On-board interaction system

Abstract

The invention relates to an on-board interaction system comprising a set of ultrasonic transducers (3) controllable by a control module (5) to generate at least one focused flow of ultrasonic acoustic waves, called an ultrasonic acoustic pulse, configured to interact with at least one destination device (7) provided with a receiver module (9) sensitive to said at least one ultrasonic acoustic pulse.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of ultrasonic transducers. STATE OF THE PRIOR ART

[0002] Ultrasonic transducers have many applications in industry and medicine. They can be used for obstacle detection, defect detection, or sterilization in the pharmaceutical industry. Ultrasonic transducers are also used in medicine for the diagnosis and treatment of various conditions.

[0003] Also known in the prior art are systems comprising ultrasonic transducers for creating a focused ultrasound stream at a point that provides a sensation of touch to a person. Such a system, called a haptic system, comprises a set of individually controllable ultrasonic transducers to generate ultrasonic pulses. A control circuit controls the transmission of the transducers with phase shifts between the different transducers so as to focus the emitted waves at a given focal point. This makes it possible to generate, in the vicinity of the focal point, a pressure strong enough to be felt by a person.

[0004] The object of the present invention is to use ultrasonic transducers in an ingenious way to create new industrial applications. STATEMENT OF THE INVENTION

[0005] This objective is achieved with an on-board interaction system comprising a set of ultrasonic transducers controllable by a control module to generate at least one focused stream of ultrasonic acoustic waves, called an ultrasonic acoustic pulse, configured to interact with at least one destination device provided with a receiver module sensitive to said at least one ultrasonic acoustic pulse.

[0006] This allows interaction (data transfer or remote action) to be carried out between a device integrating the embedded system and a recipient device in complete safety because the interaction can only take place in an emission cone of a given volume, where the ultrasonic acoustic waves propagate.

[0007] According to one embodiment, the on-board interaction system is configured to generate a series of ultrasonic acoustic pulses carrying information.

[0008] This allows data (e.g. Morse code) to be transferred or communicated securely to a fixed or mobile device.

[0009] According to one embodiment, said at least one ultrasonic acoustic pulse carries a directional pressure adapted to actuate a predetermined function in the receiving device.

[0010] This allows for intelligent action to be carried out remotely in complete safety, such as the actuation of one (or more) acoustic membranes, a push button or any sensor sensitive to acoustic pressure emitted by the on-board system.

[0011] Advantageously, the on-board interaction system is intended to be embedded in a mobile or fixed device among the following devices: vehicle, aircraft, machine, remote control device.

[0012] According to yet another embodiment, the embedded interaction system is intended to be embedded in a set of devices to generate a set of elementary interactions whose combination is necessary to create a specific interaction with the recipient device.

[0013] According to one aspect of an embodiment, the set of devices carries a set of data blocks whose concatenation is necessary for the reconstitution of secure information and that each of said set of devices is configured to transfer the data block that it carries to the recipient device which is configured to reconstitute the secure information from the set of data blocks.

[0014] The receiving device receives the data blocks in a sequenced manner so that the overall information can be read. This makes it possible to decrypt a set of data, each of whose sub-parts can be brought by different devices incorporating embedded systems, which, once assembled, constitute the entire information set.

[0015] According to another aspect of an embodiment, the set of devices carries a set of elementary directional pressures whose concatenation is necessary for the reconstitution of a specific action and that each of said set of devices is configured to transfer the elementary directional pressure that it carries to the recipient device.

[0016] Advantageously, the on-board interaction system is intended to generate ultrasonic acoustic pulses configured to interact with several recipient devices.

[0017] Advantageously, the ultrasonic transducers are PMUT type piezoelectric transducers arranged in a set of matrices and sub-matrices.

[0018] Advantageously, the control module is configured to control the emission of ultrasonic pulses from the sub-matrices with phase shifts between the different sub-matrices so as to focus the emitted waves at a given point in space.

[0019] Sub-matrix control reduces technological routing and therefore optimizes surface integration. This makes it possible to generate high acoustic pressure from a smaller surface area.

[0020] In one aspect, each ultrasonic transducer includes a flexible membrane suspended on a rigid support and a piezoelectric conversion element attached to the flexible membrane.

