Distributed architecture of an aircraft brake system

Abstract

The invention relates to an architecture of a braking system of an aircraft, comprising: - a brake (20) comprising a plurality of electromechanical actuators (26), each electromechanical actuator having a digital communication module; at least one power supply unit (21, 22); two control units (23, 24), each control unit being connected to a separate group of one or more electromechanical actuators and comprising an upstream digital communication module (27), a control module (28) arranged to generate digital control signals (Sn1, Sn2), and a downstream digital communication module (29) connected to the digital communication modules of the electromechanical actuators of the group to transmit the digital control signals to the electromechanical actuators; - a digital communication network (25) to which the upstream digital communication modules (27) of the two control units are connected.

Description

[0001] This invention relates to the field of aircraft electric braking systems. BACKGROUND

[0003] Figure 1 shows a conventional so-called “centralized” electric braking system used in aircraft.

[0004] In this architecture, each brake 1 used to brake the aircraft's wheels includes a friction component (e.g., a carbon disc stack) and four electromechanical actuators 2, which are grouped into two different groups, with two electromechanical actuators 2 in each group. The electromechanical actuators 2 in either group are connected to the same centralized computer 3 located in the aircraft's fuselage.

[0005] The aircraft's pilot (or autopilot system) generates braking setpoints.

[0006] Each centralized computer 3 acquires the braking setpoint and performs monitoring and control of the electromechanical actuator 2 connected to it. The monitoring and control of the electromechanical actuator 2 utilizes one or more servo control loops.

[0007] Therefore, the centralized computer 3 generates a three-phase power supply current to power the motor of each electromechanical actuator 2 connected thereto. The three-phase power supply current is transmitted to the motor, which then actuates the actuator of the electromechanical actuator 2. The actuator slides, applying a braking force to the friction member of the brake 1, and thus applying a braking torque to the wheel.

[0008] Each centralized computer 3 also acquires measurements of one or more servo control parameters, obtained by sensors located in each electromechanical actuator 2 to which the centralized computer 3 is connected (or nearby: on the brake 1, on the wheel, etc.). For example, these measurements include measurements of the angular position of the motor's rotor. These measurements constitute the return signal of the aforementioned servo control loop.

[0009] This centralized architecture has some drawbacks.

[0010] This architecture requires at least nine wires for each electromechanical actuator 2: three power supply wires 4 for the three phases of the motor (represented by a single wire in Figure 1), four communication wires 5 (represented by a single wire in Figure 1) for returning the servo-control parameter measurements to the centralized computer 3, and two power supply wires 6 (represented by a single wire in Figure 1) for powering the blocking member for blocking the electromechanical actuator 2 in order to provide a parking brake. These wires are integrated in a wire harness extending downwards from the aircraft fuselage to the brake 1 and are therefore bulky and heavy. The length of the wire harness in which the power supply wires 4 extend to carry the current for powering the motor makes it necessary to use filtering circuits for electromagnetic compatibility, thereby increasing the weight, complexity and cost of the centralized computer 3.

[0011] In order to mitigate these drawbacks, it has been proposed to use a distributed architecture, as illustrated in Figure 2.

[0012] In this architecture, each electromechanical actuator 10 of the brake 11 comprises not only its motor and its brake, but also a power module and a digital communication module 12. The digital communication modules 12 of the brake 11 and the electromechanical actuators 10 are interconnected in order to form a digital network. This architecture also has two power supply units 14 for powering the electromechanical actuators 10 of the brake 11 by delivering a supply voltage to their power modules and two control units 15 adapted to generate digital control signals for the motors, which are sent to the digital communication modules 12. The digital communication module 12 of each electromechanical actuator 10 transmits the digital control signals to the power module, so that each power module generates and draws a supply current from the supply voltage based on its digital control signal. Finally, this architecture comprises a network interconnection member 16 connected to both control units 15 and integrated in the digital network in order to distribute the digital control signals to the digital communication modules 12 of the electromechanical actuators 10 via the digital network. In this architecture, the generation of the supply current for the motor is thus "distributed" between the electromechanical actuators.

[0013] This architecture is the most advantageous and serves to solve the problems mentioned above.

[0014] However, this architecture also has some drawbacks.

