Abstract: A brake control system includes a servo valve and a brake control unit in electronic communication with the servo valve. The servo valve is configured to receive a hydraulic fluid and provide the hydraulic fluid to apply braking force to a wheel via a hydraulic line. The brake control unit is configured to calibrate the servo valve and determine whether a calibration of the servo valve was successful. In response to the calibration of the servo valve being successful, the brake control unit can operate the servo valve in an open-loop system. In response to the calibration of the servo valve being unsuccessful, the brake control unit can operate the servo valve in a closed-loop system.

Abstract: A brake control system of the present disclosure calibrates a servo valve and calculates a calibrated transfer function associated with the servo valve for precise braking in open-loop mode. The calibration steps may include determining i) whether an aircraft is on a ground surface, ii) whether the aircraft is not moving relative to the ground surface, and iii) whether braking is applied to a brake system of the aircraft. The brake control unit may calibrate the servo valve in response to the brake control unit determining that i) the aircraft is on the ground surface, ii) the aircraft is not moving relative to the ground surface, and iii) the braking is not applied to the brake system of the aircraft. The calibration process includes sending two or more test currents to the servo valve, and determining braking pressures associated with those test currents to calculate the transfer function.

Abstract: A braking system is disclosed. In various embodiments, the brake system includes a brake assembly; a hydraulic braking subsystem having a hydraulic brake actuator configured to operate the brake assembly; and an electric braking subsystem having an electric brake actuator configured to operate the brake assembly.

Abstract: A method of taxiing an aircraft may comprise determining, via a controller, whether the aircraft is taxiing with fewer brakes active than a total number of brakes; and modifying, via the controller, a brake pressure supplied to an active brake of the aircraft as a function of pedal deflection in response to determining the aircraft is taxiing with fewer brakes active relative to the total number of brakes.

Abstract: A method of taxiing an aircraft may comprise: determining, via a brake controller, whether the aircraft is taxiing with a first thrust provided from a first side of the aircraft, a second thrust from a second side of the aircraft, or both the first thrust and the second thrust; and modifying, via the brake controller, a first brake pressure supplied to a first brake disposed on the first side of the aircraft as a function of pedal deflection in response to the taxiing with the first thrust only.

Abstract: A valve assembly may comprise: a housing defining an inlet port, an outlet port, a solenoid valve inlet port, and a solenoid valve outlet port, the inlet port in fluid communication with the solenoid valve inlet port; a shutoff valve disposed in the housing, the shutoff valve including a shutoff valve inlet port in fluid communication with the inlet port and a shutoff valve outlet port in fluid communication with the outlet port, and a second shutoff valve inlet port in fluid communication with the solenoid valve outlet port; a filter disposed downstream of the valve inlet port; and a check valve disposed between the shutoff valve outlet port and the outlet port of the housing.

Abstract: Systems and methods for shut off valve failure detection are provided. The system may comprise a housing, a shut off valve disposed within the housing, a first servovalve and a second servovalve coupled to the housing, and a pressure sensor disposed within the housing in fluid communication with the shut off valve. A controller may receive a pressure signal from the pressure sensor in the system, and a brake signal from a brake input device. The controller may determine whether there has been a shut off valve failure in the system in response to the pressure signal being greater than a pressure threshold and the controller failing to receive the brake signal, for a threshold period. The controller may then send a signal to a notification system in response to detection of the shut off valve failure and output a shut off valve failure notification.

Abstract: A method for detecting an erroneous velocity data using a controller in communication with a velocity sensor onboard a vehicle includes receiving a time-series velocity data from the velocity sensor, calculating a time-series acceleration data using the time-series velocity data, calculating a time-series jerk data using the time-series acceleration data, calculating a saturated (numerically bounded) jerk data using the time-series jerk data, calculating an estimated acceleration data using the saturated jerk data, calculating a difference between the estimated acceleration data and the time-series acceleration data, and determining whether the difference is greater than a threshold value. The erroneous velocity data is detected in response to the difference being greater than the threshold value.

Abstract: An autobrake system includes a brake control unit (BCU), and a control knob in electronic communication with the BCU. The BCU is configured to receive a position signal from the control knob, the position signal corresponding a position of the control knob. The BCU is configured to select a braking deceleration based upon the position signal, wherein the braking deceleration continuously changes between a minimum braking deceleration and a maximum deceleration in response to the control knob moving between a first position and a second position for fine tuning of the braking deceleration.

Abstract: A braking system for an aircraft is disclosed herein. The braking system may comprise: a brake assembly; a hydraulic braking subsystem having a hydraulic brake actuator configured to operate the brake assembly; an electric braking subsystem and a hydraulic braking subsystem. During a flight, one of the electric braking subsystem and the hydraulic braking subsystem may be selected as a primary braking system. The braking system may be configured to command braking of a brake assembly by the hydraulic braking subsystem and the electric braking subsystem during an RTO phase of the flight. The braking system may be configured to command braking of a brake assembly by a secondary braking system in response to a failure of a primary braking system during the RTO phase of the flight.

