FR3137810A1 - Control of a sound environment in a vehicle - Google Patents

Abstract

The present invention relates to a method for controlling a sound environment of a vehicle (2), said method comprising: obtaining an initial sound signal representative of a virtual sound source (SC2) associated with the vehicle, the virtual sound source (SC2) being characterized by a spatial characteristic of apparent width representative of a space occupied by the virtual sound source (SC2) in space; converting the initial sound signal into a spatialized sound signal by processing causing at least an increase in the spatial characteristic of apparent width of the virtual sound source (SC2); and transmission of the spatialized sound signal to an acoustic restitution system (6) of the vehicle (2) to reproduce the spatialized sound signal in a passenger compartment of the vehicle (2). Figure for abstract: Figure 1

Description

Control of a sound environment in a vehicle

The present invention relates to devices and methods for generating a sound signal representative of a virtual sound source in the passenger compartment of a vehicle, in particular a motor vehicle. The invention aims in particular to restore a virtual sound source representative of the dynamics of a vehicle.

Technology background

The use of virtual sound sources, in other words synthetic sounds, is increasingly common in the automotive sector, whether outside the vehicle to alert of the presence of an electric vehicle (AVAS systems for " Acoustic Vehicle Alert System") or inside the passenger compartment to diversify the sources of information for the driver or passengers (alert sounds, notifications, etc.).

The omnipresence of synthetic sounds in motor vehicles can be explained in particular by the electrification and autonomy of vehicles. Also, it is essential, particularly for the sustainability of these solutions, that virtual sound sources are well integrated and accepted by users.

In particular, in the case of electric vehicles, it has been proposed to integrate a virtual sound source inside the passenger compartment to restore the dynamics of the vehicle, information which is no longer present due to the absence of engine sound. Indeed, the increasingly widespread use of vehicles with silent motor(s) (for example electric(s)) leads to a profound upheaval in the acoustic field both for the passengers of these vehicles and for the people located inside. exterior of the latter. This upheaval results in a loss of useful information linked to the dynamics of the vehicle and resulting from the absence of engine sound. It is in fact well known that the noise of a vehicle's engine helps to evaluate its current speed and its current acceleration, and/or the driver's intention.

To try to remedy the aforementioned drawback, it has been proposed to equip a vehicle with a device for generating sound signals (also called a “sonification” device), responsible for recreating a sound that can replace the noise of the engine. thermal and intended to provide information on its dynamics, and possibly contribute to its brand image. This technique is commonly referred to as sonification of vehicle dynamics.

The sonification of vehicle dynamics makes it possible to generate information in the form of acoustic signals to inform on the dynamics of a vehicle, in particular the engine dynamics, in order to help the driver and passengers to better perceive the behavior of the vehicle and thus increase in particular the comfort and driving quality.

Virtual sound sources make it possible in particular to relieve the visual modality of the attentional load required by the various visual indicators present in a vehicle, by transferring it to the auditory modality. This allows for increased safety and comfort, particularly for the driver of the vehicle.

The sounds likely to be produced by virtual sound sources in the passenger compartment of a vehicle are not limited to vehicle dynamics, in particular engine dynamics, but can also correspond to various virtual sound sources carrying information for the driver, such as for example switching on a turn signal. The virtual sound is not produced by the indicator itself (the physical object represented by the virtual sound) but by the virtual sound source to effectively warn the driver.

Current systems for reproducing virtual sounds in vehicle cabins, whether for sonification of vehicle dynamics or others, are however not satisfactory. In particular, they do not make it possible to effectively and naturally reproduce sounds to drivers and passengers of a vehicle, in particular a motor vehicle. Virtual sounds tend to disrupt or annoy users, thus limiting the benefits of such systems.

Summary of the present invention

One of the objects of the present invention is to solve at least one of the problems or deficiencies of the technological background described above.

Another object of the present invention is to effectively control the sound environment of a vehicle, for example of the automobile type or equivalent.

Another object of the present invention is to improve the integration of a virtual sound source into the sound environment of a vehicle, for example to provide information on vehicle dynamics or engine dynamics.

According to a first aspect, the present invention relates to a method for controlling the sound environment of a vehicle, said method comprising:
- obtaining an initial sound signal representative of a virtual sound source associated with the vehicle, said virtual sound source being characterized by a spatial characteristic of apparent width representative of a space occupied by the virtual sound source in space;
- conversion of the initial sound signal into a spatialized sound signal by processing causing at least an increase in said spatial characteristic of apparent width of the virtual sound source; And
- transmission of the spatialized sound signal to an acoustic restitution system of the vehicle to restore the spatialized sound signal in a passenger compartment of the vehicle.

This control method is for example implemented by a sound environment control device (also called control device).

The present invention advantageously makes it possible to better integrate a virtual sound source into the sound environment of a vehicle, and therefore to improve the comfort of the driver and passengers. Users are in particular able to better perceive the behavior or operation of the vehicle from the virtual sound source, which makes it possible to limit possible disturbances among users and to improve driving comfort and road safety. Furthermore, if the added virtual sources are intrinsically better accepted by users, freedom in the choice of their sound characteristics is more important. The invention makes it possible to improve the acceptance of virtual sound sources by playing on their spatial characteristics, in particular on their apparent width, therefore leaving great freedom in the choice of the synthesized sounds used.

