Measuring device and stationary or mobile object

Abstract

The invention relates to a measuring device and a stationary object or a moving object. The object of the invention is to simplify the architecture of a measuring device intended to be attached to a wall in a flow of a moving object or a stationary object. The device comprises a support having a compartment provided with an opening at a free face to the outside of the support, the compartment housing a sensor therein, the support having a free face and a face intended to be in contact with the wall, the free face being opposite the face, the device comprising a cavity in which a printed circuit board is positioned, the compartment being provided with an opening in the cavity to the outside of the support. The cavity is made in the free face, i.e. the cavity opens to the free face, and the circuit board is arranged upside down in the cavity, i.e. the printed face is facing the inside of the support, the sensor attached to the circuit board hanging in the compartment. In this way, the unprinted face provides a smooth and flat aerodynamic surface.

Description

Technical Field

[0001] This invention relates to a measuring device suitable for attachment to a wall of a moving or stationary object located in a fluid flow to measure physical quantities. More specifically, the invention is applicable to measuring parameters used to characterize airflow over the surface of an aircraft. Background Technology

[0002] During flight testing, sensors are mounted on the outer surface of the aircraft to perform various types of measurements. The results allow for understanding the aircraft's behavior in flight and improving or validating its performance. Depending on a specific application, aerodynamic phenomena on the aircraft can be detected and located, for example.

[0003] Patent application FR 3015756 discloses a measuring device including a support having a compartment with an opening that opens outwardly on a free surface of the support where a sensor is disposed. The support includes a cavity formed on a surface intended for attachment to a wall, opposite to the free surface of the compartment opening thereto. A flexible printed circuit board is positioned on this free surface, connected to the sensor. The sensor compartment is enclosed by a membrane: this membrane provides an aerodynamic shape to the measuring device but adds an additional layer for which attachment must be provided. Summary of the Invention

[0004] The purpose of this invention is to simplify the structure of the measuring device while ensuring that the aerodynamic outer surface of the flow is not disturbed.

[0005] Therefore, the present invention relates to a measuring device intended to be attached to a wall of a moving or stationary object located in a flow, the measuring device comprising a support having a compartment housing a sensor, the support having a free surface and a surface intended to contact the wall, the free surface being opposite to the surface intended to contact the wall, the device comprising a cavity in which a printed circuit board is positioned, the compartment having an opening in the cavity leading to the outside of the support, characterized in that the cavity is formed in the free surface, i.e., the cavity opens to the free surface, and the circuit board is arranged inverted in the cavity, i.e., the printed surface faces the interior of the support, and the sensor attached to the circuit board is suspended in the compartment.

[0006] In this way, the surface in contact with the flow is as smooth and flat as possible; at the same time, the number of layers required to construct the device is reduced.

[0007] The present invention provides at least one of the following optional features, used individually or in combination.

[0008] A breathable but waterproof microporous membrane that can guide static charge toward the object covers the entire free surface and sides of the support.

[0009] The membrane is attached to the wall via a conductive double-sided adhesive tape to guide static charge.

[0010] The membrane is a woven aluminum material with micro-sized stitches.

[0011] The membrane is molded in one piece.

[0012] The printed circuit board has orifices aligned with each cavity.

[0013] The present invention also relates to a stationary or moving object having a wall located in a flow, the object being provided with at least one measuring device having one or more of the features described above.

[0014] The present invention provides at least one of the following optional features, used individually or in combination.

[0015] The support is attached to the wall by double-sided adhesive tape made of non-conductive silicone-acrylic acid.

[0016] The object is an aircraft. Attached Figure Description

[0017] Other objects, features, and advantages will become apparent from the following description of the invention, which is given by way of non-limiting example only with reference to the accompanying drawings, in which:

[0018] [ Figure 1 [This is a partial top view of the aircraft, and the measurement system according to the invention is mounted on the wing of the aircraft;]

[0019] [ Figure 2 This is a simplified schematic diagram of the arrangement of electronic components and the connections between said components according to an embodiment of a measurement system based on the present invention; for simplicity, not all components and connections are shown.

