Device for detecting airborne sound for automotive applications, method for the production thereof, and automated driving system comprising such a device

Abstract

The invention relates to a device (AKS) for detecting airborne sound for automotive applications, comprising: an acoustic sensor (1); a protective grating (2) for securing the device (AKS) against penetration of coarser foreign bodies; an acoustically permeable, hydrophobic and / or lipophobic first diaphragm (5) which is located downstream of the protective grating (2) in the airflow direction (R) such that, under the action of jets of water into the opening (3a, 3b, 3c), the jets of water flow past the first diaphragm (5) and back out of the opening (3a, 3b, 3c); a sound channel (7) located in parallel with the axial axis (A), a length of the sound channel (7) being smaller than 10 mm, preferably smaller than 6 mm, particularly preferably smaller than 3 mm; and a circuit board (L) comprising components and the connections thereof for preprocessing analogue or digital signals of the acoustic sensor (1), the acoustic sensor (1) being located on one side of the circuit board (L).

Description

[0001] The invention relates to a device for detecting airborne sound for automotive applications according to claim 1, a method for manufacturing it according to claim 8, and an automated driving system comprising such a device.

[0002] Acoustic sensors for detecting external noises outside of vehicles are known in the prior art. For example, DE 10 2016 006 802 A1 discloses a method and a device for detecting at least one special signal emanating from an emergency vehicle.

[0003] German patent application number 10 2019 206 331.4 discloses a device for detecting airborne sound for automotive applications, comprising a flow bypass that runs between a protective grille and a first diaphragm of the device. The flow bypass directs fluids and / or foreign particles that have entered the device via the airflow away from the first diaphragm and out of the device. A sound channel of the device and the flow bypass are implemented by an inflow element. The inflow element includes a bulge. The bulge comprises a cavity extending along the axial axis through which the sound channel is implemented. The inflow element is joined to the protective grille in such a way that the flow bypass is implemented through a free space between the inflow element and the protective grille. That is, the flow bypass runs between the protective grille and the inflow element.

[0004] German patent DE 10 2019 206 329 A1 discloses a device for measuring the noise levels of a road vehicle in road traffic. This device also includes a flow bypass.

[0005] The invention was made in view of the realization that the flow bypass causes very high wind noise and, when used in a driving system, is only usable up to a driving system speed of essentially 50 km / h.

[0006] The object of the invention was to provide a device for detecting airborne sound for automotive applications that was improved compared to the prior art, in particular a device in which wind noise does not dominate even at high speeds of the driving system.

[0007] The following definitions and further explanations apply to the entire subject matter of the invention.

[0008] The device according to the invention detects airborne sound for automotive applications where airflows are present between the device and a sound source. The device achieves this through a system property resulting from the targeted coordination of individual components. The device comprises an acoustic sensor. Furthermore, the device includes a protective grille to safeguard it against the ingress of larger foreign objects. The protective grille has at least one opening for the airborne sound to enter the device. This opening is axially offset from an axial axis of the device. The device also includes an acoustically permeable, hydrophobic, and / or lipophobic first membrane.The first membrane is arranged behind the protective grille in the direction of airflow such that when water jets enter the opening, the water jets flow back out of the opening past the first membrane. The device also includes a sound channel arranged parallel to the axial axis, at one end of which, in the direction of airflow, the first membrane is arranged, and at the other end of which the acoustic sensor is arranged. The sound channel is protected against the effects of moisture and foreign matter by the first membrane. Compared to the sound channel of the device disclosed in German application no. 10 2019 206 331.4, the length of the sound channel of the device according to the invention is shorter. According to the invention, the length of the sound channel is less than 10 mm, preferably less than 6 mm, and particularly preferably less than 3 mm.The diameter, length, volume, shape, and / or material properties of the sound channel are adapted such that the device's natural modes are greater than 8 kHz, preferably greater than 10 kHz. The device also includes a printed circuit board (PCB). The PCB comprises components and their connections for preprocessing analog or digital signals from the acoustic sensor. The components are designed for analog or digital signal processing and / or for implementing filter functions, phase inversion functions, compressor functions, and / or amplifier functions. Furthermore, the PCB includes the acoustic sensor on one side. The device according to the invention is designed without a flow bypass.

