DE102016219203B4 - Method for air conditioning a vehicle seat and vehicle with such an air-conditioned vehicle seat - Google Patents

Abstract

Method for air conditioning a vehicle seat (2) occupied by a vehicle occupant (3), which in turn has a seat ventilation device (4) and a seat heating device (7), wherein, using an electronic control unit - ECU - (10), the seat ventilation device (4) and the seat heating device (7) are controlled and regulated as a function of an absolute contact humidity of a surface (5) of the vehicle seat (2) determined by means of at least one humidity sensor (8) and a contact temperature of the vehicle occupant (3) determined by means of at least one temperature sensor (9), and wherein the contact temperature of the vehicle occupant (3) is determined by means of at least one temperature sensor (9) of the vehicle seat (2), and the control and regulation are carried out in such a way that, with minimized seat heating power, the contact temperature in the vehicle seat (2) for the relevant vehicle occupant (3) is set to a value above a predetermined control reference value of the temperature and the absolute contact humidity is set to a value below a predetermined The system is characterized in that the seat ventilation device (4) and the seat heating device (7) are regulated and controlled in additional dependence on a heat flow between the vehicle occupant (3) and the vehicle seat (2) detected by means of at least one heat flow sensor (9').

Description

The invention relates to a method for air conditioning a vehicle seat occupied by a vehicle occupant according to the preamble of patent claim 1 of the invention. According to the preamble of patent claim 10 of the invention, the same further relates to a vehicle, in particular a motor vehicle, with such an air-conditioned vehicle seat.

It is known that a vehicle occupant's overall thermal comfort perception is significantly influenced by the contact area of the vehicle seat. On longer journeys, the heat and moisture emitted by the vehicle occupant builds up in the vehicle seat over the course of a journey and can lead to discomfort. Furthermore, it is known that the average skin temperature of a person in the thermal comfort zone, or the zone where it is perceived as too warm, is approximately 34°C. In the zone where it is perceived as too warm, the human body attempts to achieve increased heat dissipation through evaporation by releasing moisture (sweat). In the zone where it is perceived as cool or too cold, the skin temperature drops. There, the body attempts to achieve reduced heat dissipation by reducing blood flow (contraction of the blood vessels in the skin). However, with the help of a so-called seat ventilation system, which has at least one preferably electrically operated seat fan, the thermal comfort on the back and/or buttocks of the vehicle occupant can be quickly restored by drying. Furthermore, it is known to measure the actual temperature of the vehicle occupant by means of temperature sensors and to use the resulting measured values to control and regulate a seat temperature device, in particular in the form of an electrically operated heating device. Essentially, a contact temperature on the vehicle occupant, in particular the skin temperature of the same, is measured. The seat temperature device is controlled depending on the currently measured actual temperature, i.e., more or less heating or cooling is provided for the respective vehicle occupant, preferably by zonal air conditioning, if a deviation or a trend of a deviation from a setpoint stored or preset in an electronic control unit (ECU) is recorded. This relationship is found in the DE 10 2014 206 613 A1 Consideration which deals with a method for air conditioning a vehicle seat occupied by a vehicle occupant, using a seat ventilation device and a seat temperature control device. Essentially, it is proposed here, firstly, to determine a humidity value representative of the humidity of a surface of the vehicle seat by means of a humidity sensor arrangement and to control the seat ventilation device and the seat temperature control device as a function of the determined humidity value. Secondly, to control the seat ventilation device and the seat temperature control device in addition as a function of a skin temperature value representative of the skin temperature of the face and/or hand area of the vehicle occupant, which is detected by means of a temperature sensor arrangement, in order to thus achieve a thermal comfort state for the vehicle occupant in question.

From the DE 197 26 810 C1 A so-called climate-controlled seat is known, comprising a moisture-absorbing layer arranged between a moisture-permeable cover and upholstery, and an electric heating device with a control device for drying the seat. The heating device is arranged as a seat heater between the cover and the upholstery. At least one sensor element of a sensor device is arranged in the moisture-absorbing layer or in the cover, which sensor element transmits moisture and/or temperature signals to the control device. Furthermore, it is provided that the seat heater can be automatically switched on and off by means of the control device depending on signals from the sensor device when a predetermined or predeterminable humidity level is exceeded. Furthermore, a ventilation device is provided, which is arranged near the seat surface facing the user and can be switched on and off depending on signals from the sensor device when a further predetermined or predeterminable humidity value is exceeded.

