GB2586944A

GB2586944A - Apparatus and method for emitting sounds from a vehicle

Info

Publication number: GB2586944A
Application number: GB1904396.7A
Authority: GB
Inventors: Tomar Ashutosh; Perez Garry
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2021-03-17
Anticipated expiration: 2039-03-29
Also published as: GB201904396D0; GB2586944B

Abstract

Embodiments of the present invention provide a method and apparatus for generating an audio signal from a vehicle. The method comprises generating a control signal configured to, when output to an array of ultrasonic elements mounted to the vehicle, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal and outputting the control signal to the array of ultrasonic elements.

Description

Apparatus and Method for Emitting Sounds from a Vehicle

TECHNICAL FIELD

Aspects of the invention relate to a control system for generating an audio signal from a vehicle, to a system comprising such a control system and an array of ultrasonic elements, to a vehicle and to a method of generating an audio signal from a vehicle.

BACKGROUND

Many vehicles are fitted with warning devices, such as an automobile horn, which emits a loud sound to alert others of the presence of the vehicle.

Typically, these sounds are radiated from the vehicle in all directions, which reflect off various surfaces in the environment around the vehicle. This can make it difficult for those hearing the sound to quickly determine where the sound has originated from.

It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention may be understood with reference to the appended claims.

In an aspect, there is an apparatus for emitting sounds from a vehicle. The apparatus comprises a substrate, wherein the substrate is a vehicle body member or the substrate is arranged for attachment to a vehicle body member. The apparatus also comprises an array of ultrasonic elements, the array of ultrasonic elements comprising one or more electrically conductive pathways deposited on the surface of the substrate; wherein the array of ultrasonic elements is configured to generate an ultrasonic wave to become demodulated to an audible frequency in air.

The apparatus is operable to emitted an ultrasonic wave from a vehicle that becomes an audible sound. As the ultrasonic wave is emitted from the vehicle, the wave becomes demodulated in the air in which it propagates to audible frequencies. The ultrasonic wave has a much shorter wavelength than audible sounds, because of the shorter wavelength, the ultrasonic wave can initially propagate in a narrow beam unlike waves at audible frequencies from a conventional audible sound source. This allows highly directional sound to be directed at a target. A highly directional sound may enable the recipient to quickly recognise the origin of the sound. Furthermore, those outside of the beam of the ultrasonic wave may hear little or no sound, meaning overall noise levels may be reduced.

In embodiments, the array of ultrasonic elements may comprise at least one piezo electric film.

In embodiments, the one or more conductive pathways may comprise one or more contact elements in electrical contact with the at least one piezo electric film.

In embodiments, the contact elements may be in electrical contact with at least one piezo electric film to form one or more ultrasonic elements of the array of ultrasonic 15 elements.

In embodiments, the substrate may be a vehicle bumper or the substrate may be configured to be attached to a vehicle bumper.

In embodiments, at least a portion of the conductive pathway may be arranged as a digitated structure on the substrate. This may provide an arrangement that further improves the spacing between elements. Reducing the spacing may further improve the number of elements that can be achieved per area of substrate.

In embodiments, at least two portions of the conductive pathway may be arranged as an interdigitated structure. This may provide an arrangement that further improves the spacing between elements.

In embodiments, the conductive pathway may comprise at least two portions separated by the piezo electric film. This may provide an arrangement that further improves the spacing between portions of conductive pathways and therefore, improve the number of elements that can be achieved per area of substrate.

In embodiments, the array of ultrasonic elements may comprise at least 10, 50, 100, 200, 500 or 1000 elements.

By providing an array with a large number of closely spaced elements, the array may be used as a phased array. Thus, in some embodiments, the apparatus may be operable to focus an ultrasonic wave using beam steering.

In an aspect, there is a control system for generating an audio signal from a vehicle, the control system comprising one or more controllers, the control system configured to: generate a control signal configured to, when output to an array of ultrasonic elements mounted to the vehicle, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal; and output the control signal to the array of ultrasonic elements.

In embodiments, the one or more controllers collectively comprise: at least one electronic processor; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to generate a control signal configured to, when output to an array of ultrasonic elements, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal and output the control signal to the array of ultrasonic elements.

In embodiments, the control system may be configured to generate different control signals for two or more ultrasonic elements of the array of ultrasonic elements, wherein the control signals may differ by one or more of phase, amplitude, frequency, pulse length or pulse shape.

In embodiments, the control system may be configured to change the direction of a wave produced by the array of ultrasonic elements by generating different control signals for two or more ultrasonic elements.

In embodiments, the control system may be configured to: receive an input from a sensor; identify a target in dependence on the received input; determine a target location relative to the array of ultrasonic elements in dependence on the received input; and generate one or more control signals so that the modulated ultrasonic wave is directed at the target.

In embodiments, the control system may be configured to generate a control signal in dependence on the target identified and/or determined target location.