[0021] The invention also relates to a recipient device comprising a receiver module configured to capture said at least one ultrasonic acoustic pulse emitted by the on-board interaction system according to any one of the above characteristics. The recipient device may be included in a mobile or fixed device.

[0022] Advantageously, the recipient device includes an on-board interaction system.

[0023] The invention also relates to a mobile or fixed device comprising an on-board interaction system according to any one of the above characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be better understood by reading the description of exemplary embodiments given purely for informational purposes and in no way limiting, with reference to the appended drawings in which: There Fig. 1schematically illustrates an on-board interaction system, according to one embodiment of the invention; The Fig. 2 schematically illustrates an ultrasonic transducer of the haptic interface of the Fig. 1 ; There Fig. 3 illustrates a pressure curve in Pa as a function of distance in cm for a silicon PMUT transducer; The Fig. 4 schematically illustrates the control of the ultrasonic transducers by the control module; The Fig. 5 schematically illustrates an on-board interaction system, according to first and second preferred embodiments of the invention; and The Fig. 6 schematically illustrates a particular application of the on-board interaction system, according to one embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The concept behind the invention is to propose an embedded system comprising ultrasonic transducers to transmit data or activate a specific function remotely and securely.

[0026] There Fig. 1 schematically illustrates an on-board interaction system, according to one embodiment of the invention.

[0027] The embedded interaction system is suitable for being embedded in a mobile or fixed device 2 such as a vehicle, aircraft, drone, machine, remote control device, etc.

[0028] According to the invention, the on-board interaction system 1 comprises a set of ultrasonic transducers 3 which are advantageously arranged in a set of matrices or sub-matrices 4.

[0029] The set of ultrasonic transducers 3 is controllable by a control module 5 to generate at least one focused stream of ultrasonic acoustic waves, called an ultrasonic acoustic pulse. The frequency of the ultrasonic pulses may be between 20 kHz and 10 THz.

[0030] Each ultrasonic acoustic pulse is configured to interact with at least one destination device 7 provided with a receiver module 9 sensitive to the ultrasonic acoustic pulse emitted by the on-board interaction system 1. The receiver module 9 comprises sensors 11 which transform the acoustic pulse into an electrical signal. These sensors 11 may also be acoustic transducers. The destination device 7 may be a mobile or fixed device which may also comprise an on-board interaction system.

[0031] By 'interaction' between the on-board interaction system 1 and the receiver module 9 is meant a remote mechanical action, a data transfer or a communication link.

[0032] This interaction between a device 2 integrating the on-board interaction system 1 and the destination device 7 can only take place in an emission cone 13 of given volume, where the ultrasonic acoustic waves propagate. Thus, the interaction is inviolable outside this emission cone 13 which is very limited in space. This allows the interaction to be carried out in complete safety.

[0033] According to one embodiment aspect, the embedded interaction system 1 can be embedded in a set of mobile devices 2 to generate a set of elementary interactions whose combination is necessary to create a specific interaction with the destination device 7. This provides greater security to the action carried out on the receiving device 7.

[0034] Furthermore, the control module 5 is an electronic circuit integrated into the on-board interaction system 1. Alternatively, the control module 5 may be a software application or a circuit included in the device 2 integrating the on-board interaction system 1.

[0035] Furthermore, the on-board interaction system 1 comprises a power source 15 intended to supply a voltage to the ultrasonic transducers 3 and possibly to the control module 5 when the latter is also included in the on-board interaction system 1. Alternatively, the power source 15 may be included in the apparatus 2 integrating the on-board interaction system 1.

[0036] It should be noted that for certain applications, the control module 5 can even be integrated into an external device linked to the on-board interaction system 1.

[0037] According to one aspect of an embodiment, the ultrasonic transducers 3 are micromachined piezoelectric ultrasonic transducers, called PMUTs (Piezoelectric Micromachined Ultrasonic Transducers). The PMUT transducers may be made of ceramic or silicon. Other types of transducers may be used.

[0038] There Fig. 2schematically illustrates an ultrasonic transducer used in the on-board interaction system of the Fig. 1 .