From the EP 1 820 690 B1 A motor vehicle seat system is known which is designed to provide climate control essentially on the surface of a vehicle seat by means of sensor arrangements and feedback controls, wherein humidity and temperature sensors as well as a ventilation arrangement and/or heating arrangement are used.

The object of the invention is to provide an alternative method for air conditioning a vehicle seat occupied by a vehicle occupant, with regard to the prior art, by means of which said air conditioning of the vehicle seat is or can be carried out in an even more comfortable manner. Air conditioning is understood to mean both the ventilation and heating of a vehicle seat and thus also of the vehicle occupant. Furthermore, the object of the invention is to provide a vehicle, in particular a motor vehicle, with such an air-conditioned vehicle seat.

Starting from a method for air conditioning a vehicle seat occupied by a vehicle occupant, which in turn has a seat ventilation device and a seat heating device, wherein, using an electronic control and regulating unit (ECU), the seat ventilation device and the seat heating device are regulated and controlled as a function of an absolute contact humidity of a surface of the vehicle seat determined by means of at least one humidity sensor and a contact temperature of the vehicle occupant determined by means of at least one temperature sensor, and wherein the contact temperature of the vehicle occupant is determined by means of at least one temperature sensor of the vehicle seat and the regulation and control takes place in such a way that the contact temperature in the vehicle seat for the respective vehicle occupant is regulated and controlled to a value above a predetermined control reference value of the temperature with minimized seat heating power and the absolute contact humidity is regulated and controlled to a value below a predetermined control reference value of the absolute contact humidity with minimized seat ventilation power, the stated object is achieved in that the seat ventilation device and the seat heating device are regulated and controlled in additional dependence on a by means of at least one The heat flow between the vehicle occupant and the vehicle seat detected by the heat flow sensor can be regulated and controlled.

This measure advantageously takes into account the fact described above that the overall thermal comfort sensation of a vehicle occupant is significantly influenced by the contact area of the vehicle seat. With regard to the above-described DE 10 2014 206 613 A1 Accordingly, it is not the skin temperature of the face and/or hand area of the vehicle occupant that is used to climate control the vehicle seat, but rather a measured contact temperature directly in/on the vehicle seat, whereby the climate control of the vehicle seat can be regulated and controlled in a vehicle occupant-related manner, i.e., individually and thus with even greater emphasis on comfort. The basic idea of the invention is therefore to detect not only the contact humidity but also the contact temperature in the contact area between the vehicle occupant and the vehicle seat, and to adjust the individual comfort requirements of the vehicle occupant accordingly by appropriately controlling the seat ventilation and seat heating system. By regulating and controlling the contact temperature in the vehicle seat for the respective vehicle occupant with minimized seat heating power to a value above a predefined reference value for the temperature and the absolute contact humidity with minimized seat ventilation power to a value below a predefined reference value for the absolute contact humidity, this comfort state can be maintained with minimal energy consumption and largely unnoticeably for the vehicle occupant after the vehicle occupant has reached the comfort state with regard to contact humidity and contact temperature. Suitable heat flow sensors for this purpose have been available to specialists for some time and can, for example, be measured according to the DE 38 22 164 A1 Although heat flow sensors are known per se, the use of heat flow sensors or their measurement results for the regulation and control of air conditioning devices in vehicle seats has remained unknown to date.

The subclaims describe preferred developments or embodiments of the invention.

According to a first preferred variant, it is provided that, starting from an initially measured heat flow from the vehicle occupant to the vehicle seat, the additional dependency of the regulation and control of the seat ventilation device and the seat heating device is designed such that, when the seat heating device is operated to heat the vehicle occupant, the seat heating device is operated at a constant seat heating output until a heat flow from the vehicle seat to the vehicle occupant is measured. Subsequently, the seat heating output is continuously adjusted until, in the long term, a minimized heat flow or no heat flow at all flows between the vehicle seat and the vehicle occupant with the seat heating output minimized, and the temporal change in the heat flow reaches a constant minimum. The air conditioning of the vehicle seat therefore takes place without major step changes and is thus largely imperceptible to the vehicle occupant in question. This results in a state of approximately thermodynamic equilibrium between the vehicle occupant and the vehicle seat, which in turn results in a subjectively adjusted comfort contact temperature measured by the temperature sensor, which can be formed integrally by the heat flow sensor.

