Vehicular seat

Abstract

To surely provide a stimulus for promoting a user whose wakefulness level has deteriorated to wake up.SOLUTION: A vehicular seat 1, which comprises a seat cushion 4 for supporting the hip of a user from below and is provided on a floor 3 of a vehicle, further comprises: a seating face angle change actuator 10 that changes a seating face angle θ which is an angle formed by a reference surface R set on the floor 3 and the seat cushion 4; at least one or more wakefulness level sensors 18 and 21 that detect a wakefulness level of the user; and a control device 16 that is connected to wakefulness level sensors 18 and 21 and the seating face angle change actuator 10 and controls the seating face angle change actuator 10. The control device 16 executes wake-up processing for making the seating face angle change actuator 10 change the seating face angle θ, on the basis of the wakefulness level.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a vehicle seat.

Background Art

[0002] When the driver's wakefulness decreases, there is a technology to stimulate the driver to increase the driver's wakefulness. For example, Patent Document 1 describes a vehicle wake-up system that inflates an airbag provided in the seat back when the driver's wakefulness decreases, and the airbag presses against the driver's back to stimulate it.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the posture of a driver with low wakefulness is leaning forward and the driver's back is separated from the seat back, there is a possibility that the back of the driver with low wakefulness cannot be sufficiently stimulated by the airbag even when using the vehicle wake-up system described in Patent Document 1.

[0005] In view of the above background, an object of the present invention is to provide a vehicle seat that can surely give a stimulating wake-up to a user with decreased wakefulness.

Means for Solving the Problems

[0006] In order to solve the above problems, one aspect of the present invention is a vehicle seat (1) provided on a vehicle floor (3) and having a seat cushion (4) that supports a user's buttocks from below, the seat surface angle (θ) being the angle formed between a reference plane (R) set with respect to the floor and the seat cushion, a seat surface angle changing actuator (10) that changes the seat surface angle, at least one arousal level sensor (18, 21) that detects the arousal level of the user, and a control device (16) connected to the arousal level sensor and the seat surface angle changing actuator and controlling the seat surface angle changing actuator, wherein the control device executes an arousal process for changing the seat surface angle of the seat surface angle changing actuator based on the arousal level.

[0007] According to this aspect, the vehicle seat executes an arousal process for changing the seat surface angle of the seat surface angle changing actuator based on the arousal level. Since a user with a decreased arousal level is sitting on the seat cushion, it is possible to surely give a stimulus for promoting arousal to the user with a decreased arousal level.

[0008] In the above aspect, when the arousal level is equal to or lower than a first arousal level threshold, the control device may execute the arousal process of generating vibrations in which the seat surface angle increases and decreases at a predetermined vibration cycle for a predetermined duration.

[0009] According to this aspect, the arousal process is a process of generating vibrations in which the seat surface angle increases and decreases at a predetermined vibration cycle for a predetermined duration. By generating vibrations in which the seat surface angle increases and decreases at a predetermined vibration cycle, it is possible to surely give a stimulus for promoting arousal to the user during the duration.

[0010] In the above aspect, the control device may execute the arousal process of making the duration longer as the arousal level is lower than the first arousal level threshold.

[0011] According to this aspect, the lower the user's arousal level is than the first arousal threshold, the stronger the stimulus the user receives. Therefore, even when the user's arousal level significantly decreases, an effective stimulus for promoting arousal can be given to the user so that the user's arousal level is likely to increase.

[0012] In the above aspect, the control device may execute the arousal process of increasing the amplitude of the vibration as the arousal level is lower than the first arousal threshold.

[0013] According to this aspect, the lower the user's arousal level is than the first arousal threshold, the stronger the stimulus the user receives. Therefore, even when the user's arousal level significantly decreases, an effective stimulus for promoting arousal can be given to the user so that the user's arousal level is likely to increase.

[0014] In the above aspect, the control device may execute the arousal process of shortening the vibration period as the arousal level is lower than the first arousal threshold.

[0015] According to this aspect, the lower the user's arousal level is than the first arousal threshold, the stronger the stimulus the user receives. Therefore, even when the user's arousal level significantly decreases, an effective stimulus for promoting arousal can be given to the user so that the user's arousal level is likely to increase.

[0016] In the above aspect, the arousal process may be a process of generating the vibration in which the seat surface angle increases and decreases for the duration, centered on a vibration reference angle that is a predetermined angle smaller than the immediately preceding seat surface angle immediately before executing the arousal process.

[0017] According to this aspect, in the awakening process, the average state of the seating surface of the vibrating seat cushion is inclined downward and forward with respect to the seating surface immediately before the execution of the awakening process (seating surface at the vibration reference angle). In the state where this seating surface is inclined downward and forward, the upper body of the user is likely to be in an unstable posture inclined forward. The fact that the user is likely to be in an unstable posture provides a stronger stimulus to the user. Therefore, a more effective stimulus can be given so as to easily increase the user's level of wakefulness.

[0018] In the above aspect, the vibration in the awakening process preferably includes a portion where the seating surface (S) of the seat cushion is in a state of being inclined downward and forward with respect to the reference surface.

[0019] According to this aspect, when the seat surface angle θ is less than 0, since the seating surface of the seat cushion is inclined downward and forward, the upper body of the user is likely to be in an unstable posture inclined forward. The fact that the user is likely to be in an unstable posture provides a stronger stimulus to the user. Therefore, an effective stimulus can be given to the user so as to easily increase the user's level of wakefulness.

[0020] In the above aspect, a plurality of wakefulness sensors may be provided, and the control device may calculate the level of wakefulness based on the outputs of the plurality of wakefulness sensors.

[0021] According to this aspect, the control device can calculate a more appropriate value of the level of wakefulness.

