GB2567856A

GB2567856A - Anti-motion sickness device

Info

Publication number: GB2567856A
Application number: GB1717666.0A
Authority: GB
Inventors: Salter Spencer
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2017-10-27
Filing date: 2017-10-27
Publication date: 2019-05-01
Anticipated expiration: 2037-10-27
Also published as: GB201717666D0; GB2567856B

Abstract

There is provided a method for improving comfort of an occupant of a vehicle, particularly for relieving motion sickness or carsickness. The method comprises receiving data from sensors S502 measuring the physiological properties of the occupant and data regarding one or more dynamic properties of the vehicle e.g. yaw, pitch, etc. In dependence on the received data, a probability of motion sickness of the vehicle occupant is determined S504 and this probability is compared to a threshold value S506. If the determined probability of motion sickness exceeds the threshold value S508, a vehicle orientation is determined and a datum e.g. artificial horizon, is displayed at a position within the vehicle in dependence on the determined vehicle orientation S510. The horizon may be projected onto the vehicle interior or displayed on a screen. The horizon may be displayed at an angle depending on the roll or pitch of the vehicle. The horizon may not be displayed if the occupant is asleep, and the threshold value may be dependent on the age, gender and motion sickness dose value of the occupant S505.

Description

ANTI-MOTION SICKNESS DEVICE

TECHNICAL FIELD

The present disclosure relates to a means for improving vehicle occupant comfort. Particularly, but not exclusively, the disclosure relates to reducing the probability that a vehicle occupant will experience motion sickness. Aspects of the invention relate to a method for improving comfort of an occupant of a vehicle, to a computer readable medium, to a system for improving comfort of a vehicle occupant in a vehicle, and to a vehicle.

BACKGROUND

There is a desire to improve the comfort of persons travelling in a vehicle.

There are several factors that affect the comfort of a vehicle occupant, including the environmental conditions within the vehicle. Whilst vehicle occupants may have some control over the environmental conditions (for example road vehicles often provide user controls for adjusting heating and cooling of the interior of the vehicle), the inputs provided by the occupants can sometimes be sub-optimal. For example some occupants might overcompensate for a difference in the actual temperature and the desired temperature, which can be inefficient.

Another factor that affects the comfort of a vehicle occupant is whether they are experiencing motion sickness. Motion sickness (which is also referred to as kinetosis) is a condition that can affect persons travelling in a vehicle and includes car sickness and seasickness. Motion sickness can be induced by motion of the vehicle, wherein the vehicle occupant's vestibular system senses the motion, but the vehicle occupant's visual system provides an output that is in conflict with the sensed motion. For example, a passenger in a road vehicle looking at a location within the vehicle (for example reading a book) may perceive very little motion visually, because the location (e.g. the book) is only moving a small amount relative to the user. However the vehicle itself may be moving a greater amount, thus the passenger's vestibular system senses a greater movement. As a result, the passenger may begin to feel the symptoms of motion sickness. The symptoms of motion sickness include nausea, dizziness and fatigue, and if the symptoms are not alleviated in time, motion sickness can result in vomiting.

The onset of motion sickness depends on several factors, including the direction and frequency of the motion - in the case of a road vehicle, this motion may be determined by the surface roughness of the road, the radius of a corner being traversed, etc. The unique physiological response of the vehicle occupant also affects the onset of motion sickness, with certain people being more susceptible to motion sickness than others. The age and gender of the vehicle occupant can also have an effect on the onset of motion sickness.

Whilst the physiological effect of motion sickness may differ between persons, motion sickness can be quantified by a motion sickness dose value (MSDV), which is defined in standard ISO 2631 and BS6841 1987. A motion sickness dose value is calculated based on a frequency weighted acceleration of a person in a vertical direction and the amount of time the person is experiencing the motion, and gives an indication of the probability, or likelihood, that the person is experiencing motion sickness.

In order to alleviate the symptoms of motion sickness, it is known to stop the motion of the vehicle where possible. For example, otherwise unnecessary stops can be made during a journey in a road vehicle to attempt to alleviate the symptoms of motion sickness. However such action is inconvenient, and is not always possible (for example during a journey by sea or air, or a road journey on roads where stopping is not permitted or otherwise not possible). Moreover, simply stopping the motion of the vehicle when a person begins to feel the effects of motion sickness may have only limited effectiveness, since the vehicle occupant may only begin feeling the symptoms of motion sickness at a time after the onset of the motion sickness - the earlier that remedial action is taken after the onset of motion sickness, the more effective the remedial action is.

With the advent of autonomous vehicles, the propensity for motion sickness to occur is predicted to increase. Motion sickness in vehicles is known to affect passengers to a greater extent than persons controlling the vehicle. Moreover the usage of road vehicles has the potential to change as autonomy becomes more prevalent, with vehicle occupants predicted to spend more time engaging with vehicle entertainment systems, performing work related tasks, using personal computing devices, reading etc., increasing the chance for discrepancies between visual input and vestibular response to arise.

Accordingly there is a desire to improve the comfort of vehicle occupants, in particular by reducing the probability that the vehicle occupant experiences the symptoms of motion sickness.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a method, controller and system for improving comfort of an occupant of a vehicle, and a vehicle, as claimed in the appended claims.

There is provided a method for improving comfort of an occupant of a vehicle, the method comprising: receiving, from one or more sensors, data indicative of one or more of: one or more measured physiological properties of the vehicle occupant; and one or more dynamic properties of the vehicle; determining, in dependence on the received data, a probability of motion sickness of the vehicle occupant; comparing the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value: determining a vehicle orientation; displaying a datum at a position within the vehicle in dependence on the determined vehicle orientation.

