Dynamic conditioning of a sound emission by vehicle glazing

Abstract

The invention relates to a method for controlling an audio exciter (2) mounted on vehicle glazing in order to make it vibrate to generate an acoustic emission, in which a controller (3) for operating the audio exciter performs the following steps: - receiving a sound sequence (5); - receiving data (4) which are representative of an operating state of the vehicle; - conditioning the sound sequence by applying a calibrated processing operation according to the data representative of a vehicle operating state; - transmitting the conditioned sound sequence to the audio exciter.

Description

Description Title of the invention: Dynamic conditioning of sound emission by vehicle glazing Field of invention

[0001] The field of the invention is that of glazing equipped with audio exciters to transform them into loudspeakers. State of the art

[0002] Surface audio exciters generate sound from a membrane formed by a wall, for example, plaster, glass, or wood. Sound generation is driven by vibrations of the wall on which the exciter is fixedly mounted, via a rigid connection. The system comprising the exciter and the wall thus makes it possible to emit acoustic and vibration waves.

[0003] An example of a sound emission system comprising a vehicle window and an audio exciter mounted on the window is presented in international application WO 2023 / 083883 A1. Statement of the invention

[0004] An objective of the invention is to improve the acoustic performance of such a sound emission system. To this end, the invention proposes a method for controlling an audio exciter mounted on a vehicle window to make it vibrate in order to generate an acoustic emission, comprising the implementation of the following steps by a controller for controlling the audio exciter: - reception of a sound sequence; - reception of data representative of the operating state of the vehicle; - conditioning of the sound sequence by applying a calibrated treatment based on data representative of an operating state of the vehicle; - transmission of the conditioned sound sequence to the audio exciter.

[0005] Some preferred but non-limiting aspects of this method are as follows:

[0006] - data representative of a vehicle operating state are data representative of a rolling speed or acceleration of the vehicle;

[0007] - the processing is further calibrated according to a typology of the sound sequence;

[0008] - the treatment is further calibrated according to a temperature;

[0009] - it further comprises the reception of a vibro-acoustic measurement carried out by at least one sensor mounted on the glazing, the processing being further calibrated according to the vibro-acoustic measurement;

[0010] Preferably, the vibro-acoustic measurement is carried out by several sensors mounted on the glazing and / or positioned in the passenger compartment of the vehicle.

[0011] Thus, the presence of several sensors, notably mounted on the glazing, allows the audio exciter control controller to better control the spatial reproduction of the sound created by the audio exciter mounted on the glazing.

[0012] In an exemplary embodiment, the sound sequence comes from a vibro-acoustic measurement carried out by one or more sensors mounted on the glazing and / or positioned in the passenger compartment of the vehicle.

[0013] According to a characteristic of the invention, the step of conditioning the sound sequence comprises a step of compensating the sound sequence resulting from said measurement by a counter-sound sequence having substantially the same amplitude and being substantially in phase opposition with respect to the sound sequence.

[0014] Preferably, the sensor(s) are positioned at a predetermined distance from one or more audio exciters, in particular on the same glazing.

[0015] Alternatively, the sensor(s) are positioned at a predetermined distance from one or more audio exciters, the sensors and exciters being positioned on the separate glazings.

[0016] The fact that the sensor(s) are positioned at the predetermined distance from one or more audio exciters makes it possible to reduce the saturation of harmonics audible to the human ear and to filter out unwanted noise, while minimizing the power consumption of the audio exciters. In other words, this makes it possible to reduce harmonic distortions of the audio exciters and the excess power consumption of these audio exciters.

[0017] According to an exemplary embodiment, the step of conditioning the sound sequence comprises an optimization of the frequency content and the gain to be applied in real time to the sound sequence, to create via at least two sound sources, in particular via two audio exciters on the glazing, a spatialized sound emission or possibly personalized sound zones in the passenger compartment of the vehicle.

[0018] "Frequency content and gain optimization" involves modifying the spectral content and gain of sound sources in such a way as to virtually move these sound sources in space. This optimization therefore allows for immersive three-dimensional sound effects.

