Sensor device and method for protecting a sensor device

Abstract

A sensor device with an electromagnetic spectral sensor and at least one protection device, wherein the electromagnetic spectral sensor is associated with a transmission surface which is formed and arranged to transmit electromagnetic radiation, wherein the protection device has a gas guide which has at least one nozzle, and wherein the nozzle has a nozzle outlet in the region of the transmission surface. In order to enable safe operation of the sensor device, in particular when used in a detection system of a vehicle it is provided that a supplementary fluid, which is different from the working gas, is at least temporarily admixed to at least part of the working gas by means of a mixing arrangement.

Description

DESCRIPTIONSENSOR DEVICE AND METHOD FOR PROTECTING A SENSOR DEVICETECHNICAL FIELD

[0001] The invention relates to a sensor device with an electromagnetic spectral sensor and at least one protection device, wherein the electromagnetic spectral sensor is associated with a transmission surface which is formed and arranged to transmit electromagnetic radiation, wherein the cleaning device has a at least one nozzle, and wherein the nozzle has a nozzle outlet in the region of the transmission surface.BACKGROUND ART

[0002] In modern vehicles, optical sensor devices are increasingly used to observe the surroundings. Cameras, lidar sensors, and other optical sensors are frequently used. The relevance of these sensors is particularly high in autonomous vehicles. A basic requirement for the safe operation of the vehicle is the proper function of the sensors for orientation in space. Contamination of the sensor surface, caused for example by collisions with dirt particles, water, or insects, is therefore contrary to the safe operation of the vehicle.

[0003] Various concepts are currently being pursued for cleaning the transparent light-emitting surface (transmission surface) of the sensor surface. In the known concepts, several cleaning nozzles are used to clean the sensor surface by directly applying gaseous or liquid media to remove the particles from the transparent light-emitting surface. In addition to cleaning via cleaning nozzles, mechanical cleaning of the surface by means of various wiping concepts in combination with liquid wetting are known.

[0004] Another known method is cleaning by ultrasound (~35Hz). In some cases, a liquid is first applied to the sensor surface. A piezo crystal then causes the sensor surface to vibrate, which loosens the contaminants.

[0005] In the known concepts, an attempt is made to clean the sensor surface as well as possible, or an attempt is made to prevent adhesion of particles. It is technically complex to ensure continuous and complete cleaning of the surface. For example, the maximum amount of liquid that can be carried in the vehicle is limited. This means that continuous cleaning cannot be guaranteed, or the cleaning fluid must be replaced frequently.

[0006] Another disadvantage is the number of components in the known concepts. In most cases, several cleaning nozzles are used per sensor, which must be connected to a compressed air system or liquid system via hoses. Due to the number of components, it is often not possible to implement a compact design. In addition, the costs and complexityincrease with the number of components. Also, these nozzles cannot protect the sensor, they can only provide cleaning.

[0007] In the known concepts with gaseous cleaning media, the sensor surface is cleaned via shear stresses.DISCLOSURE OF THE INVENTION

[0008] The objective of the invention is to create a sensor arrangement comprising a protection device for an electromagnetic spectral sensor, which enables safe operation of an object detection system. The device is applicable to mobile (such as vehicle), and immobile (such as defense / security) systems.

[0009] This task is solved by means of a sensor device according to the claims. Accordingly, it is provided that a supplementary fluid, which is different from the working gas, is introduced in the flow path. The supplementary fluid can be admixed to at least part of the working gas by means of a mixing arrangement.

[0010] With the working gas stream, the supplementary fluid can be conveyed in a common fluid flow to the transmission surface to be cleaned in order to remove impurities. For this purpose, the supplementary fluid can be suitably selected to enable effective cleaning. In a preferred embodiment, the invention enables different cleaning concepts, for example depending on the degree of contamination. For example, in a first mode, it is possible to deliver only the working gas to the transmission surface to perform suitable cleaning or protection. In a further mode, the fluid flow supplemented with the supplementary fluid can be directed onto the surface to support the cleaning effect of the cleaning gas. Then even stubborn contaminants can be removed.

[0011] The constructive outlay for an arrangement according to the invention is conceivably simple, since the two fluid streams are combined and guided in one flow. For this purpose, it can especially be provided, that the supplementary fluid is admixed to the working gas in the direction of flow upstream of the nozzle.

[0012] According to a preferred embodiment of the invention it can be provided that the gauge pressure in the gas conduit is in the range between >0 bar and 4 bar. In this gauge pressure range, a sufficient cleaning and / or protection effect is made possible, and at the same time, a sufficient pressure gauge pressure level is provided which allows transport of the supplementary fluid. It is particularly preferred that the gauge pressure is selected in the range between 1 bar and 2 bar. With such an arrangement, comparatively compact sensors, in particular lidar sensors, can be reliably cleaned and / or protected.

