Optical monitoring system

Abstract

Rain and snow, as well as condensation on the glass, can impair vision through the protective panel.SOLUTION: The optical monitoring system serves to monitor the environment and has a monitoring device, the field of view or scanning field of which is captured by a lens, and a protective panel, which protects the lens from precipitation and covers at least the field of view or scanning field of the monitoring device. In order to prevent the signal quality of the monitoring device from being impaired by precipitation on the protective panel, it is proposed that the protective panel is acoustically coupled to the at least one ultrasonic transducer. The optical monitoring system comprises a temperature management system (2000) for monitoring the temperature of the transducer (10) and / or of the protective panel.SELECTED DRAWING: Figure 20

Description

[Technical Field]

[0001] According to the preamble of claim 1, the invention relates to an optical surveillance system comprising an optical surveillance device, the field of view or scanning field of which is captured by a lens, and a protective panel protecting the lens from precipitation and covering at least the field of view or scanning field of the surveillance device. [Background technology]

[0002] Optical surveillance devices have a very versatile field of use. Firstly, they can be implemented and used as stationary cameras, for example in the field of object surveillance, or as safety cameras in public spaces, or as cameras in vehicles, whose images and / or data signals serve to assist the driver or are evaluated and converted into control commands for the vehicle by a control system for the autonomous movement of a vehicle, which is also the subject of the present invention. Vehicles here should be understood to mean land vehicles, ships, and aircraft, with the autonomous driving of automobiles currently attracting a lot of attention.

[0003] Instead of a camera, other optical surveillance devices may have a laser scanner, an angled mirror (e.g., implemented as a periscope), or any other optical unit that focuses an image of the surrounding environment onto an eyepiece or an optical signal onto a sensor.

[0004] Regardless of use, a protective panel is provided to protect the sensitive lens, but the problem arises that the protective panel itself can be impaired in terms of visibility through the protective panel by precipitation, which is further understood to mean, inter alia, rain and snow as well as condensation on the glass. In the case of stationary monitoring devices, potentially important security information may not be captured or may only be captured too late. Precipitation further plays a detrimental role, for example, when monitoring the workspace of a machine tool where liquid media that can precipitate on the protective panel are used, or in humid ambient environments where condensation on the protective panel can be expected. The problem is particularly acute in the case of monitoring devices in vehicles, where information must be evaluated in real time to ensure safe control of the vehicle under all circumstances. Since the protective panels of the monitoring devices are particularly exposed to precipitation or the formation of ice, frost or condensation, it is essential to ensure clear visibility at least in the area of ​​the field of view or scanning field of the optical monitoring device so that the control system can rely on reliable information from the monitoring device at all times.

[0005] In the automotive field, arrangements of a forward-facing camera for evaluating the field of view ahead of a vehicle are known, such as behind a protective panel, for example, behind a transparent dome on the roof, behind a protective panel assigned to the camera, or behind the vehicle's windscreen. Conventional wipers can further clean the camera's field of view, but difficulties can arise in the case of partial formation of ice or condensed water within the camera's field of view, which the vehicle occupants do not even perceive when looking through their normal viewing window in the windscreen. Wiper / water-washing systems are also known in the case of transparent bell-shaped covers, in which a circumferential wiper sweeps the bell all the way around and cleans it, and water is sprayed onto the protective bell for assistance, possibly with detergent added to the water. The same problem occurs in the case of laser scanners, whose scanning field must likewise not be deteriorated by dirt. Summary of the Invention

[0006] The object of the invention consists in developing an optical monitoring device, the monitoring function of which is less deteriorated in the event of precipitation.

[0007] The main features of the invention are specified in the characterizing part of claim 1. Arrangements are the subject of claims 2 to 18. The subject of the invention further relates to a control system for controlling a vehicle according to claim 19.

[0008] According to the invention, an optical monitoring device of the type discussed in the introduction is provided with the technical innovation that the protective panel is acoustically coupled to at least one ultrasonic transducer.

[0009] It has been found that this arrangement makes it possible to achieve a particularly clear view through the protective panel particularly quickly, because the ultrasonic transducer, further called an ultrasonic probe, can be efficiently focused on the field of view or scanning field of the monitoring device on the protective panel, the size of which can vary depending on the focal length of the camera lens and its distance from the lens of the optical unit of the device, which in any case is smaller than the overall field of view of, for example, a vehicle windscreen, so that the cleaning effect can be optimized.

[0010] In the following, the objects to be cleaned, such as glass windows, glass panes of laminated glass, lenses of optical systems, protective or viewing panels or different surfaces, are combined under the term substrate, which means that the element to be cleaned has a transducer placed on its surface, i.e. the substrate is the substrate for the transducer.

[0011] The transducer may be a single element or may consist of a collection or array of elements that can be controlled by a synchronized signal to produce a uniform waveform. The array or collection may be controlled by slightly offset signals for each element of the array or collection to produce a particular waveform. The array or collection may be arranged on a substrate in a simple shape, such as a line, or in a complex shape, such as a polygon.

[0012] Space waves and / or surface waves can be generated by a transducer. For example, space waves can be longitudinal or transverse waves. Longitudinal waves vibrate in the direction of their longitudinal propagation. Transverse waves vibrate transversely to the direction of their transverse propagation. For example, surface waves are generated when space waves are refracted at an interface. Surface waves propagate perpendicular to the vibration direction of their surface waves along the interface between two acoustically different media. For example, Love waves vibrate horizontally at the interface and propagate perpendicular to the vibration direction. Rayleigh waves vibrate vertically relative to the interface and propagate perpendicular to the vibration direction along the interface. Surface waves encounter strong attenuation in each material across the interface. The sound waves generated by the transducer are preferably ultrasonic. Ultrasonic waves are a frequency range above the human audible frequency range, starting at approximately 16 kHz.

[0013] Generally, ultrasonic transducers are implemented as piezoelectric elements that are capable of producing ultrasonic waves with a desired frequency.

[0014] In a particularly preferred embodiment of the invention, the frequency range of at least one transducer is enabled to be between 0.5 and 5 MHz.

[0015] This embodiment not only allows the moisture adhering to the protective panel to be moved more quickly to the edge of the field of view, but also allows for the moisture to evaporate immediately by means of a possible high energy influx.

[0016] According to a further embodiment, the transducer can comprise a piezoelectric material, in particular lead zirconate titanate (PZT), with the resulting advantage that transducers with high frequency and power efficiency can thus be produced.

[0017] According to a further development, the transducer can optionally be provided with at least one electrode on the side facing the substrate or the protective panel. In this way, the ultrasonic energy emitted by the transducer can be advantageously coupled into the substrate. As a result of the preferred configuration, whereby the electrode is implemented in the direct vicinity of the surface of the substrate, certain wave types, for example surface waves or spatial waves, can be advantageously generated.

[0018] A further configuration allows the transducer to comprise at least one electrode group with at least one electrode in each case. In a further configuration, the transducer comprises at least two electrode groups with at least two electrodes in each case. In a further configuration, the transducer comprises at least three electrode groups with at least two electrodes in each case. Grouping the electrodes to form electrode groups allows the electrodes to be operated together. This results in reduced costs when integrating the transducer. If the connection of the electrodes to the electrode groups is optionally provided with respect to the transducer itself, a further advantage arises: separate power supply lines for the operation of the transducer are only required for the electrode groups, and not for the individual electrodes.

[0019] A development optionally allows the transducer to comprise a first group of electrodes and a second group of electrodes, the first group of electrodes comprising at least two electrodes with a first distance and the second group of electrodes comprising at least two electrodes with a second distance. As a result of two groups of electrodes with respective electrode distances being allowed, an advantage arises that different frequencies can be coupled into the substrate or into the protection panel by means of one transducer.

