Reproduction device, control method for reproduction device, and information processing program for reproduction device

Abstract

This reproduction device comprises: an acquisition unit that acquires information on a traveling state of a moving body; and a reproduction unit that causes a display device provided on the moving body to reproduce one or more videos having at least a part of a region including a moving object. When the traveling state satisfies a first condition, the reproduction unit causes at least one of the arrangement of the region in the video, the moving speed of the object, and the direction of movement of the object to reproduce the video satisfying a sickness suppression condition for suppressing motion sickness of an occupant riding on the moving body.

Description

Playback device, playback device control method, and playback device information processing program

[0001] The present disclosure relates to a playback device, a control method for a playback device, and an information processing program for a playback device.

[0002] Patent Literature 1 discloses a technology for suppressing motion sickness in a passenger by conveying future behavior information of a moving object to the passenger of the moving object. Specifically, Patent Literature 1 converts the future behavior information of the moving object into a stimulating display, and displays the stimulating display on a display means by superimposing it on a content image (video) such as a movie or television. In this way, by presenting the future behavior information of the moving object to the passenger through the stimulating display, the passenger's attention is directed to the traveling direction of the moving object, thereby suppressing motion sickness in the passenger.

[0003] In the technology described in Patent Document 1, the occupant's gaze is so focused on the stimulating display that the swaying of the occupant's body and their vision become misaligned, which may actually cause the occupant to become motion sick.

[0004] Patent No. 5157134

[0005] The present disclosure has been made to solve such problems, and aims to provide a playback device that can present images to occupants that can prevent the occupants from experiencing motion sickness.

[0006] A playback device in one aspect of the present disclosure is a playback device provided on a moving body, and includes an acquisition unit that acquires information regarding the traveling state of the moving body, and a playback unit that causes a display device provided on the moving body to play one or more videos, at least a portion of which has an area that includes a moving object, and when the traveling state satisfies a first condition, the playback unit plays the video in which at least one of the arrangement of the area in the video, the moving speed of the object, and the moving direction of the object satisfies a sickness prevention condition for suppressing motion sickness in occupants of the moving body.

[0007] According to the present disclosure, it is possible to present to the occupant an image that can prevent the occupant from experiencing motion sickness.

[0008] 1 is a diagram showing an example of the internal configuration of a moving body to which a playback device according to the present disclosure is applied. FIG. 2 is a block diagram showing an example of the configuration of the moving body shown in FIG. 1. FIG. 3 is a flowchart showing an example of an overall image of processing by a moving body according to embodiment 1. FIG. 4 is a diagram showing a first video which is an example of a video which satisfies the sickness suppression condition. FIG. 5 is a block diagram showing an example of the configuration of a moving body according to embodiment 2. FIG. 6 is a diagram showing a second video which is another example of a video which satisfies the sickness suppression condition. FIG. 7 is a diagram showing a third video which is yet another example of a video which satisfies the sickness suppression condition.

[0009] (Background to the present disclosure) It is known that motion sickness occurs when a passenger's physical sensations and visual senses do not match. For example, motion sickness can occur in a situation where the passenger's gaze is fixed even though the passenger's body is shaking, such as when the passenger reads a book while the vehicle is moving.

[0010] In recent years, various types of images have been provided to passengers aboard moving vehicles. For example, the stimulus information described in Patent Document 1 may be presented to the passengers in order to prevent the passengers from experiencing motion sickness.

[0011] Here, with the technology described in Patent Document 1 above, the occupant's gaze is so focused on the behavior of the stimulus display that the occupant's body swaying does not match the occupant's vision, which may actually cause the occupant to become motion sick.

[0012] In order to solve the above problems, the following techniques are disclosed.

[0013] (1) A playback device in one aspect of the present disclosure is a playback device provided in a moving body, and includes an acquisition unit that acquires information regarding the traveling state of the moving body, and a playback unit that causes a display device provided in the moving body to play one or more videos, at least a portion of which has an area that includes a moving object, and when the traveling state satisfies a first condition, the playback unit plays the video in which at least one of the arrangement of the area in the video, the moving speed of the object, and the moving direction of the object satisfies a sickness prevention condition for suppressing motion sickness in occupants of the moving body.

[0014] In this playback device, the playback unit plays back the video that satisfies the sickness prevention conditions for preventing motion sickness in a passenger aboard a moving vehicle. Here, the sickness prevention conditions are met by at least one of the layout of an area including an object, the speed of movement of the object, and the direction of movement of the object, and are not achieved by focusing the passenger's attention on one point or fixing their vision. Therefore, with the above configuration, it is possible to present the passenger with video that can prevent motion sickness in the passenger.

[0015] (2) In the playback device described in (1) above, the first condition may include at least one of the following: the moving body is moving; and a predetermined time has not elapsed since the moving body came to a halt.

[0016] According to this configuration, an image that satisfies the sickness suppression condition can be displayed when the moving object is moving, or when a predetermined time has not yet elapsed since the moving object stopped moving, i.e., when the moving object is temporarily stopped. In other words, according to the above configuration, an image that can suppress motion sickness in the occupant can be presented to the occupant at a time when the occupant may experience motion sickness. Therefore, motion sickness in the occupant can be effectively suppressed.

[0017] (3) In the playback device described in (1) or (2) above, the sickness suppression condition may be that when the video is divided into a lower part and an upper part, the area is located in the lower part and the upper part is in a stationary state.

[0018] It is generally known that occupants are more likely to experience motion sickness in situations where they experience mental stress. Therefore, it can be said that images that make occupants feel stressed are images that make occupants more likely to experience motion sickness. In contrast, with the above configuration, an image in which an area including a moving object is located at the bottom is presented to the occupant. Here, since a composition in which an area including a moving object is located at the bottom is often seen in the real world, an image with this composition does not cause discomfort to the occupant and is less likely to cause stress to the occupant. Therefore, with the above configuration, it is possible to present to the occupant an image that can effectively prevent the occupant from experiencing motion sickness.

