WO2023066495A1

WO2023066495A1 - Air purification system

Info

Publication number: WO2023066495A1
Application number: PCT/EP2021/079283
Authority: WO
Inventors: Waad NASSAR
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2021-10-21
Filing date: 2021-10-21
Publication date: 2023-04-27
Anticipated expiration: 2024-04-21
Also published as: GB2627121A; GB202406796D0

Abstract

An air purification system for a cabin (12) of a vehicle (10), the cabin (12) comprising at least one seat arrangement (30, 32) including one or more vehicle seats (30a, 30b, 32a, 32b), the air purification system comprising an ionisation device (48, 60) mountable in a position within the vehicle (10) to impact air quality in a region of the vehicle cabin (12); and a control system (14) comprising one or more controllers (16), the control system being configured to receive at least one sensor signal (140-154), from one or more sensors of the vehicle (10), indicative of an air quality characteristic indicative of air quality in a region associated the vehicle (10), and to generate a control signal (190) to activate the ionisation device (48, 60) in dependence on the received sensor signal.

Description

AIR PURIFICATION SYSTEM

Technical Field

The present disclosure relates to an air purification system for use in a vehicle. Aspects of the invention relate to a controller, to a method, to a vehicle, and to a non-transitory, computer-readable medium.

Background

Air quality is becoming an increasingly important issue in the world around us. In the automotive industry, for example, customer awareness of air quality within the vehicle cabin, and the impact on health and well-being, is known to influence the customer's buying decision. Whether for business or recreation purposes, some vehicle users can spend a significant amount of time, on a daily basis, within the vehicle cabin and the requirement for a clean and healthy environment is paramount.

It is known to provide multiple air quality control features in some vehicles, including features to filter particulate matter, harmful gases, viruses, bacteria and allergens, as well as odour and volatile organic compounds. The challenge for the vehicle manufacturer is to implement adequate air quality control features to satisfy users' awareness and concern for air quality, but to optimise systems so that they run efficiently together and with intuitive control for users. In a climate where vehicles are provided with an increasing number of technical features and accessories, ease of use by the user cannot be ignored.

It is against this background that the present invention has been devised.

Summary of the Invention

According to an aspect of the present invention there is provided an air purification system for a cabin of a vehicle, the cabin comprising at least one seat arrangement including one or more vehicle seats, the air purification system comprising an ionisation device mountable in a position within the vehicle to impact air quality in a region of the vehicle cabin associated with a seat arrangement; and a control system comprising one or more controllers, the control system being configured to receive at least one sensor signal, from one or more sensors of the vehicle, indicative of an air quality characteristic indicative of air quality in a region associated with the vehicle, and to generate a control signal to activate the ionisation device in dependence on the received sensor signal. Reference to the air quality characteristic is taken to mean any characteristic that is representative of the concentration level of some form of particulate matter or harmful gas within the air environment (e.g. carbon dioxide or volatile organic compound) or air quality comfort indicators (e.g. temperature or humidity).

The air purification system provides the advantage that the environment within the vehicle cabin can be kept clean automatically, without the need for user-input in controlling, for example, filters and ionisers, creating a more pleasant and clean environment for use and without distraction to occupants of the vehicle.

By way of example, the one or more controllers collectively may comprise at least one electronic processor having an electrical input for receiving the or each sensor signal; and, at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein, wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to generate the control signal to activate the or each ionisation device based on the air quality characteristic from the or each received sensor signal.

In one embodiment, the control system may be configured to receive the sensor signal from a particulate sensor mounted externally to the vehicle cabin, the sensor signal being indicative of a level of particulate matter in the air outside the vehicle cabin.

Typically, the air quality characteristic indicated by at least one of the sensor signals may be a concentration level of particulate matter in the air outside the vehicle. The control system may be configured to generate the control signal to activate the or each ionisation device if the concentration level is above a predetermined exterior particulate threshold concentration level.

The concentration level may be the concentration of one or more of a sulphur oxide, a nitrogen oxide and carbon monoxide.

The controller may be configured to receive the sensor signal from an interior particulate matter sensor (a sensor mounted inside the vehicle cabin) which is indicative of a level of particulate matter within the vehicle cabin.

Interior and exterior sensors may be provided, and output signals may be provide from both types of sensor to the controller. By way of example, the air quality characteristic indicated by at least one of the sensor signals may be a concentration level of particulate matter in the air within the vehicle cabin. The control system may be configured to generate the control signal to activate the or each ionisation device if the air quality level is above a predetermined interior particulate threshold concentration level.

The controller may be configured to receive the sensor signal from a carbon dioxide sensor which is indicative of a carbon dioxide concentration level within the vehicle cabin.

According to another aspect the invention provides a vehicle comprising a control system, according to any preceding paragraph, the vehicle comprising the vehicle cabin, the or each seat arrangement, and the one or more sensors.

For example, the seat arrangement may comprise a first row of one or more seats in the front of the vehicle and a second row of one or more seats behind the first row of seats.

In one embodiment, the air purification system may comprise a first ionisation device mounted or mountable in a front position within the vehicle to impact air quality in a first region of the vehicle cabin associated with the first row of vehicle seats, a second ionisation device mountable in a rear position within the vehicle to impact air quality in a second region of the vehicle cabin associated with the second row of vehicle seats. The control system may be configured to generate a control signal to activate the first ionisation device and/or the second ionisation device in dependence on the received sensor signal indicative of the air quality characteristic. The vehicle may comprise at least a first user input device configured to receive a first user command from a user in the first row of seats. The control system may be configured to receive the first user command and generate a user-generated control signal in response to the first user command to operate the air purification system in a first mode of operation in which both the first ionisation device and the second ionisation device are activated together, even if the control signal to activate the first ionisation device and the second ionisation device, based on the air quality characteristic from the received sensor signal, is not generated.

