GB2519575A

GB2519575A - Seat heater and ventilator control

Info

Publication number: GB2519575A
Application number: GB1318902.2A
Authority: GB
Inventors: Jonathan Wilson
Original assignee: Bentley Motors Ltd
Current assignee: Bentley Motors Ltd
Priority date: 2013-10-25
Filing date: 2013-10-25
Publication date: 2015-04-29
Also published as: GB201318902D0

Abstract

An automatic control system 10 for a vehicle seat heater 3 and/or ventilator 4 which controls operation of the heater and/or ventilator in dependence upon the difference between a set-point temperature of another control system of the vehicle, such as a HVAC system 9,10, and either an air temperature in the vehicle interior and/or air temperature external to the vehicle. The control system may also control operation of the heater and/or ventilator in dependence on solar gain of the vehicle. The seat heater may be operated when an air temperature in the vehicle interior is less than the set-point temperature by more than a threshold temperature difference. The seat ventilator may be operated when an air temperature in the vehicle interior is greater than the set-point temperature by more than a threshold temperature difference. Individual seats of the vehicle may be located in different temperature zones, and the heater and/or ventilator may only be operated when a person is detected to be sat in the seat.

Description

I

SEAT HEATER AND VENTILATOR CONTROL

Technical Field ol the Invention

The present invention relates to an automatic control system for a vehicle seat heater and/or ventilator.

Background to the Invention

AtLtomobiles are routinely fitted with sophisticated heating, ventilation and air conditioning (HYAC) systems, often known as climate control systetns, in order to improve occupant comfort. These systems are provided with automatic controls, or control settings, to facilitate their operation. Typically a user need only select a temperature and a control system will operate the HVAC system to endeavour to achieve and maintain the selected temperature.

To further increase occupant comfort it is known to provide automobile seats with electrical heaters to heat the seat, and fans to provide ventilation through the seat. In a cold climate a seat heater provides warmth to an occupant more quickly than the I-TVAC system can heat the vehicle interior, especially if the HYAC system is dependent on waste heat from the vehicle's engine. Likewise, in a hot climate, seat ventilation fans can improve the comfort of a seat in aheal soaked vehicle whilst the IIVAC system reduces the interior temperature of the vehicle.

However, provisionl of seat heating and ventilation increases the complexity of operation of the various vehicle systems aimed at improving passenger comfort mid it is not always immediately apparent to a user what is the best combination of features to deploy at a given moment to optimisc comfort.

Embodiments of the present invention seek to address this problem.

mwarv of the Invention AccoTding to the present invention there is provided an automatic control system for a vehicle seat heater and/or ventilator, wherein the control system controls operation ofthe seat heater and/or ventilator in dependence upon the difference between a. set-point temperature of anoiher control system of (lie vehicle and an air temperature in the vehicle interior and/or an air temperature external to the vehicle.

The system provides for automatic control of seat heating and/or ventilation.

enabling user comfort to be optimised without the user having to individually select the operation of seat heating or ventilation.

The other control system may be a control system of an HVAC system of the vehicle, and so the set-point temperature may be a set point temperature of the HVAC system.

The automatic control may also control operation ofthe heater and/or ventilator in dependence on solar gain of the vehicle.

The automatic control system may operate a seat heater when an air temperature in the vehicle interior is less than the set-point temperature by more than a threshold temperature difference, and may vary the output of the seat heater in dependence upon the magnitude of the difference between the air temperature in the vehicle and the set-point tempcrature. Thus, the system may provide additional warmth to a user, via a scat heater, when the temperature inside the vehicle is less than a desired temperature.

The automalic control system may operate a seat ventilator when an air temperature in the vehicle interior is greater than the set point temperature by more than a threshold temperature difference, and may varythe output ofthe ventilator in dependence upon the magnitude of the difference between the air temperature in the vehicle and the set-point temperature. Thus, the system may provide through seat ventilation, to increase user comfort, when the temperature inside the vehicle is higher than a desired Lemperalure.

