Patent Description:
The system according to the present invention is especially suitable for use in automobiles and will be described hereinafter with reference to such an application without intending in any way to limit its possible areas of application to other types of motor vehicles having a passenger compartment designed to accommodate people, such as buses, trucks, et cetera, which may be engaged in telephone communications while being onboard of the motor vehicle.

As is well known, the development of the so-called mobile telephony and the now widely used cellular telephones makes it possible to conduct telephone communications almost anywhere and at any time.

One of the areas where this potential has been found to be useful and exploited is certainly in the field of motor vehicle transportation.

Unfortunately, at least at an early stage, the use of such devices in vehicles on the move, particularly by drivers, brought significant safety problems and forced authorities to promulgate increasingly stringent regulations aimed at preventing drivers from holding cell phones conversing on the phone while driving their vehicles.

In order to meet these regulations and still allow the potential of mobile communication to be exploited even while driving, as is well known, solutions have been developed that nowadays make it possible to make phone calls by interfacing directly with the audio system installed in vehicles. In fact, such a system operationally links with the cell phone, which no longer has to be held by the driver, and acts as a transmission bridge with the remote user at the other end of the communication.

While such solutions have certainly made a significant contribution in terms of safety, they also entail some drawbacks, particularly in terms of privacy.

In fact, a communication received by the on board system, for example of a car, is radiated not only inside the passenger compartment but unfortunately also outside it, at least up to a certain distance.

In fact, it is not uncommon for people on the street to be able to distinctly hear what is being said during an on-board telephone conversation in a nearby motor vehicle, which is clearly detrimental to privacy.

<CIT> discloses a method for providing phone calls in a vehicle which includes: providing first sound signal in which phone call sound is beam formed to be audible only to a first occupant, by controlling a first directional speaker, when phone call request for the first occupant in the vehicle is received; and providing second sound signal different from the first sound signal which is beam formed to be audible to a second occupant, by controlling a second directional speaker, while the first phone call sound is provided.

<CIT> discloses a recognizing method and device based on audio devices of multiple positions of a car. The recognizing method comprises the steps that the answering request of a terminal device in a called state is received; corresponding user information is obtained according to the information, carried in the answering request, of the terminal device; according to the user information, passengers matched with the user information are found out in the passengers who sit on the different positions of the car; and the audio devices of the positions where the found-out passengers are located are started to answer the call of the terminal device.

<CIT> discloses a method for setting playback of a sound recording in a room, the playback providing for a sound signal from a sound source arranged centrally in a virtual sound stage of the sound recording. The sound is output in the room by means of several loudspeakers in a spot area with predetermined sound properties, the sound properties being set by means of respective playback parameters for the loudspeakers.

Therefore, the main aim of the present is to propose a solution to at least partially overcome the above-mentioned inconveniences, and in particular to increase as much as possible the privacy of telephone conversations conducted in a motor vehicle.

This main aim, as well as any further purposes that will emerge more from the description below, are achieved by a system for increasing the privacy of telephone conversations carried out in motor vehicles, the characteristics of which are defined in claim <NUM>.

This main purpose, as well as any additional purposes that will emerge more from the following description, are also achieved by a motor vehicle comprising said system, as defined in claim <NUM>.

Particular embodiments form the subject matter of the dependent claims, the contents of which are intended to form an integral part of this description.

Further features and advantages of the invention will appear from the following detailed description, made purely by way of non-limiting example, with reference to the attached drawings, in which:.

It should be noted that in the following detailed description, identical or similar components, from a structural and/or functional point of view, may have the same or different reference numbers, regardless of whether they are shown in different embodiments of the present invention or in separate parts.

It should also be noted that in order to clearly and concisely describe the present invention, the drawings may not necessarily be to scale and some features of the description may be shown in a somewhat schematic form.

Furthermore, when the term "adapted," or "arranged," or "configured," or "shaped," or "set," or a similar term is possibly used herein, referring to any component as a whole, or to any part of a component or to a combination of components, it should be understood to mean and correspondingly includes the structure and/or the configuration and/or the shape and/or the positioning.

In particular, when such terms refer to electronic hardware or software media, they are to be understood as including circuits or parts of electronic circuits, as well as software/firmware, such as algorithms, routines and programs in general, running and/or residing in any storage medium.