[0015] In particular, it can be seen that the interconnection member 16 forms a "common point" in the control system with the two control units 15, so that a single fault in the interconnection member 16 can lead to a complete loss of braking on the wheel.

[0016] Moreover, it has been proposed to position the connection member 16 in the vicinity of the machine wheels, at the bottom of the landing gear. This position is problematic because it is in an area where the environmental conditions are particularly harsh, and therefore not suitable for housing electronic devices. Moreover, this area has very little available space, making it complex to "physically" integrate the connection member 16 on the landing gear.

[0017] OBJECTS

[0018] An object of the present application is to provide an architecture for an aircraft braking system that benefits from the advantages of a distributed architecture, but without the above-mentioned drawbacks. SUMMARY

[0019] To achieve this object, there is provided an architecture for an aircraft braking system, the architecture comprising:

[0020] a brake for braking an aircraft machine wheel, the brake comprising a friction member and a plurality of electromechanical actuators for applying a braking force to the friction member and thus a braking torque on the machine wheel, each electromechanical actuator comprising an electric motor, a power module for generating a supply current for the electric motor, and a digital communication module;

[0021] at least one power supply unit for supplying power to the power modules by delivering a supply voltage thereto;

[0022] two control units, each control unit being connected to a different group of one or more electromechanical actuators, and comprising an upstream digital communication module, a control module arranged to generate a digital control signal, and a downstream digital communication module connected to the digital communication modules of the electromechanical actuators of said group so as to transmit the digital control signal to the power modules of said electromechanical actuators, so that each power module generates a supply current based on the digital control signal and from the supply voltage; and

[0023] a digital communication network to which the upstream digital communication modules of the two control units are connected.

[0024] Thus, in the architecture of the present application, the supply current for each electric motor is generated within the electromechanical actuator, making it possible to benefit from the advantages of a distributed architecture, as mentioned above.

[0025] This architecture can also benefit from the advantages of a centralized architecture.

[0026] In particular, the electromechanical actuators of a given brake can be controlled by control units integrated in two different housings, without such an architecture requiring a separate equipment piece to perform the function of the connection member described above. This avoids any loss of braking for one of the machine wheels in the event of a single failure.

[0027] Thus, this improves the reliability of the braking system by reducing the number of electronics located at the bottom of the landing gear, and the integration of the system becomes simpler. By reducing the number of equipment pieces in the system, the recurrent costs of the braking system are also reduced.

[0028] There is also provided an architecture as described above, wherein the brake comprises two distinct groups, each group comprising two electromechanical actuators, and wherein each control unit is connected to the two electromechanical actuators of a respective one of the two distinct groups, so as to control them.

[0029] There is also provided an architecture as described above, comprising a plurality of brakes (each brake for braking a different wheel of the aircraft), two control units associated with each brake, and a housing, each housing integrating the two control units.

[0030] There is also provided an architecture as described above, wherein the two control units associated with a given brake are integrated in two distinct housings.

[0031] There is also provided an architecture as described above, wherein the two control units integrated in a given housing have at least partially different hardware and / or software design.

[0032] There is also provided an architecture as described above, wherein the two control units associated with a given brake have at least partially different hardware and / or software design.

[0033] There is also provided an architecture as described above, wherein the electromechanical actuators of the brake are arranged to transmit digital measurement signals to the control module of the control unit via a digital communication module of the electromechanical actuators and a downstream digital communication module of the control unit.

[0034] The present invention can be better understood in light of the following description of specific non-limiting embodiments of the invention. BRIEF DESCRIPTION OF DRAWINGS

[0035] With reference to the appended drawings, in which:

[0036] Figure 1 shows a brake and two centralized computers in a centralized prior art architecture;

[0037] Figure 2 shows a brake, two power supply units, two control units and interconnection means in a distributed prior art architecture;

[0038] FIG. 3 Figure 3 shows a brake, two power supply units, two control units and a digital communication network in an architecture of the invention; and

[0039] FIG. 4 is a figure similar to FIG. 3 Figure 1, wherein two brakes and four control units are integrated in two housings. Detailed Implementation

[0040] The invention is described below as being implemented in an aircraft having multiple main landing gears, each main landing gear carrying multiple so-called "brake" wheels, i.e. multiple aircraft wheels, each aircraft wheel being equipped with a brake for braking the aircraft.