[0019] (4) In the playback device described in (3) above, the upper part of the video may be arranged with another area different from the area, the other area including another object moving within the other area, and the playback unit may play the video in which the moving speed of the object is faster than the moving speed of the other object.

[0020] As described above, an image that causes stress to the occupant can be said to be an image that makes the occupant more susceptible to motion sickness. According to the above configuration, an image in which an object located in the lower part of the image moves faster than another object located in the upper part of the image is presented to the occupant. Because this image is a reproduction of a scene often seen in the real world, it does not cause discomfort to the occupant and is unlikely to cause stress to the occupant. Therefore, according to the above configuration, an image that can effectively prevent the occupant from experiencing motion sickness can be presented to the occupant.

[0021] (5) The playback device described in (4) above may further include a speed adjustment unit that performs a speed adjustment process to make the movement speed of the object relatively faster than the movement speed of the other object, and the playback unit may cause the display device to play the video that has been subjected to the speed adjustment process.

[0022] According to this configuration, the speed adjustment unit executes the speed adjustment process to generate an image in which an object located in the lower part of the image moves faster than another object located in the upper part of the image. In other words, an image that reproduces scenes often seen in the real world and is less likely to cause stress to the occupants is generated. Furthermore, with the above configuration, the image generated by the above speed adjustment process is presented to the occupants, thereby effectively preventing the occupants from experiencing motion sickness.

[0023] (6) In the playback device described in any one of (1) to (5) above, the sickness suppression condition may be that the movement speed of the object is set within a range of 100 pix / s to 3500 pix / s when the unit of time is 1 second (s) and the unit of length of the movement distance of the object is 1 pixel (pix).

[0024] It is generally known that occupants are more likely to experience motion sickness in situations where they experience mental stress. In other words, images that cause stress to occupants are images that make occupants more likely to experience motion sickness. However, images in which objects move at excessively fast or excessively slow speeds are not consistent with the real world, and therefore, when presented to occupants, these images may cause discomfort to the occupants, which may lead to stress. According to the above configuration, an image in which the object's movement speed is set within a range of 100 pixel / s to 3500 pixel / s is presented to the occupants. That is, an image in which the object's movement speed is set to a speed that appropriately reproduces the movement speed of an object in the real world is presented to the occupants. This reduces the occupants' stress, thereby effectively reducing the occupants' experience of motion sickness.

[0025] (7) In the playback device described in any one of (1) to (6) above, the sickness suppression condition may be that the object moves in a direction corresponding to the traveling direction of the moving body.

[0026] After various studies, the inventors of the present application found that if an image in which an object moves in a direction that does not correspond to the moving direction of a moving object is presented to a passenger, the passenger will feel uncomfortable. For example, if an image in which an object moves in the vertical direction of the image is presented to a passenger even though the moving object is moving forward, the passenger will feel uncomfortable due to a mismatch between their physical sensations and their visual sense. The stress associated with this discomfort can cause motion sickness in the passenger. In contrast, with the above configuration, an image in which an object moves in a direction that corresponds to the moving direction of the moving object is presented to the passenger. This reduces the passenger's discomfort, thereby effectively preventing the passenger from experiencing motion sickness.

[0027] (8) In the playback device described in (7) above, the playback unit may cause the display device to play the video in which, when the moving body moves forward, the proportion of the area occupied by the object increases as the object moves up and down within the area.

[0028] The inventors of the present application have found that if an image of an object moving toward the occupant is presented to the occupant when the moving body is moving forward, the occupant's physical sensations and visual senses will accurately match, making the occupant less likely to experience motion sickness. Here, according to the above configuration, when the moving body is moving forward, an image is presented to the occupant in which the proportion of the area occupied by the object increases as the object moves. In this way, when the moving body is moving forward, an image is presented to the occupant that gives the visual effect of the object moving toward the occupant, making it possible to more effectively prevent the occupant from experiencing motion sickness.

[0029] In this specification, "an object moving in the vertical direction" means that the object is moving in a direction that includes a vertical component. Therefore, when an object moves diagonally upward or downward, it can also be considered to be moving in the vertical direction.

[0030] (9) In the playback device described in (8) or (7) above, the playback unit may cause the display device to play the video in which the proportion of the area occupied by the object decreases as the object moves up and down within the area when the moving body retreats.

[0031] The inventors of the present application have found that if an image of an object moving away from the occupant is presented to the occupant when the moving body is reversing, the occupant's physical sensations and visual senses will accurately match, making the occupant less likely to experience motion sickness. Here, according to the above configuration, when the moving body is reversing, an image is presented to the occupant in which the proportion of the area occupied by the object decreases as the object moves. In this way, when the moving body is reversing, an image is presented to the occupant that gives the visual effect of the object moving away from the occupant, thereby more effectively preventing the occupant from experiencing motion sickness.

[0032] (10) Another aspect of the present disclosure is a control method for a playback device provided in a moving body, which acquires information regarding the traveling state of the moving body, and plays one or more images, at least a portion of which has an area including a moving object, on a display device provided in the moving body, and, when the traveling state satisfies a first condition, plays the images in which at least one of the arrangement of the area in the image, the moving speed of the object, and the moving direction of the object satisfies a sickness prevention condition for suppressing motion sickness in a passenger on the moving body.

[0033] This configuration makes it possible to provide a control method that can achieve the same effects as the playback device described above.

