Measuring device with transformer and piezoelectric elements for motor vehicles

Abstract

The invention relates to a device (1) for a parameter for a motor vehicle, comprising a main module (10) and a remote module (20), said main module (10) comprising a control stage (110) and a primary winding (125), said control stage (110) being configured to electrically supply the primary winding (125) from an alternating current so that said primary winding (125) generates a magnetic field varying according to said alternating current, said remote module (20) comprising a secondary winding (215), immersed in said magnetic field when said magnetic field is generated, an external piezoelectric transceiver (218), connected to said secondary winding (215) by wire and configured to emit and receive ultrasonic signals, an internal piezoelectric transceiver (228) configured to emit and receive ultrasonic signals, and a sensitive element (230) configured to measure said parameter.Figure for the abbreviation: Figure 1.

Description

Title of the invention: Measuring device with transformer and piezoelectric elements for motor vehicle technical field

[0001] The present invention relates to the field of automobiles and more particularly concerns a measuring device with transformer and piezoelectric elements for motor vehicles and its method of implementation. Previous technique

[0002] As is known, an electric motor comprises a rotor and a stator. The operation of such a motor causes the rotor and stator to heat up. However, the rotor's temperature rise can lead to performance losses and demagnetization of the magnets inside it beyond a certain temperature, which can result in damage or even motor failure. It is therefore necessary to measure the temperature inside the rotor in order to reduce its speed when the temperature approaches the critical operating limit and thus prevent damage to the motor or its failure.

[0003] Because of its rotation during operation, the rotor temperature is difficult to measure directly by wired temperature probes, so it is estimated by algorithms and models integrated into the motor management system.

[0004] However, these integrated algorithms and models result in measurement errors of up to plus or minus 20°C, which is not satisfactory for controlling the motor in order to avoid damaging it or causing its failure.

[0005] A simple, reliable and effective solution that would at least partially remedy these drawbacks would therefore be advantageous. Description of the invention

[0006] To this end, the invention first relates to a device for measuring a parameter for a motor vehicle, said device comprising a main module and a remote module, said main module comprising a control stage and a primary winding, said control stage being configured to electrically supply the primary winding from an alternating current so that said primary winding generates a magnetic field that varies according to said alternating current, said remote module comprising a secondary winding, immersed in said magnetic field when said magnetic field is generated, an external piezoelectric transceiver, connected to said secondary winding by wire and configured to emit and receive ultrasonic signals, an internal piezoelectric transceiver configured to emit and receive ultrasonic signals, and a sensitive element configured to measure said parameter, to generate a measurement signal comprising at least one value of the measured parameter and to transmit said measurement signal to said internal piezoelectric transceiver, said secondary winding being configured to generate an alternating electric current from the variations of the magnetic field generated by the primary winding and to transmit said electric current to the external piezoelectric transceiver in order to power it, the external piezoelectric transceiver being configured to, when powered by the electric current received from the secondary winding, emit ultrasonic signals to the internal piezoelectric transceiver, said internal piezoelectric transceiver being configured to collect the energy from the ultrasonic signals received from the external piezoelectric transceiver,to electrically power the sensing element from said energy, to receive a measurement signal generated by the sensing element, to extract from said received measurement signal at least one value of the measured parameter, and to control the emission of ultrasonic signals comprising at least one extracted parameter value to the external piezoelectric transceiver, the external piezoelectric transceiver being configured to generate and transmit an alternating current signal comprising at least one extracted measurement value to the secondary winding, the secondary winding being configured to generate a magnetic field when said secondary winding is powered by said alternating current signal, said magnetic field being detected by the primary winding, the control stage being configured to determine at least one measured parameter value from the variations in the magnetic field detected by the primary winding.

[0007] The primary and secondary windings form a transformer. Electrical energy, control commands, and measured values ​​are transmitted between the primary and secondary windings by electromagnetic coupling. The secondary winding is driven by the field received from the primary winding. The received level depends on the coupling factor, which itself depends on the air gap and the turns ratio (number of secondary turns / number of primary turns), which can be adapted according to the intended application or the device's arrangement in the vehicle.

[0008] The device according to the invention makes it possible to perform remote measurements via the remote module by powering the sensing element with energy from signals sent by the main module over a wireless link. Thus, measurements can be taken very close to the magnets, which increases the performance of the electrical machine control. The invention also eliminates the need for metallic barriers such as, for example, the casing and flanges. protective devices that can at least partially block electromagnetic waves such as Wifi or Bluetooth.

