FR3044403A1 - MONOCABLE ELECTRONIC SENSOR AND TREATMENT UNIT THEREFOR - Google Patents

Abstract

An electronic sensor (2) intended to be integrated into an electronic system (1) of an aircraft, comprising means (7) for measuring an environmental parameter of the aircraft capable of delivering a measurement signal, a circuit for transmission (8) of the measurement coupled to the measuring means (7) and a sensor supply circuit (9). The electronic sensor comprises a single external connection terminal (10) connected to the transmission circuit (8) of the measurement and to the supply circuit of the sensor (9), the external connection terminal (10) being configured for both receiving the power supply current of the sensor (2) and transmitting said measurement signal when a single cable (4) coupled to a corresponding processing unit (3) is connected to the external connection terminal (10).

Description

BACKGROUND OF THE INVENTION The invention relates to an electronic sensor of an electronic system on board an aircraft, and more particularly to a single-cable electrical sensor for measuring physical quantities characterizing the environment and / or the operation of the aircraft. aircraft or a system of the aircraft.

For example, the regulation of aircraft engines increasingly uses measurements of operating conditions of the aircraft. The introduction of health monitoring systems, or "Health Monitoring" in English, further increases the need for additional measures.

These additional measures involve the installation of new sensors and additional connections to power these new sensors and deliver their measurement data to the acquisition systems.

The cost of a new measure is not negligible in terms of financial cost, in terms of mass, in terms of installation, and in terms of electronic management. Indeed, the installation of new sensors is often made difficult because of the constraints of installation and connection of these sensors to the acquisition system of the aircraft which is necessarily centralized.

OBJECT AND SUMMARY OF THE INVENTION The aim of the invention is to overcome the above drawbacks by proposing an electronic sensor and an associated processing unit configured to simplify the installation of these electronic elements by reducing the number of necessary connections to its bare minimum. .

An object of the invention proposes an electronic sensor intended to be integrated in an electronic system of an aircraft, the electronic sensor comprising means for measuring an environmental or operating parameter of the aircraft, or a system for the aircraft, capable of delivering a measurement signal, a transmission circuit of the measurement coupled to the measuring means and a sensor supply circuit.

By environmental parameter, one understands as well a parameter external to the system such as the temperature of an interior part or of an external part of the aircraft or the electronic system, a parameter directly dependent on the electronic system such as the state of the electrical connection of an electronic component of the electronic system to the supply network. By operating parameter is meant any parameter making it possible to characterize a state of operation of the system such as in the case of an engine: a speed, a temperature of the combustion chamber, a turbine, the pressure of the combustion chamber .

According to a general characteristic of the invention, the electronic sensor comprises a single external connection terminal connected to the transmission circuit of the measurement and to the supply circuit of the sensor, the external connection terminal being configured to both receive the current supplying power to the sensor and transmitting said measurement signal when a single cable coupled to a corresponding processing unit is connected to the external connection terminal

By thus using the electrical cable carrying the electrical supply signal of the electronic sensor as the transmission cable of the measurement signal, the cost, the mass and the space requirement of the power supply and power return cables are saved.

According to a first aspect of the electronic sensor, the sensor may comprise a casing comprising at least one conductive part intended to be connected to a mass.

The known sensors onboard an aircraft do not use mass feedback via the crankcase. Indeed, the mass feedback of the known sensors generally passes through a dedicated wire in the cable connecting the sensor to a processing unit. This choice, the use of a dedicated wire for the return, is explained by the unreliability of the return by the mass because of the disturbances that the signal can undergo via the mass.

Due to the loss of reliability of the measurement compared to a return by a dedicated wire, the electronic sensor according to the invention is thus intended more particularly for applications that do not require a very high reliability of the measurement.

By using a return to ground, that is to say by closing the circuit loop of the measurement signal, via the sensor housing coupled to the carcass of the aircraft to which is connected the mass of the unit of treatment, the electronic system is exempted from an additional electric cable which reduces the financial cost and the total mass of material to board the aircraft.

In addition, there is a guarantee on certified aeronautical equipment that this return by mass is always possible: it is about the constraints of "bounding" guaranteeing that there is always an electrical path between all the points of the aircraft. This requirement stems from a requirement of non-sensitivity to lightning strikes on board equipment.

According to a second aspect of the electronic sensor, the measurement transmission circuit comprises an electronic means for converting the analog measurement signal into an alternating signal, such as a voltage controlled oscillator or VCO in English for "Voltage Controlled Oscillator", coupled to said connection terminal.

There is a whole set of measuring sensors for monitoring the condition of the motor. These sensors usually generate a continuous signal that can not be mixed as it is with an AC power signal.