According to a particular embodiment, the method further comprises:
- determination of an application according to which the virtual sound source must be restored; And
- determination, from said application, of a set value of the spatial characteristic of apparent width,
in which the processing during said conversion is adapted to increase said spatial characteristic of apparent width of the virtual sound source according to the set value.

According to a particular embodiment, the sound emitted by the virtual sound source simulates at least one hardware component embedded in the vehicle.

According to a particular embodiment, the sound emitted by the virtual sound source is representative of vehicle dynamics.

According to a particular embodiment, the treatment comprises:
- obtaining sound signals decorrelated from each other, by applying decorrelating processing to the initial sound signal;
the decorrelated sound signals, collectively forming the spatialized sound signal, being transmitted to the acoustic restitution system (6) of the vehicle to be reproduced respectively by separate speakers (8) of said acoustic reproduction system.

According to a particular embodiment, the decorrelating processing comprises:
- application of a plurality of random phase all-pass filters to the initial sound signal to obtain the sound signals decorrelated from each other.

According to a particular embodiment, the method comprises:
- obtaining filtered sound signals by filtering the initial sound signal by means of a plurality of complementary filters so that the sum of said filtered sound signals is equal to the initial sound signal; And
the filtered sound signals being transmitted to the acoustic restitution system to be reproduced respectively by separate speakers of said acoustic reproduction system at distinct virtual positions.

According to a second aspect, the present invention relates to a sound environment control device (also called control device), the device comprising a memory associated with a processor configured for implementing the steps of the control method according to the first aspect of the present invention.

Note that the different embodiments mentioned above in relation to the control method according to the first aspect of the invention as well as the associated advantages apply analogously to the control device according to the second aspect of the invention .

According to a third aspect, the present invention relates to a system comprising a control device according to the second aspect of the present invention as well as an acoustic restitution system comprising loudspeakers for restoring the spatialized sound signal transmitted by said control device.

According to a fourth aspect, the present invention relates to a vehicle, for example of the automobile type or of the land motor vehicle type, comprising a control device according to the second aspect of the present invention, or comprising a control system according to the third aspect of the present invention. This vehicle can for example be an autonomous or semi-autonomous vehicle. This vehicle is for example a motor vehicle driven by electrical energy.

According to a fifth aspect, the present invention relates to a computer program which comprises instructions adapted for the execution of the steps of the control method according to the first aspect of the present invention, in particular when the computer program is executed by at minus a processor. In other words, the different stages of the control process are determined by computer program instructions. This computer program is configured to be implemented in a control device of the second aspect of the invention, or more generally in a computer.

Such a computer program can use any programming language, and be in the form of a source code, an object code, or an intermediate code between a source code and an object code, such as in partially compiled form, or in any other desirable form.

According to a sixth aspect, the present invention relates to a recording medium (or information medium), readable by the control device according to the second aspect or more generally by a computer (or a processor), on which a program is recorded computer comprising instructions for executing the steps of the control method according to the first aspect of the present invention.

On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a ROM memory of the microelectronic circuit type, or even a magnetic recording means or a hard disk.

On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or terrestrial radio or by self-directed laser beam or by other ways. The computer program according to the present invention can in particular be downloaded onto an Internet type network.

Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in executing the method in question.

Brief description of the figures

Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting examples of embodiment of the present invention below, with reference to the appended Figures 1 to 4, in which:

illustrates a passenger compartment of a vehicle carrying a control device and a control system, according to a particular and non-limiting embodiment of the present invention;

schematically illustrates the device for controlling the , according to a particular and non-limiting embodiment of the present invention;

schematically illustrates a control device configured to control the sound environment of a vehicle as shown in Figures 1 and 2, according to a particular and non-limiting embodiment of the present invention; And

illustrates a diagram of different stages of a process for controlling the sound environment of a vehicle as shown in Figures 1-2, according to a particular and non-limiting embodiment of the present invention.

Description of the implementation examples

Until now, developments and choices relating to the design of acoustic sources to achieve sonification of vehicle dynamics have focused on the quality of the transmission of the desired information but little on the way in which these sounds were integrated. in the existing soundscape. Solutions for integrating these sounds are currently limited to the use of the vehicle's audio architecture. Outside, a single speaker from an AVAS system may possibly be present under the hood of a motor vehicle to broadcast sounds to surrounding people. In the passenger compartment of a motor vehicle, sounds may possibly be broadcast through the speakers available in the vehicle.

The applicant noted that current solutions for sonifying vehicle dynamics encounter significant rejection among users due to a lack of belonging of the synthetic sounds (or virtual sound sources) in the vehicle cabin. The main drawback of these synthetic sounds, particularly vehicle dynamics sonification sounds, is their lack of integration into the general sound environment of the vehicle. These synthetic sounds fulfill their role but are reported by users as not belonging to the vehicle, as not being “natural”. Current solutions therefore face a problem of lack of unity, of mixture, of coherence between the real sounds audible in the vehicle (or sound environment) and the added synthetic sounds. In other words, the virtual sound sources generated by current solutions are not consistent with the other sound sources in the passenger compartment, namely with the real sound sources of the vehicle. These effects of non-coherence or non-belonging lead to a rejection of current solutions by users.

