Measuring device with double data acquisition circuit

Abstract

A measuring device comprises a substrate having a housing with an exposure opening in which a sensor is arranged, the substrate comprising a cavity which accommodates a flexible printed circuit. The device is mounted on a surface to characterize the fluid flow at that surface. The circuit uses a layered bus comprising two data communication buses exposed at both longitudinal ends of the substrate and an internal data acquisition bus linking the control circuits together, each control circuit being connected to one of the communication buses, the sensors being connected to the data acquisition bus in a distributed manner on both sides of each control circuit. In this way, data from the sensors can be transmitted to the two surrounding circuits and acquired even if one of them fails. The invention also discloses a measuring system comprising the above measuring device, an object equipped with the measuring system and a corresponding measuring method.

Description

Technical Field

[0001] This invention relates to a measuring device capable of being attached to a surface of a moving or stationary object located within 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 aircraft's outer surface to perform various types of measurements. Studying the results allows for understanding the aircraft's behavior in flight and improving or validating its performance characteristics. Depending on a specific application, aerodynamic phenomena on the aircraft can be detected and located, for example.

[0003] A measuring device is known from patent application FR 3015664 filed by Airbus Operations SAS. This measuring device includes a substrate having a housing with an externally exposed opening into which a sensor is disposed. The substrate includes a cavity housing a flexible printed circuit, on which a single control circuit is disposed directly connected to each sensor. Multiple measuring devices can be linked together to be distributed over a large area, such as a large area of ​​a wing segment. Accordingly, multiple control circuits are also connected together. When a control circuit receives data from a sensor connected to it, it collects the data and transmits it to the next control circuit. However, if one control circuit fails, data cannot be recovered from the sensor it was responsible for, or from subsequent sensors. Summary of the Invention

[0004] The purpose of this invention is to provide a measuring device that allows data from most sensors in a circuit to be recovered in the event of a failure in the control circuit designed to acquire and transmit that data.

[0005] For this purpose, the present invention relates to a measuring device comprising a substrate having a receiving portion having an exposed opening in which a sensor is disposed, the substrate including a cavity accommodating a flexible printed circuit, characterized in that the circuit uses a layered bus comprising two data communication buses exposed at two longitudinal ends of the substrate and an internal data acquisition bus, the data acquisition bus linking control circuits together, each control circuit being linked to one of the communication buses, sensors being distributedly linked to the data acquisition bus on both sides of each control circuit, and all sensors between two control circuits transmitting their data to the two control circuits surrounding the sensors.

[0006] In this way, when a control circuit fails, an adjacent control circuit can take over.

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

[0008] Each control circuit includes an elongated housing whose longitudinal direction is orthogonal to the longitudinal direction of the printed circuit.

[0009] The sensor is positioned parallel to the longitudinal direction of the circuit and parallel to the line of the bus.

[0010] The sensor is positioned parallel to the longitudinal direction of the circuit and parallel to the line of the bus.

[0011] The present invention also relates to a measurement system, characterized in that the measurement system includes at least one measuring device having one or more of the features described above, a central unit connected to the measuring device, and at least one end device including line termination impedance.

[0012] The measurement system includes a loopback device, which includes a loopback bus, one end of which is connected to the bus and the other end of which is connected to the bus.

[0013] The measurement system includes an extension device comprising a flexible printed circuit, the flexible printed circuit including a single control circuit connected at one connection end of the circuit to a loopback bus, and a sensor connected to at least one bus, the at least one bus being itself connected to the control circuit.

[0014] The extension device includes two acquisition buses, and the sensor is connected to one or the other of these two buses.

[0015] The loopback bus of the end devices and extension devices is connected to the communication bus of the measurement device via an anisotropic conductive film.

[0016] The present invention also relates to a stationary or moving object having a surface located in a flow path, the object including a measurement system having one or more of the features described above.

[0017] The loop end of the measuring device is installed upstream of the flow in the airflow path surrounding the aircraft.

[0018] The object is an aircraft.

[0019] The present invention also relates to a measurement method comprising a measurement system having one or more of the features described above, characterized in that all sensors connected to a data acquisition bus between two control circuits, respectively referred to as a main circuit and an auxiliary circuit, transmit sensor data to the two circuits via the data acquisition bus, and one of the two circuits, namely the main circuit, transmits data from the sensor to the unit via a communication bus.

[0020] When the unit no longer receives data from the main circuit, it will transfer control to the corresponding auxiliary circuit of the sensor in question.

