Method for air conditioning a vehicle seat and motor vehicle

Abstract

Method for air conditioning a vehicle seat occupied by a vehicle occupant, which is equipped with a seat ventilation device and a seat temperature control device, wherein a humidity sensor arrangement is used to determine the humidity of a surface The representative humidity value of the vehicle seat is determined, and the seat ventilation and temperature control systems are controlled depending on the determined humidity value. characterized by that the seat ventilation device and the seat temperature control device are additionally controlled depending on a skin temperature value detected by means of a temperature sensor arrangement and representative of the skin temperature of the face and / or hand area of ​​the vehicle occupant, wherein the control dependency of the seat ventilation system and the The seat temperature control device is designed such that, if a humidity value is detected above a predetermined humidity limit, the seat ventilation device is activated or its activation is enhanced, provided that the detected skin temperature value is above a predetermined temperature limit.

Description

Field of the invention

[0001] The invention relates to a method for air conditioning a vehicle seat occupied by a vehicle occupant, which is equipped with a seat ventilation device and a seat temperature control device, wherein a humidity value representative of a humidity of a surface of the vehicle seat is determined by means of a humidity sensor arrangement and the seat ventilation device and the seat temperature control device are controlled as a function of the determined humidity value.

[0002] The invention further relates to a motor vehicle comprising - a vehicle seat which is equipped with a seat ventilation device and a seat temperature control device, - a humidity sensor arrangement for detecting a humidity value representative of a surface of the vehicle seat and - a control unit configured to control the seat ventilation device and the seat temperature control device depending on the humidity value. State of the art

[0003] Such methods and motor vehicles are known from DE 102 38 552 A1.

[0004] This document discloses a motor vehicle with a complex climate control system coordinated by a control unit that, on the one hand, receives signals from various climate parameter sensors in the interior of the motor vehicle and, on the other hand, controls various climate parameter influencing devices in the interior of the motor vehicle. In particular, the cited document discloses equipping a vehicle seat with temperature and humidity sensors, which report current temperature and humidity values ​​in the surface area of ​​the vehicle seat occupied by a vehicle occupant to the control unit. The known vehicle seat is also equipped with a ventilation device and a temperature control device, in particular a heating device, both of which can be controlled by the control unit.The seat ventilation device is designed, in a manner generally known to those skilled in the art, to generate an airflow that permeates the material surface of the vehicle seat, thereby removing moisture present in the material or on its surface or contributing to its evaporation. The control unit of the known device stores temperature and humidity limit values ​​and implements algorithms that relate current temperature and humidity measured values ​​to the aforementioned limit values ​​and, if applicable, other measured and stored values. From this, they calculate control parameters for the seat ventilation device and the seat temperature control device, so that these devices are subsequently controlled accordingly.

[0005] The known device does aim to increase the climate comfort of the vehicle occupant, in particular by removing excessive humidity in the seating area. However, the known device does not take into account that the ventilation measure itself can be associated with a considerable reduction in comfort under certain climatic conditions. In particular when there is a large excess of humidity, the ventilation measure releases considerable evaporative cooling, which can be perceived as unpleasant by the vehicle occupant, especially if they are already hypothermic. Such a situation can arise, for example, if the vehicle occupant has just walked through cold rain to get to their vehicle. In this case, a dry seat, i.e. the intended result of the known method, would certainly be desirable; however, the method for achieving this, i.e. strong seat ventilation, would at least temporarily increase the discomfort.Although the aforementioned publication suggests heating the driver's seat as a compensatory measure, the climate control is based solely on humidity and temperature measurements related to the seat surface and is therefore not very representative of the vehicle occupant's current perceived climate comfort.

[0006] From DE 199 53 385 A1 it is known to control additional seat heating according to current temperature and humidity measurements in the area of ​​the seat surface when the seat ventilation is switched on manually.