The present invention therefore aims to resolve the problems and deficiencies described above by reducing this effect of non-membership (or non-coherence), in order to improve the general sound environment of a vehicle and offer more freedom in choice. synthesized sounds used.

By studying the way in which “natural” sound sources, that is to say produced by material components of the vehicle (i.e. engine noise, rolling noise, etc.), diffuse acoustic energy into the passenger compartment, and how this energy is perceived by users, it was determined that these sounds are naturally diffused relatively widely in the passenger compartment. This is explained by the very structure of a vehicle, which has the effect that natural sounds do not come from localized and identifiable areas of the passenger compartment but are on the contrary perceived as being broad and not specific. The present invention relies on this phenomenon of acoustic diffusion to improve the integration of virtual sound sources in the passenger compartment of a vehicle, in order to improve the coherence of synthetic sounds with the rest of the vehicle's sound environment. .

A device for controlling the sound environment (also called a control device) of a vehicle, as well as a method for controlling such a device, will now be described in what follows with reference jointly to Figures 1-4 . Unless otherwise indicated, elements common or similar to several figures bear the same reference signs and have identical or similar characteristics, so that these common elements are generally not described again for the sake of simplicity.

The terms “first(s)” (or first(s)), “second(s)”, etc.) are used in this document by arbitrary convention to help identify and distinguish different elements (such as operations, threshold values, etc.) implemented in the embodiments described below.

By “virtual sound source”, we mean in this document any synthetic sound associated with (or simulating the) vehicle, this sound being produced by one or more speakers (or equivalent) on board the vehicle. In other words, a virtual sound source carries acoustic information relating to the vehicle, for example relating to one or more material components (or physical object) of the vehicle considered or relating to the environment close to the vehicle. The nature of a virtual sound source may vary depending on the case, the present invention not being limited to a particular type of virtual sound source, or to a type of hardware component represented by (or simulated by) such a virtual sound source.

For example, in an automobile passenger compartment, a virtual sound source within the invention can correspond to a sonification of vehicle dynamics, for example to a sound representative of the engine of the vehicle in question. The invention is, however, not limited to the sonification of vehicle dynamics. Alternatively, the present invention can make it possible to generate a virtual sound source representative of the sound of a turn signal to indicate for example the switching on of the turn signal (the synthetic sound is not produced by the hardware component itself, namely the flashing light, but reproduced by loudspeakers as described below).

According to another example, the present invention can make it possible to generate a virtual sound source representative of an element (obstacle or other) external to the vehicle, for example in a vicinity close to the vehicle. In this case, the element in question can be detected by a hardware component of the vehicle, namely for example a sensor.

The “dynamics of a vehicle” designates in this document at least one characteristic representative of a movement or a state of the vehicle, for example the current speed of the vehicle, the current acceleration of a vehicle, as well as possibly certain dynamic characteristics such as the current position of the vehicle's accelerator pedal, etc. Generally speaking, the sonification of the dynamics of a vehicle aims to produce a virtual sound source representative of the dynamics of said vehicle, in particular to help the driver to better perceive the behavior of the vehicle.

In known manner, any sound source is by nature characterized by spatial characteristics of said sound source, including:
- a spatial location characteristic representative of the direction of arrival of the sound produced by the sound source in relation to a reference point (a user for example);
- a spatial distance characteristic representative of the perceived distance of the sound source relative to a reference point (a user for example); And
- a spatial characteristic of apparent width – denoted L below – representative of the width that the sound source occupies (or is supposed to occupy) in space.

The present invention proposes to play more particularly on the parameter of the spatial characteristic of apparent width to improve the integration of a synthetic sound in the passenger compartment of a vehicle. In particular, the invention provides for converting an initial sound signal, representative of a virtual sound source, into a spatialized sound signal by increasing the spatial characteristic of apparent width of the virtual sound source.

According to a particular and non-limiting example of embodiment, a method is proposed for controlling the sound environment of a vehicle, said method comprising:
- obtaining an initial sound signal representative of a virtual sound source associated with at least one hardware component of the vehicle, said virtual sound source being characterized by a spatial characteristic of apparent width representative of a space that occupies (or is supposed to occupy) the virtual sound source in space;
- conversion of the initial sound signal into a spatialized sound signal by processing causing at least an increase in said spatial characteristic of apparent width of the virtual sound source; And
- transmission of the spatialized sound signal to an acoustic restitution system of the vehicle to restore the spatialized sound signal in a passenger compartment of the vehicle

The present invention applies to controlling the sound environment of a vehicle, such as an automobile or other type vehicle, or more generally a motorized land vehicle type vehicle. The invention aims in particular, but not exclusively, at controlling an autonomous or semi-autonomous vehicle.

The invention applies in particular, but not exclusively, to the generation of a virtual sound source representative of the dynamics of a vehicle, for example the engine dynamics of the vehicle. Alternatively, the virtual sound source is representative of one or more hardware components of a vehicle.

Thanks to the invention, it is possible to reproduce in a relatively broad manner a virtual sound source representative of at least one hardware component of a vehicle. The invention makes it possible to better integrate a virtual sound source into the sound environment of a vehicle, and therefore to improve the comfort of the driver and passengers. Users are in particular able to better perceive the behavior or operation of the vehicle from the virtual sound source, which makes it possible to limit possible disturbances among users and to improve driving comfort and road safety.

