PRESSURE AND / OR TEMPERATURE MEASUREMENT ON AN AIRCRAFT PROPULSION SYSTEM

Abstract

The invention relates to a measuring installation (100) comprising: - a component (112) of an aircraft propulsion system (102); and - a measuring device (120). The measuring device (120) comprises: - a flexible electronic board (202) fixed to the component (112) of the propulsion system (102), the flexible electronic board (202) comprising: a flexible substrate strip (204), and conductive tracks (206) carried by the flexible substrate strip (204), and - pressure and / or temperature sensors (2121-6), these sensors (2121-6) comprising microelectromechanical systems and being mounted on the flexible substrate strip (204). Figure for the abstract: Fig. 1

Description

Title of the invention: PRESSURE AND / OR TEMPERATURE MEASUREMENT ON AN AIRCRAFT PROPULSION SYSTEM Technical field of the invention

[0001] The present invention relates to a pressure and / or temperature measurement installation on an aircraft propulsion system. Technological background

[0002] The pressure measurement on the surface of an aerodynamic profile of a component of a propulsion system (such as a cowling or nacelle) or of a wind tunnel model of this component is traditionally performed using small orifices (0.3 to 0.5 mm in diameter) connected to a sensor or transmitter via a thin tube generally called a capillary tube. This well-established technique relies on a wide range of pressure sensors and scanners, the choice of which depends on the pressure level to be measured, the response time (particularly for unsteady pressure measurements), size, and cost.

[0003] To obtain detailed information on the pressure distribution across the surface of the test machine, a large number of ports are therefore necessary to achieve surface discrimination. These are often connected to a common transmitter via a scanning device. One or more pressure sensors are installed on the switch or in the scanner, and a capillary tube carries the pressure from each measurement point to each sensitive element of the sensor. Consequently, a large number of tubes or capillaries are required, and the greater the number of measurement points, the more capillaries and sensors must be integrated into the machine.

[0004] Electronic scanners significantly improve the scanning rate. Composed of a set of sensors, each connected to a pressure orifice via a capillary, their pressure output signals are then sent to a digital multiplexer which selectively digitizes them.

[0005] Small electronic scanners can be placed close to the orifices to reduce the length of the capillaries and therefore the response time. Nevertheless, the volume occupied by the capillaries and the complexity of integrating a scanner remain significant.

[0006] In the context of new propulsion system architectures, design offices wish to have a larger number of measurement points (several hundred in different areas). However, the use of capillaries in certain Areas, particularly around moving parts, are not always possible due to the high density of measurement points required.

[0007] It may therefore be desirable to provide a measurement installation which makes it possible to reduce the number of capillaries or to eliminate them and reduce the intrusive aspect of the measurement. Summary of the invention

[0008] A measuring installation is therefore proposed comprising: - a component of an aircraft propulsion system; and - a measuring device comprising: • a flexible electronic board fixed to the propulsion system component, the flexible electronic board comprising: a flexible substrate strip, and conductive tracks carried by the flexible substrate strip, and • pressure and / or temperature sensors, these sensors comprising microelectromechanical systems and being mounted on the flexible substrate strip.

[0009] Thus, thanks to the use of the communication bus, only one communication line is needed to retrieve the measurements from all the sensors of the measuring device.

[0010] The invention may further include one or more of the following optional features, according to any technically possible combination.

[0011] Optionally, the measuring device includes a communication bus intended to be connected to a remote measuring bench, the sensors being connected to the communication bus to communicate with the measuring bench.

[0012] Optionally also, some of the conductive tracks are part of the communication bus.

[0013] Optionally, each of the sensors is also designed to present an address from among a predefined number of possible addresses, the sensors being more numerous than the predefined number of possible addresses so that two sensors present the same address, and the measuring device further includes an addressing circuit connected to the communication bus and to the digital sensors, the addressing circuit being designed to allow addressing of each of the digital sensors from the communication bus.