In addition, when the terms "transverse" or "transversely" are used herein they are to be understood as including a direction that is not parallel to the reference part(s)/direction(s)/axis(s) to which they refer, and perpendicularity is to be considered a specific case of transverse direction.

<FIG> schematically illustrates a possible embodiment of a system <NUM> to increase the privacy of telephone conversations conducted onboard a motor vehicle.

An example of a vehicle in the form of an automobile <NUM> is illustrated in <FIG> and <FIG>; in particular, <FIG> shows an example in which two persons <NUM> are seated in the front seats inside the passenger compartment <NUM> and between them, the person <NUM> seated in the position of the driver is involved in a telephone conversation.

In the following description of the system <NUM> according to the invention, for the sake of descriptive simplicity, reference will therefore be made primarily to such a person or individual sitting in the driver's position involved in a telephone conversation, but what is described is equally valid and applicable for any number of individuals <NUM> present on board, whatever position each of them occupies in the passenger compartment <NUM>, such as on the front seat next to the driver's position, or even at the rear, and whoever may be involved in a telephone conversation with an outside party.

As illustrated in <FIG>, the system <NUM> according to the invention includes at least:.

In a possible embodiment of the system <NUM> according to the invention, the plurality of sound sources <NUM> comprises at least one array of loudspeakers.

In a possible embodiment of the system <NUM> according to the invention, the plurality of sound sources <NUM> includes at least one vibrating acoustic device, commonly referred to in the art as a shaker or acoustic exciter.

Clearly, it is possible to realize the system <NUM> according to the invention using both one or more loudspeakers and one or more vibrating acoustic devices.

Specifically, in the realization example in <FIG>, two loudspeaker arrays <NUM> and <NUM> are shown, both of which are installed, for example, at the dashboard <NUM> of the car <NUM>.

Depending on the application, each of these arrays can be realized using a variable number of loudspeakers.

In one possible embodiment, each array <NUM>, <NUM> preferably includes at least three loudspeakers.

In the example configuration shown in <FIG>, there are provided further four side loudspeakers <NUM> and <NUM>, <NUM> and <NUM> installed along the sides of the car <NUM>, such as at the front and rear doors, and an additional loudspeaker <NUM> located at the rear.

In addition, as depicted schematically in <FIG> and <FIG>, additional sound sources <NUM> can be used, e.g., two additional loudspeaker arrays <NUM> and <NUM> at the area between the front seats and the rear seats.

Usefully, in a possible embodiment of the system <NUM> according to the invention, one or more sound sources, whether loudspeakers or vibrating acoustic devices, can be installed at the seats, preferably in the headrests.

Such sources may consist of loudspeakers and vibrating acoustic devices of known types and, according to various application requirements, are configured and operatively associated with each other in such a way as to meet on the whole the coverage requirements of the various frequency ranges of the audio range, thus acting, for example, as woofers, subwoofers et cetera.

Usefully, in the system <NUM> according to the invention, when a telephone conversation is initiated on board the motor vehicle <NUM> with a remote interlocutor external to the motor vehicle <NUM>, the electronic control unit <NUM> is configured, for example on the basis of a signal received in input indicative of the initiation of a telephone conversation with a remote interlocutor external to the motor vehicle <NUM>, so as to:.

In <FIG>, the remote user is schematically represented by the reference number <NUM> and is illustrated as using a portable telephone <NUM>; such a user <NUM> could be in any location, such as in another passenger car, equipped with a system <NUM> according to the invention, or with a common system of a known type, in a building, et cetera.

In one possible example not forming part of the claimed invention, the electronic control unit <NUM> includes at least a first set of predefined equalizers digital filters <NUM>.

According to the claimed invention, the electronic control unit <NUM> is configured to generate in real-time said at least one first set of equalizers digital filters <NUM>.

In particular, in a possible illustrative example of the system <NUM>, the first set of digital filters <NUM> is predefined or, according to the claimed invention, the electronic control unit <NUM> is configured to generate it in real time based on at least a predefined acoustic model M of the passenger compartment <NUM> of the motor vehicle <NUM> or a part thereof.