Advantageously the method therefore monitors the physiological properties of the occupant and the dynamic, motion based properties of the vehicle and determines from these properties the likelihood that the occupant will experience motion sickness. In the event that it is determined that the occupant is likely to experience motion sickness remedial action is taken, in the form of a display of a datum, such as an artificial horizon within the cabin of the vehicle. By displaying a reference point it is found that the feeling of motion sickness can be reduced as the occupant is provided with a reference point which reduces the disparity between the visual and vestibular systems.

In further embodiments the datum represents an artificial horizon corresponding to a substantially horizontal plane (with respect to the gravitational plane) or wherein the datum corresponds to a plane having a non-zero first angle with respect to a horizontal plane. Typically displaying the datum at a horizontal plane will provide sufficient relief to the occupant however it is also found that by displaying the datum at a non-zero angle compared to the horizontal may provide a greater relief to the occupant.

In a further embodiment the method further comprises receiving, from the one or more sensors, data indicative of the one or more dynamic properties of the vehicle; determining, in dependence on the data indicative of the one or more dynamic properties of the vehicle, that the vehicle is experiencing one or more of roll and pitch; determining, in dependence on the data indicative of the one or more dynamic properties of the vehicle, one or more of: an angle of roll of the vehicle about a first axis with respect to the horizontal plane; and an angle of pitch of the vehicle about a second axis with respect to the horizontal plane; determining the first angle in dependence on one or more of: the angle of roll of the vehicle; and the angle of pitch of the vehicle. Optionally wherein: the determined first angle decreases with respect to the first axis as the angle of roll about the first axis increases; or the determined first angle decreases with respect to the second axis as the angle of pitch about the second axis increases. Thus enabling an accurate determination of the placement of the datum within the vehicle cabin which compensates for the motion of the vehicle.

In a further embodiment the method comprises receiving camera data from a camera viewing the vehicle occupant; analysing the camera data to determine a field of view of the vehicle occupant; and adjusting the position at which the datum is displayed within the vehicle such that the datum is visible to the vehicle occupant. This beneficially ensures that the datum is visible to the occupant to provide the relief, and increase the occupant comfort.

In a further embodiment the data is indicative of one or more measured physiological properties of the vehicle occupant, and wherein receiving data comprises receiving one or more of: heart rate data; heart rate variability data; heat flow data representative of a heat flow at the vehicle occupant's skin; and temperature data; and image data. Such data enables a more accurate determination of the likelihood of motion sickness to be made. Optionally the method further comprises determining, in dependence on the data, whether the vehicle occupant is asleep; and if the vehicle occupant is asleep, forgoing display of the datum which saves energy as no action is taken if the occupant cannot view the datum.

In a further embodiment the received data comprises image data, and the method further comprises: analysing the image data to determine at least one of an age and gender of the vehicle occupant; and adjusting or selecting a value for the threshold value in dependence on the determined at least one of age and gender of the vehicle occupant. As the likelihood of experiencing motion sickness is dependent on such factors the method compensates accordingly.

In a further embodiment the data is indicative of one or more measured dynamic properties of the vehicle, the method comprising: determining, in dependence on the data, a motion sickness dose value of the vehicle occupant; and determining the probability of motion sickness of the vehicle occupant in dependence on the determined motion sickness dose value of the vehicle occupant. Motion sickness dose value is a known, defined, measure of the amount of motion sickness that a person will experience and therefore can also be used to determine the likelihood that they will experience motion sickness.

According to a further aspect of the invention, there is provided a controller for improving comfort of a vehicle occupant in a vehicle, the controller configured to: receive from one or more sensors, data indicative of one or more of: one or more measured physiological properties of the vehicle occupant; and one or more dynamic properties of the vehicle; determine, in dependence on the received data, a probability of motion sickness of the vehicle occupant; compare the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value: determine a vehicle orientation; cause a display unit to display a datum at a position within the vehicle in dependence on the determined vehicle orientation.

According to a still further aspect of the invention, there is provided a system comprising a controller for improving comfort of a vehicle occupant in a vehicle, the controller configured to: receive from one or more sensors, data indicative of one or more of: one or more measured physiological properties of the vehicle occupant; and one or more dynamic properties of the vehicle; determine, in dependence on the received data, a probability of motion sickness of the vehicle occupant; compare the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value: determine a vehicle orientation; cause a display unit to display a datum at a position within the vehicle in dependence on the determined vehicle orientation; wherein the system further comprises the one or more sensors and the display unit.

According to another aspect of the invention, there is provided a vehicle comprising for improving comfort of a vehicle occupant in a vehicle, the controller configured to: receive from one or more sensors, data indicative of one or more of: one or more measured physiological properties of the vehicle occupant; and one or more dynamic properties of the vehicle; determine, in dependence on the received data, a probability of motion sickness of the vehicle occupant; compare the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value: determine a vehicle orientation; cause a display unit to display a datum at a position within the vehicle in dependence on the determined vehicle orientation, wherein the vehicle optionally further comprises the one or more sensors and the display unit.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic of a system for improving comfort of a vehicle occupant in a vehicle in accordance with an embodiment of the invention;

Figure 2 is a schematic of a vehicle In accordance with an aspect of the invention;

Figure 3 is a schematic of a wearable device in accordance with some embodiments of the present invention;

Figure 4A shows a representation of an artificial horizon projected onto the interior of a vehicle;

Figure 4B shows an arrangement for projecting an artificial horizon; and

Figure 5 is a flow diagram of a method for improving comfort of an occupant of a vehicle in accordance with the claimed invention.