[0022] In the above aspect, the control device is connected to an input / output device (14) that receives an input operation of mode identification information for identifying whether it is in the wake mode or the relaxation mode. Based on the input of the mode identification information from the input / output device, it selects either the wake mode or the relaxation mode. When the wake mode is selected, if the level of wakefulness is equal to or lower than a first wakefulness threshold value, the wake-up process is executed. When the relaxation mode is selected, if the level of wakefulness is equal to or lower than a second wakefulness threshold value, it is determined whether the seat surface angle is equal to or less than a front-up angle that is a predetermined angle larger than the standard seat surface angle, which is the standard seat surface angle. When it is determined that the seat surface angle is equal to or less than the front-up angle, the seat surface angle may be changed to the front-up angle.

[0023] According to this aspect, the control device changes the seat surface angle to the front-up angle. When the seat surface angle is at the front-up angle that is a predetermined angle larger than the standard seat surface angle, the seating surface of the seat cushion is inclined upward. As a result, the upper body of the user is likely to tilt backward. When the upper body of the user tilts backward, the upper body of the user is supported by the seat back, and the lower body of the user is supported by the seating surface. Thereby, it can be expected that the user can easily maintain a relaxed state.

[0024] In the above aspect, the seat surface angle changing actuator is provided in each of the left part (111L) and the right part (111R) of the seat cushion. The control device can change the left seat surface angle (θL) of the left part of the seat cushion and the right seat surface angle (θR) of the right part of the seat cushion to different angles from each other, and based on the level of wakefulness, it is preferable to execute a wake-up process for changing the left seat surface angle and the right seat surface angle to different angles from each other.

[0025] According to this aspect, in the wake-up process, since the left seat surface angle and the right seat surface angle are at different angles from each other, the seating surface of the seat cushion can be inclined left and right. As a result, the upper body of the user is likely to sway left and right, so an effective stimulus for awakening can be given to a user with a reduced level of wakefulness.

Advantages of the Invention

[0026] In order to solve the above problems, one aspect of the present invention is a vehicle seat (1) provided on a floor (3) of a vehicle, having a seat cushion (4) that supports a user's buttocks from below, the seat surface angle (θ) being the angle formed between a reference plane (R) set with respect to the floor and the seat cushion, a seat surface angle changing actuator (10) that changes the seat surface angle, at least one arousal sensor (18, 21) that detects the arousal level of the user, and a control device (16) connected to the arousal sensor and the seat surface angle changing actuator and controlling the seat surface angle changing actuator. The control device executes an arousal process for changing the seat surface angle of the seat surface angle changing actuator based on the arousal level.

[0027] According to this aspect, the vehicle seat executes an arousal process for changing the seat surface angle of the seat surface angle changing actuator based on the arousal level. Since a user with a decreased arousal level is sitting on the seat cushion, a stimulus that promotes arousal can be surely given to the user with a decreased arousal level.

[0028] In the above aspect, when the arousal level is equal to or lower than a first arousal level threshold, the control device may execute the arousal process of generating vibrations in which the seat surface angle increases and decreases at a predetermined vibration cycle for a predetermined duration.

[0029] According to this aspect, the arousal process is a process of generating vibrations in which the seat surface angle increases and decreases at a predetermined vibration cycle for a predetermined duration. By generating vibrations in which the seat surface angle increases and decreases at a predetermined vibration cycle, a stimulus that promotes arousal can be surely given to the user during the duration.

[0030] In the above aspect, the control device may execute the arousal process of making the duration longer as the arousal level is lower than the first arousal level threshold.

[0031] According to this aspect, the lower the user's arousal level is than the first arousal threshold, the stronger the stimulus the user receives. Therefore, even when the user's arousal level significantly decreases, an effective stimulus for promoting arousal can be given to the user so that the user's arousal level is likely to increase.

[0032] In the above aspect, the control device may execute the arousal process of increasing the amplitude of the vibration as the arousal level is lower than the first arousal threshold.

[0033] According to this aspect, the lower the user's arousal level is than the first arousal threshold, the stronger the stimulus the user receives. Therefore, even when the user's arousal level significantly decreases, an effective stimulus for promoting arousal can be given to the user so that the user's arousal level is likely to increase.

[0034] In the above aspect, the control device may execute the arousal process of shortening the vibration period as the arousal level is lower than the first arousal threshold.

[0035] According to this aspect, the lower the user's arousal level is than the first arousal threshold, the stronger the stimulus the user receives. Therefore, even when the user's arousal level significantly decreases, an effective stimulus for promoting arousal can be given to the user so that the user's arousal level is likely to increase.

[0036] In the above aspect, the arousal process may be a process of generating the vibration in which the seat surface angle increases and decreases for the duration, centered on a vibration reference angle that is smaller than the immediately preceding seat surface angle immediately before executing the arousal process by a predetermined angle.

[0037] According to this aspect, in the awakening process, the average state of the seating surface of the vibrating seat cushion is inclined downward and forward compared to the seating surface immediately before the execution of the awakening process (the seating surface at the vibration reference angle). In the state where this seating surface is inclined downward and forward, the upper body of the user is likely to be in an unstable posture tilted forward. The fact that the user is likely to be in an unstable posture provides a stronger stimulus to the user. Therefore, a more effective stimulus can be given so that the awakening level of the user can be easily increased.

[0038] In the above aspect, the vibration in the awakening process preferably includes a portion where the seating surface (S) of the seat cushion is in a state of being inclined downward and forward compared to the reference surface.

[0039] According to this aspect, when the seat surface angle θ is less than 0, since the seating surface of the seat cushion is inclined downward and forward, the upper body of the user is likely to be in an unstable posture tilted forward. The fact that the user is likely to be in an unstable posture provides a stronger stimulus to the user. Therefore, an effective stimulus can be given to the user so that the awakening level of the user can be easily increased.