[0034] (11) In another aspect of the present disclosure, an information processing program is an information processing program for a playback device provided in a moving body, which causes a computer to acquire information regarding the traveling state of the moving body, play one or more images having an area in at least a portion of which includes a moving object on a display device provided in the moving body, and, when the traveling state satisfies a first condition, play the images in which at least one of the arrangement of the area in the image, the moving speed of the object, and the moving direction of the object satisfies a sickness prevention condition for suppressing motion sickness in occupants of the moving body.

[0035] According to this configuration, it is possible to provide an information processing program that can achieve the same effects as the playback device.

[0036] The present disclosure can also be realized as an information processing system operated by such an information processing program. Needless to say, such a computer program can be distributed on a non-transitory computer-readable recording medium such as a CD-ROM or via a communication network such as the Internet.

[0037] Note that each of the embodiments described below represents a specific example of the present disclosure. The numerical values, shapes, components, steps, and step orders shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept are described as optional components. Furthermore, in all of the embodiments, the respective contents can be combined.

[0038] (Embodiment 1) FIG. 1 is a diagram illustrating an example of the internal configuration of a mobile object 10 to which a playback device 40 according to the present disclosure is applied. The mobile object 10 is an electric vehicle that has a battery, e.g., a rechargeable secondary battery, and moves by supplying power charged in the battery to an electric motor (not shown). However, the mobile object 10 is not limited to an electric vehicle, and may be a gasoline-powered vehicle, a ship, an airplane, a train, a bus, a bullet train, or the like. The mobile object 10 may also be a vehicle equipped with an automatic driving system. As illustrated in FIG. 1 , the mobile object 10 includes a driver's seat 11 for the driver of the mobile object 10, a seat 12 disposed behind the driver's seat 11 for a passenger P riding with the driver, and a display device 13 disposed between the driver's seat 11 and the seat 12. The display device 13 is a monitor that plays back a video that suppresses motion sickness in the passenger P. However, the display device 13 may be a VR (Virtual Reality) goggle, an AR (Augmented Reality) goggle, a smartphone, a tablet computer, or the like, provided on the moving body 10. It may also be a projection system including a projector and a screen. D1 in FIG. 1 indicates the forward direction (front) of the moving body 10, and D2 in FIG. 1 indicates the backward direction (rear) of the moving body 10.

[0039] Fig. 2 is a block diagram showing an example of the configuration of the mobile object 10 shown in Fig. 1. In addition to the driver's seat 11, the seat 12, and the display device 13 shown in Fig. 1, the mobile object 10 further includes a speaker 14, a lighting device 15, a mobile object controller 20, a car navigation device 30, a playback device 40, a video control unit 434, an audio control unit 435, and a lighting control unit 436. In addition, the mobile object 10 further includes various sensors (not shown).

[0040] The speaker 14 reproduces sounds such as music and other sounds.

[0041] The lighting device 15 is installed, for example, on the ceiling of the moving body 10 and emits light at a predetermined color temperature.

[0042] The mobile object controller 20 is configured with a computer such as an ECU (Electronic Control Unit), and controls the overall operation of the mobile object 10 based on information detected by various sensors provided in the mobile object 10 .

[0043] The various sensors included in the mobile object 10 include a positioning sensor 21, a traveling direction sensor 22, a timer 23, and a wheel speed sensor 24. The positioning sensor 21 measures the position information of the current location of the mobile object 10. The positioning sensor 21 is configured, for example, by a GPS (Global Positioning System) sensor. The traveling direction sensor 22 detects the traveling direction of the mobile object 10. The traveling direction sensor 22 is configured, for example, by a LIDAR (Light Detection and Ranging) or millimeter-wave radar. In this case, the traveling direction sensor 22 detects the traveling direction of the mobile object 10 by measuring the distance and relative speed between the mobile object 10 and objects around the mobile object 10. The timer 23 measures the time elapsed since the mobile object 10 came to a stop. The wheel speed sensor 24 measures the rotational speed of the wheels of the mobile object 10. In addition, the moving body 10 may be equipped with a steering angle sensor, an inertial sensor, etc. The steering angle sensor detects the angle of the front wheels of the moving body 10. The inertial sensor is a sensor that detects inertial momentum and is made up of a three-axis angular velocity sensor and a three-directional acceleration sensor, and detects the behavior of the moving body 10.

[0044] The car navigation device 30 has a memory (not shown) and presents the driver with a route to the destination based on map data stored in the memory and the current location information of the mobile object 10 acquired by the positioning sensor 21. The car navigation device 30 is connected to the mobile object controller 20 so as to be able to send and receive various information and signals.

[0045] The playback device 40 is placed, for example, in a console box of the mobile object 10, and includes a communication interface 41, a memory 42, a central processing unit 43, and peripheral circuits (not shown).

[0046] The communication interface 41 is configured with a communication circuit for communicatively connecting the playback device 40 to the mobile object controller 20 and the car navigation device 30. Specifically, the communication interface 41 has a function of transmitting and receiving data and signals between the mobile object controller 20 and the car navigation device 30 via a communication circuit that uses a wireless LAN, Bluetooth (registered trademark), a communication network of a mobile information terminal carrier, or the like. Note that the communication interface 41 may also transmit and receive data and signals via a wired communication method.

[0047] The memory 42 is configured by, for example, a read-only memory (ROM), a random access memory (RAM), an electrically erasable and rewritable ROM (EEPROM), etc. The memory 42 stores a control program that operates the central processing unit 43. The memory 42 also stores a video database 421 in which various videos are recorded. The videos recorded in the video database 421 include videos intended to prevent passengers from becoming motion sick.

[0048] The central processing unit 43 is configured by an electronic circuit such as a CPU, etc. The central processing unit 43 operates in accordance with a control program stored in the memory 42, thereby functioning as an acquisition unit 431, a determination unit 432, and a content control unit 433 (an example of a playback unit).