[0007] JP 2008 168 769 A discloses the detection of a vehicle occupant's body temperature before or during boarding by means of thermographic recording of their facial temperature. This information is used to immediately control a local climate control unit in the vehicle, in particular a seat heater or cooler, in order to create a comfortable temperature in the vehicle interior as quickly as possible after or, if possible, already during boarding. Task

[0008] It is the object of the present invention to provide an improved method for air conditioning a vehicle seat, which particularly also meets the requirements of situations in which there is a considerable excess of moisture and at the same time the vehicle occupant feels cold. Description of the invention

[0009] This object is achieved in conjunction with the features of the preamble of claim 1 in that the seat ventilation device and the seat temperature control device are controlled in additional dependence on a skin temperature value detected by means of a temperature sensor arrangement and representative of a skin temperature of the face and / or hand area of ​​the vehicle occupant, wherein the control dependence of the seat ventilation device and the seat temperature control device is designed in such a way that when the detected humidity value is above a predetermined humidity limit value, the seat ventilation device is activated or activated more intensively under the additional condition that the detected skin temperature value is above a predetermined temperature limit value.

[0010] With regard to a correspondingly equipped motor vehicle, this object is achieved in conjunction with the features of the preamble of claim 4 in that the vehicle further comprises a temperature sensor arrangement for detecting a skin temperature value representative of a skin temperature of the face and / or hand area of ​​a vehicle occupant positioned on the vehicle seat, and the control unit is configured to control the seat ventilation device and the seat temperature control device in additional dependence on the skin temperature value according to the aforementioned method according to the invention.

[0011] Preferred embodiments of the invention are the subject of the dependent claims.

[0012] The central idea of ​​the invention is not only to detect the need for seat ventilation, especially seat drying, as such and to design appropriate seat ventilation or drying measures accordingly. Rather, the focus is on the subjective comfort perception of the vehicle occupant.

[0013] According to the invention, before a seat ventilation measure is initiated, it can be checked whether such a measure is compatible with the current perception of comfort of the vehicle occupant. As an objectively measurable parameter for recording the subjective perception of comfort, the skin temperature in the face and / or hand area of ​​the vehicle occupant is used according to the invention. In particular, below a so-called PMV value of zero, i.e. a thermal comfort index defined according to DIN EN ISO 7730, the skin temperature in the face and hand area is very strongly correlated with the current perception of comfort. A PMV value below zero means that the majority of people perceive a corresponding climate parameter constellation as overall cool, cold, or too cold (of course, other definitions of comfort values ​​are also applicable within the scope of the invention).The skin temperature value detected according to the invention is therefore a very sensitive indicator, especially in the range of interest here, of whether and, if so, by how much the currently perceived thermal comfort deviates from the optimum. Therefore, the invention makes it possible to estimate whether, and if so, to what adjustable intensity, a seat ventilation measure is justifiable with regard to avoiding additional discomfort or, preferably, increasing comfort in view of the current perception of comfort. Thus, the invention provides that the control dependency of the seat ventilation device and the seat temperature control device is designed such that, if the detected humidity value is above a predetermined humidity limit, the seat ventilation device is activated or activated more intensively under the additional condition that the detected skin temperature value is above a predetermined temperature limit.In other words, the skin temperature value detected by the temperature sensor array is compared with a temperature threshold stored in the control unit. The stored threshold can be static or calculated based on current measured values, such as ambient climate values. If the detected skin temperature value exceeds the stored temperature threshold, this is interpreted as meaning that the thermal comfort currently perceived by the vehicle occupant is sufficiently high in the warm range, so that seat ventilation would not lead to an unacceptable reduction in comfort, leading to an excessively cool sensation, but rather, in the best case, to an increase in comfort. Accordingly, this criterion is considered sufficient to initiate the ventilation measure.This ventilation measure can involve activating a previously inactive seat ventilation system or increasing the activity of an already active seat ventilation system.

[0014] However, if the recorded skin temperature value is below the stored temperature threshold, two different consequences can essentially be drawn. The choice of these in a specific case can be made dependent on other current measured values, such as the current ambient climate.

[0015] In a first variant, the control dependency of the seat ventilation system and the seat temperature control system is configured such that, if a detected humidity value above the specified humidity limit and a detected skin temperature value below the specified temperature limit are simultaneously present, the seat temperature control system is activated or increased, and the seat ventilation system is not activated or increased. This essentially means that if the vehicle occupant already perceives their current thermal situation as too cold, no seat ventilation measure is implemented, which would further exacerbate this discomfort. Instead, the seat is heated or the seat heating is increased.While this does not immediately dry the seat, the vehicle occupant is warmed up to the point where they can withstand the drying measures without unacceptable loss of comfort. When the method according to the invention is implemented iteratively, this point in time is detected by the inventive skin temperature detection, so that the method then switches to the basic mode explained above.

