AUTOMATIC DETECTION OF A HARDWARE CONFIGURATION OF A DEVICE ON BOARD AN AIRCRAFT

Abstract

A method for detecting a hardware configuration of a device intended to be carried aboard an aircraft turbomachine and controlled by a two-channel protection calculator (8), comprising a power supply able to supply the device, a first measuring box (16) able to measure a first voltage V.sub.s1 at the output of the device and a second measuring box (18) capable of measuring a second voltage V.sub.s2 at the output of the device: a) Send a control voltage to the input of the equipment Vc; b) Measure the first voltage V.sub.s1 and the second voltage V.sub.s2; c) Infer the hardware configuration of the device from the values of the first and second voltages measured V.sub.s1 and V.sub.s2.

Claims

1. A method for detecting a hardware configuration of a device (2) intended to be carried aboard an aircraft turbomachine and controlled by a two-channel protection calculator (8), comprising: a power supply able to supply the device that comprises a control module adapted to send a control voltage to the input of the equipment; a first measuring box (16) able to measure a first voltage (V.sub.s1) at the output of the device; and a second measuring box (18) capable of measuring a second voltage (V.sub.s2) at the output of the device, the method comprising: a) sending a control voltage (Vc) to the input of the device (2); b) measuring the first voltage (V.sub.s1) and the second voltage (V.sub.s2); c) inferring the hardware configuration of the device (2) from the values of the first and second voltages measured (V.sub.s1, V.sub.s2), by means of the calculator, which is adapted to recognize the configuration of the equipment from said first and second measured voltage values.

2. The method according to claim 1, wherein the device is a fuel-metering unit (2, 24, 26) comprising a movable element and having one of the following hardware configurations: a first hardware configuration where the fuel-metering unit (2) comprises a position-measuring unit (20) for the movable element; a second hardware configuration where the fuel metering member (24) does not comprise a position-measuring unit (20), and where a wiring or a harness wiring establishes a short circuit between a control module (14) and the measuring boxes (16, 18) of the protection calculator (8); or a third hardware configuration where the fuel-metering unit (26) does not include a position-measuring unit (20), and where the wiring or harness wiring establishes an open circuit between the control module (14) and the measuring boxes (16, 18) of the protection calculator (8).

3. (canceled)

4. The method according to claim 1, wherein the control voltage (Vc) is sent by the protection calculator (8).

5. The method according to claim 1, wherein the control voltage (Vc) is a DC voltage of less than 15V.

6. The method according to claim 1, wherein the first and second voltages measured (V.sub.s1, V.sub.s2) are each compared with threshold values S.sub.1, S.sub.2 and S.sub.3, such that S.sub.1<S.sub.2<S.sub.3 in particular where S.sub.1 ϵ[0; 0,1×Vc], S.sub.2 ϵ[0,8×Vc; 0,9×Vc] et S.sub.3 ϵ[0,9×Vc; 1,1×Vc], where Vc being is the control voltage.

7. The method according to claim 1, wherein the sum (V.sub.s1+V.sub.s2) of the first and second voltages measured (V.sub.s1, V.sub.s2) is compared with threshold values S.sub.3, S.sub.4 and S.sub.5, such that S.sub.3<S.sub.4<S.sub.5 in particular where S.sub.4 ϵ[0; 0,1×Vc], S.sub.5ϵ[0,9×Vc; 1,1×Vc] et S.sub.6 ϵ[1,8×Vc; 2,2×Vc], where Vc being is the control voltage.

8. A non-transitory computer readable memory storing a calculator program comprising computer-executable instructions for implementing the method of claim 1, when executed on a processor.

9. A protection calculator comprising a processor coupled to a memory such that the calculator program of claim 8 is stored in the memory.

10. The method according to claim 1, wherein the device is a fuel-metering unit (2, 24, 26) comprising a movable element and a first hardware configuration where the fuel-metering unit (2) comprises a position-measuring unit (20) for the movable element.