[0021] The auxiliary circuit monitors the activity of the bus that it is connected to the associated main circuit, and notifies the unit when there is no activity. The unit then requests the auxiliary circuit to transmit data from the sensor to it. Attached Figure Description

[0022] 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:

[0023] [ Figure 1 [This is a partial top view of the aircraft, and the measurement system according to the invention is installed on the wing section of the aircraft;]

[0024] [ 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 links are shown.

[0025] [ Figure 3 [Illustrated diagram of a simplified cross-section of the measuring device according to the system of the present invention;]

[0026] [ Figure 4 [ ] is a simplified top view of the printed circuit of the measuring device according to the present invention;

[0027] [ Figure 5 [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 invention, suitable for mounting on a complex geometry.] Detailed Implementation

[0028] according to Figure 1As an illustrative application, a given region 4 of an aircraft 6 is equipped with a measurement system 2 according to the invention: in the example shown, the system is mounted on a wing section 8. System 2 has several parts, with a third part being optional. The first part includes a device 10 for measuring various physical quantities, which can be mounted on an external surface 12 of the aircraft, and in the example shown above, on the outer surface of the wing section 8 of the aircraft. 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 linked together to form a daisy chain of devices, allowing measurements to be performed over a larger area. A second section terminates the measuring devices 10 via a loopback device 16 or an end device 17. The loopback device 16 provides a link between exposed buses on the substrate, as seen below. The end device 17 terminates the last measuring device 10 in the chain: this end device includes a line termination impedance, allowing the electrical circuit formed by a 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 devices. The loopback device 16, end device 17, or extension device 18 is positioned at the end of the measuring devices. The extension device 18 includes a device capable of measurement like the measuring device 10. However, this extension device does not exhibit 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 the measuring device. The fourth part includes a central unit 19, which powers one or more measuring devices 10 and one or more extension devices 18, and also acquires signals from the one or more measuring devices 10 and the one or more extension devices 18. The power supply and acquisition unit 19 is located inside the aircraft, and in the illustrated example, within the wing section. Unit 19 can consist of a single block or several blocks; as shown in the illustrated form, the unit includes a power supply unit 19A and a separate acquisition unit 19B, linked together. In practice, the power supply unit 19A can be an existing power source for the aircraft. The measurement system 2 sequentially includes the power supply and acquisition unit 19, one or more measuring devices 10' to 10"', one or more loopback devices 16, end devices 17, and / or one or more extension devices 18.

[0029] Figure 3The measuring device 10, shown in cross-section, takes the form of a flexible substrate 20 for sensors 22, allowing the measuring device to conform to the contours of the aircraft 6. Each sensor 22 is designed to measure physical quantities, such as pressure, temperature, acceleration, mechanical force, etc., as illustrative and non-limiting examples. Sensors 22 can be grouped into units that allow the measurement of several quantities, for example, grouped into a microelectromechanical system called a MEMS. In the following sections, the multi-parameter measuring unit of the MEMS type will be referred to as sensor 22. The substrate 20 serves to provide a shield for the sensors, so that the sensors do not require any specific housing, and the substrate also serves to hold the sensors as close as possible to the surface where the measuring device is set for the measurement to be performed. The substrate can be made of a polymer material (e.g., polyurethane or flexible silicone) to conform to the contours of the aircraft. This material also allows for the absorption of thermal stress. The material can be formed by molding, machining, or any other known manufacturing process.

[0030] The substrate 20 can take any given shape. In the example shown, the substrate has an elongated shape with a trapezoidal cross-section. As indicated, the substrate can take another shape. The sensor 22 is housed in the thicker central portion of the substrate. The substrate 20 can accommodate multiple sensors 22. The sensors 22 are distributed uniformly or otherwise along the entire or partial length of the substrate 20. Figure 2 In one embodiment of the invention shown, the sensors 22 are distributed in a uniform manner. Each sensor 22 is separated from its adjacent sensors by a certain distance to avoid any interference between the operation of these sensors. Figure 2 As shown, sensor 22 is arranged, for example, along the same line 23 parallel to the longitudinal direction of the substrate. Figure 3 The accommodating portion 24 shown is disposed in the substrate 20 for receiving the sensor 22: each accommodating portion 24 receives one sensor 22.