DETAILED DESCRIPTION

Figure 1 is a schematic of a system 100 for improving comfort of a vehicle occupant in a vehicle. Figure 2 shows a vehicle 200 comprising the system 100. As shown in figure 2, the vehicle 200 is a car, however it will be appreciated that the present invention may be applied to a wide range of vehicles, including road vehicles, aircraft, boats, etc.

The system 100 comprises a set of sensors 102. The set of sensors 102 includes at least one of: one or more occupant sensors 104, 106 configured to measure physiological properties of occupant in a vehicle; and one or more vehicle motion sensors 108, 110 configured to measure dynamic motion properties of the vehicle 200. The vehicle motion sensors 108, 110 are any appropriate sensors for measuring the dynamic motion properties of the vehicle 200, for example inertial or other motion-related properties, such as velocity, acceleration, pitch angle and/or rate, yaw angle and/or rate, roll angle and/or rate etc. In a preferred embodiment, the set of sensors 102 comprises both occupant sensors 104, 106 and vehicle motion sensors 108, 110. The system 100 also comprises a processor 112 in communication with the set of sensors 102. The processor 112 may be connected to the set of sensors 102 by wired or wireless means as is known in the art. In some examples some of the sensors 104, 106, 108, 110 are connected to the processor wirelessly, whilst other sensors 104, 106, 108, 110 are connected by wired means. This is advantageous when some of the sensors 104, 106, 108, 110 are integral to a vehicle whereas other sensors 104, 106, 108, 110 are integrated in an electronic device associated with a vehicle occupant (see below). Optionally the system 100 comprises a communications unit 113, configured to allow wireless communication between the processor 112 and one or more of the sensors 104, 106, 108, 110. The system further comprises a form of writeable memory 116.

The vehicle motion sensors 108, 110 measure dynamic properties of the vehicle, such as inertial properties, of the vehicle 200 in which the system is implemented. For example, the vehicle motion sensors 108, 110 measure dynamic properties such as one or more of a roll angle and/or rate, pitch angle and/or rate, yaw angle and/or rate, acceleration, deceleration, wheel orientation etc. of a vehicle. In one example, the vehicle motion sensors 108, 110 are 7 an inertial measurement unit (IMU) integrated in the vehicle 200 as is known in the art and are commercially available. Advantageously, data collected by the vehicle motion sensors 108, 110 can be used to determine the dynamic motions that the vehicle occupant has been cumulatively subjected to whilst travelling in the vehicle. From this it is possible to calculate a motion sickness dose value (MSDV) for the occupant using the formula defined in ISO 2631 (or by another suitable method), or other measures of the probability, or likelihood, that the occupant is likely to be experiencing motion sickness. In one example, data from an IMU is used to determine the motion experienced at by an occupant at a particular location within the vehicle. For example an occupant situated near a wheel will experience different motion compared to another occupant situated near the centre of the vehicle, as such the MSDV, or the likelihood of motion sickness, experienced by an occupant will vary according to their location within the vehicle.

The occupant sensors 104, 106 measure one or more physiological properties of one or more occupants in the vehicle 200, for example the occupant's heart rate, heart rate variability, vasodilation, and skin temperature, skin heat flow. Preferably the occupant sensors 104,106 comprise at least one of:

• A heart rate sensor configured to measure the heart rate and heart rate variability of the occupant. Increased heart rate, and in particular increased heart rate variability has been found to be an indicator that an occupant is experiencing motion sickness. Thus beneficially this data can be used in a calculation to determine the probability that the occupant is experiencing motion sickness. The heart rate sensor may be any such sensor known in the art.

• A temperature sensor (such as an infrared sensor, thermal camera, thermo electric device etc.) configured to measure the temperature of the occupant's skin. It has been found that increased vasodilation is an indication that motion sickness is being experienced by a person. Vasodilation can cause an increase in skin temperature, thus skin temperature can be used in a calculation to determine the probability that the occupant is experiencing motion sickness.

• A humidity sensor configured to measure the humidity at the occupant's skin. It has been found that increased perspiration is an indication that motion sickness is being experienced by a person. By measuring humidity at the occupant's skin, the occupant's perspiration can be inferred, and used to calculate a probability that the occupant is experiencing motion sickness.

• A heat flow sensor (such as a Peltier device, see below) configured to measure the flow of heat through the occupant's skin. Measuring the flow of heat through the occupant's skin has been found to provide a more accurate indication of vasodilation than just measuring temperature and humidity, since it automatically accounts for changes in temperature that are due to environmental conditions rather than motion sickness. Thus heat flow at the occupant's skin can be used in a calculation to determine the probability that the occupant is experiencing motion sickness.

• An optical camera configured to record images of the occupant. Motion sickness has been found to cause changes in skin colour, for example due to vasodilation, or due to decreased blood flow to the skin preceding vomiting. Accordingly images of the occupant can be analysed to detect changes in skin colour, which can be used in a calculation to determine the probability that the occupant is experiencing motion sickness. The images may also be used to estimate or determine the age and/or gender of the occupant - it has been found that age and gender affects how likely a person is to experience motion sickness for a given set of conditions. The image data can also be used to determine the amount of time an occupant spends looking up or down. It is known that when an occupant looks downwards the probability of them experiencing motion sickness increases.

