JP7619175B2 - CONTROL DEVICE, CONTROL SYSTEM, AND METHOD FOR OPERATION OF CONTROL DEVICE - Google Patents

Description

This disclosure relates to a control device, a control system, and a control method.

Technology has been developed to improve undesirable conditions such as drowsiness of occupants of a moving vehicle by providing stimuli to the occupants. For example, Patent Document 1 discloses a device that prevents occupants from falling asleep by providing a thermal stimulus to the occupant when it is detected that the occupant is falling asleep.

JP 2018-131007 A JP 2008-161664 A JP 2014-012042 A

However, passengers of moving vehicles may suffer from motion sickness. In recent years, various technologies have been developed to prevent, reduce, or eliminate the unpleasant symptoms of motion sickness. With regard to such technologies, there is a demand for technology that can accurately determine whether a passenger has recovered from motion sickness (i.e., whether the motion sickness has been eliminated) after having once become motion sick.

One aspect of the present disclosure aims to accurately determine whether or not motion sickness in a passenger of a moving vehicle has been relieved.

In order to solve the above problem, a control device according to one aspect of the present disclosure includes a biometric information acquisition unit that acquires biometric information of an occupant staying in the interior space of a moving body from a biometric sensor, a sickness determination unit that determines whether the occupant has motion sickness based on the biometric information of the occupant, and a resolution determination unit that determines whether the occupant's motion sickness has been resolved based on the value of an ultra-low frequency component calculated based on the occupant's heart rate measured by a heart rate sensor after it has been determined that the occupant has motion sickness.

One theory is that abnormal activation of the parasympathetic nervous system is one of the causes of motion sickness. It is also said that the value of the infrasonic components of the heart rate is linked to the activity of the sympathetic nervous system.

According to the above configuration, it is determined whether the passenger's motion sickness has been relieved based on the value of the ultra-low frequency component of the heart rate. Therefore, the control device can accurately determine whether the passenger of the moving body has been relieved from motion sickness.

The control device may include an output control unit that controls a stimulating device disposed in the internal space, and the output control unit may cause the stimulating device to start stimulating the occupant when it is determined that the occupant has become motion sick, and may cause the stimulating device to stop stimulating the occupant when it is determined that the occupant's motion sickness has been relieved.

According to the above configuration, if an occupant becomes motion sick, a stimulus can be applied to relieve the motion sickness. Then, when the occupant's motion sickness is relieved, the application of the stimulus can be stopped. This makes it possible to efficiently relieve the occupant's motion sickness.

The stimulation device may be a blower device, and the stimulation to the occupant may be provided by wind blown by the blower device.

The above configuration allows the occupants to effectively relieve motion sickness by blowing air. For example, it is also possible to relieve motion sickness in occupants by using a blower device used for adjusting the air conditioning of a moving vehicle.

The air outlet of the air blowing device may be provided in a neck portion of the seat of the moving body. The output control unit of the control device may adjust at least one of the position and the direction of the air outlet so that the air blown out from the air outlet hits the neck of the occupant.

The surface of a human neck is an area where the skin is exposed. Therefore, when air is blown onto the surface of the neck, a stronger stimulus can be provided compared to blowing air onto other areas under the same conditions. Therefore, with the above configuration, the effect of reducing motion sickness can be enhanced. Specifically, for example, motion sickness can be reduced more quickly. Also, for example, motion sickness can be reduced to a greater extent.

The control device may include a reference value determination unit that determines, as a reference value, the most recent value of the ultra-low frequency component obtained by analyzing the heart rate during a period during which the heart rate is not affected by the application of the stimulus by the stimulus application device, and a comparison value determination unit that determines, as a comparison value, the value of the ultra-low frequency component obtained by analyzing the heart rate during a period during which the heart rate is affected by the application of the stimulus by the stimulus application device, and the resolution determination unit may determine that the motion sickness of the occupant has been resolved when the comparison value is greater than the reference value.

The above configuration makes it possible to more accurately determine whether the passenger's motion sickness has been relieved.

The comparison value determination unit of the control device may determine the comparison value to be the largest value among the values of the ultra-low frequency components obtained by analyzing the heart rate during the period affected by the application of the stimulus.

The above configuration makes it possible to more accurately determine whether the passenger's motion sickness has been relieved.

In order to solve the above problem, a control system according to one embodiment of the present disclosure includes the control device, the biosensor, and the heart rate sensor. With the above configuration, the same effect as the control device is achieved.

In order to solve the above problem, a control method according to one aspect of the present disclosure includes a biometric information acquisition step of acquiring biometric information of an occupant staying in the interior space of a moving body from a biometric sensor, a sickness determination step of determining whether the occupant has motion sickness based on the biometric information of the occupant acquired from the biometric sensor, a calculation step of calculating a value of an ultra-low frequency component of the occupant's heart rate based on the heart rate of the occupant measured by a heart rate sensor, and a resolution determination step of determining whether the occupant's motion sickness has been resolved based on the value of the ultra-low frequency component after it has been determined that the occupant has motion sickness. The above method provides the same effects as the control device.

According to one aspect of the present disclosure, it is possible to accurately determine whether or not a passenger in a moving vehicle has recovered from motion sickness.

1 is a block diagram showing a configuration of a main part of a control system according to the present disclosure. FIG. 1 is a diagram showing an example of installation of a blower device. 11 is a graph visually illustrating an example of a reference value and a comparison value. 13 is a graph visually illustrating another example of the reference value and the comparison value. 5 is a flowchart showing an example of a flow of periodic processing in the control device. 5 is a flowchart showing an example of a process flow relating to motion sickness determination and output control in the control device. 1 is a graph showing the time required for each group to recover from motion sickness, obtained from the test results of Example 1. 1 is a graph showing the time course of the VLF Z-score of the subject's heart rate, obtained as a result of the test in Example 2.

[Embodiment]
The control system according to this embodiment is a system for determining whether or not an occupant staying in the interior space of a moving body is suffering from motion sickness.

