into a plurality of stages as the intensity of the attraction stimulus.

If the optimum determination unit 103 determines that the physique of the occupant identified by the physique identification unit 113 is larger than the physique of the occupant in the past when the occupant was lightly dressed (hereinafter referred to as the reference physique), It is preferable to determine the strength of the pull-in stimulus for the seat belt worn by the occupant higher than in the case where it is not determined that the occupant is larger than the reference physique of the occupant. This is because if the clothing is thick, the attraction stimulus is less likely to be transmitted to the subject. As for the reference physique, the physique of each crew member when lightly dressed, which was previously stored in the non-volatile memory by the physique identifying unit 113, may be used. If the physique at the time of thin clothing is not stored in the non-volatile memory, the processing according to whether or not it is determined that the physique is larger than the reference physique may be omitted.

When the physique of the occupant identified by the physique identification unit 113 is equal to or greater than a specified value, the optimal determination unit 103 determines that the attraction stimulus for the seatbelt worn by the occupant is greater than when the physique of the occupant is less than the specified value. It is preferable to determine the strength to be high. This is because there is a high possibility that the pull-in stimulus is less likely to be transmitted to a passenger with a large physique. As for the specified value, the value of the average physique of an ordinary person may be used. The prescribed value may be different depending on gender.

It should be noted that, if a plurality of conditions for determining the intensity of the entrainment stimulus to be high are satisfied, the optimum determination unit 103 may increase the target entrainment amount and intensity level by the amount that satisfies the conditions. Further, the optimum determination unit 103 may be configured to increase the strength of the attraction stimulus as the drowsiness level of the passenger identified by the drowsiness identification unit 111 increases.

The retraction control unit 104 causes the seatbelt actuator 50 to feed and retract the seatbelt of the vehicle. The processing in this pull-in control unit 104 corresponds to the pull-in control step. The pull-in control unit 104 causes the pull-in stimulus to be performed by winding up the seat belt. As for the retraction stimulus, one stimulus may be performed after the seat belt is retracted until the seat belt is returned to the retraction amount before retraction.

Based on the fact that the degree of drowsiness of the occupant identified by the drowsiness identification unit 111 is greater than or equal to the first threshold, the pull-in control unit 104 may cause the occupant to pull in the seat belt worn by the occupant. The first threshold is a value that can be set arbitrarily. It is preferable that the first threshold be a value lower than the value that determines whether or not the subject needs to be warned. In the following description, it is assumed that the first threshold is level 2 of drowsiness. According to this, when the occupant's drowsiness level is such that a warning is not necessary, by maintaining wakefulness only with the withdrawal stimulus, it is possible to reduce the annoyance of maintaining wakefulness due to the warning from the presentation device 40. be possible.

The entrainment control unit 104 performs entrainment stimulation according to the pattern and/or intensity determined by the optimum determination unit 103 . If the optimum determination unit 103 determines only one of the pattern and the intensity, the attraction control unit 104 causes the attraction stimulation to be performed according to the determined one. When both the pattern and the intensity are determined by the optimum determination unit 103, the attraction control unit 104 causes the attraction stimulation to be performed according to the determined pattern and intensity. That is, the attraction-in control unit 104 changes the mode of the attraction-in stimulation according to the occupant-related state specified by the occupant-related state specifying unit 101 . When the target retraction amount is determined as the strength by the optimum determining unit 103, the actually required retraction amount is specified from the retraction amount of the seat belt detected by the seat belt sensor 60 and the target retraction amount. It should be stimulating. When the intensity level is determined as the intensity by the optimum determining unit 103, the target attraction amount is calculated so as to increase as the intensity level increases, and the attraction stimulation is performed in the same manner as described above. Let it be.

If the optimal determination unit 103 determines at least one of the intensity and pattern of the attraction stimulus according to the degree of drowsiness of the passenger identified by the drowsiness identification unit 111, the following may be done. The drawing-in control unit 104 changes at least one of the strength and pattern of the drawing-in stimulus according to the drowsiness level of the occupant identified by the drowsiness identification unit 111 . The entrainment control unit 104 may shorten the interval between the entrainment stimuli within one set as the drowsiness level of the occupant identified by the drowsiness identification unit 111 increases. The drawing-in control unit 104 may increase the frequency of each set of the drawing-in stimulus as the drowsiness level of the occupant identified by the drowsiness identification unit 111 increases. The entrainment control unit 104 may make the initial stimulus in one set of the entrainment stimulus weaker in intensity than the subsequent stimulus.

When the optimal determination unit 103 determines the strength of the pulling stimulus for the seat belt to be increased as the degree of slackness of the seat belt specified by the slackness determination unit 112 increases, the following may be performed. . The pull-in control unit 104 may increase the strength of the pull-in stimulus for the seat belt as the looseness of the seat belt specified by the looseness specifying unit 112 increases.

When the optimum determination unit 103 determines that the physique of the occupant identified by the physique identification unit 113 is larger than the reference physique of the occupant and determines the strength of the attraction stimulus to be high, the following may be performed. . When the pull-in control unit 104 determines that the physique of the occupant identified by the physique identification unit 113 is larger than the reference physique of the occupant, the drawing-in control unit 104 determines that the occupant is larger than the reference physique of the occupant. It is sufficient to increase the strength of the retraction stimulus for the seat belt worn by the occupant.