[0041] refer to FIG. 3 In this example, for each brake wheel of the aircraft, the architecture of the braking system of the present invention includes a brake 20, a first power supply unit 21, a second power supply unit 22, a first control unit 23, a second control unit 24, and a digital communication network 25 as an advanced network (HLN).

[0042] The brake 20 includes an actuator carrier on which four electromechanical brake actuators 26 and friction components, specifically carbon disc stacks, are mounted.

[0043] Four electromechanical actuators 26 are used to apply braking force to the carbon disc stack, thereby applying braking torque to the wheels, slowing the rotation of the wheels, and thus braking the aircraft when it is on the ground.

[0044] Each electromechanical actuator 26 includes a body fastened to an actuator carrier, a actuator, and a blocking member adapted to hold the actuator in place. A motor, a power supply module, and a digital communication module are integrated into the body of each electromechanical actuator 26.

[0045] The actuator is driven by an electric motor to slide the carbon disk stack and apply braking force to the carbon disk stack.

[0046] The power module generates an AC supply current that flows through the three phases of the motor when appropriate to actuate the actuator and thus brake the wheels. For this purpose, the power module includes an inverter comprising multiple switches controlled to convert a DC supply voltage Vc into a three-phase AC voltage used to generate the supply current for the motor.

[0047] The four electromechanical actuators 26 are grouped into different first and second groups, the first group including two electromechanical actuators 26a and the second group including two electromechanical actuators 26b.

[0048] The term "different group" should be understood to mean that an electromechanical actuator belonging to one group does not belong to another group.

[0049] It should be noted that when viewed from the rear, brake 20 faces upwards, as... FIG. 3As illustrated, the first group comprises one electromechanical actuator 26a located in the upper left part of the actuator carrier and one electromechanical actuator 26a located in the lower right part of the actuator carrier, while the second group comprises one electromechanical actuator 26b located in the upper right part of the actuator carrier and one electromechanical actuator 26b located in the lower left part of the actuator carrier. Thus, for example, in the event of loss of one of the groups due to loss of part of the control system, resulting in loss of half of the wheel brakes, while still retaining braking on the left and right sides and on the top and bottom of the brakes 20.

[0050] The first power supply unit 21 and the second power supply unit 22 are intended to supply power to the power modules of the four electromechanical actuators 26.

[0051] The first power supply unit 21 delivers a supply voltage Vc to the power modules of the electromechanical actuators 26a of the first group, while the second power supply unit 22 delivers a supply voltage Vc to the power modules of the electromechanical actuators 26b of the second group.

[0052] The first power supply unit 21 and the second power supply unit 22 are located in the fuselage at the top of the landing gear inside the cabin of the aircraft.

[0053] Likewise, the first control unit 23 and the second control unit 24 are located in the fuselage.

[0054] Each of the first and second control units 23 and 24 comprises a respective upstream digital communication module 27, a respective control module 28 and a respective downstream digital communication module 29.

[0055] The first control unit 23 is connected to the electromechanical actuators 26a of the first group in order to control them. The second control unit 24 is connected to the electromechanical actuators 26b of the second group in order to control them.

[0056] The downstream digital communication module 29 of the first control unit 23 is connected to the digital communication modules of the electromechanical actuators 26a of the first group. The downstream digital communication module 29 of the second control unit 24 is connected to the digital communication modules of the electromechanical actuators 26b of the second group.

[0057] The upstream digital communication module 27 of the first control unit 23 and the upstream digital communication module 27 of the second control unit 24 are connected to the digital communication network 25.

[0058] Thus, when a braking setpoint is generated by the pilot or the autopilot system of the aircraft, the braking setpoint is converted into a digital setpoint signal Sn0 which is propagated by the digital communication network 25.

[0059] The upstream digital communication module 27 of the first control unit 23 collects the digital setpoint signals SnO and transmits them to the control module 28 of the first control unit 23. The control module 28 implements one or more servo control loops and generates first digital control signals SnI. The first digital control signals SnI are transmitted to the downstream digital communication module 29 of the first control unit 23, which transmits them to the first group of electromechanical actuators 26a.