The set of sensors 102 optionally comprises sensors configured to take environmental measurements, for example:

• A temperature sensor (such as an infrared sensor, thermal camera, thermocouple or other thermoelectric device etc.) configured to measure the ambient temperature in the vehicle 200. It has been found that ambient temperature can affect the probability that a person will experience motion sickness for a given set of motion conditions.

• A temperature sensor (such as an infrared sensor, thermal camera, thermocouple or other thermoelectric device etc.) ambient temperature outside the vehicle 200.

• A humidity sensor configured to measure the ambient humidity in the vehicle 200. It has been found that ambient humidity can affect the probability that a person will experience motion sickness for a given set of motion conditions.

• A sun load sensor (for example a photovoltaic sensor or camera) configured to detect a part of the interior of the vehicle being subjected to a high thermal load due to solar radiation, and thus locally heating that part of the interior of the vehicle.

In one embodiment, one or more of the sensors 104, 106, 108, 110 are associated with a portable electronic device. For example the occupant sensors 104, 106 are included in a portable electronic device or are attached to a portable electronic device, such as a smartphone or tablet. In another example, the occupant sensors 104, 106 are included in a wearable device being worn by the occupant.

Figure 3 shows a schematic of a wearable device 300. The wearable device 300 may be a smart watch, activity tracker, fitness tracker or other portable electronic device that can be worn by a vehicle occupant.

The wearable device 300 comprises one or more occupant sensors 302 such as the occupant sensors 104, 106 described above in relation to figure 1. In one example the wearable device further comprises a motion sensor 304 (for example an accelerometer) configured to measure a dynamic motion property of the wearer of the wearable device. In one example, the measured motion of the wearable device is advantageously used to estimate the motion of the occupant due to motion of the vehicle 200.

The wearable device 300 comprises a processor 306 configured to control the wearable device 300. In some embodiments, the wearable device processor 306 may be the same as the processor 112 described above in relation to figure 1. Alternatively the processor 112 of figure 1 is integrated into vehicle 200 and is separate from the wearable device processor 306.

The wearable deice 300 also comprises a communications module 308 configured to transmit and receive data. The communications module may be a wireless communications (e.g. Wi-Fi, Bluetooth, etc.) module as known in the art.

In another embodiment, the wearable device 300 is configured to communicate with a further portable electronic device, the further portable device comprising a processor.

Returning to figure 1, each sensor 104, 106, 108, 110 is configured to send data to the processor 112. The processor 112 is configured to calculate a probability, or likelihood, that a given vehicle occupant is experiencing motion sickness based on data received from the set of sensors. Preferably, the processor is configured to calculate the probability of motion sickness for each occupant in the vehicle in turn. For ease of understanding, the disclosure 10 describes the calculation of the probability of motion sickness for a single occupant, however the principles described herein may be repeated for multiple occupants within a vehicle. In the case that the system comprises the wearable device 300 of figure 3, the processor 112 may either be the wearable device's own processor 306 or a separate processor (for example a processor integrated into the vehicle, wherein the data is transmitted from the wearable device communications module 308 to the vehicle integrated processor via optional communications unit 113). Optionally, the processor 112 is further configured to determine whether an occupant is asleep based on data from the sensors 104, 106, 108, 110 for example by analysing image data from a camera to determine that the occupant has their eyes shut, or by determining that the occupant's heart rate, heart rate variability and/or vasodilation corresponds to the occupant being asleep. Optionally the processor is further configured to determine an age and/or gender of the occupant, for example based on an analysis of image data from a camera, or by retrieving stored data describing the age and/or gender of the occupant. In an embodiment the data is stored on a form of writeable memory associated with the wearable device 300, alternatively, or additionally, the data is stored on the system memory 116.

In one embodiment, the processor 112 is configured to receive historical occupant sensor data describing historical physiological parameters of the occupant. For example, the processor may receive a baseline describing physiological parameters considered to be normal for the occupant. In this embodiment, the processor 112 is configured to calculate a probability of motion sickness value for the occupant by comparing current data from the sensors to the historical data, to determine if the current physiological parameters of the occupant differ from the historical physiological parameters in a manner indicative of the occupant experiencing motion sickness. For example the processor may determine from current data from the occupant sensors 104, 106 that the physiological parameters of the occupant deviate from the baseline in a way that is indicative of motion sickness.

The system 100 further comprises a display unit 114. The display unit is configured to display a datum within the vehicle 200. The datum in an example is in the form of a line projected within the interior of the cabin of the vehicle 200, where the line projected is indicative of a horizon. The datum representative of a horizon describes a feature displayed within the vehicle 200 at positions corresponding to the intersection of a plane and the vehicle interior. The plane either corresponds to an actual horizon (i.e. the plane is substantially parallel to the horizontal), or can lie at an angle relative to the actual horizon as explained below. In some examples the datum is a line displayed on the interior of the vehicle. Alternatively, the datum comprises one or more graphical images, such as an image displaying a tonal variation in a direction parallel to the plane, an image of an exterior scene, etc. The datum need not be continuous around the entire interior of the vehicle, i.e. the line/graphical images may displayed only at certain locations within the interior of the vehicle.

The display unit 114 may be any suitable device or group of devices for displaying a datum, such as an artificial horizon, including: one or more projectors configured to project the datum on the interior of the vehicle, one or more display screens (for example LCD displays) positioned at one or more locations in the interior of the vehicle configured to display the datum, one or more light emitting devices positioned at one or more locations in the interior of the vehicle configured to display the datum.