[0039] This example concerns a PMUT 3 transducer comprising a flexible membrane 15 suspended by its periphery on a rigid support 17. The rigid support 17 is for example made of silicon or ceramic. The membrane 15 is fixed, by its lower face, on the upper face of the support 17. The membrane 15 can have a circular, rectangular, or square shape.

[0040] The PMUT transducer 3 further comprises a piezoelectric conversion element 19 fixed to the membrane, on its upper face side. The piezoelectric conversion element comprises two electrodes 21a, 21b.

[0041] The application of a voltage between the electrodes 21a, 21b of the piezoelectric conversion element 19 causes a deformation of the membrane 15 making it possible to generate an ultrasonic acoustic wave. Conversely, a deformation of the membrane 15 generates a voltage which can be used to measure an ultrasonic acoustic wave received by the PMUT transducer 3. This type of transducer is described in detail in the applicant's patent application FR3092680.

[0042] A PMUT 3 transducer can operate at different ultrasonic frequencies depending on its size or the technology used (silicon, ceramic or other). As a non-limiting example, we consider here the case of a silicon-type PMUT transducer, operating at 100kHz.

[0043] In fact, the Fig. 3 illustrates the pressure curve in Pa as a function of distance in cm for a silicon PMUT transducer.

[0044] More specifically, this curve is derived from measurements made for a single PMUT 3 transducer at 100kHz operating under a driving voltage of 5V. For example, the curve shows that the PMUT 3 transducer generates an acoustic pressure of the order of 0.15 Pa at a distance of 30 cm.

[0045] It should be noted that the acoustic pressure increases almost linearly with increasing voltage. Thus, for a driving voltage of 48 V, the PMUT 3 transducer generates an acoustic pressure of around 1.45 Pa at a distance of 30 cm.

[0046] Furthermore, the pressures add up almost linearly. Thus, using, for example, 140 PMUT transducers, a pressure of the order of 200 Pa at 30 cm can be obtained. A pressure of 200 Pa is taken here just as an indication knowing that it is the pressure that produces a haptic effect. Of course, the receiving module 9 can be sensitive to a pressure lower than 200 Pa.

[0047] The diameter of a circular PMUT transducer is of the order of 800 µm for a silicon type transducer and is of the order of 5 mm for a ceramic type transducer. It will be noted that the diameter depends on the stiffness of the membrane 15, linked to its thickness and its constituent materials. The diameters considered above are indicative and taken as an example in the dimensioning of a matrix or sub-matrix 4 of PMUT transducers 3.

[0048] Thus, using silicon type PMUT transducers and for a gap of the order of 300 µm between the membranes 15 of the neighboring transducers 3, it is possible to construct a matrix 4 of transducers 3 of the order of 1.5 x 1.5 cm 2< generating a pressure of 200 Pa at a distance of 30 cm. It will be noted that the gap of 300 µm between membranes is an indicative gap which is sufficient to allow solidity of the matrix 4 while keeping the membranes close to each other.

[0049] The dimensions of the matrices and / or sub-matrices 4 of transducers 3 can be determined according to the emission frequencies of the PMUT transducers, the technology used (silicon or ceramic), the driving voltage thereof, and the sensitivity of the receiver modules 9.

[0050] The table below shows the sizing of some configurations. The first column indicates the technology used (silicon or ceramic), the second column indicates the surface area of ​​a transducer array, the third column indicates the driving voltage, the fourth column indicates the distance for a pressure of 200 Pa, the fifth and sixth columns indicate the pressures exerted at 30 cm and 50 cm respectively, the seventh column indicates the number of transducers forming the array, and the eighth column indicates the diameter of each transducer. Techno Matrix surface Driving voltage Distance P = 200 Pa Pressure at 30 cm Pressure at 50 cm Number of transducers Transducer diameter PMUT piezo ceramic 4.5×4.5 cm 2< 12 V 16 cm 107 Pa 62.9 Pa 16 5 mm 4.5×4.5 cm 2< 48 V 62 cm 428 Pa 252 Pa 16 5 mm 16×16 cm 2< 12 V 215 cm 1.7 kPa 1.0 kPa 256 5 mm 16×16 cm 2< 48 V 598 cm 6.8 kPa 4.0 kPa 256 5 mm Techno Matrix surface Driving voltage Distance P = 200 Pa Pressure at 30 cm Pressure at 50 cm Number of transducers Transducer diameter PMUT AIN thin layer 1×1 cm 2< 12 V 1.1 cm 6.8 Pa 3.4 Pa 36 800 µm 1×1 cm 2< 48 V 5 cm 27.2 Pa 13.3 Pa 36 800 µm 7×7 cm 2< 12 V 60 cm 0.52 kPa 0.27 kPa 2809 800 µm 7×7 cm 2< 48 V 131 cm 2.08 kPa 1.06 kPa 2809 800 µm