If the physique of the occupant identified by the physique identification section 113 is equal to or greater than the specified value and the strength of the entrainment stimulus is determined to be high by the optimum determination section 103, the following may be performed. When the physique of the occupant identified by the physique identification unit 113 is equal to or greater than a prescribed value, the attraction control unit 104 controls the attraction stimulation for the seat belt worn by the occupant as compared to when the physique of the occupant is less than the prescribed value. Strength should be increased.

It is preferable that the pull-in control unit 104 does not perform the pull-in stimulation when the occupant's face direction detected by the indoor camera 30 is tilted to the left or right. This is because when the driver's face is tilted to the left or right, there is a high possibility that the driver will be hindered from driving. It is preferable to limit this attraction stimulus only when the passenger is the driver. When the occupant's face orientation detected by the indoor camera 30 returns to the front, the withdrawal control unit 104 may cause the temporarily stopped withdrawal stimulation to be performed. Whether the face is oriented to the left or right or to the front may be determined using a determination threshold value for distinguishing between them.

<Arousal maintenance related processing in HCU 10>
Next, an example of the flow of wakefulness maintenance-related processing in the HCU 10 will be described using the flowchart of FIG. The flowchart of FIG. 5 may be configured to start when, for example, a switch (hereinafter referred to as a power switch) for starting the internal combustion engine or motor generator of the vehicle is turned on. In addition, in the case of a configuration in which the on/off setting of the function to execute the process related to maintaining wakefulness can be switched via the operation device, the function to execute the process related to maintaining wakefulness must be turned on. The configuration may be added.

First, in step S1, the drowsiness identification unit 111 identifies the drowsiness level of the driver. In step S2, if the drowsiness level is 2 or higher (YES in S2), the process proceeds to step S3. On the other hand, when the drowsiness level is less than 2, the process proceeds to step S12. In step S3, if the drowsiness level is 3 or higher (YES in S3), the process proceeds to step S4. On the other hand, when the drowsiness level is 2, the process moves to step S5.

In step S4, the optimum determination unit 103 determines the pattern of the entrainment stimulation according to the drowsiness level specified in S1, and proceeds to step S6. In S4 where the drowsiness level is 3 or higher, pattern A may be determined. In step S5, the optimum determination unit 103 determines the pattern of the entrainment stimulation according to the drowsiness level specified in S1, and the process proceeds to step S6. In S5 where the drowsiness level is 2, pattern B may be determined.

In step S6, the slackness identifying unit 112 identifies the slackness of the seat belt worn by the driver. If the seat belt is loose (YES in S6), the process proceeds to step S9. On the other hand, if the seat belt is not loosened (NO in S6), the process proceeds to step S7. For example, if the degree of slackness specified by the degree-of-slackness specifying unit 112 is only two categories of looseness and not-looseness, the following may be done. If it is specified by the looseness specifying unit 112 that it is loose, it is determined that it is loose, and if it is specified that it is not loose, it is determined that it is not loose. If the degree of slackness specified by the slackness specifying unit 112 is three or more categories, the following may be performed. If the degree of slackness identified by the degree of slackness identification unit 112 is equal to or greater than a certain value, it is assumed that the joint is loose, and if the degree of slackness is less than the certain value, it is judged that the joint is not loose. The constant value referred to here may be set arbitrarily.

In step S7, the physique identifying unit 113 identifies the physique of the driver. If the specified driver's physique is larger than the driver's standard physique and is thickly dressed (YES in S7), the process proceeds to step S9. On the other hand, if the driver is not thickly dressed (NO in S7), the process proceeds to step S8.

In step S8, if the physique of the driver identified by the physique identification unit 113 is greater than or equal to the specified value (YES in S8), the process proceeds to step S9. On the other hand, if the physique of the driver is less than the specified value (NO in S8), the process proceeds to step S10. In step S9, the optimum determination unit 103 determines the strength of the attraction stimulus to be higher than the default strength.

In step S10, the attraction control unit 104 determines whether or not the attraction stimulation is possible. As an example, when the face direction of the driver detected by the indoor camera 30 is tilted to the left or right, it may be determined that the entrainment stimulus is impossible. On the other hand, if the driver faces the front, it may be determined that the attraction stimulus is possible. In S10, when it is determined that the attraction stimulus is possible (YES in S10), the process proceeds to step S11. On the other hand, when it is determined that the attraction stimulus is impossible (NO in S10), the process proceeds to step S12.

In step S11, the pull-in control unit 104 causes the seat belt worn by the driver to pull in. In S11, the entrainment stimulation is performed according to the pattern determined in S4 or S5. Also, in S11, if the process of S9 has been performed, the entrainment stimulation is performed with the intensity determined in S9. In S11, if the process of S9 has not been performed, the entrainment stimulation may be performed with the default intensity.

In step S12, if it is time to end the wakefulness maintenance related process (YES in S12), the wakefulness maintenance related process ends. On the other hand, if it is not the end timing of the wakefulness maintenance related process (NO in S12), the process returns to S1 and repeats the process. An example of the termination timing of the wakefulness maintenance related process is that the power switch of the host vehicle is turned off, or that the function of executing the wakefulness maintenance related process is switched off.