11. The method according to claim 10, wherein the first and second voltages measured (V.sub.s1, V.sub.s2) are each compared with threshold values S.sub.1, S.sub.2 and S.sub.3, such that S.sub.1<S.sub.2<S.sub.3 in particular where S.sub.1 ϵ[0; 0,1×VC], S.sub.2 ϵ[0,8×Vc; 0,9×Vc] et S.sub.3 ϵ[0,9×Vc; 1,1×Vc], where Vc is the control voltage.

12. The method according to claim 10, wherein the sum (V.sub.s1+V.sub.s2) of the first and second voltages measured (V.sub.s1, V.sub.s2) is compared with threshold values S.sub.3, S.sub.4 and S.sub.5, such that S.sub.3<S.sub.4<S.sub.5 in particular where S.sub.4 ϵ[0; 0,1×Vc], S.sub.5 ϵ[0,9×Vc; 1,1×Vc] et S.sub.6 ϵ[1,8×Vc; 2,2×Vc], where Vc is the control voltage.

13. The method according to claim 1, wherein the device is a fuel-metering unit (2, 24, 26) comprising a movable element and a second hardware configuration where the fuel metering member (24) does not comprise a position-measuring unit (20), and where a wiring or a harness wiring establishes a short circuit between a control module (14) and the measuring boxes (16, 18) of the protection calculator (8).

14. The method according to claim 13, wherein the first and second voltages measured (V.sub.s1, V.sub.s2) are each compared with threshold values S.sub.1, S.sub.2 and S.sub.3, such that S.sub.1<S.sub.2<S.sub.3 in particular where S.sub.1 ϵ[0; 0,1×VC], S.sub.2 ϵ[0,8×Vc; 0,9×Vc] et S.sub.3 ϵ[0,9×Vc; 1,1×Vc], where Vc is the control voltage.

15. The method according to claim 13, wherein the sum (V.sub.s1+V.sub.s2) of the first and second voltages measured (V.sub.s1, V.sub.s2) is compared with threshold values S.sub.3, S.sub.4 and S.sub.5, such that S.sub.3<S.sub.4<S.sub.5 in particular where S.sub.4 ϵ[0; 0,1×Vc], S.sub.5 ϵ[0,9×Vc; 1,1×Vc] et S.sub.6 ϵ[1,8×Vc; 2,2×Vc], where Vc is the control voltage.

16. The method according to claim 1, wherein the device is a fuel-metering unit (2, 24, 26) comprising a movable element and a third hardware configuration where the fuel-metering unit (26) does not include a position-measuring unit (20), and where the wiring or harness wiring establishes an open circuit between the control module (14) and the measuring boxes (16, 18) of the protection calculator (8).

17. The method according to claim 16, wherein the first and second voltages measured (V.sub.s1, V.sub.s2) are each compared with threshold values S.sub.1, S.sub.2 and S.sub.3, such that S.sub.1<S.sub.2<S.sub.3 in particular where S.sub.1 ϵ[0; 0,1×VC], S.sub.2 ϵ[0,8×Vc; 0,9×Vc] et S.sub.3 ϵ[0,9×Vc; 1,1×Vc], where Vc is the control voltage.

18. The method according to claim 16, wherein the sum (V.sub.s1+V.sub.s2) of the first and second voltages measured (V.sub.s1, V.sub.s2) is compared with threshold values S.sub.3, S.sub.4 and S.sub.5, such that S.sub.3<S.sub.4<S.sub.5 in particular where S.sub.4 ϵ[0; 0,1×VC], S.sub.5 ϵ[0,9×Vc; 1,1×Vc] et S.sub.6 ϵ[1,8×Vc; 2,2×Vc], where Vc is the control voltage.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0030] FIG. 1 shows a first configuration of a fuel-metering unit;

[0031] FIG. 2 shows a first configuration of a fuel-metering unit;

[0032] FIG. 3 shows a first configuration of a fuel-metering unit.