In a further development of the method, the corresponding contact temperature on the vehicle occupant is preferably measured in the state of a temporal change in the heat flow of a constant minimum, and the said contact temperature is stored in the control unit (ECU) as the optimal subjective comfort contact temperature of the vehicle occupant in question and used as a new control reference value for the contact temperature.

According to a second preferred variant, it is provided that, starting from a the initially measured heat flow from the vehicle occupant to the vehicle seat, the additional dependence of the regulation and control of the seat ventilation device and the seat heating device is designed in such a way that when the seat heating device is operated to heat the vehicle occupant, the seat heating device is operated at a constant seat heating output until a heat flow from the vehicle seat to the vehicle occupant is measured, and at a first transition point of the measured heat flow, the associated contact temperature is stored in the control and regulation unit (ECU) as a control reference value of a subjective comfort contact temperature of the vehicle occupant in question and is used as a new control reference value for the contact temperature, wherein the first transition point of the measured heat flow is understood to be the point which results when the measured heat flow from the vehicle occupant to the vehicle seat reverses into a heat flow from the vehicle seat to the vehicle occupant. This reversal is also referred to in the specialist world as a zero crossing with regard to a heat flow-time diagram created for this purpose.

Assuming that only the seat heating system is subsequently used to air condition the vehicle seat, either the said comfort contact temperature can be used as a guideline for the control unit (ECU) or it can continue to be controlled in additional dependence on the recorded heat flow.

If, on the other hand, the seat ventilation system is activated due to a predefined humidity limit or threshold being exceeded in the contact area between the vehicle occupant and the vehicle seat, which humidity limit or threshold corresponds to the reference value for absolute contact humidity, it is preferably provided that the seat heating system is regulated and controlled exclusively as a function of the stored comfort contact temperature, preferably the last subjectively determined comfort contact temperature used, as a reference value for the control unit (ECU). The humidity limit is generally understood to be the tolerable limit for a resting, unclothed person without any water supply regarding high room temperature and humidity at a constant, very low wind speed (10 cm/s). Experience has shown that this humidity limit is approximately 12 g of humidity per kg of air.

Furthermore, if the seat ventilation system is activated due to a premature exceedance of a predefined humidity limit or threshold value, which corresponds to the standard reference value for the absolute contact humidity, in the contact area between the vehicle occupant and the vehicle seat, the seat heating system is preferably regulated and controlled depending on the comfort contact temperature recorded and stored during a previous journey as a reference value for the control and regulation unit (ECU). This is preferably done with the inclusion of person detection. If such a reference value is not stored or the vehicle occupant cannot be recognized, it is preferably provided that the seat heating system is regulated and controlled based on a standard value of said reference value for the contact temperature. As far as the premature exceedance of the predefined humidity limit or threshold value is concerned, this circumstance can be caused, for example, by physical activity performed by the vehicle occupant in question before entering the vehicle.

As an alternative to the above procedures, however, it is also possible for the vehicle occupant to specify defined standard values for the contact temperature or contact humidity according to individual needs or to shift the standard values determined according to the procedural procedure described above according to individual needs by automatically increasing or decreasing the standard values for the contact temperature stored in the control unit (ECU) by a predetermined differential temperature value.

As already indicated above, it is preferably provided that both the heat flow and the contact temperature are detected by means of the at least one heat flow sensor, which results in particular in savings in material as well as in regulation and control expenditure.

The stated object is further achieved according to the invention by a vehicle, in particular a motor vehicle, having the features of claim 10. Advantageous embodiments of the invention emerge from the further claims.

