DE10312077B3 - Passenger cabin temperature sensor for use in road vehicle consists of plug mounted in hole in instrument panel with sunlight sensor and NTC temperature sensor - Google Patents

Abstract

The plug housing (36) mounted in the instrument panel (18) may be transparent or translucent and incorporates a sunlight sensor (34) with a photodiode (54). The housing also incorporates a NTC resistor (52) to measure temperature. The two sensors are connected to a circuit board (56) and an evaluation circuit (58) via three conductors (44-48).

Description

The invention relates to a device to determine the temperature in a room with at least one in parts for Boundary wall permeable to solar radiation, and in particular a device for determining the temperature in the interior of a vehicle.

There are a variety of use cases in which the (air) temperature in a room is measured must become. For this purpose, a temperature sensor is used, which in one Measuring range of the room, i.e. in the surrounding the temperature sensor Area of the room that measures temperature.

Another application for a device For example, to determine the temperature in a room vehicle equipped with air conditioning. Such vehicles have one Interior temperature sensor, for design reasons hidden, mostly located in the air conditioning control unit. So that Interior temperature sensor can measure the temperature of the air in the passenger compartment the interior temperature sensor an air flow past, which is also arranged in the control unit ventilation motor is produced. For this purpose, the interior temperature sensor is inside a channel arranged in the over an opening to the passenger compartment through the ventilation motor air is sucked in.

This concept of metrological Determining the interior temperature has generally proven itself in practice. It However, it should be noted that the known systems are not free are from mistakes. So the system is, for example, by the existence of the ventilation motor against interference susceptible, on the one hand what the electrics and on the other hand the maintenance of the airflow. If namely for example the flow resistance due to an added air inlet opening of the duct, so is the interior temperature sensor not enough anymore ventilated and therefore can not be the indoor temperature in the sufficiently accurate Representing dimensions Deliver measurement signals. About that In addition, the interior temperature sensor may be in the flow air entrained Contaminate particles and thereby have measurement inaccuracies. This There is a particular danger in vehicles that smoke.

It has been tried several times the temperature detection in the interior of a vehicle by means of a Realize temperature sensor that is "unventilated".

For example, the DE 37 22 000 C2 a device for indoor temperature measurement, in which two temperature sensors are used. While one temperature sensor is arranged in the vicinity of a wall delimiting the interior and is surrounded by the air of the interior, a second temperature sensor is arranged directly on the surface of the wall. The actual interior temperature is then determined via a difference measurement of the output signals of the two temperature sensors, with additional consideration of a decoupling factor. Another device for indoor temperature measurement is in DE 41 30 063 A1 described.

Furthermore is off DE 100 49 979 A1 another device for determining the interior temperature of a vehicle without using a ventilation motor is known. This known device has a temperature sensor which is thermally coupled to a heat-conducting element which extends into the interior of the vehicle. The temperature sensor is arranged behind, for example, the front panel of the climate control device. In order to compensate for thermal conditions falsified due to solar radiation around the heat-conducting element, a sun sensor is provided in the known device. Furthermore, the known device has a further compensation sensor, which is a further temperature sensor which is arranged at a great distance from the aforementioned temperature sensor in the control device and is intended to compensate for thermal influences which have a negative effect on the actual temperature measurement.

Out DE 198 13 093 C1 it is known to arrange the interior temperature sensor of a vehicle air conditioning system together with a sun sensor on a common housing. While the sun sensor is arranged inside the material forming the housing, the temperature sensor, as the only interior temperature sensor of the air conditioning system, is located outside of this housing, but is arranged so that it is protected from the sun by a projection of the housing of the sun sensor. This combination of sensors is located on top of a vehicle instrument panel near the windshield.

The well-known indoor temperature measuring systems with unventilated sensors are unfortunately not yet so mature that the interior temperature in any temperature condition in which the passenger compartment and the located on these adjacent vehicle components can be determined precisely can.

The invention is based on the object Basically, a device for determining the temperature in one To create space, in particular the interior temperature of a vehicle, with which the temperature can be measured or determined precisely.

To solve this problem with the invention a device for determining the temperature in a room, in particular for indoor temperature determination proposed a vehicle that is provided with the features of claim 1. The subclaims relate to individual embodiments of the invention.

The peculiarity of the device according to the invention can be seen in the fact that the temperature sensor and a sun sensor is embedded together in the material forming the housing are. about the housing wall is the temperature sensor thermally coupled to the measuring area of the room that surrounds the housing. From the case lead out Connection elements (for example a lead frame). With the connection ends a processing unit is electrically connected to the measurement signals from the temperature sensor and receives from the sun sensor and from this an output signal representing the temperature in the room generated.

