阅读说明：本技术 用于双起落架飞行器的制动系统 (Braking system for a dual-landing-gear aircraft ) 是由 T·R·哈伯德 D·T·山本 于 2019-06-27 设计创作，主要内容包括：用于双起落架飞行器的制动系统。所述制动系统将外侧制动控制配对成外侧制动系统控制单元(BSCU)并且将内侧制动控制配对成第二内侧制动系统控制单元(BSCU)。每个BSCU设计有两个独立的控制通道,在这两个独立的控制通道中,前轮组在一个控制通道中配对,而后轮在另一控制通道上配对。经由前后轮配对中安装的备用制动模块来提供备用制动。(A braking system for a dual landing gear aircraft. The brake system pairs outboard brake control to an outboard Brake System Control Unit (BSCU) and pairs inboard brake control to a second inboard Brake System Control Unit (BSCU). Each BSCU is designed with two independent control channels, where the front wheel set is paired in one control channel and the rear wheel is paired on the other control channel. The backup braking is provided via backup brake modules installed in the front and rear wheel pairs.)

1. A braking system (10) for a dual-landing-gear aircraft including left and right landing gears each having forward and aft inboard wheels and outboard wheels, the braking system comprising:

an outboard brake system control unit (20) including at least a first processing circuit (21) that generates brake control signals in response to pilot input to symmetrically control braking of a first wheel pair including only the front outboard wheel (69) and a second wheel pair including only the rear outboard wheel (69);

an inboard brake system control unit (30) including at least a second processing circuit (21) responsive to the pilot input to generate brake control signals to symmetrically control braking of a third wheel pair including only the front inboard wheel (69) and a fourth wheel pair including only the rear inboard wheel (69), the inboard brake system control unit (30) being independent of the outboard brake system control unit (20); and

a hydraulic system (40) that applies a braking force to the wheels (69) in response to the brake control signal.

2. The braking system according to claim 1, wherein the outboard brake system control unit (20) sends the braking control signal along a first control channel (91) to brake only the forward outboard wheels (69) of both the left and right landing gears, and sends the braking control signal along a second control channel (92) to brake only the aft outboard wheels (69) of both the left and right landing gears, the first control channel (91) being independent of the second control channel (92).

3. The braking system of claim 2, wherein the inboard brake system control unit (30) sends the brake control signal along a third control channel (93) to brake only the forward inboard wheels (69) of both the left and right landing gears, and sends the brake control signal along a fourth control channel (94) to brake only the aft inboard wheels (69) of both the left and right landing gears, the third control channel (93) being independent of the fourth control channel (94).

4. The braking system of claim 1, wherein the inboard brake system control unit (20) and the outboard brake system control unit (30) further include an input interface (23) that receives the pilot input, the pilot input including separate first and second inputs.

5. The braking system of claim 1, wherein the hydraulic system (40) comprises:

a first hydraulic line (49) and a backup line (75) supplying hydraulic fluid to the brakes (50) at the wheels (69);

a servo valve (46) positioned along the first hydraulic line (49) and the backup line (75) to regulate a pressure of hydraulic fluid supplied to the brakes (50) in response to the brake control signals received from the inboard brake system control unit (20) and the outboard brake system control unit (30);

a shuttle valve (81) operatively connecting the first hydraulic line (49) and the backup line (75), the shuttle valve (81) supplying hydraulic fluid from one of the first hydraulic line (49) and the backup line (75).

6. A braking system according to claim 5 wherein each servo valve (46) located along the first hydraulic line (49) regulates the pressure to one of the brakes (50) and a servo valve (46) located along the backup supply line (75) regulates the pressure to a pair of brakes (50) on one of the left and right landing gears.

7. The braking system of claim 5, further comprising: a first module (41) housing each servo valve (46) regulating the pressure of hydraulic fluid along the first hydraulic line (49) to a brake (50) of one of the left and right landing gears; and a second module (42) housing each servo valve (46) regulating the pressure of hydraulic fluid along the second hydraulic line (75) to the brakes (50) of the other of the left and right landing gears.

8. The braking system of claim 7, wherein each of the first and second modules (41, 42) includes a shut-off valve (47) for reducing leakage of hydraulic fluid.

9. The brake system according to claim 5, wherein the outboard brake system control unit (20) controls a servo valve (46) that supplies hydraulic fluid to each of the front and rear outboard wheels (69), and the inboard brake system control unit (30) controls a servo valve (46) that supplies hydraulic fluid to each of the front and rear inboard wheels (69).