[0016] Alternatively, in a second variant, the control dependency of the seat ventilation system and the seat temperature control system can be configured such that, if a detected humidity value above the specified humidity limit and a detected skin temperature value below the specified temperature limit are simultaneously present, the seat ventilation system is activated or its activation is amplified while the seat temperature control system is simultaneously activated or its activation is amplified. This essentially means that the thermal discomfort detected based on the skin temperature is compensated for in parallel with the initiated drying measures. Seat ventilation and seat heating are thus activated or their activity amplified simultaneously.This variant leads more quickly to the desired result of a dry seat; however, its effectiveness with regard to discomfort compensation depends on several criteria, such as the extent of the current discomfort and the technical implementation of the seat temperature control device and the seat ventilation device. The person skilled in the art will therefore have to consider these parameters when specifically designing the method according to the invention when deciding whether to choose the above-mentioned first or the second variant of the further development of the invention described here.

[0017] For the specific technical implementation of the temperature sensor arrangement for detecting the skin temperature of the vehicle occupant, it can be provided that it has a contactless infrared temperature sensor directed at the face and / or hand area of ​​the vehicle occupant. Such contactless temperature sensors are known to those skilled in the art. Their use appears particularly helpful in the present context, since any other method of detecting the skin temperature, especially facial skin temperature, is uncomfortable for the vehicle occupant.

[0018] Alternatively or additionally, however, the temperature sensor arrangement can also include a temperature sensor integrated into a manual actuator of the vehicle. Such a contact measurement is particularly suitable for detecting skin temperature in the hand area. Such temperature sensors can be integrated, for example, into the steering wheel or a gear knob.

[0019] Further features and advantages of the invention will become apparent from the following specific description and drawings. Short description of the drawing

[0020] It shows: Fig. 1 a flowchart of an embodiment of the method according to the invention. Detailed description of preferred embodiments

[0021] The same reference numerals in the figures indicate the same or analogous elements.

[0022] Fig. Figure 1 shows a particularly simple embodiment of the method according to the invention in the form of a flowchart. Practical embodiments of the invention are likely to be significantly more complex. The simple variant of Fig. However, Figure 1 has been chosen for illustrative purposes as it appears particularly suitable for clarifying the principles of the invention.

[0023] The method 100 begins with a start step 10. This start step can be initiated, for example, when the vehicle is started or when the general air conditioning system is activated. In a first functional step 12, a humidity measurement is taken in the contact area of ​​a vehicle seat with a vehicle occupant positioned there. It is considered advantageous if such a humidity measurement step is preceded by occupancy detection in order to avoid unnecessary application of the method according to the invention to unoccupied vehicle seats, which would be associated with unnecessary energy consumption. To carry out the humidity measurement, the vehicle seat is equipped with suitable humidity sensors, which are generally known to those skilled in the art and can be designed and positioned in accordance with the requirements of the individual case. The determined humidity values ​​are sent to the control unit.In a decision step 14 performed by the control unit, the determined humidity values ​​are compared with stored humidity threshold values ​​to determine whether ventilation or drying of the vehicle seat is necessary. If this is not the case, the method essentially returns to the preferably periodically performed humidity measurement 12. A test step 16 can be provided to check whether the seat ventilation device is (still) active. If this is the case, it can be deactivated in a further functional step 18; otherwise, the method immediately returns to the preferably periodic humidity measurement.

[0024] If the decision in decision step 14 is positive, i.e., if the seat is assessed as being too humid and in need of ventilation, the skin temperature of the vehicle occupant in the face and / or hand area is measured according to the invention in functional step 20. Such a measurement can be carried out (particularly for facial temperature measurements) without contact using IR temperature sensors or (particularly for hand temperature measurements) using contact sensors, for example in the steering wheel and / or a gear knob. The determined temperature values ​​are sent to the control unit, where a comparison with stored temperature limit values ​​is carried out in decision step 22. If it is determined that the determined skin temperature values ​​are below the stored temperature limit values, this is interpreted to mean that the current thermal comfort of the vehicle occupant does not permit seat ventilation.Instead, the method proceeds to functional step 24, in which the seat temperature control device, in particular a seat heater, is activated. The method then returns to the preferably periodically performed skin temperature measurement of functional step 20 and returns to decision step 22.