[0031] like Figure 3As shown, substrate 20 has a cavity 26 formed in the substrate. Cavity 26 receives a flexible printed circuit 28 (commonly referred to as a flexible PCB (representing a printed circuit board) or flexible circuit). Cavity 26 has a shape corresponding to and conforms to the shape of circuit 28. In the example shown, circuit 28 has an elongated shape that matches the shape of substrate 20. Circuit 28 and substrate 20 are aligned along the same longitudinal direction. In measuring device 2, circuit 28 is housed within a cavity leading to receiving portion 24, into which sensor 22 connected to circuit 28 is inserted. Sensors are distributed on circuit 28. Receiving areas providing connection points are included, to which connection points from sensor 22 to integrated circuit 28 are soldered. The detailed structure of substrate 20 will not be described in further detail as it is not the subject of this patent application. Architectures such as those described in the foregoing patent are known.

[0032] like Figure 2As shown, the flexible printed circuit 28 uses a layered bus, that is, it includes two data communication buses 30, 32 exposed at two longitudinal ends of the substrate 20, and an internal data acquisition bus 34 connected to each sensor 22 of the substrate. Bus 34 links control circuits 36 together, which are distributed between the sensors 22 (or more precisely, between the links of the sensors 22 and the bus 34) and connected to one of the data communication buses 30. The connections of the sensors 22 to the bus 34 are distributed on both sides of each control circuit 36. In this way, the sensors 22 between the two control circuits 36 transmit their data to the two control circuits 36 surrounding these sensors, which will be described in more detail below. In the illustrated embodiment, the connections of the sensors 22 to the bus 34 are evenly distributed, that is, there are the same number of sensor connections on both sides of the circuit 36. In the illustrated embodiment, the buses 30, 32, and 34 are parallel to each other and parallel to the longitudinal direction of the circuit 28. These buses are also parallel to the lines 23 of the sensors 22. Longitudinally, the substrate 20 includes two ends 38, 40. At one end, referred to as daisy-chain end 38, buses 30 and 32 are connected from one substrate to another via any known type of means (e.g., solder wires). At another end, referred to as loop end 40, buses 30 and 32 of the same substrate are connected together via loop device 16, end device 17, or extension device 18. In the case of end device 17, buses 30 and 32 are connected via the line termination impedance. Loop device 16 or extension device 18 connects the ends of the two buses 30 and 32 located longitudinally on the same side at loop end 40. Loop device 16 and extension device 18 each include a bus 42 forming a loop: when device 16 or 18 is attached to measuring device 10, one end of bus 42 contacts the end of bus 30, and the other end contacts the end of bus 32. In the case of only one measuring device 10, or for the first device 10 in a chain of measuring devices 10, the end of bus 30 at daisy-chain end 38 is connected to central unit 19. For other measuring devices, the end of bus 32 on one side of the daisy-chain end 38 is connected to the bus 30 of another measuring device 10. Relative to the daisy-chain end 38, the loop end 40 of the measuring device is installed upstream of the flow in the flow path to be characterized (here, the airflow path around the aircraft). Therefore, there is no connection between upstream substrates that could alter the flow and interfere with the measurement of sensor 22. Connections between measuring devices are made downstream.

[0033] Control circuit 36 ​​receives measurements from all sensors located on either side of each sensor 22. For the first and last control circuits constituting bus 34, and for the two end control circuits 36 positioned as close as possible to each longitudinal end 38, 40 of the substrate in the illustrated embodiment, data from the sensor 22 located between the end 38 or 40 and the corresponding circuit 36 ​​is acquired by only a single circuit 36. For all other circuits 36, data transmitted from the sensor 22 to the bus 34 included between the two circuits 36 is acquired by the two circuits 36 surrounding the sensor. The sensor transmits data from both sides of bus 34 to the two circuits surrounding them. One of these two control circuits 36 is designated as the master circuit because it is responsible for transmitting the data received from the sensor 22 in question to unit 19. The other of these two control circuits 36 is referred to as the auxiliary circuit because it also receives data from the sensor but only transmits the data in the event of a failure of the master circuit. Each master circuit has two monitoring levels. Each control circuit 36 ​​has its own address and identifies itself to the central unit 19 using its address. At the first monitoring level, if the main circuit 36 ​​ceases to respond to unit 19 due to a fault, and if that unit no longer receives any data from the main circuit 36, unit 19 disables the main circuit 36 ​​and requests the adjacent auxiliary circuit 36 ​​to transmit data from the sensors attached to the faulty circuit 36. The auxiliary circuit then takes over and transmits the data received from the sensors in question. At the second monitoring level, the auxiliary control circuit 36 ​​monitors the sensors managed by the corresponding main control circuit 36. If the auxiliary circuit 36 ​​detects no activity on the bus connecting it to the main circuit, it notifies unit 19 of this situation, causing unit 19 to disable the main circuit 36 ​​in the same manner as before and request the auxiliary circuit 36 ​​to transmit data from the sensors attached to the faulty circuit 36. Therefore, in the illustrated embodiment, for all sensors surrounded by two control circuits, the control circuit 36 ​​plays a primary role for all sensors located to its right and a secondary role for all sensors located to its left. Depending on the sensor in question, each control circuit 36 ​​is both a main circuit and an auxiliary circuit. In this way, if one of the circuits 36 fails, the other circuit 36 ​​takes over and provides data communication from the sensors in question. These two monitoring levels allow coverage of all fault levels on the hierarchical bus. The system includes a master-slave architecture, with the central unit as the master and managing the switching of the control circuitry.