In embodiments, the control system may be configured to generate a control signal so that an audible sound is directed at the target, and wherein the audible sound is determined based on the identified target.

In an aspect, there is a vehicle system comprising the control system described above and an array of ultrasonic elements controlled thereby.

In an aspect, there is a vehicle comprising the control system described above and an array of ultrasonic elements controlled thereby.

In embodiments, the array of ultrasonic elements may be mounted to the front of the vehicle and orientated forwards and downwards.

In an aspect, there is a method of generating an audio signal from a vehicle. The method comprises generating a control signal configured to, when output to an array of ultrasonic elements mounted to the vehicle, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal; and outputting the control signal to the array of ultrasonic elements.

Methods of the invention may provide an audible sound from an ultrasonic wave emitted from a vehicle. This allows highly directional sound to be directed at a target.

Such sound may allow faster recognition of the origin of the sound by the target. Furthermore, those not targeted by the ultrasonic wave may hear little or no sound, meaning overall ambient noise levels produced by the vehicle may be reduced.

In embodiments, a different control signal may be generated to two or more of the ultrasonic elements in the array, wherein the control signals may differ by one or more of phase, amplitude, frequency, pulse length or pulse shape.

In embodiments, different control signals may be generated to two or more of the ultrasonic elements to change the direction of the ultrasonic wave.

In embodiments, the method may comprise receiving an input from a sensor; identifying a target in dependence on the received input; determining a target location relative to the array of ultrasonic elements in dependence on the received input; and generating one or more control signals so that the ultrasonic wave is directed at the target.

In embodiments, generating one or more control signals may comprises generating a control signal in dependence on the target identified and/or determined target location.

In embodiments, generating one or more control signals may comprise generating a control signal so that an audible sound is directed at the target, wherein the audible sound is determined based on the target identified.

In an aspect, there is computer software executable to perform a method of any aspect or embodiment described herein.

In an aspect, there is a non-transitory, computer-readable storage medium storing instructions thereon that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out the method described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of example only, with reference to the accompanying figures.

Figure 1 shows a cross section of an apparatus.

Figure 2 shows a schematic of an apparatus.

Figure 3 shows an alternative apparatus arrangement.

Figure 4 shows an alternative apparatus arrangement.

Figure 5 shows a vehicle comprising an apparatus.

Figure 6 shows a flow chart of a method for emitting sound from a vehicle.

Figure 7 is a simplified example of a control system.

Figure 8 shows a flow chart of an embodiment method for emitting sound from a vehicle.

DETAILED DESCRIPTION

Before describing several embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. It will be apparent to those skilled in the art having the benefit of the present disclosure that the invention is capable of other embodiments and of being practiced or being carried out in various ways.

The term "vehicle" used herein may refer to but is not limited to automobiles. The term vehicle may comprise automobiles with SUV, saloon or estate body types, amongst others. The term vehicle may comprise combustion or electrically propelled vehicles. The term vehicle may comprise user driven or self-driven vehicles. A vehicle may have a forward direction and a rear direction opposite thereto. The forward direction is aligned with the normal direction of travel of the vehicle. A vehicle may have a front, rear and side ends. The front end is the end facing in the forward direction.

The term "vehicle body member" used herein may refer to a body panel of a vehicle, this may comprise an external surface of a vehicle. A non-limiting example of a vehicle body member comprise a bumper of an automobile.

The term "ultrasonic element" used herein may refer to an element capable of converting an electrical signal into an ultrasonic wave and/or capable of converting a mechanical input into an electrical signal. The term "ultrasonic element' used herein may comprise ultrasonic receivers, transmitters or transceivers. A non-limiting example of an "ultrasonic element" comprises a piezo electric element.

The term "ultrasonic" used herein may pertain to a sonic wave of a frequency higher that the human upper audible limit. For example, an ultrasonic wave may comprise a propagating mechanical vibration of the order of 20 kHz or higher.

The term "array" used herein in reference to ultrasonic elements may refer to but is not limited to an arrangement of multiple ultrasonic elements. For example, the array may comprise elements in a one-dimensional linear arrangement or two-dimensional grid arrangement. The spacing of the elements, may be regular, irregular or regularly offset.

The term "substrate" used herein may refer to but is not limited to any substance or material to which or in which a conductive pathway may be applied.

The term "conductive pathway" used herein may refer to but is not limited to any electrically conductive pathway. Non-limiting examples comprise wiring, electrically conductive tracks and solder amongst others. A particular but non-limiting example of a conductive pathway comprises tracks formed from screen printing electrically conductive ink.

The term "film" used herein, may refer to but is not limited to a sheet material of 500 micrometres thickness or less.

The term "electrical contact" used herein may refer to but is not limited to a contact between two objects sufficient to conduct electricity to an extent suitable for use with electronics.