[0040] In the above aspect, a plurality of awakening level sensors may be provided, and the control device may calculate the awakening level based on the outputs of the plurality of awakening level sensors.

[0041] According to this aspect, the control device can calculate a more appropriate value of the awakening level.

[0042] In the above aspect, the control device is connected to an input / output device (14) that receives an input operation of mode identification information for identifying whether it is in the wake mode or the relaxation mode. Based on the input of the mode identification information from the input / output device, it selects either the wake mode or the relaxation mode. When the wake mode is selected, if the level of wakefulness is equal to or lower than a first wakefulness threshold, the wake-up process is executed. When the relaxation mode is selected, if the level of wakefulness is equal to or lower than a second wakefulness threshold, it is determined whether the seat surface angle is equal to or less than a front-up angle that is a predetermined angle larger than the standard seat surface angle, which is the standard seat surface angle. When it is determined that the seat surface angle is equal to or less than the front-up angle, the seat surface angle may be changed to the front-up angle.

[0043] According to this aspect, the control device changes the seat surface angle to the front-up angle. When the seat surface angle is the front-up angle that is a predetermined angle larger than the standard seat surface angle, the seating surface of the seat cushion is inclined upward. As a result, the upper body of the user is likely to tilt backward. When the upper body of the user tilts backward, the upper body of the user is supported by the seat back, and the lower body of the user is supported by the seating surface. Thereby, it can be expected that the user can easily maintain a relaxed state.

[0044] In the above aspect, the seat surface angle changing actuator is provided in each of the left part (111L) and the right part (111R) of the seat cushion. The control device can change the left seat surface angle (θL) of the left part of the seat cushion and the right seat surface angle (θR) of the right part of the seat cushion to different angles, and may execute a wake-up process of changing the left seat surface angle and the right seat surface angle to different angles based on the level of wakefulness.

[0045] According to this aspect, in the wake-up process, since the left seat surface angle and the right seat surface angle become different angles, the seating surface of the seat cushion can be inclined left and right. As a result, the upper body of the user is likely to sway left and right, so an effective stimulus for waking up can be given to a user with a reduced level of wakefulness.

Brief Description of the Drawings

[0046]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

[0047] Hereinafter, with reference to the drawings, the vehicle seat 1 according to an embodiment of the present invention will be described. FIG. 1 shows a deformed state of the vehicle seat 1, FIG. 2 shows the configuration of a vehicle V equipped with the vehicle seat 1, and FIG. 3 is a block diagram of a system 2 related to the vehicle seat 1. In the following description, unless otherwise specified, the "front-rear direction", "left-right direction", and "up-down direction" mean the front-rear direction, left-right direction, and up-down direction of the vehicle V. Also, a direction based on the vehicle seat 1, such as the "front-rear direction of the seat", means the direction as seen from a user seated on the vehicle seat 1.

[0048] [[First Embodiment]] As shown in FIGS. 1 and 2, the vehicle seat 1 is installed on the floor 3 in the passenger compartment of the vehicle V. The vehicle seat 1 includes a seat cushion 4, a seat back 5 supported at the rear of the seat cushion 4, and a headrest 6 connected to the upper part of the seat back 5. The seat cushion 4 supports the user's buttocks from below, the seat back 5 supports the user's back from the rear in the seat front-rear direction, and the headrest 6 supports the user's head from the rear in the seat front-rear direction. The seat cushion 4 and the seat back 5 each include a frame, a pad supported by the frame, and a skin material covering the surface of the pad on the user side (not shown).

[0049] A rotating device 8 is supported on the floor 3 via a sliding device 7. The rotating device 8 rotatably supports a support member 9 with respect to the sliding device 7 about a vertical axis Z passing through substantially the center in the seat front-rear direction and the seat width direction. The front end of the seat cushion 4 or the vicinity thereof is tiltably connected to the front end of the support member 9 about a tilting axis Y1 in the seat width direction. A seat surface angle changing actuator 10 that can expand and contract in its extending direction is pivotally connected at one end to a position below and / or behind the seat with respect to the tilting axis Y1 of the support member 9 and at the other end to a position behind the seat of the seat cushion 4 about an axis in the seat width direction. As the seat surface angle changing actuator 10, an electric cylinder, an air cylinder, or a hydraulic cylinder having a motor may be used.

[0050] The angle that varies around the tilting axis Y1 formed by the reference plane R (floor surface) orthogonal to the vertical direction and the seating surface S of the seat cushion 4 is defined as the seat surface angle θ (thigh angle). The support member 9 and the seat surface angle changing actuator 10 constitute the main part of a seat surface angle changing device 11 that changes the seat surface angle θ. Since the seating surface S deforms during actual seating, strictly speaking, it is set with reference to the seat frame. When viewed from the side of the seat, the three points of the tilting axis Y1 and the two rotatable connection points of the seat surface angle changing actuator 10 to the support member 9 and the seat cushion 4 are not arranged on the same straight line, that is, they are arranged to form the vertices of a triangle. Therefore, when the seat surface angle changing actuator 10 expands and contracts, the seat surface angle θ is changed. The seat surface angle changing device 11 can tilt the seat cushion 4 around the tilting axis Y1 between a state where the front end of the seating surface S is tilted downward with respect to the reference plane R (a state where the seat surface angle θ is negative, see Fig. 1(A)) and a state where the front end of the seating surface S is tilted upward with respect to the reference plane R (a state where the seat surface angle θ is positive, see Fig. 1(C)).

[0051] In the illustrated example, the tilting axis Y1 is arranged at the front end of the seat cushion 4, but the tilting axis Y1 may be arranged at any position from the front end to the rear end of the seat cushion 4, and the seat surface angle changing device 11 may have a configuration that allows the seat cushion 4 to tilt with respect to the reference plane R.