The various symptoms of motion sickness are thought to occur due to activation of the parasympathetic nervous system. For example, there is a theory that when sensory information becomes confused, a mismatch signal is generated in the brain, and this mismatch signal causes various motion sickness symptoms due to autonomic nervous dysfunction via the limbic system and hypothalamus (Hirayanagi, 2006, "Current status and future prospects of motion sickness (motion sickness) research," Ergonomics, Vol. 42, No. 3, p. 200-211).

For example, there is a theory that vagus nerve tone increases (i.e., parasympathetic nerve activation) just before the onset of strong nausea caused by motion sickness (LaCount et al., 2010, “Dynamic Cardiovagal Response to Motion Sickness: A Point-Process Heart Rate Variability Study”, Comput Cardiol 2009 January 1; 36: 49-52. and Ishii, 1990, “On Motion Sickness and Fluctuations in the Autonomic Nervous System”, Journal of the Oto-Rhino-Laryngological Society of Japan, Vol. 93, No. 10, p. 1802). It is widely known that there is a trade-off between sympathetic nerve activation and parasympathetic nerve activation.

The inventors of the present disclosure have discovered a new method for determining motion sickness by focusing on the causal relationship between activation of the parasympathetic nervous system and the onset of motion sickness, and the trade-off relationship between the sympathetic nervous system and the parasympathetic nervous system. Specifically, the inventors have discovered a method for determining whether or not motion sickness in a passenger of a moving object has been relieved based on the degree of activity of the passenger's sympathetic nervous system.

The inventors then devised a system that efficiently relieves motion sickness in passengers of a moving vehicle by providing the passenger with a stimulus to relieve the motion sickness when the passenger suffers from motion sickness, and by stopping the provision of the stimulus to the passenger when the passenger's motion sickness is relieved.

Below, an embodiment of the present disclosure will be described with reference to Figures 1 to 6. In the following description, occupants staying in the internal space of a moving body will be referred to simply as "occupants."

<Main components>
1 is a block diagram showing a configuration of a main part of a control system 100. The control system 100 includes a control device 10, a biosensor 20, a storage device 30, and a blower device 40. The control device 10 is connected to the biosensor 20, the storage device 30, and the blower device 40 by wire or wirelessly.

(Mobile object 1)
In this embodiment, the control device 10, the biosensor 20, the storage device 30, and the blower 40 are arranged in the interior space of the moving body 1. The moving body 1 is a moving body having a space inside where a human can stay, such as an automobile, a train, or an airplane. The interior space of the moving body 1 may be provided with one or more seats.

(Biosensor 20)
The biosensor 20 is one or more sensors or a group of sensors that measure or acquire bioinformation of the occupant. In this embodiment, the "biological information" refers to various information for identifying the physical condition of the occupant. For example, the bioinformation may be vital data of the occupant, a still image or video of the occupant, or the occupant's speech. In this embodiment, the biosensor 20 includes at least a heartbeat sensor 21, and the heartbeat signal of the occupant is measured by the heartbeat sensor 21 as the bioinformation.

The placement positions and number of the various biosensors 20, including the heart rate sensor 21, are not particularly limited. For example, the biosensor 20 may be a sensor placed in the interior space of the moving body 1 or in a device provided in the moving body 1. For example, the biosensor 20 may be placed in the armrest of the seat. Also, for example, the biosensor 20 may be a sensor provided in a wearable device worn by the occupant, such as headphones, earphones, or a wristband.

The heart rate sensor 21 measures the occupant's heart rate as a type of biometric information. In this embodiment, the heart rate sensor 21 measures the occupant's heart rate periodically or constantly. The heart rate sensor 21 transmits the measured heart rate as a signal (heart rate signal) to the biometric information acquisition unit 11 of the control device 10 at any time. In other words, the control device 10 uses the heart rate sensor 21 to monitor the occupant's heart rate.

The biosensor 20 may measure or acquire other bioinformation in addition to the heartbeat signal and transmit it to the control device 10. That is, the biosensor 20 may include sensors other than the heartbeat sensor 21. For example, the biosensor 20 may include a vital sensor for measuring vital data such as pulse, respiration, body temperature, blood pressure, consciousness, and reflexes in addition to the heartbeat signal. For example, the biosensor 20 may include a camera that acquires still images and/or videos of the occupant as bioinformation. For example, the biosensor 20 may include a microphone that acquires the occupant's speech. In any case, the various biosensors 20 transmit the measured or acquired bioinformation to the bioinformation acquisition unit 11 of the control device 10.

When there are multiple occupants of the moving body 1, the heart rate sensor 21 measures the heart rate signal of each occupant separately and transmits the heart rate signal of each occupant in a distinguishable state to the control device 10. Similarly, the biosensors 20 other than the heart rate sensor 21 also measure the bioinformation of each occupant separately and transmit the bioinformation of each occupant in a distinguishable state to the control device 10.

For example, the biosensor 20 may be arranged so that the bioinformation of the occupant sitting in each seat can be measured or acquired. When measuring or acquiring the bioinformation, the biosensor 20 may identify which seat the occupant's bioinformation is acquired from. In this case, the biosensor 20 may associate the measured or acquired bioinformation with the identification information of the seat, and then transmit the bioinformation and the identification information to the control device 10. Also, for example, if the biosensor 20 is provided in a wearable device, the biosensor 20 may associate the bioinformation with the identification information of the wearable device, and then transmit the bioinformation and the identification information to the control device 10. With this configuration, the control device 10 that receives the bioinformation can handle the bioinformation of each occupant separately.

(Blower device 40)
The blower device 40 is a device for blowing air (e.g., cool air) toward the occupant. More specifically, the blower device 40 has, for example, an air outlet and a drive mechanism such as a motor for generating air and blowing it from the air outlet. The blower device 40 may be a mechanism that performs part of the function of the moving body 1. For example, the blower device 40 may be an air conditioner (air conditioner) in the moving body 1, and the aforementioned air outlet may be an air outlet of the air conditioner.

The blower device 40 operates according to the control instructions of the output control unit 13. For example, the blower device 40 adjusts at least one of the position and direction of the air outlet according to the control instructions of the output control unit 13. The blower device 40 also blows air from the air outlet toward the occupants in an output mode according to the control instructions of the output control unit 13. For example, the blower device 40 outputs air at a temperature and strength according to the control instructions of the output control unit 13.