[0014] Optionally, the addressing circuit also includes, for each digital sensor, an address translator connected to the communication bus and to the digital sensor in question, and designed to transfer communications between the communication bus and the digital sensor under consideration, address translators presenting different addresses.

[0015] Optionally also, the addressing circuit includes, for each of several groups of digital sensors, a multiplexer connected to the communication bus and to each of the digital sensors in the group considered, each multiplexer being designed to activate only one at a time of the digital sensors connected to it, according to a request received from the communication bus.

[0016] Optionally also, the measuring device includes several flexible electronic boards, the communication buses of these flexible electronic boards being connected in series, for example by conductive wires, for example by two pairs of conductive wires in the case of I2C or I3C communication buses.

[0017] Optionally, the digital sensors are also aligned along the flexible substrate strip, for example with a regular spacing.

[0018] Optionally also, the measuring device further includes spacers placed respectively between the digital sensors so that the digital sensors are flush with the spacers.

[0019] Optionally, the measuring device also includes a transceiver connected to the communication bus and designed to perform a physical layer conversion between signals from the communication bus and signals intended to pass over a communication line connected to the measuring device.

[0020] Optionally, the measuring installation also includes: - the communication line; and - a measuring bench comprising: • a communication bus, • a data acquisition device connected to the communication bus, • a transceiver connected to the communication bus and designed to perform a physical layer conversion between signals from the communication bus and signals intended to pass over the communication line connected to the measurement bench. Brief description of the figures

[0021] The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the accompanying drawings in which: - [Fig. 1] is a three-dimensional view of a measuring installation according to the invention, - [Fig.2] is a functional view of a measurement system for the measurement installation, comprising a measuring device, a measuring bench, and a communication line between them. - Figure 3 is a functional view of a first example of an addressing device in the measuring device. - Figure 4 is a functional view of a second example of the addressing device, - Figure 5 illustrates two ways of attaching the measuring device to a surface of a part of an aircraft propulsion system, - Figure 6 is a three-dimensional view of one embodiment of the measuring device, illustrating several flexible electronic circuits in series, and - Fig. 7 is a cross-sectional view of one embodiment of the measuring device, illustrating spacers between digital sensors of the measuring device. Detailed description of the invention

[0022] With reference to [Fig.1], a measuring installation 100 in which the invention is implemented will now be described.

[0023] The measuring installation 100 includes first of all an aircraft propulsion system 102 comprising a turbomachine 104 and a nacelle 106 surrounding the turbomachine 104.

[0024] The nacelle 106 includes, for example, from front to back, an air inlet 108, two complementary hoods 110, 112 and two complementary reversers 114, 116.

[0025] The measuring installation 100 further comprises a measuring system 118 comprising a measuring device 120 fixed on an outer face of a part of the nacelle 106, for example an outer face of one of the hoods 110, 112, a measuring bench 122 distant from the propulsion system 102, and a communication line 124 connecting the measuring bench 122 to the measuring device 120.

[0026] With reference to [Fig.2], the measuring system 118 will now be described in more detail.

[0027] The measuring device 120 first includes a flexible electronic card 202, such as a flexible printed circuit board.

[0028] The flexible electronic board 202 thus comprises a flexible substrate strip 204. "Flexible" means, for example, "capable of following a concave or convex curved surface with a radius of curvature of up to 25 mm." The flexible substrate strip 204 is, for example, made of a plastic such as polyimide. The flexible substrate strip 204 has, for example, a thickness of between 0.1 mm and 3 mm, and more. specifically between 0.1 mm and 0.2 mm. The flexible substrate strip 204 has a width, for example, between 5 mm and 50 mm. The flexible substrate strip 204 has a length, for example, between 0.1 m and 1 m.

[0029] The flexible electronic board 204 further includes conductive tracks 206 carried by the flexible substrate strip 204, for example printed on the flexible substrate strip 204. These conductive tracks 206 are in particular used to connect components carried by the flexible substrate strip 204 and which will be described later.

[0030] The flexible electronic card 202 includes a communication bus 208 formed at least in part by some of the conductive tracks 206.

