DEVICE FOR DETECTING AIRBORNE SOUND FOR AUTOMOTIVE APPLICATIONS, METHOD FOR THE PRODUCTION THEREOF, AND AUTOMATED DRIVING SYSTEM COMPRISING SUCH A DEVICE

Abstract

A device for detecting airborne sound for use in automobiles may include an acoustic sensor, a protective screen for protecting the device against the ingress of coarse foreign matter, an acoustically permeable, hydrophobic and/or lipophobic first membrane, which is placed behind the protective screen in the airflow direction such that when a stream of water enters the opening, the water flows past the first membrane and out of the opening, a sound chamber parallel to the axial axis, wherein a length of the sound chamber is less than 10 mm, preferably less than 6 mm, particularly preferably less than 3 mm, and a printed circuit board comprising components and their connections for preprocessing analog or digital signals from the acoustic sensor, and wherein the acoustic sensor is located on one side of the printed circuit board.

Claims

1. A device for detecting airborne sound for use in an automobile, wherein there are airflows between the device and a sound source, the device comprising: an acoustic sensor, a protective screen for protecting the device against the ingress of coarse foreign matter, wherein the protective screen comprises at least one opening through which the airborne sound enters the device, wherein the opening is offset axially to an axial axis of the device; a first membrane, which is placed behind the protective screen in the airflow direction such that when a stream of water enters the opening, the water flows past the first membrane and back out of the opening; a sound chamber parallel to the axial axis, wherein on a first end of the sound chamber, the first membrane is located in the airflow direction, wherein the acoustic sensor is located at a second end of the sound chamber, wherein the sound chamber is protected by the first membrane against the effects of moisture and foreign matter, wherein a length of the sound chamber is less than 10 mm, and wherein at least one of a diameter, length, volume, shape and material property of the sound chamber are selected such that characteristic modes of the device are greater than 8 kHz; and a printed circuit board, wherein at least one component of the printed circuit board configured for preprocessing analog or digital signals from the acoustic sensor is also configured for at least one of analog or digital signal processing, filtering, phase reversal, compression, and amplification, and wherein the acoustic sensor on one side of the printed circuit board.

2. The device according to claim 1, wherein the acoustic sensor comprises a microphone, which comprises a microphone capsule and a converter.

3. The device according to claim 1, wherein the shape and/or material properties of the protective screen are configured to protect the first membrane, the sound channel and/or the acoustic sensor against dynamic and/or stationary forces.

4. The device according to claim 1, wherein the printed circuit board comprises a plug-in connection for connecting the device to an electronic control unit, and wherein the control unit is designed to locate and/or classify the sound source based on the signal from the acoustic sensor.

5. The device according to claim 1, comprising an elastic seal for coupling the acoustic sensor to the sound chamber and/or the printed circuit board.

6. The device according to claim 1, comprising a decoupling component for dampening vibrations and/or decoupling structure-borne sounds, wherein the decoupling component is made from a two-component material, which generates an acoustic and/or vibrational impedance difference.

7. The device according to claim 1, comprising a second membrane for ventilating the device.

8. (canceled)

9. (canceled)

10. (canceled)

11. (canceled)

12. The device according to claim 1, wherein the first membrane is acoustically permeable.

13. The device according to claim 1, wherein the first membrane is hydrophobic.

14. The device according to claim 1, wherein the first membrane is lipophobic.

15. The device according to claim 1, wherein the length of the sound chamber is less than 6 mm.

16. The device according to claim 1, wherein the length of the sound chamber is less than 3 mm.

17. The device according to claim 1, wherein the characteristic modes of the device are greater than 10 kHz.

18. A method, comprising: assembling a device for detecting airborne sound for use in automobile wherein there are airflows between the device and a sound source, the device comprising: an acoustic sensor, a protective screen for protecting the device against the ingress of coarse foreign matter, wherein the protective screen comprises at least one opening through which the airborne sound enters the device, wherein the opening is offset axially to an axial axis of the device; a first membrane, which is placed behind the protective screen in the airflow direction such that when a stream of water enters the opening, the water flows past the first membrane and back out of the opening; a sound chamber parallel to the axial axis, wherein on a first end of the sound chamber, the first membrane is located in the airflow direction, wherein the acoustic sensor is located at a second end of the sound chamber, wherein the sound chamber is protected by the first membrane against the effects of moisture and foreign matter, wherein a length of the sound chamber is less than 10 mm, and wherein at least one of a diameter, length, volume, shape and material property of the sound chamber are selected such that characteristic modes of the device are greater than 8 kHz; and a printed circuit board, wherein at least one component of the printed circuit board configured for preprocessing analog or digital signals from the acoustic sensor is also configured for at least one of analog or digital signal processing, filtering, phase reversal, compression, and amplification, and wherein the acoustic sensor on one side of the printed circuit board.

19. The method according to claim 18, wherein the acoustic sensor comprises a microphone, which comprises a microphone capsule and a converter.

20. The method according to claim 18, wherein the shape and/or material properties of the protective screen are configured to protect the first membrane, the sound channel and/or the acoustic sensor against dynamic and/or stationary forces.

21. The method according to claim 18, wherein the printed circuit board comprises a plug-in connection for connecting the device to an electronic control unit, and wherein the control unit is designed to locate and/or classify the sound source based on the signal from the acoustic sensor.

22. The method according to claim 18, the device comprising an elastic seal for coupling the acoustic sensor to the sound chamber and/or the printed circuit board.

23. The method according to claim 18, the device comprising a decoupling component for dampening vibrations and/or decoupling structure-borne sounds, wherein the decoupling component is made from a two-component material, which generates an acoustic and/or vibrational impedance difference.

