Vehicle seat control device

Abstract

To provide a vehicle seat control device which improves safety property at the time of a vehicle front collision while a crewman is in a state of sleep without losing a degree of freedom of attitude when a crewman is awake.SOLUTION: A vehicle seat control device is given in which: a crewman monitoring device 48 detects whether a crewman 12 seating on a vehicle seat 10 with a crewman restraint device (driving seat airbag device 14 and knee airbag device 18) at a vehicle front side falls asleep or is awake; a seat operative mechanism displaces the vehicle seat 10 with driving force of a motor; a seat control ECU controls, when the crewman monitoring device 48 detects the crewman 12 falls asleep, the seat operative mechanism to displace the vehicle seat 10 so that distance between the crewman restraint device and the crewman become shorter (refer to (B)); and the seat control ECU controls, when the crewman monitoring device 48 detects the crewman 12 is awake, the seat operative mechanism to return the vehicle seat 10 to a position where the vehicle seat is located before falling asleep (refer to (A)).SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a vehicle seat control device.

Background Art

[0002] Patent Document 1 discloses a technique for estimating a passenger's sleep desire based on imaging information captured by a camera or the like in a vehicle seat, and controlling the seat back to a reclined state when it is estimated that the sleep desire (sleepiness) is strong.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technique described in Patent Document 1 can be considered to improve the comfort of the passenger by automatically controlling the seat back to a reclined state when the passenger's sleep desire is strong. However, Patent Document 1 does not describe the safety when a frontal collision (hereinafter referred to as a front collision) of the vehicle occurs while the seat back is in the reclined position.

[0005] When an occupant sitting on a seat assumes a comfortable position for the purpose of sleeping, it is common to recline the seat back backward and slide the seat cushion backward to ensure freedom of movement. However, in this comfortable position, the distance between the occupant restraint device (a frontal airbag device that inflates and deploys toward the rear of the vehicle during a frontal collision: a driver's seat airbag device and a passenger seat airbag device) provided on the front side of the vehicle of the seat and the occupant increases. Therefore, it takes time for the restraint force to be exerted on the occupant during a frontal collision of the vehicle, which may result in insufficient restraint force or the inability to achieve appropriate occupant restraint. Also, for the knee airbag device installed in some vehicles, for the same reason, there is a possibility that insufficient restraint force may occur or appropriate occupant restraint may not be achieved when the occupant assumes a comfortable position. On the other hand, when the occupant is awake, there is a contradiction in that, considering the freedom of movement, the occupant wants to keep as far away as possible from the steering wheel and the instrument panel.

[0006] The present disclosure has been made in consideration of the above facts, and an object is to obtain a vehicle seat control device that can improve the safety during a frontal collision of the vehicle when the occupant is asleep without impairing the freedom of movement of the occupant during the period when the occupant is awake.

Means for Solving the Problems

[0007] A vehicle seat control device according to a first aspect includes an occupant restraint device that deploys an airbag toward the rear side of the vehicle during a frontal collision of the vehicle, a detection unit that detects the sleep and wakefulness of an occupant sitting on a seat provided on the front side of the vehicle where the occupant restraint device is provided, a seat actuation mechanism that displaces the seat by the driving force of a motor, and when the detection unit detects that the occupant is asleep, the seat actuation mechanism displaces the seat so that the distance between the occupant restraint device and the occupant becomes smaller, and then when the detection unit detects that the occupant is awake, a control unit that, by the seat actuation mechanism, returns the position of the seat to the position before sleep or displaces the seat to a position according to the input of the occupant.

[0008] In a first aspect, when the control unit detects that the occupant has fallen asleep by the detection unit, the control unit displaces the seat by the seat actuation mechanism so that the distance between the occupant restraint device and the occupant becomes smaller. Thereby, the timing of occupant restraint during a vehicle frontal collision can be advanced, and the safety during a vehicle frontal collision while the occupant is asleep can be improved. Further, in the first aspect, when the control unit subsequently detects that the occupant has woken up by the detection unit, the control unit returns the position of the seat to the position before falling asleep or displaces the seat to a position according to the input of the occupant by the seat actuation mechanism. Thereby, the degree of freedom of the posture during the period when the occupant is awake can be ensured.