[0049] The acquisition unit 431 acquires various types of information related to the mobile body 10. For example, the acquisition unit 431 acquires running state information, which is information related to the running state of the mobile body 10. The running state information includes information indicating the rotation speed of the wheels of the mobile body 10, the time elapsed since the mobile body 10 stopped running, and the traveling direction of the mobile body 10.

[0050] The determination unit 432 determines whether the traveling state of the mobile body 10 satisfies a first condition based on the traveling state information acquired by the mobile body 10. The first condition includes at least one of the following: the mobile body 10 is traveling; and a predetermined time has not elapsed since the mobile body 10 came to a stop. The determination unit 432 according to this embodiment determines that the first condition is satisfied when either of these conditions is satisfied. That is, the determination unit 432 determines that the first condition is satisfied when the mobile body 10 is traveling, and determines that the first condition is satisfied when the mobile body 10 has stopped traveling but the predetermined time has not elapsed since the mobile body 10 came to a stop.

[0051] The content control unit 433 determines to play one or more videos, at least a part of which has an area including a moving object, on the display device 13. In particular, when the traveling state of the moving body 10 satisfies a first condition, the video control unit 434 determines to play, on the display device 13, a video in which at least one of the arrangement of areas in the video, the moving speed of the object, and the moving direction of the object satisfies a sickness prevention condition for preventing motion sickness in the occupant P riding in the moving body 10.

[0052] The content control unit 433 also generates a video playback signal for playing the video on the display device 13. Furthermore, the content control unit 433 generates a sound playback signal for outputting sounds such as background music and sound effects to be played in synchronization with the video from the speaker 14. Furthermore, the content control unit 433 generates a lighting output signal for outputting a predetermined lighting pattern from the lighting device 15.

[0053] The video control unit 434 is configured with a drive circuit that drives the display device 13 , and controls the operation of the display device 13 in accordance with the video playback signal from the content control unit 433 .

[0054] The audio control unit 435 is configured with a drive circuit (for example, an amplifier) ​​that drives the speaker 14 , and controls the operation of the speaker 14 in accordance with the audio reproduction signal from the content control unit 433 .

[0055] The lighting control unit 436 is configured with a drive circuit that drives the lighting device 15 , and controls the operation of the lighting device 15 in accordance with a lighting control signal from the content control unit 433 .

[0056] The processing of the moving body 10 configured as described above will be described with reference to the flowchart of Fig. 3. Fig. 3 is a flowchart showing an example of an overall image of the processing of the moving body 10 according to the first embodiment.

[0057] In step S101, the mobile object controller 20 detects that the mobile object 10 has started to move.

[0058] In step S102, the acquisition unit 431 acquires traveling state information of the mobile object 10. As described above, the traveling state information includes the rotation speed of the wheels of the mobile object 10, the time that has elapsed since the mobile object 10 stopped traveling, and information indicating the traveling direction of the mobile object 10. Below, an example will be described in which the acquisition unit 431 confirms that the mobile object 10 is traveling in the direction (forward) indicated by the arrow D1 in FIG. 1 .

[0059] In step S103, the determination unit 432 determines whether the mobile object 10 is moving based on the rotational speed of the wheels of the mobile object 10. Specifically, the determination unit 432 according to this embodiment determines that the mobile object 10 is moving when the rotational speed of the wheels of the mobile object 10 is equal to or greater than a predetermined reference speed. Conversely, when the rotational speed of the wheels of the mobile object 10 is less than the reference speed, the determination unit 432 determines that the mobile object 10 is stopped.

[0060] If the moving object 10 is moving (Yes in step S103), the process proceeds to step S105. If the moving object 10 is stopped (No in step S103), the process proceeds to step S104.

[0061] In step S104, the determination unit 432 determines whether a predetermined time has elapsed since the moving body 10 stopped moving. The predetermined time is, for example, five minutes. If the predetermined time has elapsed since the moving body 10 stopped moving (Yes in step S104), the processing ends. If the predetermined time has not elapsed since the moving body 10 stopped moving (No in step S104), the processing proceeds to step S105. That is, in steps S103 and S104, a determination is made as to whether the moving state of the moving body 10 satisfies the first condition.

[0062] In step S105, the content control unit 433 determines to play one or more images that have at least a portion of an area that includes a moving object and that satisfy the sickness prevention condition on the display device 13. In this embodiment, the sickness prevention condition is any one of the conditions (1) to (4) below.

[0063] (1) When the video is divided into a lower portion and an upper portion, the area containing the moving object is located in the lower portion of the video, while the upper portion is stationary. Note that the "lower portion" of the video refers to the portion located below the reference line L (Figure 4), which is a virtual straight line extending in the left-right direction so as to divide the video into a lower portion and an upper portion. Similarly, the "upper portion" refers to the portion located above the reference line L.

[0064] (2) When the unit of time is 1 second (s) and the unit of length of the object's movement distance is 1 pixel (pix), the object's movement speed is set within the range of 100 pix / s to 3500 pix / s.

[0065] (3) The object moves in a direction corresponding to the traveling direction of the moving body 10. In this embodiment, "the direction corresponding to the traveling direction of the moving body 10" refers to the direction along the traveling direction of the moving body 10. As explained in step S102, in this example, the moving body 10 is moving forward. Therefore, in this case, "the direction corresponding to the traveling direction of the moving body 10" refers to the front-to-rear direction. Therefore, the above-mentioned "the object moves in a direction corresponding to the traveling direction of the moving body 10" refers to the object moving along the front-to-rear direction in the image. Note that "the object moves" means that the coordinates of the object change from a predetermined coordinate to another coordinate in the two-dimensional space of the image, thereby giving the occupant P a visual effect that makes it appear as if the object has moved.

[0066] (4) The moving speed of an object placed in the lower portion is faster than the moving speed of another object placed in the upper portion.