Furthermore, if the added virtual sources are intrinsically better accepted by users, freedom in the choice of their sound characteristics is more important. The invention makes it possible to improve the acceptance of virtual sound sources by playing on their spatial characteristics, in particular on their apparent width, therefore leaving great freedom in the choice of the synthesized sounds used.

The invention makes it possible in particular to effectively reproduce in the form of a virtual sound source the dynamics of a vehicle, for example the engine dynamics of said vehicle, other examples being however possible.

There schematically illustrates a passenger compartment of a vehicle 2 according to a particular embodiment. The vehicle 2 is for example of the automobile type although other types of vehicle are possible. Alternatively, the vehicle 2 is a coach, a bus, a truck, a utility vehicle, or more generally a vehicle of the motorized land vehicle type.

According to a particular example, the vehicle 2 is a vehicle with an electric motor.

According to a particular example, the vehicle 2 is an autonomous or semi-autonomous vehicle. More particularly, the vehicle 2 can circulate according to a level of autonomy equal to 0 or according to a level of autonomy ranging from 1 to 5 for example, according to the scale defined by the American federal agency which has established 5 levels of autonomy. autonomy ranging from 1 to 5. Level 0 corresponds to a vehicle having no autonomy, the driving of which is under the total supervision of the driver; level 1 corresponding to a vehicle with a minimum level of autonomy, whose driving is under the supervision of the driver with minimal assistance from an ADAS system (from the English “Advanced Driver-Assistance System” or in French “System advanced driving assistance"); and level 5 corresponding to a completely autonomous vehicle.

The 5 levels of autonomy in the classification of the federal agency responsible for road safety are:

- level 0: no automation, the vehicle driver has full control over the main functions of the vehicle (engine, accelerator, steering, brakes);

- level 1: driver assistance, automation is active for certain vehicle functions, the driver maintaining overall control over vehicle driving; cruise control is part of this level, like other aids such as ABS (anti-lock braking system) or ESP (programmed electro-stabilizer);

- level 2: automation of combined functions, the control of at least two main functions is combined in the automation to replace the driver in certain situations; for example, adaptive cruise control combined with lane centering allows a vehicle to be classified level 2, as does automatic parking assistance;

- level 3: limited autonomous driving, the driver can cede complete control of the vehicle to the automated system which will then be in charge of critical safety functions; however, autonomous driving can only take place in certain specific environmental and traffic conditions (only on motorways for example);

- level 4: complete autonomous driving under conditions, the vehicle is designed to ensure all critical safety functions alone over a complete journey; the driver provides a destination or navigation instructions but is not required to make himself available to regain control of the vehicle;

- level 5: completely autonomous driving without driver assistance in all circumstances.

Vehicle 2 can be configured according to any of the autonomy levels mentioned above. According to a particular embodiment, the vehicle 2 is configured in a semi-autonomous or autonomous mode, that is to say with a level of autonomy greater than or equal to 2 according to the classification above.

As illustrated in , the vehicle 2 comprises a device 4 for controlling the sound environment (also called control device 4) and an acoustic restitution system 6 collectively forming a control system 10. The device 4 for controlling the sound environment and the system 6 are configured to cooperate in order to reproduce (or restore) a virtual sound source SC2 in the passenger compartment of the vehicle 2, this virtual sound source SC2 being associated with (or representative of) at least one hardware component SC1 of the vehicle 2.

In the example considered here, the control device 4 and the acoustic restitution system 6 are on board the vehicle 2, although other examples of implementation are possible. Alternatively, the control device 4 is for example implemented outside (or independently) of the vehicle 2, said control device 4 being able to remotely control the acoustic restitution system 6.

More precisely, the control device 4 is configured to control the sound environment of the vehicle 2. To do this, the control device 4 controls the acoustic restitution system 6 so that the latter reproduces acoustically, in the passenger compartment of the vehicle 2 , a virtual sound source SC2 representative of at least one hardware component (or physical object) SC1 of the vehicle 2. The hardware component(s) SC1 simulated at the acoustic level by the control device 4, and more generally by the control system 10 , can be of various natures. For example, the virtual sound source SC2 thus reproduced represents a dynamic of the vehicle 2, for example an engine dynamic of the vehicle 2. It is then possible to sonify a vehicle dynamic as already indicated. Alternatively, the virtual sound source SC2 simulates the sound produced by another hardware component SC1, such as a turn signal for example.

The control device 4 can for example take the form of (or include a) calculator, or a combination of calculators. An example of implementation of the control device 4 is described later.

The acoustic restitution system 6 is capable of acoustically restoring the virtual sound source SC2 from sound signals transmitted for this purpose by the control device 4, as described in more detail later. For this purpose, the acoustic reproduction system 6 comprises a plurality of speakers 8 on board the vehicle 2 so as to be able to reproduce the virtual sound source SC2 in the passenger compartment of the vehicle 2. In other words, the speakers 8 are thus configured to restore synthesis sounds 9 collectively forming the virtual sound source SC2.

