Car sickness prevention device, method, program, and vehicle seat

Abstract

To obtain with high accuracy a condition for determining whether an occupant seated on a seat in a vehicle may get carsick.SOLUTION: A seat ECU obtains acceleration (a) in a longitudinal direction of a vehicle; performs arithmetic processing based on a following formula (1): θ>tan-1(a / g) (1), where inclination angles of a head part and a trunk part of an occupant seated on a seat in the vehicle are defined as θ and gravitational acceleration is defined as g; obtains an inclination angle θ0 at which an occupant can be suppressed from getting carsick, from the acceleration (a) in the longitudinal direction of the vehicle; and performs guide about adjustment of an angle of the seat by the occupant so that inclination angles θhead and θupper body of the head part and of the trunk part of the occupant seated on the seat in the vehicle respectively are equal to or greater than the inclination angle θ0. This can suppress the occupant seated on a seat main body 12 in the vehicle from getting carsick.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a car sickness prevention device, a car sickness prevention method, a car sickness prevention program, and a vehicle seat. [Background technology]

[0002] Patent document 1 describes a technology that detects driving conditions such as whether a vehicle is turning right or left, accelerating or decelerating, and the vehicle's acceleration in the up and down, left and right, and front and rear directions, and if the acceleration is above a reference value, displays an image with a message video superimposed on content video from a television, VTR, DVD, game, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-20539 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, people sense acceleration with otoliths in the head, and therefore, displacement of a person's head when acceleration is applied causes car sickness. The inventors of the present application have discovered that whether a person's head is displaced when acceleration is applied depends on the person's posture when acceleration is applied, more specifically, the tilt angle of the person's head and trunk (thorax). In contrast, Patent Document 1 determines that a case in which acceleration equal to or greater than a reference value is applied is a case in which car sickness is likely to occur, without considering the posture of the occupant when acceleration is applied, and there is room for improvement in the accuracy of determining whether car sickness will occur.

[0005] The present disclosure has been made in consideration of the above facts, and aims to provide a car sickness prevention device, a car sickness prevention method, a car sickness prevention program, and a vehicle seat that can accurately obtain conditions for determining whether or not a passenger sitting in a vehicle seat will become car sick. [Means for solving the problem]

[0006] The car sickness prevention device according to the first aspect includes an acquisition unit that acquires a longitudinal acceleration a of a vehicle or an inclination angle θ of the head and trunk of an occupant seated in a seat of the vehicle; θ>tan -1 (a / g) …(1) The device includes a calculation unit that performs calculation processing of the above equation (1) when the gravitational acceleration is g, and obtains the tilt angle θ at which car sickness is suppressed from the acceleration a obtained by the acquisition unit, or obtains the acceleration a at which car sickness is suppressed from the tilt angle θ obtained by the acquisition unit.

[0007] The inventors of the present application have obtained the above formula (1) as a condition for preventing displacement of the head of an occupant seated in a vehicle seat with the head and trunk tilted at an angle θ when acceleration a in the longitudinal direction of the vehicle is applied (details will be described later). The first mode acquires the acceleration a in the longitudinal direction of the vehicle, or the tilt angle θ of the head and trunk of the occupant seated in the vehicle seat. The first mode also performs arithmetic processing of the above formula (1) to obtain the tilt angle θ at which car sickness is suppressed from the acceleration a, or the acceleration a at which car sickness is suppressed from the tilt angle θ. Therefore, according to the first mode, it is possible to accurately obtain the condition for determining whether or not an occupant seated in a vehicle seat will experience car sickness (the tilt angle θ at which car sickness is suppressed, or the acceleration a at which car sickness is suppressed).

[0008] In a second aspect, in the first aspect, the acquisition unit acquires, as the acceleration a, an acceleration component of the acceleration in a longitudinal direction of the vehicle that is equal to or lower than a predetermined frequency.

[0009] Car sickness is mainly caused by low-frequency displacement of the human head. In the second mode, acceleration a is obtained by acquiring acceleration components of the vehicle's longitudinal acceleration that are equal to or lower than a predetermined frequency, so that acceleration a can have a higher correlation with the occupant's car sickness.

[0010] In a third aspect, in the first or second aspect, the acquisition unit acquires, as the acceleration a, an acceleration component of the acceleration in a longitudinal direction of the vehicle, the acceleration component having a duration of at least a predetermined time.

[0011] The inventors of the present application have confirmed through experiments that whether or not a person's head is displaced when acceleration is applied depends on the duration of the acceleration, and that the longer the duration, the more likely the head is to be displaced and the more likely it is that car sickness will occur. In the third aspect, the acceleration a is obtained by acquiring, as the acceleration a, the acceleration component of the acceleration in the longitudinal direction of the vehicle whose duration of acceleration is equal to or longer than a predetermined time, so that a value that has a higher correlation with car sickness of the occupant can be obtained.

[0012] A fourth aspect is any of the first to third aspects, further including a first estimation unit that estimates the inclination angle θ of an occupant sitting on the seat from the angle of the seat, and the calculation unit performs processing to determine whether the inclination angle θ estimated by the first estimation unit satisfies equation (1) in which the acceleration a acquired by the acquisition unit is substituted.

[0013] In the fourth aspect, the inclination angle θ of the occupant seated in the seat is estimated from the seat angle, so the device configuration can be simplified compared to aspects in which the inclination angle θ is detected by a sensor, etc. Then, it can be determined by simple processing whether the estimated inclination angle θ is within the range of inclination angles θ in which car sickness is suppressed.

[0014] A fifth aspect is any of the first to fourth aspects, further including a guide unit that guides the occupant in adjusting the angle of the seat so that the inclination angles of the head and trunk of the occupant seated in the seat of the vehicle are each equal to or greater than the inclination angle θ at which car sickness is suppressed, obtained by the calculation unit.

[0015] In the fifth aspect, when the occupant adjusts the seat angle, the seat angle is guided to an angle that suppresses car sickness, thereby suppressing car sickness in occupants seated in the vehicle seat.

[0016] A sixth aspect is any of the first to fourth aspects, further including a control unit that controls the angle adjustment of the seat by the seat angle adjustment device so that the inclination angles of the head and trunk of an occupant seated in the vehicle seat are each equal to or greater than the inclination angle θ obtained by the calculation unit at which car sickness is suppressed.

[0017] In the sixth aspect, when adjusting the seat angle using the seat angle adjustment device, the seat angle is controlled to an angle that suppresses car sickness, thereby preventing car sickness from occurring in occupants sitting in the vehicle seat.

[0018] The seventh aspect is the first aspect, further including a second estimation unit that acquires the angle of the seat and estimates the inclination angle θ of an occupant sitting on the seat from the acquired seat angle, and the acquisition unit acquires the inclination angle θ of the occupant sitting on the seat from the second estimation unit.

[0019] In the seventh aspect, the inclination angle θ of the occupant seated in the seat is estimated from the angle of the seat, so the device configuration can be simplified compared to aspects in which the inclination angle θ is detected by a sensor.

[0020] An eighth aspect is the fourth or seventh aspect, further including a memory unit that stores the relationship between the angle of the seat and the inclination angle θ of the head and trunk of an occupant sitting on the seat, and the first estimation unit or the second estimation unit estimates the inclination angle θ of the occupant sitting on the seat from the angle of the seat based on the information stored in the memory unit.