For this purpose, in a vehicle with a vehicle seat, which vehicle seat has a seat ventilation device and a seat heating device, with at least one humidity sensor for detecting an absolute humidity value of a contact surface of the vehicle seat, with at least one temperature sensor for detecting a contact temperature of a vehicle occupant and with a regulating and control unit (ECU), which generates regulating and control signals for said seat ventilation device and/or seat heating device depending on the detected humidity value and/or the detected contact temperature, that the temperature sensor is arranged in the region of said contact surface, and that the control unit (ECU) is configured to control and regulate the seat ventilation device and the seat heating device according to a method of the type described above. The at least one heat flow sensor is arranged between the seat heating device and the vehicle occupant positioned on the vehicle seat, resulting in reliable measurement with easily usable measurement results. Furthermore, the at least one temperature sensor is formed by a heat flow sensor, which allows the air conditioning of the vehicle seat to be optimized.

Based on the knowledge that the comfort contact temperature of the vehicle occupant can be different for a backrest and for a seat cushion of the vehicle seat, it is preferably provided that said backrest and said seat cushion of the vehicle seat each have a seat ventilation device and a seat heating device as well as at least one temperature sensor in the form of a heat flow sensor which can detect both heat flow values and temperature values, and that the regulating and control device - ECU - is set up to carry out the ventilation and heating of the backrest and the seat cushion separately from one another by regulating and controlling the relevant seat ventilation device and seat heating device.

• 1 äußerst schematisch ein Fahrzeug in einer Seitenansicht mit einem erfindungsgemäß klimatisierbaren Fahrzeugsitz,
• 2 ein klimatisierbarer oder bereits klimatisierter und mit einem Fahrzeuginsassen besetzter Fahrzeugsitz in einer Einzelansicht,
• 3 ein Flussdiagramm bzgl. einer äußerst einfachen Ausführungsform des erfindungsgemäßen Verfahrens unter Zuhilfenahme eines Wärmestromsensors,
• 4 ein Diagramm mit der Darstellung des Verlaufs der Wärmestromdichte respektive des Wärmestroms eines nach dem erfindungsgemäßen Verfahren klimatisierten Fahrzeugsitzes, und
• 5 ein Diagramm mit der Darstellung des Verlaufs der Wärmestromdichte respektive des Wärmestroms eines nach dem erfindungsgemäßen Verfahren klimatisierten Fahrzeugsitzes in einer Variation zu 4.

The invention is explained in more detail below with reference to the exemplary embodiments schematically illustrated in the drawings. However, it is not limited to these, but encompasses all embodiments defined by the patent claims. They show:

• 1 extremely schematically a vehicle in a side view with a vehicle seat that can be air-conditioned according to the invention,
• 2 a vehicle seat that can be air-conditioned or is already air-conditioned and occupied by a vehicle occupant in a single view,
• 3 a flow chart relating to an extremely simple embodiment of the method according to the invention with the aid of a heat flow sensor,
• 4 a diagram showing the course of the heat flux density or the heat flow of a vehicle seat air-conditioned according to the method according to the invention, and
• 5 a diagram showing the course of the heat flux density or the heat flux of a vehicle seat air-conditioned according to the method according to the invention in a variation of 4 .

1 shows, initially, very schematically, a vehicle 1, in this case a passenger car, which has at least one vehicle seat 2 which can be air-conditioned according to the invention. 2 shows a highly schematic representation of said air-conditioned vehicle seat 2, which is occupied by a vehicle occupant 3. The vehicle seat 2 has a seat ventilation device 4 of the blowing or suction type with, according to this exemplary embodiment, two preferably electrically operated seat blowers 4a, 4b, which serve to ventilate the vehicle seat 2 or the surface 5 thereof in the contact area between the vehicle occupant 3 and the vehicle seat 2. In the present case, a seat blower 4a is provided for ventilating a backrest 2a and a seat blower 4b is provided for ventilating a seat cushion 2b of the vehicle seat 2. The seat blowers 4a, 4b are connected to said contact surface 5 via air ducts 6. In addition, the vehicle seat 2 has a seat heating device 7, which, according to this exemplary embodiment, is formed by two preferably electrically operated heating elements 7a, 7b, more preferably by two surface heating elements 7a, 7b. Both the backrest 2a and the seat cushion 2b have such a heating element 7a and 7b, respectively. The heating elements 7a, 7b are preferably arranged directly beneath the cover of the backrest 2a and the seat cushion 2b. Furthermore, the backrest 2a and the seat cushion 2b each have a humidity sensor 8 and a temperature sensor 9.