Abstract: A braking system for an aircraft may comprise: a brake assembly; a hydraulic braking subsystem having a hydraulic brake actuator configured to operate the brake assembly; an electric braking subsystem having an electric brake actuator configured to operate the brake assembly and a load cell configured to measure a force supplied by the electric brake actuator; a hydraulic brake control unit configured to control the hydraulic braking subsystem; and an electric brake control unit configured to control the electric braking subsystem, the electric brake control unit in operable communication with the hydraulic brake control unit, the electric brake control unit configured to calibrate the load cell by a scale factor based on a measured force from the load cell, a measured hydraulic pressure used to exceed the measured force received from the hydraulic brake control unit, and a piston area of the hydraulic brake actuator.

Abstract: Systems and methods for antiskid brake control include a brake control unit (BCU) configured to generate a brake command signal adjusted for a wide range of brake coefficient of friction based upon a real-time aircraft kinetic energy value. A method for antiskid brake control includes receiving, by a BCU, an aircraft mass and a wheel speed signal. The BCU determines an aircraft speed based upon the wheel speed signal and calculates the aircraft kinetic energy using the aircraft speed and aircraft mass. One or more antiskid parameters (e.g., proportional gain, a derivative gain, and/or deceleration target value) are adjusted based upon the aircraft kinetic energy to generate, by the brake control unit, an optimal antiskid brake command signal.

Abstract: A brake control system of the present disclosure includes an accelerometer coupled to an axle. A brake control unit is configured to receive an axle acceleration signal indicative of an axle acceleration from the accelerometer, and decrease a braking command pressure in response to the axle acceleration being greater than a threshold acceleration value.

Abstract: A braking system includes a brake stack; a first brake cavity operably coupled to the brake stack, the first brake cavity including a first plurality of brake actuators; a second brake cavity operably coupled to the brake stack, the second brake cavity including a second plurality of brake actuators; and a brake control module, the brake control module being configured to activate either the first plurality of brake actuators or both the first plurality of brake actuators and the second plurality of brake actuators in response to an input brake load.

Abstract: A braking system for an aircraft may comprise: a brake assembly including a brake stack; an electric braking subsystem having an electric brake actuator configured to operate the brake assembly; and a controller in operable communication with the electric braking subsystem, the controller configured to perform a wear depth measurement process, the wear depth measurement process comprising: determine a reference position of the electric brake actuator; command the electric brake actuator to extend toward the brake stack; receive a force measurement from a load cell in response to the electric brake actuator contacting the brake stack; determine a linear travel distance of the electric brake actuator based on an end position determined from the force measurement; and determine a wear depth based on calculating a difference between the linear travel distance and a prior linear travel distance of the electric brake actuator.

Abstract: A braking system for an aircraft may comprise: a brake assembly; a hydraulic braking subsystem having a hydraulic brake actuator configured to operate the brake assembly; an electric braking subsystem having an electric brake actuator configured to operate the brake assembly and a load cell configured to measure a force supplied by the electric brake actuator; a hydraulic brake control unit configured to control the hydraulic braking subsystem; and an electric brake control unit configured to control the electric braking subsystem, the electric brake control unit in operable communication with the hydraulic brake control unit, the electric brake control unit configured to calibrate the load cell by a scale factor based on a measured force from the load cell, a measured hydraulic pressure used to exceed the measured force received from the hydraulic brake control unit, and a piston area of the hydraulic brake actuator.

Abstract: A braking system for an aircraft is disclosed herein. The braking system may comprise: a brake assembly; a hydraulic braking subsystem having a hydraulic brake actuator configured to operate the brake assembly; an electric braking subsystem and a hydraulic braking subsystem. During a flight, one of the electric braking subsystem and the hydraulic braking subsystem may be selected as a primary braking system. The braking system may be configured to command braking of a brake assembly by the hydraulic braking subsystem and the electric braking subsystem during an RTO phase of the flight. The braking system may be configured to command braking of a brake assembly by a secondary braking system in response to a failure of a primary braking system during the RTO phase of the flight.

Abstract: A method for detecting an erroneous velocity data using a controller in communication with a velocity sensor onboard a vehicle includes receiving a time-series velocity data from the velocity sensor, calculating a time-series acceleration data using the time-series velocity data, calculating a time-series jerk data using the time-series acceleration data, calculating a saturated (numerically bounded) jerk data using the time-series jerk data, calculating an estimated acceleration data using the saturated jerk data, calculating a difference between the estimated acceleration data and the time-series acceleration data, and determining whether the difference is greater than a threshold value. The erroneous velocity data is detected in response to the difference being greater than the threshold value.

Abstract: A method of taxiing an aircraft may comprise determining, via a controller, whether the aircraft is taxiing with fewer brakes active than a total number of brakes; and modifying, via the controller, a brake pressure supplied to an active brake of the aircraft as a function of pedal deflection in response to determining the aircraft is taxiing with fewer brakes active relative to the total number of brakes.

Abstract: An emergency park brake system of an aircraft may include an electrical power interface, an electromechanical actuator, and a hydraulic brake valve. The electrical power interface may be configured to receive electrical power from a power source. The electromechanical actuator may be in selective power receiving communication with the electrical power interface and the electromechanical actuator may be mechanically coupled to and configured to selectively actuate the hydraulic brake valve. The electrical connection between the electromechanical actuator and the electrical power interface may be based on an emergency braking input.