[0021] In the eighth aspect, the inclination angle θ is estimated based on the relationship between the seat angle stored in the memory unit and the inclination angle θ of the head and trunk of the occupant seated in the seat, which simplifies processing compared to when the above relationship is defined in advance using an arithmetic formula or the like.

[0022] A ninth aspect is any of the first, seventh, and eighth aspects, further including a first notification unit that notifies when the longitudinal acceleration of the vehicle being driven by the occupant is greater than the acceleration a at which car sickness is suppressed, obtained by the calculation unit.

[0023] In the ninth aspect, when a vehicle is being driven by a vehicle occupant, a notification is given when the longitudinal acceleration of the vehicle reaches or exceeds the acceleration a at which car sickness is suppressed, and the vehicle is induced to be driven so that the longitudinal acceleration of the vehicle is less than the acceleration a. This makes it possible to suppress car sickness in a vehicle occupant seated in the seat.

[0024] A tenth aspect is any of the first, seventh and eighth aspects, further including a second notification unit that notifies the driving route selection device of the acceleration a at which car sickness is suppressed, obtained by the calculation unit, so that a driving route is selected as the driving route for the vehicle on which the longitudinal acceleration of the vehicle while traveling is equal to or less than the acceleration a at which car sickness is suppressed.

[0025] In the tenth aspect, the acceleration a at which car sickness is suppressed is notified to the driving route selection device so that a driving route is selected in which the vehicle's longitudinal acceleration while driving is less than the acceleration a, thereby suppressing car sickness among passengers seated in the vehicle seats.

[0026] A vehicle seat according to an eleventh aspect includes a seat body on which a vehicle occupant sits, and the car sickness prevention device according to any one of the first to tenth aspects.

[0027] According to the eleventh aspect, similarly to the first aspect, it is possible to obtain with high accuracy the conditions for determining whether or not an occupant seated in a vehicle seat will suffer from car sickness.

[0028] A car sickness suppression method according to a twelfth aspect includes acquiring a longitudinal acceleration a of a vehicle or an inclination angle θ of a head and a trunk of an occupant seated in a seat of the vehicle, θ>tan-1 (a / g) …(1) When the gravitational acceleration is g, the computer performs the calculation process of the above equation (1) to obtain the tilt angle θ at which car sickness is suppressed from the acquired acceleration a, or to obtain the acceleration a at which car sickness is suppressed from the acquired tilt angle θ.

[0029] According to the twelfth aspect, similarly to the first aspect, it is possible to obtain with high accuracy the conditions for determining whether or not an occupant seated in a vehicle seat will suffer from car sickness.

[0030] A car sickness prevention program according to a thirteenth aspect of the present invention includes causing a computer to acquire a longitudinal acceleration a of a vehicle or an inclination angle θ of a head and a trunk of an occupant seated in a seat of the vehicle, θ>tan -1 (a / g) …(1) When the gravitational acceleration is g, the calculation processing of the above equation (1) is performed to obtain the tilt angle θ at which car sickness is suppressed from the acquired acceleration a, or to execute processing that includes obtaining the acceleration a at which car sickness is suppressed from the acquired tilt angle θ.

[0031] According to the thirteenth aspect, similarly to the first aspect, it is possible to obtain with high accuracy the conditions for determining whether or not an occupant seated in a vehicle seat will suffer from car sickness. [Effects of the Invention]

[0032] The present disclosure has an effect of being able to accurately obtain conditions for determining whether or not an occupant seated in a vehicle seat will suffer from car sickness. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a side view of a vehicle seat according to an embodiment; [Figure 2] 2 is a block diagram showing a schematic configuration of a seat ECU and its periphery according to the first embodiment. FIG. [Figure 3]FIG. 2 is a functional block diagram of a seat ECU according to the first embodiment. [Figure 4] 10 is a diagram illustrating an example of a conversion table. [Figure 5A] FIG. 2 is an explanatory diagram for explaining the function of formula (1) in the present disclosure. [Figure 5B] FIG. 2 is an explanatory diagram for explaining the function of formula (1) in the present disclosure. [Figure 6] FIG. 2 is an explanatory diagram for explaining the function of formula (1) in the present disclosure. [Figure 7] 3 is a flowchart showing a car sickness prevention process 1 according to the first embodiment. [Figure 8] 10A and 10B are conceptual diagrams showing an example of the posture of an occupant before and after adjusting the seat angle. [Figure 9] FIG. 10 is a block diagram showing a schematic configuration of a seat ECU and its periphery according to a second embodiment. [Figure 10] FIG. 10 is a functional block diagram of a seat ECU according to a second embodiment. [Figure 11] 10 is a flowchart showing a car sickness prevention process 2 according to a second embodiment. [Figure 12] FIG. 10 is a functional block diagram of a seat ECU according to a third embodiment. [Figure 13] 10 is a flowchart showing a car sickness prevention process 3 according to the third embodiment. [Figure 14] FIG. 10 is a functional block diagram of a seat ECU according to a fourth embodiment. [Figure 15] 10 is a flowchart showing a car sickness prevention process 4 according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, an example of an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0035] [First embodiment] The vehicle seat 10 shown in Fig. 1 includes a seat body 12. In this embodiment, the seat body 12 is provided in a passenger seat in the passenger compartment of the vehicle and is seated by a passenger 20 in the passenger seat of the vehicle. The seat body 12 includes a seat cushion portion 14, a seat back portion 16, and a headrest portion 18.

[0036] The seatback 16 has a lower end in the vehicle vertical direction attached to the rear end in the vehicle front-rear direction of the seat cushion 14 via a reclining mechanism 22, and is rotatable around an axis along the vehicle width direction (in the direction of arrow A in Figure 1) relative to the seat cushion 14. The reclining mechanism 22 includes a reclining angle φ1 sensor 24 (see Figure 2) that detects the angle (reclining angle φ1) of the seatback 16 relative to the seat cushion 14.

[0037] Furthermore, a seat-back tilting mechanism 26 that connects the upper and lower parts of the seatback 16 is disposed in the middle of the seatback 16 in the vertical direction of the vehicle. The upper part of the seatback 16 is rotatable relative to the lower part of the seatback 16 about an axis along the vehicle width direction (in the direction of arrow B in Figure 1). The seat-back tilting mechanism 26 includes a seat-back tilting angle φ2 sensor 28 (see Figure 2) that detects the angle (seat-back tilting angle φ2) of the upper part of the seatback 16 relative to the lower part of the seatback 16.

[0038] The headrest 18 is attached to the upper end of the seatback 16 in the vehicle up-down direction so as to be slidable along the length of the seatback 16. A headrest mechanism 30 is built into the headrest 18, and the headrest 18 is rotatable around an axis along the vehicle width direction (in the direction of arrow C in Figure 1) relative to the upper part of the seatback 16. The headrest mechanism 30 includes a headrest angle φ3 sensor 31 (see Figure 2) that detects the angle of the headrest 18 (headrest angle φ3) relative to the upper part of the seatback 16.