That the temperature sensor and the housing containing the sun sensor projects at least with one of its outer surfaces in into the room, this outer surface of the housing is preferably arranged in the boundary wall of the room or slight across from the boundary wall protrudes. The housing and the boundary wall are expediently thermally decoupled, for example by creating a distance between the housing and the boundary wall is realized. Behind the to the room adjacent outer surface of the housing conveniently located the temperature sensor, the only way through a thin Material layer (layer made of the material of the housing) from Space is separated. As a result, the temperature sensor is good thermal towards the room connected, which increases the temperature measurement accuracy.

Behind the outer surface of the housing there is also the sun sensor for detecting solar radiation. By measuring this solar radiation can the thermal heating of the the housing surrounding components as a result of solar radiation and a falsification the measurement signal of the temperature sensor can be compensated. ideal would it be, if the radiation sensitive area of the sun sensor directly the outer surface of the housing forms. However, this is not due to mechanical constraints possible. So it is imperative that the sun sensor through transparent Material is covered, otherwise the sun sensor or its Wiring (bond wire) damaged would. While on the sensitive area of the sun sensor, if it were to be exposed, light even under angles of incidence of almost 90 ° would be is this is easily done with an overlap of the sun sensor with a layer of material, as is the case with the housing the device according to the invention is given because of the light refraction and reflection properties the material layer is no longer possible. To the cosine-shaped Light incidence and intensity distribution of sunlight on a surface to be able to replicate a special configuration of the housing is required in the area of the housing outer surface adjacent to the interior. Various radii of curvature and / or play here Material properties and / or the installation position of the sun sensor relative to the outside surface certain role, which will be discussed in more detail below.

For example, it turned out to be proven appropriate if as housing shape the shape of a 5 mm standard LED (wired) is assumed. This standard case is changed in such a way that according to his rounded front end curvature areas with different radii of curvature having. According to the invention closes the cylindrical peripheral surface of the housing a first relatively strongly curved area whose radius is between 0.8 to 1.5 mm and in particular 1.2 to Is 1.4 mm. This relatively strongly curved area extends, when the housing is viewed on its exposed space Front side within an approximately 0.5 to 1.5 mm wide outer ring area, which is in particular 1.3 to 1.4 mm wide. Based on the total diameter of the housing is the width of this outer ring area preferably 1/6 to 1/4 of the diameter.

The one from the aforementioned outer ring area enclosed circular The central area of the front is convex and has a radius of curvature on that by at least an order of magnitude is bigger than the radius of curvature in the outer ring area, is more than 10 times this radius of curvature. Is expedient this radius of curvature larger than 10 mm and preferably larger than 30 mm.

Through the special described above convex Formation of the outer surface of the housing protruding into the room, which is continuously differentiable is at the transitions of the differently arched Sections thus has no edges, that is achieved too at angles of incidence close to 90 ° in sufficient measure incident solar radiation on the light-sensitive surface of the sensor incident.

Another not uninteresting The criterion is the installation position of the housing relative to its surroundings (e.g. front panel). Here it is useful if the housing is about Protrudes 1 mm.

In a further advantageous development of the invention it is provided that the chip height of the sun sensor is between 0.05 mm and 0.5 mm, the lead frame, that is to say the contact connections, at their ends projecting into the housing NEN distance from the outer surface of the housing of about 0.3 to 1.5 mm. The calculation index of the material used for the housing is between 1.0 and 1.8. This material can have a transmission filter so that it only lets light through in the visible wavelength range. In addition, this material can be mixed with diffuser particles (for example glass spheres), so that, viewed microscopically, a diffusion effect occurs.

In an advantageous development of the The invention further provides that the temperature sensor and the Sun sensor in the housing forming material are embedded. Trade in this material it is for example a plastic material and in particular a resin. The housing advantageously has the shape of a diode housing by a diving process is formed. Here you can look at the manufacturing techniques used to manufacture conventional LED housing (3 or 5 mm in diameter). An alternative manufacturing technique for the the temperature sensor and the housing for the sun sensor is, for example, the Plastic molding.

To reduce the influences on the temperature sensor due to heat conduction effects over the Connection elements is according to one Another advantageous embodiment of the invention provided that the temperature sensor over its electrical connection elements electrically decoupled from the the connecting elements connected units. This thermal Decoupling can be achieved either by forming the lines (thin and long) or by choosing the material of the connection elements (namely bad thermally conductive Material, such as steel) can be realized.

For further compensation of thermal influences the environment around the temperature sensor, for example caused by those adjacent to the measuring range heat-generating Components, it is an advantage to add a further temperature sensor determine, this further temperature sensor connected to the processing unit is and this processing unit from the measurement signals of the two temperature sensor and the output signal of the sensor is representative of the interior temperature Output signal determined.

