GB2344647A

GB2344647A - A vehicle climate control arrangement

Info

Publication number: GB2344647A
Application number: GB9827209A
Authority: GB
Inventors: Neil Beloe
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1998-12-11
Filing date: 1998-12-11
Publication date: 2000-06-14
Also published as: GB9827209D0

Abstract

A vehicle climate control arrangement is provided whereby infra-red sensors (6, 7, 8) are arranged to have respective fields of view (9, 10, 11) such that the body temperature of a vehicle occupant (3) can be determined. Thus, the infra-red sensors (6, 7, 8) provide a control signal for climate variation means, such as a heater, fan blower and/or air conditioning system, may be sympathetically variably operated in order to adjust the environmental temperature about that occupant (3).

Description

A VEHICLE CLIMATE CONTROL ARRANGEMENT The present invention relates to a vehicle climate control arrangement.

It has become quite commonplace to include within a motor vehicle a relatively sophisticated climate control system such that the vehicle cabin, in terms of temperature and ventilation, can be more pleasant to an occupant. These climate control systems essentially vary the climate within a vehicle cabin dependent upon occupant determined variables and a control mechanism configured to achieve those occupant determined variables. An objective of an automatic control for a vehicle climate control arrangement is to ensue that once set, the occupant does not need to constantly adjust controls particularly during periods of active driving.

Typically, a vehicle climate control arrangement will know the capabilities of its climate variation means such as heaters, air conditioning, fans and vent orientations along with the occupants desired cabin climate and so can determine a strategy to achieve that desired cabin climate. However, it will be understood that the occupants current skin temperature may vary dependent upon the level of occupant activity and external factors such as solar exposure. In such circumstances, the climate control arrangement should adapt to the current occupant requirements to either dissipate heat or absorb heat rather than an idealised figure for temperature utilised to determine desired cabin climate acquisition.

It is an object of the present invention to provide a vehicle climate control arrangement which substantially achieves the above-mentioned sophistication.

In accordance with the present invention there is provided a vehicle climate control arrangement wherein the arrangement includes climate variation means, infra-red sensor means and a controller coupled to both the climate variation means and the infra-red sensor means,, the infra-red sensor means in use being specifically receptive of and orientated to an occupant of a vehicle to provide a control signal to the controller indicative of that occupants surface temperature, the controller in response to that control signal being arranged to sympathetically vary operation of the climate variation means to adjust environmental temperature about that occupant. Typically, the arrangement will also include various other means of compensation for other climate determining factors.

Typically, the infra-red sensor means will be arranged to view specific parts or zones of an occupant. Furthermore, several infra-red sensors could be included in the infra-red sensor means with each respective sensors arranged in use to be specifically receptive of and orientate to a particular part or zone of the occupant or occupants. With such a specifically receptive and orientated infra-red sensors to parts or zones of the occupant, the climate variation means may be specifically adjusted to be sympathetically varied for each respective part or zone of the occupant or occupants.

The climate variation means may include a heater and/or blower and/or air conditioning system.

The infra-red sensing means may be arranged to differentiate between background infra-red response and that specific of the occupant of the vehicle.

The vehicle climate control arrangement could be arranged to have respective infra-red sensors for several occupants within the vehicle such that sympathetic variation of the operation of the climate control variation means for each respective occupant to adjust environmental temperature about that occupant can be achieved.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, depicting in symbolic side elevation a vehicle climate control arrangement.

As indicated above, it is well know to provide within a motor vehicle a climate control arrangement in which a climate variation group of devices such as heaters, fans and air conditioning apparatus is provided to vary the vehicles cabin climate under the control of a controller. The controller compares the vehicle occupant's desired climate with that current within the vehicle cabin in order to develop a strategy to alter the vehicle cabin therebetween. As indicated previously, it is desirable that the controller and the vehicle climate control arrangement should be automatic to diminish unnecessary distraction to a vehicle occupant and in particular the vehicle's driver. It will also be understood that interference from the vehicle occupant may also alter significantly the appropriateness of the particular strategy determined by the controller to achieve the desired vehicle cabin climate as efficiently and effectively as possible.