[0039] The vehicle seat 10 also includes a seat ECU (Electronic Control Unit) 32, which is housed in the seat cushion portion 14. As shown in Fig. 2, the seat ECU 32 includes a CPU (Central Processing Unit) 34, a memory 36 such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and a non-volatile storage unit 38 such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The CPU 34, the memory 36, and the storage unit 38 are connected to each other via an internal bus 40 so as to be able to communicate with each other.

[0040] The seat ECU 32 is connected to the reclining angle φ1 sensor 24 of the reclining mechanism 22, the folding angle φ2 sensor 28 of the folding mechanism 26, and the headrest angle φ3 sensor 31 (see FIG. 2) of the headrest mechanism 30. The seat ECU 32 constantly monitors the outputs of the reclining angle φ1 sensor 24, the folding angle φ2 sensor 28, and the headrest angle φ3 sensor 31, thereby constantly monitoring the reclining angle φ1, the folding angle φ2, and the headrest angle φ3.

[0041] The seat ECU 32 is also connected to an audio output unit 42 including a speaker provided in the vehicle cabin, and to a system bus 72 of an in-vehicle system 70 provided in the vehicle. An acceleration sensor 74 that detects acceleration of the vehicle in at least the longitudinal direction, and a vehicle speed sensor 76 that detects the vehicle speed are connected to the system bus 72 of the in-vehicle system 70.

[0042] The storage unit 38 of the seat ECU 32 stores a car sickness prevention program 44 and a conversion table 46. In the first embodiment, the car sickness prevention program 44 according to the first embodiment is read from the storage unit 38 and loaded into the memory 36, and the car sickness prevention program 44 loaded into the memory 36 is executed by the CPU 34, thereby causing the seat ECU 32 to function as each of the functional units shown in Fig. 3. That is, in the first embodiment, the seat ECU 32 functions as an acceleration acquisition unit 50, a first estimation unit 52, an inclination angle calculation unit 54, and a seat angle adjustment guidance unit 56. Furthermore, the storage unit 38 of the seat ECU 32, which stores the conversion table 46, functions as the storage unit 58 shown in Fig. 3.

[0043] The acceleration acquisition unit 50 acquires the acceleration a in the front-to-rear direction of the vehicle. The acceleration acquisition unit 50 is an example of an acquisition unit in the present disclosure. The first estimation unit 52 estimates the head tilt angle θhead and the trunk tilt angle θupperbody of the occupant seated in the seat main body 12 from the angle of the seat main body 12 (reclining angle φ1, center-bending angle φ2, and headrest angle φ3).

[0044] The estimation of the inclination angles θhead and θupperbody by the first estimating unit 52 is performed based on a conversion table 46 stored in the storage unit 58. As shown in Fig. 4, the conversion table 46 stores the angles φ1, φ2, and φ3 of the seat main body 12 in association with the inclination angles θhead and θupperbody of the head and trunk of an occupant seated in the seat main body 12 when the seat main body 12 is adjusted to the angles φ1, φ2, and φ3.

[0045] The tilt angle calculation unit 54 θ>tan -1 (a / g) …(1) When the acceleration of gravity is g, the tilt angle θ0 at which car sickness is suppressed is obtained from the acceleration a in the longitudinal direction of the vehicle acquired by the acceleration acquisition unit 50 by performing the calculation process of the above equation (1). Furthermore, the tilt angle calculation unit 54 performs a process to determine whether the tilt angles θhead and θupperbody estimated by the first estimation unit 52 satisfy the above equation (1) into which the acceleration a acquired by the acceleration acquisition unit 50 is substituted. The tilt angle calculation unit 54 is an example of a calculation unit in the present disclosure.

[0046] The seat angle adjustment guide unit 56 guides the occupant to adjust the angle of the seat body 12 so that the inclination angles θhead and θupperbody of the head and trunk of the occupant seated in the vehicle seat body 12 are equal to or greater than the inclination angle θ0 at which car sickness is suppressed, which is obtained by the inclination angle calculation unit 54. The seat angle adjustment guide unit 56 is an example of a guide unit in the present disclosure, and the seat ECU 32 is an example of a car sickness determination device in the present disclosure.

[0047] Next, as an operation of the first embodiment, first, equation (1) in the present disclosure will be described. Consider a case where acceleration in the deceleration direction is applied to the vehicle while an occupant is seated in the seat main body 12. Here, as shown in Fig. 5A, when the occupant's head moves away from the headrest portion 18 and displaces toward the front of the vehicle, a resultant force obtained by adding together a component of inertial force (acceleration in the deceleration direction) and a component of gravitational acceleration acts on the occupant's head in the front-to-rear direction of the head, generating a larger acceleration (resultant force of each component force = large).

[0048] 5B, if the occupant's head does not move away from headrest 18 when acceleration in the deceleration direction is applied to the vehicle, the acceleration acting on the occupant's head in the front-to-rear direction, which is a cause of car sickness, is suppressed (resultant force of each component force = small), and car sickness can be suppressed. Whether or not the occupant's head moves away from headrest 18 when acceleration in the deceleration direction is applied to the vehicle depends on the occupant's posture when the acceleration is applied, more specifically, the tilt angle θ of the occupant's head and trunk.

[0049] As shown in Fig. 6, the front-rear component forces of the head with respect to the inertial force and gravity are F1 and F2, respectively. When the inertial component force F1 is smaller than the gravitational component force F2, it is considered that the head will not separate from the headrest portion 18, and therefore the following formula (0) holds true. F1 <F2 …(0) By rewriting equation (0) with a as the inertial force (acceleration) in the deceleration direction, g as the gravitational acceleration, m as the mass of the head, and θ as the tilt angle of the occupant's head, the aforementioned equation (1) can be obtained by solving this. m·a·cosθ <m·g·sinθ (a / g) <tanθ

[0050] Although Fig. 6 shows the head of the occupant, the same concept applies to the trunk, and the tilt angle θ in equation (1) also holds true for the tilt angle of the trunk of the occupant. By adjusting the head and trunk angles according to equation (1), the occupant's head is prevented from separating from the headrest 18 when an inertial force (acceleration) in the deceleration direction occurs. The tilt angle θ in equation (1) is the angle of tilt from the vertical direction toward the rear of the vehicle (see also Fig. 8).

[0051] Next, with reference to FIG. 7, a car sickness prevention process 1 that is executed by the seat ECU 32 according to the first embodiment while the ignition switch of the vehicle is on will be described.

[0052] In step 150 of the car sickness prevention process 1, the acceleration acquisition unit 50 acquires acceleration data for a certain period of time from the acceleration sensor 74. Note that instead of acquiring acceleration data from the acceleration sensor 74, vehicle speed data for a certain period of time may be acquired from the vehicle speed sensor 76, and the acceleration data may be calculated by differentiating the acquired vehicle speed data. Furthermore, the certain period of time in step 150 is, for example, a period of time equal to or longer than the duration of acceleration, which will be described later.

[0053] In step 152, the acceleration acquisition unit 50 extracts acceleration components that are equal to or lower than a predetermined frequency and whose acceleration duration is equal to or longer than a predetermined time from the acceleration data acquired in step 150. Note that the predetermined frequency can be, for example, 2 Hz, and the predetermined time can be, for example, 0.2 to 0.6 seconds. This makes it possible to obtain acceleration components that are more highly correlated with car sickness in occupants.

