Piezoelectric measuring device for motor vehicle

Abstract

The invention relates to a device (1) for measuring a parameter, comprising a main module (10) and a remote module (20), said main module (10) comprising a control stage (110) and a piezoelectric transmitter (120) configured to transmit an ultrasonic signal, said control stage (110) being configured to power said piezoelectric transmitter (120) and to command the transmission of a signal by said piezoelectric transmitter (110), the remote module (20) comprises: a piezoelectric receiver (210); the system comprises a piezoelectric receiver (210) configured to receive a parameter, a sensitive element (230) configured to measure the parameter and generate a measurement signal, and a measurement stage (220) configured to collect and store energy of the signal received by the piezoelectric receiver (210) in order to power the sensitive element (230), receive the measurement signal generated by the sensitive element (230), and generate a measurement signal from the piezoelectric receiver (210). A value of the measured parameter is extracted from the received measurement signal and a signal containing the extracted value of the parameter is commanded to be transmitted.

Description

Technical Field

[0001] This invention relates to the automotive field, and more particularly to a piezoelectric measuring device for motor vehicles and a method for implementing the piezoelectric measuring device. Background Technology

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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

[0006] Therefore, the first subject of the present invention is an apparatus for measuring parameters in a motor vehicle, the apparatus comprising a main module and a remote module, the main module comprising a control stage and a piezoelectric transmitter configured to emit ultrasonic signals, the control stage being configured to power the piezoelectric transmitter and command the piezoelectric transmitter to emit signals, the remote module comprising: a piezoelectric receiver configured to receive ultrasonic signals emitted by the piezoelectric transmitter; a sensing element configured to measure the parameters and generate a measurement signal containing at least one value of the parameters; and a measurement stage connected on one side to the piezoelectric receiver and on the other side to the sensing element, the measurement stage being configured to collect and store energy of the signals received by the piezoelectric receiver in order to power the sensing element, receive the measurement signals generated by the sensing element, extract the value of the measured parameter from the received measurement signals, and command the emission of a signal containing the extracted parameter value.

[0007] 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 or protective flanges, which may at least partially block electromagnetic waves, such as those used for Wi-Fi or Bluetooth.

[0008] In one embodiment, the piezoelectric receiver of the remote module is also a piezoelectric transmitter, and the piezoelectric transmitter of the main module is also a piezoelectric receiver. The measurement stage is configured to command the transmission of a signal containing these measurement values ​​via the piezoelectric transceiver of the remote module, and the control stage of the main module is configured to receive a signal containing these measurement values ​​via the piezoelectric transceiver of the main module.

[0009] Alternatively or additionally, the remote module includes an external communication level, which can be configured to command the transmission of signals containing these measurements via the external communication level. Thus, the measurements can be sent to an entity outside the measuring device for processing.

[0010] External communication stages can transmit using, for example, Bluetooth, Wi-Fi, 5G, or RFID communication protocols.

[0011] In one embodiment, the piezoelectric transmitter of the main module is configured to resonate at at least one predetermined frequency, the control stage is configured to generate a signal at said at least one predetermined frequency and transmit the generated signal to the piezoelectric transmitter of the main module, and the piezoelectric receiver of the remote module is configured to resonate at said at least one predetermined frequency. These technical features enable selective communication and, in particular, allow multiple remote modules to be used with a single main module, which improves performance and allows the frequency to be adjusted according to the normal operating mode and acoustic reflections of the motored machine.

[0012] The present invention also relates to an electric motor for a motor vehicle, the electric motor comprising a stator, a rotor and the 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 stator comprises the main module and the rotor comprises the remote module.

[0013] Preferably, the main module is mounted on and / or in the stator, and the remote module is mounted on and / or in the rotor.

[0014] In one embodiment, the rotor includes a hollow drum and a shaft, the hollow drum being equipped with magnetic elements within its internal space, and a sensing element being installed inside the drum.

[0015] 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. A piezoelectric receiver of the remote module is mounted on the end face or integrated into a cavity of the rotor. A piezoelectric transmitter of the main module may be mounted anywhere on the stator, and for example, on the portion of the stator facing the piezoelectric receiver.