[0025] If it is determined in decision step 22 that the determined skin temperature values ​​are above the stored temperature limits, this is interpreted as meaning that the current thermal comfort of the vehicle occupant allows a ventilation measure. Accordingly, the seat ventilation device is activated in functional step 26. In the illustrated embodiment of Fig. 1, the ventilation activation step 26 is preceded by a query regarding the activity of the seat temperature control device. In this case, a check is carried out in decision step 28 to determine whether the seat temperature control device is (still) active. If so, it is deactivated in functional step 30. Otherwise, the method proceeds directly to the ventilation activation step 26. The method then returns to the humidity measurement step 12, which now serves to check the success of the ventilation measure of functional step 26.

[0026] At the Fig. In the particularly simple embodiment of the method according to the invention shown in Figure 1, the seat ventilation device and the seat temperature control device are activated strictly separately from one another. This separation serves solely to simplify the illustration. Those skilled in the art will readily recognize that more complex methods in which seat temperature control and seat ventilation can occur simultaneously or overlap each other are also possible. The same applies to the respective controlled activity intensity. The simplified method according to Fig. 1 only distinguishes between the states active and inactive, whereas in practice differentiated activity strength concepts are likely to be the rule.

[0027] Of course, the embodiments discussed in the specific description and shown in the figures represent only illustrative embodiments of the present invention. In light of the disclosure herein, a wide range of possible variations is available to those skilled in the art. List of reference symbols 100 procedures 10 Starting step 12 Function step 14 Decision step 16 Decision step 18 Function step 20 Function step 22 Decision step 24 Function step 26 Function step 28 Decision step 30 Function step

Claims

[1] Method for air conditioning a vehicle seat occupied by a vehicle occupant, which is equipped with a seat ventilation device and a seat temperature control device, wherein a humidity sensor arrangement is used to determine a humidity of a surface a representative humidity value is determined for the vehicle seat and the seat ventilation system and the seat temperature control system are controlled depending on the determined humidity value, characterized by , that the seat ventilation device and the seat temperature control device are controlled in additional dependence on a skin temperature value detected by means of a temperature sensor arrangement and representative of a skin temperature of the face and / or hand area of ​​the vehicle occupant, wherein the control dependency of the seat ventilation system and the The seat temperature control device is designed in such a way that, when the detected humidity value is above a predetermined humidity limit, the seat ventilation device is activated or activated more intensively under the additional condition that the detected skin temperature value is above a predetermined temperature limit. [2] Method according to claim 1, characterized by that the control dependency of the seat ventilation device and the seat temperature control device is designed in such a way that if a detected humidity value above the predetermined humidity limit value and a detected skin temperature value below the predetermined temperature limit value are present at the same time, an activation or activation amplification of the seat temperature control device takes place and an activation or activation amplification of the seat ventilation device does not take place. [3] Method according to claim 1, characterized bythat the control dependency of the seat ventilation device and the seat temperature control device is designed in such a way that if a detected humidity value above the predetermined humidity limit value and a detected skin temperature value below the predetermined temperature limit value are present at the same time, the seat ventilation device is activated or activated more strongly while the seat temperature control device is activated or activated more strongly. [4] Motor vehicle, comprising - a vehicle seat which is equipped with a seat ventilation device and a seat temperature control device, - a humidity sensor arrangement for detecting a humidity value representative of a surface of the vehicle seat and - a control unit configured to control the seat ventilation device and the seat temperature control device depending on the humidity value, characterized by that the vehicle further comprises a temperature sensor arrangement for detecting a skin temperature value representative of a skin temperature of the face and / or hand area of ​​a vehicle occupant positioned on the vehicle seat, and the control unit is configured to control the seat ventilation device and the seat temperature control device in additional dependence on the skin temperature value according to a method according to one of the preceding claims. [5] Motor vehicle according to claim 4, characterized by that the temperature sensor arrangement comprises a contactless infrared temperature sensor directed towards the face and / or hand area of ​​the vehicle occupant. [6] Motor vehicle according to one of claims 4 to 5, characterized by that the temperature sensor arrangement comprises a temperature sensor integrated into a manual actuating element of the vehicle.

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