The air purification system may also comprise a second user input device locatable in the rear of the vehicle cabin so as to be operable by a user in the second row of seats to receive a second user command. The control system may be configured to receive the second user command and generate a user-generated control signal in response to the second user command to operate the air purification system in the first mode of operation, even if the control signal to activate the first ionisation device and the second ionisation device, based on the air quality characteristic from the received sensor signal, is not generated.

According to another aspect, there is provided a method of controlling an air purification system for a cabin of a vehicle, the cabin comprising at least one seat arrangement including one or more vehicle seats, the method comprising mounting an ionisation device in a position within the vehicle to impact air quality in a region of the vehicle cabin; receiving, at a control system, at least one sensor signal, from one or more sensors of the vehicle which is indicative of an air quality characteristic indicative of air quality associated with the vehicle; and generating a control signal to activate the ionisation device in dependence on the received sensor signal.

The vehicle may comprise a first user input device configured to receive a first user command from a user, and the method may comprise receiving, at the control system, the first user command and generating a usergenerated control signal in response to the first user command to activate the ionisation device, even if the control signal to activate the ionisation device based on the air quality characteristic from the received sensor signal is not generated.

The benefit of the method is that it provides the user with the option to override the automated control of the ionisation device(s) through their own input commands.

According to another aspect the invention provides a no n-transitory , computer-readable storage medium storing instructions thereon that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out the method according to the preceding paragraph.

Any control unit or controller described herein may suitably comprise a computational device having one or more electronic processors. The system may comprise a single control unit or electronic controller or alternatively different functions of the controller may be embodied in, or hosted in, different control units or controllers. As used herein the term "controller” or "control unit” will be understood to include both a single control unit or controller and a plurality of control units or controllers collectively operating to provide any stated control functionality. To configure a controller or control unit, a suitable set of instructions may be provided which, when executed, cause said control unit or computational device to implement the control techniques specified herein. The set of instructions may suitably be embedded in said one or more electronic processors. Alternatively, the set of instructions may be provided as software saved on one or more memory associated with said controller to be executed on said computational device. The control unit or controller may be implemented in software run on one or more processors. One or more other control unit or controller may be implemented in software run on one or more processors, optionally the same one or more processors as the first controller. Other suitable arrangements may also be used.

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 shows a schematic illustration of a vehicle including an air purification system according to an example of the invention;

Figure 2 shows a schematic illustration of the control system of the air purification system Figure 1 ;

Figure 3 shows a top plan view of vehicle cabin to illustrate an example seating arrangement of the vehicle in Figure 1 ;

Figure 4 is a perspective view of an instrument panel in the vehicle cabin of Figure 3, to illustrate the position of a first ionisation device of the air purification system;

Figure 5 is an enlarged perspective view of the ionisation device in Figure 4;

Figure 6 is a top view of the vehicle cabin in Figure 3 to illustrate the position of a filtration system;

Figure 7 is a perspective view of air ducting and the first ionisation device in Figures 4 and 5;

Figure 8 is a perspective view of a centre console of the vehicle cabin in Figure 3, to illustrate the position of a second ionisation device of the air purification system; Figure 9 is an isolated perspective view of a part of the centre console housing in Figure 8 to illustrate the second ionisation device;

Figure 10 is a perspective view of an alternative arrangement to that in Figure 9 to illustrate alternative ducting for the second ionisation device;

Figure 11 is a perspective view from the rear of an instrument panel of the vehicle to illustrate the position of an internal sensor of the air purification system;

Figure 12 is a perspective view from the front side of the vehicle (leaf screen) to illustrate the position of an external sensor (external to the vehicle cabin) of the air purification system;

Figure 13 is a schematic illustration of the controller to show the signals received by and output from the controller to control the air purification systems in various modes of operation;

Figure 14 is a schematic illustration of the various modes of operation in Figure 13, to illustrate the sensor signals utilised by each mode;

Figure 15 is a schematic illustration of a first user input arrangement for the air purification system; and

Figure 16 is a schematic illustration of a second user input arrangement for the air purification system.

Detailed Description

An air purification system in accordance with an embodiment of the present invention will now be described with reference to the accompanying figures.

Figure 1 shows a vehicle 10 in the form of a car. The vehicle 10 has a vehicle cabin 12. The vehicle 10 includes the air purification system for controlling the quality of air within the vehicle cabin 12. The air purification system includes several features located in various positions around the vehicle and within the vehicle cabin 12. The air purification system includes a control system, represented schematically as item 14, comprising one or more controllers. The controller may be located in any position within the vehicle and it will be appreciated that the position shown in Figure 1 is illustrative only. The vehicle in Figure 1 is a left-hand drive vehicle with the steering wheel 15 on the left-hand side of the vehicle cabin 12. Referring to Figure 2, the one or more controllers 16 of the control system 14 comprise at least one electronic processor 18 having an electrical input for receiving sensor output signals and user commands (represented generally as 20); and at least one memory device 22 electrically coupled to the at least one electronic processor 18 and having instructions stored therein; wherein the at least one electronic processor 18 is configured to access the at least one memory device 22 and execute the instructions thereon so as to generate output control signals 24 in response to the user commands which are sent to the air purification system to operate the system in various different modes of operation, as will be described in further detail below. The input of the or each controller is configured to receive data from a plurality of sources. Specifically, as will be explained in more detail later, the input may be configured to receive sensor output signals and a user input command which is input by the user via a user input arrangement (not shown in Figure 2). The user input arrangement will be described in further detail below.

