Aircraft flight trim control system

Abstract

System (1) for managing a flight trim tab of an aircraft (100), the system (1) comprising at least one three-phase electric motor (2) for moving the flight trim tab in operation and the system (1) comprising at least one electrical power supply circuit (3) for said motor (2), the circuit (3) comprising several blocks, including at least: a first block (4) arranged to dissipate electrical energy that may be generated by the motor, a second block (10) arranged to impose a given electrical voltage across the motor terminals, a third block (18) comprising the motor, a fourth block (19) for stabilizing the electrical voltage; the system being characterized in that the fourth block (19) is arranged between the first block (4) and the second block (10), the fourth block comprising at least one two-quadrant current-reversible electrical power converter (30). ABRIDGED FIGURE: Fig. 2

Description

Title of the invention: Aircraft flight trim control system

[0001] The present invention relates to the field of flight compensators.

[0002] BACKGROUND OF THE INVENTION

[0003] A flight trim system, more commonly known as a "trim," is a device used to adjust the positioning of one or more control surfaces of an aircraft (such as a rudder) to help maintain the aircraft's balance in flight. A flight trim system automatically adjusts the positioning of one or more control surfaces, thereby reducing the pilot's workload and maintaining a stable flight attitude without requiring constant manual corrections by the pilot. Typically, a flight trim system includes an electric motor that acts on the positioning of one or more control surfaces.

[0004] A distinction is also made between active and passive flight trimmers. Active flight trimmers are traditionally integrated into a complex flight control system that allows a force law to be programmed in order to generate haptic feedback to the pilot. To provide realistic force feedback to the pilot, flight control systems generally include one or more motors and an electrical power supply circuit for said motor. The motor(s) apply at least one torque to at least one control element manipulated by the pilot during operation to act on the same control surfaces.

[0005] However, the flight trimmer can be driven by an external force (for example by the pilot himself): the electric motor then acts as a generator.

[0006] For safety reasons, the electrical power supply circuit of said motor therefore generally includes at least one electrical component for dissipating any electrical energy that may be generated by the motor. The electrical power supply circuit also includes an inverter arranged to apply an electrical voltage across the motor terminals in order to control its torque.

[0007] However, the dissipation of electrical energy is generally accompanied by a rise in voltage across the inverter terminals. This rise significantly degrades the quality of the control of the voltage injected into the motor by the inverter and, consequently, significantly degrades the control of the motor torque.

[0008] However, this degradation of engine torque control is generally perceptible to the pilot, which is detrimental.

[0009] SUBJECT OF THE INVENTION

[0010] The invention aims in particular to improve haptic feedback generated by an active flight trimmer, haptic feedback felt by the pilot. Summary of the invention

[0011] To this end, the invention provides a system for managing a flight trimmer of an aircraft, the system comprising at least one three-phase electric motor intended to move the flight trimmer in operation, the system comprising at least one electrical power supply circuit for said motor, the circuit comprising several blocks of which at least: - a first block arranged to dissipate electrical energy that may be generated by the motor, - a second block arranged to impose a given electrical voltage across the motor terminals, - a third block containing the engine, - a fourth electrical voltage stabilization block across the terminals of at least one of the first, second or third block;

[0012] According to the invention, the fourth block is arranged between the first block and the second block, the fourth block comprising at least one current reversible two-quadrant electrical power converter.

[0013] The inventors were able to observe that, surprisingly, the successive arrangement of the first block and the fourth block ensured a stabilization of the electrical voltage across the terminals of the second block, regardless of the operating modes of the electric motor, even when the electric motor was operating as a generator.

[0014] Furthermore, the inventors were also able to observe that the two-quadrant electrical power converter, reversible in current, also worked to maintain a stable electrical voltage regardless of the operating modes of the electric motor.

[0015] As a result, the quality of the control of the voltage injected into the motor by the second block proves to be much more constant and consequently the control of the motor torque as well.

[0016] Haptic feedback associated with the invention and provided to the pilot therefore proves to be of better quality.