[0054] Note that the appropriate value for the duration of acceleration differs depending on the values ​​of the tilt angles θhead and θupperbody of the occupant's head and trunk. Therefore, the present disclosure is not limited to setting the threshold (predetermined value) for the duration of acceleration to a constant value, and the relationship between the tilt angles θhead and θupperbody of the occupant's head and trunk and the duration of acceleration may be stored in the form of a function or a table, and the duration of acceleration may be changed depending on the tilt angles θhead and θupperbody of the occupant's head and trunk.

[0055] In step 154, the acceleration acquisition unit 50 acquires the maximum value (=acceleration a) of the acceleration components extracted in step 152. In step 156, the tilt angle calculation unit 54 substitutes the acceleration a acquired in step 154 ​​into equation (1) and performs calculation processing of equation (1) to obtain the tilt angle θ0 at which car sickness is suppressed. In step 158, the first estimation unit 52 acquires the current reclining angle φ1, center-folding angle φ2, and headrest angle φ3 of the seat main body 12, which are constantly kept track of by the seat ECU 32.

[0056] In step 160, the first estimation unit 52 estimates the current tilt angle θhead of the occupant's head and the current tilt angle θupperbody of the trunk from the current angles φ1, φ2, and φ3 of the seat main body 12 acquired in step 158. The current tilt angles θhead and θupperbody can be estimated by reading out the tilt angles θhead and θupperbody associated with the current angles φ1, φ2, and φ3 of the seat main body 12 from the conversion table 46 stored in the memory unit 58.

[0057] In step 162, the tilt angle calculation unit 54 determines whether the current tilt angle θhead of the occupant's head is greater than the tilt angle θ0 at which car sickness is suppressed. If the determination in step 162 is positive, the process proceeds to step 164. In step 164, the tilt angle calculation unit 54 determines whether the current tilt angle θupperbody of the occupant's trunk is greater than the tilt angle θ0 at which car sickness is suppressed.

[0058] As described above, the reason why it is determined whether the tilt angle θhead of the occupant's head and the tilt angle θupperbody of the trunk are greater than the tilt angle θ0 at which car sickness is suppressed is as follows: That is, when only the occupant's trunk is greater than the tilt angle θ0 (when formula (1) is satisfied), there is a high possibility that the occupant's head will be separated from the headrest 18 when acceleration a is applied. Also, when only the occupant's head is greater than the tilt angle θ0 (when formula (1) is satisfied), there is a high possibility that the occupant's trunk will be separated from the seat back 16 when acceleration a is applied, and as a result, the occupant's head will be pulled by the trunk and will also be separated from the headrest 18.

[0059] If the determinations in step 162 and step 164 are both positive, it can be determined that the occupant's head will not separate from the headrest portion 18 even when acceleration a is applied, and the process returns to step 150. In this case, the angles φ1, φ2, and φ3 of the seat main body 12 are not adjusted. On the other hand, if the determinations in step 162 or step 164 are negative, there is a high possibility that the occupant's head will separate from the headrest portion 18 when acceleration a is applied, and the process proceeds to step 166.

[0060] In step 166, the seat angle adjustment guide unit 56 outputs a sound from the audio output unit 42 to guide the occupant in adjusting the seat angle so that the tilt angle θhead of the occupant's head becomes larger than the tilt angle θ0 and the tilt angle θupperbody of the occupant's trunk becomes larger than the tilt angle θ0.

[0061] As an example, the seat angle adjustment guide unit 56 refers to the conversion table 46 stored in the memory unit 58, and extracts, as the target angle, a combination of angles φ1, φ2, and φ3 of the seat main body 12 when the tilt angles θhead and θupperbody are equal to or greater than the tilt angle θ0. Note that if multiple combinations of angles φ1, φ2, and φ3 are extracted, it is preferable to select, as the target angle, a combination that minimizes the difference from the current angles φ1, φ2, and φ3 of the seat main body 12.

[0062] Next, based on the target angle, seat angle adjustment guide unit 56 outputs a voice message such as, "Please increase the reclining angle (or the seat back tilt angle or the headrest angle) to prevent car sickness," while the vehicle is stopped, prompting the occupant to adjust reclining angle φ1 via reclining mechanism 22, or adjust seat back tilt angle φ2 via seat back tilt mechanism 26, or adjust headrest angle φ3 via headrest mechanism 30.

[0063] Once the occupant has performed the angle adjustment operation, the process returns to step 158, and in steps 158 to 164, it is determined again whether the occupant's tilt angles θhead and θupperbody are greater than the tilt angle θ0 in the seat body 12 that has undergone the angle adjustment operation. If the determination in step 162 or step 164 is negative, the process in step 166 is performed again, and the occupant performs the angle adjustment operation again. On the other hand, if the determination in step 162 or step 164 is positive, the seat angle adjustment guide unit 56 notifies the occupant that the angle adjustment operation is complete by outputting a voice message such as "Seat adjustment is complete."

[0064] By the above-described car sickness prevention process 1, even if the occupant's tilt angles θhead and θupperbody are smaller than the tilt angle θ0 in the seat main body 12 before the process is executed, as shown by "before adjustment" in Fig. 8, the occupant's tilt angles θhead and θupperbody are adjusted to be larger than the tilt angle θ0, as shown by "after adjustment" in Fig. 8. Therefore, when acceleration a is applied, the occupant's head is prevented from moving away from the headrest portion 18, and the occurrence of car sickness can be prevented.

[0065] Furthermore, since the occupant's head is prevented from moving away from the headrest 18, the occupant's posture stability is improved without the annoyance of the head moving away from and back (hitting) the headrest 18 each time the vehicle decelerates. This also has the secondary effect of making it easier for the occupant to view the in-vehicle display, etc.

[0066] As described above, in the first embodiment, the seat ECU 32 has the acceleration acquisition unit 50 acquire the acceleration a in the longitudinal direction of the vehicle. The tilt angle calculation unit 54 performs calculation processing of the above-mentioned equation (1) to obtain the tilt angle θ0 at which car sickness of the head and trunk of the occupant is suppressed from occurring, from the acceleration a in the longitudinal direction of the vehicle acquired by the acceleration acquisition unit 50. This makes it possible to accurately obtain the condition (tilt angle θ at which car sickness is suppressed) for determining whether or not an occupant seated in the seat main body 12 of the vehicle will experience car sickness.

[0067] In the first embodiment, the acceleration acquiring unit 50 acquires, as the acceleration a, an acceleration component of the vehicle's longitudinal acceleration that is equal to or lower than a predetermined frequency. This makes it possible to obtain, as the acceleration a, a value that has a higher correlation with the occupant's car sickness, thereby improving the accuracy of the conditions for determining whether the occupant will suffer from car sickness.

[0068] In the first embodiment, the acceleration acquisition unit 50 acquires, as the acceleration a, an acceleration component of the vehicle's longitudinal acceleration that lasts for a predetermined time or longer. This makes it possible to obtain, as the acceleration a, a value that has a higher correlation with the occupant's car sickness, thereby improving the accuracy of the conditions for determining whether the occupant will suffer from car sickness.