10. An aircraft having a brake system (10) according to claim 1.

11. A braking system (10) for a dual-landing-gear aircraft including left and right landing gears each having forward and aft inboard wheels and outboard wheels, the braking system comprising:

a hydraulic system (40) comprising a plurality of sets of supply lines (49, 75, 82) each supplying hydraulic fluid to control braking of one of the wheels (69), each of the plurality of sets of supply lines (49, 75, 82) comprising:

a plurality of valves (46, 47, 81);

a brake (50) that applies a braking force to one of the wheels (69);

an outboard brake system control unit (20) including first processing circuitry (21) responsive to pilot input to generate brake control signals to control valves (46, 47, 81) of a first wheel pair including only the forward outboard wheels (69) and valves (46, 47, 81) of a second wheel pair including only the aft outboard wheels (69); and

an inboard brake system control unit (30) comprising second processing circuitry (21) that generates brake control signals to control valves (46, 47, 81) of a third wheel pair comprising only the front inboard wheels (69) and valves (46, 47, 81) of a fourth wheel pair comprising only the rear inboard wheels (69);

the outboard brake system control unit (20) and the inboard brake system control unit (30) receive pilot input and control valves (46, 47, 81) of each wheel pair (69) to apply a symmetric braking force to the wheels (69) of each wheel pair.

12. The braking system of claim 11, further comprising:

a first control passage (91) extending between the outboard brake system control unit (20) and one of the valves (46) on one of the supply lines (49) of the front outboard wheels (69);

a second control passage (92) extending between the outboard brake system control unit (20) and one of the valves (46) on one of the supply lines (49) of the rear outboard wheel (69);

a third control passage (93) extending between the inboard brake system control unit (30) and one of the valves (46) on one of the supply lines (49) of the front inboard wheels (69); and

a fourth control passage (94) extending between the inboard brake system control unit (30) and one of the valves (46) on one of the supply lines (49) of the rear inboard wheel (69);

the first control passage (91), the second control passage (92), the third control passage (93), and the fourth control passage (94) are independent of each other.

13. A method of braking an aircraft, the method comprising the steps of:

receiving pilot input at both an outboard brake system control unit (20) and an inboard brake system control unit (30);

sending a first brake signal from the outboard brake system control unit (20) based on the pilot input and symmetrically braking a first pair of forward outboard wheels (69) of right and left landing gears and a second pair of aft outboard wheels (69) on the right and left landing gears; and

based on the pilot input, sending a second brake signal from the inboard brake system control unit (30) and symmetrically braking a third pair of front inboard wheels (69) of the right and left landing gears and a fourth pair of rear inboard wheels (69) on the right and left landing gears.

14. The method of claim 13, further comprising the steps of: -sending the first braking signal from the outside brake system control unit (20) to the first pair of front outside wheels (69) via a first control channel (91), and-sending the first braking signal from the outside brake system control unit (20) to the second pair of rear outside wheels (69) via an independent second control channel (92).

15. The method of claim 14, further comprising the steps of: sending the second brake signal from the inboard brake system control unit (30) to the third pair of front inner wheels (69) via a third control channel (93), and sending the second brake signal from the inboard brake system control unit (30) to the fourth pair of rear inner wheels via an independent fourth control channel (94).

Technical Field

The present disclosure relates generally to aircraft braking systems, and more particularly to brake pairing schemes for dual landing gear aircraft that create a direct and robust braking system.

Background

The aircraft may include a dual landing gear architecture including a plurality of wheel sets. Each wheel set includes a plurality of wheels arranged in two or more inboard wheels and two or more outboard wheels. The wheels are also arranged as a front wheel set closer to the front of the aircraft and a rear wheel set towards the rear of the aircraft.

Conventional braking systems divide the aircraft into left and right braking systems. Failures in these conventional systems result in an asymmetric loss of brakes applying braking along only one side of the aircraft. This results in an increased pilot workload and may also hinder subsequent dispatch (dispatch) of the aircraft. These conventional systems also typically include complex and expensive redundancy and monitoring systems.

Accordingly, there is a need for aircraft brake systems that reduce and/or prevent asymmetric loss of braking.

Disclosure of Invention

The present application is directed to providing a brake system for an aircraft. The braking system is configured to provide symmetric braking of a wheel of an aircraft.

One aspect is directed to a braking system for a dual landing gear aircraft including left and right landing gears each having forward and aft inboard wheels and forward and outboard wheels. The brake system includes an outboard brake system control unit having at least a first processing circuit responsive to pilot input to generate brake control signals to symmetrically control braking of a first wheel pair including only the front outboard wheels and a second wheel pair including only the rear outboard wheels. The inboard brake system control unit includes at least a second processing circuit responsive to the pilot input to generate brake control signals to symmetrically control braking of a third wheel pair including only the front inboard wheel and a fourth wheel pair including only the rear inboard wheel. The inboard brake system control unit is independent of the outboard brake system control unit. A hydraulic system applies a braking force to the wheels in response to the brake control signal.

In one aspect, the outboard brake system control unit sends the brake control signal along a first control channel (control lane) to brake only the forward outboard wheels of both the left and right landing gears, and sends the brake control signal along a second control channel to brake only the aft outboard wheels of both the left and right landing gears, and the first control channel is independent of the second control channel.

In one aspect, the inboard brake system control unit sends the brake control signal along a third control channel to brake only the forward inner wheels of both the left and right landing gears and sends the brake control signal along a fourth control channel to brake only the rear inner wheels of both the left and right landing gears, and the third control channel is independent of the fourth control channel.

