Piezoelectric measuring device for motor vehicle comprising resistance-sensitive element

Abstract

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

Description

[Technical Field] This invention relates to the automotive field, and more particularly to a piezoelectric measuring device with a resistance-sensitive element for motor vehicles and a method for implementing the piezoelectric measuring device. [Background Technology] As is known, an electric motor consists of a rotor and a stator. The operation of such a motor causes both the rotor and stator to heat up. However, elevated rotor temperature can lead to performance loss, and when a certain temperature is exceeded, it can cause the internal magnets to demagnetize, potentially damaging or even causing the motor to fail. Therefore, it is necessary to measure the internal temperature of the rotor in order to reduce its speed when the rotor temperature approaches its critical operating limits, thereby avoiding damage to the motor or preventing its failure.

[0001] Because the rotor rotates during its operation, it is difficult to directly measure the rotor temperature using wired temperature sensors, and therefore the rotor temperature is estimated via algorithms and models integrated into the motor's control system.

[0002] However, these integrated algorithms and models sometimes produce measurement errors of plus or minus 20°C, which is unsatisfactory in the context of controlling motors to avoid damage or failure.

[0003] Therefore, it would be advantageous to have a simple, reliable, and efficient solution that allows for at least partial overcoming of these shortcomings. [Summary of the Invention] Therefore, the subject of this invention is primarily a device for measuring parameters of a motor vehicle, the device comprising a main module and a remote module. The main module includes a control stage and a main piezoelectric transceiver configured to transmit ultrasonic power signals. The control stage is configured to power the main piezoelectric transceiver and command it to transmit ultrasonic power signals. The remote module includes a remote piezoelectric transceiver and a resistance-sensitive element connected to a terminal of the remote piezoelectric transceiver. The remote piezoelectric transceiver is configured to receive the ultrasonic power signals transmitted by the main piezoelectric transceiver and use the ultrasonic waves... A power signal supplies power to the sensitive element, which is configured to, when powered, measure the parameter and generate a measurement signal with an amplitude proportional to the measured value, and transmit the measurement signal to the remote piezoelectric transceiver, which is configured to: receive the measurement signal generated by the sensitive element to generate an ultrasonic measurement signal, the ultrasonic measurement signal being a reflection of the measurement signal and proportional to the value of the measured parameter; and transmit the ultrasonic measurement signal to the main piezoelectric transceiver, the control stage being configured to determine the value of the parameter based on the ultrasonic measurement signal received by the main piezoelectric transceiver.

[0004] The device according to the invention allows for remote measurement via a remote module by powering a sensitive measuring element with energy from a signal transmitted by the main module via a wireless link. Therefore, measurements can be performed as close as possible to the magnet, which improves the control performance of the electric machine. The invention further eliminates the need for metal barriers, such as housings and protective flanges, which may at least partially block electromagnetic waves, such as those used for Wi-Fi or Bluetooth.

[0005] In one embodiment, the primary piezoelectric transceiver and the remote piezoelectric transceiver are configured to resonate at at least one given predetermined frequency. The control stage is configured to generate a signal at the at least one predetermined frequency and transmit the generated signal to the primary piezoelectric transceiver, and the measurement stage is configured to generate a signal at the at least one predetermined frequency and transmit the generated signal to the remote piezoelectric transceiver. This resonance allows for optimization of the ultrasonic signal transmission rate and current consumption.

[0006] Preferably, the remote piezoelectric transceiver is configured to resonate at two predetermined frequencies of approximately 200 kHz and 2 MHz.

[0007] Advantageously, the control level includes a memory region storing a lookup table that is predetermined, for example empirically determined, and contains a correspondence between the amplitude of the ultrasonic measurement signal and the range of values ​​for the parameter.

[0008] The present invention also relates to an electric motor for a motor vehicle, the electric motor comprising a stator, a rotor and a measuring device as described above, the electric motor being configured to be mounted in the vehicle to drive the wheels of the vehicle to rotate, wherein the main module is mounted on the stator and the remote module is mounted on the rotor.

[0009] Advantageously, the remote module is installed inside the rotor.

[0010] In one embodiment, the rotor includes a shaft comprising a first shaft portion and a second shaft portion mounted on the stator via a bearing system. The first shaft portion has an end face extending orthogonally to the longitudinal axis of rotation of the rotor. The remote piezoelectric transceiver is mounted on the end face, and the main piezoelectric transceiver is mounted on the portion of the stator facing the remote piezoelectric transceiver.

