GB2340221A

GB2340221A - Demisting a vehicle

Info

Publication number: GB2340221A
Application number: GB9916523A
Authority: GB
Inventors: Keith Stafford Farrell; Kevin Trevor Talbot
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1998-07-29
Filing date: 1999-07-15
Publication date: 2000-02-16
Anticipated expiration: 2019-07-15
Also published as: GB2340221B; GB9916523D0; GB9816407D0

Description

2340221 A Vehicle This invention relates to vehicles and in particular to

a vehicle which includes a heating and ventilating system.

It is well known to provide a vehicle with means to heat or cool the air entering an interior or passenger compartment of the vehicle. Such prior art heating and ventilating systems normally include driver operable inputs to varv the level of the flow and/or temperature of the air entering the passenger compartment and a further separate driver operable control to alter the distribution pattern of the air flow between different ventilation outlets located within the passenger compartment. It is usual to have demister vents in the proximity of the windscreen to perform a de misting/de frosting action, vents directed towards the feet of the occupants and vents directed towards the faces of the occupants.

It is further known to provide an air conditioning system for a vehicle in which the temperature of the passenger compartment is thermostatically maintained at a predetermined temperature set by the driver.

It has been a disadvantage with some such prior art svstems that the amount of cooling or heating supplied to the passenger compartment is substantially independent of the number of occupants in the vehicle and

2- this has been known to result in a considerable amount of energy being wasted cooling or heating unoccupied areas of the passenger compartment, This could be a particular problem if the vehicle is electrically powered, as the energy for the heating and cooling of the air may then be derived from the same energy source as that used to provide propulsion for the vehicle. 'Wasting energy in heating, cooling or demisting the passenger compartment (or parts thereof) unnecessarily would, therefore, reduce the effective range which such a vehicle could travel before it required its energy source replenishing.

One attempt to improve the efficiency and utility of heating and ventilating systems for vehicles is disclosed in EP 0419722. This heating and ventilating system is provided with seat occupation sensors and the quantity and distribution characteristics of the air supply for the passenger compartment is automatically regulated to meet the individual expectations for comfort of the passengers and so that account can be taken of unoccupied seats.

It is an object of this invention to provide an improved vehicle.

According to the invention there is provided a vehicle comprising a body defining a passenger compartment, an occupancy sensing means arranged in use to provide to a control means an occupancy signal indicative of the level and/or distribution of occupation by living beings of said passenger compartment and a heating and ventilating means under the control of the control means, wherein the control means is arranged in use to control the heating and ventilating means so as to provide for at least one window of the passenger compartment a level and/or distribution pattern of demisting which is derived by the control means from the occupancy signal to be appropriate for the current level and/or distribution of occupation. The term "demisting" should be understood by the reader to encompass also 10 defrosting as appropriate in cases of low outside temperatures.

The level and/or distribution pattern of demisting provided in response to the occupancy signal may be regulated at least in part by controlling the output of a flow control means which is arranged in use to control the flow of air from one or more ducts.

The flow control means may comprise an air propelling means and the regulation may comprise control over the volume of air provided by said propelling means for demisting.

The flow control means may comprise at least one control flap substantially in line with a said duct, or at least influencing the flow of air therethrough, and the regulation may comprise control over the volume or distribution pattern of air provided by said duct for demisting.

The control means may be arranged to control the temperature of the demisting air applied to said window in such a manner that account is 5 taken of the current level and/or distribution of occupation.

The control means may be arranged to bias the level and/or distribution pattern of demisting across the face of said window in such a manner that the level and/or distribution pattern of demisting applied takes account of the position in the passenger compartment of a living being or beings.

The control means may be arranged to control the level and/or distribution pattern of demisting applied to a side window of the passenger compartment in such a manner that the level and/or distribution pattern of demisting applied thereto takes account of whether a said living being is in the -vicinity of said side window.

The vehicle may further comprise a manual input means arranged to influence the output of the heating and ventilating means and the control means may be arranged to over-ride the manual input means if it is necessary to do so in order to provide an appropriate level and/or distribution pattern of demisting, which level and/or distribution pattern the control means has deemed necessary as a result of considering the level and/or distribution of occupancy.

The invention will now be described by way of example only and with reference to the accompanying drawing, in which:

Figure 1 is a schematic diagram of a vehicle according to the invention.

Referring to the figure, a vehicle 10 has a heating and ventilating unit 11 arranged to supply air to a passenger compartment of the vehicle via a number of ducts 15a, 16a, 17a, 18a, 21a, 23a, 25a, 27a and vents 15, 16, 18, 21, 23, 25, 27.

Each of the vents 15, 16, 18, 21, 23, 25, 27 has an electrically operated valve associated with it to control/regulate the volume and distribution pattern of the air permitted to flow from the vent. The valves are connected by means of leads 15b, 16b, 18b, 21b, 23b, 25b, 27b to an electronic power controller 14.