In one aspect, the inboard and outboard brake system control units further include an input interface configured to receive the pilot input, and the pilot input includes separate first and second inputs.

In one aspect, the hydraulic system includes: a first hydraulic line and a backup line that supply hydraulic fluid to brakes at the wheel; a servo valve positioned along the first hydraulic line and the backup line, the servo valve regulating a pressure of the hydraulic fluid supplied to the brakes in response to the brake control signals received from the first and second brake system control units; a shuttle valve operatively connecting the first hydraulic line and the backup line, and configured to supply hydraulic fluid from one of the first hydraulic line and the backup line.

In one aspect, each of the servo valves located along the first hydraulic line regulates pressure to one of the brakes, and the servo valve located along the backup supply line regulates a pair of the brakes on one of the left and right landing gears.

In one aspect, a first module houses each servo valve that regulates pressure of hydraulic fluid to brakes of one of the left and right landing gears along the first hydraulic line, and a second module houses each servo valve that regulates pressure of hydraulic fluid to brakes of the other of the left and right landing gears along the second hydraulic line.

In one aspect, each of the first and second modules includes a shut-off valve that reduces leakage of hydraulic fluid.

In one aspect, the outboard brake system control unit controls a servo valve that supplies hydraulic fluid to each of the front and rear outboard wheels, and the inboard brake system control unit controls a servo valve that supplies hydraulic fluid to each of the front and rear inboard wheels.

One aspect is directed to an aircraft having a braking system including an outboard brake system control unit having at least a first processing circuit that generates brake control signals in response to pilot input to symmetrically control braking of a first wheel pair including only the front outboard wheels and a second wheel pair including only the rear outboard wheels. The brake system includes an inboard brake system control unit including at least a second processing circuit responsive to the pilot input to generate brake control signals to symmetrically control braking of a third wheel pair including only the front inboard wheel and a fourth wheel pair including only the rear inboard wheel. The inboard brake system control unit is independent of the outboard brake system control unit. The brake system includes a hydraulic system that applies a braking force to the wheels in response to the brake control signal.

One aspect is directed to a braking system for a dual landing gear aircraft having left and right landing gears each having forward and aft inboard wheels and forward and outboard wheels. The braking system includes a hydraulic system having a plurality of supply lines that each supply hydraulic fluid to control braking of one of the wheels. Each of the supply lines includes a plurality of valves and a brake for applying a braking force to one of the wheels. The brake system includes an outboard brake system control unit having first processing circuitry responsive to pilot input to generate brake control signals to control valves of a first wheel pair having only the front outboard wheels and valves of a second wheel pair having only the rear outboard wheels. The inboard brake system control unit includes a second processing circuit that generates brake control signals to control the valves of the third pair of wheels having only the front inboard wheels and the valves of the fourth pair of wheels having only the rear inboard wheels. The outboard and inboard brake system control units receive pilot input and control valves of each of the wheel pairs to apply symmetric braking forces to the wheels of each of the wheel pairs.

In one aspect, a first control passage extends between the outboard brake system control unit and one of the valves on one of the supply lines of the forward outboard wheel, a second control passage extends between the outboard brake system control unit and one of the valves on one of the supply lines of the rearward outboard wheel, a third control passage extends between the inboard brake system control unit and one of the valves on one of the supply lines of the forward inboard wheel, and a fourth control passage extends between the inboard brake system control unit and one of the valves on one of the supply lines of the rearward inboard wheel, and each of the control passages is independent of the other.

In one aspect, the hydraulic system includes a first hydraulic supply line and a backup hydraulic supply line, and each of the supply lines further includes a shuttle valve that selectively delivers the hydraulic fluid to the brakes from one of the first hydraulic supply line and the backup hydraulic supply line based on the pilot input.

In one aspect, each of the inboard and outboard brake system control units receives pilot input from both a first pilot and a second pilot.

One aspect is directed to a method of braking an aircraft. The method comprises the following steps: pilot input is received at both the outboard brake system control unit and the inboard brake system control unit. The method comprises the following steps: based on the pilot input, a first brake signal is sent from the outboard brake system control unit and symmetrically brakes a first pair of forward outboard wheels on a right landing gear and a left landing gear and a second pair of aft outboard wheels on the right landing gear and the left landing gear. The method comprises the following steps: based on the pilot input, sending a second brake signal from the inboard brake system control unit and symmetrically braking a third pair of rear inboard wheels on the right and left landing gears and a fourth pair of rear inboard wheels on the right and left landing gears.

In one aspect, the method comprises the steps of: the first brake signal is sent from the outboard brake system control unit to the first pair of front outboard wheels via a first control channel, and the first brake signal is sent from the outboard brake system control unit to the second pair of rear outboard wheels via an independent second control channel.

In one aspect, the method comprises the steps of: transmitting the second brake signal from the inboard brake system control unit to the third pair of front inner wheels via a third control channel, and transmitting the second brake signal from the inboard brake system control unit to the fourth pair of rear inner wheels via an independent fourth control channel.