[0051] Thus, depending on the desired application, we can have a small, lightweight matrix with low driving voltage which is very suitable for an embedded system 1. The matrix 4 of transducers can be sized to have an action between a few centimeters to several meters depending on the driving voltage and the sensitivity of the receiver module 9.

[0052] There Fig. 4 schematically illustrates the control of the ultrasonic transducers by the control module.

[0053] The control module 5 is configured to control the sub-matrices 4 of transducers 3 with phase shifts between the different sub-matrices 4 so as to focus the flow of acoustic waves emitted at a focusing point 23 at a predetermined distance. This distance may for example be between 1 cm and 300 cm. This makes it possible to generate, in the vicinity of the focusing point, a pressure strong enough to be picked up by the receiver module 9.

[0054] Furthermore, the power source 15 is configured to provide the transducers 3 with a driving voltage that can be between 5V and 50V. Advantageously, a driving track is used for each sub-matrix 4. Thus, each driving track groups together a plurality of transducers 3, which reduces the technological routing and optimizes the surface integration while allowing the acoustic beamforming technique to be carried out.

[0055] Thus, the on-board interaction system 1 can generate a high acoustic pressure (of the order of 200 Pa) while presenting a high surface integration (from a few mm2 to a few cm2) of transducers 3 and a long range (from a few centimeters to several meters).

[0056] There Fig. 5 schematically illustrates an on-board interaction system, according to first and second preferred embodiments of the invention.

[0057] The example of the Fig. 5 shows a device 2 (e.g., a mobile object) integrating an embedded interaction system 1.

[0058] According to the first embodiment, the on-board interaction system 1 is configured to generate a series of ultrasonic acoustic pulses carrying information intended to be transmitted to a destination device 7. The series of ultrasonic acoustic pulses comprises pulses configured according to a predetermined code, for example like Morse code, understandable by the destination device 7.

[0059] More particularly, the control module 5 in association with a memory 25 storing the information and the coding of acoustic pulses, transforms the digital data into electrical signals and accordingly controls the sub-matrices 4 of ultrasonic transducers 3 according to the description in relation to the Fig. 4 The memory 25 may be included in the control module 5, in the on-board interaction system 1 or in the device 2 incorporating this system 1.

[0060] Upon receipt of the series of ultrasonic acoustic pulses, the receiver module 9 of the destination device 7 transforms these pulses into electrical signals. These signals are then processed and retransformed into digital data by an electronic processing circuit 27 integrated in the destination device 7.

[0061] Thus, data can be transmitted securely through a limited transmission cone 13 from the device 2 integrating the on-board interaction system 1 to the destination device 7.

[0062] Furthermore, the destination device 7 may also include an on-board interaction system 1 allowing the latter to also transmit data to the device 2, thus generating a dialogue between them.

[0063] According to a particular aspect of this first embodiment, the embedded interaction system 1 is intended to be embedded in a set of devices 2 transporting a set of data blocks whose concatenation is necessary for the reconstitution of secure information. In this case, each of the set of devices 2 is configured to transfer the data block that it transports to the destination device 7. The latter is configured to reconstitute the secure information from the set of data blocks. This application makes it possible to carry out data encryption.

[0064] According to the second embodiment of the Fig. 5, the on-board interaction system 1 is configured to generate an ultrasonic acoustic pulse carrying a directional pressure (or pressing force) adapted to activate a predetermined function in the destination device 7. For example, the directional pressure can perform a secure and remote mechanical action on a push button, or an acoustic membrane of the receiver module 9, which activates a specific function of the destination device 7.

[0065] Advantageously, the control module 5 is configured to control the sub-matrices 4 of transducers 3 so as to focus the flows of acoustic waves emitted according to determined emission angles to create preferential axes for the emission of the ultrasonic pulses.