The electronic power controller 14 is connected to a heating and ventilating electronic control unit 13 which is used to controPregulate the level of temperature, flow and distribution pattern of the air exiting the heating and ventilating unit 11. The heating and ventilating unit 11 includes means to heat or cool the air passing therethrough, means to dixect the air into one or more of the ducts 15a, 16a, 17a, 18a, 21a, 23a, 25a, 27a and a propelling means in the form of a blower or fan unit to propel/urge air to flow through one or more of the ducts 15a, 16a, 17a, 18a, 21a, 23a, 25a, 5 27a.

An isolation valve 17 is connected to the power controller 14 by a lead 17b and can be used to cut off the flow of air along the duct 17a leading to the rear passenger compartment of the vehicle.

The electronic control unit 13 is arranged to receive and continuously monitor both heating and ventilating demand signals from a manual input means 12 and occupancy signals from an occupancy sensing means. The occupancy sensing means is in the form of a number of occupancy sensors 22, 26 which are associated with the front and rear passenger seats 20 of the vehicle 10, as outlined in greater detail below.

In this embodiment, no occupancil sensors are associated with the driver's seat 19 as there is usually a driver in position when the vehicle 10 is in use. It would be possible, however, to provide an occupancy sensor for the driver's seat if it was felt to be useful, e.g. in case the driver leaves the vehicle 10 but wishes to leave the heating and ventilating system running for the comfort of living beings, such as passengers or pets, who stay in the vehicle 10.

One set of occupancy sensors 22 comprise weight sensors included in the seats 20. A second set of occupancy sensors 26 monitor whether a passenger seat 20 is occupied by checking whether a seat belt 24 associated with each seat 20 is in use. Other forms of occupancy sensing could be used in addition or instead of weight sensing 22 or seat belt sensing 26, e.g. CCD techniques or infrared transducers of the tv ILr I pe known for ai -bag deployme nt/de activation, and this could take account of a user who may not be properly detected by the weight sensors 22 (e.g. a baby seat or a pet) or a user who is not wearing a seat belt 24.

The electronic control unit 13 continually monitors the inputs being received from both sets of sensors 22, 26 to establish whether a seat 20 is - occupied. The occupancy sensors 22, 26 send to the electronic control unit 13 an occupancy signal which is indicative of the level of occupation by living beings of the passenger compartment. The occupancy signal is sent to the electronic control unit 13 via one of a number of occupancy sensor input leads 28. Operation of the heating and ventilating system in response to the occupancy signal is outlined below.

As stated above, the electronic control unit 13 continuously monitors the signals received from the manual input means 12 and from the occupancy sensing means 22, 26.

The manual input means 12 continuously supplies a demand signal to the electronic control unit 13 indicating desired level of temperature/volume of flow and the desired flow path/distribution pattern of de misting/defro sting air.

For example, if the driver demands demisting then the electronic control unit 13 will, via the power controller 14, close all of the valves 10associated with the vents 15,, 16, 18, 21., 25, 27 but open the valve associated with the demister vent 23 to maximum.

In addition, the electronic control unit 13 will send a signal to the power controller 14 so as to cause it to provide hot or cold air, as appropriate, to the demister vent 23 and will energise the air propelling means (e.g. blower or fan).

If the vehicle 10 is sensed by the occupancy sensing means 22, 26 to be unoccupied apart from the driver, then after a short period of time the speed of the blower will be automatically reduced to a low speed thereby reducing the flow of air from the demister vent 23.

If the electronic control unit senses that the vehicle 10 is fully occupied, however, then the blower speed will not be reduced by such a large amount because of the greater tendency for condensation to form with more occupants in the vehicle 10.

In this manner, the electronic control unit 13 is programmed to apply to at least one window of the passenger compartment, e.g. the windscreen, a level of temperature/volume and/or distribution pattern of de mistin g/de frosting which is appropriate to the sensed level of occupancy. This control over demisting is also used to control side window demisting/defrosting via side window demisting vents (not shown separately) and can thus automatically demist/defrost a passenger side window using a level and/or distribution pattern of demisting which is dictated by whether or not a seat associated with that window is occupied.

The electronic control unit 13 could also be programmed to over-ride the manual input means 12, under certain circumstances, so to concentrate on demisting/defrosting the widscreen and or the door mirror area of the side windows. For example, if the passenger compartment is fully occupied and/or a humidity, ambient temperature and/or rain sensing means (none shown) indicates to the electronic control unit 13 that it is likely the windscreen needs demisting/defrosting, then the electronic control unit 13 could apply a predetermined level and/or distribution pattern of - lo- de misting/de frosting to the windscreen? perhaps in accordance with a predetermined or adaptive time-out, before implementing a user-comfort inspired and requested manual input.

If the driver input indicates that a mixture of air flow to both face vents 25? 27 and to the foot vents 15, 161, 18, 21 is required then the electronic control unit 13 firstly determines the occupancy of the vehicle 10 and then sends a control signal via the power controller 14 to the valves associated with those vents to place them in a preferred state. For example, if no living beings are sensed to be present on the rear seat 20 of the vehicle 10, the isolation valve 17 is closed thereby directing all of the air flow to the front of the vehicle 10. Whereas, if only one of the rear seats 20 is sensed to be occupied, the isolation valve 17 is left open but the valve associated with the vent 18 or 21 nearest to the unoccupied seat is closed.