In particular, comes as a temperature sensor NTC resistance element in question, which is expediently in the form of an SMD component is present. Alternatively come to an NTC resistance element a PTC resistance element or a thermocouple, in each case expediently also in SMD component version in Question. The sun sensor is preferably a photodiode. Both components are one at the front ends of three so-called three-pin standard leadframe Arranged connecting elements that extend close to an outer surface of the housing. The middle of the leads to three final elements one for the temperature sensor and the sun sensor common electrical potential, is so each with an electrical connection of temperature sensor and Sun sensor connected while the other two connection elements with the other electrical connections of temperature sensor and sun sensor are connected.

For design reasons, a material is used for the housing dark or black material used. As a result, the housing can be optically can be arranged in a noticeable manner in a boundary wall of the room.

In the case of using the device according to the invention for the Interior temperature measurement of vehicles equipped with air conditioning systems you become the housing in an opening a front panel adjacent to the interior of the vehicle Air controller accommodate.

In addition to the measurement technology described above Detection of thermal influences (by a further temperature sensor as described above) this can thermal influences additionally or alternatively also on the basis of calculation models or on the basis of operating parameters of the adjacent vehicle components or components can be determined. From these operating parameters then self-heating determine mathematically. Are responsible for such self-heating especially light sources that the vehicle component (climate control unit) for backlighting a front panel, a display or the like. having. If the operating voltage this possibly dimmable backlighting is used as a basis the expected self-heating can be concluded (calculation model).

In an advantageous development of the invention, it is further provided that the processing unit has a differentiating element with a time constant for long-term differentiation of the measurement signal from the temperature sensor. The constant or advantageously also changeable time constant of the differentiating element is preferably between a few minutes and a few 10 minutes (for example 10 to 30 minutes) and in particular between 2 minutes and 15 minutes. According to the invention, the measurement signal of the temperature sensor and the differentiated measurement signal, ie the output signal of the differentiating element, are added in the processing unit. The addition of both signals represents the temperature in the passenger compartment of the vehicle. As a result, the thermal inertia of the components surrounding the temperature sensor or the like. be compensated. Instead of differentiating the output signal of the temperature sensor, the difference between the setpoint and the actual value of the interior temperature can also be differentiated. To this extent, the term "processing unit" is used in the context of this description of the invention Exercise can also be understood, for example, the interior temperature controller of a vehicle air conditioning system. The "measurement signal of the temperature sensor" also means the control deviation of the control loop.

In an advantageous development of the Invention is in the processing unit next to the differentiator also a reinforcing link with a gain factor arranged. This reinforcing member reinforced the differentiated measurement signal, i.e. the output signal of the differentiator. Conveniently, becomes the time constant of the differentiator and / or the gain factor of the reinforcing member kept constant or changed. The change is particularly dependent the possibly compensated measurement signal from the temperature sensor itself, the service life and / or the ambient temperature of the vehicle, the Deviation between the actual and the target value of the passenger compartment temperature or between the actual and the setpoint of the temperature in the passenger compartment incoming Air and / or the cooling water temperature.