[0019] A "spatialized sound emission" means a sound emission whose sound sources can be located at different locations in space, in particular in the passenger compartment of the vehicle or on the vehicle window.

[0020] Advantageously, the sound sources comprise at least two audio exciters or at least one audio exciter and at least one loudspeaker of the vehicle.

[0021] A “custom sound zone,” such as a sound bubble, is a sound zone in which the audio content is dedicated to the people in that zone.

[0022] According to a characteristic of the invention, during the step of conditioning the sound sequence, the audio exciter control controller is configured to take into account the intelligibility of speech, measurable by an articulation index, which is a function of the spectral characteristics of the sound field inside the passenger compartment of the vehicle and of the psychoacoustic criteria that can be applied to the vibroacoustic measurement of the sensor. The psychoacoustic criteria are representative of the perception of sound or noise by the passengers.

[0023] This allows for the optimization of the quality of oral communications between passengers and passengers and electronic devices capable of receiving and transmitting speech.

[0024] According to a characteristic of the invention, the sensor(s) are configured to measure the sound level inside and / or outside the passenger compartment of the vehicle. Advantageously, the sensor comprises at least one microphone and / or at least one vibration sensor, such as a piezoelectric sensor or an accelerometer.

[0025] According to a characteristic of the invention, the sensor(s) are configured to measure the vibrations of the glazing forming an acoustic membrane, and the vibrations whose amplitudes are the source of parasitic noise, originating both from the vibrations of the vehicle while driving and from all of the exciters mounted on the glazing and / or positioned on the passenger compartment of the vehicle.

[0026] An "acoustic membrane" is a surface that can undergo elastic deformations and whose vibration generates an acoustic emission. This acoustic emission comes from the audio exciter to which the conditioned sound sequence is transmitted.

[0027] According to a characteristic of the invention, the conditioning of the sound sequence comprises a step of separating the vibrations of the glazing forming an acoustic membrane from said vibrations whose amplitudes are the source of parasitic noise.

[0028] - the conditioning of the sound sequence is a shaping by filtering and / or amplification.

[0029] Filtering is applied to equalize the frequency response of the emitted signal according to the noise emitted by the environment. The filtering is done by taking into account the resonance frequencies of the audio exciter, the glazing and / or the passenger compartment of the vehicle. Thus, the step of conditioning the sound sequence makes it possible to effectively reduce the resonances specific to the system comprising the audio exciter mounted on the glazing and to the passenger compartment of the vehicle, so as to reduce or even eliminate any "coloration" in the sound emission. The sound emission is then characterized by a frequency response without marked resonance.

[0030] In a particular embodiment, the filtering can be done using a high-pass filter having a cutoff frequency between 300 Hz and 3400 Hz. This bandwidth, commonly used in telecommunications, ensures the clarity and intelligibility of the voice.

[0031] The signal thus conditioned, emitted by the audio exciter, will allow better distinction of voices, such as voices coming from an electronic device (e.g. GPS) or telephone communications in a deaf environment, i.e. in a vehicle interior where low-frequency noises such as rolling noise or engine noise, particularly thermal noise, are predominant.

[0032] The invention also relates to a controller for controlling an audio exciter, configured to implement the steps of the method according to the invention as well as a computer program product comprising instructions which, when the program is executed by a computer, lead the latter to implement this method.

[0033] The invention extends to a sound emission system comprising: - a first vehicle glazing; - at least one audio exciter mounted on the first glazing; - a controller for controlling at least one audio exciter according to the invention.

[0034] Such a sound emission system may comprise several audio exciters mounted on the first glazing, the controller being configured to condition differently the sound sequence transmitted to each of the audio exciters.

[0035] Such a sound emission system may further comprise a second vehicle glazing and at least one audio exciter mounted on the second glazing, the controller being further configured to control the at least one audio exciter mounted on the second glazing and to condition differently the sound sequence transmitted to the at least one audio exciter mounted on the first glazing and the sound sequence transmitted to the at least one audio exciter mounted on the second glazing.