The term "digitated" used herein may refer to an arrangement comprising substantially parallel fingers, for example a in a comb-like arrangement. The term "interdigitated" used herein, may refer to two opposed digitated structures. In particular, the term may refer to an arrangement where the parallel fingers of one digitated arrangement are positioned in the spacing between parallel fingers of a second digitated structure.

Referring to Figure 1A, an embodiment apparatus 100 is shown. The apparatus 100 comprises a substrate 102. An electrically conductive pathway 104 is attached to a top surface of the substrate 102. The conductive pathway in the illustrated embodiment comprises a conductive track 104. A portion of the conductive track 104 functions as a contact element 106. A piezo electric film 108 is placed over at least a portion of the track 104 and substrate panel 102, and is in electrical contact with the contact element 106.

The substrate 102 of the apparatus 100 in figure 1A is shown as a vehicle body member to which the track 104 and piezoelectric film 108 are applied. Thus, in this embodiment, the substrate 102 is also a vehicle body member. However, it is envisioned that the present invention may also encompass embodiments where the substrate is a separate component that is adapted to be attached to a vehicle body member, as shown in figure 1B. In figure 1B, the conductive track 104 is attached to a separate substrate layer 102'. The substrate layer 102' is shown in figure 1B attached to a surface of a vehicle body member 102.

In accordance with the embodiment shown in figure 1A, the substrate 102 may be a vehicle body member. A non-limiting example of a substrate that is a vehicle body member may comprise a polymer front bumper panel for an automobile. A conductive pathway 104 and piezo electric film 108 then may be applied to the surface of the bumper panel. Alternatively, and in accordance with the embodiment shown in figure 1B, the substrate 102' may comprise a sheet or layer of material to which the conductive pathway 104 and piezo electric film 108 are applied. The substrate 102' itself may then be attached to a vehicle body member. In a further non-limiting example, the substrate 102' may be a polymer film with an adhesive backing that is adhered to a vehicle body member (e.g. a front bumper panel) before or after the conductive pathway 104 and optionally the piezo electric film 108 has been applied. In both variants embodied by figures 1A and 13, the substrate 102, 102' functions as a medium to which the conductive pathway 104 and piezo electric film 108 are applied.

The conductive pathway 104 may be provided by any electrically conductive medium that can be applied to a substrate 102, 102'. For example, the conductive pathway 104 may comprise a metallic strip, wiring, or any other element capable of conducting an electrical signal. The conductive pathway 104 may be printed, embedded, adhered, etched into the surface or applied to the substrate by any other known method. Any number of conductive pathways may be applied to the substrate. The term "electrically conductive" may be considered as having a sufficient electrical conductivity to be suitable for use as part of electronic circuitry.

The conductive pathway comprises a plurality of contact elements 106. A contact element 106 may be at least a portion of the conductive pathway 104 that electrically contacts the piezo electric film 108. Thus, the conductive pathway 104 functions to transmit electrical signals to and/or from the piezo electric film 108 via the contact elements 106. The contact elements 106 may therefore be considered as electrodes contacting the piezo electric film 108.

In embodiments, the conductive pathway 104 may be shaped, insulated or otherwise arranged to prevent unwanted portions of the conductive pathway 104 from electrically connecting to the piezo electric film 108. For example, an electrically insulating barrier may be placed over portions of the conductive pathway to electrically insulate it from the piezo electric film 108. Alternatively, the piezo electric film 108 may only be deposited on the contact elements 106, so that no electrical connection is formed with the remainder of the conductive pathway 104. Alternatively, the conductive pathway 104 may be arranged away from the piezo electric film 108, by e.g. by embedding within the substrate 102, 102' or arranging on an opposite surface of the substrate.

The contact elements 106 may be portions of the conductive pathway 104 that are shaped, uninsulated or otherwise arranged to electrically connect to the piezo electric film 108.

In embodiments, the conductive pathway 104 may comprise a pathway comprising one or more of nickel, silver, copper, gold, ink, indium tin oxide, carbon, doped semi-conductors, conductive polymers (e.g. PEDOT), or inks comprising any of the former.

The piezo electric film 108, may comprise a single film applied to the substrate 102 in electrical contact with a plurality of contact elements 106. Alternatively, the piezo electric film may comprise any number of discrete films that are applied to the substrate to make electrical contact with one or more contact elements 106. A piezo electric film may be a thin piece (e.g. between 10 and 300 micrometres) of piezo electric material, which may become strained when an electric field is applied. The piezo electrical film 108 may also generate an electrical charge or potential in response to an applied mechanical stress.

The piezo electric film 108 may comprise a piezo-crystal, piezo-ceramic, piezo-polymer or a hybrid piezo-material. Non-exhaustive examples may comprise quartz, lead zirconate, PVT, semiconductor crystals such as Group III-VI and II-V materials, polyvinylidene fluoride or any other known piezoelectric material. In particular embodiments, the piezoelectric film may comprise polyvinylidene fluoride or a copolymer of vinylidene fluoride and trifluoroethylene. The piezo electric film may comprise a piezoelectric polymer cast as a film less than 500 micrometres thick, or between 10 and 300 micrometres thick, or between 20 to 200 micrometres thick or between 40 and 100 micrometres thick, and or any range comprising any combination of the aforesaid values.