The configuration of the speaker(s) 8 in particular in terms of number, arrangement, positioning, etc. can be adapted depending on the case. These speakers 8 together form a network of speakers 8 controllable by the control device 4 to reproduce the virtual sound source SC2 in the passenger compartment.

Note that the loudspeaker network 8 must comprise at least two loudspeakers 8. The spatial characteristic of apparent width that it is possible to achieve as a maximum depends on the arrangement of the loudspeakers 8: the maximum width is less than or equal to the spacing between the two speakers 8 farthest from the network.

According to a particular example, the virtual sound source SC2 is implemented as part of an application executed by the control device 4. In other words, the control process implemented by the control device 4 as described below , may be part of or be associated with a function executed by the control device 4. The nature of this application may vary depending on the case. This could be, for example, an application for reproducing vehicle dynamics or engine dynamics.

According to a particular example illustrated in , the control device 4 comprises a processor 20 and a non-volatile memory 22. The memory 22 is a rewritable non-volatile memory or a read-only memory (ROM), this memory constituting a recording medium (or information medium) conforming to to a particular embodiment, readable by the control device 4, and on which a computer program PG1 conforming to a particular embodiment is recorded. This computer program PG1 includes instructions for executing the steps of a control process (or method) according to a particular embodiment. The steps of this control process (or method) are described later with reference to the figures.

As indicated below, the control device 4 can obtain an initial sound signal SG1, the latter being able to be stored in the volatile memory 22 or in any other memory (volatile or non-volatile) of the control device 4.

The control device 4, and more generally the control system 10, are configured to implement a control process when the computer program PG1 is executed by the processor 20. This process is now described jointly in Figures 1 and 2 according to particular embodiments.

According to a particular example, the processor 20 controlled by the computer program PG1 implements modules MD2, MD4 and MD6 (or at least any one of these modules) as described below.

In a first operation, the control device 4 obtains an initial sound signal (or original sound signal) SG1 representative of a virtual sound source SC2 associated with at least one hardware component SC1 of the vehicle 2, this virtual sound source SC2 being characterized by a spatial characteristic of apparent width L1 representative of a space occupied by the virtual sound source SC2 in space (or at least a space that this source is supposed to occupy in the case of acoustic restitution). In other words, the virtual sound source SC2 acoustically represents one or more hardware components SC1 of the vehicle 2, such as an engine or a turn signal of the vehicle 2. The virtual sound source SC2 defines a synthetic sound which is not produced by the material component(s) SC1 themselves, but which can be reproduced by the acoustic reproduction system 6 in the passenger compartment of the vehicle 2 to integrate into the sound environment of the vehicle 2.

The manner in which the control device 4 obtains the initial sound signal SG1, as well as the form and content of this signal, can be adapted as appropriate. According to a particular example, the control device 4 comprises a synthesis module (or synthesizer) MD2 configured to synthesize the initial sound signal SG1. This initial sound signal SG1 is therefore a synthesis signal generated by the synthesizer MD2, for example according to synthesis parameters which can be adapted depending on the case.

According to a variant, the control device 4 recovers the initial sound signal SG1 previously stored in the memory 22. According to a variant, the control device 4 determines the initial sound signal SG1 from sensor data received from at at least one sensor embedded in the vehicle 2. These sensor data are for example representative of the state of at least one hardware component SC1 of the vehicle 2 over time. According to a variant, the control device 4 receives the initial sound signal SG1 from the outside, for example from a computer of the vehicle 2 or from a terminal external to the vehicle 2.

In a second operation, the control device 4 converts the initial sound signal SG1 into a spatialized sound signal SG2 by processing causing at least an increase in the spatial characteristic of apparent width L1 of the virtual sound source SC2. It is assumed, for example, that the spatialized sound signal SG2 has a spatial characteristic of apparent width L2 greater than the spatial characteristic of apparent width L1 of the initial sound signal SG1.

Examples of implementations of such processing are described in more detail later. This processing is for example carried out by a processing module MD4 implemented by the processor 20 in accordance with the computer program PG1.

According to a particular example, the processing thus carried out by the control device 4 is configured to increase the spatial characteristic of apparent width L1 of the virtual sound source SC2 according to a predefined setpoint value. From this setpoint value, the control device 4 determines to what level the spatial characteristic of apparent width L1 must be increased. This setpoint value is for example a threshold value to which the apparent width L2 must at least be equal at the end of the aforementioned processing.

There is no absolute ideal value for the spatial characteristic of apparent width, the appropriate setpoint value depending in particular on the structure of the vehicle 2 considered or even on the application envisaged.

According to a particular example, during the second operation, the control device 4 determines an application according to which the virtual sound source SC2 must be restored and determines, from said application, the set value according to which the characteristic must be increased space of apparent width L1. Thus, the processing carried out during the second operation can be adapted to increase the spatial characteristic of apparent width L1 of the virtual sound source SC2 according to the set value thus determined.

In a third operation, the control device 4 transmits the spatialized sound signal SG2 to the acoustic restitution system 6 of the vehicle 2 to restore the spatialized sound signal SG2 in the passenger compartment of the vehicle 2. For this purpose, the processor 20 controlled by the computer program PG1 for example implements a transmission module MD6 configured to transmit the spatialized sound signal SG2 to the acoustic restitution system 6 in any format and in any appropriate manner.