Although the flowchart in FIG. 5 shows an example in which the degree of increasing the intensity of the attraction stimulus is uniform regardless of how many conditions for increasing the intensity of the attraction stimulus are satisfied, this is not necessarily the case. For example, the degree of increasing the intensity of the attraction stimulus may be increased as the number of conditions satisfying the condition for increasing the intensity of the attraction stimulus increases.

<Summary of Embodiment 1>
According to the configuration of the first embodiment, based on the fact that the drowsiness level of the driver is equal to or higher than a predetermined threshold, the pulling stimulus, which is a stimulus caused by the pulling of the seat belt worn by the driver, is performed. Awakening can be maintained. In addition, since the pattern and intensity of the attraction stimulus are changed according to the drowsiness level of the driver, the looseness of the seat belt worn by the driver, and the physique of the driver, the pattern and intensity of the attraction stimulus can be changed regardless of these conditions. It is possible to provide a more appropriate stimulus for the driver as compared with the case where the is not changed. As a result, it is possible to make the stimulus for maintaining wakefulness by retracting the seat belt more suitable for the subject.

(Embodiment 2)
In the first embodiment, the configuration is shown in which the target of the attraction stimulus is only the driver, but this is not necessarily the case. For example, a configuration may be adopted in which the target persons of the attraction stimulus are the driver and the fellow passenger (hereinafter referred to as Embodiment 2). An example of the second embodiment will be described below with reference to the drawings. The wakefulness-maintaining system 1 of Embodiment 2 is the same as the wakefulness-maintaining system 1 of Embodiment 1 except that it includes an HCU 10a instead of the HCU 10. FIG.

First, the schematic configuration of the HCU 10a will be described using FIG. As shown in FIG. 6, the HCU 10a includes, as functional blocks, an occupant-related state identification unit 101a, a presentation control unit 102a, an optimum determination unit 103a, and a retraction control unit 104a. This HCU 10a also corresponds to a wakefulness maintenance device. Execution of the process of each functional block of the HCU 10a by the computer corresponds to execution of the wakefulness maintaining method.

The occupant-related state identification unit 101a is the same as the occupant-related state identification unit 101 of Embodiment 1, except that it also identifies, as occupant-related states, states related to fellow passengers in the vehicle in addition to the driver. The processing in the occupant-related state identification section 101a also corresponds to the occupant-related state identification step. The occupant-related state identification unit 101a has a drowsiness identification unit 111a, a slackness identification unit 112, and a physique identification unit 113 as sub-functional blocks. The occupant-related state identification unit 101a is the same as the occupant-related state identification unit 101 of the first embodiment except that the drowsiness identification unit 111a is replaced with the drowsiness identification unit 111a.

The occupant-related state identifying unit 101a preferably also identifies the posture of the fellow passenger or the reclining state of the seat. The posture of the fellow passenger may be the inclination of the upper body of the fellow passenger with respect to the longitudinal direction of the vehicle. The posture of the fellow passenger may be specified by recognizing the image captured by the indoor camera 30 . The reclining state of the passenger's seat may be identified from the reclining position obtained from the seat ECU 20 .

The drowsiness identification unit 111a is the same as the drowsiness identification unit 111 of the first embodiment, except that it also identifies the drowsiness level, which is the degree of drowsiness of the passenger in the vehicle. The drowsiness level of the fellow passenger may also be identified in the same manner as the drowsiness level of the driver. In the second embodiment, it is assumed that the indoor camera 30 captures not only the driver's seat but also the passenger's seat such as the passenger's seat and the rear seat.

The presentation control unit 102a is the same as the presentation control unit 102 of the first embodiment, except that it presents information for fellow passengers (hereinafter referred to as information for fellow passengers) that notifies that the drowsiness level of the driver is high. . For example, the presentation control unit 102a may cause the presentation device 40 to present information for fellow passengers when the drowsiness level of the driver identified by the drowsiness identification unit 111a is 3 or higher. The presentation device 40 for presenting information for fellow passengers includes a CID as a display device 41 and a speaker as an audio output device 42 .

The optimum determining unit 103a is identical to the optimum determining unit 103 of the first embodiment, except that the mode of the attraction stimulus is determined according to the occupant-related state specified by the occupant-related state specifying unit 101a for the fellow passenger of the own vehicle. It is the same. Determination of the mode of attraction stimulus for the fellow passenger by the optimum determination unit 103a will be described below.

If the passenger's drowsiness level identified by the drowsiness identification unit 111a is 1 or more and is in a non-awakened state, the optimum determination unit 103a determines that the pattern of the entrainment stimulation is a pattern in which a plurality of stimulations constitutes one set. good. Also, the initial stimulus may be determined to be weaker in intensity than the subsequent stimulus. As an example, the pattern B described in the first embodiment may be determined. On the other hand, when the passenger's drowsiness level specified by the drowsiness specifying unit 111a is 0 and is in an awake state, the pattern of the attraction stimulus may be determined as a pattern in which one stimulus is one set. This pattern will be referred to as pattern C hereinafter. The intensity of the entraining stimulus may be the same weak stimulus as the starting stimulus when multiple stimuli are set as one set pattern. According to this, when the fellow passenger is in an awake state, the number of stimuli in one set is reduced and the stimuli are also weakened, making it possible to make the stimuli less annoying. On the other hand, when the fellow passenger is in a non-awakened state, by increasing the number of stimulations in one set and strengthening the stimulation, it is possible to invite the passenger into an awakened state.