The automatic control system may operate the seat ventilator when a.n air temperature in the vehicle is grealer than a predetermined threshold temperature difference below the set-point temperature and less than a predetermined threshold temperature difference above the set-point temperature and either the external temperature is greater than the set-point temperature and/or measured. solar gain is above a predetermined threshold. This provides a minimum level of through seat ventilation to increase the comfort of a user in circumstances where, although the temperature in the vehicle is at, or slightly below, the set-point temperature, the 1-IVAC system is operating to cool the vehicle interior owing to either a high outside temperature and/or a high solar gain.

The control system maybe arranged to operate the seat ventilator for a seat when the humidity of air measured by a sensor associated with the seat exceeds a threshold value, which may he a set point value determincd by a user. The sensor could be mounted on or in the seat.

The con Irol system may form part of, or he separate to, a vehicle IIVAC control system.

The invention also provides a vehicle, particularly an automobile, comprising an HYAC system arranged to operate to seek to achieve a set-point temperature within the vchielc or a zone of the vehicle and one or more seats, each scat comprising a heater and a ventilator, and a control means according to the first aspect of the invention arranged to control the or each seat heater and ventilator.

Thc vehicle may comprise two or moie seats, each scat being disposed in a different respective zone of the vehicle and the 1-IVAC system may be arranged to enable a different set-point temperature to be selected for each. zone.

Detailed Description of the Invention

In order that the invention may be more clearly understood embodiments (hereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a schematic, cut away, view of an automobile; and Figure 2 is a schematic view of a seat climate control system.

Referring to the drawings, an automobile I is fitted with four passenger seats 2, two front seats and two rear seats. P..ach seat compriscs a scat squab and a scat back. The seat squab is fined with a heating element 3. and motor driven ventilation fans 4. Ihe heating element 3 is operable to heat the surface of the seat squab on which a person may sit. The fans 4 are operable to draw air through the seat squab and discharge it under the scat. In an alternative embodiment, the fans 4 are operable to force air from under the seat through the squab and out through upholstery on the surface of the seat squab.

Each seat is also provided with a humidity sensor 12a which measures the humidity of air drawn (or forced) through the seat by the ventilation fans 4.

Although not illustrated, a heating element and/or ventilalion fan or fans could also he associated with the seat back.

Each seat is also providcd with a scatbelt 5 which! in use, is fitted into a buckle 6.

The buckle includes an electrical switch or sensor which detects when a seatbelt has been fitted to the buckle, thus signalling the presence of an occupant in the associated seat.

Each scat is provided with a user operable control 7 which enables an occupant of the seat to control the heating element 3 and ventilation fans 4 associated with that seat.

*1**he control 7 includes switches to switch on or off the heating element zmdlor ventilation fans, and to choose between at least two different output levels for both the heating element and fans. In the illustrated example both the heating element and fans may each he operated on either a high or low output modc. The control 7 also includes a switch to select an automatic operating mode for the seat heating and ventilation. The control could comprise physical controls or it could be virtual, such as provided by a graphical user interface on a screen, which may be a touch sensilive screen.

The automobile also includes a heating, ventilation and air conditioning (HVAC) system. The HVAC system comprises an air handling unit 9 with means for heating, cooling and dehumidifying air. This unit may be formed of a number of different unils and could be distributed about the vehicle. The construction and operation of such units for vehicle JIVAC systems are known to those skilled in the art, and so it will not be described in thither detail here.

The IIVAC system furLher comprises a control unit 10. The control unit 10 is operatively connected to a solar sensor 11 arranged to detect the solar load experienced by the vehicle, a humidity sensor 12 to detect the relative humidity inside th.e vehicle, each humidity sensor 12a provided in the vehicle seats and a plurality of temperature sensors 13 to detect the temperature of air outside the vehicle and/or in one or more zones within the vehicle and/or flowing from one or more vents of the HVAC system in the vehicle. The conLrol unit is also operatively cornecl.ed to one or more user operable controls 14. The control allows a user, at least, to select a desired temperature, or perceived temperature, within the vehicle. Individual controls maybe provided to enable users to select desired temperatures for different zones of the vehicle, for example upper and lower zones, driver and passenger zones, front and rear zones or four individual seat zones. The controls may again either be physical or virtual, such as represented on a screen.