[0017] According to optional features, used individually or in whole or in part in combination: - the circuit successively comprises the first block, the fourth block, the second block and the third block, each block being electrically connected to the block or two blocks immediately adjacent to it; - the first block includes a branch comprising successively a first transistor and a resistor, a first diode being mounted in parallel with the first transistor and a second diode being mounted in parallel with the resistor, the first block comprising an input diode mounted in series with the branch; - the converter is a step-up / step-down chopper for electrical voltage; - the converter includes a first branch comprising two transistors connected in series, and a diode mounted in parallel with each transistor, as well as a second branch connected to the first branch between the two transistors, the second branch comprising an inductance; - the second block includes a power inverter; - the second block comprises a first branch, a second branch, a third branch and a fourth branch, the first, second, third and fourth branches being mounted in parallel with each other, the first branch having a capacitor and the second, third and fourth branches having a pair of transistors mounted in series, a diode being mounted in parallel on each transistor; - the motor is a three-phase brushless electric motor with permanent magnets; - the system includes a processing unit arranged to control at least the second block.

[0018] The invention also relates to an aircraft comprising such a system.

[0019] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

[0020] Reference will be made to the attached drawings, among which:

[0021] [Fig-1] [Fig.1] represents a front view of an aircraft comprising a system management of a flight compensator according to a particular embodiment of the invention;

[0022] [Fig.2] [Fig.2] represents a power supply circuit of the management system the aircraft illustrated in [Fig.1];

[0023] [Fig.3] [Fig.3] represents an electrical diagram of a two-quadrant converter belonging to the power supply circuit illustrated in [Fig.2]. DETAILED DESCRIPTION OF THE INVENTION

[0024] Figure 1 shows an aircraft 100 according to a particular embodiment of the invention. This aircraft 100 includes a system 1 for managing a flight trim tab of said aircraft 100.

[0025] With reference to [Fig. 2], system 1 comprises a three-phase electric motor 2. In this case, the electric motor 2 is a three-phase brushless motor, for example, a three-phase permanent magnet brushless motor. Motor 2 thus combines the advantages of a DC motor and a permanent magnet synchronous motor. Electric motor 2 therefore comprises a first phase 24, a second phase 25, and a third phase 26.

[0026] The electric motor 2 is arranged to move the flight trimmer during operation. Therefore, an output shaft 200 of the electric motor 2 is mechanically linked to the flight trimmer. Consequently, when the electric motor 2 is energized, the shaft 200 pivots, thus enabling the movement of the flight trimmer.

[0027] The system 1 also includes at least one electrical power supply circuit 3 for said motor 2. In the present case, the power supply circuit 3 comprises a plurality of blocks.

[0028] A continuous input voltage Vinput is delivered to the power supply circuit 3 by a power supply source of the aircraft 100. The power supply circuit 3 has two input terminals 27 with the voltage Vinput between these two terminals 27.

[0029] The power supply circuit 3 comprises at least a first block 4, a second block 10, a third block 18 and a fourth block 19.

[0030] The first block 4 includes, for example, an input branch 28, the first end of which is connected to the first input terminal 27 of the power supply circuit 3. The input branch 28 also includes an input diode 9.

[0031] The first block 4 also includes here a branch 29 comprising successively a first transistor 5 and a resistor 6. Said branch 29 is connected on one side to the input branch 28, downstream of the input diode 9, and on the other side to the second input terminal 27 of the power supply circuit 3. The input diode 9 is conducting for one direction of the electric current going from the first input terminal 27 to said branch 29 and said branch 28.

[0032] The first block 4 preferably includes a first diode 7 connected in parallel with the first transistor 5. Thus, one end of the first diode 7 is connected to a point on the branch 29 located between the transistor 5 and the resistor 6. The second end of the first diode 7 is connected to the branch 29 at a point located between the resistor 6 and the junction point of the branch 29 to the input branch 28. The first diode 7 is forward-biased for one direction of electric current going from its first end to its second end.