The acoustic model M allows having, among other things, an acoustic map of the interior of the passenger compartment <NUM> including also the information of the introduced acoustic reverberations thus enabling the a priori knowledge of parameters such as, for example, the time of flight of the sound waves from the various sound sources to the reception points selected as references.

Such a predefined acoustic model M is, for example, saved in a memory unit <NUM> included in the electronic control unit <NUM>, as illustrated in the example in <FIG>, or in a memory associated with it, and can be realized according to modeling techniques and realization solutions widely known in engineering and acoustics that can be easily implemented by a person skilled in the art and are therefore not described in detail here.

Usefully, according to one possible illustrative example, the first set of digital filters <NUM> is predefined or, according to the claimed invention, is generated in real time by the electronic control unit <NUM> on the basis of the emissive characteristics of the one or more chosen sound sources <NUM>, in particular their emission frequency range, and their position within the cabin <NUM>.

In a further possible illustrative example, the first set of digital filters <NUM> is predefined or, according to the claimed invention, is generated in real time by the electronic control unit <NUM> on the basis of a predefined acoustic model of an area of predetermined extent outside the passenger compartment <NUM> in the vicinity of the motor vehicle <NUM>.

In <FIG> such an area is delimited schematically by the dashed line E around car <NUM>, and may extend for example a distance of a few meters, e.g., a radius of <NUM> to <NUM> with respect to the virtual center of the car body.

For example, such an area is mapped in advance, when the vehicle is stationary, by installing around it in the predetermined area E, one or more microphones and measuring the impulse responses at low and low-medium frequencies, for example varying between <NUM> and <NUM>, using for the mapping appropriate mathematical models and modeling techniques widely known in engineering and acoustics easily implementable by a person skilled in the art, and for this reason not described herein in detail.

Such an acoustic model of the external area E can also be stored in the memory unit <NUM> included in the electronic control unit <NUM>, or in an associated memory.

Preferably, in the system <NUM> according to the invention, each set of filters <NUM>, whether prefixed or generated in real time, is defined on the basis of and as a function of both the acoustic models of the passenger compartment <NUM> and the exterior area E, as well as parameters indicative of the emissive characteristics of the sound sources <NUM> and their location within the passenger compartment <NUM>.

In practice, on the basis of these elements, the electronic control unit <NUM> is configured to drive the appropriately chosen one or more sound sources <NUM> by applying to them the predefined or real-time generated set of equalizers digital filters <NUM> so that the sound waves emitted by them and transmitting what is communicated by the remote external user <NUM> during the telephone conversation are selectively directed to the at least one desired listening position A.

In a possible embodiment, the at least one desired listening position A is a predetermined position.

For example, such a position could coincide with a predefined standard position, or with the assumed position of the ears <NUM> of the person usually driving the car <NUM>.

Alternatively, think for example of a family-use automobile, in the system <NUM> according to the invention it is possible to have a plurality of predefined positions, e.g. each corresponding to a different user of the same motor vehicle <NUM>.

Such predefined positions can be stored in the same memory <NUM> of the electronic unit <NUM>, e.g., together with the usual settings that store the position of the seat of the driver or passenger on duty (height of the seat base, inclination of the backrest, headrest, et cetera), e.g., for each possible driver or passenger of the motor vehicle in question.

In this case, the electronic control unit <NUM> may comprise a plurality of predefined sets of digital filters <NUM>, each for a different individual, or it may generate them in real time, and the selection of a predefined set or the real-time calculation of the same may be operated by means of a selector switch or selection function activated by the user of the moment.

In a further possible embodiment, the system <NUM> according to the invention further comprises a tracking system <NUM> which is configured to provide the electronic control unit <NUM> with a signal Si indicative of the current position of the ears <NUM> of an individual <NUM> within the passenger compartment <NUM> relative to a predetermined reference listening position within the passenger compartment <NUM> itself.

In accordance with this embodiment, the electronic control unit <NUM> is further configured to generate in real time, on the basis of said signal Si received in input, as well as on the bases of one or more, preferably all, said predefined acoustic patterns of the passenger compartment and exterior area E, and said emissive characteristics and position of the sound sources <NUM>, at least one further set of equalizers digital filters <NUM> different from said first set of predefined or real-time generated digital filters.

