FR3161151A1 - Dynamic conditioning of sound emission from vehicle glazing - Google Patents

Abstract

The invention relates to a method for controlling an audio exciter (2) 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 (3) for controlling the audio exciter: receiving a sound sequence (5); receiving data (4) representative of an operating state of the vehicle; conditioning the sound sequence by applying a calibrated processing according to the data representative of an operating state of the vehicle; transmitting the conditioned sound sequence to the audio exciter. Figure for abstract: Figure 2

Description

Dynamic conditioning of a sound emission by vehicle glazing Scope of the invention

The field of invention is that of glazing equipped with audio exciters to transform them into loudspeakers.

State of the art

Surface-mounted audio exciters generate sound from a membrane formed by a wall, such as plaster, glass, or wood. Sound generation is driven by vibrations of the wall to which the exciter is fixed via a rigid connection. The system, comprising the exciter and the wall, thus emits acoustic and vibratory waves.

An example of a sound emission system comprising a vehicle window and an audio exciter mounted on the window is shown in international application WO 2023/083883 A1.

One 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 cause it to vibrate in order to generate an acoustic emission, comprising the implementation of the following steps by a controller for driving the audio exciter:
- reception of a sound sequence;
- receiving data representative of the vehicle's operating state;
- conditioning of the sound sequence by applying a calibrated processing based on data representative of a vehicle's operating state;
- transmission of the conditioned sound sequence to the audio exciter.

Some preferred, but not exhaustive, aspects of this process are as follows:

- data representing a vehicle's operating state are data representing a vehicle's rolling speed or acceleration;

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

- the treatment is also calibrated according to a temperature;

- it also includes the reception of a vibro-acoustic measurement carried out by a sensor mounted on the glazing, the treatment being further calibrated according to the vibro-acoustic measurement;

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

The invention also relates to a control unit for an audio exciter, configured to implement the steps of the process according to the invention, as well as a computer program product comprising instructions which, when the program is executed by a computer, lead the computer to implement this process.

The invention extends to a sound emission system comprising:
- initial vehicle glazing;
- at least one audio exciter mounted on the first pane of glass;
- a control unit for at least one audio exciter according to the invention.

Such a sound emission system may include several audio exciters mounted on the first pane of glass, with the controller configured to condition differently the sound sequence transmitted to each of the audio exciters.

Such a sound emission system may further include a second vehicle window and at least one audio exciter mounted on the second window, the controller further being configured to drive at least one audio exciter mounted on the second window and to condition differently the sound sequence transmitted to at least one audio exciter mounted on the first window and the sound sequence transmitted to at least one audio exciter mounted on the second window.

Description of the figures

Other features, purposes and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

FIG. 1 - there FIG. 1 is a diagram representing a vehicle window equipped with an audio exciter;

FIG. 2 - there FIG. 2 is a diagram illustrating a sound sequence processing chain that can be implemented in a possible embodiment of the invention exploiting the glazing of the FIG. 1 ;

FIG. 3 - there FIG. 3 is a diagram representing a vehicle window equipped with an audio exciter and a vibro-acoustic sensor;

FIG. 4 - there FIG. 4 is a diagram illustrating a sound sequence processing chain that can be implemented in a possible embodiment of the invention exploiting the glazing of the FIG. 3 .

Across all figures, similar elements bear identical references.

Detailed description of the invention

Referring to Figures 1 and 3, a vehicle window 1 is adapted to produce acoustic emission. To achieve this, the window 1 is equipped with an audio exciter 2. The audio exciter 2 causes the window 1 to vibrate, and this vibration generates acoustic emission.

The glazing 1 may take the form of a glazed assembly comprising at least one sheet of glass. The glazed assembly may comprise a single sheet of glass or form a laminated glazing unit comprising at least two sheets of glass with an interlayer of viscoelastic material sandwiched between them. The glass sheet(s) 13 may be made of organic or mineral glass, for example, tempered glass.