It is to be understood that the or each controller 16 can comprise a control unit or computational device having one or more electronic processors (e.g., a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), etc.), and may comprise a single control unit or computational device, or alternatively different functions of the or each controller may be embodied in, or hosted in, different control units or computational devices. As used herein, the term "controller,” "control unit,” or "computational device” will be understood to include a single controller, control unit, or computational device, and a plurality of controllers, control units, or computational devices collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause the or each controller to implement the control techniques described herein (including some or all of the functionality required for the method described herein). The set of instructions could be embedded in said one or more electronic processors of the controller (s); or alternatively, the set of instructions could be provided as software to be executed in the controller(s). A first controller or control unit may be implemented in software run on one or more processors. One or more other controllers or control units may be implemented in software run on one or more processors, optionally the same one or more processors as the first controller or control unit. Other arrangements are also useful.

The or each electronic processor 18 may comprise any suitable electronic processor (e.g., a microprocessor, a microcontroller, an ASIC, etc.) that is configured to execute electronic instructions. The or each electronic memory device 22 may comprise any suitable memory device and may store a variety of data, information, limit value(s), lookup tables or other data structures, and/or instructions therein or thereon. In an embodiment, the memory device 22 has information and instructions for software, firmware, programs, algorithms, scripts, applications, etc. stored therein or thereon that may govern all or part of the methodology described herein. The or each electronic processor 18 may access the memory device 22 and execute and/or use that or those instructions and information to carry out or perform some or all of the functionality and methodology describe herein.

The at least one memory device 22 may comprise a computer-readable storage medium (e.g. a non-transitory or non-transient storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors/computational devices, including, without limitation: a magnetic storage medium (e.g. floppy diskette); optical storage medium (e.g. CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g. EPROM and EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

Referring to Figure 3, inside the vehicle cabin 12 there is provided a first seat arrangement, referred to generally as 30, and a second seat arrangement, referred to generally as 32. The first seat arrangement 30 takes the form of a first row of two front seats 30a, 30b located in a relatively forward position in the vehicle. The first row of front seats includes a passenger's seat 30a on the right hand side of the vehicle and a driver's front seat 30b on the left hand side of the vehicle. In other configurations the driver's seat may be on the right hand side of the vehicle as opposed to the left. A centre console 34 is arranged between the left and right side front seats 30a, 30b of the first row. Conveniently the centre console 34 has a flat upper surface suitable for providing a rest surface for an occupant's arm. The centre console 34 may also provide storage space beneath a lid of the console. The centre console 34 also houses features of a vehicle ventilation system, including left and right side air vents (not shown in Figure 3), which are located in a rear-facing surface of the centre console 34 to direct air towards, and impact the environment of, occupants seated behind the first row of seats 30.

Rearward of the first row of seats 30, the second seat arrangement 32 takes the form of a second row of three rear seats 32a, 32b, 32c; a rear right seat 32a, a rear left seat 32b and a centre seat 32c. The rear left seat 32b is generally located rearward of the front left seat 30b and the rear right seat 32a is generally located rearward of the front right seat 30a. The centre rear seat 32c is located generally rearward of the front centre console 34. In a known manner, a rear drop-down platform 36 is located over the centre rear seat 32c when the platform is pivotally dropped down from an upright position in which the platform is stowed in a recess (not shown in Figure 3) in the rear seat arrangement 32.

In front of the front row of seats 30 is a vehicle dashboard which includes an instrument panel (not visible in Figure 3) housing various displays and controls which are accessible to occupants of the vehicle to control and observe various vehicle functions. Referring to Figures 4 and 5, the instrument panel 40 is shown in more detail. For example, the instrument panel 40 may house an audio system control, a navigation system control and/or a heating system control. The control system 14 for any or all of the system functions is controlled via the instrument panel is represented in Figure 3 as being behind the instrument panel 40, but it will be appreciated that the one or more controllers of the instrument panel may be located anywhere in the vehicle, and not necessarily behind the instrument panel 40. The instrument panel 40 is provided with a plurality of front air vents 42a, 42, 42c. Fresh air from outside the vehicle, and recirculated air from within the vehicle, can be introduced to or recirculated within the vehicle cabin 12 via the front air vents 42a, 42b, 42c. Further air vents may also be provided in regions of the instrument panel 40 which are not visible in Figure 5.

Referring also to Figure 6, air is delivered into the cabin through the air vents 42a, 42b, 42c via a filtration system including a main filter 43 for filtering particulates from the air and a pre-filter 45 upstream of the main filter 43. The main filtration system 43, 45 communicates with the air vents 42a, 42b, 42c through front air ducting (not shown). The main filter 43 typically includes a particulate filter for filtering particles from the airflow having a size up to 2.5pm in size. This may be referred to as a "PM2.5” filter. The pre-filter 45 may filter particles having a size up to 10 pm in size. This may be referred to as a "PM10” filter. The PM2.5 filter 43 may be provided with an anti-allergen coating technology which is proven to cause viruses and allergens to deactivate, providing further advantages for virus control within the vehicle cabin 12. One or more PM2.5 filters may be provided within the vehicle. The PM2.5 filter(s) may also be provided with an active carbon layer for substantially reducing odour and other harmful gases.