• – Die Integration des SMD-Bauteils als Temperaturfühler und des Sonnensensors in ein gemeinsames Gehäuses. Es ergibt sich somit ein Bauteil mit zwei Funktionen (Temperaturmessung und Messung der Sonneneinstrahlung).
• – Die Anordnung des Sensors in eine den Innenraum eines Fahrzeugs begrenzenden Wand in der Form, dass der Temperaturfühler über die Oberfläche des Sensors unmittelbaren Kontakt mit der Temperatur der Innenraumluft an der den Innenraum begrenzenden Wand hat.
• – Die Anordnung des Temperaturfühlers in das Gehäuse des Sensors in unmittelbarer Nachbarschaft zur Oberfläche des Sensorgehäuses, durch die der Sonnensensor die Sonneneinstrahlung misst und die in Kontakt mit der Innenraumluft steht.
• – Eine direkte thermische Kopplung zwischen der Innenraumluft an der Oberfläche der Wand und dem Temperaturfühler durch das Gehäusematerial des Sensors. Dadurch entfällt ein Wärmeleitungselement zwischen Innenraum und Temperaturfühler.
• – Ein sehr kurzes Ansprechverhalten des Temperaturfühlers auf Temperaturänderungen der Innenraumluft, da eine direkte thermische Kopplung zwischen Innenraumluft und Temperaturfühler über die Oberfläche des Sensorgehäuses besteht. Der Temperaturfühler reagiert deshalb schnell und genau auf Temperaturänderungen der Innenraumluft.
• – Eine geringe Abweichung der durch den Temperaturfühler gemessenen Temperatur von der Temperatur der Innenraumluft an der begrenzenden Wand auf Grund der sehr guten thermischen Kopplung zwischen Innenraumluft und Temperaturfühler.
• – Ein geringer Einfluss von den Temperaturfühler umgebenden störenden Wärmequellen (Steuergerätebeleuchtung, Leistungsbauteile und andere Wärmequellen, z.B. eines Steuergerätes, in das der Sensor eingebaut ist, aber auch externe Geräte in Nachbarschaft zum Einbauort des Sensors), da über das schlecht wärmeleitende Leadframe die Wärme der thermischen Störquellen nur sehr schlecht auf den Temperaturfühler übertragen wird.
• – Ein geringer Korrektureinfluss des Differenziergliedes der Verarbeitungseinheit auf Grund der kurzen Ansprechzeit des Sensors und des oben beschriebenen geringen Einflusses störender Wärmequellen auf den Temperatursensor. Die Zeitkonstante des Differenziergliedes kann deshalb klein gewählt werden, so dass eine zeitlich genau aufgelöste Temperaturmessung der Innenraumtemperatur möglich ist. Ebenfalls kann der Verstärkungsfaktor des Differenziergliedes klein gewählt werden, so dass die Bestimmung der tatsächlichen Innenraumtemperatur verbessert wird.

The essential properties and advantages of the device according to the invention are:

• - The integration of the SMD component as a temperature sensor and the sun sensor in a common housing. The result is a component with two functions (temperature measurement and measurement of solar radiation).
• The arrangement of the sensor in a wall delimiting the interior of a vehicle in such a way that the temperature sensor has direct contact with the temperature of the interior air on the wall delimiting the interior via the surface of the sensor.
• - The arrangement of the temperature sensor in the housing of the sensor in the immediate vicinity of the surface of the sensor housing, through which the sun sensor measures the solar radiation and which is in contact with the indoor air.
• - A direct thermal coupling between the indoor air on the surface of the wall and the temperature sensor through the housing material of the sensor. This eliminates a heat conduction element between the interior and the temperature sensor.
• - A very short response behavior of the temperature sensor to temperature changes in the indoor air, since there is a direct thermal coupling between the indoor air and the temperature sensor via the surface of the sensor housing. The temperature sensor therefore reacts quickly and precisely to changes in the temperature of the indoor air.
• - A slight deviation of the temperature measured by the temperature sensor from the temperature of the indoor air on the delimiting wall due to the very good thermal coupling between the indoor air and the temperature sensor.
• - A slight influence from the disturbing heat sources surrounding the temperature sensor (control unit lighting, power components and other heat sources, e.g. a control unit in which the sensor is installed, but also external devices in the vicinity of the installation location of the sensor), because the heat of the thermal interference is transmitted very poorly to the temperature sensor.
• - A slight correction influence of the differentiating element of the processing unit due to the short response time of the sensor and the small influence of disturbing heat sources on the temperature sensor described above. The time constant of the differentiating element can therefore be chosen to be small, so that a temperature measurement of the interior temperature that is precisely resolved in time is possible. The gain factor of the differentiating element can also be chosen to be small, so that the determination of the actual interior temperature is improved.

The invention is described below closer to the drawing explained. In detail show:

1 a view from a vehicle interior onto the instrument panel,

2 a section along the line II-II of 1 to clarify the arrangement of the sensors for indoor temperature measurement with a non-ventilated sensor,

3 a section along the line III-III through the front panel and the components of the air conditioning control unit arranged behind this to illustrate the formation of the sensors and

4 a block diagram of the wiring of the non-ventilated temperature sensor to determine the temperature in the vehicle interior.

1 shows a view of the front of a passenger compartment arranged in the direction of travel 10 of a vehicle 12 , which has air conditioning (automatic climate control). In the instrument panel 14 of the vehicle 12 the air conditioning control unit is located 16 which is a front panel 18 with a display 20 as well as a variety of buttons 22 having. According to 2 closes the front panel 18 the control unit 16 to the interior 10 down. The control unit 16 has a housing 24 on that in the instrument panel 14 is let in. In addition to various sensors such as outside temperature sensors 26 and sun sensor 28 instructs the air conditioning system of the vehicle 12 a large number of components, which should not be dealt with at this point, since they are no longer relevant to the invention.