[0067] An image that satisfies any one of the above conditions (1) to (4) is an image that can suppress sickness in the occupant P, that is, an image that satisfies the sickness suppression condition. In step S105, the content control unit 433 determines to play, for example, the image shown in Figure 4 on the display device 13.

[0068] FIG. 4 shows a first image M1 that satisfies all of the above-described conditions (1) to (4). Such images are stored in the image database 421. The first image M1 is an image showing flowing river water. As shown in FIG. 4, the first image M1 has a lower portion S1 located below a reference line L that divides the first image M1 into two equal parts vertically, and an upper portion S2 located above the reference line L. The lower portion S1 includes a river area A1 in which the river is displayed. The river area A1 includes water 110, an object moving within the river area A1. As indicated by arrow C1 in FIG. 4, the water 110 moves in a downward and rightward direction within the river area A1. The upper portion S2 of the first image M1 includes a sky area A2 in which the sky is displayed. The sky area A2 includes a sun 120, another object moving within the sky area A2. The sun 120 moves within the sky region A2 in the direction indicated by the arrow C2 in Figure 4. Furthermore, the upper portion S2 of the first image M1 includes a tree region A3, which is an area in which trees are projected. The tree region A3 includes leaves 130, which are separate objects that move within the tree region A3. Specifically, the leaves 130 sway (move) within the tree region A3 in the direction indicated by the arrow C3.

[0069] Regarding (1), it is generally known that occupant P is more likely to experience motion sickness in situations where the occupant P experiences mental stress. Here, a composition in which an area including a moving object is located in the lower portion and the upper portion of the image is stationary is often seen in natural landscapes in the real world. Therefore, an image having this composition does not cause discomfort to the occupant P and is less likely to cause stress to the occupant P. In other words, the occupant P is less likely to experience motion sickness. Note that a "stationary state" includes at least one of a completely stationary state and a state in which an object appears stationary. A "stationary state" refers to a state in which an object appears stationary when the occupant P watches the image in a normal seated position in the seat 12, but when the occupant P enlarges the image or moves closer to the display device 13, it becomes apparent that another object located in the upper portion of the image is moving slightly. For example, if the moving speed of another object is set to 10 pixels / s or less, the object can be said to be stationary. In the first image M1, the river area A1 is located in the lower portion S1, and the movement speed of water 110, which is an object moving within the river area A1, is set to 100 pixels / second. In the first image M1, the sky area A2 and the tree area A3 are located in the upper portion S2, and the movement speed of sun 120, which is another object moving within the sky area A2, is set to 10 pixels / second, and the movement speed of leaves 130, which is another object moving within the tree area A3, is set to 10 pixels / second. By presenting such a first image M1 to the occupant P, it is possible to prevent the occupant P from experiencing motion sickness.

[0070] Regarding (2), in the first image M1, the speed of movement of the water 110 is set to 100 pixels / second. That is, in the first image M1, the speed of movement of the water 110 is set to a speed that reproduces the speed of movement of water that is often seen in the real world. In this way, compared to when an image of the water 110 moving at a speed that deviates from the speed of movement of water in the real world is presented, the occupant P does not feel uncomfortable and stress is reduced, thereby reducing the likelihood of motion sickness in the occupant P.

[0071] Regarding (3), in the first image M1, as the water 110 moves in the lower right direction indicated by the arrow C1 in FIG. 4 , the proportion of the water 110 within the river region A1 increases. In other words, the first image M1 is an image that gives the occupant P a visual effect as if the water 110 is flowing from the back to the front of the screen of the display device 13 as the water 110 moves in the lower right direction. In other words, the first image M1 is an image that gives the occupant P a visual effect as if the object, the water 110, is moving backward (toward the occupant P) as indicated by the arrow D2 in FIG. 1 . In this way, by presenting the occupant P with an image of an object (water 110) moving in a direction (forward and backward) along the traveling direction (forward) of the vehicle 10, the occupant P's physical sensations and his / her visual perception coincide, preventing the occupant P from feeling uncomfortable. As a result, the occupant P's motion sickness can be reduced.

[0072] Furthermore, since the first image M1 showing the water 110 flowing in the opposite direction (rearward) to the traveling direction (forward) of the moving body 10 is presented to the occupant P, the physical sensations and vision of the occupant P more accurately match. As a result, the occupant P is more reliably prevented from feeling discomfort and from experiencing motion sickness.

[0073] Regarding (4), in the first image M1, the movement speed of the sun 120 is set to 10 pixels / second, and the movement speed of the leaves 130 is set to 10 pixels / second. As described above, the movement speed of the water 110 is set to 100 pixels / second. That is, in the first image M1, the movement speed of the water 110, an object located in the lower portion S1, is faster than the movement speeds of the sun 120 and the leaves 130, other objects located in the upper portion S2. In this way, the first image M1 reproduces a scene often seen in the real world, in which a fast-moving object is located in the lower portion and a slow-moving object is located in the upper portion. Therefore, the first image M1 can be said to be an image that does not cause discomfort to the occupant P and is unlikely to cause stress to the occupant P. By presenting such a first image M1 to the occupant P, it is possible to prevent the occupant P from experiencing motion sickness. The above-described speed settings are merely examples, and the movement speed of the water 110 may be set within a range of 100 pix / s to 3500 pix / s, and the movement speeds of the sun 120 and the leaves 130 may be set within a range of 5 pix / s to 99 pix / s. However, from the perspective of suppressing motion sickness in the occupant P, it is preferable to maintain the condition that the movement speed of the object, the water 110, located in the lower portion S1 is faster than the movement speed of the other objects, the sun 120 and the leaves 130, located in the upper portion S2.