[0036] According to a characteristic of the invention, the audio exciter may be a piezoelectric audio exciter or an electrodynamic audio exciter (or an inertia exciter). The audio exciter may be overmolded with the glazing, in particular laminated.

[0037] According to a characteristic of the invention, the sensor(s) may be overmolded with the glazing, in particular laminated glazing.

[0038] According to a characteristic of the invention, the glazing is laminated glazing. The laminated glazing comprises at least two sheets of glass between which is inserted an interlayer film, in particular made of viscoelastic plastic material, for example poly(vinyl butyral) (PVB).

[0039] Alternatively, the glazing is single glazing, consisting of a single sheet of glass. Description of figures

[0040] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0041] [Fig.1] - Figure 1 is a diagram showing a vehicle window equipped with an audio exciter;

[0042] [Fig.2] - Figure 2 is a diagram illustrating a processing chain for a sound sequence which can be implemented in a possible embodiment of the invention using the glazing of Figure 1;

[0043] [Fig.3] - Figure 3 is a diagram showing a vehicle window equipped with an audio exciter and a vibro-acoustic sensor;

[0044] [Fig.4] - Figure 4 is a diagram illustrating a processing chain for a sound sequence which can be implemented in a possible embodiment of the invention using the glazing of Figure 3.

[0045] Throughout the figures, similar elements have identical references. Detailed description of the invention

[0046] With reference to Figures 1 and 3, a vehicle glazing 1 is adapted to produce an acoustic emission. To do this, the glazing 1 is equipped with an audio exciter 2. The audio exciter 2 makes it possible to vibrate the glazing 1, this vibration generating an acoustic emission.

[0047] The glazing 1 may take the form of a glazed assembly which comprises at least one glass sheet. The glazed assembly may comprise a glass sheet or form a laminated glazing comprising at least two glass sheets between which an interlayer of viscoelastic material is arranged. The glass sheet(s) 13 may be made of organic or mineral glass, for example tempered glass.

[0048] The glass assembly may be transparent or opaque. The glass assembly may include an opaque coating. The opaque coating may be a paint or enamel, for example black. The glazed assembly may include a transparent glazed portion and an opaque glazed portion. The opaque glazed portion may surround the transparent glazed portion. The glazed assembly may be tinted throughout, over all or part of the surface of the glazed assembly.

[0049] By using laminated glazing with a layer of viscoelastic material inserted between two sheets of glass, the acoustic transmission of glazing 1 is more homogeneous in the acoustic emission spectrum than for glazing 1 comprising only one sheet of glass.

[0050] The interlayer of viscoelastic material may comprise one or more layers of a viscoelastic polymer such as polyvinyl butyral (PVB) or an ethylene-vinyl acetate copolymer (EVA). The interlayer is preferably made of acoustic PVB (such as single-layer or tri-layer acoustic PVB). The acoustic PVB may comprise three layers: two outer layers of standard PVB and an inner layer of PVB which comprises a plasticizer content higher than the plasticizer content of standard PVB, which makes the inner layer less rigid than the outer layers. The use of acoustic PVB in laminated glazing makes it possible, compared to standard PVB, to improve the reproduction of low frequencies and to reduce vibration problems.

[0051] Glazing 1 is vehicle glazing. In particular, glazing 1 may be selected from a windshield, side glazing, door glazing, rear window, and roof glazing. Glazing 1 may have a rectangular shape or a trapezoidal shape. Glazing 1 may have straight or curved edges.

[0052] The glazing 1 may comprise a single audio exciter or several audio exciters. When several audio exciters are used, these may be used to produce acoustic emission in different frequency ranges. These different frequency ranges may correspond to the frequency ranges of the loudspeakers generally used in vehicles: subwoofer-type loudspeakers whose emission frequency is typically between 20 Hz and 200 Hz, door speakers with a frequency typically between 100 Hz and 300 Hz, tweeters with a frequency typically between 300 Hz and 16 kHz.

