Piezoelectric measuring device with resistive sensing element for automotive vehicles

Abstract

The invention relates to a device (1) for measuring a parameter for a motor vehicle, comprising a main module (10) and a remote module (20) comprising a sensing element (230) configured to measure the parameter and a remote piezoelectric transceiver (210) configured to generate an ultrasonic measurement signal, image of the measurement signal (S) and proportional to the values ​​of the measured parameter, and to send it to the main module (10). Figure 1

Description

Title of the invention: Piezoelectric measuring device with resistive sensing element for motor vehicles technical field

[0001] The present invention relates to the automotive field and more particularly concerns a piezoelectric measuring device with a resistive sensitive element for a motor vehicle 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 main piezoelectric transceiver configured to emit a power ultrasonic signal, said control stage being configured to electrically power said main piezoelectric transceiver and to control the emission of a power ultrasonic signal by said main piezoelectric transceiver, said remote module comprising a remote piezoelectric transceiver and a resistive sensing element connected to the terminals of said remote piezoelectric transceiver, said remote piezoelectric transceiver being configured to receive the power ultrasonic signal emitted by the piezoelectric transceiver main and to electrically power the sensing element from said ultrasonic power signal, the sensing element being configured to, when electrically powered, measure the parameter and generate a measurement signal whose amplitude is proportional to the measured value and said measurement signal to the remote piezoelectric transceiver, said remote piezoelectric transceiver being configured to receive the measurement signal generated by the sensing element, to generate an ultrasonic measurement signal, image of the measurement signal and proportional to the value of the measured parameter, and to transmit said ultrasonic measurement signal to the main piezoelectric transceiver, the control stage being configured to determine the value of the parameter from the ultrasonic measurement signal received by the main piezoelectric transceiver.

[0007] The device according to the invention allows for remote measurements to be taken 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, thereby increasing the performance of the electrical machine control. The invention also eliminates the need for metallic barriers such as, for example, the casing and protective flanges, which can at least partially block electromagnetic waves such as Wi-Fi or Bluetooth.

[0008] In one embodiment, the main piezoelectric transceiver and the remote piezoelectric transceiver are configured to resonate at least one predetermined frequency. The control stage is configured to generate a signal at said predetermined frequency and to supply the generated signal to the main piezoelectric transceiver, and the measurement stage is configured to generate a signal at said predetermined frequency and to supply the generated signal to the remote piezoelectric transceiver. Such resonance optimizes the ultrasonic signal transmission rate and the electrical current consumption.

[0009] Preferably, the remote piezoelectric transceiver is configured to resonate at two predetermined frequencies, on the order of 200 kHz and 2 MHz.

[0010] Advantageously, the control stage includes a memory area in which is stored a predetermined table, for example empirically, comprising the correspondence between the amplitude of the ultrasonic measurement signal and a range of parameter values.

[0011] 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 described 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.

[0012] Advantageously, the remote module is mounted inside the rotor.

[0013] In one embodiment, 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 remote piezoelectric transmitter-receiver is mounted on said end face and the main piezoelectric transmitter-receiver is mounted on a portion of the stator facing said remote piezoelectric transmitter-receiver.

[0014] 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 inside said battery.

[0015] 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 inside at least one of the batteries in the battery group.

[0016] 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 inside said fuel cell.

[0017] The invention also relates to a motor vehicle comprising a measuring device as previously described.

[0018] In one embodiment, the vehicle is an electric or hybrid electric vehicle and includes an electric machine as described above.

[0019] In one embodiment, the vehicle includes a battery or a group of batteries or a fuel cell as described above.

[0020] 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:

[0021] - control, by the control stage, of the emission of an ultrasonic signal powered by the main piezoelectric transceiver,

[0022] - emission, by the main piezoelectric transceiver, of said ultrasonic signal food,

[0023] - reception, by the remote piezoelectric transceiver, of the ultrasonic signal power supply emitted,

[0024] - power supply, via the remote piezoelectric transceiver, from the ultrasonic power supply signal, from the sensitive element,

[0025] - measurement, by the sensitive element, of the parameter,

[0026] - generation, by the sensitive element, of a measurement signal whose amplitude is proportional to the value of the measured parameter,

[0027] - transmission, by the sensitive element, of said measurement signal generated at the transmitter- remote piezoelectric receiver,

[0028] - generation, by the remote piezoelectric transceiver, of an ultrasonic signal of measurement, image of the measurement signal, and whose amplitude is proportional to the value of the measured parameter,

[0029] - emission of said ultrasonic measurement signal to the transceiver main piezoelectric,

[0030] - reception, by the main piezoelectric transceiver, of the ultrasonic signal of measure,

[0031] - determination, by the control stage, of the parameter value from the signal measurement ultrasound received by the main piezoelectric transceiver. Brief description of the drawings

[0032] 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:

[0033] [Fig-1] Fig. 1 schematically and functionally illustrates a form of realization of the measuring device according to the invention.