[0074] In step S106, the content control unit 433 generates a video playback signal for playing the video shown in Fig. 4. Also in step S106, the content control unit 433 generates an audio playback signal for outputting audio, such as background music, to the speaker 14 in synchronization with the video. Furthermore, in step S106, the content control unit 433 generates a lighting control signal for controlling a lighting pattern to be output together with the video.

[0075] In step S107, the communication interface 41 sends the video playback signal to the video control unit 434. The video control unit 434, having received the signal, controls the display device 13 to play the video shown in FIG. 4. Also in step S107, the communication interface 41 sends the sound playback signal to the audio control unit 435. The audio control unit 435, having received the sound playback signal, controls the speaker 14 to play background music in synchronization with the video. Furthermore, in step S107, the communication interface 41 sends the lighting control signal to the lighting control unit 436. The lighting control unit 436, having received the lighting control signal, controls the lighting device 15 to output a predetermined lighting pattern.

[0076] In step S108, the determination unit 432 determines whether the mobile object 10 has arrived at the destination. For example, if the location information of the destination previously input into the car navigation device 30 matches the location information of the current location of the mobile object 10, the determination unit 432 determines that the mobile object 10 has arrived at the destination. Conversely, if the location information of the destination does not match the location information of the current location of the mobile object 10, the determination unit 432 determines that the mobile object 10 has not arrived at the destination.

[0077] If the moving object 10 has arrived at the destination (Yes in step S108), the processing of the moving object 10 ends. If the moving object 10 has not arrived at the destination (No in step S108), the processing returns to step S102, and the processing from step S102 to step S108 is repeated.

[0078] As described above, in the mobile body 10 to which the playback device 40 according to this embodiment is applied, when the traveling state of the mobile body 10 satisfies the first condition, the content control unit 433 causes the display device 13 to play back video in which the sickness prevention condition for suppressing motion sickness is satisfied. Here, the sickness prevention condition is satisfied by at least one of the arrangement of an area including an object, the moving speed of the object, and the moving direction of the object, and is not achieved by focusing the attention of the occupant P on one point and fixing their vision. Therefore, the above configuration can suppress motion sickness in the occupant P.

[0079] Furthermore, in the moving body 10 to which the playback device 40 according to the present embodiment is applied, the object moves in a direction corresponding to the traveling direction of the moving body 10. Specifically, when the moving body 10 moves forward, the content control unit 433 according to the present embodiment causes the display device 13 to play back the first video M1 in which the proportion of the water 110 in the river region A1 increases as the water 110 moves in a lower right direction (an example of an up-and-down direction) within the river region A1. In this way, the first video M1 is presented that gives the visual effect of the water 110 moving backward (toward the occupant P). In other words, visual information that does not match the occupant P's physical sensations is prevented from being presented to the occupant P. As a result, it is possible to prevent the occupant P from experiencing motion sickness.

[0080] Furthermore, in this embodiment, the first image M1 is presented, in which the object (water 110) is moving in the opposite direction (rearward) of the traveling direction (forward) of the moving body 10. This allows the occupant P's physical sensations and vision to accurately coincide. This more reliably prevents the occupant P from feeling uncomfortable and from experiencing motion sickness.

[0081] (Embodiment 2) In embodiment 2, video that has been subjected to speed adjustment processing is played back. Fig. 5 is a block diagram showing an example of the configuration of a moving body 10A according to embodiment 2. Note that in embodiment 2, components that are substantially the same as those in embodiment 1 are given the same reference numerals, and descriptions thereof will be omitted.

[0082] The central processing unit 43A of the playback device 40A according to the second embodiment can further function as a speed adjustment unit 437 by operating in accordance with the control program stored in the memory 42.

[0083] The speed adjustment unit 437 performs a speed adjustment process to make the moving speed of the object relatively faster than the moving speed of another object. Specifically, the speed adjustment unit 437 makes the moving speed of the object faster than the moving speed of another object. As described above, a video in which the moving speed of an object moving within an area located in the lower part of the video is set faster than the moving speed of another object moving within another area located in the upper part of the video is a video that reproduces a scene from the real world and is capable of suppressing motion sickness in the occupant P. However, the video database 421 may contain videos in which the moving speed of another object is faster than the moving speed of the object. The speed adjustment unit 437 performs the above speed adjustment process on such videos. In this way, a video in which the moving speed of an object is set faster than the moving speed of another object can be generated.

[0084] The speed adjustment process may be a process of making the moving speed of another object slower than the moving speed of the object.

[0085] The speed adjustment process may also be a process of making only the upper part of the video still.

[0086] Furthermore, even if the moving speed of an object moving within an area located in the lower part of the video is set to be faster than the moving speed of another object moving within another area located in the upper part of the video, if the moving speed of the object does not satisfy the sickness suppression condition (2), that is, if the moving speed of the object is not set within the range of 100 pixel / s to 3500 pixel / s, an adjustment process may be performed to speed up or slow down the moving speed of the object so as to satisfy condition (2).In this case, the playback speed of the entire video may be increased or decreased to adjust the moving speed of the object so as to satisfy condition (2).

[0087] In the second embodiment, the video control unit 434 causes the display device 13 to play back the video that has undergone the speed adjustment process.

[0088] According to the playback device 40A of the second embodiment, the speed adjustment unit 437 performs a speed adjustment process, thereby generating a video in which an object located in a lower portion of the video moves faster than another object located in an upper portion of the video. In other words, it is possible to generate a video that reproduces scenes often seen in the real world and is less likely to cause stress to the occupant P. Furthermore, the playback device 40A presents the video generated by the above-described speed adjustment process to the occupant P, thereby preventing the occupant P from experiencing motion sickness.

[0089] The present disclosure can employ the following modifications.