For the invention, however, the way of determining the temperature in the passenger compartment 10 , To determine this interior temperature, an arrangement of sensors is provided, the two temperature sensors 30 . 32 as well as a sun sensor 34 (Photodiode). The first temperature sensor 30 and the sun sensor 34 are in a common housing 36 arranged, in the material of this housing 36 embedded. This housing 36 is in an opening 38 the front panel 18 and stands at its front end 40 in which the first temperature sensor 30 and the sun sensor 34 are arranged on the front panel 18 in front. The first temperature sensor thus detects 30 the temperature of the air in a measuring range 42 around the front end 40 of the housing 36 , The second temperature sensor 32 is inside the case 24 of the control unit 16 arranged and measures the self-heating of the control unit 16 , This can be done as a result of the self-heating of the control unit 16 possibly distorted measurement signal of the first temperature sensor 30 compensate. The sun sensor 34 measures the intensity of the in the measuring range 42 incident solar radiation, so that its output signal heating the front panel 18 represented as a result of solar radiation. This in turn makes it possible to falsify the measurement signal of the first temperature sensor 30 due to the thermal influence of the front panel heated by solar radiation 18 to compensate.

As with 3 can be seen, protrude to the rear of the front panel 18 out of the housing 36 three connection elements 44 . 46 . 48 out that in the material of the case 36 are embedded. The front ends of these connection elements are in the immediate vicinity behind the end face 50 at the front end 40 of the housing 36 , At these ends of the connection elements 44 to 48 there is an NTC resistor element designed as an SMD component 52 as the first temperature sensor 30 and a semiconductor photodiode 54 with light incidence surface 55 as a sun sensor 34 , The middle connector 46 is electrically connected to both of these components, while the other connection ends of these components are electrically connected to the other two connection elements 44 and 48 are connected. As a result, there is the NTC resistance element 52 and the semiconductor photodiode 54 immediately behind the front 50 of the housing 36 , causing the NTC resistance element 52 the temperature of the air in the measuring range 42 recorded almost directly.

As already explained, the sun sensor serves 34 for recording incident radiation intensity in order to determine the surface heating as a result of the incident radiation. According to the known cosine law (also called lambent law), the radiation intensity striking a surface depends on the orientation of the surface element to the radiation direction, that is to say on the radiation incidence angle. Because of the light incidence surface 55 of the sun sensor 34 of (plastic) material of the housing 36 is covered, it is no longer possible to draw conclusions about the angle of incidence of the radiation from the measurement signal of the radiation intensity of the sensor. Especially when the angle of incidence is close to 90 ° to the perpendicular of the light incidence surface 55 of the sun sensor 34 its measurement signal is no longer representative of the angle of incidence.

According to the invention, this is due to the special design of the end face 50 of the housing 36 compensated. This face 50 has an outer ring area 49 which has a comparatively small radius of curvature and a circular inner region 51 encloses, whose radius of curvature is substantially larger than the radius of curvature in the outer ring region 49 and is more than 10.0 mm, preferably more than 30.0 mm.

The two sub-areas mentioned above 49 and 51 the front 50 are continuously differentiable.

The previously mentioned radii of curvature apply in this embodiment for one Standard LED package form (wired) with a diameter of approx. 5.0 mm and an axial Extent from 3.0 to 10.0 mm.

The installation height of the sun sensor is also important 34 and the distance of the light incidence surface 55 from the front 50 of the housing 36 , which in this embodiment is approximately 1.0 mm.

The NTC resistance element is so that the sun sensor can detect incident radiation from all solid angles 52 related to the front 50 of the housing opposite the sun sensor 50 arranged set back. During the sun sensor 50 on the front of the middle connection element 46 is arranged, the NTC resistance element is located 52 on the side surfaces of the connection elements 46 and 48 ,

To suppress thermal influences due to heat flow from the housing 24 of the air conditioning control unit 16 about the connection elements 48 and 46 they are made of a relatively poorly heat-conducting material, for example steel. The three connection elements 44 to 48 are through a behind the front panel 18 in the housing 24 of the air conditioning control unit arranged circuit board 56 passed through and electrically connected (not shown conductor tracks). On the circuit board 56 In addition to a large number of electrical and electronic components, there is also a processing unit 58 which, among other things, with the first temperature sensor 30 and the sun sensor 34 and on the other hand with the second temperature sensor 32 is electrically connected. The processing unit 58 receives the measurement signals from these sensors or sensors and processes them into a signal that shows the air temperature in the measuring range 42 or in the interior of the vehicle represents.

In 3 an alternate location of the NTC resistor element is shown in dashed lines 52 inside the case 36 shown. Basically, however, the measurement of the first temperature sensor applies 30 The further the first temperature sensor, the more accurate and undistorted 30 to the front end 40 of the housing 36 is arranged.