[0016] In another embodiment, the rotor includes a roller mounted on a shaft, a piezoelectric transceiver of a remote module is mounted on the stator and faces the shaft (e.g., less than 50 cm from the shaft), and a sensing element is mounted inside the roller. Acoustic signals are then transmitted from the piezoelectric transceiver to the shaft, then through the shaft, and then into the roller to reach the sensing element, and vice versa.

[0017] In another embodiment, the rotor includes a drum and a hollow shaft passing through the drum and filled with a coolant (e.g., oil), a piezoelectric transceiver of the remote module is mounted inside the shaft in the coolant, and a sensing element is mounted inside the drum.

[0018] The present invention also relates to a motor vehicle battery comprising the measuring device as described above, wherein a remote module is mounted such that a sensitive element is placed within the battery.

[0019] 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 in at least one cell of the battery pack.

[0020] 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 in the fuel cell.

[0021] The present invention also relates to a motor vehicle that includes the measuring device described above.

[0022] In one embodiment, the vehicle is an electric vehicle or a hybrid electric vehicle, and includes the electric motor described above.

[0023] In one embodiment, the vehicle includes a battery or battery pack or fuel cell as described above.

[0024] 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 from the main module transmit ultrasonic signals via the piezoelectric transmitter of the main module. The ultrasonic signal is emitted by the piezoelectric transmitter of the main module. - The transmitted signal is received by the piezoelectric receiver of the remote module. - The energy of the received signal is collected and stored by the measurement stage of the remote module. - The measurement stage uses stored energy to power the sensitive components of the remote module. - The parameter is measured by a sensing element and a measurement signal is generated. - The generated measurement signal is transmitted to the measurement stage by the sensitive element. - The measurement signal is received by the measurement stage. - The measurement level extracts the values ​​of the measured parameters contained in the received measurement signal. - The measurement-level command transmits a signal including the extracted parameter values.

[0025] Preferably, the energy of the received signal is stored by the measurement stage until a predetermined threshold is reached, and then the stored energy is used to power the sensitive element. Attached Figure Description

[0026] 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 A first embodiment of the measuring device according to the present invention is illustrated schematically in a functional manner.

[0027] [ Figure 2 ] Figure 2 A second embodiment of the measuring device according to the invention is illustrated schematically in a functional manner.

[0028] [ Figure 3 ] Figure 3 An example of an electric machine according to the present invention is shown schematically.

[0029] [ Figure 4 ] Figure 4 An example of a battery according to the present invention is shown schematically.

[0030] [ Figure 5 ] Figure 5 An example of a battery pack according to the present invention is shown schematically.

[0031] [ Figure 6 ] Figure 6 An example of a fuel cell according to the present invention is illustrated schematically.

[0032] [ Figure 7 ] Figure 7An embodiment of the method according to the present invention is illustrated schematically. Detailed Implementation

[0033] 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.

[0034] Device 1 includes a main module 10 and a remote module 20.

[0035] Main Module 10 The main module 10 includes a control stage 110 and a piezoelectric transmitter 120.

[0036] The control stage 110 is configured to power the piezoelectric transmitter and command the piezoelectric transmitter to emit ultrasonic signals.

[0037] The piezoelectric transmitter 120 is configured to emit an ultrasonic signal when the control stage commands the piezoelectric transmitter to emit an ultrasonic signal.

[0038] Remote Module 20 The remote module 20 includes a piezoelectric receiver 210, a measuring stage 220, and a sensing element 230.

[0039] The piezoelectric receiver 210 is configured to receive ultrasonic signals emitted by the piezoelectric transmitter 120.

[0040] The measuring stage 220 is electrically connected to the piezoelectric receiver 210 on one side and to the sensing element 230 on the other side.

[0041] The measuring stage 220 is configured to collect and store the energy of the ultrasonic signal emitted by the piezoelectric transmitter 120 and received by the piezoelectric receiver 210.

[0042] The measurement stage 220 is configured to power the sensing element 230.

[0043] Measurement stage 220 is configured to receive measurement signal S generated by sensing element 230 during a single measurement or a series of measurements.

[0044] Measurement stage 220 is configured to extract measurement values ​​from the received measurement signal S.

[0045] Measurement stage 220 is configured to command the transmission of a signal including the measured value.

[0046] Sensing element 230 is configured to be powered by measuring stage 220.

[0047] Sensing element 230 is configured to measure the parameter.