[0060] The digital communication module of each electromechanical actuator 26a of the first group collects the first digital control signals SnI and transmits them to the power module of said electromechanical actuator 26a. The power module of the electromechanical actuator 26a generates and draws a supply current from the supply voltage Vc on the basis of the first digital control signals SnI. When energized, the motor actuates the pusher of the electromechanical actuator 26a in order to brake the wheel.

[0061] Measurements of servo control parameters are made in each electromechanical actuator 26a. By way of example, these measurements are measurements of the angular position and / or angular velocity of the rotor of the motor, measurements of the supply current, measurements of the pusher position, etc. These measurements are digitized and they form first digital measurement signals SmI which are transmitted by the electromechanical actuator 26a to the control module 28 of the first control unit 23 via the digital communication module of the electromechanical actuator 26a and the downstream digital communication module 29 of the first control unit 23.

[0062] These first digital measurement signals SmI constitute the return signals of the above-mentioned servo control loops.

[0063] Likewise, the upstream digital communication module 27 of the second control unit 24 collects the digital setpoint signals SnO and transmits them to the control module 28 of the second control unit 24. The control module 28 implements one or more servo control loops and generates second digital control signals Sn2. The second digital control signals Sn2 are transmitted to the downstream digital communication module 29 of the second control unit 24, which transmits them to the second group of electromechanical actuators 26b.

[0064] The digital communication module of each electromechanical actuator 26b of the second group collects the second digital control signals Sn2 and transmits them to the power module of said electromechanical actuator 26b. The power module of the electromechanical actuator 26b generates and draws a supply current from the supply voltage Vc on the basis of the second digital control signals Sn2. When energized, the motor actuates the pusher of the electromechanical actuator 26b in order to brake the wheel.

[0065] The measurements of the servo-control parameters are made in each electromechanical actuator 26b. By way of example, these measurements are the measurements of the angular position and / or of the angular speed of the rotor of the electric motor, of the supply current, of the pusher position, etc. These measurements are digitized and they form second digital measurement signals Sm2 which are transmitted by the electromechanical actuators 26b to the control module 28 of the second control unit 24 via the digital communication module of the electromechanical actuators 26b and the downstream digital communication module 29 of the second control unit 24. These second digital measurement signals Sm2 constitute the return signals of the above-mentioned servo-control loop.

[0066] It should be observed that the first and second digital control signals Sn1 and Sn2 can be identical or they can be different and therefore dedicated respectively to the first group of electromechanical actuators 26a and to the second group of electromechanical actuators 26b.

[0067] Likewise, in the first digital control signals Sn1, the digital control signals for each electromechanical actuator 26a can be identical or they can also be different. In the second digital control signals Sn2, the digital control signals for each electromechanical actuator 26b can be identical or they can also be different.

[0068] The two control units 23 and 24 are therefore interconnected and the two digital communication modules of the electromechanical actuators 26 are interconnected by means of the digital communication network 25.

[0069] Advantageously, this architecture comprises two control units associated with each brake, and a housing, each housing integrating the two control units. Each housing therefore forms, with the two control units integrated in said housing, a single equipment item.

[0070] The two control units of the electromechanical actuators connected to a single brake are integrated into two different housings.

[0071] The first control unit 31 of the first housing 30 is therefore connected to the electromechanical actuators 36a of the first group of electromechanical actuators of the first brake 37 in order to control them. The second control unit 32 of the first housing 30 is connected to the electromechanical actuators 38a of the first group of electromechanical actuators of the second brake 39 in order to control them. FIG. 4 The first control unit 34 of the second housing 33 is therefore connected to the electromechanical actuators 36b of the second group of electromechanical actuators of the first brake 37 in order to control them. The second control unit 35 of the second housing 33 is connected to the electromechanical actuators 38b of the second group of electromechanical actuators of the second brake 39 in order to control them. FIG. 4 In the example of figure 1, the power supply units are not shown.

[0072] The first control unit 31 of the first housing 30 is therefore connected to the electromechanical actuators 36a of the first group of electromechanical actuators of the first brake 37 in order to control them. The second control unit 32 of the first housing 30 is connected to the electromechanical actuators 38a of the first group of electromechanical actuators of the second brake 39 in order to control them.