24. The method according to claim 18, the device comprising a second membrane for ventilating the device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Certain aspects shall be explained below in reference to the drawings. Therein:

[0053] FIG. 1 shows a perspective view of an exemplary embodiment of the device according to the invention;

[0054] FIG. 2 shows a first cutaway view of the exemplary embodiment shown in FIG. 1;

[0055] FIG. 3 shows a second cutaway view of the exemplary embodiment shown in FIG. 1;

[0056] FIG. 4 shows an exemplary embodiment of an automated vehicle according to the invention;

[0057] FIG. 5 shows an exemplary embodiment of an outside of the vehicle shown in FIG. 4; and

[0058] FIG. 6 shows an exemplary embodiment of the method according to the invention.

[0059] Identical reference numerals indicate the same or functionally similar parts in the drawings. For purposes of clarity, only those parts that are relevant are indicated in the individual figures.

DETAILED DESCRIPTION OF THE DRAWINGS

[0060] In FIGS. 1, 2 and 3, a printed circuit board L is placed in a device AKS, such that it is perpendicular to an axial axis A of the device AKS.

[0061] The device AKS comprises a component B. The component B supports the device AKS on the outside K of a vehicle F, as shown in FIGS. 4 and 5. The component B is an injection molded part, for example, or a part produced with an additive process, e.g. a 3D printing process. The outside K of the vehicle F is a part of a body of the vehicle F, for example, such as a bumper. The bumper can either be at the front or back of the vehicle.

[0062] The component B has a round hole. A protective screen 2 is placed in this hole. The protective screen 2 is coupled to the component B by a decoupling component 11, as shown in FIGS. 1, 2 and 3. By way of example, the protective screen 2 and the decoupling component 11 are made from an injection molded part. The protective screen 2 in FIGS. 1, 2, and 3 comprises four symmetrically placed slots, three of which slots 3a, 3b, 3c are shown. The openings 3a, 3b, 3c are entry openings in the device AKS for airborne soundwaves. The airborne soundwaves enter the device AKS in the airflow direction R. The openings 3a, 3b, 3c are offset axially to an axial axis A in the device AKS.

[0063] The airborne soundwaves are conducted through a sound chamber 7 to an acoustic sensor 1. The acoustic sensor 1 is placed on the back of the printed circuit board L in the airflow direction R, which is the surface of the printed circuit board L populated with electronic components. A first membrane 5 is placed at the first end E1 of the sound chamber 7. The acoustic sensor 1 is placed in the extension of the second end E2 of the sound chamber 7.

[0064] The acoustic sensor 1 is an electroacoustic sensor, e.g. a microphone. The acoustic sensor 1 in the exemplary embodiments is a MEMS microphone. FIGS. 1, 2, and 3 each show a microphone capsule. The acoustic sensor 1 is coupled to the sound chamber 7 and a printed circuit board L by means of a seal 10.

[0065] The printed circuit board L is in a housing G. The housing G is an electronics housing. The printed circuit board L is populated with components and their connections for preprocessing analog or digital signals from the acoustic sensor 1. The printed circuit board L also has plug-in connections S for connecting the printed circuit board L and therefore the device AKS to an electronic control unit for signal transfer.

[0066] The housing G has two membranes 12 that form ventilation membranes for equalizing the pressure in the housing G and preventing a buildup of condensation in the housing G. The housing G also has fastening means, e.g. threaded fasteners.

[0067] FIG. 3 shows the sound chamber 7 in detail. A first length L1 of the sound chamber 7, in which the sound chamber 7 extends from the first membrane 5 to the acoustic sensor 1, is 5.350 mm. Without the printed circuit board L and without the seal 10, the sound chamber 7 has a second length L2 of 2.700 mm, by way of example. The second length L2 of 2.700 mm is the minimum if a certain housing wall thickness and tolerances when installing the printed circuit board L, as well as the concept with the component B and the protective screen 2, are maintained. In theory, shorter second lengths L2 are possible. The diameter D of the sound chamber 7 is a maximum of 3.915 mm, by way of example. The diameter D is less than 3.915 mm.

[0068] FIG. 4 shows a passenger automobile as an example of a vehicle F. The device AKS is integrated on the outside K of the vehicle F, e.g. in a bumper. The device AKS is held in the bumper by the component B, as shown in FIG. 5. There is also a device AKS in each of the front wheel housings RK in the vehicle F.

[0069] FIG. 6 shows an exemplary sequence for the method. Another aspect involves a different sequence of the individual steps, e.g. V5, V4, V3, V2, V1.

[0070] In step V1, the acoustic sensor 1 is coupled to the printed circuit board L using the seal 10. In step V2, the acoustic sensor 1 is coupled to the second end E2 of the sound chamber 7, which has a smaller second surface by means of the seal 10. In step V3, the first membrane 5 is placed at the first end E1 of the sound chamber 7, which has a larger second surface. In step V4, the protective screen 2 is placed in the decoupling component 11. In step V5, the housing obtained in this manner, i.e. the device AKS, is placed in the component B, in which the housing can be installed and/or with which the housing can be mechanically supported.

REFERENCE SYMBOLS

[0071] 1 acoustic sensor [0072] 2 protective screen [0073] 3a opening [0074] 3b opening [0075] 3c opening [0076] 4 printed circuit board hole [0077] 5 first membrane [0078] 7 sound chamber [0079] L1 first length [0080] L2 second length [0081] D diameter [0082] 10 seal [0083] 11 decoupling component [0084] 12 second membrane [0085] E1 first end [0086] E2 second end [0087] AKS device [0088] A axial axis [0089] R airflow direction [0090] L printed circuit board [0091] S plug-in connection [0092] G housing [0093] B component [0094] V1-V5 steps of the method [0095] F vehicle [0096] RK wheel housing [0097] K outside