[0009] For example, the acoustic sensor is located on the rear side of the circuit board (in the direction of airflow). In this case, the acoustic sensor's sound inlet is on the component mounting side of the circuit board, and the circuit board includes a sound inlet opening. Alternatively, the acoustic sensor is located on the front side of the circuit board (in the direction of airflow). In this case, the acoustic sensor's sound inlet is on the side of the acoustic sensor opposite the component mounting side of the circuit board.

[0010] The special feature of the device according to the invention compared to known microphones is its functionality and ability to detect and convert airborne sound under the challenging environmental and flow conditions found in automotive applications. For example, during the movement of a vehicle, a speed-dependent airflow is generated, resulting in relative air currents at the device. The device according to the invention is characterized by its ability to detect and convert airborne sound under these relative air currents. Due to the system properties resulting from the targeted tuning of individual components, the device according to the invention can be used in various environmental conditions, for example, under external influences such as rainwater, or under flow conditions caused by wind, such as the wind generated by driving. Simultaneously, the device according to the invention minimizes the attenuation of the external acoustic signal.The environmental conditions arise, firstly, from the use of the acoustic sensor in automotive applications, for example, in road traffic. Secondly, the environmental conditions result from the installation locations of the acoustic sensors, which are located on moving and / or stationary, weather-exposed, so-called open-air objects, for example, on vehicles. These conditions include, for example, water, jet water, muddy water, snow, ice, dust, salts (e.g., road salt), high and / or low ambient temperatures, high or low humidity, and / or higher relative air currents, such as those present during a vehicle journey. The device according to the invention can detect airborne sound and convert it into electrical signals within a temperature range of -50°C to +90°C, for example, -30°C to +70°C.The device according to the invention is characterized in that the individual components of the device, for example the acoustic sensor, the protective grille, the opening for the airborne sound inlet, i.e. the sound inlet opening, the first membrane, and the sound channel, are coordinated with each other, taking into account airborne and / or structure-borne sound, aeroacoustics, flow and fluid dynamics, electronics and mechanics.

[0011] The shortened sound channel has the advantage that, according to one aspect of the invention, the device's natural modes lie above 8 kHz and are relatively indistinct, for example, only + / - 5 dB compared to up to + / - 40 dB with a longer sound channel. With longer sound channels, strong resonances of up to + / - 40 dB are generated at approximately 5 kHz, rendering the acoustic signal to be captured and evaluated unusable in certain cases. Thus, the shortened sound channel improves the usability of the acoustic signal.

[0012] The flow bypass of the device disclosed in the German patent application number 10 2019 206 331.4 causes very high wind noise because air flows through the bypass. Eliminating the flow bypass drastically reduces the wind noise. The device with the flow bypass was only usable up to a speed of approximately 50 km / h. The device according to the invention, with its shortened sound channel, can detect acoustic signals even above 100 km / h without wind noise becoming dominant.

[0013] In the device according to the invention, jet water is flushed past the first membrane and back forward. This creates a higher water flow in front of the first membrane, which has a cleaning effect. The forces acting on the first membrane are kept low by the direction of the water flow.

[0014] The device provides a housing for the acoustic sensor. The term acoustic sensor refers both to the acoustic sensor as a component of the device and to the device as a whole.

[0015] An acoustic sensor is a sensor that detects mechanical vibrations, for example, those caused by sound waves in the air, and converts them into a processable signal, such as an electrical signal like a voltage. The acoustic sensor includes an analog and / or digital signal output. The conversion takes place in two stages. In the first acoustic-mechanical conversion stage, the sound waves are converted into the movement of an object according to a specific receiver principle. In the second mechanical-electrical conversion stage, the object's movement is converted into the electrical signal according to a specific transducer principle. Examples of acoustic sensors include arrangements of a magnet and an electrical coil, microphones, accelerometers, piezoelectric transducers, and strain gauges.A micro-electro-mechanical system, abbreviated MEMS, comprising an arrangement of semiconductor elements that detect vibrations, can also be used as an acoustic sensor.