[0034] [Fig.2] Fig.2 schematically illustrates an example of an electrical machine according to the invention.

[0035] [Fig.3] Fig.3 schematically illustrates an example of a battery according to the invention.

[0036] [Fig.4] Fig.4 schematically illustrates an example of a battery group according to the invention.

[0037] [Fig.5] Fig.5 schematically illustrates an example of a fuel cell according to the invention.

[0038] [Fig.6] Fig.6 schematically illustrates one embodiment of the process according to the invention.

[0039] [Fig.7] Fig.7 schematically illustrates a simulation obtained with the device according to the invention. Description of the implementation methods

[0040] 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.

[0041] Device 1 comprises a main module 10 and a remote module 20.

[0042] Main Module 10

[0043] The main module 10 includes a control stage 110 and a main piezoelectric transceiver 120.

[0044] The control stage 110 is configured to electrically supply said piezoelectric transmitter and to control the emission of ultrasonic signals by said piezoelectric transmitter, preferably at a resonant frequency of said and main piezoelectric transmitter-receiver 120.

[0045] The main piezoelectric transceiver 120 is configured to emit and receive ultrasonic signals, referred to as "power" signals SUA, to electrically power the remote module 20.

[0046] Preferably, the main piezoelectric transceiver 120 is configured to resonate at least one predetermined frequency, preferably at two predetermined frequencies, for example 200 kHz and 2 MHz.

[0047] Remote Module 20

[0048] The remote module 20 includes a remote piezoelectric transceiver 210 and a resistive sensitive element 230 connected to the terminals of said remote piezoelectric transceiver 210.

[0049] The remote piezoelectric transceiver 210 is configured to receive SUA power supply ultrasonic signals emitted by the main piezoelectric transceiver 120.

[0050] Preferably, the remote piezoelectric transceiver 210 is configured to resonate at least one predetermined frequency, preferably at two predetermined frequencies, for example 200 kHz and 2 MHz.

[0051] The remote piezoelectric transceiver 210 is configured to receive the ultrasonic power signal SUA emitted by the main piezoelectric transceiver 120 and to electrically power the sensing element 230 from said ultrasonic power signal SUA.

[0052] The sensitive element 230 is configured to, when electrically powered by the remote piezoelectric transceiver 210, measure the parameter, generate a measurement signal S whose amplitude is proportional to the measured value and provide said measurement signal S to the remote piezoelectric transceiver 210.

[0053] The measured parameter can, for example, be the air temperature, the air pressure, the humidity level, the intensity of an electric current, a mechanical force (stress), a torque, etc.

[0054] It should be noted that the remote module 20 can include more than one sensitive element to measure several different parameters and / or several identical parameters at different locations.

[0055] The remote piezoelectric transceiver 210 is configured to receive the measurement signal S generated by the sensitive element 230 to generate an ultrasonic signal The measurement signal SUM is an image of the measurement signal S and is proportional to the value of the measured parameter. The ultrasonic measurement signal is generated by the remote piezoelectric transceiver 210 as an echo when said remote piezoelectric transceiver 210 is electrically powered by the measurement signal S.

[0056] The remote piezoelectric transceiver 210 is configured to emit said ultrasonic measurement signal SUM to the main piezoelectric transceiver 120.

[0057] The main piezoelectric transceiver 120 is configured to receive the ultrasonic measurement signal SUM and transmit it to the control stage 110.

[0058] The control stage 110 is configured to determine the parameter value from the ultrasonic measurement signal SUM received by the main piezoelectric transceiver 120.

[0059] The measured value can for example be determined from the amplitude of the ultrasonic measurement signal using a lookup table stored in a memory area of ​​the controlled stage 110. Such a table may have been determined beforehand empirically.

[0060] Examples of use of the measuring device according to the invention

[0061] Example 1: 300 electric machine

[0062] The [Fig.2] is an example of an electric machine 300 for a motor vehicle. The 300 electric machine is configured to be mounted in the vehicle in order to drive the wheels of said vehicle in rotation.

[0063] The electric machine 300 comprises a stator 310, a rotor 320 and a device 1 as previously presented.

[0064] The main module 10 is mounted on the stator 310 and the remote module 20 is mounted on the rotor 320.

[0065] The rotor 320 is configured to rotate around a longitudinal axis X.

[0066] 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.