In Figure 1, the piezo electric film 108 is shown over the conductive pathway 104, however, the piezo electric film 108 may alternatively be arranged against the substrate and one or more conductive pathways 104 arranged over the piezo electric film 108.

The piezo electric film 108 may be caused to generate a sonic wave by applying one or more electrical signals to the conductive pathway 104. The contact elements 106 of the conductive pathway 104 may transfer the electrical signal(s) to the piezo electric film 108, causing the piezo electric film 108 to mechanically deform. This mechanical deformation may be induced at frequencies and amplitudes sufficient to generate an ultrasonic wave. Thus, an electric signal may be applied to actuate the piezo electric film, to create an ultrasonic wave. As such the conductive pathways 104, contact elements 106 and piezo electric film 108 collectively form ultrasonic element. The ultrasonic element may emit an ultrasonic wave in a direction that is generally perpendicular to the surface that they are applied to. The piezo electric film 108 may also be mechanically deformed by an incident vibrational wave. Mechanical deformation of the piezo electric film 108 may generate a voltage potential in the piezo electric material, which may result in the generation of an electric signal transmitted in the conductive pathway 104 via contact element 106. Thus, an electric signal may also be created by an incident vibrational wave.

Where the contact element 106 contacts the piezo electric film 108, the resulting arrangement may function to create and or detect vibrational waves. The piezo electric film 108 may function as an ultrasonic transmitter by converting an electrical signal to an ultrasonic wave. Similarly, the piezo electric film 108 may function as an ultrasonic receiver by converting an incident vibrational wave to an electrical signal. Optionally, the piezo electric film 108 may function as an ultrasonic transceiver by being operable to perform both transmitting and receiving functions. An array of ultrasonic elements, each comprising a conductive pathway 104, contact elements 106 and piezo electric film 108 as hereinbefore described, may function as an array of emitters, receivers or sensors. An individual ultrasonic element may be considered as an individual emitter, receiver or sensor.

The apparatus 100 of the invention may contain any number of such ultrasonic elements. Vehicle body members may be produced comprising many ultrasonic elements. For example, a vehicle body panel, such as an automobile bumper, may comprise at least 10, 50, 100, 200, 500 or 1000 ultrasonic elements. Fitting conventional ultrasonic elements, such as conventional parking distance sensors, to a vehicle body member requires a substantial amount of wiring, which prohibits the fitting of ultrasonic elements in large numbers. However, the ultrasonic elements hereinbefore described of the apparatus 100 may be applied with a smaller spacing between the elements than would otherwise be possible with conventional ultrasonic elements. The ultrasonic elements of the apparatus 100 may be arranged in one-dimensional or two-dimensional arrays, these may extend along the width of a vehicle body member and/or optionally along the height of a vehicle body member. The different elements of an array can also be mounted in different orientations, meaning the array can provide greater coverage, and may be used for different functions.

The apparatus 100 has many advantages over existing prior art ultrasonic sensors such as conventional ultrasonic parking sensors. These comprise improved functionality such as substantially increased resolution, improved directional discrimination, redundancy, etc. and improved visual appearance.

The apparatus 100 can be applied to vehicle body members to form an array of elements comprising a large number of individual ultrasonic elements. The apparatus of the present invention provides an array having a large amount of redundancy.

Therefore, the array may still function if some of the ultrasonic elements become damaged. The piezo electric elements of the invention can be closely spaced meaning they can also operate as a phased array.

Furthermore, because the apparatus comprises conductive pathways on a surface of a substrate, with a piezoelectric film thereon, a large number of piezo electric elements can be arranged in an array and may be connected without the need for conventional wiring which would otherwise be prohibit the use of a large number of piezo electric elements in a single panel.

Referring to figure 2, an alternative apparatus 200 comprising an array of ultrasonic elements is shown. Similar to figure 1A, the apparatus comprises a conductive pathway 104, applied to a surface of the substrate 202. A piezo electric film 108 is applied to the conductive pathway 104 to form an electrical connection with a contact element 106 of the conductive pathway 104. In the embodiment shown in figure 2, the substrate 202 is the vehicle body member. The substrate 202 further comprises one or more cavities 204. As shown in figure 2, the cavity 204 is aligned to be coincident to the contact element 106. For example, the centre of the ultrasonic element may be positioned over the centre of the cavity 204. Thus, where an ultrasonic element is formed by a contact element 106 in electrical contact with the piezo electric film 108, the cavity 204 may be arranged behind the ultrasonic element. In embodiments, the substrate may be a layer applied to a vehicle body member, in which case, the cavities 204 may be in the substrate or the vehicle body member. The cavity does not need to be limited to an indentation into the substrate or vehicle body member as shown in figure 2. The cavities may, for example, be formed from material extending above the surface of the substrate or body member, e.g. by applying material in a ring shape to the surface, or by forming the substrate/body member to comprise raised walls.