[0020] For practical purposes, a first electrode of a first electrode group may have a first dimension related to the dimension of the transducer, and a second electrode of a second electrode group may have a second dimension related to the dimension of the transducer, the first dimension being different from the second dimension. The electrodes, which may optionally be embodied as the shape of the transducer material, may have a length dimension and a width dimension. Furthermore, the electrodes may have a height related to the transducer material. The advantage resulting from this is that the electrodes can be designed taking into account the frequency to be generated by the electrode or electrode group. If a first dimension of the electrode is selected for the first electrode group, and said dimension is different from the second dimension of the second electrode of the second electrode group, different frequencies can be advantageously generated by means of the electrode group. A further advantage arising here is that, for example, the first frequency and the second frequency can be generated by only one transducer, the first frequency being also advantageously different from the second frequency, in particular higher than the second frequency. This can be particularly advantageous if there are different precipitation or contaminations on the substrate, which can either be moved or evaporated by means of different frequencies of sound waves coupled to the substrate by means of the transducer.

[0021] According to a further development, the first electrode group can be interdigitated with the second electrode group, in particular by an interdigital transducer. The advantage resulting from the interdigitated interdigitation is that surface waves can be generated by the transducer in a particularly effective manner.

[0022] According to the configuration, it is optionally possible for a first electrode group to be arranged in a first region of the transducer, and a second electrode group to be arranged in a second region of the transducer. As a result of this, possible interference in the generated waves can be advantageously weakened or avoided. Therefore, in a special configuration, it is possible for the first region and the second region to not overlap. In particular, the region does not need to be understood to mean a continuous region. Instead, the region is considered to be an area covered by another electrode group with the same characteristics. Thus, for example, it may be the case that the first region and the second region are arranged alternately in the longitudinal direction of the transducer.

[0023] The invention can be developed in that the transducer has a rectangular shape. As an alternative to the rectangular shape, the transducer may be L-shaped. A further alternative consists in the transducer being U-shaped. Finally, if the transducer is circular, this may be advantageous in terms of the transducer type configuration. Certain transducer types may be advantageous depending on the application. A rectangular or circular configuration of the transducer is particularly advantageous when the visual area of ​​the substrate or of the protective panel should not be substantially impaired. If precipitation is not only to be evaporated but also to be moved, it may be advantageous to configure the transducer to be L- or U-shaped. In this way, precipitation or contamination will spread in a preferred direction, especially in areas where the transducer material is not arranged on the substrate or protective panel.

[0024] It is advantageous if at least one transducer is arranged next to the field of view or scanning field of the monitoring device so as not to limit the field of view or scanning field, however, this does not always have to be the case, especially in the case of an arrangement of multiple monitoring devices, which may be a combination of scanners and cameras.

[0025] In a further preferred embodiment of the present invention, at least two transducers are allowed to be arranged around the periphery of the field of view or scanning field, which may also be advantageous if three or more transducers are arranged around the edge of the field of view or scanning field in a distributed manner.

[0026] By means of these measures it is possible to influence the distribution of ultrasound within the protective panel, in particular within the visual or scanning area, in a targeted manner in order to obtain homogeneous cleaning of the protective panel in the visual or scanning field of the monitoring device.

[0027] In addition to the number and location of transducers on the protective panel, a further option for influencing the distribution of ultrasonic waves consists of at least two transducers arranged offset from one another, the transducers emitting the same or different ultrasonic frequencies and / or the same or different ultrasonic waveforms to the protective panel. Therefore, the at least two transducers may operate at the same frequency or with the same waveform. Furthermore, a difference of a few Hz may be tolerated to overcome misalignment and the associated difference in the resonant frequency of the transducer-substrate-system. Additionally, the same or different ultrasonic frequencies may be a steady frequency or a frequency sweep. This has the added advantage that a single transducer setup can agitate a variety of different types of precipitation.

[0028] In a further configuration of the invention, the edge distance of the transducer may be selected depending on the working frequency range of the transducer in such a way that in the case where the surface wave is reflected at the edge of the substrate, constructive interference occurs.

[0029] The development optionally allows the working frequency range of the transducer to be selected depending on the edge distance of the transducer in such a way that constructive interference occurs between the surface wave emitted by the transducer and the surface wave reflected at the edge of the substrate.

[0030] Optionally, the working frequency range of the transducer can be selected depending on the thickness of the substrate such that constructive interference occurs within the substrate with spatial waves reflected at the edges or interfaces of the substrate.

[0031] For implementation purposes, the substrate thickness may be selected depending on the working frequency range of the transducer in such a way that constructive interference occurs within the substrate for spatial waves reflected at the edges or interfaces of the substrate.

[0032] Thus, the edge distance of the at least one transducer is optionally allowed to correspond to a fraction or multiple of the wavelength of the acoustic wave produced by the at least one transducer.

[0033] As a result of these developments in the utilization of constructive interference, wave energy that has not yet been transmitted to the precipitation for the purpose of evaporating or moving it, but that has been reflected at the boundaries of the substrate or protective panel, can be used even more advantageously without being lost due to the vibrations that are generated and that have not yet been reflected.

[0034] According to a development, it may be provided that the transducer is arranged in a gap between the two substrates.

[0035] Additionally, the transducer is optionally enabled to be located on a side of the substrate that is a distance away from the precipitation.

[0036] These advantageous configurations ensure that the transducer does not come into contact with precipitation, which further advantageously follows from this: in the case of such configurations, there is less or no need to seal and protect the transducer itself from precipitation.

[0037] In an optional development, it may likewise be advantageous for the transducer to be arranged on the side of the substrate facing the precipitation.

[0038] According to a development of the invention, it is provided that the transducer is arranged in the substrate.

[0039] In the configuration of the present invention, transducers may be arranged in multiple substrate layers.

[0040] The advantage arising from these configurations is that surface waves can be directly coupled by the transducer onto the substrate or protective panel, said surface waves propagating on the surface of the substrate or of the protective panel to be cleaned, thereby avoiding possible scattering and losses, e.g. due to dispersion inside the substrate.

[0041] A development enables the substrate to have a thickness recess in which the transducer is at least partly inserted, so that a low installation height is achieved in an advantageous manner.

[0042] According to the configuration, it is optionally possible that the at least two transducers are in each case grouped into at least one transducer group.

[0043] The invention can be developed by the transducers of at least one transducer group being actuated together and / or corresponding to one another, for example by being spaced apart, in a corresponding geometric arrangement, but being substantially centered and aligned relative to one another.

[0044] As a result of providing a transducer group made up of at least two transducers, these transducers can interact in such a way that, for example, constructive interference or standing waves can be produced between two spaced transducers of the transducer group.

[0045] One development optionally results in at least two transducer groups being operable. Optionally, it is possible for the at least two transducers to have the same embodiment. In a further configuration, it is possible for at least two, three or four transducer groups to be arranged in such a way that the transducers form a ring-shaped structure, i.e., are arranged along the ring-shaped structure in the circumferential direction.

[0046] This is advantageous because it allows for the creation of an extensive lattice-like structure of standing waves, which can be modified by modulation of the acoustic waves emitted by the transducer.

[0047] A further measure to influence the amplitude of the ultrasound waves within the protective panel in a targeted manner may consist of the protective panel having internal structures to deflect and / or attenuate the ultrasound waves introduced in. These structures may be omissions, interfaces, or fillers made from materials with stronger or weaker attenuation properties.

[0048] Although in principle it is technically possible to bond at least one transducer onto a protective panel on a surface that is to be protected from humidity and moisture, it is preferred that the at least one transducer is connected from the side of the optical unit of the monitoring device in such a way that the surface of the protective panel is found on that side, where the transducer is better protected from solar radiation and humidity and where the electrical connection is more easily implemented.

[0049] According to a further configuration, at least one transducer may be enabled to be operated in the first mode by a frequency-modulated signal. Optionally, the frequency-modulated signal may have a time-varying modulation (sweep). As a result of the frequency modulation, inaccuracies in the arrangement and configuration of individual components (e.g., transducers, substrates or protective panels, possible connection layers, cabling, etc.) acoustically involved in the cleaning process may be compensated for.

[0050] Optionally, the invention can be developed by operating the transducer in a second mode with an amplitude modulated signal. For development purposes, the amplitude modulated signal may have a time-varying modulation (sweep). As a result of the amplitude modulation, the front of the maximum wave energy is spatially displaced, which advantageously results in an increased cleaning power of the system.

[0051] In a further configuration, the transducers are optionally operated in a third mode by a phase-modulated signal. For development purposes, the phase-modulated signal may have a time-varying modulation (sweep). As a result of the phase modulation, the wave maximum of the standing wave formed between the two transducer groups is advantageously moved back and forth in the direction formed between the transducer groups.