Humidity sensors 8 and temperature sensors 9 are also preferably arranged directly beneath the cover of the backrest 2a and the seat cushion 2b. The seat ventilation device 4 or its seat blower 4a, 4b and the seat heating device 7 or its heating elements 7a, 7b are preferably controlled and regulated separately from one another with regard to their ventilation or heating output, if necessary, by an electronic control unit (ECU) 10, which receives measurement signals 11, 12 from the humidity sensors 8 and temperature sensors 9 and, upon evaluation thereof, generates corresponding control signals 13, 14 for the seat ventilation and seat heating devices 4, 7.

According to one embodiment of the method, the air conditioning of the relevant vehicle seat 2 is initially started, for example after the start of the vehicle 1 or as a result of a sensed occupancy of the vehicle seat 2 with preferably person detection. This leads to a contact temperature and contact humidity measurement in the area of the surface 5 of the backrest 2a and the seat cushion 2b, respectively in the contact area between the vehicle occupant 3 and the vehicle seat 2, by means of the humidity sensors 8 and temperature ture sensors 9. The regulation and control of the seat ventilation and seat heating device 4, 7 now takes place in such a way that the contact temperature in the vehicle seat 2 for the relevant vehicle occupant 3 is regulated and controlled to a value above a predetermined control reference value of the temperature with minimized seat heating power and the absolute contact humidity is regulated and controlled to a value below a predetermined control reference value of the absolute contact humidity with minimized seat ventilation power.

In detail, this procedure means that after reaching the comfort state of the vehicle occupant with regard to contact humidity and contact temperature, which are predetermined by said standard values or fixed predefined values, the individual comfort state of the vehicle occupant is maintained with minimal energy expenditure and largely imperceptibly for the vehicle occupant 3.

• Um die Klimatisierung weiter zu optimieren, ist für die Rückenlehne 2a und das Sitzkissen 2b je ein Wärmestromsensor 9' vorgesehen. Es ist ein Wärmestromsensor 9' eingesetzt, welcher sowohl Wärmestromwerte als auch Temperaturwerte detektieren kann. Demnach ist vorgesehen, dass die Sitzbelüftungseinrichtung 4 und die Sitzheizeinrichtung 7 in zusätzlicher Abhängigkeit des mittels des vorliegend vorgesehenen Wärmestromsensors 9' erfassten Wärmestroms zwischen dem Fahrzeuginsassen 3 und dem Fahrzeugsitz 2 geregelt und gesteuert werden. Besagter Wärmestromsensor 9' liefert die Information, inwieweit ein Wärmestrom vom Fahrzeuginsassen 3 zum Fahrzeugsitz 2 oder vom Fahrzeugsitz 2 zum Fahrzeuginsassen 3 fließt.

Embodiment of the invention:

• To further optimize climate control, a heat flow sensor 9' is provided for each of the backrest 2a and the seat cushion 2b. A heat flow sensor 9' is used, which can detect both heat flow values and temperature values. Accordingly, it is provided that the seat ventilation device 4 and the seat heating device 7 are regulated and controlled in addition as a function of the heat flow between the vehicle occupant 3 and the vehicle seat 2, which is detected by the heat flow sensor 9' provided here. Said heat flow sensor 9' provides information on the extent to which a heat flow flows from the vehicle occupant 3 to the vehicle seat 2 or from the vehicle seat 2 to the vehicle occupant 3.

3 shows, merely by way of example, a particularly simple embodiment of the method with the aid of a heat flow sensor 9', wherein the air conditioning is carried out exclusively by means of the seat heating device 7, since a humid limit is not exceeded. Accordingly, if a heat flow is sensed starting from a functional step 15, which comprises a separate heat flow measurement for the backrest 2a and the seat cushion 2b, the relevant heating element 7a, 7b of the seat heating device 7 is activated or remains active in functional step 16a. If such a heat flow is not recorded or if a heat flow flows instead from the vehicle seat 2 to the vehicle occupant 3, the heating output of the relevant heating element 7a, 7b is reduced in functional step 16b or the relevant heating element 7a, 7b is deactivated.