[0034] In the illustrated embodiment, control circuitry 36 includes an FPGA (Field Programmable Gate Array) integrated circuit. According to an illustrative embodiment, flexible printed circuitry 28 comprises at least two layers, and in the illustrated example, includes a circuit layer and a ground plane layer. All buses 30, 32, and 34, sensor 22, and circuitry 36 reside on a single layer, namely the circuit layer. Due to this architecture, circuitry 28 is flexible to conform as closely as possible to the shape of an aircraft (such as the leading edge of a wing segment). To further increase its flexibility, the housing of control circuitry 36 is chosen to be elongated, for example, in the shape of a parallelepiped strip with a rectangular cross-section: the housing of control circuitry 36 is mounted on printed circuitry 28 in such a way that the longitudinal direction of circuitry 36 is orthogonal to the longitudinal direction of printed circuitry 28. Figure 4 The control circuit 36 ​​is positioned laterally to the printed circuit 28. In this way, by extending a shorter length longitudinally, the circuit 28 is allowed to have greater flexibility.

[0035] like Figure 4 As shown, all sensors have the same address. An interface component 44 is placed between each sensor 22 and the acquisition bus 34, allowing the sensor address to be modified differently for each sensor in a manner that enables the sensor to be recognized by one or more associated control circuits and the central unit 19. This component can, for example, apply an offset or conversion to the sensor address; the offset is different for each sensor. The control circuit 36 ​​controls the sensors 22 assigned to it, acquires data from these sensors, and transmits the data to the central unit via data communication buses 30 and 32.

[0036] The loopback device can take any possible form. In the illustrated embodiment, the loopback device's bus 42 is connected to the measuring device 10's buses 30 and 32 via an anisotropic conductive film, but it can also be connected in any other possible manner. Because the anisotropic conductive film is rigid, it ensures good mechanical strength while providing conductivity.

[0037] The extension device 18 is nearly identical to device 10, except that it includes a substrate and flexible printed circuit 46, except that circuit 46 includes only a single control circuit 36 ​​and sensors 22 connected to circuit 36 ​​via at least one acquisition bus 48. The control circuit 36 ​​is located at the link end 50, i.e., the end of the circuit is intended to be associated with the measuring device 10. In the same manner as the loopback device, the extension device includes a bus 42 designed to loop bus 30 back to bus 32. The control circuit 36 ​​of the extension device is connected to bus 42 and all sensors 22 via one or more acquisition buses 48, and in the illustrated embodiment, there are two acquisition buses. In the illustrated embodiment, these two acquisition buses 48 are parallel to each other and parallel to the longitudinal direction of circuit 46, and are positioned on either side of the line 23 formed by the sensors. The sensors 22 are connected to one or the other of the buses 48, and in the illustrated embodiment, one sensor is connected to one bus, then an adjacent sensor is connected to another bus, and so on alternately. Because multiple sensors 22 are connected to only a single control circuit 36, the sensors are alternately connected to two buses 48, allowing one of the two sensors to remain in operation should one of these buses fail. Since the circuitry of the extension device consists only of sensors 22 linked together via one or more buses 48, the flexible circuitry can be cut (between the sensors 22) to any given length. Figure 2 and Figure 5 As shown, the strip-shaped control circuit 36 ​​is connected to the measuring device 10, and the width of the printed circuit 46 is smaller than the width of the circuit 28 of the device 10. Therefore, in the illustrated embodiment, the extension device is T-shaped. Due to its greater flexibility, the extension device allows the system to adapt to any geometry. Figure 5 As shown, even on more complex shapes with various surface features, extension devices linked in a daisy-chain configuration can be used. Due to their significantly smaller size and greater flexibility, these extension devices can adapt to any given shaped surface to which the measurement system is applied. The central unit 52 is connected to the control circuitry of the first extension device, and the control circuitry of subsequent extension devices is connected to each other. Unit 52 may be the same as or different from unit 19. The system also operates according to a master-slave architecture: this unit manages the exchange with the control circuitry 36. The control circuitry 36 of each extension device receives measurements obtained by all sensors 22 and sends these measurements to the central unit 19. Each sensor has its own address via interface component 44 and can identify itself to the corresponding control circuitry 36 and unit 52. Each control circuitry 36 has its own address and identifies itself to the central unit 19 using its address.