Advantages of the Invention

[0009] The present disclosure has an effect that the safety during a frontal collision while the occupant is asleep can be improved without impairing the degree of freedom of the posture during the period when the occupant is awake.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] Hereinafter, an example of an embodiment of the present disclosure will be described in detail with reference to the drawings. The vehicle seat 10 shown in FIG. 1 is provided in the front seat of the vehicle and is seated by the occupant 12 who has boarded the vehicle. The vehicle seat 10 is an example of the seat in the present disclosure.

[0012] On the vehicle front side of the vehicle seat 10, there are arranged a steering wheel 16 to which a driver's airbag device 14 is attached, and an instrument panel 20 incorporating a passenger seat airbag device (not shown) and a knee airbag device 18. The driver's airbag device 14 and the knee airbag device 18 deploy an airbag to a predetermined deployment area on the rear side of the vehicle during a frontal collision of the vehicle. The driver's airbag device 14 and the knee airbag device 18 are an example of an occupant restraint device in the present disclosure, and are shown as an occupant restraint device 22 in FIG. 2.

[0013] The vehicle seat 10 includes a seat cushion portion 24, a seat back portion 30, and a headrest portion 32. Further, the vehicle seat 10 is a so-called power seat and incorporates a seat actuating mechanism 38 (see FIG. 2). The headrest portion 32 is attached to the upper end portion of the seat back portion 30 in the vehicle vertical direction so as to be slidable along the longitudinal direction of the seat back portion 30.

[0014] The lower end portion of the seat back portion 30 in the vehicle vertical direction is attached to the rear end portion of the seat cushion portion 24 in the vehicle front-rear direction via a rotation mechanism (not shown), and is rotatable about an axis along the vehicle width direction (in the directions of arrow A and arrow B in FIG. 1) with respect to the seat cushion portion 24.

[0015] The seat actuating mechanism 38 includes a reclining motor 40 (see FIG. 2), and the rotation axis of the reclining motor 40 is connected to the above-described rotation mechanism via a speed reduction mechanism (not shown). Therefore, when the reclining motor 40 is driven, the seat back portion 30 is rotated in the direction of arrow A or arrow B in FIG. 1 with respect to the seat cushion portion 24 according to the rotation direction of the rotation axis.

[0016] In addition, seat rails 34 are disposed along the longitudinal direction of the vehicle on the floor surface of the vehicle. An engaging mechanism that engages with the seat rail 34 and is slidable along the seat rail 34 is attached to the bottom portion (base portion 26 described later) of the seat cushion portion 24. The seat cushion portion 24, that is, the vehicle seat 10, is slidable in the longitudinal direction of the vehicle (in the directions of arrows C and D in FIG. 1) along the seat rail 34.

[0017] The seat actuating mechanism 38 includes a forward and backward slide motor 42 (see FIG. 2). The rotation force of the rotation shaft of the forward and backward slide motor 42 is transmitted to the seat rail 34 as a driving force for sliding the seat cushion portion 24 in the longitudinal direction of the vehicle via a speed reduction mechanism (not shown). For this reason, when the forward and backward slide motor 42 is driven, the vehicle seat 10 slides in the direction of arrow C or arrow D in FIG. 1 according to the rotation direction of the rotation shaft.

[0018] The seat cushion portion 24 includes a base portion 26 located on the lower side in the vertical direction of the vehicle and a moving portion 28 located on the upper side in the vertical direction of the vehicle relative to the base portion 26. A lifting mechanism (not shown) is provided between the base portion 26 and the moving portion 28, and the moving portion 28 is movable up and down in the vertical direction of the vehicle (in the directions of arrows E and F in FIG. 1) with respect to the base portion 26.