Figure 2 is a diagram showing an example of the installation of the blower device 40. In the example of Figure 2, the blower device 40 is provided in the neck portion of the seat. In this manner, the blower device 40 may be provided in the seat. This allows air from the air outlet to be directed at the neck of an occupant when the occupant sits in the seat.

There may be multiple air blowers 40 and air outlets. Also, one air blower 40 may be configured to blow air from multiple air outlets. When there are multiple air outlets, the air blower 40 can adjust the position or direction of each air outlet. Note that the "direction of the air outlet" referred to here may refer to the angle of the fan installed inside the air outlet, or the direction of the air flow path inside the air outlet, in addition to the direction of the entire air outlet.

The seat of the moving body 1 may be provided with various mechanisms, such as a reclining mechanism, to realize the function of the seat of the moving body 1. Furthermore, multiple seats may be provided in the interior space of the moving body 1. If multiple seats are provided, it is desirable that an air outlet of the air blower 40 be provided for each seat. This allows air to be blown individually to the occupants sitting in each seat.

(Control device 10)
The description will be given again with reference to Fig. 1. The control device 10 is a device that controls the air blower 40 based on biological information from the biological sensor 20. The control device 10 includes a biological information acquisition unit 11, a sickness determination unit 12, an output control unit 13, a VLF calculation unit 14, and a relief determination unit 15.

The biometric information acquisition unit 11 acquires biometric information of the occupant from the biometric sensor 20. The biometric information acquisition unit 11 outputs the acquired biometric information to the sickness determination unit 12. In addition, the biometric information acquisition unit 11 outputs the heart rate signal from the acquired biometric information to the VLF calculation unit 14.

When the biometric information acquisition unit 11 acquires biometric information of each occupant from the biometric sensor 20 in a distinguishable state, it outputs the biometric information separately to the sickness determination unit 12 and the VLF calculation unit 14. For example, when the biometric information acquisition unit 11 receives biometric information and identification information of a seat or wearable device associated with the biometric information, it may output the biometric information and the identification information to the sickness determination unit 12 and the VLF calculation unit 14 with the association intact.

The biometric information acquisition unit 11 outputs the heart rate signal received from the heart rate sensor 21 of the biometric sensor 20 to the VLF calculation unit 14 at any time. On the other hand, the timing of outputting the biometric information from the biometric information acquisition unit 11 to the sickness determination unit 12 is not particularly limited. For example, the biometric information acquisition unit 11 may supply the biometric information to the sickness determination unit 12 in accordance with the execution cycle of the sickness determination in the sickness determination unit 12.

The sickness determination unit 12 determines whether or not the occupant is in a state of motion sickness based on the biometric information input from the biometric information acquisition unit 11. The sickness determination unit 12 outputs the determination result to the output control unit 13. The sickness determination unit 12 may perform a determination each time biometric information is input from the biometric information acquisition unit 11 to the sickness determination unit 12.

As long as it is possible to determine whether or not an occupant is in a state of motion sickness, the method of determination in the sickness determination unit 12 is not particularly limited. For example, the sickness determination unit 12 may refer to biometric information indicating the facial expression or gestures of the occupant, such as an image captured by a camera as the biometric sensor 20. Then, based on the biometric information, the sickness determination unit 12 may determine whether or not the occupant is in a state of motion sickness by analyzing whether or not the occupant has a facial expression or gestures that are characteristic of a state of motion sickness. Also, for example, the sickness determination unit 12 may determine whether or not the occupant is in a state of motion sickness by estimating the physical condition of the occupant from the vital data of the occupant.

The sickness determination unit 12 may determine whether or not the occupant is in a state of motion sickness by calculating an index value indicating the intensity of motion sickness. More specifically, the sickness determination unit 12 may calculate a "sickness level" as the aforementioned index value, for example. The classification of the sickness level is determined appropriately. For example, the sickness determination unit 12 calculates the sickness level of the occupant into five levels, from level 0 to level 4.

When calculating the sickness level, the sickness determination unit 12 determines whether the calculated sickness level value is equal to or greater than a predetermined first threshold. If the sickness level is equal to or greater than the first threshold, the sickness determination unit 12 determines that the occupant is in a state of motion sickness. If the sickness level is less than the first threshold, the sickness determination unit 12 determines that the occupant is not in a state of motion sickness. The specific numerical value of the first threshold is not particularly limited, but in this embodiment, the first threshold is a value greater than 0.

When there are multiple occupants, the sickness determination unit 12 determines whether each occupant is in a state of motion sickness individually based on the biometric information of each occupant. For example, when the sickness determination unit 12 acquires information in which biometric information is associated with an identification number of a seat or a wearable device, it may perform a determination of whether each identification number is in a state of motion sickness individually.

The output control unit 13 controls the air blower 40 according to the judgment results of the sickness judgment unit 12 and the resolution judgment unit 15. Specifically, when the sickness judgment unit 12 judges that a certain occupant is in a state of motion sickness, the output control unit 13 controls the air blower 40 to blow air to the occupant. In addition, when the resolution judgment unit 15 judges that a certain occupant's motion sickness has been resolved, the output control unit 13 controls the air blower 40 to stop blowing air to the occupant.

Note that the output control unit 13 according to the present disclosure may control the blower device 40 so that the wind hits the occupant with irregular strength. Here, "blows hitting the occupant with irregular strength" means, for example, blowing out wind by switching the wind output strength between two or more levels randomly or regularly. Note that controlling the output strength also includes setting the output to zero, i.e., not blowing air. Note that in the present disclosure, stopping the wind intermittently while blowing air is not included in the processing operations of "stopping the blowing of air" and "terminating the blowing of air." In the present disclosure, stopping (or terminating) the blowing of air means stopping (terminating) the operation related to the blowing of air itself, including intermittent blowing of air.