[0090] (Modification)

[0091] (1) In the first embodiment, an example was described in which an image of flowing river water as shown in Fig. 4 was played back on the display device 13. However, as long as any of the above-described motion sickness prevention conditions (1) to (3) is satisfied, the image played back on the display device 13 is not limited to that shown in Fig. 4. Therefore, for example, the display device 13 may play back an image of a beach having an area in which the sea is reflected and in which objects called waves move within the area, an image having an area in which the sky is reflected and in which objects called clouds move within the area, an image having an area in which trees are reflected and in which objects called sunlight filtering through the trees move within the area, or the like.

[0092] (2) The video played on the display device 13 may further satisfy any of the following additional conditions (I) to (III): (I) The video has a fixed viewpoint and angle of view. (II) No artificial objects are included. (III) Objects move linearly.

[0093] Regarding (I), when playing back video with an unfixed viewpoint and angle of view, that is, when playing back video with a frequently changing viewpoint and angle of view, the physical sensations and vision of the occupant P seated in the seat 12 will no longer match, causing discomfort to the occupant P, and the resulting stress may cause motion sickness to the occupant P. In contrast, when the additional condition of (I) is met, the mismatch between the physical sensations and vision of the occupant P can be reduced, thereby preventing the occupant P from experiencing motion sickness.

[0094] Regarding (II), if an artificial object appears in the image, there is a risk that the occupant P's gaze will be focused on the artificial object. In this case, even though the occupant P's body is shaking due to the vibration of the moving body 10, the occupant P's gaze will be fixed at one point, causing a mismatch between the occupant P's physical sensations and his or her vision. This may cause the occupant P to experience motion sickness. In contrast, if the additional condition of (II) is met, that is, if no artificial object appears in the image, the occupant P's gaze will be prevented from being focused on the artificial object, thereby preventing the occupant P from experiencing motion sickness. Examples of artificial objects include buildings such as mountain huts, fields, fishing rods, and beach umbrellas set up on the beach.

[0095] (III) will be described in detail with reference to FIG. 6 . FIG. 6 shows a second image M2, which is an example of an image that satisfies the sickness suppression condition and the additional condition of (III). The second image M2 is an image that shows water flowing from the back of the screen to the front and falling from a waterfall. The second image M2 is played back, for example, when the moving body 10 is moving forward. The second image M2 includes a waterfall area A4, which is an area where a waterfall is displayed. The waterfall area A4 includes water 140, which is an object moving within the waterfall area A4. As indicated by arrow C4 in FIG. 6 , the water 140 moves linearly downward and to the right within the waterfall area A4. In general, the human visual system is sensitive to unpredictable motion, and tends to feel discomfort when the motion is difficult to predict. In other words, if an image including an object moving along a complex trajectory is presented to an occupant P, the occupant P may feel stress associated with discomfort, which may cause motion sickness. In contrast, if an image including an object that moves while maintaining a linear trajectory, such as water 140, is presented to occupant P, it is possible to prevent occupant P from experiencing motion sickness. In other words, if the additional condition (III) is satisfied, it is possible to prevent occupant P from experiencing motion sickness. Note that, as long as occupant P can understand the direction of the flow of water 140, it is not necessary for the edge of second image M2 to be in focus.

[0096] Here, even if some objects do not move linearly within the image, if most of the objects move linearly, the additional condition (III) may be considered to be satisfied. Figure 7 shows a third image M3, which is another example of an image that satisfies the motion sickness prevention condition and the additional condition (III). The third image M3 is an image showing a mountain stream flowing from the back of the screen to the front. The third image M3 is played back, for example, when the moving object 10 is moving forward. The third image M3 includes a mountain stream area A5 in which the mountain stream is displayed. As indicated by arrows C5, C6, and C7 in Figure 7, some objects (water) move along complex trajectories within the mountain stream area A5. However, as indicated by arrow C8 in Figure 7, most objects (water) move linearly within the mountain stream area A5. In other words, in the third video M3, the occupancy rate of the mountain stream area A5 of the objects exhibiting the behavior indicated by the arrow C8 is greater than the occupancy rate of the mountain stream area A5 of the objects exhibiting the behavior indicated by the arrows C5, C6, and C7. Such a third video M3 may be considered to be a video that satisfies the additional condition (III) above.

[0097] (3) In the first embodiment, an example has been described in which the traveling direction sensor 22 provided in the moving body 10 is configured using LIDAR or millimeter-wave radar, but the configuration of the traveling direction sensor 22 is not limited to this. For example, if the moving body 10 is a vehicle equipped with a transmission, the traveling direction sensor 22 may be a sensor that detects the gear position of the transmission. In other words, the traveling direction sensor 22 may be a sensor that detects whether the moving body 10 is set in a forward mode (forward gear) or a reverse mode (reverse gear).

[0098] (4) When the moving body 10 is moving backward, an image may be presented to the occupant P, giving the visual effect of an object moving forward D1 (away from the occupant P). That is, an image may be presented to the occupant P, giving the visual effect of an object moving from the front side to the back side of the screen of the display device 13. Specifically, an image may be presented to the occupant P, in which the proportion of the area occupied by the object decreases as the object moves vertically. Here, "moving backward" of the moving body 10 includes a case in which the occupant P is sitting in a rotating seat of a train or the like and the moving body 10 moves in a direction in which the occupant P is facing away from the moving body 10. In other words, according to the configuration of this modification, an image can be presented to the occupant P, who is seated with his / her back facing the traveling direction of the moving body 10, giving the visual effect of an object moving away from him / her. In this way, an image that more accurately matches the occupant P's physical sensations and vision can be presented to the occupant P, thereby more reliably preventing the occupant P from experiencing motion sickness.