[0066] According to a particular application of this embodiment, the on-board interaction system 1 can be integrated into an autonomous mobile device 2 to go into an area that is difficult for a human to access, in order to actuate or activate a certain function.

[0067] According to another particular aspect, the on-board interaction system 1 is intended to generate ultrasonic acoustic pulses configured to interact with several receiving devices 7.

[0068] Furthermore, as previously, the embedded interaction system 1 may be intended to be embedded in a set of devices 2 carrying a set of elementary directional pressures whose sequential concatenation is necessary for the reconstitution of a specific action. In this case, each of the set of devices 2 is configured to transfer the elementary directional pressure that it carries to the destination device 7, thus carrying out an encryption of actions.

[0069] There Fig. 6 schematically illustrates a particular application of the on-board interaction system, according to one embodiment of the invention.

[0070] In this example, the mobile device 2 is a car and the receiving device 7 is a garage door opening mechanism. The embedded interaction system 1 is integrated, for example, in the bumper of the car 2 and the receiving module 9 is integrated in the garage door opening mechanism 7.

[0071] Thus, the opening mechanism 7 is intended to operate the opening of the garage door by emitting an ultrasonic acoustic pulse from the car 2. This action is contactless and the nature of the ultrasonic acoustic pulse is predetermined in a manner specific to the coupling of the two elements: car / door.

Claims

1. Embedded interaction system, characterized in that it comprises a set of ultrasonic transducers (3) controllable by a control module (5) to generate at least one focused flow of ultrasonic acoustic waves, called an ultrasonic acoustic pulse, configured to interact with at least one destination device (7) provided with a receiver module (9) sensitive to said at least one ultrasonic acoustic pulse, the on-board interaction system (1) being intended to be embedded in a set of devices (2) to generate a set of elementary interactions, the combination of which is necessary to create a specific interaction with the destination device (7).

2. System according to claim 1, characterized in that the on-board interaction system (1) is configured to generate a series of ultrasonic acoustic pulses carrying information.

3. System according to claim 1, characterized in thatsaid at least one ultrasonic acoustic pulse carries a directional pressure adapted to actuate a predetermined function in the receiving device (7).

4. System according to any one of the preceding claims, characterized in that the on-board interaction system (1) is intended to be embedded in a mobile or fixed device (2) among the following devices: vehicle, drone, aircraft, machine, remote control device.

5. System according to any one of the preceding claims, characterized in that the set of devices (2) carries a set of data blocks whose concatenation is necessary for the reconstitution of secure information and in that each of said set of devices (2) is configured to transfer the data block that it carries to the recipient device (7) which is configured to reconstruct the secure information from the set of data blocks.

6. System according to any one of the preceding claims, characterized in that the set of devices (2) carries a set of elementary directional pressures whose concatenation is necessary for the reconstitution of a specific action and in that each of said set of devices is configured to transfer the elementary directional pressure that it carries to the recipient device (7).

7. System according to any one of the preceding claims, characterized in that the on-board interaction system (1) is intended to generate ultrasonic acoustic pulses configured to interact with several recipient devices (7).

8. System according to any one of the preceding claims, characterized in that the ultrasonic transducers (3) are PMUT type piezoelectric transducers arranged in a set of matrices and sub-matrices (4).

9. System according to claim 8, characterized in thatthe control module (5) is configured to control the emission of ultrasonic pulses from the sub-matrices (4) with phase shifts between the different sub-matrices (4) so ​​as to focus the emitted waves at a given point in space.

10. System according to any one of the preceding claims, characterized in that each ultrasonic transducer (3) comprises a flexible membrane (15) suspended on a rigid support (17) and a piezoelectric conversion element (19) fixed on the flexible membrane.

11. Recipient device comprising a receiver module configured to capture said at least one ultrasonic acoustic pulse emitted by the on-board interaction system (1) according to any one of claims 1 to 10.

12. Device according to claim 11, characterized in that it is included in a mobile or fixed device.

13. Device according to claim 11 or 12, characterized in thatIt includes an on-board interaction system.

14. Mobile or fixed device characterized in that it comprises an on-board interaction system (1) according to any one of claims 1 to 10.

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