The output control unit 13 may physically open and close the air outlet of the air blower 40 to achieve air blowing with irregular strength to the occupants. The output control unit 13 may also move the direction of the air outlet over time to achieve air blowing with irregular strength to the occupants. The output control unit 13 may also control the temperature of the air blown from the air outlet of the air blower 40.

For example, the output control unit 13 may instruct the blower device 40 to intermittently switch between two levels of output intensity: with air blowing and without air blowing. This allows the occupant to be repeatedly stimulated by the environmental change when going from a no-air state to an air blowing state, and when going from an air blowing state to a no-air state. This allows the occupant to be stimulated more efficiently. In addition, since the above-mentioned two types of environmental change stimuli occur alternately, it is difficult for the occupant to become accustomed to these stimuli. This therefore increases the effect of reducing motion sickness compared to when air is constantly blown.

The output control unit 13 may also refer to the output pattern information 32 stored in the storage device 30 to determine the output intensity switching pattern for the air blower 40. Hereinafter, the output intensity switching pattern is also referred to as the "output pattern." The output pattern may include information indicating the temperature of the air blown out from the air outlet. The output pattern may also include information indicating the pattern of temperature change of the air blown out from the air outlet.

When the sickness level is input from the sickness determination unit 12 to the output control unit 13, the output control unit 13 may determine an output pattern according to the sickness level. Then, the output control unit 13 may cause the blower device 40 to blow air in an output pattern according to the sickness level.

For example, if an occupant is very sick, i.e., if the occupant has severe motion sickness, it is desirable to provide the occupant with a strong stimulus to quickly relieve the motion sickness. For this reason, the output control unit 13 may, for example, increase the wind speed or increase the drop in output strength the higher the level of sickness. This makes it possible to blow air to the occupant in an output mode that is more effective in reducing motion sickness.

The VLF calculation unit 14 calculates the amplitude spectrum power value of the very low frequency (VLF) component of the cardiac cycle by analyzing the cardiac signal input from the bioinformation acquisition unit 11. In the following description, the "amplitude spectrum power value of the very low frequency component of the cardiac cycle" is simply referred to as the "VLF value."

A conventional method may be used to calculate the VLF value. The VLF calculation unit 14 records the calculated VLF value in the VLF data 31 of the storage device 30. In other words, the VLF calculation unit 14 adds the latest VLF value to the VLF data 31.

In order to calculate the VLF value of a particular occupant, it is necessary to analyze the heart rate signal of that occupant for a certain period of time. Therefore, the VLF calculation unit 14 temporarily stores the heart rate signal input from the bioinformation acquisition unit 11 at any time for a predetermined period of time, and periodically analyzes the temporarily stored heart rate signal data. This allows the VLF calculation unit 14 to periodically calculate the VLF value. Note that the aforementioned "predetermined period" is not particularly limited to a specific value, so long as it is a period during which the VLF value can be calculated. For example, the predetermined period may be approximately 60 seconds.

In addition, the control device 10 of this embodiment may regard the VLF value calculated based on the stored heart rate signal for a predetermined period as the occupant's "current VLF value" or as "the VLF value at a certain point in the past."

To explain more specifically, for example, the bioinformation acquisition unit 11 stores heartbeat signal data for the past 60 seconds. In this case, the control device 10 may regard the VLF value calculated based on the heartbeat signal from 60 seconds ago to the present (i.e., 0 seconds ago) as the "current VLF value obtained by analyzing the heartbeat signal for the past 60 seconds."

Alternatively, the control device 10 may regard the VLF value calculated based on the heart rate signal from 60 seconds ago to the present as the "VLE value from 30 seconds ago obtained by analyzing the heart rate signal for 30 seconds before and after the point 30 seconds ago." This is because the fact that the bioinformation acquisition unit 11 stores the heart rate signal for the past 60 seconds also means that, if a point 30 seconds before the present is taken as a fixed point, the bioinformation acquisition unit 11 stores the heart rate signal for 30 seconds before and after the fixed point.

In this embodiment, unless otherwise specified, the biometric information acquisition unit 11 temporarily stores the heart rate signal for the past 60 seconds. Also, in this embodiment, unless otherwise specified, the control device 10 regards the VLF value calculated based on the heart rate signal from 60 seconds ago to the present as the "current VLF value."

The resolution determination unit 15 determines whether the occupant's motion sickness has been resolved by blowing air. Hereinafter, the determination of whether motion sickness has been resolved is also referred to as a "resolution determination." In other words, the resolution determination unit 15 performs a resolution determination for an occupant who has been determined by the sickness determination unit 12 to be "in a state of motion sickness."

The resolution determination unit 15 includes a reference value determination unit 151, a comparison value determination unit 152, and a comparison unit 153. The resolution determination unit 15 reads out the VLF data 31, and performs preprocessing for resolution determination in the reference value determination unit 151 and the comparison value determination unit 152. Thereafter, the resolution determination unit 15 performs resolution determination in the comparison unit 153.

The reference value determination unit 151 determines a reference value from the VLF value recorded in the VLF data 31. The "reference value" refers to a standard VLF value for a certain occupant when that occupant is in a state of motion sickness. In this embodiment, the reference value determination unit 151 determines the most recent VLF value among the VLF values obtained by analyzing the heart rate during a period when the occupant is not affected by the air blowing device 40 as the reference value. The method of determining the reference value will be described in detail later. The reference value determination unit 151 outputs the determined reference value to the comparison unit 153. Note that when there are multiple occupants, the reference value determination unit 151 determines the reference value for each occupant separately.

The comparison value determination unit 152 determines the comparison value from the VLF value recorded in the VLF data 31. The "comparison value" refers to the VLF value when a certain occupant is given a stimulus (in this embodiment, air blowing) to relieve motion sickness. In this embodiment, the comparison value determination unit 152 determines the maximum VLF value obtained by analyzing the heart rate during the period when the occupant is affected by the air blowing device 40 as the comparison value. The method of determining the comparison value will be described in detail later. The comparison value determination unit 152 outputs the determined comparison value to the comparison unit 153. Note that, when the comparison value cannot be determined, for example, immediately after the start of air blowing, the comparison value determination unit 152 may determine the comparison value to be 0, or may notify the comparison unit 153 that the comparison value cannot be determined. In addition, when there are multiple occupants, the comparison value determination unit 152 determines the comparison value for each occupant separately.