[0052] According to a further development, it may be possible for the mode to be changeable in a sequential manner, in this way the system can advantageously be adapted to different types of contamination.

[0053] In one embodiment, the actuation circuit includes a linear amplifier. The invention can be further developed by having an input signal to the linear amplifier be a summed signal of individual signals of different frequencies. According to one embodiment, at least one of the frequency filters is arranged downstream of the linear amplifier. A further development allows at least one transducer to have an electrode arrangement that is excitable in a frequency-dependent manner.

[0054] The advantage arising from the above specified configuration is that only one amplifier is required for operating different transducers with different frequency ranges, resulting in a more compact and efficient overall system.

[0055] One configuration optionally produces an actuation circuit that includes a nonlinear amplifier. This is advantageous in that the nonlinear amplifier generates harmonics. These harmonics may be used in addition to the carrier signal to actuate additional transducers or additional electrodes of the same transducer without the need for additional hardware. As a result, the device design is simplified and easier to manufacture.

[0056] According to a further configuration, the apparatus is provided with a temperature management system. A development may provide that the temperature management system monitors the temperature of the apparatus, in particular of the transducer and / or of the substrate. One configuration may optionally provide that the temperature management system adjusts the power intake of the transducer depending on the temperature. One configuration may optionally provide that the temperature management system has a temperature-dependent circuit breaker. Optionally, for development purposes, it is provided that the circuit breaker is resettable.

[0057] The thermal management system according to the above configuration has the advantage that overheating of individual components of the device can be recognized and avoided. In this way, damage or functional deterioration of the components, for example as a result of an increased energy supply, can be avoided. For example, a certain temperature range can be provided for the transducer material, possibly a connecting layer present, and / or a substrate or protective panel, within which the function or certain properties of the components can be ensured.

[0058] According to a further development, it can be provided that the circuit breaker is not resettable, which advantageously achieves that the circuit for supplying the transducer is not inadvertently closed again, which would possibly cause the transducer to overheat.

[0059] An optional configuration allows the circuit breaker to have a control signal output. A development may result in a generator or amplifier for the transducer signal being operable by the control signal of the circuit breaker. In a further configuration, it may be possible for the control signal to be induced in a thermal management system. The resulting advantage is that the device can be switched by the control signal depending on the switching state of the circuit breaker. This ensures that a temperature increase above the switching threshold of the circuit breaker is prevented in an additional way. This has the advantage that the safety of the device is further increased.

[0060] For implementation purposes, the circuit breaker may be allowed to have good thermal contact with the transducer and the substrate.

[0061] In a development of the invention, the temperature management system may be provided with a temperature sensor. The invention may be configured in that the temperature sensor has good thermal contact with the transducer and the substrate. In a development, it may be provided that sensor data of the temperature sensor can be used to control a signal to the at least one transducer. The invention may be developed in that the signal to the at least one transducer can be adjusted in terms of amplitude, frequency, or pulse width depending on the sensor data. An NTC thermistor, a PTC thermistor, a thermistor, a diode, a thermocouple, or any other suitable means for determining temperature may be used as the temperature sensor.

[0062] The advantage resulting from the above-described configuration of the invention with a temperature sensor is that it is possible both to detect when a maximum temperature is exceeded and to determine the temperature curve, for example as a function of the power supplied to the transducer, so that the system can be advantageously adjusted without the switching threshold being exceeded after the limit temperature is reached and without the system being completely deactivated.

[0063] As an aside, it should be noted that the transducer is acoustically coupled to the protection panel in a manner known per se, in this case by adhesive bonding using, for example, an epoxy resin which, after curing, is very hard, and which facilitates good transmission and introduction of ultrasound waves into the protection panel.

[0064] In a development of the invention, it is optionally possible for at least one transducer to be captively connected to the substrate or protective panel by means of a connecting layer, which is arranged between the substrate or protective panel and the transducer, and which comprises a connecting material and a filling material.

[0065] In a development of the invention, the connection layer is a layer that tightly connects the transducer to the substrate or protective panel. Optionally, this can be achieved by an adhesive layer. Optionally, the connection material ensures adhesion of the transducer on the substrate or protective panel, said connection material having material-specific mechanical and acoustic connection material properties. Optionally, the filler material can also contribute to adhesion, but can also define the distance between the substrate or protective panel and the transducer. The filler material also has material-specific mechanical and acoustic filler material properties. In a development of the invention, it is possible for the connection layer to connect the transducer, the substrate or protective panel, and / or the filler material to one another, in particular to connect them to one another in a tightly contacting manner, and in a more detailed configuration of the invention, it is possible for the connection layer to be substantially gas-free.

[0066] The advantage of providing a connecting layer made of a connecting material and a filling material is that the connecting layer can be influenced both in terms of its mechanical properties, i.e., for example, density, hardness, or viscosity, and in terms of its acoustic properties, such as the sound propagation velocity, for example, by selecting the material composition of the connecting layer. In this way, it is possible to set the acoustic impedance difference or acoustic impedance contrast between the impedances of the respective regions of the material of the transducer and the material of the substrate or protective panel. As a result, it is advantageously possible to influence whether and to what extent there is reflection of sound energy at the interfaces between the transducer and the connecting layer and between the connecting layer and the substrate or protective panel. Furthermore, a further advantage is provided by the fact that the transducer can be precisely aligned to the substrate, especially by selecting a filling material that can provide mechanical stability to the connecting layer. Precise alignment of the transducer in relation to the substrate or protective panel is advantageous in that the sound waves generated by the transducer are coupled into the substrate or protective panel in an optimal manner, and that the sound waves propagate in a defined manner in those substrates or protective panels.

[0067] A particularly preferred embodiment of the invention allows for a filler material to establish a defined distance between the transducer and the substrate or protection panel, the distance defined by the filler material being advantageous in particular in view of bonding the transducer to the substrate or protection panel and for the alignment of the transducer relative to the surface of the substrate or protection panel.

[0068] In a more detailed configuration of the present invention, at least one molded body may form an acoustic bridge from the filler material by means of coupling the transducer and the substrate or the protective panel. According to a further development of the present invention, at least one molded body may be solid, preferably solid throughout. The present invention may be further developed in that the at least one solid body has dimensions corresponding to the distance. As a result, from a mechanical point of view, the distance between the transducer and the substrate or the protective panel is fixedly and uniquely determined by the filler material in an advantageous manner. The at least one molded body may form a matrix containing the filler material within the connecting material. A further advantage resulting from acoustically coupling the transducer to the substrate or the protective panel by means of acoustic bridging of the filler material, i.e., by means of direct material contact between the connecting material and the transducer and the substrate or the protective panel, is that, inter alia, the acoustic properties of the connecting layer can be influenced thereby. In this way, it is possible to additionally advantageously influence the impedance contrast between the transducer and the connection layer and between the connection layer and the substrate or protective panel.

[0069] A development of the present invention allows the at least one shaped body to be spherical or rod-shaped. According to a development of the present invention, the diameter of the at least one shaped body can correspond to a fraction of the operating frequency of the transducer. For construction purposes, the diameter of the at least one shaped body can be between 1 and 1000 μm, preferably between 1 and 100 μm, and particularly preferably between 30 and 50 μm. A development of the present invention optionally allows the at least one rod-shaped body to be arranged in a lying or standing manner. The advantageous result of the spherical or rod-shaped arrangement of the at least one shaped body is that the one or more shaped bodies can be well dispersed in the connecting material and are always present at defined positions in the connecting material, which has a significant effect on the transmission of sound waves from the transducer to the substrate or the protective panel.

[0070] As already indicated, a particularly preferred embodiment of the invention allows the protection panel to be integrated into the protection panel of the vehicle or arranged on the protection panel from the outside. This solution is ideal for a forward-facing camera in a car, for example, because the already known camera position in the area of ​​the conventional rearview mirror can be maintained, from which an ideal field of view for the camera emerges.