[0020] [ Figure 3 [Illustration] is a simplified schematic diagram of the cross-section of the measuring device of the system according to the present invention. Detailed Implementation

[0021] according to Figure 1 and Figure 2An illustrative application is shown, in which the measurement system 2 according to the invention is installed in a given region 4 of an aircraft 6: in the example shown, the system is installed on the wing 8. According to the illustrated embodiment, the system 2 has multiple parts, with a third part being optional. The first part includes a device 10 for measuring various physical quantities, adapted to be attached to a wall 12 on the exterior of the aircraft, and in the example shown above, attached to the outer wall of the wing 8 of the aircraft 6. The measurement system 2 can be included in… Figure 1 and Figure 2 One or more measuring devices 10, indicated by reference numerals 10', 10”, 10”', are connected together to form a device chain, allowing measurements to be performed over a large area. A second section terminates the measuring devices 10 via a loopback device 16 or an end device 17. The loopback device 16 allows for connections between open buses in the support structure, as will be seen further. The end device 17 terminates the last measuring device 10 in the chain: this end device includes a line termination impedance, allowing the electrical line formed by the series of measuring devices to be terminated. A third section includes an extension device 18, which is also located at the end of the measuring device. The loopback device 16, end device 17, or extension device 18 are present at the end of the measuring device. The extension device 18 includes a device capable of measurement like the measuring device 10. However, this extension device does not possess all the features of the measuring device 10: the extension device can be segmented to adapt the length of the associated measuring device 10 to the mounting environment of that measuring device. The fourth part includes a central unit 19, which powers one or more measuring devices 10 and extension devices 18, and also acquires signals from the one or more measuring devices 10 and extension devices 18. The power supply and acquisition unit 19 is positioned in contact with or at a distance from the measuring devices 10. Unit 19 is located inside the aircraft, and in the illustrated example, inside the wing. Unit 19 can be formed from a single block or several blocks; as in the illustrated embodiment, the unit includes a power supply unit 19A and a separate acquisition unit 19B, with units 19A and 19B connected together. Specifically, the power supply unit 19A can be a power source already present on the aircraft. The measurement system 2 sequentially includes the power supply and acquisition unit 19, one or more measuring devices 10' to 10"', and one or more end devices 16 and / or extension devices 18. The architecture of the measuring devices is of interest here.

[0022] Figure 3The measuring device 1, shown in cross-section, takes the form of a flexible support 20 for the sensor 22, allowing the measuring device to fit snugly against the contours of the aircraft 6. Each sensor is suitable for measuring physical quantities, such as, by way of non-limiting illustration, pressure, temperature, acceleration, mechanical force, etc. The sensors 22 can be grouped together in units that allow the measurement of several quantities, for example, grouped in a microelectromechanical system (MEMS). Hereinafter, the MEMS multi-parameter measurement unit will be referred to as sensor 22. The support 20 serves to provide a fairing for the sensor, so that the sensor does not require any specific housing, and the support also serves to hold the sensor as close as possible to the wall where the measuring device is arranged for measurement. The support can be made of a polymer material (e.g., flexible silicone or polyurethane) to fit snugly against the contours of the aircraft. This material also allows for the absorption of thermal stress. The material can be formed by extrusion, molding, machining, or any other known manufacturing method.