In particular, starting from an initially measured heat flow from the vehicle occupant 3 to the vehicle seat 2, i.e. measured when the vehicle occupant 3 occupies the relevant vehicle seat 2, the aim is to operate the seat heating device 7 or its heating element 7a, 7b with a constant seat heating output when heating the vehicle occupant 3, until a heat flow from the vehicle seat 2 to the vehicle occupant 3 is measured and subsequently to continuously adjust the seat heating output until, in the long term, a minimized heat flow or no heat flow at all flows between the vehicle seat 2 and the vehicle occupant 3 with minimized seat heating output and the temporal change in the heat flow reaches a constant minimum. This then results in heat flow curves, as shown for example in the 4 and 5 are shown.

Compared to the previously described control based exclusively on the specified control reference value of the contact temperature, this approach has the advantage that the individual conditions of the respective vehicle occupant 3, which are determined, for example, by clothing or insulation, any previously performed activities, the thermophysiology of the vehicle occupant 3, and/or the like, are taken into account. This results in a state of approximately thermodynamic equilibrium between the vehicle occupant 3 and the vehicle seat 2, which in turn results in a subjectively adjusted comfort contact temperature measured by the heat flow sensor 9'.

This allows the contact temperature measured on the vehicle occupant 3 in the state of temporal change of the heat flow constant minimum to be stored as the optimal subjective comfort contact temperature of the same in the control and regulation unit (ECU) 10 and to be used as a new control reference value for the contact temperature.

Tests on the subject matter of the application have shown that the measured contact temperature at the time of the zero crossing (cf. 4 and 5 ) of the heat flow, which is also referred to as transition point 17, is very well suited to determining the subjective comfort contact temperature of the vehicle occupant 3. The said first transition point 17 of the measured heat flow is therefore understood to be the point that results when the measured heat flow from the vehicle occupant 3 to the vehicle seat 2 reverses into a heat flow from the vehicle seat 2 to the vehicle occupant 3.

This results in an alternative procedure to the procedure described above, according to which, starting from an initially measured heat flow from the vehicle occupant 3 to the vehicle seat 2, the additional dependence of the Regulation and control of the seat ventilation device 4 and the seat heating device 7 is designed such that when the seat heating device 7 is operated to heat the vehicle occupant 3, the seat heating device 7 is operated as described with a constant seat heating output until a heat flow from the vehicle seat 2 to the vehicle occupant 3 is measured, and now, in contrast to the procedure described above, at the said first transition point 17 of the measured heat flow, the associated contact temperature is stored in the control and control unit (ECU) 10 as a control reference value of a subjective comfort contact temperature of the vehicle occupant in question and used as a new control reference value for the contact temperature. With reference to the 4 and 5 This means that the seat heating device 7 heats constantly, preferably with maximum heating power, until the said transition point 17 or zero crossing of the curve, and subsequently the heating power is reduced. 5 A second or further transition point 17' may also occur until the heat flow reaches a constant minimum, with the curve adhering to the zero line of the diagram. This means that the resulting curve oscillates around the said zero line with decreasing oscillation width as time progresses.

If the seat heating device 7 continues to be used without the seat ventilation device 4 during the further course of the journey, either the subjective comfort contact temperature which resulted during heating (as described above) can be used as a control reference value for the regulation and control of the seat heating output or it can continue to be used in addition as a function of the recorded heat flow (cf. 3 ) can be regulated and controlled.

The embodiments or variants of the method according to the invention described above are based on the fact that ventilation of the vehicle seat 2 is unnecessary.

However, if, during further travel, the seat ventilation device 4 is additionally activated with fully automatic comfort control because the humidity limit or threshold in the contact area between the vehicle occupant 3 and the vehicle seat 2 has been exceeded, whereby the humidity limit or threshold corresponds to the control reference value of the absolute contact humidity, the seat heating device 7 is regulated and controlled exclusively as a function of the subjectively determined and stored comfort contact temperature, preferably the last used comfort contact temperature, as a reference value for the control and regulation unit (ECU) 10. As already explained above, the said humidity limit is generally understood to be the tolerable limit for a resting, unclothed person without any water supply with regard to high room temperature and humidity at a constant, very low wind speed (10 cm/sec). Experience has shown that the said humidity limit is approximately 12 g of humidity per kg of air.