[0009] In one embodiment, the internal piezoelectric transceiver is configured to store the energy of the ultrasonic signals received from the external piezoelectric transceiver.

[0010] According to one aspect of the invention, the sensitive element and the internal piezoelectric transceiver are connected by wire or wirelessly.

[0011] In one embodiment, the remote module includes an external communication stage configured to transmit signals containing at least one measured value. The external communication stage may, for example, transmit using a Bluetooth or RFID communication protocol.

[0012] Advantageously, the external piezoelectric transceiver is configured to resonate at least one predetermined frequency and the internal piezoelectric transceiver is configured to resonate at said at least one predetermined frequency.

[0013] The invention also relates to an electric machine for a motor vehicle, said electric machine comprising a stator, a rotor and a measuring device as presented above, said electric machine being configured to be mounted in said vehicle in order to drive the wheels of said vehicle in rotation, electric machine in which the main module is mounted on the stator and the remote module is mounted on the rotor.

[0014] Advantageously, the rotor comprising a shaft having a first shaft portion and a second shaft portion mounted on the stator by a bearing system, the first shaft portion having an end face extending orthogonally to the longitudinal axis of rotation of the rotor, the secondary winding is mounted on said end face, the external piezoelectric transmitter-receiver is mounted on the first shaft portion, the internal piezoelectric transmitter-receiver and the sensing element are mounted inside the rotor and the primary winding is mounted on a portion of the stator facing said secondary winding.

[0015] The invention also relates to a battery for a motor vehicle, comprising a measuring device as previously presented, the remote module being mounted so that the sensitive element is placed in said battery.

[0016] The invention also relates to a group of batteries for a motor vehicle, comprising a measuring device as previously described, comprising at least one remote module mounted so that the sensing element is placed in at least one of the batteries of the battery group.

[0017] The invention also relates to a fuel cell for a motor vehicle comprising a measuring device as previously presented, the remote module being mounted so that the sensitive element is placed in said fuel cell.

[0018] The invention also relates to a motor vehicle comprising a measuring device as previously described.

[0019] In one embodiment, the vehicle is an electric or hybrid electric vehicle and includes an electric machine as described above.

[0020] In one embodiment, the vehicle includes a battery or a group of batteries or a fuel cell as described above.

[0021] The invention also relates to a method for measuring a parameter in a motor vehicle using a measuring device as described above, said method comprising the steps of:

[0022] - power supply to the primary winding by the control stage with a alternating current,

[0023] - generation by the primary winding of a magnetic field varying according to said alternating current,

[0024] - generation by the secondary winding of an electric supply current alternating current based on variations in the magnetic field generated by the primary winding,

[0025] - transmission of said electrical supply current by the secondary winding to the external piezoelectric transceiver,

[0026] - emission, by the external piezoelectric transceiver, of an ultrasonic signal food,

[0027] - reception, by the internal piezoelectric transceiver of the ultrasonic signal power supply emitted,

[0028] - power supply to the sensing element by the transceiver internal piezoelectric with an electric current generated from the received ultrasonic power supply signal so that said sensitive element performs at least one measurement of the parameter,

[0029] - measurement of the parameter by the sensitive element,

[0030] - generation of a measurement signal by the sensitive element, said measurement signal including at least one value of the measured parameter,

[0031] - transmission, by the sensitive element, of the measurement signal to the transceiver internal,

[0032] - reception, by the internal transceiver, of the measurement signal generated by the sensitive element,

[0033] - conversion of the received measurement signal into an ultrasonic measurement signal,

[0034] - emission, by the internal transceiver, of said ultrasonic measurement signal,

[0035] - reception by the external piezoelectric transceiver of the ultrasonic signal of measure issued

[0036] - conversion of the received ultrasonic measurement signal into an excitation current signal alternative including at least one value of the measured parameter,

[0037] - supplying the secondary winding with said excitation current signal,

[0038] - generation of a magnetic field by the secondary winding from said signal of excitation current,

[0039] - detection, by the primary winding, of variations in the magnetic field generated by the secondary winding,

[0040] - determination, by the control stage, of at least one parameter value measured from the variations in the magnetic field detected by the primary winding.

[0041] In one embodiment, the internal piezoelectric transceiver is configured to collect and store the electrical energy of the ultrasonic signals received from the external piezoelectric transceiver.

