Piezoelectric measuring device for motor vehicles
The piezoelectric measuring device addresses inaccuracies in rotor temperature measurement by using wireless ultrasonic signals, ensuring precise temperature monitoring and improved motor control, thereby preventing damage.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
- Filing Date
- 2024-11-22
- Publication Date
- 2026-05-29
AI Technical Summary
Existing methods for measuring rotor temperature in electric motors are inaccurate, leading to potential performance losses and motor failure due to measurement errors of up to ±20°C, as direct wired probes are impractical due to rotor rotation.
A piezoelectric measuring device with a main and remote module, utilizing ultrasonic signals for wireless temperature measurement, allowing precise temperature monitoring without metallic barriers, and enabling communication via Bluetooth, Wi-Fi, or 5G.
Enhances motor control performance by providing accurate temperature readings close to the rotor, eliminating electromagnetic interference, and reducing the need for physical barriers, thus preventing motor damage.
Abstract
Description
Title of the invention: Piezoelectric measuring device for motor vehicles. Technical field
[0001] The present invention relates to the field of automobiles and more particularly concerns a piezoelectric measuring device 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 in a motor vehicle, said device comprising a main module and a remote module, said main module comprising a control stage and a piezoelectric transmitter configured to emit ultrasonic signals, said control stage being configured to electrically power said piezoelectric transmitter and to control the emission of signals by said piezoelectric transmitter, said remote module comprising a piezoelectric receiver configured to receive ultrasonic signals emitted by the piezoelectric transmitter, a sensing element configured to measure said parameter and generate a measurement signal comprising at least one value of said parameter, and a measurement stage, connected on the one hand to the piezoelectric receiver and on the other hand to said sensing element, and being configured to collect and store the energy of the signals received by the piezoelectric receiver, to electrically power the sensitive element, to receive a measurement signal generated by the sensitive element, to extract from said received measurement signal the values of the measured parameter and to control the emission of signals containing the extracted parameter values.
[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, a casing or protective flanges, which can at least partially block electromagnetic waves such as Wi-Fi or Bluetooth.
[0008] In one embodiment, the piezoelectric receiver of the remote module being also a piezoelectric transmitter and the piezoelectric transmitter of the main module being also a piezoelectric receiver, the measurement stage is configured to control the emission of signals containing the measured values via said piezoelectric transmitter-receiver of the remote module and the control stage of the main module is configured to receive the signals containing the measured values via said piezoelectric transmitter-receiver of the main module.
[0009] Alternatively or in addition, the remote module, comprising an external communication stage, allows the measurement stage to be configured to control the transmission of signals containing the measured values via said external communication stage. The measured values can thus be sent to an entity external to the measuring device for processing.
[0010] The external communication stage can, for example, transmit using a communication protocol such as Bluetooth, Wifi, 5G or RFID.
[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 to deliver 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 allow for communication selectivity and, in particular, the use of several remote modules with a single main module, which improves performance and allows the frequency to be adapted according to the natural modes of the electrical machine and acoustic reflections.
[0012] 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 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 comprises a hollow drum, provided in its internal space with magnetic elements, and an axle and the sensitive element is mounted inside said drum.
[0015] 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 piezoelectric receiver of the remote module is mounted on said end face or integrated into a cavity of the rotor, the piezoelectric emitter of the main module being able to be mounted anywhere on the stator, for example on a portion of the stator facing said piezoelectric receiver.
[0016] In another embodiment, the rotor comprising a drum mounted on a shaft, the piezoelectric transceiver of the remote module is mounted on the stator opposite said shaft, for example less than 50 cm away, and the sensing element is mounted inside said drum, the acoustic signals then circulating from the piezoelectric transceiver to the shaft, then through the shaft, then inside to reach the sensing element and vice versa.
[0017] In another embodiment, the rotor comprising a drum and a hollow shaft, passing through the drum and which is filled with a coolant, for example oil, the piezoelectric transmitter-receiver of the remote module is mounted inside said shaft, in the coolant, and the sensing element is mounted inside said drum.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] The invention also relates to a motor vehicle comprising a measuring device as previously described.