The cavities may function to provide a volume behind the piezo electric film. In embodiments, this may improve the freedom of vibration of the ultrasonic elements. The cavities 202 may also function to dampen undesirable waves reflected from the vehicle body member or substrate. The cavities may be sized so that a wave from an ultrasonic element and incident to a cavity 202, is reflected out of the cavity 202 such that when the wave returns to the ultrasonic element, it is in-phase with a wave emitted outwards from the ultrasonic element. In an embodiment, the depth of the cavity 202 may be half of the resonant wavelength of the ultrasonic element. Alternatively, the indentation may be sized to dampen or cancel the incident wave. In an embodiment, the cavity 202 may be sized to cancel the wave, or may have a volume determined with a cavity resonance selected in dependence on the resonant frequency of the ultrasonic element.

Referring to figure 3A, an apparatus 300 is shown in plan form. The apparatus 300 comprises a substrate 102, onto which conductive pathways 104a, 104b are arranged.

The embodiment shown in figure 3 comprises two sets of conductive pathways 104a, 104b, each set of pathways 104a, 104b arranged as a digitated structure, comprising parallel branches. In figure 3A, the two digitated arrangements of conductive pathways are arranged so that their parallel branches are interlocking, i.e. interdigitated. The contact elements 106 are located at the end of each of the parallel branches, with the piezo electric film 108 laid over the top of the contact elements 106. In this manner, an ultrasonic element is formed between adjacent pairs of contact elements 106 from each conductive pathway 104a, 104b. Figure 3B shows an alternative arrangement of the two conductive pathways 104a, 104b. Both pathways are arranged as an interdigitated structure, but rather than interlocking, the parallel branches are spaced apart and offset. By arranging the conductive pathways in a digitated arrangement, the contact elements can be spaced closer together allowing for an array with a greater density of ultrasonic elements. This in turn allows a further improvement of resolution to be achieved. The term "digitated structure' may refer to but is not limited to any arrangement comprising parallel terminal conductive pathways, i.e. shaped like a cornb.

Referring to figure 4, an alternative embodiment apparatus 400 is shown comprising a first conductive pathway 104a arranged against a surface of substrate 102. A piezo electric film 108 is arranged over the first conductive pathway 104a. A second conductive pathway 104b is arranged over the piezo electric film 108. Thus, two or more conductive pathways 104a, 104b may be separated by the piezo electric film 108. This arrangement may allow the contact elements 106 to be spaced closer together, allowing for a greater number of ultrasonic elements to be placed on the vehicle body member. In embodiments, where the conductive pathways 104a, 104b are arranged in digitated structures, the conductive pathways 104a, 104b may also be separated by the piezo electric film 108.

In embodiments, the apparatus may comprise an outermost elastomeric coating (not shown). For example, at least one layer of an elastomeric paint, varnish, or a protective layer. The outermost layer may comprise a layer of a lower stiffness than the underlying ultrasonic element, to prevent the layer from significantly restraining oscillation of the ultrasonic element.

Referring to figure 5, an embodiment vehicle 500 is shown. The embodiment vehicle comprises a vehicle body member 501, comprising a apparatus 100 attached thereto.

The vehicle body member 501 shown in figure 5 is the front bumper, however the invention may be applied to any vehicle body member of any suitable vehicle type.

In some embodiments, the body panels may be arranged on any one of the front, rear, left and right sides, vehicle underfloor or vehicle roof. The vehicle may comprise a vehicle body panel comprising ultrasonic arrays directed to emit or receive ultrasonic waves over an arc around the perimeter of the vehicle of substantially 360 degrees, 270 degrees, 180 degrees, 90 degrees or 45 degrees, or an arc in any range formed from any of these preceding values. In embodiments, the vehicle may comprise a plurality of vehicle body panels each comprising element arrays.

In embodiments, the apparatus may be mounted to a vehicle in an orientation that is directed generally forwards and/or downwards. In embodiments, the array may be arranged so that the ultrasonic elements of the apparatus extend in a lateral direction, across at least a portion of the front end of the vehicle.

In embodiments, the array may be formed so that the ultrasonic elements extend across substantially the width of the front end of the vehicle.

In embodiments, the array may comprise a plurality of rows of ultrasonic elements. In embodiments, the rows may be aligned horizontally and/or vertically.

In embodiments, the lateral sides of the vehicle 500 may comprise the apparatus as shown by body member 502 in figure 5. In embodiments, the apparatus may be applied to the vehicle provide coverage of substantially the entire perimeter of a vehicle.