The 1-IVAC control unit 10 is arranged to control the 1-IVAC air handling unit 9 to seek to achieve a desired user selected temperature within the vehicle, or a se]ected zone of the vehicle. This is a known flrnction of conventional automobile HVAC systems which is understood by those skilled in the art and so is also not described in ftirther detail.

The user operable controls 7 for the seat heating elements 3 and ventilation, fans 4 are operatively connected to the HVAC control system 10, which is in turn operatively connected to the seat heating elements 3, ventilation fans 4 and seatbelt buckle switches or sensors 6.

The 1-IVAC control system 10 is arranged to control the seat heater 3 and ventilation fans 4 of a particular seat according to a selection made on the associated user operable control 7, but will only operate either the heater or the fans whcn a scat is occupied as signalled by the seat belt buckle 6 (or alternatively by an appropriate passenger occupancy detection (POD) sensor such as a pressure sensor incorporated in the seat or an ultra sonic or other detector to detect the presence of a seat occupant). If a user selects operation of either the scat hcatcr 3 and/or ventilation fans 4 at a particular output level the HYAC control until 10 will cause the heater 3 and/or fans 4 to operate at the chosen level. If a user selects the automatic sefting, the HVAC control unitlO will cause the seat heating element 3 and/or ventilation fans 4 to operate in dependence on a difference between a set-point temperature of the HVAC system, and an actual temperature measured in the vehicle and/or an actual teinperatui-e measured cxtcrnally of the vehicle, and. may also take account of sensed solar gain.

In particular, the HVAC control system 10 will determine a desired set-point temperature for air inside the vehicle, either as a whole, for a particular zone iii the vehicle or for air delivered from a certain vent or vents within the vehicle. This temperature may he a temperature selected by a user, or it may he derived from a Lempcrature selected by a user, for example by taking account of solar gain on the vehicle. So, although a user may have selected a temperature of 20 °C, the HVAC control system may establish a lower set-point temperature to compensate for a high level of solar gain, as measured by thc solar sensor 11.

Where the actual temperature measured is less than the set-point temperature by at least certain temperature difference threshold the 1-IVAC control system will activate the seat heater 3 for the/or each seat in the region to which the temperature difference applies. The output of the seat heater 3 may be dependent upon the magnitude of the difference between the actual and set point temperatures, with a higher output being selected for a greater difference.

Where the actual temperature measured is greater than the set-point temperature by a certain temperature difference threshold the FIVAC control system will activate the seat ventilations fins for the/ar each scat in the region to which the l.ernperailLre difference applies. The output of the seat ventilation fans may be dependent upon the magnitude of the difference between the actual and set point temperatures, with a higher output being selected for a greater difference.

1 0 Where the actual temperature measured is substantially equal to the set-point temperature, buL the set point temperature is lower Lhan the temperature outside the vehicle and/or there is a solar gain above a certain threshold the JIVAC control system will activate the seat ventilations fans at their lowest output level.

So, for example, for a cold vehicle start in a cold climate when the vehicle interior 1 5 is at least 5 °C cooler than the set point temperature, and the external temperature is below the set point teniperature, the control system will auiomatically switch on the seat heating element at a high level. As the vehicle runs interior temperature will gradually increase as the FIVAC system operates. When the interior temperature is within 5 °C of the set-point temperature the control system will reduce the oulput ol the seat healing element to a low level. en the interior temperature Teaches within +/-0.5 "C of the set-point temperature the control system turns the seat heater off In a hot climate example, where the vehicle has been heat soaked and the cabin temperature is at least 5 °C greater than the set point temperature, and the set point temperature is lower than the external temperature, the control system will run the seat ventilation fans at maximum output. When the HVAC system has brought down the interior vehicle temperature to within 5 °C of the set point temperature the control system will reduce the output of the ventilation fans to a low level. The cooling fans will remain at a low level as the interior temperature reaches within +7-0.5 °C of the set-point whilst the external temperature is greater than the set point, or the measured solar gain exceeds a predetermined threshold. If the external temperature Calls below the set point arid the measured solar gain falls below the predetermined value the control system will turn off the ventilation fans.