The pull-in control unit 104a is the same as the pull-in control unit 104 of the first embodiment, except that the seat belt actuator 50 also causes the seat belt to be fed out and retracted for the passenger. The processing in the pull-in control unit 104a also corresponds to the pull-in control step. The attraction stimulus for the fellow passenger in the attraction control unit 104a will be described below.

When the driver's drowsiness specified by the drowsiness specifying unit 111a is less than the second threshold, the pull-in control unit 104a preferably does not perform the pull-in stimulation for the seat belt worn by the fellow passenger. It is preferable that the pull-in control unit 104a performs a pull-in stimulation for the seat belt worn by the fellow passenger based on whether the drowsiness of the driver identified by the drowsiness identification unit 111a is equal to or greater than the second threshold. The second threshold is a value that can be set arbitrarily. The second threshold is preferably a value that determines whether or not a warning is required for the driver. In the following description, it is assumed that the second threshold is drowsiness level 3. FIG. According to this, when the drowsiness level of the driver is such that an alarm is necessary, and if the driver's stimulus alone cannot keep the driver awake, the stimulus also attracts the passenger. By doing so, it is possible to keep the driver awake with the cooperation of the fellow passengers.

The attraction control unit 104a causes the attraction stimulation to be performed according to the stimulation mode determined by the optimum determination unit 103a when performing the attraction stimulation for the fellow passenger. If the sleepiness level of the fellow passenger identified by the sleepiness identification unit 111a corresponds to the non-awakened state, the pull-in control unit 104a may perform the following. The entrainment control unit 104a may perform a set of entrainment stimulations consisting of a plurality of stimulations, and make the first stimulation in one set have a weaker intensity than the subsequent stimulations. On the other hand, if the fellow passenger's drowsiness level identified by the drowsiness identification unit 111a corresponds to the wakeful state, the drawing-in control unit 104a may perform the following. The entrainment control unit 104a performs entrainment stimulation with one stimulation set as one set, and sets the intensity of the stimulation to that of the first stimulation in one set when the fellow passenger's drowsiness level corresponds to the non-awakened state. It should be strength.

Even if the drowsiness of the driver identified by the drowsiness identification unit 111a is equal to or greater than the second threshold value, the pull-in control unit 104a determines whether the posture of the fellow passenger identified by the occupant-related state identification unit 101a or the reclining state of the seat is When the effect of the pulling stimulus is estimated to be low, it is preferable not to perform the pulling stimulus for the seat belt worn by the fellow passenger. This is because when the seat back of the seat on which the fellow passenger sits is lying on the floor side for a certain amount or more, there is a high possibility that the retraction stimulus will not be transmitted to the subject even if the seat belt is retracted. The state in which the entrainment stimulus effect is estimated to be low may be determined in advance by experiments, simulations, or the like.

Further, as described above, even when the retraction control unit 104a does not perform the retraction stimulus for the seat belt worn by the fellow passenger, if the degree of urgency is high, the seating of the fellow passenger It is also possible to forcibly raise the sheet to be pulled and then perform the drawing stimulation. This configuration may be used only when an electric seat capable of electrically switching the reclining position is employed. According to the above configuration, even if the passenger's posture or the reclining state of the seat is a state in which the effect of the attraction stimulus is estimated to be low, the effect of the attraction stimulus is increased when the degree of urgency is high. becomes possible. A case of high urgency includes a case where the driver's drowsiness level does not improve for a certain period of time or longer, a case where the driver's drowsiness is getting worse, and the like.

When presenting fellow-passenger-oriented information, the presentation control unit 102a preferably causes the fellow-passenger-oriented information to be presented after the attraction control unit 104a performs the attraction-in stimulus for the fellow-passenger described above. This is because the presentation of information from the presentation device 40 of the vehicle is mainly directed to the driver, and therefore the information for the fellow passenger cannot be conveyed to the fellow passenger only by performing the information for the fellow passenger from the presentation device 40 alone. This is because it is highly unlikely that By presenting the information for the fellow passenger after the attraction stimulus for the fellow passenger is performed, the information for the fellow passenger can be easily conveyed to the fellow passenger.

<Arousal Maintenance Related Processing in HCU 10a>
Here, an example of the flow of wakefulness maintenance-related processing for a fellow passenger in the HCU 10a will be described using the flowchart of FIG. The flow of wakefulness maintenance related processing for the driver in the HCU 10a may be the same as that shown in the flowchart of FIG. 5 of the first embodiment. The flowchart of FIG. 7 may be configured to start when the presence of a fellow passenger is confirmed in the own vehicle. In the HCU 10a, if the occupant-related state identifying unit 101a can identify the states of the occupants other than the driver, the presence of the fellow passenger may be confirmed. It should be noted that in the case of a configuration in which the on/off setting of the function for executing the process related to maintaining wakefulness can be switched via the operation device, the fact that the function for executing the process related to maintaining wakefulness is turned on also means that the process shown in FIG. It may be configured to be added to the start condition of the flow chart.