[0048] Sensing element 230 is configured to generate a measurement signal S that includes one or more values ​​of the measured parameter and to transmit the signal.

[0049] Sensing element 230 is configured to transmit the generated measurement signal S to measurement stage 220.

[0050] In one embodiment, the piezoelectric receiver 210 of the remote module 20 is also a piezoelectric transmitter (transceiver), and the piezoelectric transmitter 120 of the main module 10 is also a piezoelectric receiver (transceiver). The measurement stage 220 is configured to command the transmission of an ultrasonic signal including the measured value (extracted from the measurement signal S) via the piezoelectric transceiver 210 of the remote module 20, and the control stage 110 of the main module 10 is configured to receive the signal containing the measured value via the piezoelectric transceiver 120 of the main module 10.

[0051] exist Figure 2 In another embodiment shown, the remote module 20 includes an external communication stage 240, and the measurement stage 220 is configured to command the transmission of a signal containing measurement parameter values ​​(extracted from the measurement signal S) via the external communication stage 240. This transmission can be performed, for example, via a Bluetooth or RFID communication interface known per se. In this case, the external communication stage 240 preferably includes a microcontroller that enables this transmission function.

[0052] In one embodiment: - The piezoelectric transmitter 120 of the main module 10 is configured to resonate at at least one predetermined frequency, and preferably at two predetermined frequencies (e.g., 200 kHz and 2 MHz). - Control stage 110 is configured to generate a signal at the at least one predetermined frequency and transmit the generated signal to piezoelectric transmitter 120 of main module 10, and - The piezoelectric receiver 210 of the remote module 20 is configured to resonate at the at least one predetermined frequency.

[0053] Preferably, the measurement stage 220 is configured to use the stored energy to power the sensing element 230 only when a predetermined energy storage threshold has been reached.

[0054] The remote module 20 may include more than one sensing element to measure multiple parameters.

[0055] The parameters measured (multiple) can be, for example, air temperature, air pressure, moisture content, current, mechanical force (stress), torque, etc.

[0056] Example of use of the measuring device according to the present invention Example 1: Electric Machine 300 Figure 3This is an example of an electric motor 300 for a motor vehicle. The electric motor 300 is configured to be installed in the vehicle to rotate the wheels of the vehicle.

[0057] The electric machine 300 includes a stator 310, a rotor 320, and the device 1 as described above.

[0058] The main module 10 is mounted on the stator 310, and the remote module 20 is mounted on the rotor 320.

[0059] The rotor 320 is configured to rotate about the longitudinal axis X.

[0060] 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.

[0061] The first shaft portion 321A includes an end face 321A1 extending orthogonally to the longitudinal axis of rotation X of the rotor 320. The piezoelectric receiver 210 of the remote module 20 is mounted on the end face 321A1, and the piezoelectric transmitter 120 of the main module 10 is mounted on the portion of the stator 310 facing the piezoelectric receiver 21.

[0062] Example 2: Battery 400 Figure 4 This is an example of a battery 400 used in motor vehicles.

[0063] 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.

[0064] 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.

[0065] Example 3: Battery pack 500 Figure 5 This is an example of a battery pack 500 used in motor vehicles.

[0066] 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.

[0067] Example 4: Fuel Cell 600 Figure 6 This is an example of a fuel cell 600 used in motor vehicles.

[0068] 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.

[0069] Examples of implementation methods Now refer to Figure 7 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.

[0070] First, when a parameter must be measured, in step E1, the control level 110 of the main module 10 commands the piezoelectric transmitter 120 of the main module 10 to emit an ultrasonic signal.

[0071] Then, in step E2, the piezoelectric transmitter 110 of the main module 10 emits the ultrasonic signal.

[0072] In step E3, the piezoelectric receiver 210 of the remote module 20 receives the transmitted signals and then transmits these signals to the measurement stage 220, which collects and stores the energy of the received signals in step E4.

[0073] The measurement stage 220 stores the energy of the received signal until a predetermined threshold is reached in step E5, and then uses the stored energy to power the sensing element 230 in step E6.

[0074] Then, the sensing element 230 measures the parameters and generates a measurement signal S in step E7, and then transmits the generated measurement signal S to the measurement stage 220 in step E8.

[0075] In step E9, measurement stage 220 receives the generated measurement signal S, and then in step E10 extracts one or more values ​​of the measured parameters contained in the received measurement signal S, such as one or more temperature values.