[0073] Likewise, the first control unit 34 of the second housing 33 is connected to the electromechanical actuators 36b of the second group of electromechanical actuators of the first brake 37, in order to control them. The second control unit 35 of the second housing 33 is connected to the electromechanical actuators 38b of the second group of electromechanical actuators of the second brake 39, in order to control them.

[0074] The first and second control units 31 and 33 of the first housing 30 and the first and second control units 34 and 35 of the second housing 33 are all connected to a digital communication network 40.

[0075] The first and second housings 30 and 32 are identical, so as to simplify the equipment management. The first control unit 31 and the second control unit 35 are identical. The second control unit 32 and the first control unit 34 are identical.

[0076] Advantageously, the two control units integrated in a given housing have at least partially different hardware and / or software designs.

[0077] Thus, the first and second control units 31 and 32 integrated in the first housing 30 are at least partially different in their hardware and / or software design (i.e. they comprise different electronic component(s) and / or software module(s)). The first and second control units 34 and 35 integrated in the second housing 33 are at least partially different in their hardware and / or software design.

[0078] Likewise, the two control units associated with a given brake have at least partially different hardware and / or software designs.

[0079] Thus, the first control units 31 and 34 associated with the first brake 37 are at least partially different in their hardware and / or software design. The second control units 32 and 35 associated with the second brake 39 are at least partially different in their hardware and / or software design.

[0080] These differences serve to avoid a common-mode failure of a component in one control unit leading to a complete loss of braking by the housing controlled brakes: a common-mode failure of all control units of a given type would lead to a loss of braking of both actuators of each brake, which is preferable to losing all braking on any one brake.

[0081] Thus, the braking system architecture is based on two levels of digital communication, which makes it possible to integrate different functional modules in a minimum number of housings, while also making it possible to distribute the control of the electromechanical actuators of a given brake among different housings.

[0082] Naturally, the application is not limited to the embodiments described, but encompasses any variants falling within the scope of the application as defined by the claims.

[0083] Of course, it can be provided that the number of electromechanical actuators of each brake is not four. Thus, each housing can integrate more than two control units. Each control unit can control more than two electromechanical actuators. Depending on the control unit, the number of electromechanical actuators controlled by each control unit can be different.

Claims

1. An architecture for an aircraft braking system, the architecture comprising: Brakes (20; 37, 39) for braking the wheels of the aircraft, the brakes including friction members and a plurality of electromechanical actuators (26; 36, 38) for applying braking force to the friction members and thereby applying braking torque to the wheels, each electromechanical actuator including a motor, a power module for generating power supply current for the motor, and a digital communication module; At least one power supply unit (21, 22) in the fuselage of the aircraft is used to supply power to the power module by supplying a power supply voltage (Vc) to the power module; Two control units (23, 24; 31, 32, 34, 35) are located in the fuselage of the aircraft. Each control unit is connected to a different group of one or more electromechanical actuators and includes an upstream digital communication module (27), a control module (28) arranged to generate digital control signals (Sn1, Sn2), and a downstream digital communication module (29) connected to the digital communication modules of the electromechanical actuators in the group to transmit the digital control signals to the power modules of the electromechanical actuators, such that each power module generates and obtains a supply current from the supply voltage based on the digital control signals. as well as Digital communication network (25; 40), the upstream digital communication modules (27) of the two control units are connected to the digital communication network; The architecture includes multiple brakes (37, 39), each brake for braking different wheels of the aircraft; two control units (31, 32, 34, 35) associated with each brake; and housings (30, 33), each housing integrating two control units, the two control units associated with a given brake being integrated into two different housings.

2. The architecture according to claim 1, characterized in that, The brake comprises two distinct groups, each group comprising two electromechanical actuators (26a, 26b), and wherein each control unit is connected to the two electromechanical actuators of the corresponding group in order to control them.

3. The architecture according to claim 1, characterized in that, The two control units integrated in a given housing have at least partially different hardware and / or software designs.

4. The architecture according to claim 1, characterized in that, The two control units associated with a given brake have at least partially different hardware and / or software designs.

5. The architecture according to any one of the preceding claims, characterized in that, The electromechanical actuator (26) of the brake (20) is arranged to transmit digital measurement signals (Sm1, Sm2) to the control module (28) of the control unit (23, 24) via the digital communication module of the electromechanical actuator and the downstream digital communication module (29) of the control unit.

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