[0042] Advantageously, the energy of the received signals is stored until a predetermined threshold is reached before the sensing element is electrically powered from the stored energy. Brief description of the drawings

[0043] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

[0044] [Fig-1] Fig. 1 schematically and functionally illustrates a first embodiment of the measuring device according to the invention.

[0045] [Fig.2] Fig.2 schematically illustrates, in a functional manner, a second embodiment of the measuring device according to the invention.

[0046] [Fig.3] Fig.3 schematically illustrates an example of an electrical machine according to the invention.

[0047] [Fig.4] Fig.4 schematically illustrates an example of a battery according to the invention.

[0048] [Fig. 5] [Fig. 5] schematically illustrates an example of a battery group according to the invention.

[0049] [Fig.6] Fig.6 schematically illustrates an example of a fuel cell according to the invention.

[0050] [Fig.7] Fig.7 schematically illustrates one embodiment of the process according to the invention. Description of the implementation methods

[0051] Figure 1 is an example of a measuring device 1 according to the invention. The device 1 is intended to be mounted in a motor vehicle.

[0052] The device 1 comprises a main module 10 and a remote module 20.

[0053] Main Module 10

[0054] The main module 10 comprises a control stage 110 and a primary winding 125 electrically connected to each other.

[0055] The primary winding 125 is preferably a PCB winding or a wire winding.

[0056] The control stage 110 is configured to electrically supply the primary winding 125 from an alternating current, for example supplied by an electrical power source via a cable connected to an electrical network (not shown).

[0057] The power supply to the primary winding 125 enables said primary winding 125 to generate a variable magnetic field which is a function of said alternating supply current.

[0058] Remote Module 20

[0059] The remote module 20 includes a secondary winding 215, an external piezoelectric transceiver 218, an internal piezoelectric transceiver 228 and a sensitive element 230.

[0060] The remote module 20 can include more than one sensitive element 230 to measure several parameters. The parameter(s) measured can, for example, be air temperature, air pressure, humidity level, the intensity of an electric current, a mechanical force (stress), a torque, etc.

[0061] The secondary winding 215 is immersed in the magnetic field generated by the primary winding 125 when a magnetic field is generated by the primary winding 125. The secondary winding 215 is preferably a PCB winding or a wire winding and is connected to the external piezoelectric transceiver 218 by wire.

[0062] The secondary winding 215 is configured to generate an alternating electric current from the variations of the magnetic field generated by the primary winding 125 and to transmit the electric current to the external piezoelectric transmitter-receiver 218 in order to power it electrically.

[0063] When electrically powered by the secondary winding 215, the external piezoelectric transceiver 218 is configured to emit ultrasonic signals to the internal piezoelectric transceiver 228 and to receive ultrasonic signals emitted by the internal piezoelectric transceiver 228.

[0064] The internal piezoelectric transceiver 228 is configured to emit ultrasonic signals to the external piezoelectric transceiver 218 and to receive ultrasonic signals emitted by the external piezoelectric transceiver 218.

[0065] The internal piezoelectric transceiver 228 is configured to collect energy from the ultrasonic signals received from the external piezoelectric transceiver 218, which powers it electrically, and to power the sensitive element 230 electrically from said energy.

[0066] The internal piezoelectric transceiver 228 and the sensitive element 230 are connected by wire or wirelessly.

[0067] The internal piezoelectric transceiver 228 is configured to receive a measurement signal S generated by the sensitive element 230, to extract from said measurement signal S at least one value of the measured parameter and to control the emission of ultrasonic signals including at least one extracted parameter value to the external piezoelectric transceiver 218.

[0068] The sensitive element 230 is configured to measure a parameter such as, for example, air temperature, air pressure, humidity level, intensity of an electric current, mechanical force (stress), torque, etc.

[0069] The sensitive element 230 is configured to generate a measurement signal S comprising at least one value of the measured parameter and to transmit said measurement signal S to the internal piezoelectric transceiver 228.

[0070] The external piezoelectric transceiver 218 is configured to generate and transmit an alternating current signal comprising at least one measurement value extracted from the secondary winding 215.

[0071] The secondary winding 215 is configured to generate a magnetic field when said secondary winding 215 is powered by said alternating current signal, said magnetic field being detected by the primary winding 125.