[0076] Then, in step E11, measurement stage 220 commands the transmission of a signal including the extracted parameter values.

[0077] Therefore, when the piezoelectric receiver 210 also performs the function of the piezoelectric transmitter, the measurement stage 220 can command the piezoelectric receiver to send the parameter values ​​extracted from the ultrasonic signal to the piezoelectric transmitter 120, which then also performs the function of the piezoelectric receiver, and then the piezoelectric transceiver 120 transmits the parameter values ​​to the control stage, which can use these parameter values ​​to control the system, such as controlling the rotational speed or position of the rotor 320 of the electric machine 300.

[0078] 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. A device (1) for measuring parameters of a motor vehicle, the device (1) comprising a main module (10) and a remote module (20), the main module (10) comprising a control stage (110) and a piezoelectric transmitter (120) configured to emit ultrasonic signals, the control stage (110) being configured to power the piezoelectric transmitter (120) and command the piezoelectric transmitter (110) to emit signals, the remote module (20) comprising: A piezoelectric receiver (210) is configured to receive ultrasonic signals emitted by the piezoelectric transmitter (120); A sensing element (230) configured to measure the parameter and generate a measurement signal (S) including at least one value of the parameter; and a measurement stage (220) connected on one side to the piezoelectric receiver (210) and on the other side to the sensing element (230), and the measurement stage configured to collect and store the energy of the signal received by the piezoelectric receiver (210) to power the sensing element (230), receive the measurement signal (S) generated by the sensing element (230), extract the value of the measured parameter from the received measurement signal (S), and command the transmission of a signal including the extracted parameter value.

2. The device (1) as claimed in claim 1, wherein, The piezoelectric receiver (210) of the remote module (10) is also a piezoelectric transmitter, and the piezoelectric transmitter (120) of the main module (10) is also a piezoelectric receiver. The measurement stage (220) is configured to command the transmission of a signal containing these measurement values ​​via the piezoelectric transceiver (210) of the remote module (20), and the control stage (110) of the main module (10) is configured to receive a signal containing these measurement values ​​via the piezoelectric transceiver (120) of the main module (10).

3. The device (1) as claimed in claim 1, wherein, The remote module (20) includes an external communication stage (240), and the measurement stage (220) is configured to command the transmission of signals containing these measurements via the external communication stage (240).

4. The device (1) as claimed in any of the preceding claims, wherein the piezoelectric transmitter (120) of the main module (10) is configured to resonate at at least one 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 piezoelectric transmitter (120) of the main module (10), and the piezoelectric receiver (210) of the remote module (20) is configured to resonate at the at least one predetermined frequency.

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 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 (X) of rotation of the rotor (320). A piezoelectric receiver (210) of the remote module (20) is mounted on the end face (321A1), and a piezoelectric transmitter (120) of the main module (10) is mounted on the portion of the stator (310) facing the piezoelectric receiver (210) of the remote module (20).

7. A motor vehicle battery pack (500) 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 placed in at least one battery of the battery pack (500).

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

9. 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 following steps: - The control level (110) of the main module (10) commands (E1) to transmit ultrasonic signals from the piezoelectric transmitter (120) of the main module (10). - The ultrasonic signal (E2) is emitted by the piezoelectric transmitter (120) of the main module (10). - The signal transmitted by (E3) is received by the piezoelectric receiver (210) of the remote module (20). - The energy of the received signal is collected and stored (E4) by the measurement stage (220) of the remote module (20). - The measurement stage (220) of the remote module (20) uses the stored energy to power the sensitive element (230) of the remote module (20) (E6). - The parameter is measured (E7) by the sensitive element (230) and a measurement signal (S) is generated. - The generated measurement signal (S) is transmitted (E8) to the measurement stage (220) by the sensitive element (230). - The measurement signal (S) is received (E9) by the measurement stage (220). - The value of the measured parameter contained in the measurement signal (S) received by the measurement stage (220) (E10) is extracted. - The measurement level (220) commands (E11) to transmit a signal including the extracted parameter values.

10. The method as claimed in the preceding claim, wherein, The energy of the received signal is stored (E4) by the measuring stage (220) until a predetermined threshold (E5) is reached, and then the stored energy is used to power the sensitive element (230) (E6).

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