[0022] In one embodiment, the vehicle is an electric or hybrid electric vehicle and includes an electric machine as described above.
[0023] In one embodiment, the vehicle includes a battery or a group of batteries or a fuel cell as described above.
[0024] 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:
[0025] - control, by the control stage of the main module, of the emission of signals ultrasound via the piezoelectric emitter of the main module,
[0026] - emission, by the piezoelectric transmitter of the main module, of said signals ultrasound,
[0027] - reception, by the piezoelectric receiver of the remote module, of the emitted signals,
[0028] - collection and storage, by the measurement stage of the remote module, of the energy of signals received,
[0029] - power supply, via the measuring stage, from the stored energy, of the sensitive element of the remote module,
[0030] - measurement, by the sensitive element, of said parameter by generating a measurement signal,
[0031] - transmission, by the sensitive element, of said measurement signal generated at the stage of measure,
[0032] - reception, by the measurement stage, of the measurement signal,
[0033] - extraction, by the measurement stage, of the values of the measured parameter contained in the received measurement signal,
[0034] - control, by the measuring stage, of the emission of signals containing the values extracted parameters.
[0035] Preferably, the energy of the received signals is stored by the measurement stage until a predetermined threshold is reached before the sensing element is electrically powered from the stored energy. Brief description of the drawings
[0036] 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:
[0037] [Fig.1] Fig.1 schematically and functionally illustrates a first embodiment of the measuring device according to the invention.
[0038] [Fig.2] Fig.2 schematically illustrates, in a functional manner, a second embodiment of the measuring device according to the invention.
[0039] [Fig.3] Fig.3 schematically illustrates an example of an electrical machine according to the invention.
[0040] [Fig.4] Fig.4 schematically illustrates an example of a battery according to the invention.
[0041] [Fig. 5] [Fig. 5] schematically illustrates an example of a battery group according to the invention.
[0042] [Fig.6] Fig.6 schematically illustrates an example of a fuel cell according to the invention.
[0043] [Fig.7] Fig.7 schematically illustrates one embodiment of the process according to the invention. Description of the implementation methods
[0044] 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.
[0045] Device 1 comprises a main module 10 and a remote module 20.
[0046] Main Module 10
[0047] The main module 10 includes a control stage 110 and a piezoelectric transmitter 120.
[0048] The control stage 110 is configured to electrically supply said piezoelectric transmitter and to control the emission of ultrasonic signals by said piezoelectric transmitter.
[0049] The piezoelectric transmitter 120 is configured to emit ultrasonic signals when commanded to do so by the control stage.
[0050] Remote Module 20
[0051] The remote module 20 includes a piezoelectric receiver 210, a measuring stage 220 and a sensitive element 230.
[0052] The piezoelectric receiver 210 is configured to receive ultrasonic signals emitted by the piezoelectric transmitter 120.
[0053] The measuring stage 220 is electrically connected on one side to the piezoelectric receiver 210 and on the other side to the sensitive element 230.
[0054] The measuring stage 220 is configured to collect and store the energy of the ultrasonic signals emitted by the piezoelectric transmitter 120 and received by the piezoelectric receiver 210.
[0055] The measuring stage 220 is configured to electrically supply the sensitive element 230.
[0056] The measuring stage 220 is configured to receive a measurement signal S generated by the sensitive element 230 during a measurement or a series of measurements.
[0057] The measuring stage 220 is configured to extract the measured values from the received measuring signal S.
[0058] The measuring stage 220 is configured to control the emission of signals containing the measured values.
[0059] The sensitive element 230 is configured to be electrically powered by the measuring stage 220.
[0060] The sensitive element 230 is configured to measure said parameter.
[0061] The sensitive element 230 is configured to generate a measurement signal S comprising the value(s) of the measured parameter and to transmit said signal.
[0062] The sensitive element 230 is configured to transmit the measurement signal S generated to the measurement stage 220.