Of particular concern with regard to the present invention is a vehicle occupant's perceived comfort. Normally, a vehicle occupant's body temperature is a good indicator of that occupant's comfort within a vehicle cabin with reference to the desired climate indicated to the controller by that occupant. It is the inherent variations in the vehicle occupant's body temperature due to constantly changing factors within the vehicle which necessitate that occupant in making manual adjustments in the vehicle climate control arrangements. The vehicle occupant's body temperature may vary due to the level of activity of that occupant, ie. between straight line highway driving and constant cornering, etc, typical of secondary road travel along with changing solar radiation exposure, wind-chill and other external factors.

In order to accommodate these changes in the vehicle occupant's body temperature, the present invention incorporates infra-red sensors which provide a control signal to the vehicle climate control arrangement controller in order to provide a sympathetic variation in the operation of the climate variation means comprising the heater and/or blower and/or air conditioning system to adjust the environmental temperature about that occupant. Clearly, the occupant can either be too cold or too hot relative to the desired climate within the vehicle cabin. In such circumstances, the controller, in response to the control signal provided by the infra-red sensor will sympathetically vary the operation of the climate variation means in order to adjust the environmental temperature about the occupant more consistently with the desired climate and therefore occupant body temperature.

In the drawing a vehicle 1 includes a seat 2 for an occupant 3 such that the occupant 3 is held within a cabin 4 of the vehicle 1. This cabin 4 includes a vehicle dashboard 5 from which climate variation devices such as those previously described precipitate alteration of the cabin 4 climate. However, it will also be understood that climate variation devices could also be incorporated in other services of the cabin 4 in order to provide a more even distribution of climate variation within that cabin 4. These climate variation devices are well known to those skilled in the art and will therefore not be further described other than as necessary.

In accordance with the present invention, the climate variation means comprising the climate variation heaters, blowers and other devices described previously is controlled by a controller in response to a control signal provided by at least one infra-red sensor. In the embodiment depicted in the drawing, three infra-red sensors 6,7,8 are provided such that each sensor 6,7,8 is arranged to be specifically receptive of and orientated to a particular part or zone of the occupant 3 in order to provide a control signal indicative of the temperature of that particular part or zone of the occupant 3. It will be understood that alternatively a single infra-red sensor could be provided for the whole or a substantial representative part of the occupant 3 and so that this infra-red sensor provides a single control signal in accordance with the present invention indicative of the occupant's 3 body temperature. Each infra-red sensor 6,7,8 is arranged through appropriate aperture guiding only to be receptive of and orientated towards a particular part or zone of the occupant 3. Such orientation of the respective sensors 6,7,8 could be achieved through providing a funnel-type aperture guide or other means of focus such as lensing for each sensor 6,7,8. In such circumstances, respective sensors 6,7,8 will each have field of view or radiation reception cones 9,10,11 within which infra-red radiation from the occupant 3 can be determined by its respective sensor 6,7,8.

Infra-red sensors are available from suppliers such as Quayhead Industries Ltd, England and Exergen Inc of the USA which have sufficient accuracy to provide differential control signals dependent upon variations in occupant 3 temperature. These infra-red sensors are typically a thermopile which provide variations in electrical current or voltage dependent upon the level of infra-red radiation variation received. In accordance with the present invention, these infra-red sensors must be sufficiently sensitive to be able to differentiate within the relatively narrow temperature band, ie. a few degrees Celsius, about normal human body temperature in order to provide an appropriate control signal for the controller and so resultant sympathetic operation of the climate variation means described previously.

As indicated above, it is preferred that different parts or zones of the occupant 3 are arranged to be specifically receptive of and orientated to a respective sensor 6,7,8. In such circumstances, the climate variation means as described previously can be differentiated in terms of the air flow rate and air temperature presented in that air flow to the occupant 3 in order to be reciprocal of the current temperature of a particular part of zone of the occupant 3. Typically, as illustrated, one infra-red sensor 6 will be directed towards the head and upper torso of the occupant 3, a second infra-red sensor 7 will be directed to a midriff area of the occupant 3, whilst a third infra-red sensor 8 will be directed towards a leg area of the occupant 3.