[0052] As shown in Figs. 2 and 3, the system 2 includes an in-vehicle monitoring device 12 that acquires information inside the vehicle cabin, an out-of-vehicle monitoring device 13 that acquires information outside the vehicle, an input / output device 14 that receives and provides information to the user, a vehicle state monitoring device 15 that acquires information regarding the state of the vehicle V, a control device 16 that receives information from the in-vehicle monitoring device 12, the out-of-vehicle monitoring device 13, the input / output device 14, and the vehicle state monitoring device 15 and transmits the information to the input / output device 14, and a plurality of controlled devices 17 controlled by the control device 16.

[0053] The in-vehicle monitoring device 12 includes one or more in-vehicle cameras 18 that image the interior of the vehicle, a plurality of object sensors 19 provided on the vehicle seat 1, a seating sensor 20 provided on the seat cushion 4, a biological sensor 21, and a seat surface angle sensor 22.

[0054] The in-vehicle camera 18 is arranged at a position where it can image the user and the periphery of the vehicle seat 1. The in-vehicle camera 18 may be composed of a CMOS image sensor. The in-vehicle camera 18 is preferably composed of a compound eye camera including a plurality of imaging elements and is capable of distance imaging based on triangulation such as stereo measurement or the light section method.

[0055] The object sensor 19 is a sensor that detects objects inside the vehicle and may be a proximity sensor, a lidar, an ultrasonic sensor, etc. Alternatively, the object sensor 19 may be composed of a ToF (Time of Flight) sensor module that includes a light source and a detector and performs distance measurement by acquiring the time until the light emitted from the light source reaches the detector. The object sensor 19 may be arranged, for example, along the outer peripheral surface of the seat cushion 4 or may be provided at an appropriate position on the headrest 6. Also, the object sensors 19 may be arranged side by side in the front-rear direction on the door panel or the floor 3.

[0056] The seating sensor 20 may be a membrane switch or an electrostatic sensor provided on the seat cushion 4. The seating sensor 20 detects the pressure applied to the seat cushion 4, and the control device 16 that receives the detection result determines whether the user is seated on the vehicle seat 1. A seat belt reminder (SBR) system that issues an alarm when the user is seated on the vehicle seat 1 but not wearing the seat belt is adopted, and the seating determination using the seating sensor 20 is performed to determine whether an alarm is required, etc.

[0057] The biological sensor 21 may be a heart rate sensor, a respiration sensor, a pressure sensor, or an electroencephalogram sensor. The heart rate sensor is provided on the front surface of the seat back 5, and preferably, is disposed at a position corresponding to the user's heart. The heart rate sensor is a sensor that detects the user's heart rate. The heart rate sensor may be based on any of a touch type, an optical type, and an electrocardiogram type. The respiration sensor is a sensor that detects the user's respiration rate and the depth of respiration. The respiration sensor may be, for example, a type that detects the pressure applied from the user at a position corresponding to the user's lungs on the front surface of the seat back 5 and reads the pressure change caused by the user's respiratory movement. The respiration sensor may be based on a method of providing two sheet-like electrodes along the front surface of the seat back 5 and detecting the variation in the capacitance between the electrodes due to the movement of the human chest. The pressure sensor is a sensor used to detect the user's posture based on the pressure applied to the seat cushion 4 and the seat back 5. The pressure sensor is provided in a planar shape on the surfaces of the seat cushion 4 and the seat back 5 facing the user, measures the in-plane distribution (pressure distribution) of the pressure applied from the user to them, and detects the user's posture. The electroencephalogram sensor includes a magnetic sensor provided at a position facing the user's head in the headrest 6. The magnetic sensor detects the magnetic signal associated with the activity of the user's brain cells. The electroencephalogram sensor calculates the user's electroencephalogram based on the magnetic signal. As the electroencephalogram sensor, a magnetic sensor provided at a position facing the user's head in the headrest 6 may be used, and the control device 16 may calculate the user's electroencephalogram based on the magnetic signal.

[0058] The seat surface angle sensor 22 is provided between the support member 9 and the frame of the seat cushion 4 or in the seat surface angle changing actuator 10, and detects the seat surface angle θ (see FIG. 1) or the information for calculating the seat surface angle θ.

[0059] The outside vehicle monitoring device 13 includes one or more outside vehicle photographing cameras 23 and a plurality of radars 24 and / or lidars 25 (LiDAR).

[0060] The outside vehicle camera 23 images the surroundings of the vehicle V, including objects existing around the vehicle V (e.g., surrounding vehicles and pedestrians), guardrails, curbs, walls, median strips, the shape of the road, road markings drawn on the road, etc. The outside vehicle camera 23 may be, for example, a digital camera using a solid-state imaging device such as a CCD or a CMOS. The outside vehicle camera 23 is provided, for example, on the ceiling inside the vehicle compartment and images the outside of the vehicle through the front glass, rear glass, or side glass. The outside vehicle camera 23 may be, for example, a stereo camera.

[0061] The radar 24 emits radio waves such as millimeter waves around the vehicle V and detects the position (distance and direction) of an object by capturing the reflected wave. The lidar 25 irradiates light such as infrared rays around the vehicle V and detects the position (distance and direction) of an object by capturing the reflected light. The radar 24 and / or the lidar 25 are attached outside the vehicle compartment of the vehicle V. The radar 24 and / or the lidar 25 include, for example, those that irradiate radio waves / light forward of the vehicle V, those that irradiate radio waves / light rearward of the vehicle V, and those that irradiate radio waves / light sideward of the vehicle V. The outside vehicle compartment monitoring device 13 may include a sonar.