[0067] The first portion of the shaft 321A comprises an end face 321A1 extending orthogonally to the longitudinal axis X of rotation of the rotor 320. The remote piezoelectric transceiver 210 is mounted on said end face 321A1 and the main piezoelectric transceiver 120 is mounted on a portion of the stator 310 facing said remote piezoelectric transceiver 21.

[0068] Example 2: 400 battery

[0069] The [Fig.3] is an example of a 400 battery for a motor vehicle.

[0070] The main module 10 is placed at a distance from the battery 400 while the remote module 20 is mounted at the level of the battery 400 so that the sensitive element 230 measures a parameter inside said battery 400, for example temperature or pressure, humidity level, intensity of an electric current, mechanical force (stress), torque, or other.

[0071] It should be noted that the remote piezoelectric transceiver 210 and the measuring stage 220 can be mounted on an external face of the battery 400 or inside the battery 400 with the sensitive element 230, as in Example 1 of an electric machine.

[0072] Example 3: 500 battery group

[0073] The [Fig.4] is an example of a 500 battery group for a motor vehicle.

[0074] The main module 10 is placed at a distance from the battery group 500 while one or more remote modules 20 are mounted respectively at 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, for example temperature or pressure or other.

[0075] Example 4: 600 fuel cell

[0076] The [Fig.5] is an example of a 600 fuel cell for a motor vehicle.

[0077] The main module 10 is placed at a distance from the fuel cell 600 while The remote module 20 is mounted at the level of the fuel cell 600 so that the sensitive element 230 measures a parameter inside said fuel cell 600, for example at the level of the air supply circuit of the membranes of the fuel cell 600. Here again, the parameter(s) measured can for example be temperature, pressure, humidity level, intensity of an electric current, a mechanical force (stress) or a torque.

[0078] Example of implementation

[0079] An example of the implementation of device 1 will now be described with reference to [Fig. 6]. 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.

[0080] First, when it is necessary to measure the parameter, the control stage 110 of the main module 10, commands in a step El1, the emission of an ultrasonic power signal SUA by the main piezoelectric transceiver 120, preferably at one of the resonant frequencies to improve the transmission quality of said ultrasonic power signal SUA.

[0081] In a step E2, the main piezoelectric transceiver 120 emits the SUA power supply ultrasonic signal which is received by the remote piezoelectric transceiver 210 in a step E3.

[0082] In a step E4, the remote piezoelectric transceiver 210 electrically supplies the sensitive element 230 with the ultrasonic power supply signal SUA.

[0083] Once electrically powered, the sensitive element 230 measures in a step E5 the parameter of interest, which can for example be the air temperature, the air pressure, the humidity level, the intensity of an electric current, a mechanical force (stress) or a torque.

[0084] During the measurement of the parameter, the sensitive element 230 generates, in a step E6, a measurement signal S whose amplitude varies with the value of the measured parameter, the resistance of the sensitive element 230 varying with the parameter, for example the temperature.

[0085] The generated measurement signal S is transmitted in a step E7 to the remote piezoelectric transceiver 210, which, in a step E8, generates, in response to the reception of the measurement signal S, an ultrasonic measurement signal SUM that is the image of the measurement signal S, i.e., whose amplitude is proportional to the measured value. By "image," it is understood that the signal is identical or proportional, i.e., of a greater or lesser amplitude, but which varies proportionally to the amplitude of the measurement signal S.

[0086] The ultrasonic measurement signal SUM is emitted in a step E9 by the remote piezoelectric transceiver 210 to the main piezoelectric transceiver 120 which receives it and transmits it to the control stage 110 in a step E10.

[0087] The control stage 110 then determines in a step El 1 the value of the parameter from the ultrasonic measurement signal SUM received by the main piezoelectric transceiver 120, for example from the predetermined lookup table stored in its memory area.

[0088] Simulation

[0089] Figure 7 illustrates an example of a simulation carried out with device 1 according to the invention.

[0090] The ultrasonic power supply signal SUA emitted by the main piezoelectric transceiver 120 has a substantially sinusoidal shape.

[0091] In response (or echo) to the excitation by said ultrasonic power supply signal SUA, the remote piezoelectric transceiver 210 generates an ultrasonic measurement signal SUM-E which will reach an amplitude A once stabilized at the second oscillation, this amplitude A being proportional to the temperature value measured by the resistive sensing element 230, more precisely to the resistance of said sensing element 230, which varies with temperature. The ultrasonic measurement signal SUM-R which is received by the main piezoelectric transceiver 120 has a shape sinusoidal increasing then decreasing, therefore the maximum amplitude corresponds to the amplitude value A and therefore to the measured temperature value.