According to a particular example, the spatialized sound signal SG2 comprises a plurality of data packets defining sounds to be reproduced by respective speakers 8 of the acoustic restitution system 6 (these data packets collectively forming the spatialized sound signal SG2). These data packets can then be processed in any appropriate way by the acoustic restitution system 6 to acoustically restore the virtual sound source SC2.

On reception of the spatialized sound signal SG2, the speakers 8 reproduce in acoustic form the spatialized sound signal SG2 representative of the virtual sound source.

The spatialized sound signal SG2 is designed to occupy by nature a larger space in the passenger compartment than the initial sound signal SG1 due to the increase in the spatial characteristic of apparent width L produced during the processing of the second operation. In other words, because L2 > L1, the spatialized sound signal SG2 gives the impression for a user of coming from a virtual sound source which is larger (occupies more space) than if the initial sound signal SG1 were reproduced instead of SG2 by the acoustic restitution system 6.

Examples of implementation of the processing carried out during the second operation to increase the spatial characteristic of apparent width of the virtual sound source SC2 will now be described with reference to Figures 1 and 2.

According to a first example of implementation, during the second aforementioned operation, the control device 4 obtains sound signals decorrelated from each other, by applying a decorrelating processing (or decorrelating filter) to the initial sound signal SG1. This decorrelating processing can be adapted depending on the case insofar as it makes it possible to decorrelate the initial sound signal SG1 so as to obtain sound signals decorrelated from each other. For example, during the second aforementioned operation, the control device 4 obtains decorrelated sound signals by application, to the initial sound signal SG1, of a plurality of random phase all-pass filters. The random nature of the phase of the filters guarantees that the signals thus obtained are uncorrelated from each other. Other decorrelating treatments are however possible. For example, we can use any filters provided that they are decorrelated from each other to guarantee that the signals obtained are decorrelated from each other. These decorrelated sound signals collectively form the spatialized sound signal SG2. In other words, it is thus possible to form the spatialized sound signal SG2 comprising multiple channels composed respectively of the decorrelated signals previously obtained. The decorrelated signals forming the spatialized sound signal SG2 are then transmitted, during the third aforementioned operation, by the control device 4 to the acoustic restitution system 6 of the vehicle 2 to be reproduced respectively by the speakers 8, distinct from each other. of the others, of the acoustic restitution system 6. In this way, each decorrelated signal is acoustically restored by a dedicated speaker 8 of the acoustic restitution system 6. Thus, the multiple decorrelated signals constituting the respective channels of the spatialized sound signal SG2 are combine in the air to form the virtual source SC2 with increased apparent width. In other words, the collective restitution, by the respective speakers 8, of the decorrelated sound signals makes it possible to produce the virtual sound source SC2 with a spatial characteristic of increased apparent width as previously described.

An all-pass filter, also called a phase-shift filter or phase-correcting cell, has by nature an identical gain (constant frequency response and equal to one) over the entire frequency range used, but the relative phase of the frequencies that make up the signal in output varies with frequency. The application of random phase all-pass filters makes it possible to decorrelate the sound signals which must be emitted by each loudspeaker 8 of the acoustic restitution system 6.

According to a particular example, the decorrelation of audio signals as described above can be carried out by implementing the technique described in the document entitled “The decorrelation of audio signals and its impact on spatial imagery” (Kendall, G. S., 1995, Computer Music Journal, 19(4), 71-8).

According to a particular example, during the processing of the second operation, the random phase all-pass filters applied to the initial sound signal SG1 are filters distinct from each other. In other words, the same sound signal SG1 is filtered by different all-pass filters presenting a random phase.

According to a particular example, each decorrelated sound signal obtained during the processing of the second operation is a unique decorrelated version of the initial sound signal. Thus, each combined sound signal, resulting from a combination of one of the sound signals decorrelated with the initial sound signal SG1, is transmitted during the third operation to the acoustic restitution system 6 of the vehicle 2 to be reproduced by a high -respective speaker 8 of said acoustic restitution system 6. In other words, for each speaker 8 of the acoustic restitution system 6, a single decorrelated signal is combined with the initial sound signal SG1 then broadcast by a dedicated speaker 8.

According to a particular example, the random phase all-pass filters are configured so that the ratio between each decorrelated sound signal and the initial sound signal SG1 is at least equal to a threshold value denoted V1. The greater the decorrelated signal to original signal ratio, the greater the apparent width of the virtual sound source SC2. The threshold value V1 can be adapted by those skilled in the art on a case-by-case basis, depending in particular on the structure of the vehicle 2.

The first example of implementation described above is advantageous in that its effectiveness in terms of widening the virtual sound source is independent of the sound content of said virtual sound source, in terms of both the type of sound emitted and the intensity of the sound emitted. Thus, this technique makes it possible to coherently integrate the virtual sound source into the sound environment of the vehicle while guaranteeing great flexibility in the content of the synthetic sounds used. This allows increased personalization of virtual sound sources depending on brands, vehicles, target customers, etc. In addition, the implementation of this first implementation example does not require modification of existing hardware solutions (already integrated into vehicles), which makes it possible to minimize implementation costs.