In one aspect, the method comprises the steps of: determining a greater of a first input and a second input from the pilot input, and based on the greater of the first input and the second input, sending the first braking signal from the outboard brake system control unit to symmetrically brake the first pair of outboard wheels and the second pair of outboard wheels, and based on the greater of the first input and the second input, sending the second braking signal from the inboard brake system control unit to symmetrically brake the third pair of inboard wheels and the fourth pair of inboard wheels.

In one aspect, the method comprises the steps of: determining a lesser of the braking commands between the front and rear pairs of wheels from pilot input, and controlling backup braking based on the lesser of the braking commands between the front and rear pairs of wheels.

In one aspect, the method comprises the steps of: sending the braking signal to a servo valve and regulating the flow of hydraulic fluid to regulate the braking of the plurality of pairs of brakes.

Drawings

FIG. 1 is a schematic view of a braking system.

FIG. 2 is a schematic view of a dual landing gear having a pair of wheel sets on opposite sides of a longitudinal axis.

FIG. 3 is a schematic diagram of a braking system that receives pedal input and controls braking of wheels on the landing gear.

FIG. 4 is a schematic view of one of the inboard and outboard brake system control units.

FIG. 5 is a schematic diagram for generating braking commands in a braking system control unit.

Fig. 6 is a schematic diagram of a hydraulic system.

FIG. 7 is a flow chart of a method of braking an aircraft.

Detailed Description

The present application is directed to a braking system for use with a dual landing gear aircraft. The brake system pairs outboard brake control to an outboard Brake System Control Unit (BSCU) and pairs inboard brake control to a second inboard Brake System Control Unit (BSCU). Each BSCU is designed with two independent control channels, of which the front wheel set is paired in one control channel and the rear wheel is paired on the other control channel. Locking wheel and water craft protection is provided through communication between control channels within a given BSCU. Backup braking is provided via backup brake modules installed in front and rear wheel pairs and is commanded via a controlled channel shared with each BSCU. This architecture optimally fuses the preferred inboard/outboard architectures while keeping the control valve close to the brake.

Each BSCU receives brake control signals from the pedals from the first pilot and the second pilot. The BSCU logic causes the greater of the first pilot command and the second pilot command to be selected when a pressure below the slip pressure of the tires is applied to the brakes. The braking command is generated via an antiskid function in the case of a pressure higher than the slip pressure of the tire. The backup brake control command is generated using a lesser of the braking commands between the front and rear wheel pairs.

FIG. 1 is a schematic representation of a braking system 10 for an aircraft having a pair of wheel sets 60. Braking system 10 includes an outboard BSCU20 and an inboard BSCU 30. Each of the outboard BSCU20 and the inboard BSCU30 receives input from a pilot's brake pedal 65. The outboard BSCU20 and the inboard BSCU30 independently generate and apply brake actuator control signals to the hydraulic system 40 to independently control the brakes on the wheels 69 of the aircraft's wheel set 60.

The braking system 10 is configured for use with an aircraft having landing gear with dual wheel sets 60, as shown in fig. 2. The wheel sets 60 may be positioned on opposite sides (i.e., right and left sides) of a longitudinal centerline C of the aircraft. Additionally or alternatively, the wheel sets 60 may be positioned on the same side of the longitudinal centerline C. Each wheel set 60 is depicted in a two-dimensional array having a row 61 including two or more front wheels 69 and a row 62 including two or more rear wheels 69. Wheel set 60 is also aligned to include an inboard row 63 of two or more wheels 69, inboard row 63 being closer to centerline C than an outboard row 64 being further from centerline C. The wheel set 60 may include a variety of arrangements including, but not limited to, one or more rows of three or more wheels 69.

Fig. 3 illustrates a more detailed schematic representation of the brake system 10 within the environment of an aircraft. The braking system 10 is positioned to receive signals from the pilot pedals 65 and control braking of the wheels 69 of the wheel set 60. The outboard BSCU20 and the inboard BSCU30 receive input from a pilot brake pedal 65. As shown in FIG. 3, pedal input from first pilot brake pedal 65 is received by outside BSCU 20. Pedal input from second pilot brake pedal 65 is received by inboard BSCU 30. Additionally or alternatively, the BSCUs 20, 30 may receive different pedal inputs, such as one input from each pilot for each BSCU20, 30 (e.g., the BSCU20 receives right pedal inputs from both pilots, and the BSCU30 receives left pedal inputs from both pilots).

Each of the outer BSCU20 and the inner BSCU30 receives the first signal directly and the second signal indirectly through the other BSCU20, 30. As shown in FIG. 3, each pilot is provided with two brake pedals 65, such as a left brake pedal 65 and a right brake pedal 65. The pilot pedals 65 may include a first pair of pedals 65 provided for a first pilot (e.g., captain) and a second pair of pedals 65 provided for a second pilot (e.g., captain). The pilot physically manipulates the pedals 65 to generate pilot pedal physical inputs. The physical inputs of both the first and second pilot pedals 65, 65 are measured from their natural positions by sensors or equivalent components and converted into first and second pilot command control signals by transducers or equivalent components. The signal from the first pilot brake pedal 65 is received at the outboard BSCU20 and the signal from the second pilot brake pedal 65 is received at the inboard BSCU 30.