[0038] This invention is not limited to the field of aviation. The measurement system according to the invention can be used in many other technical fields, such as the field of space vehicles, air vehicles, land vehicles, or marine vehicles. The aircraft is considered an air vehicle. The invention can also be used on stationary objects placed in the flow path of air, 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 measuring devices to one or more walls of the wind tunnel, which is considered a stationary object in the flow path.

Claims

1. A measuring device (10) capable of being fixed to a moving object or a surface of a fixed object located in a flow path, the measuring device comprising a substrate (20) having a receiving portion (24) having an exposed opening in which a sensor (22) is disposed, the substrate (20) comprising a cavity (26) accommodating a first flexible printed circuit (28), characterized in that, The first flexible printed circuit (28) uses a layered bus, which includes two data communication buses (30, 32) exposed at two longitudinal ends of the substrate (20) and an internal data acquisition bus (34) that links multiple control circuits (36) together, each control circuit (36) being linked to one of the data communication buses. The sensors (22) are distributedly connected to the internal data acquisition bus (34) on both sides of each control circuit (36), and all the sensors (22) between two control circuits (36) transmit their data to the two control circuits (36) surrounding the sensors.

2. The measuring device according to claim 1, characterized in that, Each control circuit (36) includes an elongated housing, the longitudinal direction of which is orthogonal to the longitudinal direction of the first flexible printed circuit (28).

3. The measuring device according to any one of claims 1 and 2, characterized in that, The sensor is positioned on a line (23) parallel to the longitudinal direction of the first flexible printed circuit (28) and parallel to the data communication bus (30, 32) and the internal data acquisition bus (34).

4. A measurement system, characterized in that, The measurement system includes at least one measuring device (10) according to any one of claims 1 to 3, a central unit (19) connected to the measuring device, and at least one end device (17) including line termination impedance.

5. The measurement system according to claim 4, characterized in that, The measurement system includes a loopback device (16), which includes a loopback bus (42), one end of which is connected to one of the data communication buses (30), and the other end of which is connected to another data communication bus (32).

6. The measurement system according to claim 5, characterized in that, The measurement system includes an extension device (18) that includes a second flexible printed circuit that includes a single control circuit (36) connected to the loopback bus (42) at one connection end (50) of the second flexible printed circuit, and a sensor (22) connected to at least one acquisition bus (48) of the extension device, the at least one acquisition bus being itself connected to the control circuit (36) of the second flexible printed circuit.

7. The measurement system according to claim 6, characterized in that, The extension device (18) includes two acquisition buses (48), and the sensor (22) is connected to one or the other of the acquisition buses.

8. The measurement system according to any one of claims 6 to 7, characterized in that, The loopback bus (42) of the loopback device (16) and the extension device (18) is connected to the data communication bus (30, 32) of the measuring device (10) via an anisotropic conductive film.

9. A stationary or moving object having a surface located in a flow path, said object being equipped with a measurement system according to any one of claims 4 to 8.

10. The object according to claim 9, characterized in that, The object in question is an aircraft.

11. The object according to claim 10, characterized in that, The loop end (40) of the measuring device (10) is installed upstream of the flow in the airflow path surrounding the aircraft.

12. A measurement method, said measurement method using the measurement system according to any one of claims 4 to 8, characterized in that, All sensors (22) connected to the internal data acquisition bus (34) between the two control circuits (36), which are respectively called the main circuit and the auxiliary circuit, transmit the sensor data to the two control circuits (36) via the internal data acquisition bus (34). The main circuit of the two control circuits transmits the data from the sensor (22) to the central unit (19) via the data communication bus (30, 32).

13. The measurement method according to claim 12, characterized in that, When the central unit (19) no longer receives any data from the main circuit, the central unit transfers control to the corresponding control circuit (36) of the auxiliary circuit referred to as the sensor in question.

14. The measurement method according to any one of claims 12 and 13, characterized in that, The control circuit (36), referred to as the auxiliary circuit, monitors the activity of the internal data acquisition bus connected to the associated main circuit and notifies the central unit (19) if there is no activity. The central unit then requests the auxiliary circuit to transmit data from the sensor in question.

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