[0011] The present invention also relates to a motor vehicle battery including the measuring device as described above, wherein a remote module is mounted such that a sensitive element is placed inside the battery.

[0012] The present invention also relates to a motor vehicle battery pack including the measuring device as described above, the measuring device including at least one remote module, the at least one remote module being mounted such that a sensitive element is placed inside at least one cell of the battery pack.

[0013] The present invention also relates to a fuel cell for a motor vehicle, the fuel cell including the measuring device as described above, wherein a remote module is mounted such that a sensitive element is placed inside the fuel cell.

[0014] The present invention also relates to a motor vehicle that includes the measuring device described above.

[0015] In one embodiment, the vehicle is an electric vehicle or a hybrid electric vehicle, and includes the electric motor described above.

[0016] In one embodiment, the vehicle includes a battery or battery pack or fuel cell as described above.

[0017] The present invention also relates to a method for measuring parameters in a motor vehicle using the measuring device described above, the method comprising the following steps: - The control level commands the main piezoelectric transceiver to transmit an ultrasonic power signal. The ultrasonic power signal is transmitted by the main piezoelectric transceiver. - The transmitted ultrasonic power signal is received by the remote piezoelectric transceiver. The remote piezoelectric transceiver uses the ultrasonic power signal to power the sensitive element. - This parameter is measured by the sensitive element. - A measurement signal is generated by this sensing element, the amplitude of which is proportional to the value of the measured parameter. - The generated measurement signal is transmitted by the sensitive element to the remote piezoelectric transceiver. - An ultrasonic measurement signal is generated by the remote piezoelectric transceiver. This ultrasonic measurement signal is a reflection of the measured signal, and the amplitude of the ultrasonic measurement signal is proportional to the value of the measured parameter. - The ultrasonic measurement signal is transmitted to the main piezoelectric transceiver. The ultrasonic measurement signal is received by the main piezoelectric transceiver. The value of this parameter is determined by the control stage based on the ultrasonic measurement signal received by the main piezoelectric transceiver. [Image Description] Other features and advantages of the invention will become more apparent upon reading the following description. This description is purely illustrative and should be read with reference to the accompanying drawings, in which: [Figure 1 ] Figure 1 An embodiment of the measuring device according to the present invention is illustrated schematically in a functional manner.

[0018] [ Figure 2 ] Figure 2 An example of an electric machine according to the present invention is shown schematically.

[0019] [ Figure 3 ] Figure 3 An example of a battery according to the present invention is shown schematically.

[0020] [ Figure 4 ] Figure 4 An example of a battery pack according to the present invention is shown schematically.

[0021] [ Figure 5 ] Figure 5 An example of a fuel cell according to the present invention is illustrated schematically.

[0022] [ Figure 6 ] Figure 6 An embodiment of the method according to the present invention is illustrated schematically.

[0023] [ Figure 7 ] Figure 7 The simulation obtained using the device according to the invention is illustrated schematically. [Detailed Implementation] Figure 1 This is an example of a measuring device 1 according to the present invention. Device 1 is intended to be installed in a motor vehicle.

[0024] Device 1 includes a main module 10 and a remote module 20.

[0025] Main Module 10 The main module 10 includes a control stage 110 and a main piezoelectric transceiver 120.

[0026] The control stage 110 is configured to power the piezoelectric transceiver and command the piezoelectric transceiver to transmit an ultrasonic signal, preferably at the resonant frequency of the main piezoelectric transceiver 120.

[0027] The main piezoelectric transceiver 120 is configured to transmit and receive ultrasonic signals known as the “power” signal SUA, with the purpose of powering the remote module 20.

[0028] Preferably, the main piezoelectric transceiver 120 is configured to resonate at at least one predetermined frequency, and preferably at two predetermined frequencies (e.g., 200 kHz and 2 MHz).

[0029] Remote Module 20 The remote module 20 includes a remote piezoelectric transceiver 210 and a resistance-sensitive element 230 connected to the terminals of the remote piezoelectric transceiver 210.

[0030] The remote piezoelectric transceiver 210 is configured to receive the ultrasonic power signal SUA emitted by the main piezoelectric transceiver 120.

