DEVICE FOR REDUCING NOISE PRODUCED BY A BRAKING DEVICE
The method and device for braking devices measure and counteract vibrations to reduce noise across all operating conditions, addressing the limitations of existing noise reduction techniques.
Patent Information
- Application Number
- FR2022011719
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-11-10
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2042-11-10
AI Technical Summary
Current braking devices, particularly electromechanical brakes, generate noise due to numerous moving components, and existing noise reduction methods only partially address the issue, leaving noise present in frequency ranges not covered by these solutions.
A method and device that measure vibrations from the braking device, generate a first signal representing these vibrations, and produce a second signal with the same frequency but inverted phase or frequency offset, which is used to create a vibratory wave that combines with the original vibrations to reduce noise amplitude.
The solution effectively reduces noise generated by the braking device across all operating conditions, ensuring continuous noise attenuation regardless of wear or vibration changes over time.
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Abstract
Description
Title of the invention: DEVICE FOR REDUCING NOISE PRODUCED BY A BRAKING DEVICE Technical field
[0001] The invention relates to a method and a device for attenuating noise produced by a braking device. STATE OF THE PRIOR ART
[0002] Current braking devices, in particular electromechanical brakes for motor vehicles, comprise numerous moving components which are likely to generate operating noise.
[0003] This noise can be unpleasant for the vehicle's passengers.
[0004] To reduce this noise, it has been proposed to incorporate noise-absorbing devices into the braking device, made in particular from polymer materials.
[0005] It has also been proposed to adapt the structure of certain parts of the braking device so that they have less significant vibration modes.
[0006] This is particularly the case for covers of the electromechanical drive device, which has stiffening ribs.
[0007] These solutions make it possible to reduce the amplitude of the vibrations of the braking device for certain frequencies only.
[0008] When the braking device is used in frequency ranges not covered by the solutions presented above, the vibrations may be sufficiently significant for the braking device to generate noise.
[0009] The aim of the invention is to propose a method for reducing the noise produced by the braking device, for any operating condition thereof. Statement of the invention
[0010] The subject of the invention is a method for attenuating the noise generated by a braking device comprising
[0011] a phase of measuring vibrations generated by the braking device,
[0012] a phase of producing a first signal corresponding to said vibrations generated by the braking device,
[0013] a phase of producing a second signal which, added to the first signal, forms a resulting signal of lesser amplitude than the amplitude of the first signal,
[0014] a phase of generating a vibratory wave corresponding to the second signal. The production of a vibratory wave in addition to that generated by the braking device makes it possible to produce a total wave which is of lesser amplitude than that produced by the braking device. The noise thus generated is consequently less loud.
[0015] Preferably, the second signal is a signal having the same frequency and an inverted phase relative to the first signal.
[0016] Preferably, the second signal is a signal having a frequency offset relative to the first signal.
[0017] Preferably, the method is carried out continuously during operation of the braking device.
[0018] The invention also relates to a device for attenuating the noise produced by a braking device, which is capable of implementing a method according to the invention, which comprises a member for measuring vibrations produced by the braking device, an electronic control unit which is capable of producing an attenuation signal in response to a measurement signal produced by the vibration measuring member and a vibration generation device capable of producing a vibratory wave as a function of the attenuation signal produced.
[0019] Preferably, the vibration measuring member comprises a microphone capable of producing a measurement signal as a function of sound waves produced by the braking device.
[0020] Preferably, the attenuation vibration generating device is a loudspeaker intended to produce an attenuation sound.
[0021] Preferably, the vibration generating device comprises a vibrating element capable of producing vibrations on the brake.
[0022] Preferably, the attenuation device is capable of implementing a noise attenuation method according to the invention. Brief description of the drawings
[0023] [Fig. 1] is a schematic representation of a first embodiment of an attenuation device according to the invention.
[0024] [Fig.2] is a schematic representation of a second embodiment of an attenuation device according to the invention. DETAILED DESCRIPTION OF THE INVENTION
[0025] Figures 1 and 2 show two examples of embodiments of a device 10 for attenuating sound waves 12 generated by a braking device (not shown), preferably an electromechanical braking device.
[0026] As previously stated, the sound waves, or noise, generated by the braking device result from the accumulation of vibrations of various components of the braking device.
[0027] The attenuation device 10 comprises a first component 14 for acquiring and / or measuring the vibrations produced by the braking device.
[0028] Preferably, this first component 14 is a microphone sensitive at least to the frequencies that it is proposed to suppress or attenuate. It is by this microphone that the amplitude and the frequency of the sound waves 12 are measured.
[0029] The first component 14 produces a first electrical signal 16 representative of these sound waves 12. This electrical signal is typically an analog signal which is advantageously amplified and digitized if necessary, then transmitted to an electronic control box 18 or ECU (for Electronic Control Unit).
[0030] The electronic control box 18 in turn produces a second electrical signal 20 typically in phase opposition with the signal to be suppressed which is transmitted to a vibration generation device 22. Typically, this second electrical signal 20 is a digital signal which is in phase opposition with the first electrical signal 16 representative of the sound waves 12.