[0062] The input / output device 14 receives an input operation by the user and notifies the user of various information by display or sound. The input / output device 14 may include, for example, a touch panel 26 that performs both input and output. In addition to or instead of the touch panel 26, the input / output device 14 may include an input device (e.g., buttons, switches, and / or a microphone 27 that receives the user's voice input) and an output device (e.g., a display and / or a speaker 28 that notifies sound). A mobile terminal such as a smartphone may be communicable with the control device 16 wirelessly or by wire and used as the input / output device 14.

[0063] The vehicle state monitoring device 15 includes a vehicle speed sensor 29, a brake sensor 30, a steering angle sensor 31, a shift lever sensor 32, and a door sensor 33. The vehicle speed sensor 29 detects the vehicle speed of the vehicle V. The brake sensor 30 includes a brake pedal sensor that detects the depression amount of the brake pedal and a parking brake sensor that detects the operation amount of the parking brake lever. The steering angle sensor 31 detects the steering angle of the steering wheel. The shift lever sensor 32 detects the position where the shift lever is placed, such as parking (P), reverse (R), neutral (N), drive (D), etc. The door sensor 33 detects the open / closed state of the door of the vehicle V.

[0064] The control device 16 is a so-called Electronic Control Unit, which controls the vehicle seat 1 based on the information acquired by the in-vehicle monitoring device 12, the out-vehicle monitoring device 13, and the vehicle state monitoring device 15, as well as the information input by the user to the input / output device 14. The control device 16 is composed of a computer including a processor 34 constituted by a CPU (Central Processing Unit) etc., a storage device 35 including a RAM (Random Access Memory), a ROM (Read Only Memory), and an SSD (Solid State Drive) and / or an HDD (Hard Disk Drive). The control device 16 is connected to the in-vehicle monitoring device 12, the out-vehicle monitoring device 13, the input / output device 14, the vehicle state monitoring device 15, and the device to be controlled 17 so that signals can be transmitted and received by signal lines or wirelessly. The control device 16 and the device to be controlled 17 are connected to a power source (not shown) mounted on the vehicle V and receive power supply from the power source. The control device 16 can acquire information regarding the vehicle seat 1, such as the state of the seat surface angle θ (see FIG. 1), based on the information acquired by the in-vehicle monitoring device 12 and the control history for the device to be controlled 17.

[0065] The controlled device 17 controlled by the control device 16 includes, in addition to the above-described slide device 7, rotation device 8, and seat surface angle changing device 11, a reclining device 36 that tilts the seat back 5, an airbag device 37 that protects the user during a collision of the vehicle V, a side support device 38 that changes the height of both side portions of the seat cushion 4, a seat heater 39 that warms the seat cushion 4, and a vibration device 40 that vibrates the seat cushion 4 to prompt the user's attention.

[0066] The control device 16 can calculate the seat surface angle θ from the detected value of the seat surface angle sensor 22. The seat surface angle sensor 22 may be, for example, an angle potentiometer provided between the support member 9 and the seat cushion 4. Further, the seat surface angle sensor 22 may be a stroke sensor that detects the length of the seat surface angle changing actuator 10, and the control device 16 may calculate the seat surface angle θ based on the length of the seat surface angle changing actuator 10. The control device 16 may also calculate the seat surface angle θ from the control history of the seat surface angle changing actuator 10.

[0067] The user can change the seat surface angle θ by operating the input / output device 14. The input / output device 14 outputs an operation signal corresponding to the user's operation to the control device 16. The control device 16 controls the seat surface angle changing actuator 10 based on the operation signal to change the seat surface angle θ to an angle within the changeable range. The changeable range is the range of angles at which the seat surface angle θ can be changed, and is defined by the minimum angle (see FIG. 1(A)) and the maximum angle (see FIG. 1(C)). The changeable range is set by the control device 16.

[0068] The reclining device 36 is a device that tilts the seat back 5 with respect to the seat cushion 4 around a tilting axis Y2 (see FIG. 1) extending in the seat width direction. The tilting axis Y2 extends to the rear end in the front-rear direction of the seat of the seat cushion 4 and the lower end of the seat back 5.

[0069] The vehicle seat 1 of the present embodiment can give a stimulus to prompt awakening to a user whose wakefulness has decreased. As a wakefulness sensor for detecting the wakefulness of the user, a biological sensor 21 or an in-vehicle camera 18 may be used. The control device 16 can calculate the wakefulness of the user based on the detection value of the biological sensor 21. Further, the control device 16 may calculate the wakefulness regarding the facial expression and pupils based on the captured image in which the in-vehicle camera 18 captures the face of the user.

[0070] The user can set the vehicle seat 1 to an awakening mode and a relaxation mode. The awakening mode is a mode in which the vehicle seat 1 gives a stimulus to prompt awakening to the user when the wakefulness of the user decreases. When the driver's seat is set to the awakening mode, a stimulus to prompt awakening can be given to the driver when the wakefulness of the driver decreases. The relaxation mode is a mode for adjusting the seat surface angle θ so that the user can easily maintain a relaxed state.

[0071] In order for the user to set the vehicle seat 1 to the awakening mode or the relaxation mode, the input / output device 14 includes a mode setting button (not shown). The mode setting button is a button that receives an input operation of mode identification information for identifying whether it is the awakening mode or the relaxation mode. The mode setting button may be a button displayed on the touch panel 26. The mode setting button may be a mechanical switch independent of the touch panel 26. When the mode setting button is pressed, the input / output device 14 outputs the mode identification information to the control device 16. The control device 16 selects whether it is the awakening mode or the relaxation mode based on the mode identification information.

[0072] <Processing of awakening mode> When the control device 16 selects the awakening mode, the control device 16 executes the first wakefulness monitoring process every predetermined time (for example, 100 ms). Hereinafter, with reference to FIG. 4, the details of the first wakefulness monitoring process will be described.