[0053] The audio exciter(s) 2 may be piezoelectric audio exciters, electrodynamic audio exciters (or inertial exciters), electrostatic audio exciters or magnetostriction audio exciters.

[0054] With reference to Figures 2 and 4, the invention proposes a method for controlling an audio exciter 2 implemented by a controller 3 for driving the audio exciter. The controller 3 can take the form of a digital signal processor.

[0055] This method comprises the reception, by the controller 3, of data 4 representative of an operating state of the vehicle and of a sound sequence 5 to be reproduced via the glazing 1.

[0056] The data 4 representative of an operating state of the vehicle may be data from measurements taken by sensors or data provided by a central computer of the vehicle. The data representative of an operating state of the vehicle may include data representative of a rolling speed of the vehicle, an acceleration of the vehicle, and / or a temperature of the vehicle, in particular the temperature of the glazing, or the actuation of a vehicle component (such as the air conditioning or ventilation). The data representative of the acceleration of the vehicle may be obtained via a tachometer of the vehicle's engine or via information relating to the actuation of vehicle braking. The data 4 representative of an operating state of the vehicle may also be obtained by an audio recording in the passenger compartment of the vehicle.

[0057] The sound sequence 5 can be provided to the controller 3 via one or more audio sources (FM tuner or multifunction mobile phone for example). The sound sequence can have a particular typology, for example depending on whether it is a telephone call type sound sequence, a radio type sound sequence or a music type sound sequence.

[0058] The method further comprises the conditioning, by the controller 3, of the sound sequence 5 by applying a calibrated processing according to the data 4 representative of the operating state of the vehicle. The method according to the invention thus carries out a dynamic (or adaptive) conditioning of the sound sequence, adapted to the operating state of the vehicle. The conditioning of the sound sequence is typically a shaping of the sound sequence by filtering and / or amplification.

[0059] In a possible embodiment, the processing applied to the sound sequence can also be calibrated according to the typology of the sound sequence 5. For example, for a sound sequence representative of a telephone call, the processing of the sound sequence can be an amplification in a range of medium frequencies, for example between 300 Hz and 5 kHz. Thus, the energy required for the amplification is limited to a frequency range useful for increasing the intelligibility of a telephone communication. In a different manner, for a sound sequence representative of music broadcast in the passenger compartment of the vehicle, the processing can be an amplification of the signal over all the frequencies of the sound sequence.

[0060] The method then comprises the transmission, by the controller, of the conditioned sound sequence to the audio exciter 2, for example via an amplifier 6.

[0061] A first example of dynamic conditioning of the sound sequence performs conditioning that depends on the vehicle's rolling speed. For example, shaping by filtering and amplification of the sound sequence differs depending on the vehicle's rolling speed. This shaping can be defined by adjusting a gain and filtering certain frequencies of the sound sequence. For example, this shaping can be defined by a cutoff frequency of a low-pass filter and by a gain, associated with a range of rolling speeds. As an example, controller 3 performs the dynamic conditioning illustrated in the table below.

[0062] In particular, at low speeds, both the gain and the cut-off frequency are low. This limits the acoustic emission towards the outside of the vehicle in the medium to high frequency bands, whereas this emission could pose privacy protection problems when the glazing is used to relay a sound source linked to the human voice, for example a telephone call.

[0063] Another example of dynamic conditioning takes temperature into account. Indeed, the lower the temperature, the more rigid the laminated glazing is due to the presence of the intermediate layer of viscoelastic material. The rigidity of the laminated glazing leads to a variation in sound emission. Dynamic conditioning of the sound sequence then makes it possible to correct this variation and therefore free the sound emission from the effects of temperature variation.

[0064] With reference to Figures 3 and 4, the method may further comprise the reception, by the controller 3, of a vibro-acoustic measurement carried out by a sensor 7 mounted on the glazing 1 on its internal face on the passenger compartment side or on its external face. This measurement may be subject to an analog-digital conversion by a converter 8. The processing applied to the sound sequence to condition it is in such a case also calibrated according to this vibro-acoustic measurement.