First, in step S21, the drowsiness identification unit 111a identifies the drowsiness level of the driver. In step S22, if the drowsiness level of the driver is equal to or higher than the second threshold (YES in S22), the process proceeds to step S23. On the other hand, if the drowsiness level of the driver is less than the second threshold, the process proceeds to step S32. For example, sleepiness level 3 is set as the second threshold.

In step S23, if the passenger's posture or seat reclining state specified by the occupant-related state specifying unit 101a is in a state in which it is estimated that the effect of the entrainment stimulus is low (i.e., not subject to stimulus) (YES in S23) ), the process moves to step S24. On the other hand, if the effect of the attraction stimulus is not estimated to be low (NO in S23), the process proceeds to step S26. Whether or not the passenger's posture or seat reclining state identified by the occupant-related state identification unit 101a is a state in which the effect of the attraction stimulus is estimated to be low may be determined by the withdrawal control unit 104a.

In step S24, if the degree of urgency is high (YES in S24), go to step S25. On the other hand, if the degree of urgency is not high (NO in S24), the process proceeds to step S32. Whether or not the degree of urgency is high may be determined by the pull-in control unit 104a. In step S25, the HCU 10a instructs the seat ECU 20 to raise the seat back of the electric seat on which the fellow passenger sits, and the process proceeds to step S26. The reclining position at which the seatback is raised may be a position corresponding to a state in which it is estimated that the pulling stimulus is highly effective.

In step S26, the drowsiness identification unit 111a identifies the fellow passenger's drowsiness level. In step S27, if the passenger's sleepiness level is 0 (YES in S27), the process proceeds to step S28. On the other hand, if the fellow passenger's drowsiness level is 1 or more and is in a non-awakened state, the process proceeds to step S29.

In step S28, the optimum determination unit 103a determines a pattern in which one stimulus is one set as the pattern of the attraction stimulus, and the process proceeds to step S30. As an example, the pattern C described above may be determined. In step S29, the optimum determination unit 103a determines a pattern in which a plurality of stimuli constitutes one set as the pattern of the attraction stimulus, and the process proceeds to step S30. As an example, the pattern B described above may be determined.

In step S30, the pull-in control unit 104a causes the seat belt worn by the fellow passenger to pull in. At S30, a drawing stimulus is performed according to the pattern determined at S28 or S29. In step S31, the presentation control unit 102a causes the presentation device 40 to present information for fellow passengers.

In step S32, if it is time to end the wakefulness maintenance related process (YES in S32), the wakefulness maintenance related process ends. On the other hand, if it is not the end timing of the wakefulness maintenance related process (NO in S32), the process returns to S21 and repeats the process. An example of the termination timing of the wakefulness maintenance related process is that the power switch of the host vehicle is turned off, or that the function of executing the wakefulness maintenance related process is switched off.

In the flowchart of FIG. 7, the processing of S23 to S25 may be configured to be performed between the processing of S28, S29 and S30. Further, in the flowchart of FIG. 7, if the seat on which the fellow passenger is seated is not an electric seat, the processing of S24 to S25 may be omitted, and if YES in S23, the process may proceed to S32. In this case, the presentation control unit 102a may present the information for the fellow passenger without performing the pull-in stimulation of the seat belt worn by the fellow passenger. Further, in the case of NO in S24, the presentation control unit 102a may present the information for the fellow passenger without performing the pull-in stimulation of the seat belt worn by the fellow passenger.

It should be noted that in the flowchart of FIG. 7, the following may be performed once the process of presenting the information for the fellow passenger after performing the pull-in stimulation of the seat belt worn by the fellow passenger. For example, until the drowsiness level of the driver becomes less than the second threshold, the information for the fellow passenger may be presented, but the pull-in stimulation of the seat belt worn by the fellow passenger may not be performed. According to this, it is possible to reduce the annoyance of a fellow passenger who notices the fellow-passenger-oriented information by the attracting-in stimulus, and to receive the fellow-passenger-oriented information even after the fellow-passenger has noticed the fellow-passenger-oriented information.

In addition, the attraction control unit 104a notifies the fellow passenger that the drowsiness level of the driver does not fall below the second threshold value within a certain period of time after the stimulation, even though the driver is caused to perform the attraction stimulation. It may be a condition for stimulating. The fixed period referred to here may be set arbitrarily. According to this, even when the drowsiness level of the driver improves to less than the second threshold value due to the attraction stimulus, it is possible to reduce the troublesomeness and waste of having the fellow passenger perform the attraction stimulus.

According to the configuration of the second embodiment, when the driver becomes accustomed to the entrainment stimulus and it becomes difficult to improve the drowsiness level with the entrainment stimulus, the drowsiness level wakes up even with the cooperation of the passenger. In the case of the degree of power, it is possible to provide the passenger with an entrainment stimulus to obtain the cooperation of the passenger in improving the drowsiness of the driver.