In accordance with embodiments of the invention, it is proposed to use a modulated ultrasonic signal emitted by the array of ultrasonic elements to produce an audible signal.

When ultrasound waves pass through a non-linear medium (e.g. air), the non-linear medium acts as a demodulator, which enables an audible signal to be generated from a modulated ultrasonic signal. For example, modulating the amplitude of an ultrasonic carrier signal with an audio frequency signal, and then emitting the modulated ultrasonic signal from an ultrasonic transducer will result in the audio frequency signal being demodulated as the ultrasonic signal is propagated through the non-linear medium, resulting in an audible signal being generated.

Referring to Figure 6, an example of a method 600 of generating an audio signal, for example from a vehicle, is shown. In the example illustrated in Figure 6, the method 600 comprises generating one or more control signals configured to, when output to an array of ultrasonic elements, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal, at 601. The generated control signal(s) is/are then output to the array of ultrasonic elements at 602.

With reference to Figure 7, there is illustrated a simplified example of a control system 800 such as may be adapted to implement the method of Figure 6 described above.

The control system 800 comprises one or more controllers 810 and is configured to generate a control signal 802 configured to, when output to an array of ultrasonic elements mounted to the vehicle, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal.

It is to be understood that the or each controller 810 can comprise a control unit or computational device having one or more electronic processors (e.g., a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), etc.), and may comprise a single control unit or computational device, or alternatively different functions of the or each controller 810 may be embodied in, or hosted in, different control units or computational devices. As used herein, the term "controller," "control unit," or "computational device" will be understood to include a single controller, control unit, or computational device, and a plurality of controllers, control units, or computational devices collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause the controller 810 to implement the control techniques described herein (including some or all of the functionality required for the method described herein). The set of instructions could be embedded in said one or more electronic processors of the controller 810; or alternatively, the set of instructions could be provided as software to be executed in the controller 810. A first controller or control unit may be implemented in software run on one or more processors. One or more other controllers or control units may be implemented in software run on one or more processors, optionally the same one or more processors as the first controller or control unit. Other arrangements are also useful.

In the example illustrated in Figure 7, the, or each, controller 810 comprises at least one electronic processor 820 having one or more electrical input(s) 822 for receiving one or more input signal(s) 804, such as an input signal from one or more sensors, and one or more electrical output(s) 824 for outputting one or more output signal(s) such as control signal(s) 802. The, or each, controller 810 further comprises at least one memory device 830 electrically coupled to the at least one electronic processor 820 and having instructions 840 stored therein. The at least one electronic processor 820 is configured to access the at least one memory device 830 and execute the instructions 840 thereon so as to generate a control signal configured to, when output to an array of ultrasonic elements, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal and output the control signal to the array of ultrasonic elements.

The, or each, electronic processor 820 may comprise any suitable electronic processor (e.g., a microprocessor, a microcontroller, an ASIC, etc.) that is configured to execute electronic instructions. The, or each, electronic memory device 830 may comprise any suitable memory device and may store a variety of data, information, threshold value(s), lookup tables or other data structures, and/or instructions therein or thereon. In an embodiment, the memory device 830 has information and instructions for software, firmware, programs, algorithms, scripts, applications, etc. stored therein or thereon that may govern all or part of the methodology described herein. The processor, or each, electronic processor 820 may access the memory device 830 and execute and/or use that or those instructions and information to carry out or perform some or all of the functionality and methodology describe herein.

The at least one memory device 830 may comprise a computer-readable storage medium (e.g. a non-transitory or non-transient storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors/computational devices, including, without limitation: a magnetic storage medium (e.g. floppy diskette); optical storage medium (e.g. CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g. EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

Example controllers 810 have been described comprising at least one electronic processor 820 configured to execute electronic instructions stored within at least one memory device 830, which when executed causes the electronic processor(s) 820 to carry out the method as hereinbefore described. However, it will be appreciated that embodiments of the present invention can be realised in any suitable form of hardware, software or a combination of hardware and software. For example, it is contemplated that the present invention is not limited to being implemented by way of programmable processing devices, and that at least some of, and in some embodiments all of, the functionality and or method steps of the present invention may equally be implemented by way of non-programmable hardware, such as by way of non-programmable ASIC, Boolean logic circuitry, etc. A system may be formed from the control system 800 and the apparatus 100 described herein. The control system 800 may be further configured to receive a signal from one or more ultrasonic elements of the array of ultrasonic elements.

The control system 800 may be configured to generate electrical control signals having a periodic shape. The electrical control signal may cause the ultrasonic elements to produce an ultrasonic wave of frequency 20 kHz to 400 kHz, 30 kHz to 120 kHz, 40 kHz to 60 kHz or any combination of the aforesaid ranges.

In embodiments, the control system 800 may generate different control signals for two or more ultrasonic elements of the array of ultrasonic elements. In embodiments, different control signals may be generated for different ultrasonic elements, based on their position in the array of ultrasonic elements. In embodiments, the control signals may differ by one or more of phase, amplitude, frequency, pulse duration or pulse shape.