By design, however, some sensors provide an alternative signal: Linear Variable Differential Transformer (LVDT), Rotary Variable Differential Transformer (RVDT), resolver-type rotary electrical transformers, variable reluctance sensors, and vibration sensors. However, even in this case, the power source is generally separate from the measurement signal, the sensor having two separate connection terminals. Other sensors already incorporate a conversion electronics, such as for example the differential pressure sensor of an oil filter on the CFM56-7B series of turbojets that converts a strain gauge type measurement into an LVDT type signal. This architecture however does not perform any superposition of the measurement signal with the sensor supply.

According to a third aspect of the electronic sensor, the conversion means may comprise an identification module adapted to include a digital identification code of the sensor to the digitally converted measurement signal before its emission from the sensor. The inclusion of a digital identification code in the AC signal thus makes it possible to differentiate the measurement signals from different measuring sensors connected to the same processing unit via the same cable.

According to a fourth aspect of the electronic sensor, the conversion means may further comprise an error correction module able to introduce an error correction code into the digitally converted measurement signal before it is sent out of the sensor.

The error correction module thus makes it possible to immunize the electronic system comprising the electronic sensor and the processing unit associated with its electromagnetic environment.

The correction module may be an electronic device for detecting and correcting errors, in particular using a parity bit, or a cyclic redundancy check (CRC) in English for "Cyclic Redundancy Check", or else procedures for avoiding errors. data collision such as the so-called CSMA / CA access method for "Carrier Sense Multiple Access with Collision Avoidance".

According to a fifth aspect of the electronic sensor, it may further comprise a Pelletier effect module capable of locally cooling said conversion means so as to withstand the different operating temperatures of the sensor.

Another object of the invention proposes a data processing unit coupled to at least one electronic sensor as defined above via at least one electric cable and electrically connected to the same ground as said electronic sensor.

According to a general characteristic of the invention, the processing unit comprises means for determining the value of the measurement able to determine a numerical value relative to the data measured by the sensor from the received alternative data signal.

According to a first aspect of the processing unit, the determining means comprises an analog / digital conversion module.

In a second aspect of the processing unit, the processing unit is configured to be coupled by the same monocable to at least two electronic sensors as defined above.

Another object of the invention proposes an electronic measurement system comprising at least one electronic sensor as defined above and at least one processing unit as defined above.

Yet another object of the invention proposes an aircraft comprising an electronic measurement system as defined above.

Brief description of the drawings. The invention will be better understood on reading the following, by way of indication but not limitation, with reference to the accompanying drawing in which the single figure is a schematic representation of an electronic system according to one embodiment of the invention.

Detailed description of embodiments

FIG. 1 is a diagrammatic representation of an electronic system 1 intended to be carried on board an aircraft, in particular for monitoring the state of health of the aircraft, according to one embodiment of the invention.

The electronic system 1 comprises an electronic sensor 2 and a processing unit 3 connected to the electronic sensor 2 by a single electrical cable 4 included in an electrical harness forming part of the electrical system of the aircraft.

The electronic sensor 2 comprises a casing 5 comprising at least one conductive part connected to a ground 6, a measurement means 7 of a physical parameter of the aircraft, such as an environmental or operating parameter of the aircraft, arranged inside the housing 5 and able to deliver a measurement signal, a measuring transmission circuit 8, a supply circuit 9, and an external connection terminal 10.

The external connection terminal 10 is connected to the transmission circuit 8 of the measurement and to the supply circuit 9 of the sensor 2, and is configured to both receive the power supply current of the sensor 2 and transmit said measurement signal via the cable 4 connecting the processing unit 3 to the external connection terminal 10.

The electronic sensor 2 thus comprises a single connection terminal 10 coupled to a single cable 4 to receive the supply of the electronic sensor 2 and transmit the measurement signal.

The measuring transmission circuit 8 comprises a voltage amplifier 11 and a voltage controlled oscillator 12, or VCO in English for "Voltage Controlled Oscillator". The voltage amplifier 11 amplifies the analog measurement signal and then the voltage controlled oscillator 12 converts the amplified continuous analog measurement signal into an alternating signal.

The alternating measurement signal thus converted is delivered to the external connection terminal 10 to be transmitted to the processing unit 3 via the cable 4.

To close the transmission loop comprising the electronic sensor 2, the cable 4 and the processing unit 3, the ground of the processing unit 3 is coupled to the same ground 6 as the housing 5 of the electronic sensor 2. The mass 6 is formed by the metal carcass A of the aircraft and / or any ground braids in the case where the carcass comprises non-conductive portions. This looping by the mass of the aircraft thus allows to exempt an additional electric cable and thus reduce the financial cost and the total mass of material to board the aircraft.