The inboard and outboard BSCUs 20, 30 are configured to receive signals from the brake pedal 65, process the signals, and control valves in the hydraulic system 40. Each of the inside BSCU20 and the outside BSCU30 may be identical and include the same components as shown in fig. 4. Each of the inside BSCU20 and the outside BSCU30 includes processing circuitry 21 (including, but not limited to, one or more microprocessors, microcontrollers, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), and/or other circuitry configured with appropriate software and/or firmware) having one or more general-purpose and/or special-purpose processors that control the various components in accordance with program instructions stored in memory circuitry 22. Memory circuit 22 stores processing logic, programming code, and operational information for use by processing circuit 21. According to various embodiments, the storage circuitry 22 may include volatile memory, non-volatile memory, or both.

Each BSCU20, 30 includes a shared control channel having an independent activation circuit that provides power to a hydraulic activation solenoid to control a shut-off valve 47 within the hydraulic brake system. The circuit may also control backup brake command drivers that are isolation valve driver circuits that select the lesser of the two normal system brake commands.

The input interface 23 is configured to receive pilot inputs through a wired connection, such as a serial port, USB, micro-USB, FIREWIRE, Lightning, and/or Thunderbolt connection. Input interface 23 may also be configured to receive pilot input via radio signals, electrical signals, and/or optical signals. Input interface 23 may also receive signals from one or more other sources, such as a flight controller that monitors the operation of the aircraft. Each BSCU20, 30 may include a digital-to-analog converter 24 to convert the digital enable signal.

As shown in fig. 4, each of the outboard BSCU20 and the inboard BSCU30 initially receives input signals from some of the brake pedals 65. An analog signal based on the received digital signal is sent to the opposing BSCU20, 30, indicating the brake pedal 65 is activated. Digital position signals are also received that indicate the position of the brake pedal 65 and the extent to which the pilot applies the brakes. As shown in fig. 4, each BSCU20, 30 shares an analog enable signal indicating brake pedal activation and a digital position signal indicating the extent to which the pilot has activated the pedals with the other BSCU (20, 30). Thus, each BSCU20, 30 is able to analyze each brake signal.

Each BSCU20, 30 analyzes the inputs and selects the larger of the two pilot pedal inputs. The greater of the two pilot braking commands is selected to apply the greater to the brakes 50 using the first brake module 41 of the hydraulic system 40. The lesser of the two front or rear brake commands is used for backup braking using the backup brake module 42.

As shown in FIG. 3, each BSCU20, 30 includes two independent control channels to control the servo valve 46 in the first brake module 41. The outer BSCU20 includes: a first control channel 91 that pairs the brakes 50 of the pair of front outer wheels 69a, 69 b; and a second control channel 92 that pairs the brakes 50 of the rear outer wheels 69c, 69 d. Likewise, a first control channel 93 from the inboard BSCU30 pairs the brakes 50 of the front inner wheels 69e, 69f, and a second control channel 94 pairs the brakes 50 of the rear inner wheels 69g, 69 h.

Each BSCU20, 30 also includes a shared controlled channel to control backup braking. BSCU20 includes a shared control channel 95 leading to backup brake module 42 and, likewise, BSCU30 includes a shared control channel 96 leading to backup brake module 42.

Fig. 5 illustrates the brake command processing for each BSCU20, 30. The brake pedal command is received by the BSCU20, 30, which determines the greater of the two pilot brake signals (block 180). In the case of a lower slip pressure, the brake pressure is determined based on the angle of pedal deployment (deployment) (block 182). The brake pressure may be determined via a look-up table. The determined brake pressure is then compared to the autobrake pressure command (block 190) and the greater of the two is used to control the first brake module 41 (block 184).

In the case where the brake pressure is higher than the slip pressure, a brake command is generated via a normal anti-slip function. The antiskid command (block 192) causes the brake pressure to be released (block 186) to prevent slippage if a brake command is issued, thereby controlling the first brake module 41.

For backup braking, the lesser of the front and rear braking commands is sent to the shared channel. The shared channel also receives the lesser of the front brake command and the rear brake command from the other BSCU20, 30 (block 194). These signals are sent over the backup control channel to control the backup brake module 42.

The outboard BSCU20 includes a control channel 95 to the backup brake module 42, the control channel 95 controlling the servo valves 46 that control the brakes 50 of the outboard wheels (69a, 69c) of the first wheel set 60 and the servo valves 46 that control the brakes 50 of the outboard wheels (69b, 69d) of the second wheel set 60. The inboard BSCU30 includes a control passage 96 for the servo valve 46 that controls the brakes of the inboard wheels (69e, 69g) of the first wheel set 60 and the brakes 50 of the inboard wheels (69f, 69h) of the second wheel set 60.