[0031] This electrical digital signal generated by the electronic control box 18 is converted into an analog signal and then amplified to reach an amplitude optimizing the attenuation of the noise to be suppressed.
[0032] These vibrations generated by the vibration generating device 22 combine with those produced by the braking device to produce a total vibration of lesser amplitude, therefore producing less noise.
[0033] According to the embodiment shown in [Fig. 1], the vibration generating device 22 consists of a loudspeaker, which produces a sound wave adding to the sound waves 12 to produce a smaller resulting sound wave.
[0034] According to the embodiment shown in [Fig.2], the vibration generating device 22 consists of a vibrating element which is mounted on the braking device. The vibration generating device 22, which produces a vibration wave which adds to the vibrations of the braking device, so that the braking device produces a less significant resulting sound wave.
[0035] According to a first embodiment, the second electrical signal 20 produced by the electronic control unit 18 is a signal having the same frequency but whose phase is inverted relative to the first signal 16, representative of the sound waves 12 produced by the braking device.
[0036] According to a second embodiment, the second electrical signal 20 produced by the electronic control unit 18 is a signal having the same frequency and whose phase is shifted relative to the first signal 16, representative of the sound waves 12 produced by the braking device.
[0037] The attenuation device 10 is thus capable of implementing a method of attenuating the noise generated by the braking device which will be described later.
[0038] In a first phase of the method, the vibrations produced by the braking device are measured. This first phase is implemented by the first component 14 and preferably consists of measuring the sound waves 12 produced by the braking device.
[0039] In a second phase of the method, the first component produces the first signal 16, corresponding to the vibrations, or to the sound waves 12, generated by the braking device.
[0040] In a third phase of the method, the electronic control box 18 produces the second signal 20.
[0041] As stated previously, the second signal 20 produced by the electronic control unit 18 is either a signal having the same frequency but whose phase is inverted relative to the first signal 16, representative of the sound waves 12 produced by the braking device, or a signal having the same frequency and whose phase is shifted relative to the first signal 16, representative of the sound waves 12 produced by the braking device.
[0042] In a fourth phase, a vibration wave is produced. This vibration wave corresponds to the second signal and is produced by the vibration generating device 22.
[0043] As shown in [Fig.l], the vibration generating device 22 may be a loudspeaker. As shown in [Fig.2], the vibration generating device 22 consists of a vibrating element.
[0044] According to a preferred aspect of the invention, the attenuation method is implemented continuously during operation of the braking device.
[0045] This makes it possible to reduce noise regardless of the operating conditions of the braking device, in particular the wear conditions of the friction parts, the vibration properties of which can vary over time.
[0046] Advantageously, as illustrated in the figures, the device according to the invention operates in a closed loop, that is to say that the sound background measured by the first component 14 is an attenuated sound wave corresponding to the superposition of the sound wave resulting from the vibrations generated by the braking device with the sound background produced by the vibration generation device 22.
[0047] It should be noted that the acquisition and processing speed of the device according to the invention is sufficient to not introduce an audible or annoying phase delay between the vibrations 12 and the attenuation signal 20.
[0048] NOMENCLATURE:
[0049] 10: attenuation device
[0050] 12: sound waves
[0051] 14: first component
[0052] 16: measurement signal
[0053] 18: electronic control box
[0054]
[0055] 20: attenuation signal 22: vibration generation device
Claims
Claims
1. A method for attenuating noise generated by an electromechanical braking device, implemented continuously during operation of the electromechanical braking device, the attenuation method comprising: a phase of measuring vibrations (12) generated by the electromechanical braking device, a phase of producing a first signal (16) corresponding to said vibrations (12) generated by the electromechanical braking device, a phase of producing a second signal (20) which, added to the first signal (16), forms a resulting signal of lesser amplitude than the amplitude of the first signal (16), a phase of generating a vibration wave corresponding to the second signal (20), in which the phase of producing the first signal (16) consists of producing a measurement signal (16) as a function of sound waves (12) produced by the electromechanical braking device,and vibration background generated during the generation phase consists of an attenuation sound.,
2. Method according to claim 1, characterized in that the second signal (20) is a signal having the same frequency and an inverted phase with respect to the first signal (16).
3. Method according to claim 1, characterized in that the second signal (20) is a signal having a frequency offset relative to the first signal (16).
4. A device (10) for attenuating noise produced by an electromechanical braking device, which comprises a vibration measuring member (14) produced by the electromechanical braking device, an electronic control unit (18) which is capable of producing an attenuation signal (20) in response to a measurement signal (16) produced by the vibration measuring member (14) and a vibration generating device (22) capable of producing a vibration wave as a function of the attenuation signal produced, in which the vibration measuring member (14) comprises a microphone capable of producing a measurement signal (16) as a function of sound waves (12) produced by the electromechanical braking device, and wherein the attenuating vibration generating device (22) is a loudspeaker intended to produce an attenuating sound.
5. 5. Attenuation device (10) according to claim 4, characterized in that the vibration generating device (22) comprises a vibrating element capable of producing vibrations on the brake.
6. Attenuation device (10) according to claim 4 or 5, characterized in that it is capable of implementing a noise attenuation method according to any one of the preceding claims.