[0031] Preferably, the remote piezoelectric transceiver 210 is configured to resonate at at least one predetermined frequency, and preferably at two predetermined frequencies (e.g., 200 kHz and 2 MHz).

[0032] The remote piezoelectric transceiver 210 is configured to receive an ultrasonic power signal SUA emitted by the main piezoelectric transceiver 120 and to use the ultrasonic power signal SUA to power the sensitive element 230.

[0033] The sensing element 230 is configured to measure parameters, generate a measurement signal S with an amplitude proportional to the measured value, and transmit the measurement signal S to the remote piezoelectric transceiver 210 when it is powered by the remote piezoelectric transceiver 210.

[0034] The parameters measured can be, for example, air temperature, air pressure, moisture content, current, mechanical force (stress), torque, etc.

[0035] It should be noted that the remote module 20 may include more than one sensing element in order to measure multiple different parameters and / or multiple identical parameters at different locations.

[0036] The remote piezoelectric transceiver 210 is configured to receive a measurement signal S generated by the sensing element 230 in order to generate an ultrasonic measurement signal SUM, which is a reflection of the measurement signal S and proportional to the value of the measured parameter. When the remote piezoelectric transceiver 210 is powered by the measurement signal S, the ultrasonic measurement signal generated by the remote piezoelectric transceiver 210 takes the form of an echo.

[0037] The remote piezoelectric transceiver 210 is configured to transmit the ultrasonic measurement signal SUM to the main piezoelectric transceiver 120.

[0038] The main piezoelectric transceiver 120 is configured to receive the ultrasonic measurement signal SUM and transmit it to the control stage 110.

[0039] The control stage 110 is configured to determine the value of the parameter based on the ultrasonic measurement signal SUM received by the main piezoelectric transceiver 120.

[0040] The measured value can be determined, for example, based on the amplitude of the ultrasonic measurement signal using a lookup table stored in the memory area of ​​control level 110. Such a table may be determined empirically in advance.

[0041] Example of use of the measuring device according to the present invention Example 1: Electric Machine 300 Figure 2 An example of an electric motor 300 for a motor vehicle is shown. The electric motor 300 is configured to be installed in the vehicle to drive the wheels of the vehicle to rotate.

[0042] The electric machine 300 includes a stator 310, a rotor 320, and the device 1 as described above.

[0043] The main module 10 is mounted on the stator 310, and the remote module 20 is mounted on the rotor 320.

[0044] The rotor 320 is configured to rotate about the longitudinal axis X.

[0045] In this example, the rotor 320 includes an integral shaft 321 that extends along the rotational longitudinal axis X and includes a first shaft portion 321A and a second shaft portion 321B that are connected to the stator 310 via a bearing system 315.

[0046] The first shaft portion 321A includes an end face 321A1 extending orthogonally to the longitudinal axis of rotation X of the rotor 320. A remote piezoelectric transceiver 210 is mounted on the end face 321A1, and a main piezoelectric transceiver 120 is mounted on the portion of the stator 310 facing the remote piezoelectric transceiver 21.

[0047] Example 2: Battery 400 Figure 3 This is an example of a battery 400 used in motor vehicles.

[0048] The main module 10 is placed away from the battery 400, while the remote module 20 is installed on the battery 400, so that the sensing element 230 measures parameters inside the battery 400, such as temperature or pressure, moisture content, current, mechanical force (stress), torque, etc.

[0049] It should be noted that the remote piezoelectric transceiver 210 and the measuring stage 220 can be mounted on the external surface of the battery 400, or mounted inside the battery 400 together with the sensing element 230, as in Example 1 of the electric machine.

[0050] Example 3: Battery pack 500 Figure 4 This is an example of a battery pack 500 used in motor vehicles.

[0051] The main module 10 is placed away from the battery pack 500, while one or more corresponding remote modules 20 are mounted on one or more batteries 400 of the battery pack 500, such that the sensing element 230 of each remote module 20 measures parameters inside each battery 400, such as temperature or pressure.

[0052] Example 4: Fuel Cell 600 Figure 5 This is an example of a fuel cell 600 used in motor vehicles.