[0071] For example, integration into a protective panel can be realized in such a way that the protective panel, which is further implemented as an additional protective panel, forms the outer panel (outer glass layer) of the laminated glass panel. However, even in that case, the sensor is preferably not located at the edge of the entire protective panel, but instead around the edge area of ​​the camera's field of view, which occupies only a small part of the overall area. The laminated glass panel can be any panel in a vehicle, such as a rear window, or another protective shield, such as used as a vision window in a machine tool. Furthermore, the protective panel can be provided solely for the purpose of protecting the camera lens or the optical unit of a scanner.

[0072] In a particularly advantageous embodiment of the invention, at least one transducer is arranged between the layers of the laminated glass panel, which arrangement does not require additional space and in particular makes it possible to maintain the original dimensions of the protection panel, which are already known in principle. The transducer is adhesively bonded to the outer panel of the laminated glass panel before the two layers are connected by the layer of lamination between them.

[0073] In a first embodiment with a transducer integrated into the laminated glass panel, it is possible that at least one transducer is implemented in a layer of the laminate of the laminated glass panel, where a particularly simple product is produced in principle by using components of a conventional laminated glass panel.

[0074] For reasons of signal attenuation, it may be advantageous if the lamination layer and / or the inner panel of the laminated glass panel is omitted in the region of the field of view or scanning field of the monitoring device and / or of at least one transducer. Omission of the lamination layer means that the transducer and the region of the field of view or scanning field are not weakened by the lamination material, and therefore a higher level of efficiency can be achieved. Here, the transducer is in the cavity between the two glass panes, which would otherwise be in bare form if the inner panel is also omitted in this region.

[0075] If the additional protective panel is not an integral component part of the protective panel, it is preferred that the additional protective panel is attached to the protective panel using an adhesive on the outside, i.e., on the side where precipitation is expected, regardless of the condition of the protective panel.

[0076] The external attachment is preferably achieved in such a way that a cavity in which at least one transducer is arranged is provided between the additional protective panel and the main protective panel, the cavity avoiding damping effects that may worsen the cleaning action.

[0077] Depending on the necessity, it may be advantageous if the additional protective panel is arranged in a recess or cutout of the main protective panel, so that its outer side ends flush with the outer side of the additional protective panel of the camera or any other optical device. Such an arrangement may be particularly advantageous, for example, if, according to a preferred development of the invention, a wiper is provided whose wiping area only covers the field of view or scanning area of ​​the monitoring device, the vehicle's protective panel which includes the field of view or scanning area of ​​the monitoring device, or the vehicle's protective panel without the field of view or scanning area of ​​the monitoring device.

[0078] However, a preferably provided wiper, which may have one or more wiper arms with wiper blades, may only cover a wiping area that is limited to the field of view or scanning field of the monitoring device or excludes the field of view or scanning field of the monitoring device.

[0079] The respective concepts may depend on the field of use, the type of ultrasound introduced, and optionally further considerations. In certain situations, the field of view additionally cleaned by the wiper provides an improved cleaning action, especially in cases of soiling with little or no water if a wiper water device is used. However, additional cleaning of the field of view or scanning field of the monitoring device by the wiper may also be intentionally omitted, for example, because the field of view or scanning field is also covered by the wiper gliding past for at least a short period of time, during which time signal evaluation cannot be performed.

[0080] A further particularly advantageous measure allows the protection panel to be made of a transparent ceramic material. Generally, ceramic materials are harder than glass, offering particularly favorable properties for the introduction and propagation of ultrasound waves with minimal attenuation. Furthermore, the ceramic material offers a longer service life under mechanical stress, for example in the case of stone chips in vehicles, because the surface quality is less affected by high-speed impacting debris. This embodiment is particularly suitable for solutions in which an additional protection panel is attached to an existing windscreen or any other protection panel, partially within the camera's field of view. An embodiment with a separate ceramic overlay is particularly preferred and can be adapted to all types of protection panels, provided that the ceramic overlay is provided at least within the field of view or scanning field of the monitoring device, regardless of whether it is part of the protection panel or is adhesively bonded to it from the outside. The outstanding durability of ceramic materials is further advantageous in that the surface is less susceptible to wear in the case of the additional use of a mechanical wiper system. The ceramic material may be applied directly onto the surface of the lens, the lens of the optical monitoring device thus forming itself a protective panel.

[0081] The subject matter of the invention further relates to a control system for autonomous driving of a motor vehicle, whereby one or more monitoring systems are provided according to one or more of claims 1 to 18 or according to different claims.

[0082] Further features, details and advantages of the invention emerge from the wording of the claims and from the following description of exemplary embodiments based on the drawings, the details of which are as follows: [Brief explanation of the drawings]

[0083] [Figure 1] FIG. 1 shows a cross section of laminated glass with an additional protective panel applied thereon. [Figure 2]FIG. 2 shows an oblique view onto the laminated glass according to FIG. 1 with the illustrated layers of the laminated glass. [Figure 3] FIG. 2 shows a plan view of an additional protective panel according to FIG. 1. [Figure 4] FIG. 2 shows a perspective view onto the laminated glass according to FIG. 1 without an additional protective panel. [Figure 5] FIG. 1 shows a cross section of a flat laminated glass with an additional protective panel arranged thereon. [Figure 6] FIG. 6 shows an oblique view onto the laminated glass according to FIG. 5. [Figure 7] 10 shows a cross section of a further embodiment with a cavity in the laminated glass provided in the region of the transducer. FIG. [Figure 8] FIG. 8 is a diagram showing an oblique view onto the laminated glass according to FIG. 7. [Figure 9] FIG. 10 shows a cross section of a further laminated glazing with a transducer integrated between the panes. [Figure 10] FIG. 10 is a diagram showing an oblique view onto the laminated glass according to FIG. [Figure 11] 1A-1C show schematic illustrations of four embodiments of a transducer of a monitoring system; [Figure 12] 10A-10C show schematic illustrations of two further embodiments of a transducer of a monitoring system; [Figure 13] 1A-1C show schematic illustrations of three configurations for transducer shaping of a surveillance system. [Figure 14] 1A-1C each show, in a schematic illustration, two configurations of transducer placement in relation to the edge region of a protection panel of a surveillance system. [Figure 15] 1A-1C show schematic cross-sectional illustrations of five possible transducer positioning variations in relation to the protection panel of the surveillance system; [Figure 16] FIG. 1 shows a schematic illustration of a group of transducers for generating standing waves within a protection panel of a surveillance system. [Figure 17]10A-10C show three further schematic illustrations of at least two transducer groups for generating standing waves within a protection panel of a monitoring system. [Figure 18] 1A-1C show schematic illustrations of different modes in which a transducer of a monitoring system can operate. [Figure 19] 10A-10C show schematic wiring diagrams for two alternatives for the transducer actuation circuit of the monitoring device. [Figure 20] 10A-10C show schematic wiring diagrams for four alternatives for a thermal management system for monitoring the operating temperature of a transducer of a monitoring device. [Figure 21] FIG. 2 shows a schematic cross-sectional illustration of a protective panel of a monitoring device with a transducer disposed thereon. [Figure 22] 10A-10C illustrate an embodiment of the connection of each transducer to a protective panel of the monitoring device. DETAILED DESCRIPTION OF THE INVENTION

[0084] The embodiments of the surveillance system described below each have a camera or other optical device with an assigned lens and a protective panel, not illustrated in the drawings, which may be configured in various embodiments. Identical or similar elements are represented by the same reference numerals in the following figures. The protective panel is either additionally attached to a protective panel, which here is embodied as a laminated glass pane for use in automobiles, for example (see FIGS. 1-6), or is integrated into the protective panel embodied as such a laminated glass pane. Particularly advantageous are embodiments in which the protective panel is specifically configured to protect the camera, for example, embodied as a transparent bell or as a transparent end of the camera housing. The cross sections of all these protective panels, which are shaped completely differently and possibly strongly curved, may be substantially identical in terms of construction. In all illustrated exemplary embodiments, the camera's field of view is limited to the area between the transducers 10, which introduce ultrasound waves into the protective panel in a targeted manner to remove precipitation, which should further be understood to mean, in addition to rain, ice, frost, and condensed water, among others, from the camera's field of view. The preferred frequency range of the introduced ultrasound is in the range between 0.5 and 5 MHz, although it is not necessary for all transducers provided respectively within the camera system to emit at the same frequency.