Each sensor 6,7,8 will received infra-red radiation from the occupant 3 and possibly any other surfaces within its field of view 9,10,11. Thus, each sensor 6,7, 8 can be arranged to provide a differential between a background thermal level due to the environment of the cabin 4 with that infra-red radiation due to the occupant 3. This differential level may be achieved through extrapolation of infrared levels prior to occupant 3 entering the vehicle 1 or measurement by means of air temperature sensing, etc.

It will be understood by those skilled in the art that respective infra-red sensor means can be provided for each seat 2 within a vehicle 1 in which an occupant 3 can be located. Thus, within the scope of the present invention, there is a vehicle climate control arrangement where respective infra-red sensor means for each seat position is utilised to provide a control signal to the controller whereby the climate variation means, ie. blowers, heater and air-conditioning system can be varied in accordance with respective occupant's temperature in each seat of the vehicle 1.

The present invention utilises the infra-red radiation response from the occupant 3 in order to provide an indication of that occupant's temperature and so utilise this response to improve occupant comfort within the vehicle 1. Thus, the arrangement utilises infra-red radiation from the surface of the occupant 3 in order to adjust cabin air temperature to compensate for loss or gain of heat from the occupant. In such circumstances, it will be appreciated that the level of clothing worn by the occupant 3 can vary but generally the surface temperature of such clothing is still a clear indication of the occupant's 3 requirement for warming or cooling. However, it will be appreciated that the occupant's head 12 is normally exposed and so provides the most reliable indication of occupant 3 body temperature for climate control purposes. However, to ensure capture within its respective range of view 9 it will be appreciated by those skilled in the arts it is more important to align the sensors 6 with the occupants head 12 than with regard to the other sensors 7,8. This alignment can be achieved through mounting the sensor 6 in the rear view mirror which must be adjusted by the occupant 3 for operation and so will orientate the sensor 6 towards their head.

Alternatively, the sensor 6 could be provided with a relatively wide range of view 9 to accommodate occupant 3 height and size ranges.

It will be appreciated that generally the narrower the range of view 9,10,11 used for each respective sensor 6,7,8, the smaller the infra-red radiation zone determined by that sensor 6,7,8. Thus, the accuracy of the sensor 6,7,8 can be varied either by increasing the field of view 9,10,11 in order to provide a more statistically spread infra-red radiation response or by narrowing the range of view 9,10,11 providing a more accurate determination for the radiating area but potentially less statistically accurate of its respective part or zone of the occupant 3 for temperature determination purposes.

By use of infra-red sensors 6,7,8 in the present climate control arrangement, it will be appreciated that actual occupant 3 position within the vehicle 1 is made irrelevant with regard to the accuracy of temperature determination for that occupant 3. In effect, there will only be a relatively marginal variation in the absolute area of the occupant 3 coinciding with the field of view 9,10,11 of each respective sensor 6,7,8 and this will normally be within expected accuracy levels for the climate control arrangement. Furthermore, in addition to providing specific temperature determinations for respective zones or parts of the occupant 3, the respective sensors 6,7,8 could provide control signals which are consolidated into a principal control signal utilised by the controller to vary operation of the climate variation means collective rather than specifically for respective parts or zones of the occupant 3. Thus, the climate control arrangement could be configured to allow collective sensors 6,7,8 control signal determination initially and then subsequent individual control signal determination for respective parts or zones of the occupant 3 after the cabin 4 has substantially approached the cabin climate desired by the occupant 3.

As indicated above, it will be appreciated that the vehicle 1, during a journey will experience differing external environmental factors such as wind-chill and weather conditions along with a degree of exposure to sunlight. In such circumstances, the cabin 4 will also be exposed to varied conditions which may alter cabin climate precipitating as indicated previously, occupant 3 manual adjustment. It will be appreciated that in accordance with the present invention, inclusion of infra-red sensors 6,7,8 provides a control operand which upon an ongoing basis provides a feedback response of the occupant 3 body temperature for control of the climate variation means in order to reduce the effects of these external environmental factors to the vehicle 1. It will also be understood that the occupant 3 can, depending upon their style of driving and the type of journey undertaken, generate varying degrees of body heat due to physical effort. The present vehicle climate control arrangement allows such variations in occupant 3 body temperature to be sympathetically reflected in the operation of the climate control arrangement without specific manual alteration of the climate control.