The comparison unit 153 performs a resolution determination based on the reference value and the comparison value. More specifically, the comparison unit 153 determines whether the comparison value input from the comparison value determination unit 152 is greater than the reference value input from the reference value determination unit 151. If the comparison value is greater than the reference value, the comparison unit 153 determines that the occupant's motion sickness has been resolved. If the comparison value is equal to or less than the reference value, the comparison unit 153 determines that the occupant's motion sickness has not been resolved.

When the comparison value determination unit 152 is unable to determine the comparison value, such as immediately after the start of air blowing, the comparison unit 153 may perform a resolution determination assuming the comparison value to be 0. In addition, when there are multiple occupants, the comparison unit 153 performs a resolution determination for each occupant based on the reference value and comparison value for each occupant.

When the comparison unit 153 determines that the occupant's motion sickness has been resolved, the resolution determination unit 15 notifies the output control unit 13 that the occupant's motion sickness has been resolved. Note that when there are multiple occupants, the resolution determination unit 15 also notifies the output control unit 13 of which occupant's motion sickness has been resolved.

It is generally known that the VLF value fluctuates depending on factors such as the occupant's state and behavior, such as activity, rest, sleep, and wakefulness, as well as the occupant's internal circadian rhythm. Therefore, if a resolution determination is made based on the magnitude of the VLF value itself, there is a risk that a sufficiently accurate determination will not be obtained.

In response to this, the reference value determination unit 151, as described above, determines the most recent VLF value among the VLF values obtained by analyzing the heart rate during the period when the heart rate is not affected by the air blowing as the reference value. The comparison unit 153 then compares the reference value with the VLF value obtained by analyzing the heart rate during the period when the heart rate is affected by the air blowing (in this embodiment, the maximum value during that period) to determine whether or not the motion sickness has been resolved. Therefore, according to the resolution determination in this embodiment, an accurate determination result can be obtained even if the VLF value itself fluctuates due to the occupant's state, behavior, circadian rhythm, etc. Therefore, the resolution determination unit 15 can accurately determine whether or not the occupant is in a state of motion sickness.

(Storage device 30)
The storage device 30 stores various data necessary for the operation of the control device 10. The storage device 30 stores, for example, VLF data 31 and output pattern information 32. If the control system 100 does not include the storage device 30, the various data stored in the storage device 30 may be stored in an internal memory (not shown) of the control device 10.

The VLF data 31 is data that records the VLF values of the occupants in chronological order. When there are multiple occupants, the VLF data 31 is stored for each occupant. The VLF data 31 is updated by the VLF calculation unit 14 and read by the resolution determination unit 15.

The output pattern information 32 is data that specifies the output mode of the blower device 40. Note that the "output mode" referred to here indicates, for example, the output intensity, the time the output is on, the time the output is off, and the timing of turning the output on and off. Note that the output pattern information 32 may be data that specifies the output mode for each intensity of the occupant's motion sickness (for example, the aforementioned sickness level).

<Reference value and comparison value>
Next, a method for determining the reference value and the comparison value will be described in more detail with reference to Figures 3 and 4. In the following description, it is assumed that the VLF calculation unit 14 calculates the VLF value at one-second intervals and records it in the VLF data 31. That is, for the sake of convenience, the VLF values are shown as lines rather than dots in the graphs of Figures 3 and 4, but in reality, these lines are a collection of points on which the VLF values for each second are plotted.

Figure 3 is a graph visually showing an example of the reference value and the comparison value. In Figure 3, a method for determining the reference value and the comparison value and a resolution determination are explained when the control device 10 regards the VLF value calculated based on the heart rate signal from 60 seconds ago to the present as the "current VLE value."

The graph at the top of Figure 3 is a graph showing VLF data 31 at time t1 when air supply to the occupant begins. In the example of Figure 3, the VLF value calculated at time t1 is considered to be the current VLF value (i.e., at time t1). At time t1, all plots in the graph are "VLF values obtained by analyzing heart rates during a period not affected by air supply." Therefore, the reference value determination unit 151 determines the most recent VLF value in the graph, i.e., the VLF value at time t1, to be the reference value.

In addition, at time t1, the "VLF value obtained by analyzing the heart rate during the period when it is affected by the air blowing" does not exist in the graph. Therefore, the comparison value determination unit 152 considers the comparison value to be 0. Alternatively, the comparison value determination unit 152 notifies the resolution determination unit 15 that the comparison value cannot be calculated. In this way, since the reference value is greater than the comparison value at time t1, the resolution determination unit 15 determines that "the occupant's motion sickness has not been resolved" at time t1.

The graph in the middle of Figure 3 shows the VLF data 31 at time t2 after air supply to the occupant has started. Because air supply is continuing at time t2, the reference value is the same as at time t1. At time t2, the "VLF value obtained by analyzing the heart rate during the period when air supply is applied" is the VLF value in the section of the gray dotted portion in the graph. The comparison value determination unit 152, for example, determines the maximum value of the VLF values in the section of the gray dotted portion as the comparison value. As shown, at time t2, the reference value > the comparison value. Therefore, even at time t2, the resolution determination unit 15 determines that "the occupant's motion sickness has not been resolved."

The graph at the bottom of FIG. 3 shows VLF data 31 at time t3, which is after t2 and after air supply to the occupant has started. Because air supply is still continuing at time t3, the reference value is the same as at time t1. The VLF value in the section of the gray dotted portion in the graph at the bottom of FIG. 3 is the "VLF value obtained by analyzing the heart rate during the period when air supply is affected" at time t3. As with time t2, the comparison value determination unit 152 determines the maximum value of the VLF values in the section of the gray dotted portion as the comparison value. As shown, at time t3, the reference value is less than the comparison value. Therefore, at time t3, the resolution determination unit 15 determines that "the occupant's motion sickness has been resolved."