[0016] The protective grille is a grid with a mechanical protective function. The protective grille is designed so that larger foreign bodies, i.e., particles with diameters of, for example, at least 2 mm, such as dirt particles like mud particles, dust particles, soot particles, salt grains, stones, insects, or other particles contained in the air, cannot penetrate the device.

[0017] The opening for the air inlet is positioned in the protective grille such that no direct beam and / or particle stream acts on the first membrane in the axial sensor direction. Thus, the first membrane is mechanically protected by the arrangement and / or geometry of the opening. According to one aspect of the invention, the opening or openings are essentially 2 mm wide and essentially 5 mm long.

[0018] The first membrane is permeable to airborne sound waves. Due to its hydrophobic and / or lipophobic properties, the sound channel is protected against ingress of, for example, moisture and particles. According to another aspect of the invention, the first membrane is a microporous membrane. A membrane with, for example, 1.3 x 10⁹ pores / cm² is considered microporous. Such a membrane is particularly waterproof and provides protection at least to IPX4K. According to another aspect of the invention, the first membrane is designed to provide protection to IP69K. The number 6 in IP69K signifies complete impermeability and thus protection against the ingress of solids and dust. 9K denotes protection against the ingress of water during high-pressure or steam jet cleaning. This is particularly advantageous for protection in automotive applications.

[0019] The protection rating indicates the suitability of components for various environmental conditions. The protected systems are classified into corresponding protection ratings, known as International Protection, abbreviated IP codes. The standard ISO 20653:2013 Road vehicles - Degrees of protection (IP code) - Protection against foreign objects, water and contact - Electrical equipment describes the standard for road vehicles. IP6XK offers protection against powerful water jets under increased pressure, specifically for vehicle systems.

[0020] Airflow direction means the direction of airflow through the device or the direction of airflow relative to the vehicle system on which the device is installed. With respect to the airflow direction relative to the vehicle system, if the device is rear-mounted and the protective grille is open in the opposite direction to the forward travel of the vehicle system, the roles of the first end and the second end of the sound duct are reversed.

[0021] The sound channel serves to guide airborne sound waves precisely to the acoustic sensor. The sound channel is acoustically dimensioned to minimize or eliminate weak natural modes within the usable frequency range of the acoustic sensor. This targeted dimensioning is primarily based on the reduced length and diameter, volume, and shape.

[0022] The printed circuit board (PCB) is also called a circuit board or printed circuit board. The components on the PCB include, for example, logic devices such as ASICs or FPGAs. For instance, one component implements a high-pass filter that allows airborne sound waves with frequencies above 300 Hz to pass through. Compressor functions are used to limit the dynamic range of a signal. The components are mounted directly onto the surface of the PCB, for example, by soldering, and are also called surface-mount devices (SMDs). The PCB opening corresponds to a hole or through-hole on the PCB for airborne sound to enter the acoustic sensor, which is located on the side of the PCB facing away from the airflow. The side facing away from the airflow is the surface of the PCB on which the components and the acoustic sensor are located.With respect to the airflow direction relative to the driving system, in the case of a rear-mounted device where the protective grille is open against the forward direction of travel of the driving system, the front side of the circuit board in the direction of airflow is the surface of the circuit board on which the components and the acoustic sensor are arranged.

[0023] According to one aspect of the invention, the acoustic sensor comprises a microphone, for example, a MEMS microphone. The microphone comprises a microphone capsule and a transducer. The acoustic-mechanical conversion takes place in the microphone capsule. The microphone capsule comprises, for example, a diaphragm that is excited to vibrate by sound waves in the air. The mechanical-electrical conversion takes place in the transducer. The transducer is, for example, an electrodynamic transducer, such as in a moving-coil microphone, or an electrostatic transducer, such as in a condenser microphone.

[0024] According to a further aspect of the invention, the shape and / or material properties of the protective grille are adapted to protect the first membrane, the sound channel, and / or the acoustic sensor against fluid dynamic and / or static forces, such as those caused by wind or weather. The protective grille and its openings are, for example, rotationally symmetrical. The protective grille is, for example, made of a plastic and is shaped, i.e., has a geometry such as, to provide a level of protection of at least IP6XK. This achieves mechanical protection of the device and protects the acoustic sensor against such influences.