[0013] In a further embodiment of the invention, it can be provided, that the main flow direction of the flow emerging from the nozzle encloses an angle of attack in the range between ± 20° with the surface of the transmission surface.

[0014] For the purposes of the invention, a negative angle of attack means that the flow is directed towards the transmission surface. At 0°, the main flow direction is parallel to the transmission surface. When used for cleaning and / or protecting sensors, especially LIDAR sensors on motor vehicles, the angle of attack can preferably be selected in the range between 0° to -20°.

[0015] In a further preferred embodiment of the invention, an outlet region of the gas guide is provided which, at least in a partial region, follows the contour of the transmission surface. One nozzle is arranged in the outlet region, or a plurality of mutually spaced nozzles are provided. This supports a good cleaning / protection effect.

[0016] Here it can preferably be provided that the transmission surface is flat and the at least one cleaning nozzle follows the transmission surface with a straight nozzle outlet at least in a partial region.

[0017] In case it is provided, that the flow velocity of the fluid flow guided to increase, at least in partial regions, in the direction towards the nozzle or nozzles, then the kinetic energy of the fluid, preferably at the nozzle exit is increased to achieve a better cleaning / protection effect.

[0018] The flow speed out of the nozzle can be subsonic, sonic or supersonic i.e., the flow speed can be below, at, or above the speed of sound. The required speed is depending on the cleaning / protection requirement, the surrounding masking noise, and the customer requirements for the nozzle noise level.

[0019] In order to keep the design effort of a protection device according to the invention low, it can be provided that the gas guide has a distribution chamber to which at least one guide channels is connected by its channel inlet. Thus, no complex piping is necessary to be able to clean even larger transmission areas.

[0020] In case it is further provided, that the channel cross section of the guide channels decreases from the channel inlet in the direction of the channel outlet, at least in some regions, to increase the flow velocity and therefore the kinetic energy in the fluid flow.

[0021] In order to achieve a uniform flow distribution in the area of the inlet to the nozzle(s), it can be provided that at least some of the guide channels open with their channel outlets in the direction of flow upstream of the nozzle or nozzles into a collecting region.

[0022] However, it may additionally or alternatively be the case, that at least some of the guide channels open with their channel outlets directly into a nozzle inlet of at least one nozzle.

[0023] According to a preferred embodiment of the invention, it may be provided that the nozzle or at least one of the cleaning nozzles(s) has a nozzle inlet which is followed in the direction of flow by a transition section within which the flow cross section is reduced. In the transition section the flow speed can be increased according to the requirements of the application.

[0024] It may further be provided, that and in that the transition section is followed by a cross- sectional widening and a nozzle outlet adjoining the latter or that the nozzle outlet directly adjoins the transition section

[0025] With a constant area or convergent nozzle, a flow velocity up to the speed of sound can be achieved.

[0026] If the velocity is sufficient for the application, then the transition section can be followed directly by the nozzle exit, or the nozzle exit can be followed indirectly by the transition section, for example via a guide section where there is no change in cross-section.

[0027] If a supersonic flow speed is required, a convergent section followed directly or indirectly by a divergent section of the nozzle i.e., a Laval-Nozzle is required.

[0028] A possible variant of the invention may be that the protection device has a fluid supply reserve connected, such that there is no need to connect to an external supply. This creates a compact unit that can be easily installed to a sensor.

[0029] According to a further improved embodiment of the invention, it may be provided that the exit width of the cleaning / protection nozzle, measured perpendicularly to the transmission surface, is in the range between 0.1 mm to 20mm, and / or the exit cross-sectional area is between 0.01 mm2and 1000 mm2. Particularly for automotive applications, the preferable exit width is between 0.1 mm to 10mm, and / or the exit cross-sectional area is between 0.01 mm2and 100 mm2

[0030] In case it is provided that at least one nozzle is arranged at least in regions above the transmission surface in the direction of gravity, then gravity additionally supports the cleaning / protection effect. Alternatively, the nozzle can be placed to utilize the surrounding environment flow direction which might be against gravity, for example in the direction of the flow over the windshield.

[0031] It is advantageous if adhesion of dirt to the transmission surface is prevented to keep the cleaning / protection effort as low as possible. Thus, according to one variant of the invention, it may be provided that the transmission surface, or a region thereof, is coated with a coating, in particular with a hydrophobic coating.