Figure 4 is a graph visually showing another example of the reference value and the comparison value. In Figure 4, a method of determining the reference value and the comparison value and a resolution determination are explained when the control device 10 regards the VLF value calculated based on the heartbeat signal for 60 seconds from 60 seconds ago to the present as the "VLF value of a fixed point (i.e., a point 30 seconds ago from the present) obtained by analyzing the heartbeat signal for 30 seconds before and after the fixed point."

The upper graph in Figure 4 shows the VLF data 31 at time t4, when air supply to the occupants began. As mentioned above, in the example of Figure 4, the VLF value calculated at time t4 is considered to be the "VLF value 30 seconds ago (t4-30)."

In the example of Figure 4, the VLF value from 30 seconds before the present is calculated sequentially. Therefore, at time t4, all plots in the graph are "VLF values obtained by analyzing the heart rate during a period not affected by airflow." Therefore, the reference value determination unit 151 determines the most recent VLF value in the graph, i.e., the VLF value at time "t4-30," to be the reference value.

In addition, at time t4, the "VLF value obtained by analyzing the heart rate during the period when the vehicle is affected by the air blowing" does not exist in the graph. Therefore, the comparison value determination unit 152 considers the comparison value to be 0. Alternatively, the comparison value determination unit 152 notifies the resolution determination unit 15 that the comparison value cannot be calculated. In this way, since the reference value is greater than the comparison value at time t4, the resolution determination unit 15 determines that "the occupant's motion sickness has not been resolved."

The graph in the middle of Figure 4 shows VLF data 31 at time t5 after air supply to the occupant has started. Because air supply is continuing at time t5, the reference value is the same as at time t4 (VLF value at time t4-30). At time t5, the "VLF value obtained by analyzing the heart rate during the period when air supply is applied" is the VLF value in the gray shaded area in the graph. The comparison value determination unit 152, for example, determines the maximum value of the VLF values in the gray shaded area as the comparison value. As shown, at time t5, the reference value is greater than the comparison value. Therefore, even at time t5, the resolution determination unit 15 determines that "the occupant's motion sickness has not been resolved."

The graph at the bottom of FIG. 4 shows VLF data 31 at time t6, which is after t5 and after airflow to the occupant has started. Because airflow continues at time t6, the reference value is the same as at time t4. The VLF value in the gray shaded area in the graph at the bottom of FIG. 4 is the "VLF value obtained by analyzing the heart rate during the period when airflow is applied" at time t6. As with time t2, the comparison value determination unit 152 determines the maximum value of the VLF values in the gray shaded area as the comparison value. As shown, at time t6, the reference value is less than the comparison value. Therefore, at time t6, the resolution determination unit 15 determines that "the occupant's motion sickness has been resolved."

In this way, even if the calculation method of the VLF value is different, the calculation procedure of the reference value and the comparison value, and the method of the resolution determination may be the same. In the example of FIG. 4, the resolution determination is made based on the VLF value from the present to 30 seconds ago, but the resolution determination unit 15 may take the determination result as the "determination result from 30 seconds ago" or the "current determination result."

(Periodic processing)
In the control device 10, the acquisition of the heart rate signal by the biological information acquisition unit 11, the calculation of the VLH value, and the recording of the VLH value in the VLF data 31 are periodic processes that are periodically executed regardless of whether the occupant is suffering from motion sickness. Fig. 5 is a flowchart showing an example of the flow of the periodic processes in the control device 10.

As described above, the biometric information acquisition unit 11 of the control device 10 receives a heart rate signal from the heart rate sensor 21 (S11). The biometric information acquisition unit 11 outputs the acquired heart rate signal to the VLF calculation unit 14 (and the sickness determination unit 12).

The VLF calculation unit 14 temporarily stores the heartbeat signal input from the bioinformation acquisition unit 11 at any time for a predetermined period. The VLF calculation unit 14 calculates the VLF value based on the heartbeat signal for this predetermined period (S12). The VLF calculation unit 14 stores the calculated VLF value in the storage device 30 as VLF data 31 (S13). As a result, the latest VLF value is recorded in chronological order in the VLF data 31.

The control device 10 executes the periodic processing shown in FIG. 5 at a predetermined time interval. As a result, the VLF values of the occupants are recorded in the VLF data 31 at a predetermined time interval. For example, if the execution interval of the periodic processing is one second, the VLF value for each second is recorded in the VLF data 31. The control device 10 also executes the periodic processing shown in FIG. 3 for each occupant. As a result, the VLF value for each occupant is recorded in the VLF data 31.

<Processing flow>
Finally, a description will be given of the relationship between the determination of motion sickness in the control device 10 and the output control for the blower device 40. Fig. 6 is a flowchart showing an example of the flow of processing related to the determination of motion sickness and output control in the control device 10.

When a person gets into the vehicle 1, the biosensor 20 detects the presence of the occupant and measures or acquires bioinformation. The biosensor 20 transmits the bioinformation to the bioinformation acquisition unit 11 of the control device 10. This includes the heart rate signal measured by the heart rate sensor 21.

The biometric information acquisition unit 11 periodically receives biometric information from various biometric sensors 20. The biometric information acquisition unit 11 outputs the acquired biometric information to the sickness determination unit 12 and the VLF calculation unit 14.

The sickness determination unit 12 determines whether the occupant has motion sickness based on the biometric information (S21). If it is determined that the occupant does not have motion sickness (NO in S22), the sickness determination unit 12 does not give any particular instruction to the output control unit 13, and the control device 10 waits until the next biometric information is acquired from the biometric sensor 20. On the other hand, if it is determined that the occupant has motion sickness (YES in S22), the sickness determination unit 12 outputs the determination result to the output control unit 13. Then, the output control unit 13 controls the air blower 40 to start blowing air to the occupant (S23). The output control unit 13 may inform the resolution determination unit 15 that air blowing has started.

After the air supply starts, that is, after the sickness determination unit 12 determines that the occupant has motion sickness, the resolution determination unit 15 reads out the VLF data 31 that is recorded at any time by regular processing. Then, the reference value determination unit 151 of the resolution determination unit 15 determines a reference value based on the VLF data 31 (S24). Next, the comparison value determination unit 152 determines a comparison value based on the VLF data 31 (S25). Then, the comparison unit 153 compares the determined reference value with the comparison value.