[0033] The first block 4 preferably includes a second diode 8 connected in parallel with the resistor 6. Thus, one end of the second diode 8 is connected to branch 29 at a point located between transistor 5 and the junction point of branch 29 at the second input terminal 27. Here, the second end of the The second diode 8 is connected to a point on branch 29 located between transistor 5 and resistor 6. The second diode 8 is conducting for one direction of electric current going from its first end to its second end.

[0034] The first block 4 is thus arranged to be able to dissipate electrical energy that may be generated by the motor 2. This avoids the reinjection of electrical energy towards the power source, which can be dangerous and is generally prohibited by aeronautical standards.

[0035] The first block 4 also advantageously protects the electrical power supply circuit 3 from overvoltages and reverse polarity as will be detailed below.

[0036] The fourth block 19 extends beyond the first block 4. To this end, the fourth block 19 includes a capacitor 23, the capacitor 23 being arranged on one side between the input branch 28 (downstream of the first block 4 and therefore downstream of the input diode 9 and the branch 29) and on the other side the second input terminal 27 of the electrical power supply circuit 3. The capacitor 23 is therefore connected in parallel with the branch 29.

[0037] Furthermore, the fourth block 19 includes at least one DC / DC power converter 30, more commonly referred to as a DC / DC converter. This converter 30 is more specifically a two-quadrant, current-reversible DC / DC power converter. Preferably, the converter is a buck-boost converter. The converter has two input terminals, one of which is connected to a second end of the input branch 28 (i.e., downstream of a branch including the capacitor 23), and the other of which is connected to the second input terminal 27 of the power supply circuit 3.

[0038] With reference to [Fig. 3], the fourth block 19 comprises a first branch 20 having at least two transistors T1, T2 connected in series. The first branch 20 has a first end connected to the first input terminal of the converter 30 and a second end connected to the second input terminal of the converter. The first branch 20 is therefore connected in parallel with the branch 29 and / or the capacitor 23.

[0039] Furthermore, a diode DI is connected here in parallel with the transistor TL. Thus, one end of the diode DI is connected to a point on the first branch 20 located between the two transistors T1 and T2. The second end of the diode DI is connected to the first branch 20 at a point located between the transistor T1 and the junction point of the first branch 20 at the first input terminal of the converter 30. The DI diode is forward-biased for one direction of electric current going from its first end to its second end.

[0040] Furthermore, a diode D2 is connected in parallel with transistor T2. One end of diode D2 is connected to the first branch 20 at a point located between transistor T2 and the junction point of the first branch 20 to the second input terminal of converter 30. The other end of diode D2 is connected to a point on the first branch 20 located between the two transistors T1 and T2. Diode D2 conducts in one direction for the electric current flowing from its first end to its second end.

[0041] Furthermore, the converter 30 also includes a second branch 21, the first end of which is connected to the first branch 20. The second branch 21 is connected to the first branch 20 at a point located between the two transistors T1 and T2, and more precisely here at a point located between the first end of diode D1 and the second end of diode D2. Possibly, the second branch 21 is connected to the first branch 20 at a midpoint of the first branch 20. The second branch 21 includes an inductor 22. The second end of the second branch 21 forms a first output terminal of the converter 30.

[0042] Furthermore, the converter 30 also includes here a third branch 31, the first end of which is connected to the second input terminal of the converter 30. The second end of the third branch 31 forms a second output terminal of the converter 30.

[0043] The fourth block 19 is thus arranged to stabilize an electrical voltage across the terminals of at least one of the first block 4, the second block 10 or the third block 18. In the present case, the fourth block 19 is arranged to stabilize the electrical voltage throughout the entire electrical supply circuit 3.

[0044] In particular, the fourth block 19 makes it possible to overcome possible variations in the input voltage which can be significant from one aircraft to another.

[0045] The advantage of having a stabilized voltage lies in the fact that:

[0046] - the dimensioning of at least one of the other three blocks 4, 10 or 18 is simplified; and / or

[0047] - the control of the voltage applied to motor 2 is of better quality.

[0048] The fourth block 19 also allows, in a very advantageous way, the delivery of a voltage between its two output terminals which remains constant (or almost constant) regardless of the direction of the current flowing in the converter 30. The reversibility in current in the electrical supply circuit 3 is therefore ensured by the fourth block 19.