[0069] In the first embodiment, the first estimation unit 52 estimates the inclination angles θhead and θupperbody of the head and trunk of an occupant seated on the seat main body 12 from the angles φ1, φ2, and φ3 of the seat main body 12. The inclination angle calculation unit 54 determines whether the inclination angles θhead and θupperbody estimated by the first estimation unit 52 satisfy the above-described formula (1) into which the acceleration a acquired by the acceleration acquisition unit 50 is substituted. This simplifies the device configuration compared to an embodiment in which the inclination angles θhead and θupperbody are detected by a sensor. Then, it is possible to determine, by simple processing, whether the estimated inclination angles θhead and θupperbody are within the range of the inclination angle θ0 at which car sickness is suppressed.

[0070] Furthermore, in the first embodiment, the storage unit 58 stores, as a conversion table 46, the relationship between the angles φ1, φ2, and φ3 of the seat main body 12 and the inclination angles θhead and θupperbody of the head and trunk of an occupant seated in the seat main body 12. Furthermore, the first estimating unit 52 estimates the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 from the angles φ1, φ2, and φ3 of the seat main body 12 based on the conversion table 46 stored in the storage unit 58. This simplifies processing compared to when the relationship between the angles φ1, φ2, and φ3 of the seat main body 12 and the inclination angles θhead and θupperbody of the head and trunk of an occupant seated in the seat main body 12 is defined in advance using an arithmetic expression or the like.

[0071] Furthermore, in the first embodiment, the seat angle adjustment guide unit 56 guides the occupant to adjust the angle of the seat body 12 so that the inclination angles θhead and θupperbody of the occupant seated in the vehicle seat body 12 are each equal to or greater than the inclination angle θ0 at which car sickness is suppressed, which is obtained by the inclination angle calculation unit 54. This makes it possible to suppress car sickness in the occupant seated in the vehicle seat body 12.

[0072] In the first embodiment, the seat angle adjustment guide unit 56 provides audio guidance to the occupant when adjusting the angle of the seat main body 12. However, the present disclosure is not limited to this, and the seat angle adjustment guide unit 56 may provide guidance when adjusting the angle of the seat main body 12 by using an image displayed on an in-vehicle display instead of audio.

[0073] Second Embodiment Next, a second embodiment of the present disclosure will be described. Note that the same parts as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0074] 9, the seat body 12 is provided with a reclining angle adjustment device 78 in place of the reclining mechanism 22. The reclining angle adjustment device 78 includes a reclining angle φ1 sensor 24 and a motor 80, and the driving force of the motor 80 rotates the seat back portion 16 relative to the seat cushion portion 14 around an axis along the vehicle width direction (in the direction of arrow A in FIG. 1).

[0075] Furthermore, the seat body 12 is provided with a seat-back angle adjustment device 82 instead of the seat-back tilting mechanism 26. The seat-back angle adjustment device 82 includes a seat-back angle φ2 sensor 28 and a motor 84, and the driving force of the motor 84 causes the upper part of the seat back 16 to rotate relative to the lower part of the seat back 16 around an axis along the vehicle width direction (in the direction of arrow B in Figure 1).

[0076] The seat body 12 is also provided with a headrest angle adjustment device 86 instead of the headrest mechanism 30. The headrest angle adjustment device 86 includes a headrest angle φ3 sensor 31 and a motor 88, and the driving force of the motor 88 causes the headrest portion 18 to rotate around an axis along the vehicle width direction relative to the upper part of the seatback portion 16 (in the direction of arrow C in Figure 1).

[0077] A driving route selection device 92 that selects a route along which the vehicle will travel is also connected to the system bus 72 of the in-vehicle system 70. A typical example of the driving route selection device 92 is a car navigation device that selects a driving route based on the current position of the vehicle and a destination set by the occupant, and performs processing to guide the vehicle along the selected driving route.

[0078] Meanwhile, an acceleration DB (DataBase) 90 is stored in the memory unit 38 (memory unit 58: see FIG. 10) of the seat ECU 32. The acceleration DB 90 stores acceleration data detected by the acceleration sensor 74 while the vehicle was traveling on roads that the vehicle had previously traveled, in association with information identifying the roads that had been traveled.

[0079] In the second embodiment, the car sickness prevention program 44 according to the second embodiment is read from the storage unit 38 and loaded into the memory 36, and the car sickness prevention program 44 loaded into the memory 36 is executed by the CPU 34, so that the seat ECU 32 functions as each of the functional units shown in Fig. 10. That is, in the second embodiment, the seat ECU 32 functions as an acceleration acquisition unit 50, a first estimation unit 52, an inclination angle calculation unit 54, and a seat angle control unit 60.

[0080] The seat angle control unit 60 controls the angle adjustment of the seat main body 12 by the angle adjustment devices 78, 82, 86 so that the inclination angles θhead and θupperbody of the head and trunk of an occupant seated in the vehicle seat main body 12 are equal to or greater than the inclination angle θ0 at which car sickness is suppressed, which is obtained by the inclination angle calculation unit 54. The seat angle control unit 60 is an example of a control unit in the present disclosure.

[0081] Next, referring to Fig. 11, only the parts of the car sickness prevention process 2 according to the second embodiment that are different from the first embodiment (Fig. 7) will be referred to. In the car sickness prevention process 2, steps 180 and 182 are performed instead of steps 150 and 152. That is, in step 180 of the car sickness prevention process 2, the acceleration acquisition unit 50 acquires from the travel route selection device 92 the planned travel route along which the vehicle is about to travel.

[0082] In step 182, the acceleration acquisition unit 50 acquires, from the acceleration DB 90, acceleration data stored in association with the roads of the planned travel route acquired in step 180, i.e., acceleration data detected by the acceleration sensor 74 when the vehicle previously traveled the planned travel route. The acceleration acquisition unit 50 also extracts, from the acquired acceleration data, acceleration components that are equal to or lower than a predetermined frequency and whose acceleration duration is equal to or longer than a predetermined time, and acquires the maximum value (=acceleration a) of the extracted acceleration components.

[0083] Furthermore, in the car sickness prevention process 2 according to the second embodiment, if the determination in step 162 or step 164 is negative, the process of step 186 is performed instead of step 166. That is, in step 186, the seat angle control unit 60 controls the seat angle adjustment by the angle adjustment devices 78, 82, 86 so that θhead>θ0 and θupperbody>θ0.

[0084] As an example, the seat angle control unit 60 refers to the conversion table 46 stored in the memory unit 58 and extracts, as the target angle, a combination of angles φ1, φ2, and φ3 of the seat main body 12 when the tilt angles θhead and θupperbody are equal to or greater than the tilt angle θ0. If multiple combinations of angles φ1, φ2, and φ3 are extracted, it is preferable to select, as the target angle, a combination that minimizes the difference between the current angles φ1, φ2, and φ3 of the seat main body 12 and the extracted combination. The seat angle control unit 60 then controls the seat angle adjustment by the angle adjustment devices 78, 82, and 86 so that the angles φ1, φ2, and φ3 of the seat main body 12 are each equal to or greater than the target angle.