DETAILED DESCRIPTION OF THE INVENTION

[0033] During maintenance operations, the replacement of a fuel-metering unit (FMU) does not necessarily imply an identical replacement, so that a fuel-metering unit with a first hardware configuration can be replaced by a metering unit with a second hardware configuration.

[0034] Three models of fuel-metering units are currently in use, each with its own hardware configuration as shown in FIGS. 1, 2 and 3 respectively.

[0035] As can be seen, in the turbomachine, the fuel-metering units 2 are connected via two separate harnesses 4, 6 to a two-channel protection calculator 8. This protection calculatorcalculator 8 actually comprises two independent calculators 10, 12, one main and one secondary, communicating with each other and performing the same operations/calculations. This calculator redundancy is particularly necessary in the event of a malfunction of the main calculator 10: the latter is then isolated and the secondary calculator 12 then becomes the calculator in charge of controlling the equipment, particularly the fuel-metering units 2.

[0036] Each of the protection calculators 10, 12 comprises: [0037] a control module 14, able to send control voltages Vc to the various devices 2 under the supervision of the protection calculator 8. This control voltage, specific to each device, is thus able to supply the target device 2. [0038] a first 16 and a second 18 measuring box, suitable for measuring voltages V.sub.s1 and V.sub.2 emitted at the output of the devices in response to a control voltage sent by the control module 14. Also, although not shown in FIGS. 1 to 3, the calculator calculatorcomprises a processor coupled to a memory, capable of performing calculations to control the various devices supervised by the protection calculatorcalculator.

[0039] The first hardware configuration of the first model of fuel-metering unit 2 is characterised by the presence of a passive electrical sensor 20, which makes it possible to obtain the position of the fuel-metering unit. This sensor is usually an LVDT (Linear Variable Differential Transformer) sensor, and is also redundant, so that the first LVDT sensor 20 is connected to the first calculatorcalculator 10 and the second LVDT sensor 22 is connected to the second calculatorcalculator 12.

[0040] Thus, in response to a supply voltage from the control modules 14 of the first and second channels 10, 12 (i.e. the first and second calculators), the voltages V.sub.s1 and V.sub.s2 at the output of the LVDT sensors 20, 22 are measured on the two channels 10, 12 respectively.

[0041] This first model is usually called the Cutback FMU.

[0042] The second hardware configuration of the second fuel-metering unit model 24 differs from the first hardware configuration of the first model in that there is no LVDT. Therefore, in contrast to the first configuration, the calculator 8 does not receive any feedback from an LVDT. Indeed, as can be seen in FIG. 2, the output voltage of the power supply unit of the control module is equal to the output voltage of the fuel-metering unit. In other words, a deliberate short circuit is implemented on both channels of the protection calculator 10, 12. The terminals of the control module 14 are directly connected to the terminals of the measuring boxes 16, 18. The short circuit is implemented either at the level of the harness 4 or directly at the level of the device, i.e. the fuel-metering unit 24. Thus, the second hardware configuration is one where the fuel-metering unit 24 does not include a position-measuring unit 20, and its wiring or the wiring of the harness establishes a short circuit between the control module 14 and the measuring boxes 16, 18, of the two-channel protection calculator 8.

[0043] The third hardware configuration of the third fuel-metering unit model 26, like the second configuration, does not include an LVDT. The third hardware configuration 26 differs from the second hardware configuration in that a voluntary open circuit is created on both channels 10, 12. Indeed, as can be seen in FIG. 3, given the absence of the LVDT, the calculator 8 no longer receives a signal from an LVDT sensor. Furthermore, in contrast to the second configuration 24, the control module 14 is connected to a first 28 and second 30 terminals of the fuel-metering unit 26 isolated from each other so as to form an open circuit. The two-channel measuring boxes 10, 12 are not connected to the control module 14, but to third 32, fourth 34 and fifth 36 terminals which are isolated from each other or alternatively connected to a common ground. This third design 26, generally referred to as the Baseline, is characterised by a fuel-metering unit 24 which does not include a position-measuring unit. In addition, its wiring or the wiring of the harness of this third model 26 establishes an open circuit between the control module 14 and the measuring boxes 16, 18 of the two-channel protection calculator 8.