[0049] The second block 10 comprises a DC / AC power converter. For example, said converter is a power inverter or a DC / AC converter.

[0050] A continuous input voltage Vonduieur is delivered to the inverter by the converter 30 of the fourth block 19, said voltage extending between the two output terminals of said converter 30.

[0051] The inverter comprises a first branch 11, a second branch 12, a third branch 13, and a fourth branch 14. The first 11, second 12, third 13, and fourth 14 branches are connected in parallel with each other. In particular, each first end of each of said branches 11, 12, 13, and 14 is connected to the first output terminal of the converter 30, and each second end of each of said branches 11, 12, 13, and 14 is connected to the second output terminal of the converter 30. Consequently, the voltage VonduieUr can be measured across each of the first 11, second 12, third 13, and fourth 14 branches.

[0052] The first branch 11 includes a capacitor 15.

[0053] The second branch 12 comprises at least one pair of transistors 16, the transistors 16 being connected in series. In addition, the second branch 12 comprises at least two diodes, a diode 17 being connected in parallel with each of the transistors 16.

[0054] Thus, a first end of a first of the two diodes 17 is here connected to a point of the second branch 12 located between the two transistors 16. Here, the second end of said diode 17 is connected to the second branch 12 at a point located between a first of the two transistors 16 and the first end of the second branch 12. Said diode 17 is conducting for one direction of the electric current going from its first end to its second end.

[0055] Thus, a first end of a second of the two diodes 17 is here connected to the second branch 12 at a point located between a second of the two transistors 16 and the second end of the second branch 12. Here, the second end of said second diode 17 is connected to a point of the second branch 12 located between the two transistors 16. Said diode 17 is conducting for one direction of the electric current going from its first end to its second end.

[0056] Similarly, the third branch 13 comprises at least one pair of transistors 16, the transistors 16 being connected in series. In addition, the third branch 13 comprises at least two diodes, a diode 17 being connected in parallel with each of the transistors 16.

[0057] Thus, one end of the first of the two diodes 17 is connected here to a point on the third branch 13 located between the two transistors 16. Here the second The end of said diode 17 is connected to the third branch 13 at a point located between one of the two transistors 16 and the first end of the third branch 13. Said diode 17 is conducting for one direction of electric current going from its first end to its second end.

[0058] Thus, a first end of a second of the two diodes 17 is here connected to the third branch 13 at a point located between a second of the two transistors 16 and the second end of the third branch 13. Here, the second end of said second diode 17 is connected to a point of the third branch 13 located between the two transistors 16. Said diode 17 is conducting for one direction of the electric current going from its first end to its second end.

[0059] Similarly, the fourth branch 14 comprises at least one pair of transistors 16, the transistors 16 being connected in series. In addition, the fourth branch 14 comprises at least two diodes, one diode 17 being connected in parallel with each of the transistors 16.

[0060] Thus, a first end of a first of the two diodes 17 is here connected to a point of the fourth branch 14 located between the two transistors 16. Here, the second end of said diode 17 is connected to the fourth branch 14 at a point located between a first of the two transistors 16 and the first end of the fourth branch 14. Said diode 17 is conducting for one direction of the electric current going from its first end to its second end.

[0061] Thus, a first end of a second of the two diodes 17 is here connected to the fourth branch 14 at a point located between a second of the two transistors 16 and the second end of the fourth branch 14. Here, the second end of said second diode 17 is connected to a point of the fourth branch 14 located between the two transistors 16. Said diode 17 is conducting for one direction of the electric current going from its first end to its second end.

[0062] Therefore, in the present case, the second 12, third 13 and fourth 14 branches are identical.

[0063] In a manner known per se, the inverter of the second block 10 is arranged to convert a direct current into an alternating current.

[0064] For this purpose, the first phase 24 is connected to the second branch 12 and for example at a point on the second branch 12 located between the two transistors 16 and more particularly between the connection point of the first end of the first diode 17 and the connection point of the second end of the second diode 17. Potentially, the first phase 24 is thus connected to a midpoint of the second branch 12.