The filtration system 43, 45 supplies a filtered air flow via front air ducting through the air vents 42a, 42b, 42c in the instrument panel 40 and also through rear air ducting 47 in the centre console 34 to be expelled through air vents 66a, 66b (described in further detail below) provided in the centre console 34. The filtration system is operable in various modes including a fresh air mode and a recirculation mode, with the mode being selected in dependence on the outputs from various sensors associated with the vehicle, as described in further detail below.

The air flow from the front vents 42a, 42b, 42C is mainly concentrated in the front row seats 30 (this zone is referred to as the front occupant space). Some of this air is also carried over to the second row seats 32, at a lower velocity. Three front air vents 42a, 42b, 42c are shown in Figure 4, two of which 42a, 42b are associated with the left hand front passenger seat 30b and one of which 42c is associated with the right hand front seat 30a. A fourth air vent (not shown) is also provided for the right hand front seat 30b. Adjustable fins (for example 43) of the air vents 42a, 42b, 42c allow the direction of the airflow into the front occupant space to be adjusted. The instrument panel 40 includes a top cover 44 including a raised portion 46 which is located forward of the front right seat 30a. A first air purifier device 48 in the form of an OH (hydroxyl) radical generator device (also referred to as an ionisation device) is mounted in a first position within the vehicle to impact or influence air quality in a first region of the vehicle cabin 12 associated with the first seat arrangement 30. The first ionisation device 48 in the present embodiment is mounted beneath the raised portion 46 via mounting portions 50, 52 which are attached to an internal frame of the instrument panel 40 by means of screws 54, 56. The first ionisation device 48 uses the Nanoe™ X technology which uses a high voltage to create trillions of Hydroxyl (OH ) radicals enveloped in nano sized water molecules. These OH radicals deactivate pathogens by breaking down virus and bacteria proteins which helps to inhibit their growth. As well as combating pathogens, the OH radicals also act upon odour molecules and allergens in a similar way.

Referring also to Figure 7, the first ionisation device 48 includes an air inlet (not shown) and an air outlet (also not shown) which communicates with an outlet tube 51 of the first ionisation device 48. The first ionisation device 48 is configured to draw air in through the inlet from the surroundings and then emits OH radicals through the outlet into the outlet tube 51 which communicates with the front air ducting 53. As the front air ducting 53 is arranged to receive the filtered flow of air through the main filtration system 43, 45, this means that the OH radicals are mixed with the filtered air flow in the ducting 53 and together the filtered air flow and the OH radicals are delivered through the air vents 42a, 42b, 42c (one of which 42a is identified in Figure 7) into the front occupant space. The first ionisation device 48 therefore impacts mainly the air quality in a first zone or region of the vehicle, being the front occupant space. The first zone or region of the vehicle cabin 12 is associated with the first seat arrangement 30.

The adjustable fins 43 of the air vents 40 then allow the direction of the airflow into the front occupant space to be adjusted.

Referring to Figures 8 to 10, a second air purifier device 60 in the form of a second OH (hydroxyl) radical generator device (also referred to as an ionisation device) is mounted in a second position within the vehicle to impact or influence air quality in a second region of the vehicle cabin 12 associated with the second seat arrangement 32. The second ionisation device 60 in the present embodiment is mounted in the centre console 34 which is located between the right and left front seats 30a, 30b of the first row of seats. The second ionisation device 60 may take the same form as the first ionisation device which uses the Nanoe™ X technology.

The centre console 34 includes a rear-facing panel 62 which is provided with an opening for receiving an air vent mounting 64. The air vent mounting 64 houses left and right-side adjustable vents 66a, 66b respectively (as seen in Figure 8), through which a filtered airflow, filtered by the vehicle's filtration system, is delivered to or recirculated within the cabin 12. The air vents 66a, 66b direct air flow towards the cabin space or zone immediately in front of, and in the volume surrounding, occupants of the rear row of seats 32 (referred to as the rear occupant space). Adjustable fins 70 of the air vents 66a, 66b allow the direction of the airflow into the rear occupant space to be adjusted by the occupant. The second ionisation device 60 therefore impacts the air quality in a second zone or region of the vehicle, being the rear occupant space. The second zone or region of the vehicle cabin 12 is associated with the second seat arrangement 32.

The second ionisation device 60 is mounted behind the air vents 66a, 66b within the centre console 34. The second ionisation device includes an output tube 72 through which the ionised air flow is dispelled from the device 60 into the rear air ducting 47 where it combines with the filtered air flow. The output tube 70 projects up through an opening in the air vent frame 64 to deliver the filtered, ionised air flow out through the left side air vent 66a. The second ionisation device 60 may be mounted in the centre console 34 together with padding/damping material (not shown) which serves to damp noise, vibration and harshness (NVH) effects. In another arrangement, as shown in Figure 10, the output tube 172 has a more convoluted construction before its exit point through the opening in the air vent frame 64. The arrangement in Figure 10 has been observed to benefit NVH. Padding/damping material may also be accommodated within the arrangement of Figure 9.