The processor 112 is configured to cause the display unit 114 to display the datum, such as an artificial horizon, at the correct position on the interior of the vehicle 200. In an embodiment the processor 112 uses data from the vehicle motion sensors 108, 110 to determine the orientation of the vehicle relative to a reference orientation (for example a horizontal plane). The processor 112 then calculates, based on the determined orientation of the vehicle, one or more positions on the interior of the vehicle 200 at which the plane corresponding to an artificial horizon intersect the vehicle interior (for example a substantially horizontal plane), and causes the display unit 114 to display the datum at the calculated positions on the interior of the vehicle 200.

In some embodiments, the datum is only displayed at locations on the interior of the vehicle 200 that correspond to the periphery of the occupant's field of view, i.e. the datum is only displayed in locations corresponding to the occupant's peripheral vision. Advantageously, this has been found to provide enough visible stimulation to the occupant so as to reduce the effects of motion sickness. This has the further benefit that the extent of the datum (such as a horizon) displayed at any one time is limited, helping to reduce the power consumption that would otherwise be associated with displaying the datum throughout the whole of the interior of the vehicle 200 (reducing power consumption is a particularly important consideration for electric vehicles, where reducing power consumption to increase range is a primary concern). Moreover, the display of the datum may be less appealing to other passengers in the vehicle, and thus limiting the amount of space the datum occupies when being displayed can improve the comfort/experience of other passengers.

Advantageously, by displaying the datum, the vehicle occupant receives a visual stimulus that corresponds to the motion experienced by their vestibular system, thus reducing the effects of motion sickness. This is particularly advantageous in situations in which the actual horizon is not visible to the vehicle occupant, who therefore would ordinarily receive little or no visual stimulus corresponding to the motion experienced by their vestibular system, for example: when the occupant is not positioned near a window; when travelling a night or in poor weather, when the occupant is reading, using an electronic device, or otherwise looking at a location within the vehicle such that little or no actual horizon can be seen.

In one embodiment, the datum is displayed such that it corresponds to a plane lying at an angle relative to the actual horizon, i.e. it is not parallel to the horizon. In particular, the processor 112 determines, based on data from the vehicle motion sensors 108, 110 whether the vehicle 200 is currently experiencing one or more of roll and pitch. If so, the processor 112 determines one or more of: an angle of roll of the vehicle 200 about a first axis (for example a roll axis or roll centre); and an angle of pitch of the vehicle 200 about a second axis (for example a pitch axis). The angle of the plane corresponding to the datum relative to the actual horizon is then chosen based on the angle of roll and/or the angle of pitch. Preferably the angle of the plane is chosen such that it decrease with respect to the first axis as the angle of roll about the first axis increases; and/or decreases with respect to the second axis as the angle of pitch about the second axis increases. This has the effect that the displayed datum appears to exaggerate the motion of the vehicle, for example when cornering. Advantageously, this has the effect of further reducing discrepancies between the occupant's vestibular and visual systems, thus further reducing the effects of motion sickness/making the onset of motion sickness less likely.

In embodiments in which set of sensors 102 includes an optical camera, the processor 112 optionally analyses data from the camera to determine a field of view of the vehicle occupant, and cause the display unit 114 to adjust a position at which the data is displayed within the vehicle, such that the datum is visible to the vehicle occupant. Advantageously this ensures that the datum, such as the horizon, is visible to the occupant.

Figures 4A and 4B show one example of the display unit as described with reference to Figure 1, suitable for use with the present invention. In this example a projector 402 projects the datum 404 (in this case corresponding to an image of a line) on the interior 400 of a vehicle. The projector 402 comprises a gimbal device 406 onto which a light emitting device 408 (such as a laser) is connected. The gimbal device 406 is configured to cause the light emitting device 408 to pivot, such that light 410 is projected onto the interior 400 of the vehicle such that the projected datum 404 is substantially parallel with a plane corresponding to the horizon.

Figure 5 shows a method 500 for improving comfort of an occupant of a vehicle 200, preferably performed by the processor 112.

The process described with reference to Figure 5 describes the process of monitoring the dynamic properties of the vehicle, as well as the physiological properties of one or more vehicle occupants, and based on both of the measured properties providing a response, in form a displayed datum, to alleviate and help mitigate the feeling of motion sickness experienced by one or more vehicle occupants thereby improving passenger comfort.

The method begins at step S502, in which data is received from the occupant sensors 104, 106 and/or the vehicle motion sensors 108, 110.

Using the data received in step S502, the processor 112 determines a probability of motion sickness value at step S504. This value is preferably based on the physiological properties of the occupant (from which it can be determined whether they are exhibiting signs of motion sickness, as discussed above) and the motion that the vehicle occupant is subjected to (for example by calculating an MSDV for the occupant). The likelihood or probability of motion sickness value can be determined based on the physiological properties and motion in any appropriate manner. In an embodiment the probability of motion sickness is determined as a weighted sum of the determined motion (or acceleration) experienced by the occupant, for example as calculated as the MSDV, and the physiological (e.g. occupant heart rate, temperature, etc.) and environmental data (e.g. cabin temperature, humidity etc.). In further embodiments this weighted by the percentage time the occupant has spent looking down. In further embodiments any other suitable form of calculation may be used.