[0065] The second phase 25 is connected to the third branch 13 and, for example, at a point on the third branch 13 located between the two transistors 16 and more particularly between the connection point of the first end of the first diode 17 and the connection point of the second end of the second diode 17. Potentially, the second phase 25 is thus connected to a midpoint of the third branch 13.

[0066] The third phase 26 is connected to the fourth branch 14 and for example at a point on the fourth branch 14 located between the two transistors 16 and more particularly between the connection point of the first end of the first diode 17 and the connection point of the second end of the second diode 17. Potentially, the third phase 26 is thus connected to a midpoint of the fourth branch 14.

[0067] The second block 10 is therefore arranged to impose a given electrical voltage across the terminals of the electric motor 2.

[0068] The third block 18 includes the electric motor 2 previously described with the connection of the three phases of the motor to the inverter of the second block 10 as just described.

[0069] In the present case, the electrical power supply circuit 3 thus comprises successively the first block 4, the fourth block 19, the second block 10, and the third block 18. Therefore, each block is electrically connected to the block or two blocks immediately adjacent to it. The fourth block 19 is arranged between the first block 4 and the second block 10. The second block 10 is arranged between the fourth block 19 and the third block 18. More precisely, the first block 4 is electrically connected to the fourth block 19. The fourth block 19 is electrically connected to the second block 10. Furthermore, the second block 10 is electrically connected to the third block 18 in that the second branch 12, the third branch 13, and the fourth branch 14 of the second block 10 are respectively connected to the first phase 24, second phase 25, and third phase 26 of the electric motor 2 of the third block 18.

[0070] System 1 also includes a processing unit (not shown) and / or is connected to a processing unit of aircraft 100 arranged outside of said system 1.

[0071] The processing unit comprises at least one processing component (electronic and / or software), which is, for example, a general-purpose processor, a microcontroller, or a programmable logic circuit such as an FPGA (Field Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). The processing unit is arranged to provide a torque command to the second block 10, which delivers the corresponding supply voltage to the electric motor 2.

[0072] It should be noted that at least one of the aforementioned transistors is an insulated-gate field-effect transistor, more commonly known by the acronym MOSFET (Metal Oxide Semiconductor Field Effect Transistor). More precisely, at least one of the aforementioned transistors is an N-channel MOSFET, operating when a positive charge is applied.

[0073] A possible operation of the power supply circuit 3 thus detailed will now be described.

[0074] The electric motor 2 here has two distinct operating modes: a motor mode and a generator mode.

[0075] In motor mode, the input voltage Vinput is applied to the power supply circuit 3 and more particularly to the first block 4. A corresponding input current flows and thus passes through the input diode 9 of the first block 4. In this operating mode, no current flows within branch 29.

[0076] At the fourth block 19, adjacent to the first block 4, transistor T1 is conducting and carries an Iconvertisseur current which then flows through inductor 22. In this operating mode, diode DI is reverse-biased, transistor T2 is inactive, and diode D2 is also reverse-biased. Inductor 22 smooths the Iconvertisseur current.

[0077] At the second block 10, adjacent to the fourth block 19, the transistors 16 are rapidly switched alternately to supply the electric motor 2 with a three-phase alternating current from the direct current output of the fourth block 19. To this end, the transistors 16 are controlled by the processing unit to adjust the frequency and / or amplitude of the voltage applied to the electric motor 2, thereby controlling the speed and / or torque of the electric motor 2. Changing the frequency controls the speed, while changing the amplitude controls the torque. The diodes 17, connected in parallel, allow at least one recovery current to flow through the second block 10. This reduces the switching losses of the transistors 16.

[0078] At the level of the third block 18, the electric motor 2 then converts the received electrical energy into mechanical energy.

[0079] In the case where the flight trim is driven by an external force (such as by the pilot), the electric motor 2 operates in generator mode. In generator mode, in a manner known per se, mechanical energy is transformed by the electric motor 2 into electrical energy. An electric current thus flows back into the electrical power supply circuit 3 (a so-called "negative" current because it opposes the current flowing through the converter).