[0063] In one embodiment, the piezoelectric receiver 210 of the remote module 20 being also a piezoelectric transmitter (transmitter-receiver) and the piezoelectric transmitter 120 of the main module 10 being also a piezoelectric receiver (transmitter-receiver), the measuring stage 220 is configured to control the emission of ultrasonic signals containing the measured values (extracted from the measurement signal S) via the piezoelectric transmitter-receiver 210 of the remote module 20 and the control stage 110 of the main module 10 is configured to receive the signals containing the measured values via said piezoelectric transmitter-receiver 120 of the main module 10.
[0064] In another embodiment, illustrated in [Fig. 2], the remote module 20 includes an external communication stage 240, and the measurement stage 220 is configured to control the transmission of signals containing the measured parameter values (extracted from the measurement signal S) via said external communication stage 240. This transmission can, for example, be carried out on a communication interface of the Bluetooth or RFID type, which are known per se. In this case, the external communication stage 240 preferably includes a microcontroller enabling the implementation of this transmission function.
[0065] In one embodiment:
[0066] - the piezoelectric emitter 120 of the main module 10 is configured for resonate at at least one predetermined frequency, preferably at two predetermined frequencies, for example 200 kHz and 2 MHz,
[0067] - the control stage 110 is configured to generate a signal to said at least one predetermined frequency and to deliver the generated signal to the piezoelectric transmitter 120 of the main module 10, and
[0068] - the piezoelectric receiver 210 of the remote module 20 is configured to resonate at least a predetermined frequency.
[0069] Preferably, the measuring stage 220 is configured to electrically supply the sensing element 230 from the stored energy only when a predetermined energy storage threshold has been reached.
[0070] The remote module 20 can include more than one sensitive element to measure several parameters.
[0071] The parameter(s) measured may, for example, be air temperature, air pressure, humidity level, intensity of an electric current, a mechanical force (stress), a torque, etc.
[0072] Examples of use of the measuring device according to the invention
[0073] Example 1: 300 electric machine
[0074] 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.
[0075] The electric machine 300 comprises a stator 310, a rotor 320 and a device 1 as previously presented.
[0076] The main module 10 is mounted on the stator 310 and the remote module 20 is mounted on the rotor 320.
[0077] The rotor 320 is configured to rotate around a longitudinal axis X.
[0078] 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.
[0079] The first portion of axis 321A comprises an end face 321 Al extending orthogonally to the longitudinal axis X of rotation of the rotor 320. The piezoelectric receiver 210 of the remote module 20 is mounted on said end face 321A1 and the piezoelectric emitter 120 of the main module 10 is mounted on a portion of the stator 310 facing said piezoelectric receiver 21.
[0080] Example 2: 400 battery
[0081] The [Fig.4] is an example of a 400 battery for a motor vehicle.
[0082] The main module 10 is placed at a distance from the battery 400 while the module remote 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.
[0083] 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 of the 400 battery with the 230 sensitive element, as in example 1 of the electric machine.
[0084] Example 3: 500 battery group
[0085] The [Fig.5] is an example of a 500 battery group for a motor vehicle.
[0086] 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.
[0087] Example 4: 600 fuel cell
[0088] The [Fig.6] is an example of a 600 fuel cell for a motor vehicle.
[0089] 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.
[0090] Example of implementation
[0091] 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.
[0092] First, when it is necessary to measure the parameter, the control stage 110 of the main module 10, controls in a step El the emission of ultrasonic signals by the piezoelectric transmitter 120 of the main module 10.
[0093] The piezoelectric emitter 110 of the main module 10 then emits said ultrasonic signals in a step E2.
[0094] The piezoelectric receiver 210 of the remote module 20 receives the signals emitted in a stage E3 and then transmits them to the measurement stage 220 which collects and stores the energy of the signals received in a stage E4.
[0095] The measuring stage 220 stores the energy of the received signals until it reaches a predetermined threshold in a step E5 and then electrically powers the sensitive element 230 from the stored energy in a step E6.
[0096] The sensitive element 230 then measures the parameter by generating a measurement signal S in a step E7 and then transmits said generated measurement signal S to the measurement stage 220 in a step E8.
[0097] The measuring stage 220 receives the measurement signal S generated in a step E9 and then extracts the value or values of the measured parameter, for example the temperature value or values, contained in the measurement signal S received in a step E10.