[0073] As shown in FIG. 4, in the first step ST11 of the first arousal level monitoring process, the control device 16 calculates the arousal level of the user. The control device 16 calculates the arousal level for each output of a plurality of arousal level sensors (the biological sensor 21 and the in-vehicle camera 18), and calculates the average of the arousal levels for the outputs of the plurality of arousal level sensors as the arousal level of the user. By calculating the arousal level based on the outputs of the plurality of arousal level sensors, the control device 16 can calculate a more appropriate value of the arousal level. The control device 16 may calculate the arousal level for the output of one arousal level sensor (the biological sensor 21 and the in-vehicle camera 18). When the control device 16 calculates the arousal level, it executes step ST12.

[0074] In step ST12, the control device 16 determines whether the arousal level is less than or equal to the first arousal level threshold. The first arousal level threshold may be determined as the value of the driver's arousal level when the driver is fully capable of driving. When the control device 16 determines that the arousal level is less than or equal to the first arousal level threshold (arousal level ≤ first arousal level threshold), the first arousal level monitoring process ends. When the control device 16 determines that the arousal level is not less than or equal to the first arousal level threshold (first arousal level threshold < arousal level), it executes ST13.

[0075] In step ST13, the control device 16 executes an arousal process. When the control device 16 executes the arousal process, the first arousal level monitoring process ends. Hereinafter, the details of the arousal process will be described with reference to FIG. 5.

[0076] As shown in FIG. 5, in the arousal process, the control device 16 controls the seat surface angle changing actuator 10 to generate a vibration Va in which the seat surface angle θ increases and decreases at a predetermined vibration period T for a predetermined duration tv. The vibration Va is a vibration that increases and decreases around the seat surface angle θ immediately before the execution of the arousal process (referred to as the "immediately preceding seat surface angle θo"). The lower the arousal level of the user is than the first arousal level threshold, the longer the control device 16 makes the duration tv, the shorter the vibration period T of the vibration Va of the seat surface angle θ, and the larger the amplitude A is.

[0077] As shown in FIG. 5, vibration V1 is the vibration V1 of the seat surface angle θ with respect to an arousal level D1 lower than the first arousal threshold (arousal level D1 < first arousal threshold). The vibration V2 shown in FIG. 5 is the vibration V2 of the seat surface angle θ with respect to an arousal level D2 lower than the arousal level D1 (arousal level D2 < arousal level D1 < first arousal threshold). The vibration period T2 of the vibration V2 is shorter than the vibration period T1 of the vibration V1 (vibration period T2 < vibration period T1). Also, the amplitude A2 of the vibration V2 is larger than the amplitude A1 of the vibration V1 (amplitude A1 < amplitude A2). The duration tv2 of the vibration V2 is longer than the duration tv1 of the vibration V1 (duration tv1 < duration tv2). Thus, in the arousal process, the control device 16 shortens the vibration period T of the vibration Va of the seat surface angle θ, increases the amplitude A of the vibration Va of the seat surface angle θ, and lengthens the duration tv as the arousal level of the user is lower than the first arousal threshold. Thereby, the lower the arousal level of the user is than the first arousal threshold, the stronger the stimulus the user receives.

[0078] At the trough of the vibration of the vibration V2, the seat surface angle θ is an angle smaller than 0 (seat surface angle θ < 0) (see FIG. 1(A)). Therefore, at the trough of the vibration of the vibration V2, the seating surface S of the seat cushion 4 is in a state of being lowered forward relative to the reference plane R (see FIG. 1(A)). Thus, the vibration V2 of the arousal process includes a portion where the seating surface S of the seat cushion 4 is in a state of being lowered forward relative to the reference plane R.

[0079] The control device 16 may make the amplitude A of the vibration Va of the seat surface angle θ constant regardless of the arousal level. 16 may make the vibration period T constant regardless of the arousal level. The control device 16 may make the duration tv constant regardless of the arousal level. The vibration Va of the seat surface angle θ may be a vibration other than a sine wave. For example, the vibration Va may be a triangular wave vibration.

[0080] The vehicle seat 1 executes an arousal process for changing the seat surface angle θ to the seat surface angle changing actuator 10 based on the arousal level. Since the user with a decreased arousal level is sitting on the seat cushion 4, it is possible to surely give a stimulus for promoting arousal to the user with a decreased arousal level.

[0081] The awakening process is a process of generating vibrations in which the seat surface angle θ increases and decreases at a predetermined vibration period T for a predetermined duration tv. By generating vibrations in which the seat surface angle θ increases and decreases at a predetermined vibration period T, it is possible to surely give the user a stimulus that promotes awakening for the duration tv.

[0082] In the awakening process, the vehicle seat 1 makes the duration tv of the seat surface angle θ longer as the awakening level of the user is lower than the first awakening level threshold. As a result, the user receives a stronger stimulus as the awakening level is lower than the first awakening level threshold. Therefore, even when the awakening level of the user has greatly decreased, it is possible to give the user a more effective stimulus for promoting awakening so that the awakening level of the user is likely to increase.

[0083] In the awakening process, the vehicle seat 1 makes the amplitude A of the vibration of the seat surface angle θ larger as the awakening level of the user is lower than the first awakening level threshold. As a result, the user receives a stronger stimulus as the awakening level is lower than the first awakening level threshold. Therefore, even when the awakening level of the user has greatly decreased, it is possible to give the user a more effective stimulus for promoting awakening so that the awakening level of the user is likely to increase.