Automatic control of seat heating and ventilation provides for increased occupant comfort. withou.t the need for the occupant to manually select an appropriate heating or ventilating ftmction. When the vehicle interior, or a selected zone thereof, is cooler than a desired set-point temperature the occupant is apt to feel cold. The seat healer then operates to counteract this. When the vehicle interior, or a zone thereof, hotter than a desired set-point temperature the occupant is apt to feel hot. The seat ventilation Nns then operate to counteract this.

The conirol system may also cause the seat ventilation fans to operate when the humidity (which maybe measured as relative humidity) of air inside the vehicle and/or measured by an individual seat humidity sensor 12a. exceeds a predetermined threshold, which may be a set point value, and could he selected by a user. In this scenario, the seat ventilation fans may operate even if they would not operate on the basis of any temperature differential. Or, where the seat ventilation fans are already operating at a given output lcvcl, the output level may increase in the event that measured humidity exceeds a threshold value. Where the seat ventilation fans are conu'olled in dependence on humidity measured in a particular seaL, then only the fans associated with the seat where humidity is measured will be controlled in dependence on the humidity measured in that seat.

A particular setting or combination or settings for the heating and/or ventilation of a seat may be stored by the control system in association with an identifier for a particular user, and the sysieni may automatically adopt the stored sellings whcn the user's presence is detected in the vehicle. This could, for example by the user selecting a stored value, or by using a particular key, transmitter or transponder to access the vehicle.

The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as. defined in the appended claims.

Claims

CLAIMS1. An automatic control system for a vehicle seat heater and/or ventilator, wherein the control system controls operation of the seat heater and/or ventilator in dependence upon the difference between a set-point temperature of a control system of the vehicle and an air temperature in the vehicle interior and/or an air temperature external to the vehicle.
2. An automatic control system as claimed in claim 1 wherein the set-point temperature is a set point temperature of an HVAC system of the vehicle.
3. An automatic control system as claimed in either claim 1 or 2 whereinthe system controls operation of the healer anchor ventilator in dependence on solar gain of the vehicle.
4. An automatic control system as claimed in any preceding claim arranged to operate a seat heater when an air temperature in the vehicle interior is less than the set-point temperature by more than a threshold temperature difference.
5. An automatic control system as claimed in claim 4 wherein the control system varies the output of the seat heater in dependence upon the magnitude of the difference between the air temperature in the vehicle and the set-point temperature.
6. An automatic control system as claimed in any preceding claim arranged to operate a seat ventilator when an air temperature in the vehicle interior is greater than the set point temperature by more than a threshold temperature difference.
7. An automatic control system as claimed in claim 6 wherein the control system varies the output of the ventilator in dependence upon the magnitude of the difference between the air temperature in the vehicle and the set-point temperature.
8. An automatic control system as claimed in any preceding claim arranged to operate the seat ventilator when an air temperature in the vehicle is greater than a predetermined threshold temperature difference below the set-point temperalure and less than a predetermined threshold temperature difference above the set-point temperature and either the external temperature is greater than the set-point temperature and/or measured solar gain is above a predetermined threshold.
9. An automatic control system as claimed in any preceding claim arranged to operate the seat ventilator for a seat when the humidity of air measured by a sensor associated with the seat exceeds a threshold value.
10. A vehicle comprising an HYAC system arranged to operate to seek to achieve a set-point temperature within the vehicle or a zone of the vehicle and one or more seats, each comprising a heater and/or a. ventilal.oi-, and a control means as claimed in any preceding claim arranged to control the or each seat heater and ventilator.
11. A vehicle as claimed in claim 10 comprising Iwo or more seats, each seat being disposed in a different respective zone of the vehicle and wherein the HVAC system is arranged to enable a different set-point temperature to be selected for each zone.
12. A vehicle as claimed in either claim 10 or 11 comprising a respective associated rith the or each seat, the detector being arranged to determine if the associated scat is occupied, and whcrcin the control system will only operate the seat heater and/or ventilator for that seat if the detector detects that the seat is occupied.
13. An automatic confrol system substantially as herein described with reference to the accompanying drawings.
14. A vehicle comprising an HVAC system, one or more seats provided with a heater and/or a ventilator and a control system for the heater and venl.ilator substantially as herein described with reference to the accompanying drawings.