[0053] The main module 10 is placed away from the fuel cell 600, while the remote module 20 is mounted on the fuel cell 600, allowing the sensing element 230 to measure parameters inside the fuel cell 600, such as in the circuit used to supply air to the membrane of the fuel cell 600. Again, the measured parameters may be, for example, temperature, pressure, moisture content, current, mechanical force (stress), and / or torque.

[0054] Examples of implementation methods Now refer to Figure 6 An example of an implementation of device 1 is described. In this non-limiting example, the parameter to be measured may be, for example, temperature, particularly the temperature inside the rotor 320 of the electric machine 300.

[0055] First, when parameters need to be measured, in step E1, the control level 110 of the main module 10 commands the main piezoelectric transceiver 120 to transmit an ultrasonic power signal SUA, preferably at one of the resonant frequencies, to improve the transmission quality of the ultrasonic power signal SUA.

[0056] In step E2, the main piezoelectric transceiver 120 transmits an ultrasonic power signal SUA, which is received by the remote piezoelectric transceiver 210 in step E3.

[0057] In step E4, the remote piezoelectric transceiver 210 supplies power to the sensitive element 230 using the ultrasonic power signal SUA.

[0058] Once powered, the sensing element 230 measures the parameter of interest in step E5, which may be, for example, air temperature, air pressure, moisture content, current, mechanical force (stress), or torque.

[0059] During parameter measurement, the sensing element 230 generates a measurement signal S in step E6. The amplitude of the measurement signal varies with the value of the measured parameter, and the resistance of the sensing element 230 varies with the parameter (e.g., temperature).

[0060] In step E7, the generated measurement signal S is transmitted to a remote piezoelectric transceiver 210. In step E8, the remote piezoelectric transceiver generates an ultrasonic measurement signal SUM in response to receiving the measurement signal S. This ultrasonic measurement signal is a mirror image of the measurement signal S, meaning its amplitude is proportional to the measured value. "Mirror image" means the signal is the same or proportional, i.e., its amplitude may be larger or smaller, but varies proportionally to the amplitude of the measured signal S.

[0061] In step E9, the remote piezoelectric transceiver 210 transmits the ultrasonic measurement signal SUM to the main piezoelectric transceiver 120, which receives the ultrasonic measurement signal in step E10 and transmits it to the control stage 110.

[0062] Then, in step E11, the control level 110, for example, uses a predetermined lookup table stored in its memory area to determine the value of the parameter based on the ultrasonic measurement signal SUM received by the main piezoelectric transceiver 120.

[0063] simulation Figure 7 An example of a simulation performed using the device 1 according to the invention is shown.

[0064] The ultrasonic power signal SUA emitted by the main piezoelectric transceiver 120 has a substantially sinusoidal shape.

[0065] In response to the excitation (or as an echo of) the ultrasonic power signal SUA, the remote piezoelectric transceiver 210 generates and transmits an ultrasonic measurement signal SUM-E, which reaches an amplitude A after stabilizing during the second oscillation. This amplitude A is proportional to the temperature value measured by the resistive sensing element 230, and more precisely, to the resistance of the sensing element 230 (which varies with temperature). The ultrasonic measurement signal SUM-R received by the main piezoelectric transceiver 120 has an increasing-then-decreasing sinusoidal shape, and therefore the maximum amplitude corresponds to amplitude A, and thus to the measured temperature value.

[0066] Therefore, the present invention enables the use of a wirelessly powered remote module to measure parameters, thereby avoiding the use of replaceable batteries, which is particularly advantageous in the case of the rotor of an electric machine.

Claims

1. An apparatus (1) for measuring parameters of a motor vehicle, the apparatus (1) comprising a main module (10) and a remote module (20), the main module (10) comprising a control stage (110) and a main piezoelectric transceiver (120) configured to transmit an ultrasonic power signal (SUA), the control stage (110) being configured to power the main piezoelectric transceiver (120) and command the main piezoelectric transceiver (120) to transmit the ultrasonic power signal (SUA), the remote module (20) comprising a remote piezoelectric transceiver (210) and a resistance-sensitive element (230) connected to a terminal of the remote piezoelectric transceiver (210), the remote piezoelectric transceiver (210) being configured to receive the ultrasonic power signal (SUA) transmitted by the main piezoelectric transceiver (120) and use the ultrasonic power signal (SUA) transmitted by the main piezoelectric transceiver (120) for measurement. An acoustic power signal (SUA) powers the sensing element (230), which is configured to, when powered, measure the parameter and generate a measurement signal (S) with an amplitude proportional to the measured value, and transmit the measurement signal (S) to the remote piezoelectric transceiver (210), which is configured to: receive the measurement signal (S) generated by the sensing element (230) to generate an ultrasonic measurement signal (SUM), which is a reflection of the measurement signal (S) and proportional to the value of the measured parameter; and transmit the ultrasonic measurement signal (SUM) to the main piezoelectric transceiver (120), the control stage (110) being configured to determine the value of the parameter based on the ultrasonic measurement signal (SUM) received by the main piezoelectric transceiver (120).