[0032] According to an embodiment of the invention, it may be provided that a second nozzle arrangement is spaced to the first nozzle arrangement in the direction perpendicular to thetransmission surface to the first nozzle arrangement. The second nozzle arrangement generates a further gas flow, in particular a gas curtain, on the side facing away from the transmission surface upstream of the fluid flow of the protection device. This gas curtain prevents particles from hitting the transmission surface, so that the cleaning / protection effort is significantly reduced. Thus, for example, the gas curtain can be generated permanently. The protection device is only activated when this is necessary to clean the transmission surface. This allows the amount of cleaning / protection intervals to be increased and thus additionally reduces the amount of supplementary fluid required. The gas mass flow and velocity are modulated depending on the conditions and the requirements.

[0033] The object of the invention is also solved by a method. Thus according to the invention a method for cleaning a sensor device with an electromagnetic spectral sensor by means of at least one protection device is suggested, wherein the electromagnetic spectral sensor has a transmission surface which is designed and arranged to transmit electromagnetic radiation, wherein the protection device has a gas guide which has at least one nozzle, and wherein the nozzle has a nozzle outlet in the region of the transmission surface, for cleaning and / or protecting the transmission surface at least in regions. According to the invention it is provided , that a supplementary fluid, which is different from the working gas guided in the gas guide, is at least temporarily admixed to at least part of the working gas by means of a mixing arrangement.

[0034] A possible embodiment of the invention can be such that a detection device is provided which indirectly or directly detects or determines a contamination of the sensor or the pollution of the surrounding air. In particular, the degree of contamination, the state of contamination of the transmission surface, or the contamination of the surrounding environment may result in that a volumetric flow of the working gas is generated or intensified in the gas conduit when the detection device detects unacceptable contamination of the transmission surface. It may also result in that the supplementary fluid is admixed to a volumetric flow of the working gas in the mixing arrangement when the detection device detects impermissible contamination of the transmission surface. With such a method, preferably automated cleaning / protection can be carried out. If the volume flow of the working gas is not sufficient for cleaning / protection, the volume flow can, for example, be intensified, i.e., the mass flow rate and / or the speed of the volume flow can be increased, in order to achieve a better cleaning / protection effect. In addition, or alternatively, the supplementary fluid can be mixed into the volume flow of the working gas if the cleaning / protection of the transmission surface can no longer be achieved with the volume flow of the working gas alone.

[0035] In case it is provided, that the fluid flow of the supplementary fluid is stopped, and the volume flow of the working gas is maintained at least for a time range or permanently, then any supplementary fluid remaining on the transmission surface can be cleaned off with the working gas. If the flow of the working gas is maintained permanently, a gas curtain can be created which at least impedes impurities from impinging on the transmission surface.

[0036] According to a further preferred embodiment of the invention, it can be provided that working gas mass flow and / or of the supplementary fluid is controlled as a function of ambient conditions, in particular the flow velocity of the ambient air, a measured volume, a degree of contamination of the ambient air and / or the humidity in the ambient air.

[0037] For example, it can be provided that the mass flow is reduced if the flow velocity in the environment is reduced due to a reduced driving speed of a vehicle. This takes into account the fact that reduced mass flow in the protection device is also accompanied by reduced noise emissions, so that no undesirable noise pollution occurs. Increasing the mass flow can also be advantageous if rain increases the obstruction of the transmission surface.

[0038] According to a preferred embodiment of the invention, turbulent flow at the transmission surface increases the shear of the fluid flow and thus the cleaning power. A Reynolds number > 3x105is taken as a metric to define successful turbulent flow in at least subregions of the transmission surface. In order to increase the turbulence intensity, it may be provided that the transmission surface comprises surface structures. For example, trip wires, surface depressions, surface indentations, surface elevations and / or surface roughness can be used on the transfer surface.

[0039] According to the invention, any fluid can be added to the working gas. In preferred embodiments of the invention, it can be provided that a liquid, a gas, a gas mixture, a mixture of a liquid with at least one gas, a mixture of a solvent with at least one gas, a solid stream with a maximum particle size preferably< 0.1mm, or a mixture of at least two of the aforementioned fluid streams is used as the supplementary fluid.

[0040] The invention is explained in more detail below with reference to examples of embodiments shown in the drawings. It shows:BRIEF DESCRIPTION OF THE DRAWINGS:

[0041] Figure 1 in schematic view a sensor device with a protection device,

[0042] Figure 2 a further sensor device with a protection device,

[0043] Figure 3 a design variant of a protection device in perspective view, whereby the hidden edges present in the interior of the protection device have been made visible,

[0044] Figure 4 a horizontal section through the arrangement according to Figure 3,

[0045] Figure 5 a front view of the arrangement according to Figures 3 and 4,

[0046] Figure 6 a side view of the arrangement according to Figures 3-5,

[0047] Figure 7 a detail of the protection device according to Figures 3-6 in schematic representation and side view,