[0044] The method of detecting the model of the fuel-metering unit used is based primarily on the voltages measured by the measuring boxes under a 7V DC supply to the fuel-metering unit.

[0045] It is implemented as a calculator program comprising instructions for implementing this detection process when executed on a processor. In particular, it is stored in the memory of the calculator coupled to the processor, so that it can be executed by the protection calculator.

[0046] In this way, the detection of the hardware configuration of the fuel-metering units connected to the protection calculator is automatic.

[0047] The detection method consists, in a first step, in sending a control voltage to the input of the equipment, i.e. the fuel-metering unit 2, 24, 26 Vc. This control voltage Vc is a DC voltage equal to 7 V.

[0048] In a second step, the measuring boxes 16, 18, measure the first and second secondary voltages V.sub.s1 and the second secondary voltage V.sub.s2 at the output of the fuel-metering unit 2, 24, 26.

[0049] Depending on the voltages measured V.sub.s1 and V.sub.s2 the hardware configuration of the fuel-metering unit 2, 24, 26, i.e. the model used, is inferred. Indeed, the hardware configurations presented above are characterised by the following voltage values:

TABLE-US-00001 TABLE 1 Hardware configuration of the metering unit Configuration 1 Configuration 2 Configuration 3 V.sub.S1 or V.sub.S2 <6V  <7V <0V V.sub.S1 + V.sub.S2 <7V <14V <0V

[0050] Thus, the first configuration of the fuel-metering unit 2, comprising an LVDT sensor 20, whose output signal is measured, is characterised by voltages measured V.sub.S1 and V.sub.S2 such that V.sub.S1<6V and V.sub.S2<6V and V.sub.S1+V.sub.S2˜7V.

[0051] The second configuration of the fuel element 24, which does not include an LVDT, is characterised by voltages measured V.sub.S1 and V.sub.S2 such that V.sub.S1˜7V and V.sub.S2˜7V and V.sub.S1+V.sub.S2˜14V. Indeed, due to the voluntary short circuit, the voltages V.sub.S1 and V.sub.S2 are both approximately equal to the DC voltage delivered by the control module, i.e. a DC voltage of 7V.

[0052] The second configuration of the fuel element 26, which does not include an LVDT, is characterised by voltages measured V.sub.S1 and V.sub.S2 such that V.sub.S1˜0V and V.sub.S2˜0V and V.sub.S1 V.sub.S2˜0V. Indeed, due to the voluntary open circuit, the voltages V.sub.S1 and V.sub.S2 are both approximately zero.

[0053] As a result, the voltages V.sub.S1 and V.sub.S2 are compared to the threshold values S.sub.1, S.sub.2 and S.sub.3 with the following values 0V, 6V and 7V respectively. Alternatively, or additionally, the sum of the voltages measured is compared with the threshold values S.sub.3, S.sub.4 and S.sub.5 with the following values respectively: 0V, 7V and 14V.

[0054] In general, the values of the thresholds can be in the following ranges respectively: [0055] S.sub.1 ϵ[0; 0,1×Vc], S.sub.2 ϵ[0,8×Vc; 0,9×Vc] et S.sub.3 ϵ[0,9×Vc; 1,1×Vc], [0056] S.sub.4 ϵ[0; 0,1×VC], S.sub.5 ϵ[0,9×Vc; 1,1×Vc] et S.sub.6 ϵ[1,8×Vc; 2,2×Vc].

[0057] Preferably, all the steps of this method are carried out by the protection calculator when the aircraft's devices are switched on.