[0019] The seat actuating mechanism 38 includes a lifting motor 44 (see FIG. 2). The rotation shaft of the lifting motor 44 is connected to the above-described lifting mechanism via a speed reduction mechanism (not shown). For this reason, when the lifting motor 44 is driven, the moving portion 28 of the seat cushion portion 24 moves up and down in the direction of arrow E or arrow F in FIG. 1 with respect to the base portion 26 of the seat cushion portion 24 according to the rotation direction of the rotation shaft.

[0020] In addition, at the front end of the moving part 28 of the seat cushion part 24 in the vehicle longitudinal direction, the rear end of the ottoman part 36 in the vehicle longitudinal direction is connected via a rotation mechanism (not shown). The ottoman part 36 is rotatable with respect to the seat cushion part 24 (the moving part 28 thereof) in the vehicle vertical direction (the directions of arrow G and arrow H in FIG. 1).

[0021] The seat operation mechanism 38 includes an ottoman motor 46 (see FIG. 2). The rotation axis of the ottoman motor 46 is connected to the above-mentioned rotation mechanism via a speed reduction mechanism (not shown). Therefore, when the ottoman motor 46 is driven, the ottoman part 36 is rotated in the direction of arrow G or arrow H in FIG. 1 with respect to the moving part 28 of the seat cushion part 24 according to the rotation direction of its rotation axis.

[0022] As shown in FIG. 2, the seat operation mechanism 38 is connected to the seat control ECU 52. The seat control ECU 52 includes a CPU (Central Processing Unit) 54, a memory 56 such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a non-volatile storage unit 58 such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive), and an I / F (InterFace) unit 60. The CPU 54, the memory 56, the storage unit 58, and the I / F unit 60 are communicably connected to each other via an internal bus 62. In addition to the aforementioned seat operation mechanism 38, an occupant monitor device 48, an occupant restraint device 22, and a seat switch 50 are connected to the I / F unit 60, respectively.

[0023] The occupant monitor device 48 has a built-in camera and is provided on the ceiling portion of the vehicle interior so that the face of the occupant 12 can be photographed by the camera (see FIG. 1). The occupant monitor device 48 determines the presence or absence of the occupant 12 sitting on the vehicle seat 10 by performing predetermined image processing on the image photographed by the camera. Further, when it is determined that the occupant 12 is sitting on the vehicle seat 10, the occupant monitor device 48 detects whether the occupant 12 sitting on the vehicle seat 10 is asleep or awake. The occupant monitor device 48 is an example of the detection unit in the present disclosure.

[0024] The seat switch 50 is provided with a first switch for instructing the change in the angle of the seat back portion 30 and the direction of the change, and a second switch for instructing the change in the position of the vehicle seat 10 in the vehicle longitudinal direction and the direction of the change. Further, the seat switch 50 is provided with a third switch for instructing the change in the vertical position of the moving portion 28 of the seat cushion portion 24 in the vehicle vertical direction and the direction of the change, and a fourth switch for instructing the change in the angle of the ottoman portion 36 and the direction of the change.

[0025] When the first switch of the seat switch 50 is operated, the seat control ECU 52 drives the reclining motor 40 so that the angle of the seat back portion 30 changes in the change direction indicated by the operation of the first switch. Also, when the second switch of the seat switch 50 is operated, the seat control ECU 52 drives the front-rear slide motor 42 so that the vehicle seat 10 moves in the change direction indicated by the operation of the second switch.

[0026] Also, when the third switch of the seat switch 50 is operated, the seat control ECU 52 drives the lift motor 44 so that the moving portion 28 of the seat cushion portion 24 moves up and down in the change direction indicated by the operation of the third switch. Further, when the fourth switch of the seat switch 50 is operated, the seat control ECU 52 drives the ottoman motor 46 so that the angle of the ottoman portion 36 changes in the change direction indicated by the operation of the fourth switch.