[0072] The control stage 110 is configured to determine at least one parameter value measured from the variations in the magnetic field detected by the primary winding 125.

[0073] In one embodiment:

[0074] - the control stage 110 is configured to generate a signal at at least one predetermined frequency and to deliver the generated signal to the primary winding 125, and

[0075] - the internal piezoelectric transceiver 228 is configured to resonate at minus one predetermined frequency, preferably two predetermined frequencies, for example 200 kHz and 2 MHz,

[0076] - the external piezoelectric transceiver 218 is configured to resonate at said at least a predetermined frequency in order to optimize the transmission rate of ultrasonic signals and the consumption of electrical current.

[0077] In one embodiment, the internal piezoelectric transceiver 228 is configured to store the energy of the ultrasonic signals received from the external piezoelectric transceiver 218. Preferably, the piezoelectric transceiver internal 228 is configured to electrically power the sensitive element 230 from the stored energy only when a predetermined energy storage threshold has been reached.

[0078] In one embodiment, illustrated in [Fig. 2], the remote module 20 includes an external communication stage 240 configured to transmit signals containing at least one measured value. This transmission can, for example, be carried out on a Bluetooth or RFID communication interface, which are known per se. In this case, the external communication stage 240 preferably includes a microcontroller enabling the implementation of this transmission function.

[0079] Examples of use of the measuring device according to the invention

[0080] Example 1: 300 electric machine

[0081] Figure 3 is an example of an electric machine 300 for a motor vehicle. The electric machine 300 is configured to be mounted in the vehicle in order to drive the wheels of said vehicle in rotation.

[0082] The electric machine 300 comprises a stator 310, a rotor 320 and a device 1 as previously presented.

[0083] The main module 10 is mounted on the stator 310 and the remote module 20 is mounted on the rotor 320.

[0084] The rotor 320 is configured to rotate around a longitudinal axis X.

[0085] In this example, the rotor 320 includes a material shaft 321 extending along the longitudinal axis X of rotation and comprising a first portion of axis 321A and a second portion of axis 321B connected to the stator 310 by means of a bearing system 315.

[0086] The first shaft portion 321A comprises an end face 321A1 extending orthogonally to the longitudinal axis X of rotation of the rotor 320. The secondary winding 215 is mounted on said end face 321A1, and the external piezoelectric transceiver 218 is mounted on the first shaft portion 321A. The internal piezoelectric transceiver 228 is mounted inside the rotor 320. The primary winding 125 is mounted on a portion of the stator 310 facing the secondary winding 215.

[0087] Example 2: 400 battery

[0088] The [Fig.4] is an example of a 400 battery for a motor vehicle.

[0089] The main module 10 is placed at a distance from the battery 400 while the module Remote unit 20 is mounted on battery 400: the secondary winding 215 and the external piezoelectric transceiver 218 are outside, and the internal piezoelectric transceiver 228 and the sensing element 230 are placed inside battery 400 in order to measure a parameter inside said battery 400, by Examples include temperature or pressure, humidity level, the intensity of an electric current, a mechanical force (stress), a torque, or other factors.

[0090] Example 3: 500 battery group

[0091] The [Fig.5] is an example of a 500 battery group for a motor vehicle.

[0092] The main module 10 is placed at a distance from the battery group 500 while one or more remote modules 20 are mounted respectively on one or more of the batteries 400 of the battery group 500 so that the sensitive element 230 of each remote module 20 measures a parameter inside each battery 400 similarly to the previous example, for example temperature or pressure.

[0093] Example 4: 600 fuel cell

[0094] The [Fig.6] is an example of a 600 fuel cell for a motor vehicle.

[0095] The main module 10 is placed at a distance from the fuel cell 600 while that the remote module 20 is mounted on the fuel cell 600 so that the sensing element 230 measures a parameter inside said fuel cell 600, for example at the level of the air supply circuit for the membranes of the fuel cell 600, similarly to the previous examples. Here again, the parameter(s) measured can, for example, be temperature, pressure, humidity, the intensity of an electric current, a mechanical force (stress) or a torque.

[0096] Example of implementation

[0097] An example of the implementation of device 1 will now be described with reference to [Fig. 7]. In this non-limiting example, the parameter to be measured may, for example, be the temperature, in particular inside a rotor 320 of an electric machine 300.

[0098] First, in a step El, when it is necessary to measure the parameter, the control stage 110 of the main module 10 electrically supplies the primary winding 125 with an alternating SCS source electric current.