The glazing assembly may be transparent or opaque. It may include an opaque coating. The opaque coating may be paint or enamel, for example, black. The glazing assembly may consist of a transparent section and an opaque section. The opaque section may surround the transparent section. The glazing assembly may be tinted throughout its thickness, over all or part of its surface.

By using laminated glazing with a layer of viscoelastic material sandwiched 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.

The viscoelastic interlayer may comprise one or more layers of a viscoelastic polymer such as polyvinyl butyral (PVB) or an ethylene-vinyl acetate (EVA) copolymer. The interlayer is preferably made of acoustic PVB (such as single-layer or triple-layer acoustic PVB). Acoustic PVB may consist of three layers: two outer layers of standard PVB and an inner layer of PVB with a higher plasticizer content than standard PVB, making the inner layer less rigid than the outer layers. The use of acoustic PVB in laminated glass improves low-frequency reproduction and reduces vibration issues compared to standard PVB.

Glazing 1 is a vehicle glazing element. Specifically, glazing 1 can be selected from a windshield, side window, door window, rear window, or roof window. Glazing 1 can be rectangular or trapezoidal in shape. Glazing 1 can have straight or curved edges.

The glazing 1 may include a single audio exciter or several audio exciters. When several audio exciters are used, they can be used to produce acoustic emission in different frequency ranges. These different frequency ranges may correspond to the frequency ranges of speakers commonly used in vehicles: subwoofer speakers with an emission frequency typically between 20 Hz and 200 Hz, door speakers with a frequency typically between 100 Hz and 300 Hz, and tweeters with a frequency typically between 300 Hz and 16 kHz.

The audio exciter(s) 2 can be piezoelectric audio exciters, electrodynamic audio exciters (or inertial exciters), electrostatic audio exciters or magnetostrictive audio exciters.

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.

This process includes 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.

The data representing a vehicle's operating state can be data from measurements taken by sensors or data provided by the vehicle's central computer. This data can include either or both types of data representing vehicle speed, vehicle acceleration, vehicle temperature (particularly window temperature), or the operation of a vehicle component (such as the air conditioning or ventilation system). Data representing vehicle acceleration can be obtained via the vehicle's engine tachometer or through information related to the application of the vehicle's brakes. The data representing a vehicle's operating state can also be obtained through an audio recording inside the vehicle's passenger compartment.

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

The method also includes conditioning the sound sequence 5 by controller 3 through the application of a calibrated processing based on data 4 representing the vehicle's operating state. The method according to the invention thus achieves dynamic (or adaptive) conditioning of the sound sequence, adapted to the vehicle's operating state. The conditioning of the sound sequence typically involves shaping the sound sequence through filtering and/or amplification.

In one possible implementation, the processing applied to the sound sequence can also be calibrated according to the typology of the sound sequence. For example, for a sound sequence representative of a telephone call, the processing could be amplification within a mid-frequency range, for example, between 300 Hz and 5 kHz. Thus, the energy required for amplification is limited to a frequency range useful for increasing the intelligibility of a telephone conversation. Conversely, for a sound sequence representative of music played in the vehicle's interior, the processing could be amplification of the signal across all frequencies of the sound sequence.

The process then includes the transmission, by the controller, of the conditioned sound sequence to the audio exciter 2, for example via an amplifier 6.

A first example of dynamic sound sequence conditioning involves conditioning that depends on the vehicle's speed. For example, the shaping of the sound sequence through filtering and amplification differs according to the vehicle's speed. This shaping can be defined by a cutoff frequency of a low-pass filter and a gain, associated with a range of speeds. As an example, controller 3 performs the dynamic conditioning illustrated in the table below. Rolling speed Gain Cutoff frequency <50 km/h -6dB 500 Hz 50-80 km/h unitary 500 Hz 80-100 km/h +3dB 20 kHz >100 km/h +6dB 20 kHz

In particular, at low speeds, both the gain and the cutoff frequency are low. This helps limit acoustic emissions outside the vehicle in the mid to high frequency bands, whereas such emissions could pose privacy problems when the glazing is used to relay a sound source related to the human voice, such as a telephone call.