[0023] The support member 20 can be of any shape. Figure 3 In the example shown, the support member has an elongated shape with a trapezoidal cross-section. As previously mentioned, the support member can take any other shape. The sensor 22 is housed in the central portion of the support member at its maximum thickness. The support member 20 has six faces: a first face 24a intended to contact the wall of the aircraft; a second free face 24b parallel to and opposite to face 24a, intended to withstand the flow and located within the flow; and two side faces 24c and 24d forming the edges of the support member 20. The edges of the support member 20 have a gradually decreasing thickness and a triangular cross-section (e.g., Figure 3 As shown), in order to provide surfaces that only very slightly disturb aerodynamic flow; two surfaces 24e, 24f (in Figure 1 (See image) Forming two ends of the support member. One surface 24e is intended to connect to the power supply and acquisition unit 19 or another measuring device 10. The other surface 24f is intended to connect to the loopback device 16, the end device 17, or the extension device 18. Other embodiments with different arrangements are also possible, as described in the patent above. In one embodiment, surfaces 24e and 24f are parallel to each other; surfaces 24e and 24f are orthogonal to surfaces 24a and 24b. In this way, the measuring device can be more easily attached to the loopback device, the extension device, or the end device through their surfaces 24e and 24f. As mentioned above, the support member 20 can take any shape: therefore, surfaces 24e and 24f may not be flat, but may be chamfered or even have, for example, a complex shape. The shape of surface 24f should allow it to be directly and easily connected to the corresponding connection surface of the loopback device, the extension device, or the end device.

[0024] The support member 20 can accommodate multiple sensors 22. The sensors 22 are distributed uniformly or otherwise along the entire or partial length of the support member 20. According to one embodiment of the invention, the sensors 22 are distributed uniformly. Each sensor 22 is separated from adjacent sensors by a certain distance to prevent any interference with the operation of these sensors. Figure 2 As shown, the sensors 22 are arranged, for example, along the same line 23 parallel to the longitudinal direction of the support member 20. The support member 20 is provided with compartments 34 to accommodate the sensors 22: each compartment 34 accommodates one sensor 22. The shape of the compartment 34 corresponds to the shape of the sensor, such that the compartment fits snugly against the contour of its corresponding sensor without contacting it. The compartment 34 extends laterally through the support member 20 and opens to a surface 24a intended to be against a wall. According to one possible embodiment, the compartments 34 are formed by laser cutting.

[0025] like Figure 3 As shown, the support member 20 has a cavity 36 formed in a free surface 24b opposite to the surface intended to contact the aircraft wall. A compartment 34 for a sensor opens into said cavity 36. The cavity 36 houses a flexible printed circuit board 28 (commonly referred to as a flexible PCB or simply a flexible circuit). The cavity 36 has a shape corresponding to and closely abuts the shape of the circuit board 28. In the example shown, the circuit board 28 has an elongated shape that matches the shape of the support member 20. In the measuring device 10, the circuit board 28 opens onto the side of the support member 20 opposite to the surface 24b intended to be attached to the aircraft wall. In the embodiment shown, the circuit board 28 also opens onto surfaces 24e and 24f. The circuit board 28 and the support member 20 extend along the same longitudinal direction. The thickness of the cavity 36 is such that the free surface of the circuit board 28 is flush with the surface of the support member 20 opposite to the surface intended to contact the aircraft wall. Circuit board 28 is arranged inverted within support 20, with the printed side facing inwards and the flat, smooth opposite side facing outwards. In this way, support 20 and circuit board 28 form a single flat, smooth, and flexible aerodynamic surface, allowing convection disturbances to be kept to a minimum. Sensor 22 is soldered to the printed side of circuit board 28, and when circuit board 28 is inserted into support, sensor 22 is suspended in compartment 34, thus the measurement is undisturbed.

[0026] Cavity 36 is covered and sealed by a protective membrane 40 or film. The protective membrane 40 completely and perfectly covers the free surface 24b and sides 24c, 24d of the support without exceeding them. In the illustrated embodiment, membrane 40 is rectangular. This membrane is a breathable microporous membrane that is permeable to air but impermeable to water. The membrane can be supplied in rolls and therefore can be supplied integrally as a single membrane covering the desired total area. Membrane 40 is made of an antistatic material, allowing static charges that might accumulate due to air friction to conduct towards the aircraft fuselage coated with a lightly conductive paint. In the illustrated embodiment, protective membrane 40 is made of aluminum. This protective membrane is an aluminum microwoven fabric: because the protective membrane is woven, it allows air to pass through, but the micro-sized seams block water. The membrane is flexible enough to follow the contours of the aircraft along with the support. Membrane 40 is attached to the support 20 and wall 12 by conductive double-sided adhesive tape to guide static charges or any equivalent means. In addition, by covering all surfaces subjected to flow, membrane 40 provides aerodynamic surfaces for device 10.