[0085] 1 shows a first embodiment of a camera system 1 having an additional protective panel 12 attached with the aid of glass adhesive 16 to the weather-exposed outer side of an additional protective panel 14 made of laminated glass. Here, the additional protective panel 12 is made of a ceramic material and is at a predetermined distance from the outer glass layer 18 of the laminated glass, so that a cavity 19 remains between the outer glass layer and the additional protective panel 12. Four transducers 10 are arranged in a ring-shaped manner within the cavity around the field of view of the camera, the camera being arranged on the opposite side, on the inner side of the laminated glass of the additional protective panel 12. Due to the hardness of the ceramic material, it has exceptional resistance to surface abrasion, so that the view for the camera is maintained for a longer period and the field of view is less susceptible to stone chips and the like.

[0086] The uniqueness of the protective panel 14 illustrated in the section in Figures 1 to 4 consists in that the additional protective panel 12 is arranged in a recess 20 arranged in the edge region of the protective panel. As a result, the additional protective panel can end with its outer surface flush with the outer surface of the protective panel. In this way, it is possible to select a different material for the additional protective panel 12 than for the protective panel 14 itself (in this case, a harder material) and to clean both surfaces with a common wiper that complements the cleaning effect of the ultrasonic transducer 10 in the area of ​​the protective panel 12. In the case where a wiper is provided, the wiping area of ​​the wiper also targets the protective panel 12. Ideally, the recess is adapted to the shape of the protective panel.

[0087] For illustrative purposes, Figures 2-4 show perspective views of a simple variant in which protective panels are flush with and adjacent to a higher area. Here, the arrangement of four transducers 10 around the periphery of the camera's field of view can be easily seen. The transducers 10 can emit ultrasound waves with different frequencies and waveforms. There may also be an offset number of transducers arranged to the sides of the field of view.

[0088] In FIG. 2 it is also possible to see the construction of the protective panel 14, conventionally as laminated glass, having the previously mentioned outer glass layer 18, inner glass layer 22 and laminate layer 24 between the glass layers.

[0089] While Figure 3 shows a plan view, the additional protective panel has been omitted in the illustration of Figure 4 to better show transducer 10. Again, the transducer is not affixed to the outer surface of protective panel 14, but instead is affixed to and acoustically coupled to the inner surface of protective panel 12.

[0090] 5 and 6 show a further camera system 100, in which a protective panel 114, made of laminated glass and conventional in principle, is provided in the field of view of a camera (not shown here) with an additional protective panel 112, which is again attached to the outer face of an outer glass layer 118 by means of glass adhesive 116. Again, a cavity 119 is provided between the additional protective panel 112 and the surface of the protective panel 114, and a transducer 10, acoustically coupled to the inner face of the protective panel 112, is arranged in said cavity. Since the additional protective panel in this solution protrudes above the outer face of the protective panel, it is not possible to clean the outer face of the additional protective panel 112 with the protective panel wiper, so the additional protective panel 112 is arranged outside the wiping area, and precipitation is only removed by ultrasonic means.

[0091] 7 and 8 show an embodiment of a camera system 200 in which an additional protective panel 214 made from laminated glass has a layer 224 of lamination omitted in the area of ​​the camera's field of view, while the outer glass layer 218 directly assumes the function of a hitherto separate additional protective panel for the camera system 200. Again, four piezo transducers 10 limit the camera's field of view to the sides, and optionally a support structure 226 may be used in the omitted area of ​​the inner glass layer, which may maintain the electrical connection for the transducers and also serve as a housing for the camera.

[0092] The construction of the protection panel 214 can be easily seen in FIG. 8. The area where the four transducers 10 were arranged around the camera's field of view has been removed from the laminate layer 224 between the inner and outer glass layers; however, the four transducers are now acoustically coupled directly to the outer glass layer 218 of the protection panel. The transducer 10 arrangement, ultrasonic frequency, and ultrasonic waveform are set such that the ultrasonic amplitude is particularly large, particularly in the camera's field of view, to result in ideal removal of moisture in that field of view. Optionally, structures that facilitate targeted propagation of ultrasound may be provided in the outer glass layer 218.

[0093] The protective panel 214, implemented as a laminated glass panel, may extend significantly beyond the field of view of the camera to the side, so that the protective panel area shown with the transducers only forms a partial area of ​​the entire protective panel. In this embodiment, the wiping area of ​​the wiper can also cover the field of view of the camera without any problem, if this is desired.

[0094] Finally, Figures 9 and 10 present yet another embodiment of the camera system 300, in which the transducers 10 are embedded in the laminate layer 324 of a protective panel 314 made of laminated glass. Here, the height of the transducers 10 is matched to the thickness of the laminate layer 324. Incidentally, the camera's field of view is again in the area between the transducers 10, which are acoustically coupled to the outer glass layer 318 of the protective panel. Of course, the camera's field of view can easily be additionally cleaned, possibly with an existing wiper. If the glass layer and, in addition, the laminate layer as a visual window, extend even further, the camera's field of view would again occupy only a small portion of the larger panel. Again, structures in the outer glass layer 318 can help focus the ultrasound waves into the camera's field of view, if this is deemed necessary.

[0095] Figures 11a) to 11d) show a schematic representation of the transducer 10 in four different embodiments 10a, 10b, 10c and 10d.

[0096] The transducer 10a from FIG. 11a) has regularly spaced electrodes 1111.

[0097] The transducer 10b from Fig. 11b) comprises at least one first electrode 1111 and at least one second electrode 1121. The first electrode 1111 and the second electrode 1121 are arranged alternately in the embodiment 10b of the transducer 10 according to Fig. 11b). The second electrode 1121 has a discontinuous embodiment, while the first electrode 1111 has a continuous embodiment.

[0098] FIG. 11c) illustrates a further embodiment 10c of the transducer 10, according to which the first electrodes 1111 are grouped into a first electrode group 1110 and the second electrodes 1121 are grouped into a second electrode group 1120. In this exemplary embodiment, the electrode groups 1110, 1120 do not overlap. The dimensions and spacing of the first electrodes 1111 in the first electrode group 1110 are substantially identical. The same applies to the distances and dimensions of the electrodes 1121 in the second electrode group 1120.

[0099] Figure 11d) shows a further embodiment 10d of the transducer 10, which embodiment substantially corresponds to embodiment 10c, with the exception that a first electrode group 1110 with a first electrode 1111 is arranged in a first transducer portion, which is spatially separated from a second transducer portion in which a second electrode group 1120 with a second electrode 1121 is arranged.

[0100] Figure 12a) shows a further embodiment 10e of the transducer 10, in which the transducer 10e is divided into two regions 1030 and 1040, with a first group of electrodes 1110 arranged in the first region 1130 and a second group of electrodes 1120 arranged in the second region.

[0101] Figure 12b) shows an alternative embodiment 10d of the transducer 10, where the transducer 10f is similarly subdivided into regions 1030 and 1040. This embodiment is distinguished by the fact that the regions 1130 and 1140 are not continuous in each case, but are arranged alternately along the transducer 10f. Otherwise, the arrangement of the transducer 10f corresponds to the arrangement of the transducer 10e from Figure 12a). The transducer is essentially arranged here without breaks, i.e. in a continuous manner.

[0102] In the embodiment according to FIG. 12b), the transducer 10f has a horseshoe-shaped or U-shaped embodiment, the second region 1140 being arranged in the corner region of the transducer 10f, and the first region 1130 being arranged between the end and the corner region of the transducer 10f.

[0103] 13 shows three further embodiments 10g, 10h, and 10i of the transducer 10, all of which have a U-shaped or horseshoe-shaped form. The transducer 10 according to embodiment 10g does not have dedicated corner areas, while the transducer 10 embodiment 10h has sharp corner areas and the transducer 10 embodiment 10i has rounded corner areas of the horseshoe-shaped transducer 10.