Furthermore, assuming that the seat ventilation system 4 is activated due to a premature exceedance of the predefined humidity limit or threshold value in the contact area between the vehicle occupant 3 and the vehicle seat 2, the seat heating system is preferably regulated and controlled as a reference value for the control unit (ECU) 10 based on the comfort contact temperature recorded and stored during a previous journey. This preferably takes place with the inclusion of person detection. Regarding the premature exceedance of the predefined humidity limit or threshold value, this circumstance can be caused, for example, by physical activity performed by the vehicle occupant 3 in question before entering the vehicle.

If, however, such a guideline value is not stored or the vehicle occupant 3 cannot be recognized, it is preferably provided that the seat heating device is regulated and controlled on the basis of a standard value of said guideline value of the contact temperature.

As an alternative to the above procedures, however, it is also possible for the vehicle occupant 3 to specify defined standard values for the contact temperature or contact humidity according to individual needs or to shift the standard values determined according to the procedural procedure described above according to individual needs by automatically increasing or decreasing the standard values for the contact temperature stored in the control and regulation unit (ECU) 10 by a predetermined differential temperature value.

list of reference symbols

1

vehicle

2

vehicle seat

2a

backrest

2b

seat cushion

3

Vehicle occupant

4

Seat ventilation system

4a

Seat blower

4b

Seat blower

5

surface

6

Air duct

7

Seat heating system

7a

heating element

7b

heating element

8

Humidity sensor

9

Temperature sensor

9'

Heat flow sensor

10

electronic control unit (ECU)

11

measurement signal

12

measurement signal

13

Control and regulation signal

14

Control and regulation signal

15

Functional step heat flow measurement

16a

Function step seat heating activated/active

16b

Function step seat heating deactivated/reduced

17

Transition point / zero crossing

17'

Transition point / zero crossing

Claims (11)