[0085] As a result, the motors 80, 84, 88 of the angle adjustment devices 78, 82, 86 are driven so that the angles φ1, φ2, φ3 of the seat body 12 are equal to or greater than the target angles, thereby preventing the occupant's head from moving away from the headrest portion 18 when acceleration a is applied, thereby preventing the occurrence of car sickness. In the second embodiment, if the determinations in step 162 and step 164 are both positive, the car sickness prevention process 2 ends.

[0086] The second embodiment described above has the following advantages in addition to the advantages described in the first embodiment. That is, in the second embodiment, the seat angle control unit 60 controls the seat angle adjustment by the angle adjustment devices 78, 82, 86 so that the inclination angles θhead and θupperbody of an occupant seated in the vehicle seat main body 12 are each equal to or greater than the inclination angle θ0 at which car sickness is suppressed, which is obtained by the inclination angle calculation unit 54. In this way, the angle of the seat main body 12 is controlled to an angle at which car sickness is suppressed, thereby making it possible to suppress car sickness in an occupant seated in a vehicle seat.

[0087] Furthermore, in the second embodiment, the storage unit 58 associates the acceleration detected when the vehicle travels on a road with information indicating the road on which the vehicle traveled, and stores the information as the acceleration DB 90. The acceleration acquisition unit 50 acquires the planned travel route, and acquires, as the acceleration a, from the storage unit 58, the acceleration detected when the vehicle previously traveled on the road on which the vehicle will travel. This makes it possible to control the angle of the seat main body 12 to an angle that suppresses car sickness before the vehicle actually travels on the road.

[0088] In the second embodiment, the acceleration DB 90 is stored in the storage unit 38 (storage unit 58) on the vehicle side, but the present disclosure is not limited to this. For example, the acceleration DB 90 may be stored in an external server that receives acceleration data and information on the roads traveled from a plurality of vehicles, and the vehicle side may acquire the acceleration data, etc. from the acceleration DB 90 stored in the server.

[0089] In the second embodiment, acceleration data detected by the acceleration sensor 74 while the vehicle is traveling is associated with information identifying the road on which the vehicle traveled and stored in the acceleration DB 90, but the present disclosure is not limited to this. For example, a representative value of acceleration for each traffic situation (e.g., congested road, residential area, etc.) may be calculated based on the acceleration detected by the acceleration sensor 74 while the vehicle is traveling and stored in the DB. In this case, for example, the traffic situation may be determined from an image captured in front of the vehicle, and the representative value of acceleration corresponding to the determined traffic situation may be read from the DB and used. Furthermore, the traffic situation does not necessarily have to be determined from an image in front of the vehicle, but may also be obtained from an external server, etc.

[0090] Third Embodiment Next, a third embodiment of the present disclosure will be described. Note that the same parts as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0091] In the third embodiment, the car sickness prevention program 44 according to the third embodiment is read from the storage unit 38 and loaded into the memory 36, and the car sickness prevention program 44 loaded into the memory 36 is executed by the CPU 34, so that the seat ECU 32 functions as each of the functional units shown in Fig. 12. That is, in the third embodiment, the seat ECU 32 functions as a second estimation unit 100, an inclination angle acquisition unit 102, an acceleration calculation unit 104, and a first notification unit 106.

[0092] The second estimation unit 100 acquires the angles of the seat main body 12 (recline angle φ1, center-bending angle φ2, and headrest angle φ3), and estimates the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 from the acquired angles of the seat main body 12. The estimation of the inclination angles θhead and θupperbody by the second estimating unit 100 is performed based on the conversion table 46 stored in the memory unit 58.

[0093] The inclination angle acquisition unit 102 acquires the inclination angles θhead and θupperbody of the head and trunk of an occupant seated in the vehicle seat body 12 from the second estimation unit 100. The inclination angle acquisition unit 102 is an example of an acquisition unit in the present disclosure. The acceleration calculation unit 104 performs calculation processing of the above equation (1) to obtain an acceleration a0 at which car sickness is suppressed from the inclination angles θhead and θupperbody acquired by the inclination angle acquisition unit 102. The acceleration calculation unit 104 is an example of a calculation unit in the present disclosure.

[0094] The first notification unit 106 notifies the occupant by voice via the voice output unit 42 when the acceleration in the longitudinal direction of the vehicle being driven by the occupant is greater than the acceleration a at which car sickness is suppressed, which is obtained by the acceleration calculation unit 104. Note that instead of notifying the occupant by voice, the notification may be made by displaying a message on an in-vehicle display, for example.

[0095] Next, the car sickness prevention process 3 according to the third embodiment will be described with reference to Fig. 13. In step 200 of the car sickness prevention process 3, the second estimation unit 100 acquires the reclining angle φ1, the seat-folding angle φ2, and the headrest angle φ3 of the seat body 12 from the seat ECU 32.

[0096] In step 202, the second estimation unit 100 estimates the inclination angles θhead and θupperbody of the occupant from the angles φ1, φ2, and φ3 of the seat main body 12 acquired in step 200. The inclination angles θhead and θupperbody are estimated by reading out the inclination angles θhead and θupperbody associated with the angles φ1, φ2, and φ3 of the seat main body 12 from the conversion table 46 stored in the storage unit 58.

[0097] In step 204, the acceleration calculation unit 104 substitutes the tilt angle θhead of the occupant's head into equation (1) and performs the calculation process of equation (1) to obtain the acceleration a0_head at which car sickness is suppressed. The acceleration calculation unit 104 also substitutes the tilt angle θupperbody of the occupant's trunk into equation (1) and performs the calculation process of equation (1) to obtain the acceleration a0_upperbody at which car sickness is suppressed. The acceleration calculation unit 104 then sets the smaller of the acceleration a0_head and the acceleration a0_upperbody as the acceleration a0 at which car sickness is suppressed.

[0098] In step 206, first notification unit 106 acquires acceleration data for a certain period of time from acceleration sensor 74. In step 208, first notification unit 106 extracts acceleration components that are equal to or lower than a predetermined frequency and whose acceleration duration is equal to or longer than a predetermined period of time from the acceleration data acquired in step 206. Then, in step 210, first notification unit 106 acquires the maximum value (= acceleration a) of the acceleration components extracted in step 208.

[0099] In step 212, the first notification unit 106 determines whether the acceleration a acquired in step 210 is greater than the acceleration a0 at which car sickness is suppressed, calculated by the acceleration calculation unit 104. If the determination in step 212 is positive, it can be determined that there is a possibility that the occupant will suffer from car sickness, and the process proceeds to step 214.

[0100] In step 214, the first notification unit 106 notifies the driver by voice via the voice output unit 42 that the vehicle acceleration a is excessive. An example of the voice notification is, "There is a possibility of car sickness, so please try to drive with gentle acceleration and deceleration." This guides the driver to drive the vehicle so that the acceleration in the front-to-rear direction of the vehicle is less than the acceleration a0, thereby preventing the occupant seated in the seat body 12 of the vehicle from becoming car sick.

[0101] On the other hand, if the determination in step 212 is negative, it can be determined that the possibility of the occupant becoming car sick is low, so step 214 is skipped and the process returns to step 206.