In step S506, the probability of motion sickness value is compared to a predetermined threshold value. If the threshold is not exceeded, no action is taken in step S508 and the method returns to step S502. If the threshold is exceeded, it is determined in step S508 that the occupant has a high enough probability of experiencing the symptoms of motion sickness that remedial action should be taken, in which case the method proceeds to step S510.

In step S510, the processor by determines the orientation of the vehicle relative to a reference and causes a feature representing the datum to be displayed (preferably via instructions sent to the display unit 114) as discussed above. In some embodiments the datum remains displayed for a predetermined length of time before display is ended (for example the processor sends a suitable signal and/or instruction to the display unit 114 causing it to display the datum for the predetermined period of time and then cease display) and the method returns to step S502. In an alternative embodiment, during step S510, steps S502 to S506 are repeated, until the probability of motion sickness value no longer exceeds the threshold, at which point display of the datum is ended (for example by the processor 112 sending a suitable signal and/or instruction to the display unit 114) and the method returns to step S502.

Advantageously, by only displaying the datum when the threshold is exceeded, the datum is only displayed when actively needed to reduce the effects of motion sickness. Consequently the amount of time the datum is displayed can be reduced. This has been shown to be effective in reducing the effects of motion sickness in vehicle occupants. In addition, power consumption due to the display of the datum can be reduced, in that the display unit 114 (for example a projector or a series of display screens) consumes less energy. This is a particularly important consideration for electric vehicles, where reducing power consumption to increase range is a primary concern. Moreover, the display of the datum, such as in the form of an artificial horizon, may be less appealing to other passengers in the vehicle, and thus limiting the amount of time it is displayed can improve the comfort/experience of other passengers.

The threshold is preferably based on either: a predetermined set of reference physiological properties, representative of an onset of motion sickness; a predetermined reference MSDV; or both.

Optionally the threshold is dynamic. In one example, the threshold is different depending on whether the vehicle occupant is asleep. It has been found that when a person is asleep, their susceptibility to motion sickness reduces, delaying the onset of motion sickness. Accordingly a higher threshold may be set when it is determined that the occupant is asleep. Alternatively or in addition, the threshold is different depending on the determined age and gender of the occupant. As noted above, susceptibility to motion sickness has been found to have links to age and gender. Accordingly, prior to comparing the probability, or likelihood, of motion sickness value to the threshold in step S506, optionally step S505 is performed in which at least one of the occupant age, the occupant gender, and whether the occupant is asleep is determined (and/or, in the case of age, approximated), and the threshold value is chosen or adjusted as appropriate based on the determination. Alternatively, or additionally, data from the sensors, such as camera 106 106 is configured to determine the position and orientation of the occupant's head in an embodiment. A factor known to alleviate the feeling of motion sickness experienced by an individual is being able to view the horizon. By viewing the horizon the occupant is provided with a visual reference point which can help resolve any conflict between the motion sensed by the vestibular system and the viewed motion. Accordingly, when an occupant is looking downwards (for example when reading or utilising a mobile phone or tablet computer device) the amount of horizon that they are able to view is reduced. As such the likelihood of motion sickness for a given occupant will vary according to their head position, with the likelihood of motion sickness increasing depending on the orientation of their head, which affects the amount of horizon the occupant can view.

It is noted that whilst the steps of the method 500 are shown in a particular order in figure 5, the steps need not necessarily be performed in this order. In particular, optional step S505 can be performed at any point before step S506.

The method 500 may be embodied as computer readable instructions. In one embodiment, a computer readable comprises instructions that, when executed by a processor (such as the processor 112 of figure 1 or the processor 306 of figure 3), cause the processor to perform the method above. In one example, the computer readable medium is a non-transitory computer readable medium.

Further aspects and preferred features of the invention will be apparent from the appended claims.

Claims

1. A method for improving comfort of an occupant of a vehicle, the method comprising:

receiving, from one or more sensors, data indicative of one or more of:

one or more measured physiological properties of the vehicle occupant; and one or more dynamic properties of the vehicle;

determining, in dependence on the received data, a probability of motion sickness of the vehicle occupant;

comparing the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value: determining a vehicle orientation;

displaying a datum at a position within the vehicle in dependence on the determined vehicle orientation.

2. The method of claim 1, wherein the datum represents an artificial horizon corresponding to a substantially horizontal plane.

3. The method of claim 1, wherein the datum corresponds to a plane having a non-zero first angle with respect to a horizontal plane.

4. The method of claim 3 comprising:

receiving, from the one or more sensors, data indicative of the one or more dynamic properties of the vehicle;

determining, in dependence on the data indicative of the one or more dynamic properties of the vehicle, that the vehicle is experiencing one or more of roll and pitch;

determining, in dependence on the data indicative of the one or more dynamic properties of the vehicle, one or more of: an angle of roll of the vehicle about a first axis with respect to the horizontal plane; and an angle of pitch of the vehicle about a second axis with respect to the horizontal plane;

determining the first angle in dependence on one or more of: the angle of roll of the vehicle; and the angle of pitch of the vehicle.

5. The method of claim 4 wherein:

the determined first angle decreases with respect to the first axis as the angle of roll about the first axis increases; or the determined first angle decreases with respect to the second axis as the angle of pitch about the second axis increases.

6. The method of any preceding claim, comprising:

receiving camera data from a camera viewing the vehicle occupant;

analysing the camera data to determine a field of view of the vehicle occupant; and adjusting the position at which the datum is displayed within the vehicle such that the datum is visible to the vehicle occupant.