[0027] Note that the seat control ECU 52 recognizes the angle of the seat back portion 30. The recognition of the angle of the seat back portion 30 may be performed, for example, by acquiring a signal from a sensor that detects the angle of the seat back portion 30 or the amount of rotation of the rotation axis of the reclining motor 40. Alternatively, if the reclining motor 40 is a pulse motor, it can also be realized by counting the number of pulses of the pulse signal output to the reclining motor 40.

[0028] Also, the seat control ECU 52 recognizes the position of the vehicle seat 10 in the vehicle longitudinal direction. The recognition of the position of the vehicle seat 10 in the vehicle longitudinal direction may be performed, for example, by acquiring a signal from a sensor that detects the position of the vehicle seat 10 in the vehicle longitudinal direction or the amount of rotation of the rotation axis of the front-rear slide motor 42. Alternatively, if the front-rear slide motor 42 is a pulse motor, it can also be realized by counting the number of pulses of the pulse signal output to the front-rear slide motor 42.

[0029] Also, the seat control ECU 52 recognizes the vertical position of the moving portion 28 of the seat cushion portion 24 in the vehicle. The recognition of the vertical position of the moving portion 28 of the seat cushion portion 24 in the vehicle may be performed, for example, by acquiring a signal from a sensor that detects the vertical position of the moving portion 28 of the seat cushion portion 24 in the vehicle or the amount of rotation of the rotation axis of the lifting motor 44. Alternatively, if the lifting motor 44 is a pulse motor, it can also be realized by counting the number of pulses of the pulse signal output to the lifting motor 44.

[0030] Furthermore, the seat control ECU 52 recognizes the angle of the ottoman portion 36. The recognition of the angle of the ottoman portion 36 may be performed, for example, by acquiring a signal from a sensor that detects the angle of the seat back portion 30 or the amount of rotation of the rotation axis of the ottoman motor 46. Alternatively, if the ottoman motor 46 is a pulse motor, it can also be realized by counting the number of pulses of the pulse signal output to the ottoman motor 46.

[0031] Further, a seat control program 64 is stored in a storage unit 58 of the seat control ECU 52. The seat control ECU 52 functions as a control unit 66 shown in FIG. 3 and performs seat control processing described later when the seat control program 64 is read from the storage unit 58 and expanded in the memory 56, and the seat control program 64 expanded in the memory 56 is executed by the CPU 54.

[0032] When the occupant monitor device 48 detects that the occupant 12 has fallen asleep, the control unit 66 displaces the vehicle seat 10 by the seat actuating mechanism 38 so that the distance between the occupant restraint device 22 and the occupant 12 becomes smaller. Further, when the occupant monitor device 48 subsequently detects that the occupant has woken up, the control unit 66 returns the position of the vehicle seat 10 to the position before falling asleep by the seat actuating mechanism 38. Note that the occupant monitor device 48, the seat actuating mechanism 38, and the seat control ECU 52 are examples of the vehicle seat control device according to the present disclosure.

[0033] Next, as an operation of the present embodiment, with reference to FIG. 4, seat control processing executed by the seat control ECU 52 (control unit 66) will be described.

[0034] In step 100 of the seat control processing, the control unit 66 acquires information indicating the result of determining the presence or absence of the occupant 12 sitting on the vehicle seat 10 from the occupant monitor device 48, and determines whether or not the occupant 12 is sitting on the vehicle seat 10 based on the acquired information. If the occupant 12 is not sitting on the vehicle seat 10, the determination in step 100 is negative and the seat control processing ends.

[0035] If the occupant 12 is sitting on the vehicle seat 10, the determination in step 100 is affirmative and the process proceeds to step 102. In step 102, the control unit 66 acquires information indicating the result of detecting whether the occupant 12 sitting on the vehicle seat 10 is asleep or awake from the occupant monitor device 48, and determines whether or not the occupant 12 is asleep based on the acquired information.