The filtration system is operable in at least two functions. In a "recirculation” mode of operation (also referred to as the "Purify” mode of operation) the air in the vehicle does not pass through the pre-filter 45 (PM 10) but instead will pass many times (being recirculated) through the main filter 43 (PM2.5), whilst being dispelled into the cabin 12 via the various vents, giving a quicker and better filtration efficiency. In a fresh air mode of operation (where the recirculation function is not active), the air enters the vehicle from outside the vehicle and passes through the pre filter (PM10) and the main filter (PM2.5) once before entering the cabin via the various vents. Details of the different functions for the filtration system are described in further detail below.

The air purification system also includes a carbon dioxide management device (not shown) which is configured to manage the levels of carbon dioxide within the vehicle cabin dependent on control by the user and/or optionally based on feedback from a carbon dioxide sensor.

The controller 14 for the air purification system is arranged to receive a combination of sensor signals which are derived from a plurality of vehicle sensors for measuring various air quality characteristics indicative of air quality in a region associated with the vehicle (i.e. a region inside and/or outside the vehicle cabin). The air quality characteristics may, for example, include one or more of the following: the concentration of particles and/or gases, the temperature of air associated with the vehicle, and/or misting on the vehicle windows. The sensor signals are derived from sensors mounted internally and externally to the vehicle cabin to measure various air quality parameters (AQPs) inside and outside the vehicle. The controller 14 may also receive user commands from users inside or outside the vehicle. In response to the sensor signals that are indicative of the air quality characteristics, and optionally in response to the user commands, the air purification system is controlled by means of control signals generated by the controller 14. The controller generates a "signal- generated” control signal in response to the sensor output signal (s) to operate various features of the air purification system in an automated way, without requiring user-input, and optionally may include the facility for the user to input commands which result in the controller 14 generating a "user-generated” control signal to control the various features of the air purification system.

Referring to Figure 11 , the vehicle is typically fitted with a combined particle and carbon dioxide sensor 80 which is mounted inside the vehicle, behind the instrument panel 40. The combined particle and carbon dioxide sensor 80 is arranged to detect the concentration level of particles in the cabin (with a size up to 2.5pm) that can cause illness, irritation, allergic reaction, and which can also harbour viruses. The sensor 80 also measures the concentration level of carbon dioxide in the cabin. Exposure to carbon dioxide can produce a variety of adverse health effects, including headaches, dizziness and drowsiness and so it is beneficial to measure this and operate the air purification system in response, to reduce the risk of these effects Typically, the sensor 80 may be referred to as a "PM2.5 sensor”. The output from the combined particle and carbon dioxide sensor 80 is provided as a first input to the air purification system controller 14.

Referring to Figure 12, the vehicle may also be fitted with particle sensor 90 mounted externally to the vehicle cabin 12. The sensor 90 is fitted on the left hand side of the vehicle (looking from the outside into the vehicle cabin 12) and typically measures the concentration level of particles in the air flow as it enters the vehicle, with particles having a diameter of up to 2.5 pm. Typically, the sensor 90 may be referred to as the external "PM2.5 sensor”. The output from the particle sensor 90 outside the vehicle is provided as a second input to the air purification system controller 14. The mounting of the sensor 90 externally to the vehicle cabin may include mounting the sensor 90 externally to the cabin but still within the outer shell of the vehicle itself (e.g. under the bonnet), or mounting of the sensor on an externally-facing surface of the vehicle outside of the vehicle shell.

The air purification system controller 14 receives the signals from the various sensors 80, 90 (and any further sensors) and, in response to the sensor signals, controls features of the air purification system relating to the recirculation function. For example, the main filter 43 and the pre-filter 45 are controlled in response to the sensor signals so as to switch between the recirculation mode and the fresh air mode, automatically selecting the most appropriate mode.

One or more further air quality sensors (not shown) may be provided on the vehicle, either inside or outside the vehicle cabin. For example, sensors may be provided in the form of bacteria sensors, virus sensors, volatile organic compound sensors or sensors for measuring the presence of harmful gases within the environment (e.g. a carbon monoxide sensor). A temperature sensor (not shown) may also be provided in the vehicle cabin to measure the cabin temperature. A further air quality sensor may also be provided to detect temporary increases in harmful gases.

Referring to Figure 13, the controller is configured to control the air purification system in at least three modes of operation, in dependence on the outputs from the various sensor signals. The controller 14 is programmed with suitable logic to apply the most appropriate mode, according to the sensor output signals it receives. The air purification system has a "Purify” mode control logic (represented by box 200), an "Ionisation” mode control logic (represented by box 202) and a "CO2” mode control logic (as represented by box 204). The control logic is implemented as a set of instructions which, when executed, cause the or each controller 14 to implement the control techniques described herein. The set of instructions could be embedded in one or more electronic processors of the controller(s); or alternatively, the set of instructions could be provided as software to be executed in the controller(s).

In the Purify mode, the carbon dioxide management device, the first ionisation device 48, the second ionisation device 60 and the main filter 43 may all be activated together.

In the Ionisation mode only the first and second Ionisation devices 48, 60 are activated (without the main filter and the carbon dioxide management device) and in the CO2 mode only the carbon dioxide management device is activated (without the first and second ionisation devices 48, 60 and the main filter 43).