[0025] For example, the protective mesh incorporates an open-cell material, such as a foam material like open-cell polyurethane foam. Wind and / or water absorption can be adjusted by varying the pore size within the material. Foam materials are characterized by their very low density and ease of processing and manipulation. Polyurethane foams are particularly easy to produce. Open-cell polyurethane foam is also known as filter foam. Filter foam is especially well-suited for wind absorption. Filter foam is classified according to pore size / number of pores. The unit of measurement is the number of pores per inch, abbreviated PPI. For example, the protective mesh incorporates a filter foam with a PPI ranging from 10 to 80.

[0026] According to another aspect of the invention, the protective grille is a replaceable protective grille so that it can be replaced in case of heavy soiling without having to replace the entire device.

[0027] According to a further aspect of the invention, the device comprises a housing in which the printed circuit board is arranged. The housing protects the printed circuit board and its components from mechanical and / or thermal influences. The housing includes fastening means, for example screws, for attaching the housing and the device to a control unit or to a driving system.

[0028] According to another aspect of the invention, the circuit board is arranged perpendicular or parallel to the axial axis of the device. With the circuit board arranged parallel to the device, the second end of the sound channel is positioned radially as an extension of a surface of the sound channel. With the circuit board arranged perpendicular to the device, the acoustic sensor, for example, the microphone and / or microphone capsule, is coupled to the sound channel parallel to the axial axis of the device. With the circuit board arranged parallel to the device, the acoustic sensor is coupled to the sound channel perpendicular to the axial axis of the device, i.e., tangentially. The parallel arrangement yields particularly good signals from the acoustic sensor.

[0029] According to another aspect of the invention, the circuit board includes a connector for connecting the device to an electronic control unit. The control unit is configured to locate and / or classify the sound source based on the signals from the acoustic sensor. The electronic control unit is, for example, a control unit that communicates exclusively with the device. That is, the control unit only receives signals from the acoustic sensor and evaluates them. The control unit executes, for example, an intelligent algorithm, such as an artificial neural network trained for sound localization and / or classification, such as a convolutional network. According to another aspect of the invention, the evaluated signals are transmitted via the vehicle's electrical system to other control units of the vehicle system, such as ADAS or AD Domain ECUs, or to actuators of the vehicle system.For example, the device is connected to a CAN bus or an Ethernet bus of the driving system.

[0030] According to a further aspect of the invention, the device comprises an elastic sealing component for coupling the acoustic sensor to the sound channel and / or to the circuit board. The sealing component compensates for geometric tolerances during the assembly of the device. The elasticity ensures a defined decoupling of the acoustic sensor, including the microphone capsule, and / or the circuit board from structure-borne noise. Furthermore, the elasticity ensures an acoustically sealed connection between the sound channel and the microphone capsule.

[0031] According to a further aspect of the invention, the device comprises a decoupling component for vibration damping and / or structure-borne noise decoupling. The decoupling component is arranged at a coupling point between the device and a component into which the device can be installed and / or from which the device can be mechanically secured. The decoupling component is made of a two-component material that generates an acoustically and / or vibrationally effective impedance step. The two-component material comprises a relatively soft material with a relatively low impedance and a relatively hard material with a relatively high impedance. The soft material is arranged in front of the hard material in the direction of airflow. The impedance step is implemented across the entire contact surface of the protective grille and the decoupling component. The decoupling component is, for example, a molded part.According to another aspect of the invention, the protective grille and the decoupling component form a single component. For example, the protective grille and the decoupling component are formed from a single injection-molded part. According to another aspect of the invention, the decoupling component is made of vibration-damping materials of different densities, for example, mixed-cell polyurethane foams. The decoupling component possesses, for example, high mechanical strength and / or good insulating properties. By means of this component, the device is resistant to vibrations and therefore particularly well-suited for automotive applications.

[0032] According to a further aspect of the invention, the device includes a second diaphragm for venting the device. The second diaphragm provides static pressure equalization for the device. When the device is mounted on the outside of a driving system, the wind generated during travel exerts pressure on the device, for example, on the acoustic sensor. The second diaphragm equalizes this static pressure. Furthermore, the second diaphragm prevents condensation from forming in the device.