[0099] Whether the moving body 10 is moving in the direction in which the occupant P is facing away from the vehicle 10 may be determined by the determination unit 432. Specifically, the determination unit 432 may determine whether the moving body 10 is moving in the direction in which the occupant P is facing away from the vehicle 10 based on information indicating the traveling direction of the moving body 10 and information indicating the orientation of the occupant P's abdomen and back. The traveling direction of the moving body 10 is acquired by the traveling direction sensor 22 as described above. The orientation of the occupant P's abdomen and back may be acquired by detection means such as a camera built into the display device 13 or a sensor provided in the seat 12.

[0100] (5) When playing back video that satisfies the sickness prevention condition and includes areas related to water, such as a river or ocean, these areas may be positioned in the lower part of the video. Such video faithfully reproduces natural scenery in the real world and does not cause discomfort to the occupant P watching the video, thereby preventing the occupant P from experiencing motion sickness.

[0101] (6) In Fig. 4 of the first embodiment, the reference line L that divides the first image M1 into two equal parts vertically is described, but the position where the reference line L is set is adjustable, and the reference line L does not necessarily have to be set at a position that divides the image into two equal parts vertically. In other words, the reference line L may be set at a position higher than the center of the first image M1 in the vertical direction, or at a position lower than the center of the first image M1 in the vertical direction.

[0102] (7) In FIG. 4 of the first embodiment, an example has been described in which the sun 120 and the leaves 130, which are separate objects, are arranged in the upper portion S2. However, the separate objects are not required. That is, the content control unit 433 may determine to present to the occupant P an image in which only the lower portion of the image changes. Such an image may be interpreted as an example of an image in which the movement speed of an object arranged in the lower portion of the image is faster than the movement speed of another object arranged in the upper portion of the image.

[0103] (8) In the first embodiment, an example was described in which the first condition included at least one of the following: the moving body 10 is moving; and a predetermined time has not elapsed since the moving body 10 stopped.

[0104] Incidentally, if the mobile body 10 is an electric vehicle, a gasoline-powered vehicle, or a bus, for example, and the engine is running even when the mobile body 10 is not moving, the occupant P may sense vibrations caused by the engine operation and may experience motion sickness as a result. Therefore, the first condition may include at least one of the following: the mobile body 10 is moving; a predetermined time has not elapsed since the mobile body 10 came to a stop; and the engine of the mobile body 10 is running.

[0105] Furthermore, depending on the location and conditions under which the mobile body 10 is parked, the occupant P may sense swaying and experience motion sickness even when the mobile body 10 is not moving. Examples of such situations include when the mobile body 10 is parked on a bridge or along a railroad track, or when the mobile body 10 is a ship. Therefore, if the mobile body 10 is equipped with an inertial sensor, the first condition may include at least one of the following: the mobile body 10 is moving; a predetermined time has not elapsed since the mobile body 10 stopped; the engine of the mobile body 10 is running; and the inertial sensor has detected swaying or vibration of the mobile body 10.

[0106] The present disclosure is useful in the technical field of motion sickness suppression.

Claims

1. A playback device provided on a moving body, comprising: an acquisition unit that acquires information regarding the traveling state of the moving body; and a playback unit that causes a display device provided on the moving body to play back one or more videos including at least a part of an area including a moving object. The playback unit plays back the video in which at least one of the arrangement of the area, the moving speed of the object, and the moving direction of the object in the video satisfies a motion sickness suppression condition for suppressing motion sickness of a passenger boarding the moving body when the traveling state satisfies a first condition.

2. The playback device according to claim 1, wherein the first condition includes at least one of the moving body being in motion and a predetermined time not having elapsed since the moving body stopped.

3. The playback device according to claim 1 or 2, wherein the motion sickness suppression condition is that when the video is divided into a lower part and an upper part, the area is arranged in the lower part and the upper part is in a stationary state.

4. In the upper part of the video, there is arranged a different area different from the area, the different area including a different object moving within the different area. The playback unit plays back the video in which the moving speed of the object is faster than the moving speed of the different object.

5. Further, it includes a speed adjustment unit that executes a speed adjustment process for making the moving speed of the object relatively faster than the moving speed of the different object. The playback unit plays back the video on which the speed adjustment process has been performed on the display device.

6. The playback device according to claim 1 or 2, wherein the motion sickness suppression condition is that when the unit of time is 1 second (s) and the unit of the length of the moving distance of the object is 1 pixel (pix), the moving speed of the object is set within the range of 100 pix / s to 3500 pix / s.

7. The playback device according to claim 1 or 2, wherein the motion sickness suppression condition is that the object moves in a direction corresponding to the traveling direction of the moving body.

8. The playback unit according to claim 7, wherein when the moving body moves forward, the playback unit causes the display device to play back the video in which the ratio of the object occupying the area increases as the object moves vertically within the area.

9. The playback unit according to claim 7, wherein when the moving body moves backward, the playback unit causes the display device to play back the video in which the ratio of the object occupying the area decreases as the object moves vertically within the area.

10. A control method for a playback device provided in a moving body, the method comprising: obtaining information regarding the traveling state of the moving body; playing back one or more videos having at least a part of an area including a moving object on a display device provided in the moving body; and in the playback of the video, when the traveling state satisfies a first condition, playing back the video in which at least one of the arrangement of the area in the video, the moving speed of the object, and the moving direction of the object satisfies a motion sickness suppression condition for suppressing motion sickness of a passenger boarding the moving body.

11. An information processing program for a playback device provided in a moving body, the program causing a computer to: obtain information regarding the traveling state of the moving body; play back one or more videos having at least a part of an area including a moving object on a display device provided in the moving body; and in the playback of the video, when the traveling state satisfies a first condition, execute a process of playing back the video in which at least one of the arrangement of the area in the video, the moving speed of the object, and the moving direction of the object satisfies a motion sickness suppression condition for suppressing motion sickness of a passenger boarding the moving body.

Images