In general, the sensor signals provided to the controller 14 for the purpose of executing the control logic 200, 202, 204 include (but are not limited to); an output signal 140 from the internal PM2.5 sensor 80 (as shown in Figure 8), an output signal 142 from the external PM2.5 sensor 90 (as shown in Figure 9), an output signal 144 from an air quality sensor (AQS) for detecting harmful gas (typically a harmful gas such as carbon monoxide), an output signal 146 from a mist sensor detecting misting on the vehicle windscreen, an output signal 148 from an occupancy sensor detecting vehicle occupancy, an output signal 150 from a temperature sensor for detecting the temperature within the vehicle cabin, an output signal 152 from a vehicle ventilation sensor, and an output signal 154 from a carbon dioxide sensor.

The controller 14 also receives one or more signals 156 derived from one or more user input command(s), as described in further detail below.

The ventilation sensor is a sensor which provides an indication of the blower (fan) speed and, hence, the speed of air flow within the vehicle cabin. The ventilation sensor output signal is input to the controller 14 because it is necessary to ensure that the ionisation device(s) are controlled so as to have sufficient time to react to the virus deactivation.

In response to the input signals 140-154 received from the various sensors associated with the vehicle, and optionally the user-input command, the controller 14 selects the most appropriate mode of operation and provides an output control signal 190 to control the corresponding features of the air purification system (e.g. filtration system operation mode, ionisation devices 48, 60, carbon dioxide management device) so as to influence the air quality within a region of the vehicle cabin 12. The controller also provides output signals, 170, 172, 174, to the user interface device 180 for displaying information to the user about the operational mode which has been activated.

The manner in which the various modes of operation are implemented by the controller 14 will now be described in further detail with reference to Figure 14.

The Purify mode is activated in dependence on the gas sensor signal 144, the mist sensor signal 146, the PM2.5 sensor signal and the carbon dioxide sensor signal 154. As described previously, the Purify mode of operation activates both the first and second ionisers 48, 60 together, as well as the carbon dioxide management device and the main filter 43. If the gas sensor signal indicates that the level of harmful gas within the vehicle cabin exceeds a predetermined concentration level, the Purify mode is activated by the Purify mode control logic 200 on the controller 14, hence turning on the first and second ionisation devices 48, 60, the carbon dioxide management device and the main filter 43. The mist sensor is also a condition input for the operation of the Purify mode 200, and impacts on the performance of the Purify function as it results in a request for fresh air filtration mode. Finally, if the PM2.5 sensor signal indicates that the level of particulate matter within the cabin 12, or outside the vehicle cabin 12, exceeds a predetermined concentration level, the Purify mode control logic 200 generates a control signal to activate the Purify mode.

The Purify mode is also activated if the user requests this by issuing an appropriate user input command 156.

An output is provided from the Purify mode control logic 200 which is indicative of the status of the Purify mode (either ON or OFF), and this is provided to the 002 mode control logic 204. If the Purify mode is ON (i.e. the Purify mode has been activated), the 002 mode control logic 204 sends an output signal to activate the carbon dioxide management device (as required in Purify mode).

A temperature signal is also provided to the 002 mode control logic 204. The carbon dioxide management device requests fresh air for a certain amount of time to lower the concentration level of carbon dioxide in the vehicle cabin to a very restrictive target concentration level of 2000ppm.ln some conditions, for example in a high temperature environment, if fresh air is introduced into the cabin for too long then the occupants may feel discomfort. Hence, the CO2 mode control logic 204 is dependent on the temperature to reduce such discomfort effects.

The CO2 mode is also activated in response to a user input command to request that the carbon dioxide management device is turned on, even if the sensor outputs do not dictate that this is required.

A start/stop signal 192 is also provided to the CO2 mode control logic 204. At the start/stop condition, some external odour may be generated by the vehicle and these odours can get into the vehicle cabin if the fresh air function is activated at this time. The start/stop signal 192 is therefore used to control the carbon dioxide management device at the start/stop time so as to avoid this happening. By taking into account the start/stop signal 192, the time that fresh air is put into the cabin is managed so as to improve user comfort around the start/stop condition, whilst still preventing excess carbon dioxide concentration levels building up which can cause drowsiness.

The output from the Purify mode control logic 200 which is indicative of the status of the Purify mode (either ON or OFF) is also provided to the Ionise mode control logic 202. If the Purify mode is on (i.e. the Purify mode has been activated), the Ionise mode is activated by the Ionise mode control logic such that the first and second ionisers 48, 60 are both activated together. The Ionise mode control logic 202 may in some embodiments be responsive to the ventilation signal 152 from the ventilation system.

An occupancy sensor signal 194 is also provided to the Ionise mode control logic 202 so that the Ionise mode is activated depending on the occupancy within the vehicle (e.g. whether or not an occupant is seated in the front row of seats only, or whether an occupant is seated in the rear row of seats as well). Typically, the occupancy sensor signal may be derived from a weighing system associated with each vehicle seat which provides an indication of whether the particular seat is occupied.

The Ionise mode control logic 202 can also be activated on receipt of a user command signal 156 by the Ionise mode control logic 202.

Referring to Figure 15, the user interface device 180 may include a user input arrangement in the form of a touch-sensitive input device 100, which is configured to receive user commands from an occupant or user of the vehicle. The instrument panel 40 at the front of the vehicle 10 accommodates the input device 100 which includes a display region 102 and a user input region 104. The display region 102 displays a plan view 106 of the vehicle and provides an indication to the vehicle occupants of the air quality distribution throughout the vehicle cabin 12, based on measurements relating to the outputs 140-150 from the various sensors (e.g. sensors 80, 90). The display region 102 also includes a sliding scale 108 which represents the air quality distribution in the plan view 106.