[0031] The measuring device 120 further comprises digital pressure and / or temperature sensors 212x.6, six in the illustrated example, but there could be more. These digital sensors 212i_6 are microelectromechanical sensors (MEMS) mounted on the flexible substrate strip 204. The digital sensors 212x6 are thus integrated into a surface of the flexible substrate strip 204 using, for example, the same techniques as those employed for the manufacture and assembly of standard flexible electronic boards.

[0032] The digital sensors 212x6 are, for example, aligned along the flexible substrate strip 204, with a spacing (also called center-to-center distance) that can be constant or variable. This spacing between the digital sensors 212x6 depends strongly on the pressure and / or temperature field being studied. Thus, depending on the requirements and the required density of digital sensors 212x6, the dimensions of the flexible substrate strip 204 can be adjusted.

[0033] The sensors 212x 6 are connected, directly or indirectly, to the communication bus 208 to communicate with the measuring bench 122, in particular to transmit their measurements.

[0034] The communication bus 208 is, for example, an I2C communication bus and / or an I3C communication bus, since many digital sensors available on the market use these communication buses. If a more efficient I2C digital sensor becomes available in the future, it could advantageously replace the 212x6 digital sensors currently used without requiring significant modification to the rest of the flexible electronic board 204.

[0035] Generally, the manufacturer of the 212x_6 digital sensors assigns each 212x_6 digital sensor an address from a limited number of possible addresses, for example, from four possible addresses. Each 212x_6 digital sensor then appears on the network with the address that has been assigned to it. However, to obtain a For high measurement density, it is desirable to provide a large number of digital sensors in the flexible electronic board 202, for example more than twenty.

[0036] Due to the limited number of possible addresses, a high number of 212x 6 digital sensors implies that 212r 6 digital sensors have the same address, whereas an I2C or I3C communication bus manages up to one hundred and twenty-seven different addresses.

[0037] Thus, the measuring device 120 preferably further comprises an addressing circuit 216 connected to the communication bus 208 and to the digital sensors 212i 6, the addressing circuit 216 being designed to allow addressing of each of the sensors 212x 6 from the communication bus 208.

[0038] The measuring device 120 may further include a connector 218 to which the communication line 124 is designed to be connected.

[0039] Furthermore, the measuring bench 122 includes first of all a communication bus 220, preferably of the same type as the communication bus 208 of the device 120, i.e. for example an I2C communication bus and / or an I3C communication bus.

[0040] The measuring bench 122 further includes a data acquisition device 222 connected to the communication bus 220, designed to query each of the digital sensors 212x 6 to obtain their measurements, via the communication bus 220.

[0041] The measuring bench 122 further includes a connector 226 to which the communication line 124 is designed to be connected.

[0042] It may happen that the communication bus 208 does not allow communication over long distances. For example, if an I2C communication bus is used, it does not allow communication over distances greater than 5 m. An I3C communication bus also has a length limit. However, the measuring device 120 and the measuring bench 122 may be separated by a distance exceeding ten meters, which is hardly compatible with the I2C communication bus. In this case, it is therefore necessary to find a solution to extend the I2C communication bus over long distances.

[0043] Thus, the measuring device 120 and the measuring bench 122 preferably each comprise a transceiver 230, 232 connected to the communication bus 208, respectively 220, and designed to perform a conversion from the physical layer of the I2C protocol of the signals of the communication bus 208, respectively 220, to the physical layer of another protocol of the signals on the communication line 124, the signals on the communication line being compatible with a large length of the communication line 124, for example with a length exceeding ten meters.

[0044] For example, each of the 230, 232 transceivers is designed to perform a conversion between I2C communication bus signals and CAN signals. For this purpose, the LT3960 transceiver from Analog Devices can be used, which is a high-speed transceiver that allows an I2C bus to be extended over a significant distance and at speeds up to 400 kbps using the physical layer of the CAN protocol, called CanI2C.

[0045] In this case, preferably, the transceiver 230 of the measuring bench 122 is placed in master mode, while the transceiver 232 of the measuring device 122 is placed in slave mode.