As shown in fig. 3, each wheel set 60 of the landing gear shares a first brake module 41. The single first brake module 41 includes a servo valve 46 that controls the braking on each wheel of the wheel set 60.

The hydraulic system 40 as shown in fig. 3 and 6 includes a first brake module 41 and a backup brake module 42. The first brake module 41 is supplied with hydraulic fluid through one or more first lines 43. The backup brake module 42 is supplied with hydraulic fluid through one or more second lines 70. These lines (43, 70) may include separate hydraulic fluid supplies to provide a redundant system in the event of a failure of one portion of the hydraulic system 40. The brake 50 may be supplied with hydraulic fluid by a fault-free supply to ensure braking of the wheels 69.

Line 43 provides hydraulic fluid to the first brake module 41 and line 70 provides hydraulic fluid to the backup brake module 42. A feed line 49 extends from the first brake module 41 to the shuttle valve module. A feed line 75 extends from the backup brake module 42 to a shuttle valve module 80. A feed line 82 extends from the shuttle valve module 80 to the brake 50 of each wheel 69.

The first brake modules 41 each include an outboard portion 44 and an inboard portion 45. The outboard portion 44 includes a servo valve 46 associated with the brake 50 of each outboard wheel 69 of the wheel set 60. The inboard portion 45 includes a servo valve 46 associated with the brake 50 of each inboard wheel 69 of the wheel set 60. The servo valve 46 of the outer section 44 is controlled by the outer BSCU20 and the servo valve 46 of the inner section 45 is controlled by the inner BSCU 30. A fuse (fuse)48 is positioned along line 49 to prevent depletion of the hydraulic system causing downstream leakage. Each of the outer and inner portions 44, 45 includes a shut-off valve 47 to reduce leakage of hydraulic fluid. The shut-off valve 47 also prevents a single solenoid failure from inadvertently braking the wheel 69.

The backup brake module 42 includes a pair of servo valves 46. The first servo valve 46 is associated with a first line 75 through which hydraulic fluid is supplied to the pair of outboard brakes 50, and the second servo valve 46 is associated with a second line 75, the second line 75 supplying hydraulic fluid to the inboard brakes 50. Unlike the first brake module 41, which includes a servo valve dedicated to each brake 50, the backup brake module 42 includes a single servo valve 46 for both brakes 50. For each backup brake module 42, the servo valve 46 associated with the outboard brake 50 is controlled by the outboard BSCU20, and the servo valve 46 associated with the inboard brake 50 is controlled by the inboard BSCU 30. Fuses 48 are positioned along each line 75 to prevent depletion of the hydraulic system causing downstream leakage. The backup brake module 42 may include a shut-off valve 47 to prevent the flow of hydraulic fluid, as shown in FIG. 3.

The shuttle valve module 80 includes a shuttle valve 81 associated with each brake 50. Each shuttle valve 81 connects hydraulic line 49 from first brake module 41 with line 75 from backup brake module 42. Each shuttle valve 81 allows hydraulic fluid to flow from one of the lines (49, 75) through the shuttle valve and into line 82 to control the associated brake 50. Hydraulic sensors 89 that detect fluid pressure may be positioned at various locations along the hydraulic system 40. This may include a pressure sensor 89 located along each line 82, as shown in FIG. 5.

The hydraulic system 40 includes multiple sets of supply lines, each set supplying hydraulic fluid to control braking of one of the wheels 69. Each set of supply lines includes lines 49, 75, 82, and one or more of valves 46, 47, 81. Each set of supply lines also comprises a brake 50 to apply a braking force to one of the wheels 69.

In response to pilot input, the outboard BSCU20 generates brake control signals to control two sets of lines including the valves 46, 47, 81 of the first wheel pair having only the forward outboard wheels 69 and two sets of lines including the valves 46, 47, 81 of the second wheel pair having only the aft outboard wheels 69. The inboard BSCU30 generates brake control signals in response to pilot input to control two sets of lines including the third wheel pair of valves 46, 47, 81 having only the forward inboard wheels 69 and two sets of lines including the fourth wheel pair of valves 46, 47, 81 having only the aft inboard wheels 69.

The braking system 10 is configured to receive braking inputs from a pilot and apply corresponding braking forces. FIG. 7 illustrates a method of braking an aircraft. Initially, a braking input is received from the brake pedal 65 (block 200). The braking input may include input from two or more pilots. Further, the braking inputs may include one or more inputs from each pilot. In the embodiment of FIG. 3, the braking inputs include a pair of inputs from each of the two pilots.

Braking input is received from the pilot at the BSCUs 20, 30. The BSCU20, 30 calculates which pilot input is greater (block 202). The calculation may include: each BSCU20, 30 calculates the degree of each pilot's input based on different pedal inputs. In fig. 3, the calculation includes: the outside BSCU20 determines the degree of input based on a first set of pedal inputs from each pilot and the outside BSCU30 determines the degree of input based on a second set of pilot inputs. BSCUs 20, 30 may share their computations and both determine the maximum input. The determination of the degree of pilot input may also be calculated in other ways.