The user input region 104 includes a plurality of user input elements 110, 112, 114 in the form of touch-sensitive regions for receiving a user command to control the various functions of the air purification system. By way of example, the first input element 110 is configured to activate the Purify mode of operation and the carbon dioxide management device, as well as the first and second ionisation devices 48, 60. When the first input element 110 is activated by the user, the first and second ionisation devices 48, 60 are therefore turned on together with the PM2.5 filter and the carbon dioxide management device. This is the "Purify” mode 200 of the system, as referred to previously, and where all four devices may be activated simultaneously (first and second ionisation devices 48, 60, carbon dioxide management device and main filter 43). In this case the air is recirculated within the vehicle cabin 12 without drawing in new fresh air supply from outside the vehicle.

The second input element 112 is configured to control the first and second ionisation devices 48, 60, so that when it is activated only the first and second ionisation devices 48, 60 are activated but not the carbon dioxide management devicer This may be referred to as the "Ionise” function of the system, which does not turn on the Purify function (whether recirculation mode or fresh air mode).

The third input element 114 is configured to control only the carbon dioxide management device so that when it is activated only the carbon dioxide management device is activated. The fourth input element 116 is operated by the user when it is desired to access air quality data (e.g. pollutants) received over a wireless network (e.g. cloud-based data), for example relating to the air quality in the area surrounding the vehicle or in the area at a destination for the vehicle.

The input device 100, being located in the front of the vehicle, is referred to as the front user input arrangement and is located to allow convenient operation by users of the vehicle occupying the first row of seats. The input device 100 is typically a wired device which connects to the controller 14 through electrical wiring. In other embodiments, the front user input arrangement may be a Bluetooth® device which connects the controller via a wireless connection.

The second ionisation device 60 is located in the centre console 34 and is configured to direct a purified air flow into the zone associated with occupants of the vehicle in the rear row of seats 32, impacting the rear occupant space. As described previously, operation of the second ionisation device 60 in combination with the first ionisation device 48 may be operated by an occupant in the front row of seats operating either the first or second user input element 110, 112. Furthermore, because the second ionisation device 60 is accommodated within the front centre console 34, and is configured to direct a clean airflow into the rear occupant space, the air quality distribution within the vehicle cabin is of a much more homogeneous nature compared to vehicles having only one ionisation device behind the front instrument panel.

In addition to the front user input device 100 for occupants of the vehicle in the front seats 30, the occupants in the rear row of seats 32 are provided with a rear user input arrangement or device 120 which can be used to control functions of the air purification system in the same way as the front user input device 100. The operation of the first ionisation device 48 and the second ionisation device 60 can be selectively controlled in dependence on operation of the front user input device 100 and/or the rear user input device 120. The front user input device 100 and the rear user input device 120 are configured to receive user commands to control operation of the first ionisation device 48 and the second ionisation device 60. Operation of the second ionisation device 60 in combination with the first ionisation device 48 may be activated by means of the user elements of the second user input device 120. This provides maximum convenience of use for the vehicle users and avoids the need for the driver of the vehicle to be the only one controlling the air purification functions. In more detail, and referring to Figure 15, the user input device 120 for the rear row of seats 32 includes first and second user input elements, 122, 124 respectively, in the form of first and second touch-sensitive regions. The first user input element 122 of the rear user input device 120 is configured to control the carbon dioxide management device and the main filter system, as well as the first and second ionisation devices 48, 60. When the first user input element 122 is activated by the user, the first and second ionisation devices 48, 60 are therefore turned on together with the carbon dioxide management device and the main filter in a recirculation mode. This is the "Purify” function of the system described previously, where all four devices are activated simultaneously. The first input element 122 of the rear user input device 120 therefore has the same functionality as the first input element 110 of the front user input device 100.

The second user input element 124 of the rear user input device 120 is configured to control the first and second ionisation devices 48, 60, so that when it is activated only the first and second ionisation devices 48, 60 are activated, but not the filtration system. This may be known as the "Ionisation” function of the system. The second user input element 124 of the rear user input device 120 therefore has the same functionality as the second input element 112 of the front user input device 100.

The provision of the rear user input device 120 provides convenience for the vehicle users and means that the responsibility for operation of the air purification system can be passed to occupants in the rear of the vehicle whilst the driver may be otherwise engaged.

Conveniently, and as illustrated in Figure 15, the rear user input device 120 may take the form of a mobile input device, such as a personal tablet, which communicates with the controller 14 via a wireless (e.g. Bluetooth®) connection. The personal tablet may be mountable within a suitable mount provided on the rear centre console (36 - as in Figure 3) or may be mountable within the rear-facing surface of one of the seats of the first row 30. In other embodiments, the rear user input device 120 may be a permanent feature in the rear of the vehicle cabin 12, located in a convenient position for operation by the rear-seated occupants. In other embodiments, the rear user input device 120 may be a wired device which is located within the vehicle permanently. Whatever the connectivity function, the location of the rear input device 120 is selected to be accessible conveniently by a user of the vehicle so that the controls of the rear input device 120 are suitable for use by an occupant in the rear of the vehicle.

As well as the first and second user input elements 122, 124, the mobile input device 120 includes first, second and third controls 126, 128, 130 for selecting to display information about, or control, features relating to the climate within the vehicle, the vents within the vehicle and the air quality within the vehicle, respectively. In the illustration shown the air quality function is selected to display the first and second user input elements 122, 124 for the "Purify” function and the "Ionisation” mode of the system.