In the second embodiment, the slackness specifying unit 112 and the physique specifying unit 113 do not specify the slackness of the seat belt and the physique of the fellow passenger, but this is not necessarily the case. For example, the slackness specifying unit 112 and the physique specifying unit 113 may also be configured to specify the slackness of the seat belt and the physique of the fellow passenger. In this case, the optimum determining unit 103a may determine the strength of the attraction stimulus for the fellow passenger according to the slackness of the seat belt and the physique of the fellow passenger, similarly to the optimum deciding unit 103 of the first embodiment. . Then, the pull-in control unit 104a may change the strength of the pull-in stimulus for the fellow passenger according to the slackness of the seat belt and the physique of the fellow passenger.

(Embodiment 3)
In the above-described embodiment, the configuration for identifying the looseness of the seat belt using the result detected by the indoor camera 30 is shown, but the configuration is not necessarily limited to this. For example, the configuration of Embodiment 3 below may be used. An example of the third embodiment will be described below with reference to the drawings.

The wakefulness maintenance system 1b of Embodiment 3 is used in a vehicle. The wakefulness maintenance system 1b includes an HCU 10b, a seat ECU 20, an indoor camera 30, a presentation device 40, a seatbelt actuator 50, a seatbelt sensor 60, and a pressure sensor 70, as shown in FIG. The wakefulness-maintaining system 1b is similar to the wakefulness-maintaining system 1 of Embodiment 1 except that it includes an HCU 10b instead of the HCU 10 and that it includes a pressure sensor .

The pressure sensor 70 is provided on the side of the seat belt that contacts the occupant when the seat belt is worn. As a result, the pressure sensor 70 outputs a pressure value corresponding to the looseness of the seat belt when the occupant wears the seat belt. The pressure-sensitive sensor 70 is provided on the seat belt of the seat on which the occupant who is the object of the pulling stimulus sits. The pressure value detected by the pressure sensor 70 may be output to the HCU 10b.

As shown in FIG. 9, the HCU 10b includes an occupant-related state identification unit 101b, a presentation control unit 102, an optimum determination unit 103b, and a pull-in control unit 104 as functional blocks. The HCU 10b is the same as the HCU 10 of the first embodiment, except that it includes an occupant-related state identification unit 101b and an optimum determination unit 103b instead of the occupant-related state identification unit 101 and the optimum determination unit 103. This HCU 10b also corresponds to a wakefulness maintenance device. Execution of the process of each functional block of the HCU 10b by the computer corresponds to execution of the wakefulness maintaining method.

The occupant-related state identification unit 101b is the same as the occupant-related state identification unit 101 of the first embodiment, except that some processing is different. The processing in the occupant-related state identification section 101b also corresponds to the occupant-related state identification step. The occupant-related state identification unit 101b has a drowsiness identification unit 111 and a slackness identification unit 112b as sub-functional blocks. The occupant-related condition identification unit 101b has the occupant-related condition identification unit 101b of the first embodiment, except that it has a slackness identification unit 112a instead of the slackness identification unit 112 and that it does not have the physique identification unit 113. It is similar to the state identification unit 101 .

The slackness specifying unit 112b uses the result detected by the pressure sensor 70 to specify the slackness of the seat belt. Based on the pressure value detected by the pressure sensor 70, the slackness specifying unit 112b utilizes the relationship that the pressure value detected by the pressure sensor 70 decreases as the slackness of the seat belt increases. , the slackness of the seat belt should be specified. The degree of slackness of the seat belt may be specified by classifying it into three or more levels, or by classifying it into two levels, that is, looseness and not slackness. In the case of classifying into two stages of loosening and not loosening and specifying, it is possible to classify and specify whether the pressure value is equal to or less than the threshold value for this class.

The optimal determination unit 103b uses the slackness specified by the slackness specifying unit 112b instead of the slackness specified by the slackness specifying unit 112, and does not use the physique of the occupant specified by the physique specifying unit 113. Except for this, it is the same as the optimum determining unit 103 of the first embodiment. The optimum determining unit 103b determines a higher strength of the pulling stimulus for the seat belt as the degree of slackness of the seat belt specified by the slackness specifying unit 112b increases.

Note that the configuration of the third embodiment and the configuration of the second embodiment may be combined. Even with the configuration of the third embodiment, the strength of the retraction stimulus is changed according to the degree of looseness of the seat belt worn by the occupant. , it becomes possible to make it a more appropriate stimulus for the occupant.

(Embodiment 4)
Further, as a configuration for specifying the looseness of the seat belt, for example, the configuration of the following embodiment 4 may be used. An example of the fourth embodiment will be described below with reference to the drawings. The wakefulness-maintaining system 1 of Embodiment 4 is the same as the wakefulness-maintaining system 1 of Embodiment 1 except that it includes an HCU 10c instead of the HCU 10. FIG.

Here, the schematic configuration of the HCU 10c will be explained using FIG. As shown in FIG. 10, the HCU 10c includes an occupant-related state identification unit 101c, a presentation control unit 102, an optimum determination unit 103c, a pull-in control unit 104, and a current monitor unit 105 as functional blocks. The HCU 10c is similar to that of the first embodiment, except that it includes an occupant-related state identification unit 101c and an optimum determination unit 103c instead of the occupant-related state identification unit 101 and the optimum determination unit 103, and a current monitor unit 105. It is the same as HCU10. This HCU 10c also corresponds to a wakefulness maintenance device. Execution of the process of each functional block of the HCU 10c by the computer corresponds to execution of the wakefulness maintaining method.