In particular, said at least one further set of digital filters <NUM> is applied by the electronic control unit <NUM> to the one or more selected sound sources <NUM> so that they emit sound waves transmitting what is communicated by the remote user <NUM> directed selectively toward the current position of the ears <NUM> of the individual <NUM> inside the passenger compartment <NUM>.

Clearly, in such embodiment, the first set of digital filters <NUM> generated in real time by the electronic control unit can also be eventually determined as a function of the signal Si.

In practice, the electronic control unit <NUM> is configured to drive one or more of the sound sources <NUM> by means of a corresponding drive signal Sp so as to achieve routing of the emitted sound waves to the current listening position, i.e., the ears <NUM> of the tracked individual <NUM>, relative to a predetermined initial reference position.

In one possible embodiment, the electronic control unit <NUM> is configured to generate said at least one additional set of digital equalizers filters <NUM> by modifying one or more spectral characteristics of one or more filters of the at least one first set of digital filters predefined or as initially computed in real time by the electronic control unit <NUM>.

In practice, the electronic control unit <NUM> is configured for this purpose to operate in the frequency or time domain according to appropriate and per se known engineering processing techniques, and, according to one possible embodiment, the electronic control unit <NUM> modifies the phase and gain of the frequency response of one or more filters of the first set predefined or as initially generated in real time.

Depending on the magnitude of the movement of the head of the individual <NUM> and thus of the position of his/her ears <NUM>, the modification can take place over the entire band of action of the filter or over a portion of it; for example, unit <NUM> modifies phase and gain of high frequencies only if the head has moved a few cm from the reference position, and/or it can modify phase and gain of low frequencies if there is a greater displacement.

As previously mentioned, the <NUM> tracking system is configured to provide a Si signal indicative directly of the current position of the ears <NUM> of each individual <NUM> tracked, referring it relative to at least one predetermined fixed reference position, which may be appropriately chosen within the passenger compartment <NUM>.

In particular, according to a possible embodiment, the system <NUM> comprises a 3D mapping of the passenger compartment <NUM>, such mapping being, for example, also saved in the memory <NUM> included in the electronic control unit <NUM>, or in a memory associated therewith.

According to a possible embodiment, the tracking system <NUM> is configured to provide a signal Si indicative of the current position of the ears <NUM> of the individual <NUM> at least in a virtual plane defined by a first reference axis X extending along the front-back direction of the vehicle <NUM> and a second axis Y, transverse to the first axis X and directed along the junction of the two side flanks of the vehicle <NUM>, schematically represented in <FIG> and <FIG>.

According to a further embodiment, the tracking system <NUM> is configured to provide a signal Si indicative of the current spatial position of the ears <NUM> of individual <NUM> in passenger compartment <NUM>.

In practice, in this embodiment, the current position of the ears <NUM> is defined three-dimensionally, and thus each signal Si generated by the tracking system <NUM> includes, in addition to the data about the computed coordinates related to the current position of the ears <NUM> along the previously mentioned X- and Y-axes, also information about the computed coordinates related to the current position of the ears <NUM> along a third Z-axis transversal to the X- and Y-axes and directed along the floor-to-roof junction of the car <NUM>, as schematically depicted in <FIG>.

According to one possible embodiment, the tracking system <NUM> includes:.

In the exemplary embodiment of <FIG>, there is shown a single camera <NUM> installed, for example, at the rearview mirror <NUM> of the automobile <NUM>.

Clearly, in the system <NUM> according to the invention, it is possible to install such a camera at another location, or to use multiple cameras, for example, a first camera <NUM> intended to capture images related to the heads of persons seated in the front seats, and a second camera <NUM> positioned to capture images of the heads of people seated in the rear seats, or it is also possible to use multiple cameras <NUM> each associated with a corresponding seat of the automobile <NUM>.

In one possible embodiment, the tracking system <NUM> includes at least one stereoscopic camera <NUM>.

The processing unit <NUM> can be located at a camera <NUM>, e.g., integrated with it, or it can be remotely arranged at an appropriate location, e.g., at the rear of the automobile <NUM> where the electronic control unit <NUM> can also be installed, as shown schematically in <FIG>.