In an embodiment, the control signals output to ultrasonic elements in the array may differ in phase, based on an elements position in the array. The control system 800 may deliver the same control signal, but different in phase to different elements in the array, or the control system 800 may generate a single control signal, that is delayed by a different extent to each of the elements in the array, depending on their position.

In embodiments, the difference in control signals may be used to change the direction of the ultrasonic wave produced by the array of ultrasonic elements. For example, the phase of control signals provided to individual ultrasonic elements may be varied using, for example, programmable delay units that are controlled to provide beam steering, where the array of ultrasonic elements functions as a phased array.

In embodiments, the wave may be directed using beam steering to direct the wave laterally of vertically. That is, the beam may be directed towards the left or right sides of the vehicle, or directed downwards e.g. towards the ground, or upwards, e.g. towards the horizon.

In embodiments, beam steering may be used to focus ultrasonic waves from the array of ultrasonic elements, to direct the wave to a specific target or region ahead of the array.

As described above, audible sound can be achieved from modulated ultrasound. This occurs when the modulated ultrasound passes through a nonlinear media which acts as a demodulator. Demodulation occurs where an ultrasound signal, such as a beam of ultrasound, has sufficient energy to change the speed of sound of the air through which it is travelling, thus causing the air to behave non-linearly. Where a directed ultrasound signal is used, such as a collimated beam of ultrasound, this results in sound that can be heard only along the path of the ultrasound beam. Using a collimated beam of ultrasound as a carrier signal onto which an audible signal has been modulated, for example by way of amplitude modulation, thus allows a beam of sound to be projected over a long distance that is audible only in a small well-defined area.

Referring to Figure 8, an alternative embodiment of a method 700 of generating an audio signal, for example from a vehicle, is shown. In the example illustrated in Figure 8, the method 700 comprises receiving an input from a sensor, for example a camera or the like, at 701 and identifying a target from the sensor input. An audio signal to be generated may then be determined depending on the target identified. In this manner, different audio signals may be generated in relation to different targets. A location of the target relative to the vehicle and/or an array of ultrasonic elements may also be determined from the received sensor input at 704, and a desired direction for the emission of the audio signal determined at 705. One or more control signals configured to, when output to an array of ultrasonic elements, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal is/are then generated, in dependence on the identified target and determined direction for the audio signal, at 706. The generated control signal(s) is/are then output to the array of ultrasonic elements at 707.

The sensor may be any vehicle sensor. Non-limiting examples include LIDAR, Radar, video cameras, ultrasonic sensors, or the apparatus itself operated as an ultrasonic sensor. Input from the sensor may be received by the controller 801 via the VCU 802.

Input from the sensor may be used to identify a target. The target may include any person animal or object a user of the vehicle may want to alert with an audible noise.

Non-limiting examples of the target may include: a pedestrian close to a road edge or in front of the vehicle: a second vehicle moving towards the vehicle comprising the apparatus; or if the vehicle is an emergency vehicle, any other vehicle near the emergency vehicle.

The input from one or more sensors may be analysed to determine a target. For example, where the sensor is a camera, image recognition may be used to analyse the input from the camera to identify targets such as pedestrians. The input may comprise input from multiple sensor systems. The identification of targets may be performed by the VCU 802 e.g. as part of an autonomous driving system, or may be performed by the controller 801 to the apparatus 100.

Input from one or more sensors may be used to determine the location of the identified target. The determination of target location may be calculated another vehicle module under control of the VCE e.g. an autonomous driving module. The determination of target location may be calculated as part of the step of identifying the target. The determined location may be, for example, coordinates, or an angle on a horizontal plane to the target from the apparatus 100.

In embodiments, the step of generating one or more signals may comprise generating a signal in dependence on the target identified and/or determined target location.

In embodiments, the step of generating one or more signals may comprise generating a signal so that an audible sound is directed at the target, wherein the audible sound is determined based on the target identified.

The target location may be used by the controller to generate a signal to the array of ultrasonic elements to generate a wave directed at the target's location. For example, the controller may generate signals to each of the ultrasonic elements, having appropriate phase delays, so that the generated ultrasonic wave is directed at the target using phased array beam steering.

The controller may also generate a signal based on the identified target, for example the signal may be adapted by the controller so that an ultrasonic wave produced becomes audible to a different sound, depending on the target identified. The signal may also be determined to produce a different audible sound depending on target location.

In embodiments, the identified target may be assigned a value relating to its category, for example; a vehicle, pedestrian, cyclist, or by its location, direction of motion or proximity to the vehicle. A signal may the n be generated based on the category assigned to the identified target. For example, if the identified target is a pedestrian in the road that is at risk of collision, or a second vehicle changing lanes towards the vehicle, an alert sound may be emitted to the target. Whereas if the vehicle is an electric vehicle, and a pedestrian is on the side of the road with no risk of collision, a sound may be emitted to make the pedestrian aware of the presence of the electric vehicle.