[0099] The primary winding 125 then generates in a step E2 a magnetic field varying according to said alternating current.

[0100] As a result, the secondary winding 215 generates in a step E3 an alternating SCA supply electric current from the variations of the magnetic field generated by the primary winding 125 and then transmits this SCA supply electric current to the external piezoelectric transmitter-receiver 218 in a step E4.

[0101] The external piezoelectric transceiver 218, powered by the SCA supply electric current received from the secondary winding 125, then emits an ultrasonic supply signal SU1 in a step E5.

[0102] This ultrasonic power supply signal SU1 is received, in a step E6, by the internal piezoelectric transceiver 228, which converts the energy of the received ultrasonic signal into an electric current to electrically power the sensing element 230 in a step E7 so that said sensitive element 230 performs at least one measurement of the parameter in a step E8.

[0103] Once the measurement has been carried out, the sensitive element 230 generates, in a step E9, a measurement signal S comprising at least one value of the measured parameter and then transmits this measurement signal S in a step E10 to the internal piezoelectric transceiver 228, which receives it in a step Eli.

[0104] The internal piezoelectric transceiver 228 then converts the received measurement signal S into an ultrasonic measurement signal SU2 in a step E12 and then transmits this ultrasonic measurement signal SU2 to the external piezoelectric transceiver 218 in a step El3.

[0105] The external piezoelectric transceiver 218 receives the ultrasonic measurement signal SU2 in a step E14 and then converts the received ultrasonic measurement signal SU2 into an alternating excitation current signal SCE comprising at least one value of the measured parameter in a step E15.

[0106] The external piezoelectric transceiver 218 then uses this alternating excitation current signal SCE to power the secondary winding 215 in a step E16 so that said secondary winding 215 generates a magnetic field in a step E17.

[0107] The primary winding 125 then detects the variations in the magnetic field generated by the secondary winding 215 in a step El8 by generating an output current representative of these variations, which it transmits to the control stage 110.

[0108] The control stage 110 then determines in a step E19 at least one measured parameter value from the variations detected by the primary winding 125, these variations being representative of at least one measured parameter value contained in the alternating excitation current signal SCE supplying the secondary winding 125.

[0109] The invention therefore makes it possible to measure a parameter using a remote module 20 powered remotely by electrical energy, thus avoiding the use of a battery to be changed, which is particularly advantageous in the case of an electric machine rotor.

Claims

1. Demands Device (1) for measuring a parameter for a motor vehicle, said device (1) comprising a main module (10) and a remote module (20), said main module (10) comprising a control stage (110) and a primary winding (125), said control stage (110) being configured to electrically supply the primary winding (125) with an alternating current so that said primary winding (125) generates a magnetic field that varies according to said alternating current, said remote module (20) comprising a secondary winding (215), immersed in said magnetic field when said magnetic field is generated, an external piezoelectric transceiver (218), connected to said secondary winding (215) by wire and configured to emit and receive ultrasonic signals, an internal piezoelectric transceiver (228) configured to emit and receive ultrasonic signals, and a sensing element (230) configured to measure said parameter,to generate a measurement signal (S) comprising at least one value of the measured parameter and to transmit said measurement signal (S) to said internal piezoelectric transceiver (228), said secondary winding (215) being configured to generate an alternating electric current from the variations of the magnetic field generated by the primary winding (125) and to transmit said electric current to the external piezoelectric transceiver (218) in order to power it electrically, the external piezoelectric transceiver (218) being configured to, when powered electrically by the electric current received from the secondary winding (215), emit ultrasonic signals to the internal piezoelectric transceiver (228), said internal piezoelectric transceiver (228) being configured to collect the energy of the ultrasonic signals received from the external piezoelectric transceiver (218),to electrically power the sensitive element (230) from said energy, to receive a measurement signal (S) generated by the sensitive element (230), to extract from said measurement signal (S) received at least one value of the measured parameter and to control the emission of ultrasonic signals comprising at least one extracted parameter value to the external piezoelectric transceiver (218), the external piezoelectric transceiver (218) being configured to generate and transmit an alternating current signal comprising at least one measurement value extracted at the secondary winding (215), the secondary winding (215) being configured to generate a magnetic field when said secondary winding (215) is powered by said alternating current signal, said magnetic field being detected by the primary winding (125), the control stage (110) being configured to determine at least one parameter value measured from the variations in the magnetic field detected by the primary winding (125).