[0033] The inventive method for manufacturing a device according to the invention comprises the following process steps: An acoustic sensor according to the invention is coupled to a printed circuit board according to the invention by means of a sealing component according to the invention, the acoustic sensor is coupled to a second end of a sound channel according to the invention with a smaller second area of ​​an inflow component according to the invention by means of the sealing component, a first membrane according to the invention is arranged at a first end of the sound channel with a larger second area, a protective grid according to the invention is inserted into a decoupling component according to the invention, and the housing for the acoustic sensor obtained according to the preceding process steps is inserted into a component according to the invention, into which the housing can be installed and / or from which the housing can be mechanically held.

[0034] According to the inventive method, the device according to the invention is designed to be free of a flow bypass.

[0035] According to the inventive method, the acoustic sensor is coupled to the rear side of the circuit board in the direction of airflow, i.e., the surface of the circuit board on which the electronic components are arranged. According to the invention, the circuit board is arranged perpendicular or parallel to the axial axis of the device. In the parallel arrangement of the circuit board, the second end of the sound channel is arranged in a radial extension of the outer surface of the sound channel.

[0036] According to another aspect of the invention, the housing is mounted relative to a forward direction of travel from the rear into a front bumper of the driving system or from the front into a rear bumper.

[0037] According to another aspect of the invention, the protective grid and the decoupling component are manufactured and provided as a molded part, for example as an injection molded part.

[0038] Another aspect of the invention is a device manufactured according to the inventive method.

[0039] The inventive method makes it possible to install the housing, in particular the housing according to the invention, directly into / onto the driving system during vehicle manufacturing. Advantageously, the method also allows for the efficient retrofitting of an existing vehicle with the housing according to the invention, especially with the housing in which the acoustic sensors are integrated. Thus, the invention also provides a method for assembling retrofit solutions. For this purpose, the housing is pre-assembled according to the method steps and attached to the driving system as a finished housing. According to one aspect of the invention, the housing is installed relative to a forward direction of travel from the rear into a front bumper of the driving system or from the front into a rear bumper.

[0040] The automated driving system according to the invention comprises a device according to the invention, or an arrangement of several such devices, or a device manufactured according to the method according to the invention. According to the invention, the device is designed such that it can be used at several installation positions on the driving system.

[0041] According to one aspect of the invention, the device according to the invention, or an arrangement of several such devices, is arranged in at least one wheel housing of the vehicle system, preferably in wheel housings located at the front relative to the forward direction of travel, and particularly preferably one device in each wheel housing of the vehicle system. The arrangement in the wheel housing allows for particularly good detection of road-related noise, for example, rainwater on the road surface. According to another aspect of the invention, the device according to the invention, or an arrangement of several such devices, can be installed in a front bumper and / or a rear bumper of the vehicle system. According to a further aspect of the invention, the vehicle system comprises the devices according to the invention in the wheel housings and the front and / or rear bumpers of the vehicle system.

[0042] The device is integrated into an outer surface of the driving system, for example in wheel wells and / or bumpers, by means of a component according to the invention, into which the device can be installed and / or by which the device can be mechanically secured. Furthermore, the device is connected to an ADAS or AD Domain ECU of the driving system via a connector according to the invention.

[0043] For example, several devices according to the invention are arranged offset from each other, for example in a circular, rectangular or linear shape.

[0044] For example, the arrangement comprises four devices positioned side by side. Surprisingly, such an arrangement is very well suited for sound recording and relatively easy to obtain.

[0045] The driving system is, for example, a passenger car, a truck, or a people mover. The driving system includes, for example, technical equipment for self-driving, i.e., driverless or fully automated, autonomous driving. The ADAS (advanced driver assistance system) or AD (autonomous driving), Domain ECU (electronic control unit), uses environmental sensors to perceive the vehicle's surroundings, derives a trajectory plan from this, and determines corresponding control signals that are provided to vehicle actuators to control the longitudinal and / or lateral guidance of the driving system. The acoustic sensor of the device according to the invention is an example of an environmental sensor. Other environmental sensors include, for example, optical sensors, such as cameras or lidar, or radar sensors.According to one aspect of the invention, the signals from the acoustic sensor are fused with signals from other environmental sensors to locate and / or classify objects in road traffic.