The apparatus may perform additional functions as well as the purpose referred to herein. For example, the apparatus may be used as any one of: apparatus for emitting sounds from a vehicle, a parking sensor: a sensor for determining the depth of a vehicle; a sensor for near zone imaging of a vehicle; as a microphone for detecting external sounds.

The apparatus may perform different functionalities depending on the current state of the vehicle. Non-limiting example vehicle state include: where the vehicle is in parking mode, the apparatus may be operated as a parking sensor; where the vehicle is off-road, or moving in traffic, it may be operated as a near zone imaging device for controlling speed and/or steering, when the vehicle is in motion, it may be used to emit sounds; and where the vehicle is occupied, it may be used as a microphone or for emitting sounds.

Where the vehicle is in two concurrent states, changing between functionalities may be operated by the controller or vehicle control unit. For example, where a vehicle in in motion, the apparatus may be used as a near field sensor, however, when the controller identifies a pedestrian or car in a hazardous position, the controller may operate the sensor to emit a warning sound to the pedestrian, before resuming operation as a near field sensor.

It will be appreciated that embodiments of the present invention can be realised in the form of hardware, software or a combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape. It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs that, when executed, implement embodiments of the present invention. Accordingly, embodiments provide a program comprising code for implementing a system or method as claimed in any preceding claim and a machine-readable storage storing such a program. Still further, embodiments of the present invention may be conveyed electronically via any medium such as a communication signal carried over a wired or wireless connection and embodiments suitably encompass the same.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims. 1. 2. 3. 4. 5.

Claims

CLAIMSA control system for generating an audio signal from a vehicle, the control system comprising one or more controllers, the control system configured to: generate a control signal configured to, when output to an array of ultrasonic elements mounted to the vehicle, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal; and output the control signal to the array of ultrasonic elements.
The control system of claim 1, wherein the one or more controllers collectively comprise: at least one electronic processor; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to generate a control signal configured to, when output to an array of ultrasonic elements, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal and output the control signal to the array of ultrasonic elements.
The control system according to claim 1 or claim 2, wherein the control system is configured to generate different control signals for two or more ultrasonic elements of the array of ultrasonic elements, wherein the control signals may differ by one or more of phase, amplitude, frequency, pulse length or pulse shape.
The control system according to any preceding claim, wherein the control system is configured to change the direction of a wave produced by the array of ultrasonic elements by generating different control signals for two or more ultrasonic elements.
The control system according to any preceding claim, wherein the control system is configured to: receive an input from a sensor; identify a target in dependence on the received input; determine a target location relative to the array of ultrasonic elements in dependence on the received input; and generate one or more control signals so that the modulated ultrasonic wave is directed at the target.
6. The control system according to claim 5, wherein the control system is configured to generate a control signal in dependence on the target identified and/or determined target location.
7. The control system according to claim 6, wherein the control system is configured to generate a control signal so that an audible sound is directed at the target, and wherein the audible sound is determined based on the identified target.
8. A vehicle system comprising the control system according to any preceding claims and an array of ultrasonic elements.
9. A vehicle comprising the control system according to any one of claims 1 to 7 and an array of ultrasonic elements.
10. A vehicle according to claim 9, wherein the array of ultrasonic elements is mounted to the front of the vehicle and orientated forwards and downwards.
11. A method of generating an audio signal from a vehicle, the method comprising: generating a control signal configured to, when output to an array of ultrasonic elements mounted to the vehicle, cause the array of ultrasonic elements to generate a modulated ultrasonic signal that is arranged to demodulate as it propagates through air to produce an audible signal; and outputting the control signal to the array of ultrasonic elements.
12. A method according to claim 11, comprising generating a different control signal to two or more of the ultrasonic elements in the array, wherein the signals may differ by one or more of phase, amplitude, frequency, pulse length or pulse shape.
13. A method according to one of claims 11 or 12, comprising generating different control signals to two or more of the ultrasonic elements to change the direction of the ultrasonic wave.
14. A method according to any one of claims 11 to 23, comprising: receiving an input from a sensor; identifying a target in dependence on the received input; determining a target location relative to the array of ultrasonic elements in dependence on the received input; and generating one or more control signals so that the ultrasonic wave is directed at the target.
15. A method according to claim 14, wherein generating one or more control signals comprises generating a control signal in dependence on the target identified and/or determined target location.
16. A method according to claim 11 or 16, wherein generating one or more control signals comprises generating a control signal so that an audible sound is directed at the target, wherein the audible sound is determined based on the target identified.
17. Computer software executable to perform the method of any of claims 11 to 16.
18. A non-transitory, computer-readable storage medium storing instructions thereon that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out the method of any one of claims 11 to 16.