[0104] FIG. 14 schematically illustrates two exemplary embodiments for the arrangement of transducers 10 on a substrate or protective panel 14. The transducers 10, 10j are formed parallel to edges 1410, 1420. Here, the edges 1420 are curved, so that the transducers 10j also have a curved shape. It goes without saying that this exemplary embodiment is not limited to this shape, and other edge or transducer shapes may also be provided. Similarly, the edge distance 1430 between the transducers 10, 10j and the respective edges 1410 and 1420 can be adjusted depending on the frequency of the sound waves generated by the respective transducers 10, 10j, so that the sound waves reflected at the edges 1410, 1420 constructively interfere with the sound waves emitted by the transducers 10, 10j.

[0105] FIG. 15 shows various embodiments of the arrangement of the transducer 10 on the substrate or protective panel 14. According to the embodiment according to FIG. 15a), the transducer is arranged in the gap 1510 between the substrate or protective panel 14 and a further panel 1530. According to FIG. 15b), the transducer 10 is arranged on a given side of the substrate or protective panel 14, for example, possibly the side opposite to possible precipitation on the substrate or protective panel 14. FIG. 15c) shows a further embodiment of the transducer arrangement, in which the transducer is introduced into a laminate panel. The panel has a layer 22 of lamination between the substrate or protective panel 14 and the further panel 1530. The transducer 10 is arranged or laminated in this layer of lamination. FIG. 15d) similarly relates to a laminate panel made of a substrate or protective panel 14 with the transducer 10, a layer 22 of lamination, and a further panel 1530. Here, the transducer is arranged in a thickness recess 1520. In this exemplary embodiment, the thickness recess 1520 is formed as a cutout in the layer 22 of the stack and in the further panel 1530. Finally, FIG. 15e) relates to an embodiment according to which the further panel has a three-dimensional form and forms a container space for the substrate or protective panel 14 with the transducer 10 arranged thereon. The transducer 10 is arranged on the side of the substrate or protective panel 14 facing the further panel 1530. The substrate or protective panel 14 is connected to the further panel 1530 by the layer 22 of the stack, into which the transducer 10 is inserted or laminated.

[0106] 16 shows an exemplary embodiment of an arrangement of two transducers at 1611, 1612. The two transducers 1611, 1612 form a first transducer group 1641. The transducers 1611, 1612 are substantially aligned and centered on each other along a central axis, and each has a long side and a short side. The transducers 1611, 1612 therefore have a substantially rectangular embodiment. The transducers 1611, 1612 oppose each other with their long sides in each case. The distance between the transducers 1611, 1612 is dimensioned so that the distance substantially corresponds to a multiple of the wavelength of the surface or of the spatial wave generated by the transducers 1611, 1612. The transducers 1611, 1612 emit ultrasonic waves 1621, 1622 and are operated with substantially the same frequency, amplitude and phase. As a result of the transducers 1611, 1612 being arranged opposite each other, a standing wave 1631 with a large amplitude forms between the transducers 1611, 1612.

[0107] 17a)-c) show three further embodiments of arrangements of transducer groups 1741, 1742, 1743, 1744, each including at least two of transducers 1711, 1712, 1713, 1714, 1715, 1716, 1717, 1718.

[0108] The embodiment according to Fig. 17a) shows a crossed arrangement of two transducer groups 1741, 1742, the first transducer group having two transducers 1711, 1712 corresponding to the exemplary embodiment according to Fig. 16, and the second transducer group 1742 having two transducers 1713, 1714 in the same way. In the wave propagation direction, the first transducer group 1741 is aligned substantially orthogonally to the second transducer group 1742. The standing wave 1731 formed between the transducers 1711, 1712 of the first transducer group 1741 thus spreads substantially orthogonally to the standing wave 1732 formed between the transducers 1713, 1714 of the second transducer group 1742. Interference between the standing waves 1731, 1732 causes a grid-like pattern of wave troughs and crests to form between the transducers 1711, 1712, 1713, and 1714, with the grid squares being rectangular.

[0109] The embodiment according to Fig. 17a) shows an arrangement of three transducer groups 1741, 1742, 1743, the first transducer group having two transducers 1711, 1712 corresponding to the exemplary embodiment according to Fig. 16, the second transducer group 1742 likewise having two transducers 1713, 1714 and the third transducer group 1743 likewise having two transducers 1715, 1716. The transducer groups 1741, 1742, 1743 with pairwise opposite transducers 1711, 1712, 1713, 1717, 1715, 1716 are arranged in such a way that a substantially hexagonal outer periphery of the arrangement results. An angle of approximately 60° is formed in each case between the wave propagation directions of the standing waves 1731, 1732, 1733 of two transducer groups 1741, 1742, 1743 that are adjacent to each other in the circumferential direction of the arrangement. Due to the interference between the standing waves 1731, 1732, 1733, a grid-like pattern of wave troughs and crests is formed between the transducers 1711, 1712, 1713, 1714, 1715, and 1716, the grid squares being triangular.

[0110] The embodiment according to Fig. 17c) shows a further arrangement of four transducer groups 1711, 1712, 1713, 1714, the first transducer group having two transducers 1711, 1712 corresponding to the exemplary embodiment according to Fig. 16. The second transducer group 1742 similarly has two transducers 1713, 1714 and is arranged substantially orthogonal relative to the first transducer group 1741, with the respective wave propagation directions between the transducers 1711, 1712, 1713, 1714 of the transducer groups 1741, 1742. The third transducer group 1743 and the fourth transducer group 1744 similarly have two transducers 1715, 1716 and 1717, 1718, respectively. An approximately 45° angle is subtended between the wave propagation direction of standing wave 1731 of first transducer group 1741 and the wave propagation direction of standing wave 1733 of third transducer group 1743. An approximately 45° angle is similarly subtended between the wave propagation direction of standing wave 1732 of second transducer group 1742 and the wave propagation direction of standing wave 1734 of fourth transducer group 1744. This results in a substantially octagonal outer perimeter of the arrangement. Interference between standing waves 1731, 1732, 1733, 1744 causes a lattice-like pattern of wave troughs and crests to form between transducers 1711, 1712, 1713, 1714, 1715, 1716, 1717, and 1718.

[0111] Figures 18a) and b) show an exemplary embodiment for the mode of operation of the transducer 10. The transducer 10 is supplied with a driver signal by a generator (not illustrated here) and generates ultrasonic waves 1810. In Figure 18a), these ultrasonic waves 1810 emitted by the transducer 10 arranged on a substrate or protection panel 14 have amplitude modulation.

[0112] Fig. 18b) illustrates a mode of operation for an exemplary embodiment of the transducer arrangement according to Fig. 17a). The transducers 1711, 1712 of the first transducer group 1741 are actuated by phase-modulated driver signals, while the transducers 1713, 1714 of the second transducer group 1742 are likewise actuated by phase-modulated driver signals. In this way, the maxima of the interfering standing waves 1731, 1732 are displaced.

[0113] 19a) and 19b) show an embodiment of one actuation circuit 1910, 1911 respectively for the transducer 10. FIG.

[0114] According to the embodiment according to Fig. 19a), the actuation circuit is supplied with at least one signal 1920, the at least one signal 1920 having a specific frequency. The at least one signal 1920 is added by means of an adding unit 1925 to form a summed signal 1928. This summed signal 1928 is amplified by means of an amplifier 1930, which in this embodiment is implemented as a linear amplifier. A respective filter 1940 is arranged in the further signal path upstream of at least one transducer 10. Each filter 1940 has an input for the amplified summed signal 1928 leaving the amplifier 1930 and at least one limiting frequency, so that only a certain frequency range of the amplified summed signal 1928 is sent to the respective transducer 10.

[0115] Φ lγAccording to the embodiment according to .19β), a signal 1920, which is amplified by an amplifier 1930, which in this embodiment is implemented as a non-linear amplifier, is provided to an actuation circuit 1911. Harmonics are generated by the amplifier 1930, said harmonics are separated from the amplified signal 1920 by filters 1940, each of which has at least one limiting frequency, and said harmonics are supplied to at least one transducer 10 in a manner in which they are correspondingly separated.