[0048] Figure 8 an alternative to the detail shown in Figure 7,

[0049] Figure 9 an alternative of a protection device in perspective view, whereby the hidden edges present inside the protection device have been indicated,

[0050] Figure 10 a horizontal section through the protection device according to Figure 9 and

[0051] Figure 11 a further design variant of the invention in a partial representation.BEST MODE FOR CARRYING OUT THE INVENTION

[0052] Figure 1 shows a sensor device 10 with an electromagnetic spectral sensor 10.1 , for example a lidar sensor, which is arranged behind a transmission surface 11. The transmission surface 11 is formed as circumferential wall. The transmission surface 11 is such that it transmits electromagnetic radiation, for example light, microwaves, radar radiation or the like to and / or from the electromagnetic spectral sensor 10.1.

[0053] The sensor device 10 has a carrier 30 which is arranged on one side of the transmission surface 11. By means of the carrier 30, the sensor device 10 can be mounted at the desired location, for example on a motor vehicle.

[0054] Figure 1 shows that the sensor device 10 has a protection device 20. This can be assigned to the end of the transmission surface 11 , for example opposite the carrier 30.

[0055] In the present disclosure, spectral sensors can be LIDAR-sensors, video cameras, microwave sensors, radar sensors or the like.

[0056] A protection device according to the present disclosure is a device for cleaning and / or protecting the transmission surface of the sensor.

[0057] Figure 2 shows an alternative design variant of a sensor device 10 which has a circumferential transmission surface 11. The transmission surface 11 is not cylindrical, as shown in Figure 1, but rectangular and / or slightly curved. In all other respects, this sensor device 10 corresponds to the design shown in Figure 1.

[0058] Figure 3 shows a possible design variant of a protection device 20 for a sensor device 10. As the illustration shows, it can be the case that the protection device 20 has a head 21 to which a fluid supply 22 of a gas duct is connected. The fluid supply 22 may be such that it comprises at least one connector 22.1, 22.2 leading to a conduit region 22.3, 22.4. In the present embodiment example, two connection pieces 22.1, 22.2 are used, each with an associated conduit region 22.3, 22.4.

[0059] Feed lines can be connected to the connection pieces 22.1 , 22.2, as schematically illustrated in Figure 3. These feed lines come from a mixing arrangement 21 .8. A working gas G, for example ambient air, can be fed to the mixing arrangement 21.8 via a suitable line structure 21.10. The line structure 21.10 providing the working gas G may be referred to as a working gas source 21.10 configured to provide the working gas G. Furthermore, a supplementary fluid S is supplied permanently or temporarily to the mixing arrangement 21 .8 from a reservoir R via a fluid guide 21.9. The reservoir R and fluid guide 21.9 may be referred to as a supplementary fluid source configured to provide the supplementary fluid S different from the working gas G. The mixing arrangement 21.8 may also be described as being configured to at least temporarily mix the supplementary fluid S with the working gas G.

[0060] The two conduit regions 22.3, 22.4 open into a distribution chamber 21.1 of the head 21.

[0061] Starting from the distribution chamber 21.1 , supports 25 extend radially outward, with guide channels 26.2 of the fluid guide being formed between the supports 25. In the region of the distribution chamber 21.1 , the guide channels 26.2 have a channel inlet 26.1. At their radially outer ends, the guide channels 26.2 each have a channel outlet 26.3. It may be the case, as Figure 3 shows, that at least some of the channel outlets 26.3, in the present embodiment example all channel outlets 26.3, open into a collecting region 28 of the head 21.

[0062] Preferably, the free cross-section, of at least part of the guide channels 26.2 tapers from the channel inlet 26.1 towards the channel outlet 26.3. For example, as the present embodiments according to Figures 3 and 4 show, for this purpose the height h of the guide channels 26.2 continuously decreases in the direction towards the channel outlet 26.3.

[0063] As Figures 3 and 4 show, it may be the case that the width b of the guide channels 26.2 in the region of the channel inlet 26.1 is equal to or smaller than the width b in the region of the channel outlet 26.3. Nevertheless, the free cross-section in the guide channel 26.2 decreases due to the changing height h.

[0064] Figures 3 and 4 show that at least some of the guide channels 26.2 are laterally bounded by means of channel boundaries 21.3, preferably channel boundaries 21.3 of the supports 25 opposite each other. On their upper side, the guide channels 26.2 are delimited by a cover section 21.2, so that the guide channels 26.2 are open only in the region of their channel inlet 26.1 and their channel outlet 26.3.

[0065] As Figure 4 illustrates, a nozzle 27 is provided downstream of the collecting area 28. The nozzle 27 creates a connection between the collecting area 28 and the environment.