Method for air conditioning a vehicle seat (2) occupied by a vehicle occupant (3), which in turn has a seat ventilation device (4) and a seat heating device (7), wherein, using an electronic control unit - ECU - (10), the seat ventilation device (4) and the seat heating device (7) are controlled and regulated as a function of an absolute contact humidity of a surface (5) of the vehicle seat (2) determined by means of at least one humidity sensor (8) and a contact temperature of the vehicle occupant (3) determined by means of at least one temperature sensor (9), and wherein the contact temperature of the vehicle occupant (3) is determined by means of at least one temperature sensor (9) of the vehicle seat (2), and the control and regulation are carried out in such a way that, with minimized seat heating power, the contact temperature in the vehicle seat (2) for the relevant vehicle occupant (3) is set to a value above a predetermined control reference value of the temperature and the absolute contact humidity is set to a value below a predetermined The system is characterized in that the seat ventilation device (4) and the seat heating device (7) are regulated and controlled in additional dependence on a heat flow between the vehicle occupant (3) and the vehicle seat (2) detected by means of at least one heat flow sensor (9'). Procedure according to Claim 1 , characterized in that , starting from an initially measured heat flow from the vehicle occupant (3) to the vehicle seat (2), the additional dependency of the regulation and control of the seat ventilation device (4) and the seat heating device (7) is designed in such a way that when the seat heating device (7) is operated to heat the vehicle occupant (3), the seat heating device (7) is operated with a constant seat heating output until a heat flow from the vehicle seat (2) to the vehicle occupant (3) is measured and, subsequently, the seat heating output is continuously adjusted until, in the long term, with the seat heating output minimized, a minimized heat flow or no heat flow at all flows between the vehicle seat (2) and the vehicle occupant (3) and the temporal change in the heat flow reaches a constant minimum. Procedure according to Claim 2 , characterized in that in the state of a temporal change in the heat flow of constant minimum, the contact temperature corresponding thereto is measured on the vehicle occupant (3) and the said contact temperature is stored as the optimal subjective comfort contact temperature of the vehicle occupant (3) in question in the regulating and control device - ECU - (10) and is used as a new control reference value for the contact temperature. Procedure according to Claim 1 , characterized in that starting from an initially measured heat flow from the vehicle occupant (3) to the vehicle seat (2), the additional dependency of the regulation and control of the seat ventilation device (4) and the seat heating device (7) is designed in such a way that when the seat heating device (7) is operated to heat the vehicle occupant (3), the seat heating device (7) is operated with a constant seat heating power until a heat flow from the vehicle seat (2) to the vehicle occupant (3) is measured, and at a first transition point (17) of the measured heat flow, the associated contact temperature is stored as a control reference value of a subjective comfort contact temperature of the relevant vehicle occupant (3) in the control and control device - ECU - (10) and is used as a new control reference value for the contact temperature, wherein the first transition point (17) of the measured heat flow is understood to be the point which results when the measured heat flow from the vehicle occupant (3) to the vehicle seat (2) changes into a heat flow from Vehicle seat (2) is reversed towards the vehicle occupant (3). Method according to one of the preceding claims, characterized in that , in the case where only the seat heating device (7) is used for air conditioning the vehicle seat (6), then either the said comfort contact temperature is used as a guide value for the regulating and control device - (ECU - (10)) or is further regulated and controlled in additional dependence on the detected heat flow. Method according to one of the preceding claims, characterized in that in the event that the seat ventilation device (4) is activated due to a predetermined humidity limit or threshold value being exceeded in the contact area between the vehicle occupant (3) and the vehicle seat (4), which humidity limit or threshold value corresponds to the control guide value of the absolute contact humidity, the seat heating device (7) is regulated and controlled exclusively as a function of the stored comfort contact temperature as a guide value for the control and regulating device - ECU - (10). Method according to one of the preceding claims, characterized in that in the event that the seat ventilation device (4) is activated due to a premature exceeding of a predetermined humidity limit or threshold value, which corresponds to the control reference value of the absolute contact humidity, in the contact area between the vehicle occupant (3) and the vehicle seat (2), either the seat heating device (7) is regulated and controlled as a function of the comfort contact temperature recorded and stored during a previous journey as a reference value for the control and regulating device - ECU - (10), or if such a reference value is not stored, the seat heating device (7) is regulated and controlled on the basis of a standard value of said reference value of the contact temperature. Method according to one of the preceding claims, characterized in that the vehicle occupant (3) specifies defined control values for the contact temperature or contact humidity or which, according to the procedure according to Claim 4 or 5 determined control reference values by automatically increasing or decreasing the control reference values for the contact temperature stored in the control and regulation device - ECU - (10) by a predetermined differential temperature value. Method according to one of the Claims 1 until 8 , characterized in that both the heat flow and the contact temperature are detected by means of the at least one heat flow sensor (9'). Vehicle (1) with a vehicle seat (2), which vehicle seat (2) has a seat ventilation device (4) and a seat heating device (7), with at least one humidity sensor (8) for detecting an absolute humidity value of a contact surface (5) of the vehicle seat (2), with at least one temperature sensor (9) for detecting a contact temperature of a vehicle occupant (3), and with a regulating and control device - ECU - (10) which, depending on the detected humidity value and/or the detected contact temperature, generates regulating and control signals (13, 14) for said seat ventilation device (4) and/or seat heating device (7), wherein the temperature sensor (9) is arranged in the region of said contact surface (9), characterized in that the at least one temperature sensor (9) is arranged between the seat heating device (7) and the vehicle occupant (3) placed on the vehicle seat (2) and is formed by a heat flow sensor (9'), which measures both heat flow values and Temperature values can be detected, and that the regulating and control device - ECU - (10) is set up to control the seat ventilation device (4) and the seat heating device (7) according to a method according to one of the Claims 1 until 9 to regulate and control. Vehicle (1) to Claim 10 , characterized in that a backrest (2a) and a seat cushion (2b) of the vehicle seat (2) each have a seat ventilation device (4) and a seat heating device (7) and at least one temperature sensor (9) in the form of a heat flow sensor (9') which can detect both heat flow values and temperature values, and in that the regulating and control device - ECU - (10) is set up to carry out the ventilation and heating of the backrest (2a) and the seat cushion (2b) separately from one another by regulating and controlling the relevant seat ventilation device (4) and seat heating device (7).

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