In other embodiments, the air purification system may be operable remotely from the vehicle via a user input device (such as the mobile tablet 120) which may be carried by a vehicle user. For example, in advance of getting into the vehicle, the user may operate a user input device 120 to activate whichever features of the air purification system are required, before entering the vehicle. The system may be activated on approach to the vehicle, or alternatively may be activated when the user is at home and some time prior to entering the vehicle, allowing the vehicle cabin to be fully prepared with a clean and homogenous air quality environment before entry. In other embodiments, prior to leaving the vehicle the user may activate an air purification function such that once the car is locked and empty of users, an air quality deep cleaning cycle (removal of virus, harmful gases etc), may be initiated to cleanse the cabin environment prior to next use.

The activation of the air purification system, and the first and second ionisation devices 48, 60, may override the automatic control of the devices so that the user can command activation even if the sensor outputs do not result in automatic activation.

It will be appreciated that various other embodiments of the air purification system are envisaged without departing from the scope of the accompanying claims.

Claims

1 . An air purification system for a cabin of a vehicle, the cabin comprising at least one seat arrangement including one or more vehicle seats, the air purification system comprising: an ionisation device mountable in a position within the vehicle to impact air quality in a region of the vehicle cabin; and a control system comprising one or more controllers, the control system being configured to receive at least one sensor signal, from one or more sensors of the vehicle, indicative of an air quality characteristic indicative of air quality in a region associated with the vehicle, and to generate a control signal to activate the ionisation device in dependence on the received sensor signal.

2. An air purification system as claimed in claim 1 , wherein the one or more controllers collectively comprise: at least one electronic processor having an electrical input for receiving the or each sensor signal; and, at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein, wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to generate the control signal to activate the or each ionisation device based on the air quality characteristic from the or each received sensor signal.

3. An air purification system as claimed in claim 1 or claim 2, wherein the control system is configured to receive at least one of the sensor signals from a particulate sensor mounted externally to the vehicle cabin, the air quality characteristic indicated by the sensor signal being a concentration level of particulate matter in the air outside the vehicle cabin.

4. An air purification signal as claimed in claim 3, wherein the control system is configured to generate the control signal to activate the or each ionisation device if the concentration level of particulate matter is above a predetermined exterior particulate threshold concentration level.

5. An air purification system as claimed in claim 4, wherein the particulate sensor is a sensor for measuring the concentration level of one or more of a sulphur oxide, a nitrogen oxide and carbon monoxide.

6. An air purification signal as claimed in any of claims 1 to 5, wherein the control system is configured to receive the sensor signal from an interior particulate matter sensor which is indicative of a concentration level of particulate matter within the vehicle cabin.

7. An air purification signal as claimed in claim 6, wherein the air quality characteristic indicated by at least one of the sensor signals is a concentration level of particulate matter in the air within the vehicle cabin, the control system configured to generate the control signal to activate the or each ionisation device if the concentration level is above a predetermined interior particulate threshold concentration level.

8. An air purification system as claimed in any of claims 1 to 7, wherein the control system is configured to receive the sensor signal from a carbon dioxide sensor which is indicative of a carbon dioxide concentration level within the vehicle cabin.

9. A vehicle comprising an air purification system as claimed in any of claims 1 to 8, the vehicle comprising the vehicle cabin, the or each seat arrangement, and the one or more sensors.

10. A vehicle as claimed in claim 9, the seat arrangement comprising a first row of one or more seats in the front of the vehicle and a second row of one or more seats behind the first row of seats.

11. A vehicle as claimed in claim 10, comprising a first ionisation device mounted in a front position within the vehicle to impact air quality in a first region of the vehicle cabin associated with the first row of vehicle seats, a second ionisation device mountable in a rear position within the vehicle to impact air quality in a second region of the vehicle cabin associated with the second row of vehicle seats, and at least a first user input device configured to receive a first user command from a user in the first row of seats; the control system configured to receive the first user command and generate a user-generated control signal in response to the first user command to operate the air purification system in a first mode of operation in which both the first ionisation device and the second ionisation device are activated together, even if the control signal to activate the first ionisation device (and the second ionisation device, based on the air quality characteristic from the received sensor signal(s), is not generated.

12. A vehicle as claimed in claim 11, comprising a second user input device locatable in the rear of the vehicle cabin so as to be operable by a user in the second row of seats to receive a second user command, the control system configured to receive the second user command and generate a user-generated control signal in response to the second user command to operate the air purification system in the first mode of operation, even if the control signal to activate the or each ionisation device based on the air quality characteristic from the received sensor signal is not generated.

13. A method of controlling an air purification system for a cabin of a vehicle, the cabin comprising at least one seat arrangement including one or more vehicle seats, the method comprising: mounting an ionisation device in a position within the vehicle to impact air quality in a region of the vehicle cabin; and receiving, at a control system, at least one sensor signal, from one or more sensors of the vehicle, which is indicative of an air quality characteristic indicative of air quality associated with the vehicle, and generating a control signal to activate the ionisation device in dependence on the received sensor signal.

14. The method of claim 13, the vehicle comprising a first user input device configured to receive a first user command from a user, the method comprising receiving, at the control system, the first user command and generating a user-generated control signal in response to the first user command to activate the ionisation device, even if the control signal to activate the ionisation device based on the air quality characteristic from the received sensor signal is not generated.