[0046] The component includes fasteners for attaching the device to the vehicle system. For example, the device is installed relative to the forward direction of travel from the rear into the front bumper of the vehicle system, or from the front into the rear bumper or into the front and / or rear wheel arches. This allows the device to be retrofitted to existing road vehicles. Alternatively, the device can be permanently installed on the outside of the vehicle system, for example, in its body.

[0047] According to a further aspect of the invention, a first arrangement of the devices is located in a front left area of ​​the driving system, a second arrangement of the devices is located in a front right area of ​​the driving system, a third arrangement of the devices is located in a rear left area of ​​the driving system, and / or a fourth arrangement of the devices is located in a rear right area of ​​the driving system, for example, on bumpers and / or in wheel wells. The arrangement corresponds to a specific positioning. This arrangement with four assemblies enables 360° detection of ambient noise. For example, each arrangement comprises four devices arranged side by side.

[0048] According to another aspect of the invention, the device is integrated into a static object of a traffic infrastructure, for example a traffic light pole or a building, by means of the component according to the invention, into which the device can be installed and / or from which the device can be mechanically held.

[0049] The invention is explained by way of example in the following figures. They show: Fig. 1 a perspective view of an embodiment of a device according to the invention, Fig. 2 a first sectional view of the exemplary embodiment from Fig. 1 , Fig. 3 a second sectional view of the embodiment from Fig. 1 , Fig. 4 an embodiment of an automated driving system according to the invention, Fig. 5 an exemplary embodiment of an outer surface of the drive system made of Fig. 4 and Fig. 6 an embodiment of a method according to the invention.

[0050] In the figures, identical reference numbers denote identical or functionally similar parts. For clarity, only the reference parts relevant to the respective understanding are marked in each figure.

[0051] In the Fig. 1 , 2 and 3 In a device AKS according to the invention, a printed circuit board L is arranged perpendicular to an axial axis A of the device AKS.

[0052] The device AKS comprises a component B. The component B holds the device AKS in an outer surface K of a drive system F, see Fig. 4 and Fig. 5 Component B is, for example, an injection-molded part or a component manufactured using an additive process, such as 3D printing. The outer surface K of the driving system F is, for example, a part of the body of the driving system F, such as a bumper. The bumper is either a front bumper or a rear bumper.

[0053] Component B comprises a circular opening. A protective grille 2 according to the invention is inserted into this opening. The protective grille 2 is coupled to component B by means of a decoupling component 11 according to the invention, see figure. Fig. 1 , 2 and 3 For example, the protective grille 2 and the decoupling component 11 are manufactured from a single injection-molded part. In the Fig. 1 , 2 and 3 The protective grille 2 comprises four symmetrically arranged slot-shaped openings, three of which are shown as 3a, 3b, and 3c. Openings 3a, 3b, and 3c are entry points for airborne sound waves into the device AKS. The airborne sound waves enter the device AKS in the direction of airflow R. Openings 3a, 3b, and 3c are arranged axially offset from an axial axis A of the device AKS.

[0054] The sound waves are guided through a sound channel 7 to an acoustic sensor 1. The acoustic sensor 1 is arranged on the rear side of the circuit board L (i.e., the surface of the circuit board L containing the electronic components) in the direction of airflow R. A first diaphragm 5 according to the invention is arranged at the first end E1 of the sound channel 7. The acoustic sensor 1 is arranged in line with the second end E2 of the sound channel 7.

[0055] The acoustic sensor 1 is an electroacoustic sensor, for example a microphone. In the exemplary embodiments, the acoustic sensor 1 is a MEMS microphone. Fig. 1 , 2 and 3 Each shows a microphone capsule. The acoustic sensor 1 is coupled to the sound channel 7 and to a circuit board L by means of a sealing component 10.

[0056] The circuit board L is arranged in a housing G. The housing G is an electronics enclosure. The circuit board L comprises components and their connections for preprocessing analog or digital signals from the acoustic sensor 1. Furthermore, the circuit board L includes connectors S to connect the circuit board L, and thus the device AKS, to an electronic control unit.