If the vehicle is sensed to be unoccupied, apart from the driver, then all of the valves are closed except those which supply air to the driver's face air vent 15, to his foot air vent 25 and (if selected) to the windscreen demister vent 23.

In the case of the windscreen demister vent 23, the level and/or distribution pattern of de misting/defro sting applied between the passenger side of the windscreen and the driver's side would be automatically biased so as to take account of the fact that there were no passengers. Even if there were passengers, the level and/or distribution of de misting/de frosting could be biased so as to clear the driver's side first.

As previously discussed with respect to demisting/defrosting of the 5 vehicle 10, the blower is also adjusted according to the number of occupants, i.e. being set at a higher throughput when the vehicle occupancy is sensed to be higher. If the vehicle 10 is sensed to be full, however, then the temperature of the air provided from the heating and ventilating unit 11 may need to be lower than if the vehicle 10 is sensed to be empty apart from the driver. This would be done automatically so as to compensate for the heating effect derived from the living beings located within the passenger compartment of the vehicle 10. When the heating and ventilating unit 11 is set to provide hot air, therefore, the temperature of that air may need to be lower if the vehicle 10 is full than it would be if the vehicle 10 were sensed to be empty apart from the driver and, conversely, if cold air is being supplied by the heating and ventilating unit 11, the temperature of this air may need to be lower if the vehicle 10 is sensed to be fully occupied than it would be if the vehicle 10 were sensed to be unoccupied apart from the driver.

The electronic control unit 13 is therefore operable to supply air as demanded by the driver to the various vents 15, 16, 18, 21, 23, 25, 27 within the vehicle 10 in a quantity and at a temperature that corresponds to the most economical way of achieving the climatic state and level and/or distribution pattern of de misting/de frosting required and/or demanded by the driver.

It will be appreciated that, if independent temperature controls are provided to the passengers of the vehicle, then these controls can be automatically ignored by the electronic control unit 13 if the corresponding seat 20 is sensed to be unoccupied.

It will be appreciated by the man skilled in the art that the valves associated with the outlet ducts can be located in the ducts themselves as described above or could be incorporated as part of the heating and ventilating unit 11. It will be further appreciated that the electronic control unit 13 could also be supplied with signals from ambient climate sensors such as humidity and external temperature sensors which could be used to modifN- the wav in which the electronic control unit 13 controls the heating and ventilating unit 11. In high humidity conditions, for example, the speed of the blower fan may be set higher than it would be for the same number of occupants if the humidity is sensed to be low.

Claims

- 13CLAIMS

1. A vehicle comprising a body defining a passenger compartment, an occupancy sensing means arranged in use to provide to a control means an occupancy signal indicative of the level and/or distribution of occupation by living beings of said passenger compartment and a heating and ventilating means under the control of the control means, wherein the control means is arranged in use to control the heating and ventilating means so as to provide for at least one window of the passenger compartment a level and/or distribution pattern of demisting which is derived by the control means from the occupancy signal to be appropriate for the current level and/or distribution of occupation.

2. A vehicle according to Claim 1, wherein the level and/or distribution pattern of demisting provided in response to the occupancy signal is regulated at least in part by controlling the output of a flow control means which is arranged in use to control the flow of air from one or more ducts.

3. A vehicle according to Claim 2, the flow control means comprising an air propelling means and the regulation comprising control over the volume of air provided by said propelling means for demisting.

4. A vehicle according to Claim 2, the flow control means comprising at least one control flap substantially in line with a said duct, or at least influencing the flow of air therethrough, and the regulation comprising control over the volume or distribution pattern of air provided by said duct for demisting.

5. A vehicle according to any preceding claim, wherein the control means is arranged to control the temperature of the demisting air applied to said window in such a manner that account is taken of the current level and/or distribution of occupation.

6. A vehicle according to any preceding claim, wherein the control means is arranged to bias the level of demisting across the face of said window in such a manner that the level and/or distribution pattern of demisting applied takes account of the position in the passenger compartment of a living being or beings.

7. A vehicle according to any preceding claim, wherein the control means is arranged to control the level and/or distribution pattern of demisting applied to a side window of the passenger compartment in such a manner that the level and/or distribution pattern of demisting applied thereto takes account of whether a said living being is in the vicinity of said side window.

8. A vehicle according to any preceding claim, further comprising a manual input means arranged to influence the output of the heating and ventilating means.

9. A vehicle according to Claim 8, wherein the control means is arranged to over-ride the manual input means if it is necessary to do so in order to provide an appropriate level and/or distribution pattern of demisting, which level and/or distribution pattern the control means has deemed necessary as a result of considering the level and/or I distribution of occupancy.

10. A vehicle substantially as described herein with reference to the accompanying drawing.