According to a second example of implementation, during the second aforementioned operation, the control device 4 obtains sound signals filtered by filtering the initial sound signal SG1 by means of a plurality of complementary filters so that the sum of said sound signals filtered is equal to the initial sound signal SG1. Each filtered sound signal corresponds to a version of the initial sound signal SG1, filtered by one of the complementary filters. To restore the virtual sound source SC2 in the passenger compartment of vehicle 2, it is necessary that the filtered sound signals be spatialized at distinct virtual positions so as to be perceived at different locations in space. Also, the control device 4 transmits the filtered signals to the acoustic restitution system 6 so that they are reproduced by the speakers 8 to form secondary virtual sources at different positions in space. The combination of these virtual sources in the air thus forms the SC2 virtual sound source perceived by users. The fact that these secondary virtual sources are perceived at different positions in space for the users makes it possible to collectively form the virtual sound source SC2 with a spatial characteristic of increased apparent width.

Each filtered sound signal must in fact be distinctly localized in space using an appropriate spatialization technique, such as for example by amplitude panning (also known as “amplitude panning” in English). This technique consists of adjusting the acoustic intensity (sound intensity) reproduced by each speaker 8 to respectively adjust the virtual positions (that is to say the positions perceived by a user) of the filtered sound signals. The collective reproduction, by the speakers 8, of the filtered sound signals makes it possible to produce the virtual sound source SC2 with a spatial characteristic of increased apparent width as previously described.

The filtering of the initial sound signal SG1 during the processing of the second operation can thus be carried out by a bank of complementary filters, that is to say by filters whose sum of the filtered signals is equal to the original signal SG1 . The filtered signals are then spatially separated by amplitude panning. The more the signals thus filtered are separated from each other, the greater the apparent width L2 of the virtual sound source SG2. The separation is carried out so that the spacing is at least equal to a threshold value.

Spatialization techniques other than that known as amplitude panning can however be used in alternative embodiments. It is possible, for example, to implement a delay panning technique (or “delay panning”) which makes it possible to play on time shifts (or delays) in the acoustic reproduction by the speakers 8. Thus, the speakers 8 can be configured to acoustically restore the same filtered signal at times offset in time.

There schematically illustrates the control device 4 configured to control an acoustic restitution system, as described above with reference to Figures 1-2, according to a particular and non-limiting embodiment of the present invention. The control device 4 corresponds for example to a device on board the vehicle 2, for example a computer.

The control device 4 is for example configured for the implementation of the operations of the control process as previously described with regard to Figures 1-2 and/or the steps of the method described below with regard to the . Examples of such a control device 4 include, without being limited to, on-board electronic equipment such as an on-board computer of a vehicle, an electronic computer such as an ECU (“Electronic Control Unit”), a smartphone, a tablet, a laptop. The elements of the control device 4, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and/or into discrete components. The control device 4 can be produced in the form of electronic circuits or software (or computer) modules or even a combination of electronic circuits and software modules.

The control device 4 comprises one (or more) processor(s) 40 configured to execute instructions for carrying out the steps of the method (or the control process) and/or for executing the instructions of the software(s) embedded in the control device 4. The processor 40 may include integrated memory, an input/output interface, and various circuits known to those skilled in the art. The control device 4 further comprises at least one memory 41 corresponding for example to a volatile and/or non-volatile memory and/or comprises a memory storage device which may comprise volatile and/or non-volatile memory, such as EEPROM , ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

The computer code of the embedded software(s) comprising the instructions to be loaded and executed by the processor 40 is for example stored on the memory 41. The memory 41 can constitute an information medium according to a particular embodiment in that it comprises a computer program (for example PG1 in ) comprising instructions for carrying out the steps of the method (or control process) of the invention.

According to different particular and non-limiting examples of embodiment, the control device 4 is coupled in communication with other similar devices or systems and/or with communication devices, for example a TCU (from the English "Telematic Control Unit") or in French “Telematic Control Unit”), for example via a communications bus or through dedicated input/output ports.

According to a particular and non-limiting exemplary embodiment, the control device 4 comprises a block 42 of interface elements for communicating with external devices, for example a remote server or the "cloud", or the vehicle 2 when the device control 4 corresponds to a smartphone or a tablet for example. The interface elements of block 42 include one or more of the following interfaces:

- RF radio frequency interface, for example of the Wi-Fi® type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or of the Bluetooth® type (according to IEEE 802.15.1), in the band frequency at 2.4 GHz, or Sigfox type using UBN radio technology (from English Ultra Narrow Band, in French ultra narrow band), or LoRa in the 868 MHz frequency band, LTE (from English “ Long-Term Evolution” or in French “Long-Term Evolution”), LTE-Advanced (or in French LTE-advanced);

- USB interface (from the English “Universal Serial Bus” or “Bus Universel en Série” in French);

- HDMI interface (from the English “High Definition Multimedia Interface”, or “Interface Multimedia Haute Definition” in French).