If the comparison value is greater than the reference value (YES in S26), the resolution determination unit 15 determines that the occupant's motion sickness has been resolved (S27) and outputs the determination result to the output control unit 13. The output control unit 13 controls the air blower 40 to end the blowing of air to the occupant (S28). The output control unit 13 may also inform the sickness determination unit 12 that the blowing of air has been ended.

On the other hand, if the comparison value is equal to or less than the reference value (NO in S26), the resolution determination unit 15 determines that the occupant's motion sickness has not been resolved (S29). The resolution determination unit 15 then reads new VLF data 31 and repeats the process from S25.

As mentioned above, the latest VLF value is recorded in the VLF data 31 through periodic processing. Therefore, the resolution determination unit 15 can retry the determination from S25, including the latest VLF value, by re-reading the VLF data 31.

As described above, when there are multiple occupants, the resolution determination unit 15 performs a resolution determination for each occupant based on the reference value and comparison value determined for each occupant. Therefore, the resolution determination by the resolution determination unit 15 is performed periodically until the air blower 40 stops blowing air to a certain occupant. The interval at which the resolution determination is performed for a certain occupant is not particularly limited. For example, the resolution determination unit 15 may perform the resolution determination for a certain occupant at the same cycle as the calculation cycle of the VLF value by the VLF calculation unit 14.

According to the process shown in FIG. 6, it is determined whether the occupant's motion sickness has been resolved based on the VLF value. More specifically, the control device 10 sets a reference value for the VLF value when the occupant is in a state of motion sickness, and after blowing air, it is determined whether the VLF value has increased from that reference value. In this way, according to the process shown in FIG. 6, the comparison is made with a certain occupant's own "VLF value when motion sick," so it is possible to reduce the influence on the resolution determination of the occupant's current behavior, the occupant's physical condition, exit from the vehicle, and the environment (temperature, etc.) of the internal space of the vehicle 1. Therefore, the control device 10 can accurately determine whether the occupant's motion sickness has been resolved.

[Modifications]
(Modifications of the control system 100)
In the control system 100 according to the present disclosure, the storage device 30 may be an internal memory of the control device 10. Furthermore, the control system 100 according to the present disclosure may include a stimulating device for stimulating an occupant other than the blower device 40. For example, the seat of the moving body 1 may be provided with an element that provides a warm or cold sensation to the occupant in each seat as the stimulating device.

(Modification of Calculation of VLF Value)
The bioinformation acquisition unit 11 according to the present disclosure may acquire the VLF value from the heart rate sensor 21. In this case, the heart rate sensor 21 measures the heart rate of the occupant and temporarily stores the heart rate data for a predetermined period. Then, the VLF value is calculated based on the heart rate data for the predetermined period. The method of calculating the VLF value may be the same as the method described in the explanation of the bioinformation acquisition unit 11. The heart rate sensor 21 transmits the calculated VLF value to the bioinformation acquisition unit 11. Upon receiving the VLF value, the bioinformation acquisition unit 11 outputs the VLF value to the VLF calculation unit 14 (and the sickness determination unit 12).

(Modifications of the Reference Value and the Comparison Value)
The reference value determination unit 151 may determine the reference value by a method other than the method described in the above embodiment. Also, the comparison value determination unit 152 may determine the comparison value by a method other than the method described in the above embodiment.

For example, the reference value determination unit 151 may determine the average value of the VLF values calculated from the heart rate during a period not affected by air blowing for a specified period of time immediately preceding the reference value, and may set the average value as the reference value. Also, for example, the comparison value determination unit 152 may set the average value of the VLF values calculated from the heart rate during a period affected by air blowing as the comparison value.

(Modification of Resolution Judgment)
In the above embodiment, the resolution determination unit 15 determines that "the motion sickness of the occupant has been resolved" once the comparison unit 153 determines that "the comparison value is greater than the reference value." However, the resolution determination unit 15 according to the present disclosure may make a final resolution determination result based on the results of the comparison unit 153 making a comparison determination of values multiple times.

For example, the resolution determination unit 15 may determine that the occupant's motion sickness has been resolved when the comparison unit 153 determines that "the comparison value is greater than the reference value" a predetermined number of times in succession. This allows the criterion for resolution determination to be adjusted by changing the setting of the aforementioned predetermined number of times. For example, the higher the aforementioned predetermined number of times is set, the stricter the criterion for determining that "the occupant's motion sickness has been resolved" can be.

[Software implementation example]
The control blocks of the control device 10 may be realized by a logic circuit (hardware) formed on an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the control device 10 includes a computer that executes instructions of a program, which is software that realizes each function. This computer includes, for example, at least one processor and at least one computer-readable recording medium that stores the program. The object of the present disclosure is achieved by having the processor read and execute the program from the recording medium in the computer.

The processor may be, for example, a CPU (Central Processing Unit). The recording medium may be a "non-transient tangible medium", such as a ROM (Read Only Memory), tape, disk, card, semiconductor memory, programmable logic circuit, or the like. The computer may further include a RAM (Random Access Memory) for expanding the program. The program may be supplied to the computer via any transmission medium capable of transmitting the program (such as a communication network or broadcast waves). One aspect of the present disclosure may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission. In addition, it is also possible to realize the functions of each control block by, for example, a quantum computer.

This disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure.

(1: Purpose)
The following test was conducted to investigate whether blowing air onto a person suffering from motion sickness would relieve the motion sickness.

(2: Test conditions)
Subjects suffering from motion sickness were placed in the following four conditions (a) to (d), and the time it took for each subject to recover from motion sickness was measured. There were four subjects in each of the conditions (a) to (d).

(a) Non-intervention: Leave the condition without any treatment.

(b) Interval airflow: Air is blown intermittently at the neck of each subject at a speed of 10 m/s.

(c) Continuous airflow: Air is blown continuously onto each subject's neck at a speed of 10 m/s.

(d) Continuous strong airflow: Air is blown continuously at the neck of each subject at a speed of 25 m/s.