In the illustrated embodiment, the voltage controlled oscillator 12 comprises an identification module 13 and an error correction module 14.

The identification module 13 is configured to include a digital identification code in the converted AC signal. The digital identification code is specific to the electronic sensor 2. Thus, a processing unit 3 receiving measurement signals from several different electronic sensors 2 via the same cable, such as cable 4 for example, can discriminate the signals and know their signal. from the associated identification numeric code.

The error correction module 14 is configured to input an error correction code into the digitally converted measurement signal before the converted AC signal is transmitted by the electronic sensor 2 to the processing unit 3 via the terminal. 10 and the cable 4.

The error correction module 14 may be an electronic device for detecting and correcting errors, in particular using a parity bit, or a cyclic redundancy check, CRC in English for "Cyclic Redundancy Check", or else procedures avoidance of data collision, such as the so-called CSMA / CA access method for "Carrier Sense Multiple Access with Collision Avoidance".

The error correction module 14 immunizes the electronic system 1 of its electromagnetic environment.

In the illustrated embodiment, the electronic sensor 2 further comprises a Pelletier effect module 15 disposed around the voltage-controlled oscillator 12. The Peletier effect module 15 is configured to locally cool the voltage-controlled oscillator 12 of FIG. in order to resist the different operating temperatures of the electronic sensor 2. The data processing unit 3 to which the electronic sensor 2 is coupled comprises determining means 16 configured to determine a numerical value relative to the data measured by the sensor 2 to from the received alternative data signal.

To determine the digital value of the measurement signal transmitted by the sensor 2 to the processing unit 3, the determination means 16 comprises an analog / digital conversion module 17.

In a variant, the determination means 16 may comprise an AC / DC conversion means or a calculation means able to determine from the frequency of the AC measurement signal emitted by the electronic sensor 2 the corresponding voltage and thus the measurement associated with the value of the voltage. The invention thus provides an electronic sensor and an associated processing unit configured to simplify the installation of these electronic elements by reducing the number of necessary connections to a bare minimum.

Claims (11)

An electronic sensor (2) intended to be integrated with an electronic system (1) of an aircraft, comprising means for measuring (7) an environmental parameter of the aircraft capable of delivering a measurement signal, a circuit for transmitting (8) the measurement coupled to the measuring means (7) and a sensor supplying circuit (9), characterized in that it comprises a single external connection terminal (10) connected to the transmission circuit ( 8) of the measurement and to the supply circuit of the sensor (9), the external connection terminal (10) being configured to both receive the power supply current of the sensor (2) and transmit said measurement signal when a single cable (4) coupled to a processing unit (3) is connected to the external connection terminal (10). 2. Electronic sensor (2) according to claim 1, comprising a housing (5) having at least one conductive portion to be connected to a mass (6). 3. Electronic sensor (2) according to one of claims 1 or 2, wherein the transmission circuit (8) of the measurement comprises an electronic means for converting (12) the analog measurement signal into an output-coupled alternating signal. at said connection terminal (10). An electronic sensor (2) according to claim 3, wherein the electronic conversion means (12) comprises an identification module (13) adapted to include a digital identification code of the sensor (2) to the converted measurement signal. numerically before being transmitted out of the sensor (2). 5. Electronic sensor (2) according to one of claims 3 or 4, wherein the electronic conversion means (12) further comprises an error correction module (14) adapted to introduce an error correction code in the measurement signal converted numerically before being transmitted out of the sensor (2). 6. Electronic sensor (2) according to one of claims 3 to 5, further comprising a Pelletier effect module (15) adapted to locally cool said conversion means (12). Data processing unit (3) coupled to at least one electronic sensor (2) according to one of claims 1 to 6 via at least one electric cable (4) and electrically connected to the same ground (6) as said electronic sensor (2), characterized in that it comprises means (16) for determining the value of the measurement and capable of determining a digital value relative to the data measured by the sensor (2) from the received alternative data signal . Data processing unit (3) according to claim 7, wherein the determining means (15) comprises an analog / digital conversion module (17). 9. Data processing unit (3) according to one of claims 7 or 8, configured to be coupled to at least two electronic sensors (2) according to one of claims 1 to 6 by the same monocable (4). 10. Electronic measuring system (1) comprising at least one electronic sensor (2) according to one of claims 1 to 6 and at least one processing unit (3) according to one of claims 7 to 9. Aircraft comprising an electronic measuring system (1) according to claim 10.