[0057] The housing G includes a second membrane 12 designed as a venting membrane for static pressure equalization of the housing G and for preventing condensation within the housing G. The housing G also includes fastening elements, such as screws.

[0058] Fig. 3Figure 1 shows the sound channel 7 in detail. A first length L1 of the sound channel 7, extending from the first diaphragm 5 to the acoustic sensor 1, is, for example, 5.350 mm. Without the circuit board L and without the sealing component 10, the sound channel 7 has a second length L2 of, for example, 2.700 mm. The second length L2 of 2.700 mm is the minimum when maintaining a certain housing wall thickness and tolerances for the installation of the circuit board L, as well as the concept with component B and the protective grille 2. In principle, smaller second lengths L2 are possible. The diameter D of the sound channel 7 is, for example, a maximum of 3.915 mm. Within the scope of the invention, diameters D are smaller than 3.915 mm.

[0059] Fig. 4Figure 1 shows a passenger car as an example of a driving system F. The device AKS according to the invention is integrated into an outer surface K of the driving system F, for example, a bumper. The device AKS is held in the bumper by means of component B, see Figure 2. Fig. 5 Furthermore, in the driving system F, one of the devices AKS according to the invention is arranged in each of the two front wheel arches RK.

[0060] Fig. 6 Figure 1 shows an example sequence of a process according to the invention. Another aspect of the invention is a different sequence of the individual process steps, for example V5, V4, V3, V2, and V1.

[0061] In process step V1, the acoustic sensor 1 is coupled to the circuit board L by means of the sealing component 10. In process step V2, the acoustic sensor 1 is coupled to the second end E2 of the sound channel 7 with a smaller second area by means of the sealing component 10. In process step V3, the first diaphragm 5 is positioned at the first end E1 of the sound channel 7 with a larger second area. In process step V4, the protective grille 2 is inserted into the decoupling component 11. In process step V5, the housing thus obtained, i.e., the device AKS, is inserted into the component B into which the housing can be installed and / or which mechanically supports the housing. Reference sign

[0062] 1 Acoustic sensor 2 Protective grille 3a Opening 3b Opening 3c Opening 4 Circuit board opening 5 First membrane 7 Sound duct L1 First length L2 Second length D Diameter 10 Sealing component 11 Decoupling component 12 Second membrane E1 First end E2 Second end AKS Device A Axial axis R Airflow direction L Circuit board SS Connector connection G Housing B Component V1-V5 Process step F Vehicle system R Wheel arch K Exterior

Claims

1. Device (AKS) for detecting airborne sound for automotive applications in which there are air flows between the device (AKS) and a sound source of the airborne sound, the device (AKS) comprising • an acoustic sensor (1), • a protective grille (2) for protecting the device (AKS) against the ingress of coarser foreign bodies, the protective grille (2) comprising at least one opening (3a, 3b, 3c) for admitting the airborne sound into the device (AKS), the opening (3a, 3b, 3c) being arranged in a manner axially offset from an axial axis (A) of the device (AKS), • an acoustically permeable, hydrophobic and / or lipophobic first membrane (5), which is arranged behind the protective grille (2) in the direction of air flow (R) in such a way that, when jets of water act upon the opening (3a, 3b, 3c), the jets of water flow past the first membrane (5) back out of the opening (3a, 3b, 3c), • a sound channel (7), arranged parallel to the axial axis (A), ∘ at whose first end (E1, E2) in the direction of air flow (R) the first membrane (5) is arranged, ∘ at whose second end (E2, E1) the acoustic sensor (1) is arranged, ∘ the sound channel (7) being protected by the first membrane (5) against the action of moisture and foreign bodies, ∘ a length of the sound channel (7) being less than 10 mm, preferably less than 6 mm, particularly preferably less than 3 mm, and ∘ the diameter, length, volume, shape and / or material properties of the sound channel (7) being adapted such that eigenmodes of the device (AKS) are greater than 8 kHz, preferably greater than 10 kHz, and • a printed circuit board (L) comprising ∘ components and the connections thereof for preprocessing analogue or digital signals of the acoustic sensor (1), the components being designed for analogue or digital signal processing and / or for performing filter functions, functions for phase reversal, compressor functions and / or amplifier functions, and ∘ on one side of the printed circuit board (L), the acoustic sensor (1), and the device (AKS) being in a form devoid of a flow bypass.