[0080] From then on, this negative current passes through the second block 10 to reach the fourth block 19.

[0081] Then, the fourth block 19 reinjects said negative current into the first block 4.

[0082] The first block 4 will dissipate this negative current, coming from the electric motor 2, in resistance 6 of the first block 4.

[0083] The location of the first block 4 is therefore particularly advantageous because the electrical energy generated by the electric motor 2 in its generator mode will be dissipated in the first block 4 without changing the voltage N conductor across the terminals of the second block 10. Indeed, the converter 30 of the fourth block 19 is arranged between the inverter of the second block 10 and the first block 4 and is indifferent to the direction of current flow.

[0084] Thus, with the electrical power supply circuit 3 described above, the voltage NondUieUr across the terminals of the second block 10 is maintained constant regardless of the operating mode of the motor 2.

[0085] Consequently, the engine torque control piloting is of very good quality throughout the flight of aircraft 100.

[0086] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0087] In particular, although here the motor is a three-phase brushless permanent magnet electric motor, the use of other motors is possible. A synchronous reluctance motor or a permanent magnet synchronous motor could thus be used.

[0088] Although here the aircraft represented is a helicopter, the aircraft may be different and be, for example, an airplane.

[0089] Although here the inverter shown has two levels, the inverter may be different and be, for example, a three, four or five level inverter.

[0090] Although here the current reversible two-quadrant electrical power converter is an electrical voltage step-up chopper, also known as a "Buck-Boost" converter, said converter may be different and be, for example, a full-bridge converter.

Claims

Demands

1. System (1) for managing a flight trimmer of an aircraft (100), the system (1) comprising at least one three-phase electric motor (2) intended to move the flight trimmer in service and the system (1) comprising at least one electrical power supply circuit (3) for said motor (2), the circuit (3) comprising several blocks of which at least: - a first block (4) arranged to dissipate electrical energy that may be generated by the motor (2), - a second block (10) arranged to impose a given electrical voltage across the terminals of the motor (2), - a third block (18) comprising the motor (2), - a fourth block (19) for stabilizing the electrical voltage across the terminals of at least one of the first (4), second (10) or third (18) block;the system (1) being characterized in that the fourth block (19) is arranged between the first block (4) and the second block (10), the fourth block (19) comprising at least one two-quadrant current reversible electrical power converter (30).

2. System (1) according to claim 1, wherein the circuit (3) successively comprises the first block (4), the fourth block (19), the second block (10) and the third block (18), each block being electrically connected to the block or the two blocks immediately adjacent to it.

3. System (1) according to any one of claims 1 or 2, wherein the first block (4) comprises a branch (29) successively comprising a first transistor (5) and a resistor (6), a first diode (7) being mounted in parallel with the first transistor (5) and a second diode (8) being mounted in parallel with the resistor (6), the first block comprising an input diode (9) mounted in series with the branch (29).

4. System (1) according to any one of the preceding claims wherein the converter (30) is an electric voltage step-up chopper.

5. System (1) according to any one of the preceding claims, wherein the converter (30) comprises a first branch (20) comprising two transistors (T1, T2) connected in series, and a diode (Dl, D2) mounted in parallel with each transistor (Tl, T2), and a second branch (21) connected to the first branch between the two transistors (Tl, T2), the second branch (21) comprising an inductance (22).

6. System (1) according to any one of the preceding claims, wherein the second block (10) comprises a power inverter.

7. System (1) according to claim 6, wherein the second block (10) comprises a first branch (11), a second branch (12), a third branch (13) and a fourth branch (14), the first, second, third and fourth branches being mounted in parallel with each other, the first branch (11) comprising a capacitor (15) and the second, third and fourth branches comprising a pair of transistors (16) mounted in series, a diode (17) being mounted in parallel with each transistor (16).

8. System (1) according to any one of the preceding claims, wherein the motor (2) is a permanent magnet brushless three-phase electric motor.

9. System (1) according to any one of claims 1 to 8, comprising a processing unit arranged to drive at least the second block (10).

10. Aircraft (100) comprising a system (1) according to any one of the preceding claims.

Images