[0116] 20a)-20d) show different embodiments of a thermal management system 2000 for an actuation circuit according to any one of the exemplary embodiments from FIG. 19. According to the embodiment according to FIG. 20a), the thermal management system 2000 comprises a circuit breaker 2010 arranged between the amplifier and the transducer. The circuit breaker 2010 can be reset manually and / or automatically. According to FIG. 20b), the thermal management system 2000 comprises a circuit breaker 2010 with a control signal output 2040 from which a control signal 2045 is derived to the amplifier 1930. The amplifier can be switched by this control signal 2045, so that the signal to the transducer 1930 is switched depending on the control signal 2045. 20c) relates to an embodiment of a thermal management system 2000 according to which the circuit breaker is connected to a control unit 2020 by means of a signal output 2040, the control unit 2020 controlling the switching state of the amplifier 1930 depending on the signal provided by the signal output 2040 of the circuit breaker 2010. FIG. 20d) relates to a further embodiment of the thermal management system 2000. In this embodiment, the thermal management system comprises a temperature sensor 2011. By way of example, the temperature sensor 2011 may be implemented as an NTC or PTC thermistor. The temperature sensor is operated by a temperature sensor circuit 2030. The temperature sensor circuit 2030 has a signal output 2040 to which the control unit 2020 is connected. The control unit 2020 controls the switching state of the amplifier 1930 depending on the signal provided by the signal output 2040 of the circuit breaker 2010.

[0117] 20e) shows a possible embodiment of the arrangement of the thermal management system 2000, of the circuit breaker 2010 or of the temperature sensor 2011, where the temperature sensor 2011 or the circuit breaker is placed in the marginal area of ​​the connection layer 16 arranged between the substrate or protection panel 14 and the transducer 10.

[0118] 21a) to 21g) show different embodiments of a protective panel 14 and a transducer 10 arranged thereon.

[0119] 21a) to 21d) relate to the installation of a protective panel 14 or of a substrate in a panel frame 2110. Here, according to the variant according to FIG. 21a), the substrate or protective panel 14 has a Z-shaped embodiment in an abutment area 2130 at its outer periphery for engaging with a flange area 2115 of the panel frame 2110. A seal 2120 is arranged between the panel frame 2110, in particular the flange area 2115, and the substrate or protective panel 14, and in particular on the peripheral side of the abutment area 2130 of said substrate or protective panel 14. At least one transducer 10 is arranged on the inner side IS of the substrate or protective panel 14.

[0120] According to the variant according to Fig. 21b), the substrate or protective panel 14 has an S-shaped embodiment in an abutment area 2130 at its outer periphery for engaging with the flange area 2115 of the panel frame 2110. A seal 2120 is arranged between the panel frame 2110, in particular the flange area 2115, and the substrate or protective panel 14, and in particular on the peripheral side of the abutment area 2130 of said substrate or protective panel 14. At least one transducer 10 is arranged on the inner side IS of the substrate or of the protective panel 14.

[0121] In the embodiment according to Fig. 21c), the substrate or protective panel 14 has a substantially planar embodiment and adjoins on the inner side IS of the flange area 2115 of the panel frame 2110. A seal 2120 is arranged in the overlap area of ​​the flange area 2115 with the substrate or protective panel 14. At least one transducer 10 is arranged on the inner side IS of the substrate or of the protective panel 14.

[0122] According to the embodiment according to Fig. 21d), the substrate or protective panel 14 rests on its inner side against a flange area 2115 of the panel frame 2110. A seal, in particular an O-ring seal, is arranged between the flange area of ​​the panel frame and the substrate or protective panel 14. At least one transducer 10 is arranged on the inner side IS of the substrate or of the protective panel 14.

[0123] Figures 21e)-f) show preferred arrangements of different types of protective panel 14 or substrate and transducer 10 to not impair or only minimally impair the field of view through the substrate or protective panel 14.

[0124] According to the embodiment according to Fig. 21e), the substrate or protective panel 14 has a substantially oval shape in cross section with a flattened edge side, and at least one transducer 10 is arranged on the inner side IS of the substrate or protective panel 14 at the flattened edge side.

[0125] In the embodiment of the substrate or protective panel 14 according to Fig. 21f), the substrate or protective panel 14 has a drop-shaped cross section. At least one transducer 10 is arranged at the pointed end of the substrate or protective panel 14, which is embodied with a drop-shaped form, at an adjacent flange 2140 extending substantially parallel to the longitudinal axis of the substrate or protective panel 14.

[0126] According to the embodiment according to FIG. 21g), the substrate or protective panel 14 has a semicircular embodiment in cross section and has an adjacent flange on the inner side IS of which at least one transducer 10 is arranged.

[0127] 22 shows a schematic cross-sectional view of a substrate or protection panel 14 with a transducer 10 arranged thereon in a further embodiment. The transducer 10 is arranged on a surface 2211 of the substrate or protection panel 14. Between the substrate 14 and the transducer 10 there is a connecting layer or glass adhesive 16 having a connecting material 2231 and a filler material 2232.

[0128] In this embodiment, the connecting material 2231 contains a filler material 2232 in the form of a molding 2234, which is embodied as a sphere or cylinder. The molding 2234 forms a matrix for the connecting material 2231, so that the connecting layer or glass adhesive 16 is thus constructed from two components. The thickness of the connecting layer or glass adhesive 16 is determined by a predetermined distance 2233 defined by the molding 2234. The molding 2234 adjoins both directly to the transducer 10 and directly to the substrate or protective panel 14, forming an acoustic bridge.

[0129] All described camera systems are particularly suitable for inclusion in control systems of automobiles for autonomous driving, and particularly high signal quality can be obtained even under adverse external conditions due to targeted cleaning of the camera's field of view.

[0130] However, the present invention is not limited to one of the embodiments described above, but can instead be modified in many ways. For example, the camera system can be implemented independently of an already existing protective panel. In addition to the rear and side windows of the vehicle, camera systems with dedicated protective panels arranged in separate housings on the vehicle or integrated into other vehicle components, such as the rearview mirror, are also possible. A dome-shaped embodiment of the protective panel on the vehicle roof for good all-round visibility is particularly preferred.

[0131] Thus, in particular, the invention is not limited to cameras for autonomous driving of automobiles; instead, the invention may also be used in aircraft or ships for control or observation purposes.

[0132] In addition, the optical surveillance or camera system according to the invention may have a stationary embodiment, which may be particularly advantageous when precipitation may be present on the protective panel due to external conditions. By way of example, applications may include webcams, surveillance cameras in public spaces, wildlife monitoring cameras, or surveillance cameras in workspaces, such as machine tools. In addition to camera applications, embodiments according to the invention may also include other optical surveillance devices, such as laser scanners or angled mirrors, which are often used in military applications.