• – Als (erster) Temperaturfühler 30 wird ein SMD-Bauteil (NTC-Widerstandselement 52) verwendet.
• – Zur Messung des Sonneneinflusses wird ein Sonnensensor 34 in Form einer Fotodiode 54 verwendet.
• – Zur elektrischen Kontaktierung des ersten Temperaturfühlers 30 und des Sonnensensors 34 werden Anschlüsse in Form eines Drei-Pin Standard-Leadframes für bedrahtete Bauelemente eingesetzt. Als elektrisch leitendes Material für den Leadframe wird ein schlecht wärmeleitendes Material, beispielsweise Stahl, oder andere schlecht wärmeleitende Metalle verwendet. Durch eine entsprechende Ausgestaltung der Anschlusselemente 44 bis 48 lässt sich auch konstruktionsbedingt eine Wärmeentkopplung realisieren.
• – Das Gehäuse 36 liegt in Form eines im wesentlichen üblichen Fotodiodengehäuses zur Integration des ersten Temperaturfühlers 30 und des Sonnensensors 34 vor. Aber auch jede andere Gehäuseform ist möglich. Der Temperaturfühler 30 ist zweckmäßigerweise unmittelbar hinter der an den Innenraum angrenzenden Oberfläche (Stirnseite 50) angeordnet.
• – Die Oberfläche des Gehäuses 36 ist so gestaltet, dass der Einfluss der Sonneneinstrahlung auf die Temperaturerhöhung der Oberfläche in der Nähe des Gehäuses und im Gehäuse selbst durch den Sonnensensor (indirekt) korrekt ermittelt werden kann.
• – Bei dem Material, aus dem das Gehäuse 36 besteht, handelt es sich um ein Kunststoffmaterial, das optisch durchlässig ist und den Sonnensensor 34 sowie den ersten Temperaturfühler 30 vor mechanischen Einflüssen schützt. Weiterhin bietet das Gehäuse 36 durch eine entsprechende konstruktive Gestaltung die Möglichkeit der Befestigung in oder an einem Objekt, vorzugsweise an der Frontblende 18 oder der Leiterplatine 56 des Klimaanlagen-Steuergeräts 16.
• – Auf Grund der optischen Durchlässigkeit des Materials des Gehäuses 36 können Störeinflüsse auf das Messsignal des ersten Temperaturfühlers 30 auf Grund der Sonneneinstrahlung in Abhängigkeit sowohl vom Einfallswinkel als auch von der Intensität der Sonnenstrahlung erfasst werden.

The peculiarities and components of the previously described and in particular in 3 The combined temperature and sun sensors shown can be briefly summarized as follows:

• - As the (first) temperature sensor 30 becomes an SMD component (NTC resistance element 52 ) used.
• - A sun sensor is used to measure the influence of the sun 34 in the form of a photodiode 54 used.
• - For electrical contacting of the first temperature sensor 30 and the sun sensor 34 connectors in the form of a three-pin standard leadframe are used for wired components. A poorly heat-conducting material, for example steel, or other poorly heat-conducting metals is used as the electrically conductive material for the leadframe. By designing the connection elements accordingly 44 to 48 thermal decoupling can also be achieved due to the design.
• - The housing 36 is in the form of an essentially conventional photodiode housing for integrating the first temperature sensor 30 and the sun sensor 34 in front. But any other housing shape is also possible. The temperature sensor 30 is expediently directly behind the surface adjacent to the interior (end face 50 ) arranged.
• - The surface of the case 36 is designed so that the influence of solar radiation on the temperature increase of the surface near the housing and in the housing itself can be correctly (indirectly) determined by the sun sensor.
• - The material from which the housing 36 there is a plastic material that is optically transparent and the sun sensor 34 as well as the first temperature sensor 30 protects against mechanical influences. The case also offers 36 by means of an appropriate structural design, the possibility of fastening in or on an object, preferably on the front panel 18 or the printed circuit board 56 of the air conditioning control unit 16 ,
• - Due to the optical permeability of the material of the housing 36 can influence the measurement signal of the first temperature sensor 30 due to the solar radiation depending on both the angle of incidence and the intensity of the solar radiation.

All measuring sensors (temperature sensors 30 . 32 and sun sensors 28 . 34 ) are according to 4 interconnected with each other, based on their measurement signals to the temperature in the passenger compartment 10 to be able to close. 4 shows the block diagram of the processing unit 60 ,

The measurement signal of the temperature sensor located behind the front panel 30 is influenced by the control unit self-heating and the heating of the front panel 18 due to sun exposure. Therefore, the circuit according to 4 one unity 62 to compensate for device heating. The measurement signals of the two temperature sensors are in this unit 30 . 32 subtracted from each other and the difference signal a low-pass filter 64 fed. The output signal of the low pass filter 64 with the measurement signal of the temperature sensor 30 interconnected by forming the difference between the two.