[0046] In addition, the supply line 124 comprises three pairs of twisted conducting wires: a first pair 124A for transmitting a differential clock signal, a second pair 124B for transmitting a differential data signal and a third pair 124C for transmitting a differential power supply signal.

[0047] Thus, by interfacing the two transceivers 230, 232, it is possible to transmit measurements from the communication bus 208 of the measuring device 120 to the measuring bench 122 over a significant distance (i.e., several meters) via intermediate physical layer signals, in particular CanI2C layer signals. This latter case was successfully tested with a 35-meter communication line 124.

[0048] Furthermore, the transceivers 230, 232, such as the LT3960, may have the advantage of integrating a voltage converter or LDO capable of supplying a 3.3 VDC voltage to all the digital sensors 212i_6. This avoids the need for DCDC converters on the flexible electronic board 202, and thus greatly reduces the number of components on the flexible electronic board 202.

[0049] With reference to [Fig.3], in certain embodiments, the addressing circuit 216 comprises, for each sensor 212i.6, an address translator 302i_6 connected to the first bus 208 and to the sensor 212x 6 considered.

[0050] Each address translator 302i_6 is designed to present on the communication bus 208 an address different from the address of the associated digital sensor 212b 6 (transparent to the communication bus 208), the address translators 302i_6 presenting different addresses. The address presented by each address translator 302i_6 is, for example, defined by the choice of one or more resistors connected to the address translator 302i_6.

[0051] For example, address translators 302^ could be the LT4316 address translator from Analog Devices. Unfortunately, the LT4316 address translator is designed to operate in a temperature range of -40°C to +85°C, and Analog Devices does not currently offer an alternative or components designed for higher temperatures. However, some applications may ultimately reach +120°C transiently.

[0052] With reference to [Fig. 4], for example, to address this operating temperature issue, the addressing circuit 216 can include, for each of several sensor groups 212i_3, 2124.6, a multiplexer 40212 connected to the I2C bus and to each of the sensors in the group 212i_3, 2124.6 under consideration. The 40212 multiplexers are designed to each present a different address on the communication bus 208, and furthermore to activate only one of the connected digital sensors at a time, according to a request received from the communication bus 208. This avoids any address conflicts, even with digital sensors having the same address. Integrating 402i_2 multiplexers onto the flexible circuit board 202 significantly reduces the number of components required.

[0053] For example, 402^ multiplexers are TCA9548APWR multiplexers which have eight channels (eight digital sensors can be connected to it). And which operate over the temperature range of -40°C to +125°C.

[0054] With reference to [Fig.5], the flexible electronic board 202 is for example fixed on the outer face by means of a double-sided adhesive 502 interposed between the outer face and the flexible substrate strip 204 (top drawing) or by means of one or more single-sided adhesives 504 covering both the outer face and the flexible substrate strip 204 (bottom drawing).

[0055] With reference to [Fig. 6], in certain embodiments, several flexible electronic boards 202A-C may be provided, each like the flexible electronic board 202 described previously. In this case, the communication buses 208 of these flexible electronic boards 202A-C are connected in series by conductive wires 602, 604, for example by two pairs of conductive wires in the case of I2C or I3C communication buses. The conductive wires 602, 604 are, for example, soldered to the conductive tracks forming the communication buses 208 or connected to them by means of connectors (not shown).

[0056] With reference to [Fig. 7], in certain embodiments, the measuring device 120 may further comprise spacers 702 positioned between the sensors 212x6 so that the digital sensors 2121f) are flush with the spacers 702. The latter may be separate parts or parts of a single overall piece. The presence of the spacers 702 will maintain an aerodynamic airflow Fl over the digital sensors, similar to the airflow that would be present in the absence of the measuring device 120. This configuration (called "flush / non-flush") makes it possible to maintain the integrity of the airflow during testing.

[0057] The spacers 702 can be made of polymer or metal, for example.

[0058] In conclusion, it should be noted that the invention is not limited to the embodiments described above. It will indeed be apparent to those skilled in the art that various modifications can be made to the embodiments described above, in light of the information just disclosed to them.