[0133] All features and advantages, including structural details, spatial arrangements, and method steps, that emerge from the claims, the description, and the drawings may be crucial to the present invention, both singly and in very different combinations. [Item of invention] [Item 1] 1. An optical monitoring system for monitoring a surrounding environment, comprising: an optical monitoring device, the field of view or scanning field of the optical monitoring device being captured by a lens; and a protective panel (12, 14, 114, 314, 112, 218, 318) that protects the lens from precipitation and covers at least the field of view or scanning field of the monitoring device, wherein the protective panel (12, 14, 114, 214, 314, 112, 218, 318) is acoustically coupled to at least one ultrasonic transducer (10, 10a-j, 1611, 1612, 1711-1718). [Item 2] 2. The optical monitoring system according to item 1, characterized in that the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) is arranged adjacent to the field of view or scanning field. [Item 3] 3. An optical monitoring system according to item 2, characterized in that at least two transducers (10, 10a-j, 1611, 1612, 1711-1718) are arranged around the field of view or scanning field. [Item 4] 4. An optical surveillance system as described in item 3, characterized in that three or more transducers (10, 10a-j, 1611, 1612, 1711-1718) are arranged around the edge of the field of view or scanning field in a distributed manner. [Item 5] 5. The optical surveillance system according to claim 3 or 4, characterized in that at least two transducers (10, 10a-j, 1611, 1612, 1711-1718) are arranged offset from one another, and the transducers emit the same or different ultrasonic frequencies and / or the same or different ultrasonic waveforms to the protective panel (12, 112, 218, 318). [Item 6] The optical monitoring system according to any one of items 1 to 5, characterized in that the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) is connected to the protective panel (12, 14, 114, 214, 314, 112, 218, 318) from the monitoring device side. [Item 7] 7. An optical monitoring system according to any one of items 1 to 6, characterized in that the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) comprises in each case at least one electrode group (1110, 1120) with at least one electrode (1111, 1121). [Item 8] 8. Optical monitoring system according to any one of claims 1 to 7, characterized in that the edge distance (1430) of the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) corresponds to a fraction or multiple of the wavelength of the sound wave produced by the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718). [Item 9] Item 9. An optical monitoring system according to any one of items 1 to 8, characterized in that at least two transducers (10, 10a-j, 1611, 1612, 1711-1718) are in each case grouped to form at least one transducer group (1641, 1741-1744), the transducers (10, 10a-j, 1611, 1612, 1711-1718) of the at least one transducer group (1641, 1741-1744) corresponding to one another by being actuated together and being centered and aligned with respect to one another. [Item 10] 10. An optical monitoring system according to any one of items 1 to 9, characterized in that the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) is operated by a frequency modulated signal in a first mode, by an amplitude modulated signal in a second mode, and by a phase modulated signal in a third mode, each mode having a time-variable modulation. [Item 11] 11. The optical monitoring system according to any one of claims 1 to 10, characterized in that the optical monitoring system comprises a temperature control system (2000) for monitoring the temperature of the optical monitoring system, in particular of the transducers (10, 10a-j, 1611, 1612, 1711-1718) and / or of the protective panels (12, 14, 114, 214, 314, 112, 218, 318). [Item 12] 12. The optical surveillance system according to any one of items 1 to 11, characterized in that the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) is tethered to the substrate or the protective panel (12, 14, 114, 214, 314, 112, 218, 318) by means of a connecting layer (16, 116), the connecting layer (16, 116) being arranged between the substrate or the protective panel (12, 14, 114, 214, 314, 112, 218, 318) and the transducer or the protective panel (12, 14, 114, 214, 314, 112, 218, 318), the connecting layer (16, 116) comprising a connecting material (2231) and a filling material (2232). [Item 13] Item 13. An optical monitoring system according to item 12, characterized in that at least one molded body (2234) made from the filling material (2232) is bonded to the transducer (12, 14, 114, 214, 314, 112, 218, 318) and the substrate or the protective panel (12, 14, 114, 214, 314, 112, 218, 318), thereby forming an acoustic bridge. [Item 14] 14. The optical monitoring system according to any one of items 1 to 13, characterized in that the at least one transducer (10, 10a-j, 1611, 1612, 1711-1718) is L-shaped or U-shaped. [Item 15] 15. The optical surveillance system according to any one of items 1 to 14, characterized in that the optical surveillance system is implemented as a camera, a laser scanner or any other surveillance optical unit. [Explanation of symbols]

[0134] 1, 100, 200, 300 camera systems 10, 10a-j, 1611, 1612, 1711, 1712, 1713, 1714, 1715, 1716, 1717, 1718 Ultrasonic transducers 12, 112 Additional protective panels 14, 114, 214, 314 Protection Panel 16, 116 Glass adhesive, connecting layer 18, 118, 218, 318 Outer glass layer 19, 119 hollow 20 recess 22, 122, 222, 322 Layers of stacking 24, 124, 224, 324 Inner glass layer 1110 First electrode group 1111 First electrode 1120 Second electrode group 1121 Second electrode 1130 First Area 1140 Second Realm 1410, 1420 Edge 1430 edge distance 1510 Gap 1520 Thickness recess 1530 Further Panels 1621, 1622, 1810 Ultrasound 1631, 1731, 1732, 1733, 1734 standing wave 1641, 1741, 1742, 1743, 1744 transducer group 1910, 1911 operating circuit 1920 signal 1925 Addition Unit 1928 added signals 1930 Amplifier 1940 Filter 2000 Temperature Control System 2010 Circuit Breaker 2011 Temperature Sensor 2020 Control Unit 2040 signal output 2045 control signal 2110 Panel Frame 2115 Edge area 2120 Sealing part 2130 Adjacent Areas 2140 Adjacent flange 2211 Surface 2231 Connecting materials 2232 Filling material 2233 Distance 2234 Molded body IS inner side

Claims

1. 1. An optical monitoring system for monitoring a surrounding environment, comprising: an optical monitoring device, the field of view or scanning field of the optical monitoring device being captured by a lens; and a protective panel (12, 14, 114, 314, 112, 218, 318) for protecting the lens from precipitation and covering at least the field of view or scanning field of the optical monitoring device, the protective panel (12, 14, 114, 214, 314, 112, 218, 318) is acoustically coupled to at least one ultrasonic transducer (10, 10a-j, 1611, 1612, 1711-1718); the optical monitoring system comprises a temperature management system (2000) configured to monitor the temperature of the transducers (10, 10a-j, 1611, 1612, 1711-1718) and / or of the protective panels (12, 14, 114, 214, 314, 112, 218, 318); The temperature control system (2000) is configured to adjust the power uptake of the transducers (10, 10a-j, 1611, 1612, 1711-1718) as a function of the monitored temperature. An optical surveillance system comprising:

2. 2. The optical monitoring system of claim 1, wherein the thermal management system (2000) comprises a temperature-dependent circuit breaker (2010).

3. 3. The optical surveillance system of claim 2, wherein the circuit breaker (2010) is not resettable.

4. 3. The optical surveillance system of claim 2, wherein the circuit breaker (2010) is resettable.

5. An optical surveillance system according to any one of claims 2 to 4, characterized in that the circuit breaker (2010) has a control signal output (2040).

6. 6. An optical monitoring system according to claim 5, characterized in that a generator or amplifier (1930) for the signals of the ultrasonic transducers (10, 10a-j, 1611, 1612, 1711-1718) is connected to the control signal output (2040) and is operable by a control signal (2045) of the circuit breaker (2010).

7. 7. An optical monitoring system according to claim 5 or 6, characterized in that the control signal (2045) is guidable to the thermal management system (2000).

8. The temperature control system (2000) comprises a control unit (2020), the control unit (2020) is connected to the control signal output (2040) and is configured to receive a control signal (2045) for the circuit breaker (2010); and, The control unit (2020) is configured to control the switching state of the amplifier (1930) depending on the control signal (2045) provided by the signal output (2040) of the circuit breaker (2010).

8. An optical surveillance system according to claim 7.

9. 8. The optical monitoring system of claim 2, wherein the circuit breaker (2010) is in thermal contact with the ultrasonic transducer (10, 10a-j, 1611, 1612, 1711-1718) and the protection panel (12, 14, 114, 214, 314, 112, 218, 318).

10. Optical monitoring system according to any one of claims 1 to 9, characterized in that the thermal management system (2000) comprises a temperature sensor (2011).

11. 11. The optical monitoring system of claim 10, wherein the temperature sensor (2011) is in thermal contact with the ultrasonic transducer (10, 10a-j, 1611, 1612, 1711-1718) and the protection panel (12, 14, 114, 214, 314, 112, 218, 318).

12. 12. Optical monitoring system according to claim 10 or 11, characterized in that sensor data of the temperature sensor (2011) can be used to control signals to the ultrasonic transducers (10, 10a-j, 1611, 1612, 1711-1718).

13. 13. Optical surveillance system according to claim 12, characterized in that the amplitude, frequency or pulse width of the signals to the ultrasonic transducers (10, 10a-j, 1611, 1612, 1711-1718) are controllable.

14. Optical monitoring system according to any one of claims 10 to 13, characterized in that the temperature sensor (2011) is an NTC thermistor, a PTC thermistor, a thermistor, a diode and / or a thermocouple.

15. a connecting layer (16) is arranged between the transducers (10, 10a-j, 1611, 1612, 1711-1718) and the protective panels (12, 14, 114, 214, 314, 112, 218, 318); A circuit breaker (2010) and / or a temperature sensor (2011) are embedded in the peripheral area of ​​the connection layer (16). Optical surveillance system according to any one of claims 1 to 14, characterized in that it comprises:

16. Optical surveillance system according to any one of claims 1 to 15, characterized in that the optical surveillance system is embodied as a camera, a laser scanner or any other surveillance optical unit.

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