The current monitor unit 105 acquires the motor current value of the seatbelt actuator 50 . The occupant-related state identification unit 101c is the same as the occupant-related state identification unit 101 of the first embodiment, except that some processing is different. The processing in the occupant-related state identification unit 101c also corresponds to the occupant-related state identification step. The occupant-related state identification unit 101c has a drowsiness identification unit 111 and a slackness identification unit 112c as sub-functional blocks. The occupant-related state identification unit 101c has the occupant-related state identification unit 101c of the first embodiment, except that it has the slackness identification unit 112c instead of the slackness identification unit 112 and that it does not have the physique identification unit 113. It is similar to the state identification unit 101 .

The looseness specifying unit 112c uses the motor current value acquired by the current monitor unit 105 to specify the looseness of the seat belt. The slackness specifying unit 112c uses the relationship that the motor current value acquired by the current monitor unit 105 decreases as the slackness of the seat belt increases. From the value, the slackness of the seat belt can be identified. For example, when the drowsiness of the driver is greater than or equal to the first threshold, the looseness specifying unit 112c periodically energizes the seatbelt actuator 50 to wind the seatbelt, and adjusts the motor current value of the seatbelt actuator 50 to You should get it. After the motor current value is acquired, the seat belt actuator 50 may return the seat belt retraction amount to the amount before the motor current value was acquired.

Here, using FIG. 11, an example of the motor current value corresponding to the looseness of the seat belt is shown. LL in FIG. 11 indicates an example in which the degree of looseness of the seat belt is large. SL in FIG. 11 indicates an example in which the looseness of the seat belt is small. Let t(s) in FIG. 11 be the masking time required to identify the degree of looseness. M(A) in FIG. 11 is the threshold value of the motor current. The energization of the seatbelt actuator 50 may be continued until the motor current exceeds the threshold value M(A) after the masking time t(s) has elapsed. This should prevent the seat belt from being wound too much. As shown in FIG. 11, when the seat belt actuator 50 is energized, the motor current value of the seat belt actuator 50 is output at a lower value as the degree of looseness of the seat belt increases.

The slackness of the seat belt specified by the slackness specifying unit 112c may be specified by classifying it into three or more stages, or it may be specified by classifying it into two stages, i.e., loose and not loose. good. In the case of classifying into two stages of loosening and not loosening and specifying, it is possible to classify and specify whether the pressure value is equal to or less than the threshold value for this class.

Optimal determination section 103b uses the degree of slackness identified by slackness identification section 112c instead of the degree of slackness identified by slackness identification section 112, and does not use the physique of the occupant identified by physique identification section 113. Except for this, it is the same as the optimum determining unit 103 of the first embodiment. The optimum determining unit 103c determines a higher strength of the pulling stimulus for the seat belt as the degree of slackness of the seat belt specified by the slackness specifying unit 112c increases.

Note that the configuration of the fourth embodiment and the configuration of the second embodiment may be combined. Even with the configuration of Embodiment 4, the strength of the retraction stimulus is changed according to the degree of looseness of the seat belt worn by the occupant. , it becomes possible to make it a more appropriate stimulus for the occupant.

(Embodiment 5)
In the above-described embodiment, a configuration was shown in which the mode of attraction stimulus is changed according to the looseness specified by the looseness specifying units 112, 112a, 112b, and 112c and the physique specified by the physique specifying unit 113, but this is not necessarily the case. is not limited to For example, a configuration may be adopted in which the mode of the attraction stimulus is not changed according to the slackness specified by the slackness specifying units 112 , 112 a , 112 b , and 112 c and the physique specified by the physique specifying unit 113 .

(Embodiment 6)
In the above-described embodiment, the HCUs 10, 10a, 10b, and 10c are responsible for the wakefulness maintenance related process, but this is not necessarily the case. For example, the HCUs 10, 10a, 10b, and 10c and another ECU may be responsible for the wakefulness maintenance related process, or the other ECU may be responsible for the wakefulness maintenance related process.

(Embodiment 7)
Although the wakefulness maintenance systems 1 and 1b are used in automobiles in the above-described embodiments, the configuration is not necessarily limited to this. The wakefulness maintenance systems 1 and 1b can be used in various moving bodies as long as they use seat belts.

It should be noted that the present disclosure is not limited to the above-described embodiments, and can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. Embodiments are also included in the technical scope of the present disclosure. The controller and techniques described in this disclosure may also be implemented by a special purpose computer comprising a processor programmed to perform one or more functions embodied by a computer program. Alternatively, the apparatus and techniques described in this disclosure may be implemented by dedicated hardware logic circuitry. Alternatively, the apparatus and techniques described in this disclosure may be implemented by one or more special purpose computers configured in combination with a processor executing a computer program and one or more hardware logic circuits. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium.