The circuit according to 3 also has a unit 66 to compensate for the heating of the front panel 18 due to sun exposure. The one in the front panel 18 provided sun sensor 34 is, as described above, in the immediate vicinity of the temperature sensor 30 arranged. Basically, it is sufficient if only the output signal of the on the front panel 18 arranged sun sensor 34 is evaluated. However, in special situations, it can be useful by comparing the output signals from the air conditioning sun sensor 28 and the front panel sun sensor 34 the angle and intensity of the on the temperature sensor 30 to determine the exposure to solar radiation. Then namely the heating of the front panel 18 be determined more precisely by the sun. This applies in particular in cases where, due to space-related situations, the sun sensor is also on the side 34 Sun radiation acts. The output signal of the first (front panel) temperature sensor 30 becomes the output signal of the circuit component 68 to evaluate the unit's sun sensor signals 66 compensates for what happens through subtraction.

The measurement signal of the front panel temperature sensor 30 also during temperature transient processes for determining the temperature in the passenger compartment 10 To be able to use it as quickly as possible, it is necessary to subject this measurement signal to dynamic compensation, regardless of whether it is now, as described above, compensated or not. For this purpose the circuit is according to 4 with a dynamic compensation unit 70 Mistake. This unity 70 has a differentiator 72 and a reinforcing member 74 whose time constant τ and gain factor k can be changed. This change is dependent on the temperature-compensated measurement signal from the temperature sensor 30 from the outside temperature sensor 26 measured outside temperature, the service life of the vehicle and the difference ε between the target value and the actual value of the temperature in the passenger compartment 10 , With the differentiator 72 is a long-term differentiator whose time constant is in the range from a few minutes to a few 10 minutes. By differentiating the measured or precompensated signal from the temperature sensor 30 incorrect measurements are compensated. The entire to the passenger compartment 10 Adjacent vehicle area namely heats up much more slowly or cools down much more slowly than the air in the passenger compartment 10 , This must be done when measuring the temperature in the passenger compartment using the near the front panel 18 arranged temperature sensor 30 be taken into account what by the long-term differentiator 72 he follows. About the reinforcing link 74 and in particular via a change in its gain factor, a weighting of these influencing factors on the measurement signal of the temperature sensor 30 be made.

Overall, the wiring results in accordance with 4 and in particular with the long-term differentiation of the dynamic compensation unit 70 a comfortable device for determining the temperature inside a vehicle without using a ventilated interior temperature sensor. The advantages of the "non-ventilated" temperature sensor used according to the invention can be seen in an increase in the reliability of the entire device, since there is no fear of electrical and mechanical failures of movable components. In addition, there is a cost saving as well as an increased functionality and a comfort advantage since the danger of acoustic annoyance is excluded.

The peculiarities of the optical Sensors for the detection of incident radiation intensity Determination of the surface heating by the Radiation incidence were determined in the context of this description using the For example, the integration in a temperature measurement Sensor described. The invention is based on the combination of optical sensor with a temperature sensor and not limited can also be used without the sun sensor casing a temperature sensor is housed. Integration of the temperature sensor in the housing has the main advantage that then with one and the same Element (housing) both the temperature and the radiation can be detected.

10

passenger compartment

12

vehicle

14

dashboard

16

control unit

18

front panel

20

display

22

Keys

24

casing

26

Outdoor temperature sensor

28

Air conditioning sun sensor

30

Interior temperature sensor,

32

temperature sensor

34

Front panel sun sensor

36

casing

38

opening

40

front end of housing 36

42

measuring range

44

connecting element

46

connecting element

48

connecting element

50

Front of housing 36

52

NTC resistor element

54

photodiode

55

Light incidence areas of the photodiode

56

printed circuit board

58

processing unit

60

processing unit

62

compensation unit

64

Low Pass Filter

66

compensation unit

68

circuit component

70

Dynamic compensation unit

72

Long Tent differentiator

74

reinforcing member

Claims (15)