Once the larger input is determined, BSCU20, 30 uses the larger pilot input to control first brake module 41 to control braking (block 204). For example, if the captain input is greater than the captain, the pilot input is used to control braking using the first braking module 41. The method comprises the following steps: the outboard BSCU20 sends a braking command to the servo valve 46 of the first brake module 41 associated with the outboard wheel 69. The steps further include: the inboard BSCU30 sends a brake command to the servo valve 46 of the first brake module 41 associated with the inboard wheel 69. These commands are used to brake the aircraft.

The lesser of the braking commands between the front and rear wheel pairs is used for backup braking (block 206). The method comprises the following steps: a braking command is sent from BSCU20 to servo valve 46 of backup brake module 42 associated with outboard wheel 69 and a braking command is sent from BSCU30 to servo valve 46 associated with inboard wheel 69.

The braking system described above also provides braking of the aircraft in the event of a failure of one of the BSCUs 20, 30. In this case, the operational BSCUs 20, 30 can control braking to bring the aircraft to a stop.

The brake system 10 may be used in a variety of different aircraft. An aircraft includes a commercial aircraft including a plurality of rows of seats, each seat configured to receive a passenger. Other aircraft include, but are not limited to, manned aircraft, unmanned aircraft, manned spacecraft, unmanned spacecraft, manned rotorcraft, unmanned rotorcraft, satellites, rockets, missiles, manned ground vehicles, unmanned ground vehicles, and combinations thereof.

The present disclosure may be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the disclosure. The present aspects are to be considered as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

Moreover, the present disclosure includes embodiments according to the following clauses:

clause 1. a braking system (10) for a dual-landing-gear aircraft including left and right landing gears each having forward and aft inboard wheels and outboard wheels, the braking system comprising:

an outboard brake system control unit (20) including at least a first processing circuit (21) that generates brake control signals in response to pilot input to symmetrically control braking of a first wheel pair including only the front outboard wheel (69) and a second wheel pair including only the rear outboard wheel (69);

an inboard brake system control unit (30) including at least a second processing circuit (21) responsive to the pilot input to generate brake control signals to symmetrically control braking of a third wheel pair including only the front inboard wheel (69) and a fourth wheel pair including only the rear inboard wheel (69), the inboard brake system control unit (30) being independent of the outboard brake system control unit (20); and

a hydraulic system (40) that applies a braking force to the wheels (69) in response to the brake control signal.

Clause 2. the braking system of clause 1, wherein: the outboard brake system control unit (20) sends the brake control signal along a first control channel (91) to brake only the forward outboard wheels (69) of both the left and right landing gears, and sends the brake control signal along a second control channel (92) to brake only the rear outboard wheels (69) of both the left and right landing gears, the first control channel (91) being independent of the second control channel (92).

Clause 3. the braking system of clause 2, wherein: the inboard brake system control unit (30) sends the brake control signal along a third control channel (93) to brake only the forward inner wheels (69) of both the left and right landing gears, and sends the brake control signal along a fourth control channel (94) to brake only the rear inner wheels (69) of both the left and right landing gears, the third control channel (93) being independent of the fourth control channel (94).

Clause 4. the braking system of clause 1, wherein: the inboard brake system control unit (20) and the outboard brake system control unit (30) further include an input interface (23) that receives the pilot input, which includes separate first and second inputs.

Clause 5. the braking system of clause 1, wherein: the hydraulic system (40) comprises:

a first hydraulic line (49) and a backup line (75) supplying hydraulic fluid to the brakes (50) at the wheels (69);

a servo valve (46) located along the first hydraulic line (49) and the backup line (75), the servo valve regulating pressure of hydraulic fluid supplied to the brakes (50) in response to the brake control signals received from the inboard brake system control unit (20) and the outboard brake system control unit (30);

a shuttle valve (81) operatively connecting the first hydraulic line (49) and the backup line (75), the shuttle valve (81) supplying hydraulic fluid from one of the first hydraulic line (49) and the backup line (75).

Clause 6. the braking system of clause 5, wherein: each servo valve (46) located along the first hydraulic line (49) regulates pressure to one of the brakes (50), and a servo valve (46) located along the backup supply line (75) regulates a pair of brakes (50) on one of the left and right landing gears.

Clause 7. the brake system of clause 5, further comprising: a first module (41) housing each servo valve (46) regulating the pressure of hydraulic fluid along the first hydraulic line (49) to a brake (50) of one of the left and right landing gears; and a second module (42) housing each servo valve (46) regulating the pressure of hydraulic fluid along the second hydraulic line (75) to the brakes (50) of the other of the left and right landing gears.

Clause 8. the braking system of clause 7, wherein: each of the first and second modules (41, 42) includes a shut-off valve (47) that reduces leakage of hydraulic fluid.