2. The device (1) as claimed in claim 1, wherein, The main piezoelectric transceiver (120) and the remote piezoelectric transceiver (210) are configured to resonate at at least one given predetermined frequency, the control stage (110) is configured to generate a signal at the at least one predetermined frequency and transmit the generated signal to the main piezoelectric transceiver (120), and the measurement stage (220) is configured to generate a signal at the at least one predetermined frequency and transmit the generated signal to the remote piezoelectric transceiver (210).

3. The device (1) as claimed in claim 2, wherein, The remote piezoelectric transceiver (210) is configured to resonate at two predetermined frequencies of approximately 200 kHz and 2 MHz.

4. The device (1) as described in any of the preceding claims, wherein, The control level (110) includes a memory area storing a lookup table that is predetermined, for example empirically determined, and contains a correspondence between the amplitude of the ultrasonic measurement signal (SUM) and the range of values ​​for the parameter.

5. An electric motor (300) for a motor vehicle, the electric motor (300) comprising a stator (310), a rotor (320) and a device (1) as described in any of the preceding claims, the electric motor (300) being configured to be mounted in the vehicle to drive the wheels of the vehicle to rotate, wherein the main module (10) is mounted on the stator (310) and the remote module (20) is mounted on the rotor (320).

6. The electric machine (300) as claimed in the preceding claim, wherein, The remote module (20) is installed inside the rotor (320).

7. The electric machine (300) as claimed in any one of claims 5 and 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) via a bearing system (315). The first shaft portion (321A) has an end face (321A1) extending orthogonally to the longitudinal axis of rotation (X) of the rotor (320). The remote piezoelectric transceiver (210) is mounted on the end face (321A1), and the main piezoelectric transceiver (120) is mounted on the portion of the stator (310) facing the remote piezoelectric transceiver (210).

8. A motor vehicle battery (400) or battery pack (500) or fuel cell (600) comprising a measuring device (1) as claimed in any one of claims 1 to 4, wherein the remote module (20) is mounted such that the sensing element (230) is respectively placed inside the battery (400), or inside at least one battery of the battery pack (500), or inside the fuel cell (600).

9. A motor vehicle comprising the measuring device (1) as claimed in any one of claims 1 to 4.

10. A method for measuring parameters in a motor vehicle using the measuring device (1) as described in any one of claims 1 to 4, the method comprising the steps of: - The control level (110) commands (E1) to transmit an ultrasonic power signal (SUA) from the main piezoelectric transceiver (120). - The ultrasonic power signal (SUA) is transmitted (E2) by the main piezoelectric transceiver (120). - The ultrasonic power signal (SUA) transmitted by the remote piezoelectric transceiver (210) (E3) is received. - The remote piezoelectric transceiver (210) uses the ultrasonic power signal (SUA) to power the sensitive element (230) (E4). - This parameter is measured (E5) by the sensitive element (230). - A measurement signal (S) is generated by the sensing element (230), the amplitude of which is proportional to the value of the measured parameter. - The generated measurement signal (S) is transmitted (E7) by the sensitive element (230) to the remote piezoelectric transceiver (210). - An ultrasonic measurement signal (SUM) is generated by the remote piezoelectric transceiver (210), which is a reflection of the measurement signal (S), and the amplitude of the ultrasonic measurement signal is proportional to the value of the measured parameter. - Transmit the ultrasonic measurement signal (SUM) (E9) to the main piezoelectric transceiver (120). - The ultrasonic measurement signal (SUM) is received (E10) by the main piezoelectric transceiver (120). - The value of the parameter is determined by the control stage (110) based on the ultrasonic measurement signal (SUM) received by the main piezoelectric transceiver (120).

Images