[0084] In the awakening process, the vehicle seat 1 makes the vibration period T of the seat surface angle θ shorter as the awakening level of the user is lower than the first awakening level threshold. As a result, the user receives a stronger stimulus as the awakening level is lower than the first awakening level threshold. Therefore, even when the awakening level of the user has greatly decreased, it is possible to give the user a more effective stimulus for promoting awakening so that the awakening level of the user is likely to increase.

[0085] The vibration V2 of the awakening process includes a portion where the seating surface S of the seat cushion 4 is in a state of being lowered forward from the reference surface R. When the seating surface S of the seat cushion 4 is lowered forward, the upper body of the user is likely to be in an unstable posture tilted forward. The fact that the user is likely to be in an unstable posture is a stronger stimulus to the user. Therefore, it is possible to give the user an effective stimulus so that the awakening level of the user is likely to increase.

[0086] <Relaxation mode processing> When the control device 16 selects the relaxation mode, the control device 16 executes the second arousal level monitoring process every predetermined time (for example, 10 seconds). Hereinafter, with reference to FIG. 6, the details of the second arousal level monitoring process will be described.

[0087] As shown in FIG. 6, in the first step ST21 of the second arousal level monitoring process, the control device 16 calculates the arousal level of the user. The control device 16 calculates the arousal level for each output of a plurality of arousal level sensors (biological sensor 21, in-vehicle camera 18), and calculates the average of the arousal levels for the outputs of the plurality of arousal level sensors as the arousal level of the user. The control device 16 can calculate a more appropriate arousal level value by calculating the arousal level based on the outputs of the plurality of arousal level sensors. The control device 16 may calculate the arousal level for the output of one arousal level sensor (biological sensor 21, in-vehicle camera 18). When the control device 16 calculates the arousal level, it executes step ST22.

[0088] In step ST22, the control device 16 determines whether the arousal level is less than or equal to the second arousal level threshold. The second arousal level threshold may be determined as the arousal level value when the arousal level is lower than normal. When the control device 16 determines that the arousal level is less than or equal to the second arousal level threshold (arousal level ≤ second arousal level threshold), it executes ST23. When the control device 16 determines that the arousal level is not less than or equal to the second arousal level threshold (second arousal level threshold < arousal level), the second arousal level monitoring process ends.

[0089] In step ST23, the control device 16 determines whether the seat surface angle θ is less than or equal to the front upward angle θFU. The front upward angle θFU is an angle that is a predetermined angle larger than the standard seat surface angle (see FIG. 1(B)), which is the standard seat surface angle θ. When the control device 16 determines that the seat surface angle θ is less than or equal to the front upward angle θFU (seat surface angle θ ≤ front upward angle θFU), it executes ST24. When the control device 16 determines that the seat surface angle θ is not less than or equal to the front upward angle θFU (front upward angle θFU < seat surface angle θ), the second arousal level monitoring process ends.

[0090] In step ST24, the control device 16 changes the seat surface angle θ to the forward upward angle θFU. When the control device 16 changes the seat surface angle θ to the forward upward angle θFU, it ends the second arousal level monitoring process. Therefore, when the user's arousal level is equal to or lower than the second arousal level (arousal level ≤ second arousal level threshold value) (ST22: Yes), the seat surface angle θ is set to an angle equal to or greater than the forward upward angle θFU.

[0091] In step ST24, the control device 16 changes the seat surface angle θ to the forward upward angle θFU. When the seat surface angle θ is the forward upward angle θFU which is a predetermined angle larger than the standard seat surface angle, the seating surface S of the seat cushion 4 is inclined upward to the front. As a result, the upper body of the user tends to tilt backward. When the upper body of the user tilts backward, the upper body of the user is supported by the seat back 5, and the lower body of the user is supported by the seating surface S. Thereby, it can be expected that the user can easily maintain a relaxed state. Thus, in the relaxation mode, it can be expected that by changing the seat surface angle θ to the forward upward angle θFU, the user can easily maintain a relaxed state.

[0092] <<Second Embodiment>> As shown in FIG. 7, the arousal process of the present embodiment is a process of generating vibrations in which the seat surface angle θ increases and decreases around the vibration reference angle θce which is a predetermined angle smaller than the immediately preceding seat surface angle θo immediately before executing the arousal process. The configuration of the vehicle seat 1 of the present embodiment is the same as that of the vehicle seat 1 of the first embodiment shown in FIGS. 1-4.

[0093] The vehicle seat 1 calculates, in the wake-up process, a vibration reference angle θce that is smaller than the immediately preceding seat surface angle θo by a predetermined angle, and generates a vibration Va in which the duration tv and the seat surface angle θ increase and decrease around the vibration reference angle θce. In the wake-up process, the average state of the seating surface S of the vibrating seat cushion 4 is in a state inclined downward and forward (seating surface S at the vibration reference angle θce) compared to the seating surface S immediately before the wake-up process is executed. In this state where the seating surface S is inclined downward and forward, the upper body of the user is likely to be in an unstable posture inclined forward. The fact that the user is likely to be in an unstable posture provides a stronger stimulus to the user. Therefore, a more effective stimulus can be given so that the wakefulness of the user can be easily increased.

[0094] <<Third Embodiment>> As shown in FIGS. 8 and 9, in this embodiment, the pad and the skin material of the seat cushion 4 are divided into three parts: a left part 111L, a central part 111M, and a right part 111R. The seat surface angle changing device 11 (see FIG. 1) has, as a seat surface angle changing actuator 10, a seat surface angle changing actuator 10L provided in the left part 111L (see FIGS. 8 and 9) of the seat cushion 4 and a seat surface angle changing actuator 10R provided in the right part 111R.

[0095] The control device 16 can change the left seat surface angle θL of the left part 111L of the seat cushion 4 and the right seat surface angle θR of the right part 111R of the seat cushion 4 to different angles. The configuration of the vehicle seat 1 of this embodiment is the same as that of the vehicle seat 1 of the first embodiment shown in FIGS. 1 - 4 except for the seat cushion 4 and the seat surface angle changing actuators 10L and 10R.