[0066] In the present embodiment example, the nozzle 27 is designed as an arcuate circumferential slot, in particular as a slot circumferentially arranged on an arc of a circle. It isalso conceivable that a plurality of nozzles 27 are arranged next to one another, which are formed in particular in the form of arcuately extending slots. In particular, the arcuate slots may be arranged on a common circular arc.

[0067] Preferably, the at least one arcuately circulating slot, follows the contour of the transmission surface 11 , at least in certain areas. In the present embodiment example, the nozzle 27 thus follows the contour of a cylindrical transmission surface 11 (see Figure 1), at least in partial regions.

[0068] An example of the geometric design of the at least one nozzle 27 is shown in Figures 5-6, and more clearly shown in Figure 7. As this illustration also shows, the guide channel 26.2 is limited on the cover side by means of the cover section 21 .2. The cover section 21.2 merges into an outer nozzle wall 21 .7 of the nozzle 27 via an inclined or preferably rounded transition region 21 .6. Preferably, the nozzle wall 21.7 is formed by an outer side wall 21 .4 of the head 21 to promote a compact design.

[0069] The nozzle 27 has a nozzle inlet 27.1 adjacent to the nozzle wall 27.1 , the nozzle inlet 27.1 merging into a nozzle outlet 27.3 via a transition portion 27.2.

[0070] As the illustration according to Figure 7 shows, it may be the case that the inner side of the transition section 27.2 is formed by a radially outer edge 24.1 of a cover 24. The cover 24 may be formed integrally with the head 21 . It is also conceivable that the cover 24 forms a separate component.

[0071] The radially outer wall of the transition section 27.2 can advantageously be formed by the side wall 21.4.

[0072] As Figure 7 illustrates, the nozzle outlet 27.3 results in an outlet surface adjacent the transmission surface 11 which, in the assembled state of the protection device 20, can advantageously be oriented perpendicular to the transmission surface 11 . Of course, it is also conceivable that the outlet surface is at an angle to the transmission surface 11. The nozzle outlet 27.3 may be described as being adjacent the transmission surface 11 or in the region of the transmission surface 11 when the nozzle outlet 27.3 is sufficiently close to the transmission surface 11 such that a stream of gas and / or supplementary fluid exiting the nozzle outlet 27.3 flows across the transmission surface 11 .

[0073] As illustrated in the drawing, the nozzle geometry of the nozzle 27 is selected such that a fluid flow exiting the nozzle 27 exits the nozzle outlet 27.3 with a main flow direction H. The main flow direction H includes a negative angle of attack a with the upper side of the transmission surface 11 , as illustrated in Figure 7.

[0074] Depending on the design of the nozzle geometry, in particular the transition section 27.2, the flow velocity of the fluid passing through the nozzle 27 can be influenced. In thepresent embodiment example, the transition section 27.2 has a continuously tapering geometry, at least in some regions, so that a fluid flowing through the nozzle 27 is accelerated. The resulting nozzle outlet 27.3 has the smallest cross-sectional area to increase fluid exit velocity and exit pressure.

[0075] Figure 8 shows an alternative embodiment of a nozzle 27. The design of this nozzle 27 corresponds essentially to the embodiment according to Figure 7, although a cross-sectional extension 27.4 adjoins the transition section 27.2. In the area of this cross-sectional expansion 27.4, the guided fluid flow can be expanded to allow a change in the flow velocity, in particular a further acceleration of the fluid flow into the supersonic range. In all other respects, reference can be made to the comments on Figure 7.

[0076] Figures 9 and 10 show a further design variant of a protection device 20. The technical design of this protection device 20 corresponds essentially to the design of the protection device 20 described above. In this respect, reference can be made to these explanations. Thus, only the differences will be explained in more detail below.

[0077] As Figures 9 and 10 show, the guide channels 26.2 are guided with their channel outlets 26.3 towards the nozzle inlet 27.1 of the nozzle 27, so that the guide channels 26.2 open directly into the nozzle 27. Here, as Figures 9 and 10 show, it is particularly the case that each guide channel 26.1 opens into its own nozzle 27, which is preferably slot-shaped.

[0078] The foregoing drawings illustrate that the protection device 20 is easy to handle as a compact structural unit and can be easily connected, by means of a fastening means 23, to the sensor device 10. As the illustrations show, the fastening means 23 may be formed as a slot-shaped aperture. The upper side 21.5 of the cover section 21.2 may be flat to save space.

[0079] In particular, it is possible to manufacture the protection devices 20 described above as a single part using a 3-D printing process. However, it is also conceivable that the protection devices 20 are manufactured in multiple parts, using either 3-D printing process or a plastic injection molding process.