7. The method of any preceding claim, wherein the data is indicative of one or more measured physiological properties of the vehicle occupant, and wherein receiving data comprises receiving one or more of:

heart rate data;

heart rate variability data;

heat flow data representative of a heat flow at the vehicle occupant's skin; and temperature data; and image data.

8. The method of claim 7, comprising determining, in dependence on the data, whether the vehicle occupant is asleep; and if the vehicle occupant is asleep, forgoing display of the datum.

9. The method of any preceding claim, wherein receiving data comprises receiving image data, the method comprising:

analysing the image data to determine at least one of an age and gender of the vehicle occupant; and adjusting or selecting a value for the threshold value in dependence on the determined at least one of age and gender of the vehicle occupant.

10. The method of any preceding claim, wherein the data is indicative of one or more measured dynamic properties of the vehicle, the method comprising:

determining, in dependence on the data, a motion sickness dose value of the vehicle occupant;

determining the probability of motion sickness of the vehicle occupant in dependence on the determined motion sickness dose value of the vehicle occupant.

11. The method of claim 10, comprising determining the threshold value in dependence on a predetermined threshold motion sickness dose value.

12. A computer readable medium comprising instructions that, when executed by a processor, cause the processor to perform the method of any of claims 1 to 11.

13. A controller for improving comfort of a vehicle occupant in a vehicle, the controller configured to:

receive from one or more sensors, data indicative of one or more of:

determine, in dependence on the received data, a probability of motion sickness of the vehicle occupant;

compare the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value: determine a vehicle orientation;

cause a display unit to display a datum at a position within the vehicle in dependence on the determined vehicle orientation.

14. The controller of claim 13, wherein the datum corresponds to a substantially horizontal plane.

15. The controller of claim 13, wherein the datum corresponds to a plane having a non-zero first angle with respect to a horizontal plane.

16. The controller of claim 15, configured to:

receive data indicative of the one or more dynamic properties of the vehicle; and determine, in dependence on the measured one or more dynamic properties of the vehicle, that the vehicle is experiencing one or more of roll and pitch;

determine, in dependence on the measured one or more dynamic properties of the vehicle, one or more of: an angle of roll of the vehicle about a first axis; and an angle of pitch of the vehicle about a second axis;

determine the first angle in dependence on one or more of: the angle of roll of the vehicle; and the angle of pitch of the vehicle.

17. The controller of claim 16, wherein:

18. The controller of any of claims 13 to 17, configured to:

receive camera data from a camera configured to view the vehicle occupant; analyse the camera data to determine a field of view of the vehicle occupant;

cause the display unit to adjust a position at which the datum is displayed within the vehicle, such that the datum is visible to the vehicle occupant.

19. The controller of any of claims 13 to 18, configured to receive data indicative of the one or more measured physiological properties of the vehicle occupant, wherein the data is indicative at least one of:

heart rate;

heart rate variability;

heat flow at the vehicle occupant's skin; and temperature.

20. The controller of any of claims 13 to 19, configured to receive image data indicative of a captured image of the vehicle occupant.

21. The controller of claim 20, configured to determine, in dependence on the image data, whether the vehicle occupant is asleep; and if the vehicle occupant is asleep, forgo causing the display unit to display the datum.

22. The controller of claim 20, configured to:

analyse the image data to determine at least one of an age and gender of the vehicle occupant; and adjust or select a value for the threshold value in dependence on the determined at least one of age and gender of the vehicle occupant.

23. The controller of any of claims 13 to 22, configured to:

receive data indicative of the one or more dynamic properties of the vehicle; and determine, in dependence on the data, a motion sickness dose value of the vehicle occupant;

determine the probability of motion sickness of the vehicle occupant in dependence on the determined motion sickness dose value of the vehicle occupant.

24. The controller of claim 23, configured to determine the threshold value in dependence on a predetermined threshold motion sickness dose value.

25. The controller of any of claims 13 to 24 wherein the dynamic properties of the vehicle comprise one or more of:

a yaw of the vehicle;

a pitch of the vehicle;

a roll of the vehicle;

a velocity of the vehicle; and an acceleration of the vehicle.

26. A system comprising:

the controller of any of claims 13 to 25;

the one or more sensors; and the display unit.

27. The system of claim 26 comprising a camera configured to capture an image of the vehicle occupant

28. The system of any of claims 25 to 27 comprising a second portable device in communication with the first portable electronic device, wherein the second portable electronic device comprises the controller.

29 A vehicle comprising the controller of any of claims 11 to 21, or the system of any of claims 22 to 28.

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28. The system of any of claims 26 to 27, wherein the display unit comprises at least one of:

a projector configured to project the datum on one or more interior surfaces of the vehicle; and one or more display screens disposed inside the vehicle.

29. The system of any of claims 26 to 28, comprising a first portable electronic device, wherein the portable electronic device comprises at least one of the one or more sensors.

30. The system of claim 29, wherein the first portable device is a wearable device.

31. The system of claim 29 or claim 30, wherein the first portable device comprises the controller.

32. The system of any of claims 29 to 31 comprising a second portable device in

5 communication with the first portable electronic device, wherein the second portable electronic device comprises the controller.