Clause 9. the braking system of clause 5, wherein: the outboard brake system control unit (20) controls a servo valve (46) that supplies hydraulic fluid to each of the front and rear outboard wheels (69), and the inboard brake system control unit (30) controls a servo valve (46) that supplies hydraulic fluid to each of the front and rear inboard wheels (69).

Clause 10. an aircraft having the brake system (10) according to clause 1.

Clause 11. a braking system (10) for a dual-landing-gear aircraft including left and right landing gears each having forward and aft inboard wheels and outboard wheels, the braking system comprising:

a hydraulic system (40) comprising a plurality of sets of supply lines (49, 75, 82) each supplying hydraulic fluid to control braking of one of the wheels (69), each of the plurality of sets of supply lines (49, 75, 82) comprising:

a plurality of valves (46, 47, 81);

a brake (50) that applies a braking force to one of the wheels (69);

an outboard brake system control unit (20) including first processing circuitry (21) responsive to pilot input to generate brake control signals to control valves (46, 47, 81) of a first wheel pair including only the forward outboard wheels (69) and valves (46, 47, 81) of a second wheel pair including only the aft outboard wheels (69); and

an inboard brake system control unit (30) comprising second processing circuitry (21) that generates brake control signals to control valves (46, 47, 81) of a third wheel pair comprising only the front inboard wheels (69) and valves (46, 47, 81) of a fourth wheel pair comprising only the rear inboard wheels (69);

the outboard (20) and inboard (30) brake system control units receive pilot input and control valves (46, 47, 81) of each of the wheel pairs (69) to apply a symmetric braking force to the wheels (69) of each of the wheel pairs.

Clause 12. the brake system of clause 11, further comprising:

a first control passage (91) extending between the outboard brake system control unit (20) and one of the valves (46) on one of the supply lines (49) of the front outboard wheel (69);

a second control passage (92) extending between the outboard brake system control unit (30) and one of the valves (46) on one of the supply lines (49) of the rear outboard wheel (69);

a third control passage (93) extending between the inboard brake system control unit (30) and one of the valves (46) on one of the supply lines (49) of the front inboard wheels (69); and

a fourth control passage (94) extending between the inboard brake system control unit (30) and one of the valves (46) on one of the supply lines (49) of the rear inboard wheel (69);

each of the first control passage (91), the second control passage (92), the third control passage (93), and the fourth control passage (94) is independent of each other.

Clause 13. the braking system of clause 11, wherein: the hydraulic system (40) includes a first hydraulic supply line (43) and a backup hydraulic supply line (70), and each of the supply lines (43, 70) further includes a shuttle valve (81) that selectively delivers the hydraulic fluid to the brake (50) from one of the first hydraulic supply line (43) and the backup hydraulic supply line (70) based on the pilot input.

Clause 14. the braking system of clause 11, wherein: each of the inboard brake system control unit (20) and the outboard brake system control unit (30) receives pilot inputs from both a first pilot and a second pilot.

Clause 15. a method of braking an aircraft, the method comprising the steps of:

receiving pilot input at both an outboard brake system control unit (20) and an inboard brake system control unit (30);

sending a first brake signal from the outboard brake system control unit (20) based on the pilot input and symmetrically braking a first pair of forward outboard wheels (69) of right and left landing gears and a second pair of aft outboard wheels (69) on the right and left landing gears; and

based on the pilot input, sending a second brake signal from the inboard brake system control unit (30) and symmetrically braking a third pair of front inboard wheels (69) of the right and left landing gears and a fourth pair of rear inboard wheels (69) on the right and left landing gears.

Clause 16. the method of clause 15, further comprising the steps of: -sending the first braking signal from the outside brake system control unit (20) to the first pair of front outside wheels (69) via a first control channel (91), and-sending the first braking signal from the outside brake system control unit (20) to the second pair of rear outside wheels (69) via an independent second control channel (92).

Clause 17. the method of clause 16, further comprising the steps of: sending the second brake signal from the inboard brake system control unit (30) to the third pair of front inner wheels (69) via a third control channel (93), and sending the second brake signal from the inboard brake system control unit (30) to the fourth pair of rear inner wheels via an independent fourth control channel (94).

Clause 18. the method of clause 15, further comprising the steps of: determining a greater of first and second inputs from the pilot input, and based on the greater of the first and second inputs, sending the first braking signal from the outboard brake system control unit (20) to symmetrically brake the first and second pairs of outboard wheels (69), and based on the greater of the first and second inputs, sending the second braking signal from the inboard brake system control unit (30) to symmetrically brake the third and fourth pairs of inboard wheels (69).

Clause 19. the method of clause 18, further comprising the steps of: determining a lesser of the braking commands between the front and rear pairs of wheels from the pilot input, and controlling backup braking based on the lesser of the braking commands between the front and rear pairs of wheels.

Clause 20. the method of clause 15, further comprising the steps of: the braking signal is sent to a servo valve (46) and the flow of hydraulic fluid is regulated to regulate braking of the plurality of pairs of brakes (50).