[0080] Figure 11 illustrates a further design variant of a protection device 20. As can be seen from the schematic representation, this protection device 20 can be constructed in a substantially similar manner to the protection devices 20 according to Figures 3 to 10. Reference can thus be made to the above explanations. The protection device 20 has an arrangement with guide channels 26.2, which is guided towards one or more nozzles 27 (see above). Spaced in the direction perpendicular to the transmission surface 11 is a further nozzle arrangement 29 with at least one further nozzle forming an outlet opening 29.1. A gas flow, can be passed through the further nozzle arrangement 29 and blown out through the outletopening 29.1. In this way, a gas curtain is created in front of the transmission surface 11 , which prevents particles from impinging on the transmission surface 11.

[0081] In the following, the operation of the protection device 20 according to figures 3-10 will be explained in more detail.

[0082] As was described above, the protection device 20 forms a gas guide to which working gas G, for example ambient air, can be supplied. This working gas G is fed into the distribution chamber 21.1 via the connection pieces 22.1 , 22.2. From there, the working gas G enters the guide channels 26.2. It then flows out via the at least one nozzle 27. The working gas G then impinges on the transmission surface 11. Impurities adhering to the transmission surface 11 can be removed by the working gas G.

[0083] To support the cleaning and / or protection effect of the working gas G, a supplementary fluid S can be admixed in the mixing arrangement 21.8. Thus, a fluid stream is generated which is composed of working gas G and the supplementary fluid S. The fluid flow generated in this way can be fed back to the at least one nozzle 27 and directed to the transmission surface 11.

[0084] The admixture of the supplementary fluid S can take place either permanently or preferably temporarily on request of a control device.

Claims

ClaimsWhat is claimed is:1 . Sensor device (10) with an electromagnetic spectral sensor and at least one protection device (20), wherein the electromagnetic spectral sensor is associated with a transmission surface (11) which is formed and arranged to transmit electromagnetic radiation, wherein the protection device (20) has a gas guide which has at least one nozzle (27), and wherein the nozzle (27) has a nozzle outlet (27.3) in the region of the transmission surface (11) characterized in that a supplementary fluid (S), which is different from the working gas (G) guided in the gas guide, is at least temporarily admixed to at least part of the working gas (G) by means of a mixing arrangement (21.8).

2. Sensor device according to claim 1 , characterized in that the supplementary fluid (S) is admixed to the working gas (G) in the direction of flow upstream of the nozzle (27).

3. Sensor device according to claim 1 or 2, characterized in that the gauge pressure in the gas conduit is in the range between >0 bar and 4 bar, preferably in the range between 1 bar to 2 bar.

4. Sensor device according to any one of claims 1 to 3, characterized in that the main flow direction of the flow emerging from the nozzle (27) encloses an angle of attack (a) in the range between ± 20° with the surface of the transmission surface (11), it being preferably provided that the angle of attack (a) is selected in the range between 0° to -20°.

5. Sensor device according to any one of claims 1 to 4, characterized in that, downstream of the mixing arrangement (28) in the direction of flow, an outlet region of the gas guide is provided which, at least in a partial region, follows the contour of the transmission surface (11), and in that the one nozzle (27) is arranged in the outlet region or a plurality of mutually spaced nozzles (27) are provided.

6. Sensor device according to one of claims 1 to 5, characterized in that the flow velocity of the fluid flow guided in the gas guide increases at least in partial regions of the gas guide in the direction towards the nozzle or nozzles (27).

7. Sensor device according to claim 6, characterized in that the flow velocity of the fluid stream emerging from the nozzle (27) assumes a value smaller than or equal to the sound velocity or that the flow velocity of the fluid stream emerging from the nozzle (27) assumes a value greater than the sound velocity.

8. Sensor device according to one of claims 1 to 7, characterized in that the gas guide has a distributor chamber (21.1) to which a plurality of guide channels (26.2) is connected by their channel inlets (26.1), and in that the channel cross section of the guide channels (26.2)decreases from the channel inlet (26.1) in the direction of the channel outlet (26.3), at least in certain areas.

9. Sensor device according to one of the claims 1 to 8, characterized in that the nozzle (27) or at least one of the nozzles (27) has a nozzle inlet (27.1) which is followed in the direction of flow by a transition section (27.2) within which the flow cross section is reduced, in that the transition section (27.2) is followed by a cross-sectional widening (27.4) and a nozzle outlet (27.3) adjoining the latter or that the nozzle outlet (27.3) adjoins the transition section (27.2).

10. Sensor device according to one of claims 1 to 9, characterized in that the protection device (20) has a reservoir (R) in which the supplementary fluid (S) is stored, in that a fluid guide (21.9) is provided which connects the reservoir (R) to the mixing arrangement (21.8).