Device for determining the temperature in a room with a boundary wall that is at least partially permeable to solar radiation, in particular in the interior of a vehicle, with a first temperature sensor ( 30 ) to record the temperature in the first temperature sensor ( 30 ) surrounding or adjacent measuring range ( 40 ) of the room ( 10 ), - a sun sensor ( 34 ) with a light incidence surface ( 55 ) to determine the solar radiation, the measuring range ( 40 ) of the room ( 10 ) is exposed, - whereby the first temperature sensor ( 30 ) and the sun sensor ( 34 ) in a common housing ( 36 ) are arranged, from which the first temperature sensor ( 30 ) and the sun sensor ( 34 ) connected connection elements ( 44 . 46 . 48 ) are brought out, and - a processing unit ( 58 ), the measurement signals from the first temperature sensor ( 30 ) and the sun sensor ( 34 ) and the temperature in the measuring range ( 40 ) and / or space ( 10 ) represent outputs the output signal, characterized in that - the first temperature sensor ( 30 ) and the sun sensor ( 34 ) in the housing ( 36 ) forming material are embedded - that the light incidence surface ( 55 ) of the sun sensor ( 34 ) to the measuring range ( 40 ) of the room ( 10 ) adjacent outer face ( 50 ) of the housing ( 36 ) indicates that - the front outer surface ( 50 ) has a first radius of curvature in an annular outer region and a second radius of curvature in a circular inner region surrounded by the outer region, which radius is substantially larger than the first radius of curvature, and - that the first radius of curvature is approximately 1/5 of the diameter of the end-face outer surface or 0.5 to 1.5 mm and the second radius of curvature is at least 10 times the first radius of curvature. Device according to claim 1, characterized in that the distance between the light incident surface ( 55 ) of the sun sensor ( 34 ) from the outer surface ( 5 ) of the housing ( 36 ) is approximately 1.0 mm. Device according to claim 1 or 2, characterized in that the first temperature sensor ( 30 ) immediately behind an outside surface ( 50 ) of the housing ( 36 ) is arranged. Device according to one of claims 1 to 3, characterized in that the electrical connection between the first temperature sensor ( 30 ) and the processing unit ( 60 ) and especially those with the first temperature sensor ( 30 ) connected connection elements ( 46 . 48 ) are thermally decoupled to reduce thermal influences. Device according to one of claims 1 to 4, characterized in that the with the first temperature sensor ( 30 ) connected connection elements ( 46 . 48 ) has a poorly heat-conducting, electrically conductive material. Device according to one of claims 1 to 5, characterized in that a further temperature sensor ( 32 ) for determining temperature influences on the housing ( 36 ) adjacent areas and / or components on the first temperature sensor ( 30 ) is provided and that the additional temperature sensor ( 32 ) with the processing unit ( 60 ) connected is. Device according to one of claims 1 to 6, characterized in that the first temperature sensor ( 30 ) an NTC or PTC resistance element ( 52 ) or a thermocouple, in particular in the form of an SMD component. Device according to one of claims 1 to 7, characterized in that the sun sensor ( 34 ) a photodiode ( 54 ) is. Device according to one of claims 1 to 8, characterized in that the housing ( 36 ) for arrangement in an opening ( 38 ) in one to the interior ( 10 ) of a vehicle’s front panel ( 18 ) an air conditioning control unit ( 16 ) is provided. Device according to one of claims 1 to 9, characterized in that in the processing unit ( 58 ) the influence of the temperature of a vehicle component arranged near the temperature sensor, in particular a control device ( 16 ) for a vehicle air conditioning system, can be corrected. Apparatus according to claim 10, characterized in that the temperature of the vehicle component directly by a further temperature sensor ( 32 ) can be determined metrologically and / or indirectly as a result of the current operating state of the vehicle component. Apparatus according to claim 11, characterized in that the vehicle component has front-side backlighting and / or an illuminated display ( 20 ) and that the control voltages for the backlighting and / or display lighting are used for the indirect detection of the temperature of the vehicle component. Device according to one of claims 1 to 12, characterized in that the processing unit ( 58 ) a differentiator ( 72 ) with a time constant (τ) for long-term differentiation of the measurement signal and / or the possibly corrected measurement signal of the temperature sensor ( 30 ), the processing unit ( 58 ) the measurement signal or the corrected measurement signal and the differentiated measurement signal added, and that the addition of these two signals the temperature in the interior ( 10 ) represents the vehicle. Device according to one of claims 1 to 13, characterized in that the processing unit ( 58 ) a reinforcing member ( 74 ) with an amplification factor for amplifying the possibly differentiated and / or corrected measurement signal of the temperature sensor ( 30 ) having. Device according to claim 13 or 14, characterized in that the. Time constant (τ) of the differentiator ( 72 ) and / or the gain factor (k) of the reinforcing element ( 74 ) depending on the possibly corrected measurement signal of the temperature sensor ( 30 ), the service life of the vehicle, the ambient temperature of the Vehicle, the deviation between the actual and the target value of the vehicle interior temperature or the temperature of the vehicle interior ( 10 ) inflowing air and / or the cooling water temperature can be selected and / or corrected.