[0102] As described above, in the third embodiment, the inclination angle acquisition unit 102 of the seat ECU 32 acquires the inclination angles θhead and θupperbody of the head and trunk of an occupant seated in the vehicle seat main body 12. Furthermore, the acceleration calculation unit 104 performs the calculation process of the above-mentioned equation (1) to obtain the acceleration a0 at which car sickness is suppressed from the inclination angles θhead and θupperbody acquired by the inclination angle acquisition unit 102. This makes it possible to accurately obtain the condition for determining whether or not an occupant seated in the vehicle seat main body 12 will suffer from car sickness (the acceleration a0 at which car sickness is suppressed).

[0103] In the third embodiment, the second estimating unit 100 acquires the angles φ1, φ2, and φ3 of the seat main body 12 and estimates the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 from the acquired angles φ1, φ2, and φ3 of the seat main body 12. The inclination angle acquiring unit 102 then acquires the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 from the second estimating unit 100. This simplifies the device configuration compared to an embodiment in which the inclination angles θhead and θupperbody are detected by a sensor, for example.

[0104] In the third embodiment, the storage unit 58 stores the relationship between the angles φ1, φ2, and φ3 of the seat main body 12 and the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 as a conversion table 46. The second estimating unit 100 estimates the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 from the angles φ1, φ2, and φ3 of the seat main body 12 based on the conversion table 46 stored in the storage unit 58. This simplifies processing compared to when the relationship between the angles φ1, φ2, and φ3 of the seat main body 12 and the inclination angles θhead and θupperbody of the occupant seated in the seat main body 12 is defined in advance using an arithmetic expression or the like.

[0105] Furthermore, in the third embodiment, the first notification unit 106 notifies when the longitudinal acceleration of the vehicle being driven by the occupant is greater than the acceleration a0 at which car sickness is suppressed, which is obtained by the acceleration calculation unit 104. This guides the driving of the vehicle so that the longitudinal acceleration of the vehicle is less than the acceleration a0, thereby suppressing the onset of car sickness in the occupant seated in the vehicle seat.

[0106] [Fourth embodiment] Next, a fourth embodiment of the present disclosure will be described. Note that the same parts as those in the first to third embodiments are given the same reference numerals, and the description thereof will be omitted.

[0107] In the fourth embodiment, the car sickness prevention program 44 according to the fourth embodiment is read from the storage unit 38 and loaded into the memory 36, and the car sickness prevention program 44 loaded into the memory 36 is executed by the CPU 34, so that the seat ECU 32 functions as each of the functional units shown in Fig. 14. That is, in the fourth embodiment, the seat ECU 32 functions as a second estimation unit 100, an inclination angle acquisition unit 102, an acceleration calculation unit 104, and a second notification unit 108.

[0108] The second notification unit 108 notifies the driving route selection device 92 of the acceleration a at which car sickness is suppressed, obtained by the acceleration calculation unit 104, so that a driving route is selected as the vehicle driving route where the acceleration in the forward / backward direction of the vehicle while driving is equal to or less than the acceleration a0 at which car sickness is suppressed.

[0109] Next, referring to Fig. 15, car sickness prevention process 4 according to the fourth embodiment will be described, focusing only on the differences from car sickness prevention process 3 (Fig. 13) described in the third embodiment. Steps 200 to 204 are the same as those in the third embodiment. In the next step 220, the acceleration calculation unit 104 acquires from the travel route selection device 92 the planned travel route along which the vehicle is about to travel.

[0110] In step 222, the acceleration calculation unit 104 obtains from the acceleration DB 90 acceleration data stored in association with the roads of the planned travel route obtained in step 220, i.e., acceleration data detected by the acceleration sensor 74 when the vehicle previously traveled the planned travel route. The acceleration calculation unit 104 also extracts, from the obtained acceleration data, acceleration components that are equal to or lower than a predetermined frequency and whose acceleration duration is equal to or longer than a predetermined time, and obtains the maximum value (=acceleration a) of the extracted acceleration components.

[0111] In step 212, the second notification unit 108 determines whether the acceleration a acquired in step 222 is greater than the acceleration a0 at which car sickness is suppressed, calculated in step 204. If the determination in step 212 is positive, it can be determined that the occupant is highly likely to suffer from car sickness, and the process proceeds to step 224.

[0112] In step 224, the second notification unit 108 requests the driving route selection device 92 to modify the planned driving route acquired in step 220 by notifying the driving route selection device 92 of the acceleration a of the vehicle being an acceleration a0 at which car sickness is suppressed. As a result, the driving route selection device 92 selects a driving route in which the longitudinal acceleration of the vehicle while driving is less than the acceleration a by modifying the planned driving route to, for example, a route that avoids congested roads and stop signs where large accelerations are likely to occur while driving. This makes it possible to prevent the occurrence of car sickness in the occupant seated in the vehicle seat body 12. Note that if the determination in step 212 is negative, it can be determined that the occupant is unlikely to become car sick, and therefore the car sickness prevention process 4 is terminated.

[0113] The fourth embodiment described above has the following advantages in addition to the advantages described in the third embodiment. That is, in the fourth embodiment, the second notification unit 108 notifies the driving route selection device 92 of the acceleration a0 at which car sickness is suppressed, obtained by the acceleration calculation unit 104, so that a driving route is selected as the vehicle driving route on which the longitudinal acceleration of the vehicle while traveling is equal to or less than the acceleration a0 at which car sickness is suppressed. This makes it possible to suppress car sickness in occupants seated in the vehicle seats.

[0114] The seat body 12 may be configured to be rotatable so as to face backward. When the occupant faces backward, the calculation may be performed using the acceleration during acceleration instead of the acceleration during deceleration.

[0115] Although the above describes an embodiment in which the present disclosure is applied to a passenger seat of a vehicle, the present disclosure is not limited to this. For example, the present disclosure may be applied to a rear seat of a vehicle, or a plurality of vehicle seats according to the present disclosure may be provided in a single vehicle.

[0116] Furthermore, although the above describes an example of a car sickness prevention program 44 according to the present disclosure, which is pre-stored (installed) in the memory unit 38, the car sickness prevention program according to the present disclosure can also be provided in a form recorded on a non-temporary recording medium such as an HDD, SSD, or DVD. [Explanation of symbols]

[0117] 10 Vehicle seats 12 Seat body 24 Reclining angle φ1 sensor 28 Center bending angle φ2 sensor 31 Headrest φ3 sensor 32 Seat ECU 42 Audio output section 44 Car Sickness Prevention Program 46 Conversion Table 50 Acceleration acquisition section (acquisition section) 52 1st estimation part 54 Inclination angle calculation section (calculation section) 56 Seat angle adjustment guide (guide) 58 Memory section 60 Seat angle control unit (control unit) 90 Acceleration DB 100 Second estimation part 102 Tilt angle acquisition section (acquisition section) 104 Acceleration calculation section (calculation section) 106 First Notification Department 108 Second Notification Department