33 A vehicle comprising the controller of any of claims 13 to 25, or the system of any of claims 26 to 32.

Amendments to the claims have been filed as follows:

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receiving, from one or more sensors, data indicative of one or more of:

5 one or more measured physiological properties of the vehicle occupant; and one or more dynamic properties of the vehicle;

comparing the determined probability of motion sickness to a threshold value; and

10 if the determined probability of motion sickness exceeds the threshold value:

determining a vehicle orientation;

displaying a datum at a position within the vehicle in dependence on the determined vehicle orientation, wherein the datum corresponds to a plane having a non-zero first angle with respect to a horizontal plane;

15 receiving, from the one or more sensors, data indicative of the one or more dynamic properties of the vehicle;

determining, in dependence on the data indicative of the one or more dynamic 20 properties of the vehicle, one or more of: an angle of roll of the vehicle about a first axis with respect to the horizontal plane; and an angle of pitch of the vehicle about a second axis with respect to the horizontal plane; and determining the first angle in dependence on one or more of: the angle of roll of the vehicle; and the angle of pitch of the vehicle.

3. The method of claim 2 wherein:

30 the determined first angle decreases with respect to the first axis as the angle of roll about the first axis increases; or the determined first angle decreases with respect to the second axis as the angle of pitch about the second axis increases.

35 4. The method of any preceding claim, comprising:

05 11 18 receiving camera data from a camera viewing the vehicle occupant;

5. The method of any preceding claim, wherein the data is indicative of one or more measured physiological properties of the vehicle occupant, and wherein receiving data comprises receiving one or more of:

heart rate data;

10 heart rate variability data;

15 6. The method of claim 5, comprising determining, in dependence on the data, whether the vehicle occupant is asleep; and if the vehicle occupant is asleep, forgoing display of the datum.

7. The method of any preceding claim, wherein receiving data comprises receiving image 20 data, the method comprising:

8. The method of any preceding claim, wherein the data is indicative of one or more measured dynamic properties of the vehicle, the method comprising:

30 determining the probability of motion sickness of the vehicle occupant in dependence on the determined motion sickness dose value of the vehicle occupant.

9. The method of claim 8, comprising determining the threshold value in dependence on a predetermined threshold motion sickness dose value.

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10. A computer readable medium comprising instructions that, when executed by a processor, cause the processor to perform the method of any of claims 1 to 9.

11. A controller for improving comfort of a vehicle occupant in a vehicle, the controller 5 configured to:

receive from one or more sensors, data indicative of one or more of:

determine, in dependence on the received data, a probability of motion sickness of 10 the vehicle occupant;

compare the determined probability of motion sickness to a threshold value; and if the determined probability of motion sickness exceeds the threshold value:

determine a vehicle orientation;

cause a display unit to display a datum at a position within the vehicle in dependence

15 on the determined vehicle orientation, the datum corresponding to a plane having a non-zero first angle with respect to a horizontal plane;

receive data indicative of the one or more dynamic properties of the vehicle;

determine, in dependence on the measured one or more dynamic properties of the vehicle, that the vehicle is experiencing one or more of roll and pitch;

20 determine, in dependence on the measured one or more dynamic properties of the vehicle, one or more of: an angle of roll of the vehicle about a first axis; and an angle of pitch of the vehicle about a second axis; and determine the first angle in dependence on one or more of: the angle of roll of the vehicle; and the angle of pitch of the vehicle.

12. The controller of claim 11, wherein the datum corresponds to a substantially horizontal plane.

13. The controller of claim 12, wherein:

35 14. The controller of any of claims 11 to 13, configured to:

05 11 18 receive camera data from a camera configured to view the vehicle occupant; analyse the camera data to determine a field of view of the vehicle occupant; cause the display unit to adjust a position at which the datum is displayed within the vehicle, such that the datum is visible to the vehicle occupant.

15. The controller of any of claims 11 to 14, configured to receive data indicative of the one or more measured physiological properties of the vehicle occupant, wherein the data is indicative at least one of:

heart rate;

10 heart rate variability;

heat flow at the vehicle occupant's skin; and temperature.

16. The controller of any of claims 11 to 15, configured to receive image data indicative of a 15 captured image of the vehicle occupant.

17. The controller of claim 16, configured to determine, in dependence on the image data, whether the vehicle occupant is asleep; and if the vehicle occupant is asleep, forgo causing the display unit to display the datum.

18. The controller of claim 16, configured to:

analyse the image data to determine at least one of an age and gender of the vehicle occupant; and adjust or select a value for the threshold value in dependence on the determined at 25 least one of age and gender of the vehicle occupant.

19. The controller of any of claims 11 to 18, configured to:

receive data indicative of the one or more dynamic properties of the vehicle; and determine, in dependence on the data, a motion sickness dose value of the vehicle 30 occupant;

20. The controller of claim 19, configured to determine the threshold value in dependence on 35 a predetermined threshold motion sickness dose value.

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21. The controller of any of claims 11 to 20 wherein the dynamic properties of the vehicle comprise one or more of:

a yaw of the vehicle;

5 a pitch of the vehicle;

a roll of the vehicle;

a velocity of the vehicle; and an acceleration of the vehicle.

10 22. A system comprising:

the controller of any of claims 11 to 21;

the one or more sensors; and the display unit.

15 23. The system of claim 22 comprising a camera configured to capture an image of the vehicle occupant

24. The system of any of claims 22 to 23, wherein the display unit comprises at least one of:

a projector configured to project the datum on one or more interior surfaces of the 20 vehicle; and one or more display screens disposed inside the vehicle.

25. The system of any of claims 22 to 24, comprising a first portable electronic device, wherein the portable electronic device comprises at least one of the one or more sensors.

26. The system of claim 25, wherein the first portable device is a wearable device.

27. The system of claim 25 or claim 26, wherein the first portable device comprises the controller.