[0096] Unlike the awakening process of the first embodiment, the awakening process of this embodiment changes the left seat surface angle θL and the right seat surface angle θR to different angles based on the user's level of wakefulness. When the control device 16 is not executing the awakening process, the control device 16 sets the left seat surface angle θL and the right seat surface angle θR to the same angle (left seat surface angle θL = right seat surface angle θR = seat surface angle θ). The control device 16 of this embodiment executes the first wakefulness monitoring process and the second wakefulness monitoring process in the same manner as the control device 16 of the first embodiment.

[0097] As shown in FIG. 10, in the awakening process of this embodiment, the control device 16 generates vibrations that increase and decrease the left seat surface angle θL, the right seat surface angle θR, and a predetermined duration tv. The control device 16 alternately generates the vibration VL1 of the left seat surface angle θL and the vibration VR1 of the right seat surface angle θR a predetermined number of times (three times in FIG. 10). In the awakening process, when the left seat surface angle θL and the right seat surface angle θR are different from each other, the seating surface S of the seat cushion 4 can be inclined left and right. As a result, the upper body of the user can easily sway left and right, so that an effective stimulus for awakening can be given to the user whose wakefulness has decreased.

[0098] The control device 16 may increase the number of times of generating vibrations of the vibration VL1 and the vibration VR1, shorten the vibration period T of the vibration Va of the seat surface angle θ, and increase the amplitude A of the vibration of the seat surface angle θ as the user's wakefulness is lower than the first wakefulness threshold.

[0099] As shown in FIG. 11, in the awakening process, the control device 16 may generate the vibration VL2 of the left seat surface angle θL and the vibration VR2 of the right seat surface angle θR. In the vibration VL2 and the vibration VR2, the phases of the vibrations are opposite to each other. Due to the vibration VL2 and the vibration VR2, the seating surface S of the seat cushion 4 can be inclined left and right. As a result, the upper body of the user can easily sway left and right, so that an effective stimulus for awakening can be given to the user whose wakefulness has decreased.

[0100] In the awakening process, the control device 16 may generate only one of the vibrations of the vibration VL2 and the vibration VR2.

[0101] The present invention is not limited to the above embodiments. The vehicle seat of the embodiment may be installed in a vehicle other than a car.

Explanation of Signs

[0102] 1: Vehicle seat 3: Floor 4: Seat cushion 10: Seat surface angle change actuator 10L: Seat surface angle change actuator 10R: Seat surface angle change actuator 14: Input / output device 16: Control device 18: In-vehicle camera 21: Biosensor 111L: Left part 111R: Right part R: Reference plane S: Seating surface θ: Seat surface angle

Claims

1. A vehicle seat having a seat cushion that supports a user's buttocks from below and is provided on a floor of the vehicle, a seat angle changing actuator for changing a seat angle, which is an angle between the seat cushion and a reference plane set with respect to the floor; At least one alertness sensor for detecting an alertness of the user; A control device connected to the wakefulness sensor and the seat angle changing actuator and controlling the seat angle changing actuator, The control device includes: The vehicle seat executes an awakening process for causing the seat angle changing actuator to change the seat angle based on the awakening degree.

2. The control device includes:

2. The vehicle seat according to claim 1, wherein, when the level of awakening is equal to or lower than a first awakening level threshold, the awakening process is executed to generate vibrations for a predetermined duration in which the seat angle increases and decreases at a predetermined vibration period.

3. The control device includes: The vehicle seat according to claim 2 , wherein the awakening process is executed to extend the duration as the awakening level is lower than the first awakening level threshold.

4. The control device includes: The vehicle seat according to claim 2 , wherein the awakening process is executed to increase the amplitude of the vibration as the awakening level is lower than the first awakening level threshold.

5. The control device includes: The vehicle seat according to claim 2 , wherein the awakening process is executed to shorten the vibration period as the awakening level is lower than the first awakening level threshold.

6. 3. The vehicle seat according to claim 2, wherein the awakening process generates the vibration for the duration and the seat angle increasing or decreasing around a vibration reference angle that is a predetermined angle smaller than the previous seat angle immediately before the awakening process is executed.

7. The vehicle seat according to claim 2 , wherein the vibration of the awakening process includes a portion where the seating surface of the seat cushion is lowered forward than the reference surface.

8. A plurality of the wakefulness sensors are provided, The vehicle seat according to claim 1 , wherein the control device calculates the level of awakening based on outputs of the plurality of awakening level sensors.

9. The control device includes: The device is connected to an input / output device that receives input operation of mode specification information for specifying whether the device is in the wakefulness mode or the relaxation mode, selecting the wakefulness mode or the relaxation mode based on the input of the mode specifying information from the input / output device; When the awakening mode is selected, When the awakening level is equal to or lower than a first awakening level threshold, the awakening process is executed; When the relax mode is selected, When the awakening level is equal to or lower than a second awakening level threshold, it is determined whether the seat angle is equal to or lower than a front-upward angle that is a predetermined angle larger than a standard seat angle that is a standard seat angle, The vehicle seat according to claim 1 , wherein when the seating surface angle is determined to be equal to or smaller than the front-upper angle, the seating surface angle is changed to the front-upper angle.

10. The seat angle changing actuator is The seat cushion is provided on the left and right sides, The control device includes: A left seating surface angle of the left portion of the seat cushion and a right seating surface angle of the right portion of the seat cushion can be changed to angles different from each other, The vehicle seat according to claim 1 , wherein the awakening process is executed to change the left seating surface angle and the right seating surface angle to angles different from each other based on the awakening degree.

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