Claims (12)

1. A wakefulness maintenance device that can be used in a vehicle,
   an occupant-related state identifying unit (101, 101a, 101b, 101c) that identifies an occupant-related state, which is a state related to the occupant, including at least the degree of drowsiness of the occupant of the vehicle;
   Based on the fact that the degree of drowsiness of the occupant specified by the occupant-related state specifying unit is equal to or greater than a first threshold, a retraction control unit that performs a retraction stimulus, which is a stimulus caused by retraction of the seat belt worn by the occupant. (104, 104a);
   The wakefulness maintenance device, wherein the withdrawal control section changes the mode of the withdrawal stimulus in accordance with the occupant-related state specified by the occupant-related state specifying section.
2. The wakefulness maintenance device according to claim 1,
   The wake-up control unit changes at least one of the intensity and pattern of the pull-in stimulus as the mode of the pull-in stimulus according to the degree of drowsiness of the occupant specified by the occupant-related state specifying unit.
3. The wakefulness maintenance device according to claim 2,
   The pull-in control unit causes the pull-in stimulation to be performed a plurality of times as one set. 3. A device for maintaining wakefulness, in which stimulation intervals are shortened in one set of the withdrawal stimulations, wherein one set consists of a plurality of stimulations.
4. The wakefulness maintenance device according to claim 2 or 3,
   The pull-in control unit causes the pull-in stimulation to be performed a plurality of times as one set. 3. A device for maintaining wakefulness, which increases the frequency of stimulation for each set of the attraction stimulations, each set consisting of a plurality of stimulations.
5. The wakefulness maintenance device according to any one of claims 2 to 4,
   The attraction control unit performs the attraction stimulation as one set of a plurality of stimulations, and the first stimulation in one set of the attraction stimulation, which is a set of the plurality of stimulations, is performed more than the subsequent stimulations. An arousal maintenance device that makes the intensity weaker.
6. The wakefulness maintenance device according to any one of claims 1 to 5,
   The occupant-related state identification unit identifies the occupant-related state including at least the looseness of the seat belt worn by the occupant in addition to the degree of drowsiness of the occupant of the vehicle,
   The pull-in control unit increases the strength of the pull-in stimulus for the seat belt as a mode of the pull-in stimulus in response to an increase in the looseness of the seat belt specified by the occupant-related state specifying unit. maintenance device.
7. The wakefulness maintenance device according to claim 6,
   The occupant-related state identification unit (101, 101a) identifies the physique of the occupant as the occupant-related state by recognizing the captured image of the occupant captured by an indoor camera (30) that captures the interior of the vehicle. and
   When the pull-in control unit determines that the physique of the occupant identified by the occupant-related state identification unit is larger than the physique of the occupant in the past when the occupant was lightly dressed, the physique of the occupant is determined as the reference for the occupant. A wakefulness maintaining device that increases the strength of the retraction stimulus for the seat belt worn by the occupant, compared to the case where it is not determined that the occupant is larger than the physique of the occupant.
8. The wakefulness maintenance device according to claim 6 or 7,
   The occupant-related state identification unit (101, 101a) identifies the physique of the occupant as the occupant-related state by recognizing the captured image of the occupant captured by an indoor camera (30) that captures the interior of the vehicle. and
   When the physique of the occupant identified by the occupant-related state identification unit is equal to or greater than a specified value, the seat belt worn by the occupant is more likely to be seat belt-tight than when the physique of the occupant is less than the specified value. A wakefulness maintenance device that increases the intensity of the withdrawal stimulus.
9. The wakefulness maintenance device according to any one of claims 1 to 8,
   The occupant-related state identification unit (101, 101b, 101c) identifies a state related to the driver of the vehicle as the occupant-related state,
   The pull-in control unit is an awake maintenance device that causes the pull-in stimulus to be applied to the seat belt worn by the driver.
10. The wakefulness maintenance device according to any one of claims 1 to 8,
    The occupant-related state identification unit (101a) identifies a state related to the driver and fellow passengers of the vehicle as the occupant-related state,
    The pull-in control unit (104a) is capable of causing the pull-in stimulus for seat belts worn by the driver and the passenger, and the drowsiness of the driver specified by the occupant-related condition specifying unit. If it is less than the second threshold, the retraction stimulus for the seat belt worn by the fellow passenger is not performed, while the drowsiness of the driver identified by the occupant-related condition identification unit is equal to or greater than the second threshold. Based on this, an arousal maintaining device for performing the retraction stimulus for the seat belt worn by the fellow passenger.
11. The wakefulness maintenance device according to claim 10,
    Even if the driver's drowsiness specified by the occupant-related state specifying unit is equal to or greater than the second threshold value, the pull-in control unit determines whether the posture or the seat of the fellow passenger specified by the occupant-related state specifying unit is a state in which the effect of the retraction stimulus is estimated to be low, the wakefulness maintaining device does not apply the retraction stimulus to the seat belt worn by the fellow passenger.
12. A wakefulness maintenance method that can be used in a vehicle, comprising:
    executed by at least one processor;
    an occupant-related condition identifying step of identifying an occupant-related condition, which is a condition associated with the occupant, including at least a degree of drowsiness of the occupant of the vehicle;
    a pull-in control step of performing a pull-in stimulus, which is a pull-in stimulus of the seat belt worn by the occupant, based on the fact that the degree of drowsiness of the occupant identified in the occupant-related state identification step is equal to or greater than a predetermined threshold; including
    The method for maintaining wakefulness, wherein in the attraction control step, a mode of the attraction stimulus is changed in accordance with the occupant-related state identified in the occupant-related state identification step.

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