Claims

1. an acquisition unit that acquires acceleration a in a first direction acting on the head of an occupant seated in a vehicle seat in a direction in which the head moves away from a headrest portion of the seat in the longitudinal direction of the vehicle, or an inclination angle θhead of the occupant's head, which is an angle formed by a line along the major axis direction of an ellipsoid simulating the occupant's head and a line along the vertical direction, and an inclination angle θupperbody of the occupant's torso, which is an angle formed by a line along the longitudinal direction of a rectangular parallelepiped simulating the occupant's torso and a line along the vertical direction; <h2 style=";text-align:left;direction:ltr">θ>tan<h2 style=";text-align:left;direction:ltr"> －１ <h2 style=";text-align:left;direction:ltr"> (a / g) …(11) a calculation unit that obtains, from the acceleration a in the first direction acquired by the acquisition unit, the tilt angle θ of the head and torso of the occupant that satisfies the above equation (1) as the tilt angle θ of the head and torso of the occupant at which car sickness is suppressed, where g is the acceleration of gravity, a is the acceleration in the first direction, and θ is the tilt angle of the head and torso of the occupant (where θ in equation (1) above is 0°<θ<90°); or obtains, from the tilt angles θ and θ acquired by the acquisition unit, the acceleration a in the first direction that satisfies the above equation (1), as the acceleration a in the first direction at which car sickness is suppressed; A car sickness prevention device including:

2. The car sickness prevention device according to claim 1 , wherein the acquisition unit acquires, as the acceleration a in the first direction, a maximum value among acceleration components having a frequency equal to or lower than a predetermined frequency from data on the acceleration in the longitudinal direction of the vehicle within a certain period of time.

3. The car sickness prevention device of claim 1 or claim 2, wherein the acquisition unit acquires, as the acceleration a in the first direction, the maximum value of acceleration components whose acceleration duration is equal to or longer than a predetermined time (where the predetermined time is less than the predetermined time) from data on the acceleration in the forward / backward direction of the vehicle within a certain period of time.

4. a first estimation unit that estimates inclination angles θhead and θupperbody of a head and a torso of an occupant seated on the seat from the angle of the seat, The car sickness suppression device according to any one of claims 1 to 3, wherein the calculation unit performs processing to determine whether or not the inclination angles θhead and θupperbody of the head and torso of the occupant estimated by the first estimation unit satisfy the equation (1) into which the acceleration a in the first direction acquired by the acquisition unit is substituted.

5. The seating arrangement further includes a storage unit that stores a relationship between the seat angle and the inclination angles θhead and θupperbody of the head and torso of an occupant seated on the seat, 5. The car sickness prevention device according to claim 4, wherein the first estimation unit estimates the inclination angles θhead and θupperbody of the head and torso of the occupant from the angle of the seat based on the information stored in the memory unit.

6. A car sickness suppression device as described in any one of claims 1 to 5, further comprising a guide unit that guides the occupant in adjusting the angle of the seat so that the inclination angles θhead and θupperbody of the head and torso of the occupant seated in the seat of the vehicle are each equal to or greater than the inclination angle θ0 of the head and torso of the occupant at which car sickness is suppressed, obtained by the calculation unit.

7. A car sickness suppression device as described in any one of claims 1 to 5, further comprising a control unit that controls the angle adjustment of the seat by the seat angle adjustment device so that the inclination angles θhead and θupperbody of the head and torso of an occupant sitting in a seat of the vehicle are each equal to or greater than the inclination angle θ0 of the head and torso of the occupant at which car sickness is suppressed, obtained by the calculation unit.

8. The vehicle further includes a second estimation unit that acquires the seat angle and estimates the inclination angles θhead and θupperbody of the head and torso of an occupant sitting on the seat from the acquired seat angle; The car sickness prevention device according to claim 1 , wherein the acquisition unit acquires the inclination angles θ head and θ upper body of the head and torso of the occupant seated in the seat from the second estimating unit.

9. The seating arrangement further includes a storage unit that stores a relationship between the seat angle and the inclination angles θhead and θupperbody of the head and torso of an occupant seated on the seat, 9. The car sickness prevention device according to claim 8, wherein the second estimation unit estimates the inclination angles θhead and θupperbody of the head and torso of the occupant from the angle of the seat based on the information stored in the memory unit.

10. A car sickness suppression device as described in any one of claims 1, 8, and 9, further including a first notification unit that notifies when the acceleration a in the first direction of the vehicle being driven by the occupant is greater than the acceleration a0 in the first direction at which car sickness is suppressed, obtained by the calculation unit.

11. A car sickness suppression device as described in any one of claims 1, 8 and 9, further including a second notification unit that notifies a driving route selection device of the acceleration a0 in the first direction at which car sickness is suppressed, obtained by the calculation unit, so that a driving route is selected as the driving route for the vehicle such that the acceleration a in the first direction of the vehicle while driving is equal to or less than the acceleration a0 in the first direction at which car sickness is suppressed.

12. A seat body on which a vehicle occupant sits; A car sickness prevention device according to any one of claims 1 to 11, 1. A vehicle seat including:

13. Acquire an acceleration a in a first direction acting on the head of an occupant seated in a seat of the vehicle in a direction in which the head moves away from the headrest portion of the seat in the longitudinal direction of the vehicle, or an inclination angle θhead of the head of the occupant, which is the angle formed by a line along the longitudinal direction of an ellipsoid simulating the head of the occupant and a line along the vertical direction, and an inclination angle θupperbody of the torso of the occupant, which is the angle formed by a line along the longitudinal direction of a rectangular parallelepiped simulating the torso of the occupant and a line along the vertical direction, θ>tan -1 (a / g)...(1) When the acceleration of gravity is g, the acceleration in the first direction is a, and the tilt angle of the head and torso of the occupant is θ (where θ in the above formula (1) is 0°<θ<90°), the tilt angle θ of the head and torso of the occupant that satisfies the above formula (1) is obtained from the acquired acceleration a in the first direction as the tilt angle θ of the head and torso of the occupant at which car sickness is suppressed, or the acceleration a in the first direction that satisfies the above formula (1) is obtained as the acceleration a in the first direction as which car sickness is suppressed from the acquired tilt angles θhead and θupperbody of the head and torso of the occupant. A method for operating a car sickness prevention device, in which a computer executes a process including the steps of:

14. A computer comprising: an acceleration a in a first direction acting on the head of an occupant seated in a vehicle seat in a direction in which the head moves away from a headrest portion of the seat in the longitudinal direction of the vehicle, or an inclination angle θhead of the head, which is an angle formed by a line along the major axis direction of an ellipsoid simulating the head of the occupant, and a line along the vertical direction, and an inclination angle θupperbody of the torso, which is an angle formed by a line along the longitudinal direction of a rectangular parallelepiped simulating the torso of the occupant, and a line along the vertical direction; θ>tan -1 (a / g)...(1) When the acceleration of gravity is g, the acceleration in the first direction is a, and the tilt angle of the head and torso of the occupant is θ (where θ in the above formula (1) is 0°<θ<90°), the tilt angle θ of the head and torso of the occupant that satisfies the above formula (1) is obtained from the acquired acceleration a in the first direction as the tilt angle θ of the head and torso of the occupant at which car sickness is suppressed, or the acceleration a in the first direction that satisfies the above formula (1) is obtained as the acceleration a in the first direction as which car sickness is suppressed from the acquired tilt angles θhead and θupperbody of the head and torso of the occupant. A car sickness prevention program for executing a process including the above.

Images