[0059] In particular, the digital sensors could be digital temperature sensors such as the TMP117 digital sensor from Texas Instruments, or even digital temperature and pressure sensors.

[0060] In the detailed presentation of the invention given above, the terms used shall not be interpreted as limiting the invention to the embodiments set forth in this description, but shall be interpreted as including all equivalents which can be foreseen by a person skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

Demands

1. Measurement installation (100) comprising: - a part (112) of an aircraft propulsion system (102); and - a measurement device (120) comprising: • a flexible electronic card (202) fixed to the part (112) of the propulsion system (102), the flexible electronic card (202) comprising: a flexible substrate strip (204), and conductive tracks (206) carried by the flexible substrate strip (204), and • pressure and / or temperature sensors (212i_6) designed to be connected to a communication bus (208), these sensors (212i_6) comprising microelectromechanical systems and being mounted on the flexible substrate strip (204).

2. Measurement installation (100) according to claim 1, wherein the measurement device (120) includes a communication bus (208) intended to be connected to a remote measurement bench (122), the sensors (212i.6) being connected to the communication bus (208) to communicate with the measurement bench (122).

3. Measurement installation (100) according to claim 2, wherein some of the conductive tracks (206) are part of the communication bus (208).

4. Measurement installation (100) according to claim 3, wherein each of the sensors (212i_6) is designed to present an address from among a predefined number of possible addresses, the sensors (212i.6) being more numerous than the predefined number of possible addresses such that at least two sensors (212i.6) present the same address, and wherein the measurement device (120) further comprises an addressing circuit (216) connected to the communication bus (208) and to the digital sensors (212i_6), the addressing circuit (216) being designed to allow addressing of each of the digital sensors (212i.6) from the communication bus (208).

5. A measuring installation (100) according to claim 4, wherein the addressing circuit (216) comprises, for each digital sensor (212i_6), an address translator (302b6) connected to the communication bus (208) and to the digital sensor (212i_6) under consideration and designed to transfer communications between the communication bus (208) and the digital sensor (212i_6) under consideration, the address translators (302i_6) having different addresses.

6. Measurement installation (100) according to claim 4, wherein the addressing circuit (216) comprises, for each of several groups (2121.3, 2124_6) of digital sensors, a multiplexer (402b2) connected to the communication bus (208) and to each of the digital sensors in the group (2121.3, 2124_6) considered, each multiplexer (402b2) being designed to activate only one at a time of the digital sensors (2121.3, 2124_6) connected to it, according to a request received from the communication bus (208).

7. Measurement installation (100) according to any one of claims 2 to 6, wherein the measurement device (120) comprises several flexible electronic boards (202A-C), the communication buses (208) of these flexible electronic boards (202A-C) being connected in series, for example by conductive wires (602, 604), for example by two pairs of conductive wires in the case of I2C or I3C communication buses.

8. Measurement installation (100) according to any one of claims 1 to 7, wherein the digital sensors (212i_6) are aligned along the flexible substrate strip (204), for example with a regular spacing.

9. Measuring installation (100) according to any one of claims 1 to 8, wherein the measuring device (120) further comprises spacers (702) placed respectively between the digital sensors (212i.6) so that the digital sensors (212i-6) are flush with the spacers (702).

10. Measurement installation (100) according to any one of claims 1 to 9, wherein the measurement device (120) further comprises a transceiver (230) designed to be connected to the communication bus (208) and designed to perform a physical layer conversion between signals from the communication bus (208) and signals intended to be transmitted over a communication line (124) connected to the measurement device (120).

11. Measuring installation (100) according to claim 10, further comprising: - the communication line (124); and - a measuring bench (122) comprising: • a communication bus (220), • a data acquisition device (222) connected to the communication bus (220), • a transceiver (230) connected to the communication bus (220) and designed to perform a physical layer conversion between signals from the communication bus (220) and signals intended to pass over the communication line (124) connected to the measurement bench (120).

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