In addition, it is possible to use a single processing unit <NUM> that can simultaneously process coordinates relating to the current position of the ears <NUM> of each individual <NUM> tracked present in the passenger compartment <NUM>, providing corresponding signals Si to the electronic control unit <NUM>.

Alternatively, multiple processing units <NUM> each associated with one or more cameras <NUM> can be used.

Conveniently, according to one possible embodiment of the system <NUM> according to the invention, the tracking system <NUM> includes at least one camera <NUM> configured to simultaneously capture images of the heads of two persons <NUM> aboard a vehicle <NUM>, and a processing unit <NUM> that receives such images, providing the electronic control unit <NUM> with corresponding Si signals relative to the current position of the respective ears <NUM> of both persons tracked <NUM>. Accordingly, the electronic control unit <NUM> generates the corresponding filters or sets of digital filters suitable for allowing sound waves to be emitted by the sound sources <NUM> conveyed in a calibrated manner to one of the respective two calculated current positions.

Depending on the specific person who is carrying out the conversation on board the motor vehicle <NUM>, switching between one or more sets of filters relating to, for example, the driver <NUM> or the set(s) relating to a passenger seated, for example, in the seat next to the driver, can be done by means of a selector switch in the system <NUM> itself, which allows switching between the two positions, with the electronic unit <NUM> selectively identifying, on a case-by-case basis, the sources to be driven and using or generating in real time the digital filters to be applied.

It has been found in practice that the system <NUM> according to the invention achieves the intended aim since it allows, during a telephone conversation, to select appropriately the sound source(s) to be operated, and to drive them by directing the sound waves of received communications to a desired location, whether fixed or variable, significantly reducing acoustic leakage outside the passenger compartment compared to current solutions.

With further advantage, the system <NUM> according to the invention can be used in principle in any type of vehicle with a passenger compartment intended to be occupied by people, and can be easily installed both in new vehicles and, if desired, in vehicles already on the road. Thus, a further object of the present invention relates to a vehicle <NUM> characterized by comprising at least one system <NUM> as described above, and more particularly defined in the appended claims.

Claim 1:
A system (<NUM>) for increasing the privacy of telephone conversations carried out on board of a motor vehicle (<NUM>), comprising at least:
- an electronic control unit (<NUM>) suitable to be mounted on board of the motor vehicle;
- a plurality of sound sources (<NUM>) suitable to be mounted on board the motor vehicle (<NUM>) in predefined positions and suitable for emitting sound waves inside the passenger compartment (<NUM>);
wherein, when onboard the motor vehicle a telephone conversation is initiated with a remote interlocutor (<NUM>) external to the motor vehicle (<NUM>), said electronic control unit (<NUM>) is configured to:
- select, from said plurality of sound sources, one or more sound sources (<NUM>) chosen to emit, inside the passenger compartment (<NUM>), sound waves transmitting what is communicated by the remote interlocutor (<NUM>) during the telephone conversation; and
- drive the one or more sources (<NUM>) selected so that the sound waves emitted by them and transmitting what is communicated by the remote interlocutor (<NUM>) during the telephone conversation are directed towards at least one desired listening position (A) within the passenger compartment (<NUM>) of the motor vehicle (<NUM>);
the system (<NUM>) being characterized in that said electronic control unit (<NUM>) is configured to generate in real time at least a first set of digital filters (<NUM>), said first set of digital filters being generated in real time based on:
- a predefined acoustic model (M) of the passenger compartment (<NUM>) of the motor vehicle (<NUM>) or a part thereof; and
- the emissive characteristics of the one or more sound sources (<NUM>) chosen and their position within the passenger compartment (<NUM>); and
- a predefined acoustic pattern of a predetermined extension area (E) outside the passenger compartment (<NUM>) of the motor vehicle (<NUM>),
wherein the electronic control unit (<NUM>) is configured to drive the appropriately selected one or more sound sources (<NUM>) by applying to them the real-time generated first set of digital filters (<NUM>) so that the sound waves emitted by them and transmitting what is communicated by the remote interlocutor (<NUM>) during the telephone conversation are selectively directed towards the at least one desired listening position (A).