[0092] The invention therefore makes it possible to measure a parameter using a remote module 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

Demands

1. 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 main piezoelectric transceiver (120) configured to emit a power ultrasonic signal (PUS), said control stage (110) being configured to electrically power said main piezoelectric transceiver (120) and to control the emission of a power ultrasonic signal (PUS) by said main piezoelectric transceiver (120), said remote module (20) comprising a remote piezoelectric transceiver (210) and a resistive sensing element (230) connected to the terminals of said remote piezoelectric transceiver (210),The remote piezoelectric transceiver (210) is configured to receive the ultrasonic power signal (UPS) emitted by the main piezoelectric transceiver (120) and to electrically power the sensing element (230) from said ultrasonic power signal (UPS). The sensing element (230) is configured, when electrically powered, to measure the parameter and generate a measurement signal (S) whose amplitude is proportional to the measured value. The measurement signal (S) is transmitted to the remote piezoelectric transceiver (210). The remote piezoelectric transceiver (210) is configured to receive the measurement signal (S) generated by the sensing element (230), to generate an ultrasonic measurement signal (UMS), which is an image of the measurement signal (S) and proportional to the value of the measured parameter, and to transmit said ultrasonic measurement signal (UMS) to the main piezoelectric transceiver. (120),the control stage (110) being configured to determine the parameter value from the ultrasonic measurement signal (SUM) received by the main piezoelectric transceiver (120).

2. Device (1) according to claim 1, wherein, the main piezoelectric transceiver (120) and the remote piezoelectric transceiver (210) being configured to resonate at least one of the same predetermined frequencies, the control stage (110) is configured to generate a signal at said at least one predetermined frequency and to provide the generated signal to the transceiver main piezoelectric receiver (120) and measurement stage (220) is configured to generate a signal at said at least one predetermined frequency and to provide the generated signal to the remote piezoelectric transceiver (210).

3. Device (1) according to claim 2, wherein the remote piezoelectric transceiver 210 is configured to resonate at two predetermined frequencies, of the order of 200 kHz and 2 MHz.

4. Device (1) according to any one of the preceding claims, wherein the control stage (110) includes a memory area in which is stored a predetermined table, for example empirically, comprising the correspondence between the amplitude of the measurement ultrasonic signal (SUM) and a range of parameter values.

5. 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).

6. Electric machine (300) according to the preceding claim, wherein the remote module (20) is mounted inside the rotor (320).

7. Electric machine (300) according to any one of claims 5 or 6, wherein the rotor (320) includes a shaft (321) comprising a first shaft portion (321A) and a second shaft portion (321B) mounted on the stator (310) by a bearing system (315), the first shaft portion (321A) having an end face (321A1) extending orthogonally to the longitudinal axis (X) of rotation of the rotor (320), the remote piezoelectric transmitter-receiver (210) is mounted on said end face (321A1) and the main piezoelectric transmitter-receiver (120) is mounted on a portion of the stator (310) facing said remote piezoelectric transmitter-receiver (210).

8. A battery (400) or battery bank (500) or fuel cell (600) for a motor vehicle, comprising a measuring device (1) according to any one of claims 1 to 4, the remote module (20) being mounted so that the sensing element (230) is placed respectively inside said battery (400), or inside at least one battery of the battery group (500) or inside the fuel cell (600).

9. Motor vehicle comprising a measuring device (1) according to any one of claims 1 to 4.

10. A method for measuring a parameter in a motor vehicle using a measuring device (1) according to any one of claims 1 to 4, said method comprising the steps of: - control (E1), by the control stage (110), of the emission of a power ultrasonic signal (SUA) by the main piezoelectric transceiver (120), - emission (E2), by the main piezoelectric transceiver (120), of said power ultrasonic signal (SUA), - reception (E3), by the remote piezoelectric transceiver (210), of the emitted power ultrasonic signal (SUA), - power supply (E4), by the remote piezoelectric transceiver (210), from the power ultrasonic signal (SUA), to the sensing element (230), - measurement (E5), by the sensing element (230), of the parameter, - generation (E6), by the element sensitive (230), of a measurement signal (S) whose amplitude is proportional to the value of the measured parameter, - transmission (E7),by the sensitive element (230), of said measurement signal (S) generated at the remote piezoelectric transceiver (210), - generation (E8), by the remote piezoelectric transceiver (210), of an ultrasonic measurement signal (SUM), image of the measurement signal (S) and whose amplitude is proportional to the value of the measured parameter, - transmission (E9) of said ultrasonic measurement signal (SUM) to the main piezoelectric transceiver (120), - reception (E10), by the main piezoelectric transceiver (120), of the ultrasonic measurement signal (SUM), - determination (E11), by the control stage (110), of the value of the parameter from the ultrasonic measurement signal (SUM) received by the main piezoelectric transceiver (120).

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