[0036] When it is detected by the occupant monitor device 48 that the occupant 12 sitting on the vehicle seat 10 is awake, the determination in step 102 is negated and the process proceeds to step 104. In step 104, the control unit 66 causes the storage unit 58 or the like to store the current position of the vehicle seat 10 (the angle of the seat back portion 30, the position of the vehicle seat 10 in the vehicle front-rear direction, the vertical position of the moving portion 28 of the seat cushion portion 24 in the vehicle vertical direction, and the angle of the ottoman portion 36). When the process of step 104 is performed, the seat control process ends.

[0037] When the occupant 12 sitting on the vehicle seat 10 and awake assumes a comfortable posture for the purpose of sleeping or the like, as shown in FIG. 5(A) as an example, it is common to recline the seat back portion 30 rearward of the vehicle and slide the seat cushion portion 24 rearward of the vehicle. As a result, the steering wheel 16 and the instrument panel 20 move away from the occupant 12, and the degree of freedom of the posture of the occupant 12 is improved.

[0038] However, in this state, the distances between the driver's seat airbag device 14 and the knee airbag device 18 and the occupant 12 increase, so it takes time for the restraint force to be exerted on the occupant 12 in the event of a frontal collision of the vehicle, resulting in insufficient restraint force or the possibility that appropriate occupant restraint cannot be achieved.

[0039] Therefore, when it is detected by the occupant monitor device 48 that the occupant 12 sitting on the vehicle seat 10 has fallen asleep, the determination in step 102 is affirmed and the process proceeds to step 106. Then, in step 106, the control unit 66 displaces the vehicle seat 10 to a predetermined sleep position. This predetermined sleep position is a position determined in advance such that the distance between the occupant restraint device 22 and the occupant 12 is reduced and the restraint by the occupant restraint device 22 is within an appropriate range, and the occupant 12 is positioned.

[0040] Specifically, as also shown in FIG. 5(B) by way of example, the position of the vehicle seat 10 in the vehicle longitudinal direction is at or near the front end of its movement range, and the position of the moving part 28 of the seat cushion part 24 in the vehicle vertical direction is at or near the upper end of its movement range (see also arrow J shown in FIG. 5(B)). Further, the predetermined sleep position is a position where the angle of the ottoman part 36 is an angle that grounds the sole of the occupant 12 near the toe board 21 (see also arrow K shown in FIG. 5(B)).

[0041] Thus, when the occupant 12 sitting on the vehicle seat 10 is asleep, by displacing the vehicle seat 10 to the above-described predetermined sleep position, the timing of occupant restraint during a vehicle frontal collision can be advanced, and the safety during a vehicle frontal collision while the occupant is asleep can be improved. Also, although the degree of freedom of the posture of the occupant 12 will decrease as the vehicle seat 10 is displaced to the predetermined sleep position, since the timing of displacing the vehicle seat 10 is after the occupant 12 has fallen asleep, it is possible to suppress the displacement of the vehicle seat 10 from giving a sense of discomfort to the occupant 12.

[0042] When the process of step 106 is performed, the process proceeds to step 108. In step 108, the control unit 66 acquires information indicating the result of detecting whether the occupant 12 is asleep or awake from the occupant monitor device 48, and determines whether the occupant 12 is awake based on the acquired information. If the determination in step 108 is negative, the process proceeds to step 110. In step 110, the control unit 66 maintains the vehicle seat 10 in the sleep position and returns to step 106. Thereby, while the occupant 12 is asleep, the vehicle seat 10 is maintained in the sleep position.

[0043] Also, when the sleeping occupant 12 wakes up, the determination in step 108 is affirmed and the process proceeds to step 112. In step 112, the control unit 66 reads out the position of the vehicle seat 10 stored in the storage unit 58 etc. in the previous step 104, and displaces the vehicle seat 10 to the read-out position. Thereby, it is possible to ensure the degree of freedom of the posture of the occupant 12 during the period when the occupant 12 is awake.