11. Sensor device according to any one of claims 1 to 10, characterized in that the protection device (20) has a head (21) to which a fluid supply (22) is connected, the fluid supply (22) having at least one conduit region (22, 23) with a connector (22.1 , 22.2) for conducting the fluid flow towards the head (21).

12. Sensor device according to one of the claims 1 to 11 , characterized in that the width of the nozzle(s), measured perpendicularly to the transmission surface, is in the range between 0.1mm to 20mm, preferably 0.1 mm to 10mm, and / or in that the cross-sectional area of the nozzle(s) (27) in the region of the nozzle outlet (27.3) is in the range between 0.01 mm2and 1000mm2, preferably in the range between >0.01 mm2and 100 mm2.

13. Sensor device according to one of claims 1 to 12, characterized in that the at least one nozzle (27) is arranged at least in regions above the transmission surface (11) in the direction of gravity or in that at least one nozzle (27) is placed at least in regions below the transmission surface (11) to utilize the surrounding flow direction which might be against gravity, e.g. in the direction of the flow over a windshield.

14. Sensor device according to one of claims 1 to 13, characterized in that the transmission surface (11) is coated at least in regions with a coating, in particular with a hydrophobic coating.

15. Sensor device according to one of claims 1 to 14, characterized in that an additional, adjacent nozzle arrangement (29) is arranged in the direction perpendicular to the transmission surface (11) upstream of at least one nozzle (27), which adjacent nozzle arrangement (29) generates an additional gas flow, in particular a gas curtain, on the side of the transmission surface (11).

16. Method for protecting a sensor device (10) with an electromagnetic spectral sensor by means of at least one protection device (20), wherein the electromagnetic spectral sensor is associated with a transmission surface (11) which is designed and arranged to transmit electromagnetic radiation, wherein the protection device (20) has a gas guide which has atleast one nozzle (27), and wherein the nozzle (27) has a nozzle outlet (27.3) in the region of the transmission surface (11), for protecting and / or cleaning the surface of the transmission surface at least in certain regions characterized in that a supplementary fluid (S), which is different from the working gas (G) guided in the gas guide, is at least temporarily admixed to at least part of the working gas (G) by means of a mixing arrangement (21.8).

17. Method according to claim 16, characterized in that a detection device is provided which indirectly or directly detects or determines a contamination of the sensor or contamination of the surrounding air, in particular the degree of contamination or the state of contamination of the transmission surface (11), and in that a volumetric flow of the working gas (G) is generated or intensified in the gas conduit when the detection device detects unacceptable contamination of the transmission surface (11) or the surrounding environment, and / or in that the supplementary fluid (S) is admixed to a volumetric flow of the working gas (G) in the mixing arrangement (28) when the detection device detects impermissible contamination of the transmission surface or the surrounding air (11).

18. Method according to claim 16 or 17, characterized in that, following a cleaning and / or protection process and / or when sufficient operability of the sensor device (10) is detected, that the volume flow of the working gas (G) and / or of the supplementary fluid is then reduced or stopped.

19. Method according to claim 18, characterized in that the fluid flow of the supplementary fluid (E) is stopped and the volume flow of the working gas (G) is maintained at least for a time range or permanently.

20. Method according to one of claims 16 to 19, characterized in that the volumetric flow of the working gas (G) and / or of the supplementary fluid (S) is controlled as a function of ambient conditions, in particular the flow velocity of the ambient air, a measured volume, a measured temperature, a degree of contamination of the ambient air, and / or the humidity in the ambient air.21 . Method according to one of claims 16 to 22, characterized, in that in order to increase the turbulence intensity, special measures can be employed for example trip wires, surface indentation or surface roughness.

22. Method according to one of claims 16 to 21 , characterized in that a liquid, in particular water, a gas, a gas mixture, a mixture of a liquid with at least one gas, a mixture of a solvent with at least one gas, a solid stream with a maximum particle size preferably <0.1 mm or a mixture of at least two of the aforementioned fluid streams is used as the supplementary fluid.