2. Device (AKS) according to Claim 1, the acoustic sensor (1) comprising a microphone, the microphone comprising a microphone capsule and a transducer.

3. Device (AKS) according to Claim 1 or 2, a shape and / or material properties of the protective grille (2) being adapted to protect the first membrane (5), the sound channel (7) and / or the acoustic sensor (1) against flow dynamic and / or static forces.

4. Device (AKS) according to one of Claims 1 to 3, the printed circuit board (L) comprising a plug connection (S) for connecting the device to an electronic control unit, the control unit being designed to localize and / or classify the sound source on the basis of the signals of the acoustic sensor (1).

5. Device (AKS) according to one of Claims 1 to 4, comprising an elastic sealing component (10) for coupling the acoustic sensor (1) to the sound channel (7) and / or to the printed circuit board (L).

6. Device (AKS) according to one of Claims 1 to 5, comprising a decoupling component (11) for damping vibrations and / or decoupling structure-borne sound, the decoupling component (11) being arranged at a coupling point between the device (AKS) and a component (B) in which the device (AKS) can be installed and / or that can mechanically hold the device (AKS), the decoupling component (11) being manufactured from a two-component material that generates an impedance mismatch having an acoustic and / or vibrational effect.

7. Device (AKS) according to one of Claims 1 to 6, comprising a second membrane (12) for venting the device (AKS).

8. Method for producing a device (AKS) according to one of the preceding claims, wherein • an elastic sealing component (10) for coupling an acoustic sensor (1) to a sound channel (7) and / or to a printed circuit board (L) is used to couple the acoustic sensor (1) to the printed circuit board (L) (V1), a length of the sound channel being less than 10 mm, • the acoustic sensor (1) is coupled to a second end (E2) of a sound channel (7) by means of the sealing component (10) (V2), • an acoustically permeable, hydrophobic and / or lipophobic first membrane (5) is arranged at a first end (E1) of the sound channel (7) (V3), • a protective grille (2) is used to protect the device (AKS) against the ingress of coarser foreign bodies into a decoupling component (11) for damping vibrations and / or decoupling structure-borne sound, ∘ the protective grille (2) comprising at least one opening (3a, 3b, 3c, 3d) for admitting the airborne sound into the device (AKS), the opening (3a, 3b, 3c, 3d) being arranged in a manner axially offset from an axial axis (A) of the device (AKS), and ∘ the decoupling component (11) being arranged at a coupling point between the device (AKS) and a component (B) in which the device (AKS) can be installed and / or that can mechanically hold the device (AKS), the decoupling component (11) being manufactured from a two-component material that generates an impedance mismatch having an acoustic and / or vibrational effect (V4), • the housing for the acoustic sensor (1) that is obtained according to the preceding steps is inserted into the component (B), in which the housing can be installed and / or which can mechanically hold the housing (V5), and the device (AKS) is formed so as to be devoid of a flow bypass.

9. Automated driving system (F) comprising a device (AKS) or an arrangement of multiple devices (AKS) according to one of Claims 1 to 7, the device (AKS) being integrated in an outer face (K) of the driving system (F) by means of a component (B) in which the device (AKS) can be installed and / or that can mechanically hold the device (AKS), and being connected for signalling purposes to an ADAS or AD Domain ECU of the driving system (F) by means of a plug connection (S).

10. Driving system (F) according to Claim 9, the device (AKS) or an arrangement of multiple such devices (AKS) being arranged in at least one wheel box of the driving system (F), preferably in front wheel boxes in relation to the forward direction, particularly preferably one device in each wheel box of the driving system, and / or being installed in a front bumper and / or a rear bumper of the driving system (F).

11. Driving system (F) according to Claim 9 or 10, a first arrangement of the devices (AKS) being arranged in a front left region of the driving system (F), a second arrangement of the devices (AKS) being arranged in a front right region of the driving system (F), a third arrangement of the devices (AKS) being arranged in a rear left region of the driving system (F) and / or a fourth arrangement of the devices (AKS) being arranged in a rear right region of the driving system (F).

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