2. Device (1) according to claim 1, wherein the internal piezoelectric transceiver (228) is configured to store the energy of the ultrasonic signals received from the external piezoelectric transceiver (218).

3. Device (1) according to any one of the preceding claims, wherein the sensing element (230) and the internal piezoelectric transceiver (228) are connected by wire or wirelessly.

4. Device (1) according to any one of the preceding claims, wherein the remote module (20) includes an external communication stage (240), configured to emit signals containing at least one measured value.

5. Device (1) according to any one of the preceding claims, wherein the external piezoelectric transceiver (218) is configured to resonate at least one predetermined frequency and the internal piezoelectric transceiver (228) is configured to resonate at said at least one predetermined frequency.

6. Electric machine (300) for motor vehicle, said electric machine (300) comprising a stator (310), a rotor (320) and a device (1) according to any one of the preceding claims, said electric machine (300) being configured to be mounted in said vehicle in order to drive the wheels of said vehicle in rotation, electric machine (300) in which the main module (10) is mounted on the stator (310) and the remote module (20) is mounted on the rotor (320).

7. An electric machine (300) according to the preceding claim, wherein the rotor (320) comprises a shaft (321) having a first shaft portion (321A) and a second shaft portion (321B) mounted on the stator (310) by a bearing system (315), the first portion of shaft (321 A) having an end face (321A1) extending orthogonally to the longitudinal axis (X) of rotation of the rotor (320), the secondary winding (215) is mounted on said end face (321A1), the external piezoelectric transmitter-receiver (218) is mounted on the first portion of shaft (321A), the internal piezoelectric transmitter-receiver (228) and the sensing element (230) are mounted inside the rotor (320) and the primary winding (125) is mounted on a portion of the stator (310) facing said secondary winding (215).

8. Battery group (500) for motor vehicle, comprising a measuring device (1) according to any one of claims 1 to 5, the remote module (20) being mounted so that the sensing element (230) is placed respectively in at least one battery of the battery group (500).

9. Motor vehicle comprising a measuring device (1) according to any one of claims 1 to 5.

10. A method for measuring a parameter in a motor vehicle from a measuring device (1) according to any one of claims 1 to 5, said method comprising the steps of: - supplying (E1) the primary winding (125) by the control stage (110) with an alternating current, - generating (E2) by the primary winding (125) a magnetic field that varies according to said alternating current, - generating (E3) by the secondary winding (215) an alternating supply current (SCA) from the variations of the magnetic field generated by the primary winding (125), - transmitting (E4) said supply current (SCA) by the secondary winding (215) to the external piezoelectric transceiver (218), - emitting (E5), by the external piezoelectric transceiver (218), an ultrasonic supply signal (SU1), - receiving (E6),by the internal piezoelectric transceiver (228) of the emitted ultrasonic power signal (SU1), - power supply (E7) of the sensing element (230) by the internal piezoelectric transceiver (228) with an electric current generated from the received ultrasonic power signal (SU1) so that said sensing element (230) performs at least one measurement of the parameter, - measurement (E8) of the parameter by the sensitive element (230), - generation (E9) of a measurement signal (S) by the sensitive element (230), said measurement signal (S) comprising at least one value of the measured parameter, - transmission (E10), by the sensitive element (230), of the measurement signal (S) to the internal piezoelectric transceiver (228), - reception (E11), by the internal piezoelectric transceiver (228), of the measurement signal (S) generated by the sensitive element (230), - conversion (E12) of the received measurement signal (S) into an ultrasonic measurement signal (SU2), - emission (E13), by the internal piezoelectric transceiver (228), of said ultrasonic measurement signal (SU2), - reception (El4) by the external piezoelectric transceiver (218) of the emitted ultrasonic measurement signal (SU2), - conversion (El5) of the received ultrasonic measurement signal (SU2) into an alternating excitation current signal (SCE) containing at least one value of the measured parameter, - supplying (E16) of the secondary winding (215) by said excitation current signal (SCE), - generation (E17) of a magnetic field by the secondary winding (215) from said excitation current signal (SCE), - detection (E18), by the primary winding (125), of the variations of the magnetic field generated by the secondary winding (215), - determination (E19), by the control stage (110), of at least one parameter value measured from the variations of the magnetic field detected by the primary winding (125).

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