[0098] The measurement stage 220 then controls, in an Eli step, the emission of signals containing the extracted parameter values.
[0099] To do this, the measuring stage 220 can control the piezoelectric receiver 210 when the latter also has the function of a piezoelectric transmitter in order to send the extracted parameter values in ultrasonic signals to the piezoelectric transmitter 120 which then also has the function of a piezoelectric receiver then the piezoelectric transmitter-receiver 120 transmits the parameter values to the control stage which can use them to control a system such as for example the rotation speed or the position of the rotor 320 of an electric machine 300.
[0100] 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 piezoelectric transmitter (120) configured to emit ultrasonic signals, said control stage (110) being configured to electrically supply said piezoelectric transmitter (120) and to control the emission of signals by said piezoelectric transmitter (110), said remote module (20) comprising a piezoelectric receiver (210) configured to receive ultrasonic signals emitted by the piezoelectric transmitter (120), a sensing element (230) configured to measure said parameter and generate a measurement signal (S) comprising at least one value of said parameter, and a measuring stage (220), connected on one side to the piezoelectric receiver (210) and on the other side to said sensing element (230),and being configured to collect and store the energy of the signals received by the piezoelectric receiver (210), to electrically power the sensing element (230), to receive a measurement signal (S) generated by the sensing element (230), to extract from said received measurement signal (S) the values of the measured parameter and to control the emission of signals containing the extracted parameter values.
2. Device (1) according to 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 measuring stage (220) is configured to control the emission of signals containing the measured values via said piezoelectric transmitter-receiver (210) of the remote module (20) and the control stage (110) of the main module (10) is configured to receive the signals containing the measured values via said piezoelectric transmitter-receiver (120) of the main module (10).
3. Device (1) according to claim 1, wherein, the remote module (20) comprising an external communication stage (240), the measurement stage (220) is configured to control the transmission of signals containing the measured values via said external communication stage (240).
4. Device (1) according to any one of the preceding claims, wherein the piezoelectric emitter (120) of the main module (10) is configured to resonate at least one predetermined frequency, the control stage (110) is configured to generate a signal at said at least one predetermined frequency and to deliver the generated signal to the piezoelectric emitter (120) of the main module (10), and the piezoelectric receiver (210) of the remote module (20) is configured to resonate at said at least one predetermined frequency.
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 rotor (320) comprising 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 shaft portion (321A) having an end face (321A1) extending orthogonally to the longitudinal axis (X) of rotation of the rotor (320), the piezoelectric receiver (210) of the remote module (20) is mounted on said end face (321A1) and the piezoelectric emitter (120) of the main module (10) is mounted on a portion of the stator (310) facing said piezoelectric receiver (210) of the remote module (20).
7. Battery group (500) for 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 in at least one battery of the battery group (500).
8. Motor vehicle comprising a measuring device (1) according to any one of claims 1 to 4.
9. 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 main module (10), of the emission of ultrasonic signals by the piezoelectric transmitter (120) of the main module (10), - emission (E2), by the piezoelectric transmitter (120) of the main module (10), of said ultrasonic signals, - reception (E3), by the piezoelectric receiver (210) of the remote module (20), of the emitted signals, - collection and storage (E4), by the measurement stage (220) of the remote module (20), of the energy of the received signals, - power supply (E6), by the measurement stage (220) of the remote module (20), from the stored energy, of the sensing element (230) of the remote module (20), - measurement (E7), by the sensing element (230), of said parameter by generating a measurement signal (S), - transmission (E8), by the sensing element (230), of said measurement signal (S) generated at the measurement stage (220), - reception (E9), by the measurement stage (220), of the measurement signal (S), - extraction (E10), by the measurement stage (220),values of the measured parameter contained in the received measurement signal (S), - control (El 1), by the measurement stage (220), of the emission of signals containing the extracted parameter values.
10. Method according to the preceding claim, wherein the storage (E4), by the measuring stage (220), of the energy of the received signals is carried out until a predetermined threshold (E5) is reached before electrically supplying (E6) the sensitive element (230) from the stored energy.