Typically, the vehicle 1 will include a windscreen 14 such that the sensor 6 may be located above that windscreen 14 whilst the other infra-red sensors 6,7 for respective parts of the occupant 3 may be angled within the dashboard 5 in order to be specifically receptive of and orientated to that occupant 3. Clearly, the sensors 6,7,8 must be directed such that their fields of view 9,10,11 are substantially inward of the vehicle 1 otherwise extraneous infra-red responses will be significantly sensed.

In addition to the sensors 6,7,8 directed towards the occupant 3, it will be appreciated that a further infra-red sensor could be provided within the cabin 4 of the vehicle 1 in order to provide the background infra-red radiation level. This, as indicated previously, could be used to provide a differential response more indicative of occupant 3 temperature or utilised by the controller of the vehicle climate control arrangement in order to determine the degree of heat energy loss or gain by the occupant 3 from the environment thereabout in the vehicle 4. It will be appreciated that it is the air about the occupant 3 which significantly determines that occupants comfort. Thus, the climate variation means comprising a heater and/or blower and/or air-conditioning system must principally vary the air about the occupant 3 in order to provide the necessary occupant 3 comfort desired. It is by the nature of the climate variation means that the air in terms of its mass flow, turbulence and temperature will be varied in accordance with the present invention about the occupant 3. As the air turbulence about the occupant 3 will not significantly vary the sensor 6,7,8 response to radiated infra-red from the occupant 3, it will be appreciated that there will not be not detrimental effects upon the accuracy of the present climate control arrangement.

Claims

CLAIMS 1. A vehicle climate control arrangement, wherein the arrangement includes climate variation means, infra-red sensor means and a controller coupled to both the climate variation means and the infra-red sensor means, the infra red sensor means in use being specifically receptive of and orientated to an occupant of a vehicle to provide a control signal to the controller indicative of that occupant's temperature, the controller in response to that control signal being arranged to sympathetically vary operation of the climate variation means to adjust environmental temperature about the occupant.
2. An arrangement as claimed in Claim 1, wherein the infra-red sensor means is arranged to be specifically receptive of and orientated to a specific part or zone of the occupant.
3. An arrangement as claimed in Claim 2, wherein the controller is arranged to sympathetically vary operation of the climate variation means for that specific part or zone of the occupant to which the infra-red sensor means is specifically receptive and orientated.
4. An arrangement as claimed in any preceding claim, wherein the climate variation means includes a heater and/or a blower and/or an air conditioning system.
5. An arrangement as claimed in any preceding claim, wherein the infra-red sensor means is arranged to determine background infra-red radiation away from the occupant in order that a differential between that background infra red radiation and infra-red radiation from the occupant is determined in order to provide the control signal to the controller.
6. An arrangement as claimed in any preceding claim, wherein the infra-red sensor means comprises respective infra-red sensors directed to respective seats of a motor vehicle in which an occupant can be seated and thereby respective infra-red sensors of the infra-red sensor means can specifically be receptive of and orientated to each occupant to provide a respective control signal to the controller.
7. An arrangement as claimed in Claim 6, wherein the respective control signals from each respective infra-red sensor are consolidated to provide a principal control signal for the controller which thereby sympathetically varies operation of the climate variation means to adjust the environmental temperature about each occupant.
8. An arrangement as claimed in Claim 6, wherein each control signal from a respective infra-red sensor of the infra-red sensor means is used by the controller to respectively sympathetically vary operation of the climate control means in order to adjust environmental temperature about each respective occupant dependent upon the control signal provided by its respective infra red sensor.
9. A vehicle climate control arrangement, substantially as hereinbefore described with reference to the accompanying drawing.
10. A motor vehicle including a vehicle climate control arrangement as claimed in any preceding claim.