23. Method according to any one of claims 16 to 20 with a sensor device according to any one of claims 1 to 15.24: A sensor device, comprising: an electromagnetic spectral sensor; a transmission surface arranged to transmit electromagnetic radiation to and / or from the electromagnetic spectral sensor; a working gas source configured to provide a working gas; a supplementary fluid source configured to provide a supplementary fluid different from the working gas; a mixing arrangement configured to at least temporarily mix the supplementary fluid with the working gas; and a gas guide including at least one nozzle, the nozzle having a nozzle outlet adjacent the transmission surface.25: The sensor device of claim 24, wherein: the mixing arrangment is upstream of the nozzle with reference to a direction of flow of the working gas in the nozzle.26: The sensor device of claim 24, wherein: the working gas source is configured to provide the working gas to the gas guide at a pressure in a range of from 1 bar to 2 bar.27: The sensor device of claim 24, wherein: the nozzle is configured such that a main flow direction of working gas from the nozzle outlet encloses an angle of attack relative to the transmission surface in a range between 0° to - 20°.28: The sensor device of claim 24, wherein: the gas guide includes an outlet region downstream of the mixing arrangement, the outlet region at least partially following a contour of the transmission surface; and the at least one nozzle is arranged in the outlet region of the gas guide.29: The sensor device of claim 24, wherein: the gas guide is configured such that a flow velocity of working gas guided in the gas guide increases in a direction towards the at least one nozzle at least in partial regions of the gas guide. 30: The sensor device of claim 29, wherein: the gas guide is configured such that the flow velocity of working gas exiting the nozzle outlet is smaller than or equal to a velocity of sound.31 : The sensor device of claim 29, wherein:the gas guide is configured such that the flow velocity of working gas exiting the nozzle outlet is greater than a velocity of sound.32: The sensor device of claim 24, wherein: the gas guide includes a distributor channel and a plurality of guide channels, each of the guide channels including a guide channel inlet and a guide channel outlet, the guide channel inlet being connected to the distributor channel, wherein a channel cross section of each of the guide channels decreases from the channel inlet in a direction of the guide channel outlet at least in portions of the guide channel.33: The sensor device of claim 24, wherein: the nozzle includes a nozzle inlet followed in a direction of flow by a transition section in which flow cross section is reduced, and the transition section is followed by a cross-sectional widening, and the nozzle outlet adjoins the cross-sectional widening.34: The sensor device of claim 24, wherein: the nozzle includes a nozzle inlet followed in a direction of flow by a transition section in which flow cross section is reduced, and the nozzle outlet adjoins the transition section.35: The sensor device of claim 24, wherein: the supplementary fluid source includes a reservoir configured to store the supplementary fluid, and a fluid guide connecting the reservoir to the mixing arrangement.36: The sensor device of claim 24, wherein: the gas guide is defined in a head including at least one conduit connecting the gas guide to the working gas source.37: The sensor device of claim 24, wherein: the nozzle includes a width in a range form 0.1 mm to 10 mm measured perpendicular to the transition surface.38: The sensor device of claim 24, wherein: the nozzle outlet has a cross-sectional area in a range from 0.1 mm2to 100 mm2.39: The sensor device of claim 24, wherein: the at least one nozzle is arranged above the transmission surface relative to a direction of gravity.40: The sensor device of claim 24, wherein: at least a portion of the transmission surface is coated with a hydrophobic coating.41 : The sensor device of claim 24, further comprising: an additional nozzle arranged in a direction perpendicular to the transmission surface beyond the nozzle outlet of the at least one nozzle to provide a gas curtain along the transmission surface.42: A method of protecting a sensor device, the sensor device including an electromagnetic spectral sensor and a transmission surface arranged to transmit electromagnetic radiation, the sensor device further including a gas guide including at least one nozzle having a nozzle outlet adjacent the transmission surface, the method comprising: providing a stream of working gas through the gas guide and out the nozzle outlet to protect and / or clean at least a portion of the transmission surface; and at least temporarily admixing a supplementary fluid different from the working gas with the working gas.43: The method of claim 42, further comprising: detecting a degree of contamination of the transmission surface; and generating or intensifying a flow rate of the working gas through the nozzle outlet when an unacceptable degree of contamination of the transmission surface is detected.44: The method of claim 42, further comprising: detecting a degree of contamination of the transmission surface; and wherein the at least temporarily admixing the supplementary fluid different from the working gas with the working gas is performed when an unacceptable degree of contamination of the transmission surface is detected.45: The method of claim 44, further comprising: reducing or stopping the admixing of the supplementary fluid when the degree of contamination of the transmission surface is detected to again be acceptable.46: The method of claim 44, further comprising: stopping the admixing of the supplementary fluid when the degree of contamination of the transmission surface is detected to again be acceptable; and maintaining the flow of the working gas at least temporarily after stopping the admixing of the supplementary fluid.47: The method of claim 42, further comprising: controlling a flow rate of the stream of working gas through the gas guide and out the nozzle outlet and / or a flow rate of the supplementary fluid as a function of ambient conditions.48: The method of claim 42, wherein the supplementary fluid is selected from group consisting of: a liquid; water; a gas; a gas mixture; a mixture of a liquid with at least one gas;a mixture of a solvent with at least one gas; a solid stream with a maximum particle size of less than 0.1 mm; and a mixture of at least two of the above.

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