Another example of dynamic conditioning takes temperature into account. Indeed, the lower the temperature, the more rigid the laminated glass becomes due to the presence of the viscoelastic interlayer. The rigidity of the laminated glass causes a variation in sound emission. Dynamic conditioning of the sound sequence then makes it possible to correct this variation and thus free the sound emission from the effects of temperature variations.

With reference to Figures 3 and 4, the method may further include the reception, by the controller 3, of a vibro-acoustic measurement taken by a sensor 7 mounted on the glazing 1 on its inner surface facing the passenger compartment or on its outer surface. This measurement may be converted to analog-to-digital 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.

The method according to the invention allows for dynamic conditioning of sound reproduction, enabling control of sound emissions both inside and outside the vehicle. In particular, the invention ensures better protection of personal data. Furthermore, it improves the quality of sound emissions inside the passenger compartment, for example, by amplifying low frequencies to mask existing frequencies of background interior noise (for example, related to the operation of air conditioning or ventilation), by providing sound emissions independent of temperature variations, by taking into account the typology of the sound sequence, or by considering the vehicle's speed or acceleration.

The invention is not limited to the method as previously described but also extends to the controller 3 configured to implement such a method and to a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to implement such a method.

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

In one possible implementation, this system includes several audio exciters mounted on the first pane of glass, with the controller configured to condition the sound sequence transmitted to each audio exciter differently. For example, as mentioned earlier, the audio exciters can be used to produce acoustic emission across different frequency ranges, such as the frequency ranges of speakers typically used in vehicles.

In another possible embodiment, this system further includes a second vehicle window and at least one audio exciter mounted on the second window. The controller is further configured to drive at least one audio exciter mounted on the second window and to condition the sound sequence transmitted to at least one audio exciter mounted on the first window differently from the sound sequence transmitted to at least one audio exciter mounted on the second window. This system takes the form of several loudspeakers formed by different windows (e.g., roof window and door window), with sound sequence conditioning specific to each loudspeaker.

Claims (11)

Method of controlling an audio exciter (2) mounted on a vehicle window (1) to cause it to 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 a vehicle operating state;
- conditioning of the sound sequence by applying a calibrated processing based on data representative of a vehicle's operating state;
- transmission of the conditioned sound sequence to the audio exciter. A method according to claim 1, wherein the data representing a vehicle operating state are data representing a vehicle rolling speed or acceleration. A method according to any one of claims 1 and 2, wherein the processing is further calibrated according to a typology of the sound sequence. A method according to any one of claims 1 to 3, wherein the treatment is further calibrated according to a temperature. A method according to any one of claims 1 to 4, further comprising receiving a vibro-acoustic measurement made by a sensor (7) mounted on the glazing and wherein the treatment is further calibrated according to the vibro-acoustic measurement. A method according to any one of claims 1 to 5, wherein the conditioning of the sound sequence is a shaping by filtering and/or amplification. Controller (3) for controlling an audio exciter, configured to implement the steps of the process according to any one of claims 1 to 6. Product computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to any one of claims 1 to 6. Sound emission system comprising:
- a first glazing (1) of a vehicle;
- at least one audio exciter (2) mounted on the first pane of glass;
- a controller (3) for controlling at least one audio exciter, according to claim 7. Sound emission system according to claim 9, comprising several audio exciters mounted on the first glazing and in which the controller is configured to condition differently the sound sequence transmitted to each of the audio exciters. Sound emission system according to claim 9, further comprising a second vehicle window and at least one audio exciter mounted on the second window and wherein the controller is further configured to drive at least one audio exciter mounted on the second window and to condition differently the sound sequence transmitted to at least one audio exciter mounted on the first window and the sound sequence transmitted to at least one audio exciter mounted on the second window.