In this test, whether or not a subject was suffering from motion sickness was judged by the subject's own sensory evaluation. In other words, a person who declared that they had motion sickness was considered a subject, and if the subject declared that they did not have motion sickness, they were judged to have recovered from motion sickness. More specifically, in this test, a person was asked to declare that they had motion sickness if they experienced symptoms such as headache, nausea, or fatigue, and to declare that they had recovered from motion sickness if the aforementioned symptoms had disappeared.

(3: Results and Discussion)
Figure 7 is a graph showing the time required for each group to overcome motion sickness, obtained from the results of this test. As shown in Figure 7, the subjects in the "non-intervention" group, in which no air was blown, took longer to overcome motion sickness than the subjects in the other three groups in which air was blown. In addition, the time required for the "interval air blowing" group, the "continuous air blowing" group, and the "continuous strong air blowing" group to overcome motion sickness was almost the same.

From the above, it was found that blowing air at a speed of 10 m/s or more at least to the neck of a person suffering from motion sickness is effective in relieving motion sickness. It was also found that as long as the wind speed is at least about 10 m/s, the effect of relieving motion sickness is almost the same whether the air is blown intermittently or continuously. It was also found that the effect of relieving motion sickness is almost the same whether the air is blown at a speed of at least 10 m/s or 25 m/s.

(1: Purpose)
The following test was carried out to investigate the change in VLF value when air was blown onto a person suffering from motion sickness.

(2: Test conditions)
The following two types of tests (e) and (f) were carried out.

(e) Three subjects were placed in a car until they began to feel motion sick, and their heart rates were measured before and after they began to feel motion sick.

(f) The same three subjects as in test (e) were placed in a car until they began to feel motion sick, as in test (e), and their heart rates were measured before and after they began to feel motion sick. However, in this test, when the subjects began to feel motion sick, air was started to be blown at the subjects' necks at a speed of 20 m/s.

In this test, as in Example 1, whether or not the subject was in a state of motion sickness was judged by the subject's own sensory evaluation. Furthermore, the heart rate signals obtained in tests (e) and (f) were analyzed, respectively, to calculate the Z scores of the subjects' VLF in tests (e) and (f). The calculated Z scores were plotted on a graph.

(3: Results and Discussion)
8 is a graph showing the transition of the Z-score of the VLF of the heart rate of the subjects obtained as a result of this test. The vertical axis of FIG. 8 shows the Z-score, and the horizontal axis shows the time. Note that the horizontal axis is set to 0 at the time when each subject reached a state of motion sickness.

It is generally said that an increase in the Z-score of the VLF of the heart rate indicates activation of the sympathetic nervous system. As shown in the graph in Figure 8, it was found that when no air was blown on a subject suffering from motion sickness, the VLF Z-score decreased. On the other hand, it was found that when air was blown on a subject suffering from motion sickness, the VLF value increased.

Therefore, the results of this study show that blowing air onto the neck of a person suffering from motion sickness can increase the VLF Z-score, i.e., activate the sympathetic nervous system of that person.

REFERENCE SIGNS LIST 1 Mobile object 10 Control device 11 Biometric information acquisition unit 12 Determination unit 13 Output control unit 14 VLF calculation unit 15 Resolution determination unit 20 Biometric sensor 21 Heart rate sensor 30 Storage device 31 VLF data 32 Output pattern information 40 Blower device 60 Past 100 Control system 151 Reference value determination unit 152 Comparison value determination unit 153 Comparison unit

Claims (8)

a biometric information acquiring unit that acquires biometric information of an occupant staying in an interior space of the moving body from a biometric sensor;
a sickness determination unit that determines whether the occupant has motion sickness based on the biological information of the occupant;
A control device comprising: a resolution determination unit that, after it is determined that the occupant has motion sickness, determines whether the occupant's motion sickness has been resolved based on the value of an ultra-low frequency component calculated based on the occupant's heart rate measured by a heart rate sensor. An output control unit that controls a stimulating device disposed in the internal space,
The output control unit is
When it is determined that the occupant has motion sickness, the stimulus application device starts applying a stimulus to the occupant;
2. The control device according to claim 1, further comprising: a control unit for controlling the stimulus application device to stop applying the stimulus to the occupant when it is determined that the motion sickness of the occupant has been relieved. The control device according to claim 2, characterized in that the stimulus application device is a blower device, and the stimulus to the occupant is a stimulus by the wind blown by the blower device. an air outlet of the air blowing device is provided in a neck portion of a seat of the moving body,
The control device according to claim 3 , wherein the output control unit adjusts at least one of a position and a direction of the air outlet so that the air blown out from the air outlet hits the neck of the occupant. a reference value determination unit that determines, as a reference value, the latest value of the ultra-low frequency component obtained by analyzing the heart rate during a period not affected by the application of the stimulus by the stimulus application device, among the values of the ultra-low frequency component;
and a comparison value determining unit that determines, as a comparison value, a value of the ultra-low frequency component obtained by analyzing a heart rate during a period during which the heart rate is affected by the application of the stimulus by the stimulus application device, among the values of the ultra-low frequency component;
5. The control device according to claim 2, wherein the resolution determination unit determines that the motion sickness of the occupant has been resolved when the comparison value is greater than the reference value. The control device according to claim 5, characterized in that the comparison value determination unit determines the largest value among the values of the ultra-low frequency components obtained by analyzing the heart rate during the period affected by the application of the stimulus as the comparison value. A control device according to any one of claims 1 to 6,
The biosensor;
and the heart rate sensor. A method for operating the control device of claim 1, comprising the steps of:
a biometric information acquiring step in which the biometric information acquiring unit acquires biometric information of the occupant staying in the internal space of the moving body from the biometric sensor;
a sickness determination step in which the sickness determination unit determines whether the occupant has motion sickness based on the biological information of the occupant acquired from the biological sensor;
A method for operating a control device, comprising: a resolution determination step in which, after it is determined that the occupant has motion sickness, the resolution determination unit determines whether the occupant's motion sickness has been resolved based on the value of the ultra-low frequency component.

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