[0065] The method according to the invention allows dynamic conditioning of the sound reproduction which makes it possible to control the sound emission both inside and outside the vehicle. In particular, the invention makes it possible to ensure better protection of personal data. It also makes it possible to improve the quality of the sound emission inside the passenger compartment, by for example by amplifying low frequencies in order to mask existing frequencies of an interior background noise (for example linked to the operation of air conditioning or ventilation), by proposing a sound emission independent of temperature variations, by taking into consideration a typology of the sound sequence or by taking into consideration the rolling speed or acceleration of the vehicle.

[0066] The invention is not limited to the method as previously described but also extends to the controller 3 configured to implement such a method as well as to a computer program product comprising instructions which, when the program is executed by a computer, lead the latter to implement such a method.

[0067] The invention further extends to a sound emission system comprising a first vehicle glazing, at least one audio exciter mounted on the first glazing and a controller according to the invention.

[0068] In one possible embodiment, this system comprises several audio exciters mounted on the first glazing, the controller being configured to condition differently the sound sequence transmitted to each of the audio exciters. For example, as indicated previously, the audio exciters can be used to achieve acoustic emission in different frequency ranges, such as the frequency ranges of loudspeakers generally used in vehicles.

[0069] In another possible embodiment, this system further comprises a second vehicle glazing and at least one audio exciter mounted on the second glazing, the controller being further configured to control the at least one audio exciter mounted on the second glazing and to condition differently the sound sequence transmitted to the at least one audio exciter mounted on the first glazing and the sound sequence transmitted to the at least one audio exciter mounted on the second glazing. This system takes the form of several loudspeakers formed by different glazings (for example roof glazing and door glazing), with conditioning of the sound sequence specific to each loudspeaker.

Claims

Claims

1. Method for controlling an audio exciter (2) mounted on a vehicle window (1) to make it vibrate in order to generate an acoustic emission, comprising the implementation of the following steps by a controller (3) for controlling the audio exciter: - reception of a sound sequence (5); - reception of data (4) representative of an operating state of the vehicle; - conditioning of the sound sequence by applying a calibrated treatment based on data representative of an operating state of the vehicle; - transmission of the conditioned sound sequence to the audio exciter.

2. A method according to claim 1, wherein the data representative of an operating state of the vehicle comprises data representative of a rolling speed and / or an acceleration of the vehicle.

3. Method according to one of claims 1 and 2, in which the processing is further calibrated according to a typology of the sound sequence.

4. Method according to one of claims 1 to 3, in which the treatment is further calibrated according to a temperature.

5. Method according to one of claims 1 to 4, further comprising receiving a vibro-acoustic measurement carried out by at least one sensor (7) mounted on the glazing and in which the treatment is further calibrated as a function of the vibro-acoustic measurement.

6. Method according to one of claims 1 to 5, in which the conditioning of the sound sequence is shaping by filtering and / or amplification.

7. Controller (3) for controlling an audio exciter, configured to implement the steps of the method according to one of claims 1 to 6.

8. Computer program product comprising instructions which, when the program is executed by a computer, cause the latter to implement the method according to one of claims 1 to 6.

9. A sound emission system comprising: - a first vehicle glazing (1); - at least one audio exciter (2) mounted on the first glazing; - a controller (3) for controlling the at least one audio exciter, according to claim 7.

10. A sound transmission system according to claim 9, comprising a plurality of audio exciters mounted on the first glazing and wherein the controller is configured to differently condition the sound sequence transmitted to each of the audio exciters.

11. A sound emission system according to claim 9, further comprising a second vehicle glazing and at least one audio exciter mounted on the second glazing and wherein the controller is further configured to perform the control of the at least one audio exciter mounted on the second glazing and to condition differently the sound sequence transmitted to the at least one audio exciter mounted on the first glazing and the sound sequence transmitted to the at least one audio exciter mounted on the second glazing.

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