[0044] As described above, the occupant monitoring device 48 detects the sleeping and waking of the occupant 12 sitting on the vehicle seat 10 provided with the occupant restraint device 22 on the front side of the vehicle. The seat actuation mechanism 38 displaces the vehicle seat 10 by the driving force of the motors 40, 42, 44, 46. When the seat control ECU 52 (control unit 66) detects that the occupant 12 is sleeping by the occupant monitoring device 48, the seat actuation mechanism 38 displaces the vehicle seat 10 so that the distance between the occupant restraint device 22 and the occupant 12 becomes smaller. Further, when the seat control ECU 52 (control unit 66) subsequently detects that the occupant 12 is awake by the occupant monitoring device 48, the seat actuation mechanism 38 returns the position of the vehicle seat 10 to the position before sleep. Thereby, it is possible to improve the safety at the time of a vehicle frontal collision during the period when the occupant 12 is sleeping without impairing the degree of freedom of the posture during the period when the occupant 12 is awake.

[0045] In the above embodiment, the mode of returning the vehicle seat 10 to the position before sleep when the sleeping occupant 12 wakes up has been described, but the present disclosure is not limited to this. For example, the vehicle seat 10 may be displaced to a position according to an input via the seat switch 50 by the waking occupant 12.

[0046] In the above-described embodiment, as an example of displacing the vehicle seat 10 to a predetermined sleep position, the case where the position of the vehicle seat 10 in the vehicle front-rear direction, the position of the moving part 28 of the seat cushion part 24 in the vehicle up-down direction, and the angle of the ottoman part 36 are each changed has been described. However, the present disclosure is not limited to this. For example, the present disclosure is also applicable to a seat not provided with the ottoman part 36. In this case, when displacing the vehicle seat 10 to a predetermined sleep position, changing the angle of the ottoman part 36 is omitted. Further, when displacing the vehicle seat 10 to a predetermined sleep position, for example, the angle of the seat back part 30 may also be changed.

[0047] In the above-described embodiment, the mode of displacing the vehicle seat 10 to a predetermined sleep position when the occupant 12 is asleep has been described. However, the present disclosure is not limited to this, and an appropriate sleep position may be determined for each physique of the occupant 12, the physique of the occupant 12 may also be detected by the occupant monitoring device 48, and the vehicle seat 10 may be displaced to the sleep position corresponding to the detected physique of the occupant 12.

[0048] In the above, the mode in which the seat control program 64 is pre-stored (installed) in the storage unit 58 has been described. However, the seat control program can also be provided in a form recorded on a non-temporary recording medium such as an HDD, an SSD, or a DVD.

Explanation of Reference Numerals

[0049] 10 Vehicle seat 12 Occupant 14 Driver's airbag device 16 Steering wheel 18 Knee airbag device 20 Instrument panel 22 Occupant restraint device 24 Seat cushion part 30 Seat back part 32 Headrest part 34 Seat rail 36 Ultraman part 38 Sheet operating mechanism 48 Occupant monitor device (detection unit) 52 Seat control ECU 66 Control unit

Claims

【Claim 1】 An occupant restraint device that deploys an airbag to the rear side of the vehicle during a frontal collision of the vehicle, A detection unit that detects the sleep and awakening of an occupant sitting on a seat provided on the front side of the vehicle, the occupant restraint device being provided on the front side of the vehicle; A seat actuation mechanism that displaces the seat by the driving force of a motor; When the detection unit detects that the occupant is asleep, the seat actuation mechanism displaces the seat at least forward of the vehicle from the position before sleep, and then when the detection unit detects that the occupant is awake, the seat actuation mechanism returns the position of the seat to the position before sleep or displaces the seat to a position according to the input of the occupant. A control unit; A vehicle seat control device including the above.

Images