According to another particular and non-limiting example of embodiment, the control device 4 comprises a communication interface 43 which makes it possible to establish communication with other devices (such as other computers of the on-board system or on-board sensors) via a communication channel 45. The communication interface 43 corresponds for example to a transmitter configured to transmit and receive information and/or data via the communication channel 45. The communication interface 43 corresponds for example to a wired network type CAN (from the English “Controller Area Network” or in French “Réseau de controlleres”), CAN FD (from the English “Controller Area Network Flexible Data-Rate” or in French “Network of data rate controllers”) flexible"), FlexRay (standardized by the ISO 17458 standard), Ethernet (standardized by the ISO/IEC 802-3 standard) or LIN (from the English "Local Interconnect Network", or in French "Local Interconnected Network").

The control device 4 is for example coupled to the acoustic restitution system 6 by means of the block 42 of interface elements or the communication interface 43 so that the spatialized sound signal SG2 can be transmitted to the monitoring system. acoustic restitution 6 as previously described.

According to a particular and non-limiting embodiment, the control device 4 can provide output signals to one or more external devices, such as a display screen, touch or not, one or more speakers and/or other devices (projection system) via respective output interfaces. According to one variant, one or the other of the external devices is integrated into the control device 4.

There illustrates a diagram of the different stages of a method of controlling the device 4 for controlling the sound environment of the vehicle 2 as previously described. The method is for example implemented by the control device 4, or more generally by the control system 10, these elements being able to be embarked in the vehicle 2.

In a first step 51, an initial sound signal SG1 representative of a virtual sound source SC2 associated with at least one hardware component SC1 of the vehicle 2 is obtained, this virtual sound source SC2 being characterized by a spatial characteristic of apparent width L1 representative of 'a space occupied by the virtual sound source SC2 in space.

In a second step 52, the initial sound signal SG1 is converted into a spatialized sound signal SG2 by processing causing at least an increase in the spatial characteristic of apparent width L1 of the virtual sound source SC2.

In a third step 53, the spatialized sound signal SG2 is transmitted to the acoustic restitution system 6 of the vehicle 2 to restore the spatialized sound signal SG2 in the passenger compartment of the vehicle 2.

According to alternative embodiments, the variants and examples of the operations described above in relation to Figures 1-3 apply to the stages of the process for controlling the .

A person skilled in the art will understand that the embodiments and variants described above constitute only non-limiting examples of implementation of the invention. In particular, those skilled in the art may consider any adaptation or combination of the embodiments and variants described above, in order to meet a very specific need.

The present invention is therefore not limited to the exemplary embodiments described above but extends in particular to a control method which would include secondary steps without thereby departing from the scope of the present invention. The same would apply to a control device configured for the implementation of such a process.

The present invention also relates to a vehicle, for example an automobile or more generally a vehicle with a land motor, for example with a motor driven by electrical energy, comprising the control device 4 as previously described.

Claims (10)

Method for controlling the sound environment of a vehicle (2), said method comprising:
- obtaining (51) an initial sound signal (SG1) representative of a virtual sound source (SC2) associated with the vehicle, said virtual sound source being characterized by a spatial characteristic of apparent width (L1) representative of a space that occupies the virtual sound source in space;
- conversion (52) of the initial sound signal (SG1) into a spatialized sound signal (SG2) by processing causing at least an increase in said spatial characteristic of apparent width (L1) of the virtual sound source; And
- transmission (53) of the spatialized sound signal (SG2) to an acoustic restitution system (6) of the vehicle to restore the spatialized sound signal in a passenger compartment of the vehicle. A method according to claim 1, said method further comprising:
- determination of an application according to which the virtual sound source (SC2) must be reproduced; And
- determination, from said application, of a set value of the spatial characteristic of apparent width (L1),
in which the processing during said conversion is adapted to increase said spatial characteristic of apparent width (L1) of the virtual sound source according to the set value. Method according to claim 1 or 2, in which the sound (9) emitted by the virtual sound source (SC2) simulates at least one hardware component (SC1) on board the vehicle (2). Method according to any one of the preceding claims, in which the sound (9) emitted by the virtual sound source is representative of vehicle dynamics. Method according to any one of the preceding claims, in which the treatment comprises:
- obtaining sound signals decorrelated from each other, by applying decorrelating processing to the initial sound signal;
the decorrelated sound signals, collectively forming the spatialized sound signal (SG2), being transmitted to the acoustic restitution system (6) of the vehicle to be reproduced respectively by separate speakers (8) of said acoustic reproduction system. Method according to claim 5, the decorrelating processing comprising:
- application of a plurality of random phase all-pass filters to the initial sound signal to obtain the sound signals decorrelated from each other.
Method according to any one of claims 1 to 4, in which said method comprises:
- obtaining filtered sound signals by filtering the initial sound signal (SG1) by means of a plurality of complementary filters so that the sum of said filtered sound signals is equal to the initial sound signal; And
the filtered sound signals being transmitted to the acoustic restitution system (6) to be reproduced respectively by loudspeakers (8) of said acoustic reproduction system at distinct virtual positions. Device (4) for controlling a sound environment of a vehicle (2), said device comprising a memory (41) associated with at least one processor (40) configured for implementing the steps of the method according to one any of the preceding claims. System for generating the sound environment of a vehicle comprising:
- the device (4) for controlling a sound environment according to claim 8; And
- an acoustic restitution system (6) comprising speakers (8) to reproduce the spatialized sound signal (SG2) transmitted by the control device. Vehicle (6) comprising the control device (4) according to claim 8 or the system according to claim 9.