[0027] The circuit board 28 has at least one aperture 42 aligned with each compartment 34, thereby allowing the pressure inlet required by certain types of sensors and allowing airflow from outside the device, located near the wall to which the device 10 is attached, to pass between the sensor 22 and the sensor. The aperture 42 is located between the sensor 22 and the wall of the compartment 34 where the sensor is located. Specifically, some sensors, such as pressure sensors, require openings to the airflow to allow the sensor to detect the pressure difference generated by the flow. These openings constitute pressure inlets. The apertures 42 are distributed on the membrane in the same manner as the sensors, such that each sensor 22 has a pressure inlet that allows it to make measurements. By fabricating the apertures 42 within the printed circuit board (outside any tracks, components, or other elements on the board), deformation does not occur as in known architectures that provide multiple apertures in flexible films: the circuit board provides rigidity, thereby allowing any deformation that could interfere with the pressure inlets to be avoided.

[0028] The support 20 is attached to the wall to be characterized by any known means, for example, by double-sided adhesive tape 44 made of non-conductive silicone-acrylic acid.

[0029] This invention is not limited to the aerospace field. The measurement system according to the invention can be used in many other technical fields, such as space vehicles, air vehicles, land vehicles, or marine vehicles. The invention can also be used on stationary objects placed in an airflow, such as a part of a vehicle being tested in a wind tunnel. The invention can also be used to characterize a wind tunnel by attaching the measuring device to one or more walls of the wind tunnel.

Claims

1. A measuring device intended to be attached to a wall (12) of a moving or stationary object in a flow, the measuring device comprising a support (20) having a compartment (34) housing a sensor (22), the support having a free surface (24b) and a surface (24a) intended to contact the wall, the free surface (24b) being opposite to the surface (24a), the device comprising a cavity (36) in which a printed circuit board (28) is positioned, the compartment (34) having an opening in the cavity (36) leading to the outside of the support, characterized in that, The cavity (36) is formed in the free surface (24b), i.e., the cavity opens to the free surface, and the printed circuit board (28) is arranged upside down in the cavity, i.e., the printed surface faces the interior of the support, and the sensor (22) attached to the printed circuit board (28) is suspended in the compartment (34).

2. The measuring device according to claim 1, characterized in that, A breathable but waterproof microporous membrane (40) that can direct static charge toward the moving or stationary object covers the entire free surface (24b) and sides (24c, 24d) of the support.

3. The measuring device according to claim 2, characterized in that, The breathable microporous membrane (40) is attached to the wall (12) by a conductive double-sided adhesive tape to guide static charge.

4. The measuring device according to claim 2, characterized in that, The breathable microporous membrane (40) is a woven aluminum material with micro-sized stitches.

5. The measuring device according to any one of claims 2 to 4, characterized in that, The breathable microporous membrane (40) is integrally formed.

6. The measuring device according to any one of claims 1 to 4, characterized in that, The printed circuit board (28) has apertures (42) aligned with each cavity (36).

7. The measuring device according to claim 5, characterized in that, The printed circuit board (28) has apertures (42) aligned with each cavity (36).

8. A stationary or moving object having a wall located in a flow, said stationary or moving object being provided with at least one measuring device according to any one of claims 1 to 7.

9. The stationary or moving object according to claim 8, characterized in that, The support (20) is attached to the wall by a double-sided adhesive tape (44) made of non-conductive silicone-acrylic acid.

10. A stationary or moving object according to any one of claims 8 and 9, characterized in that, The stationary or moving object is an aircraft.

Images