The Boeing Company

Thomas Todd Griffith

David T Yamamoto

John J Gowan

Scott Brandon Kanemori

Bruce Lam

Nima Forghani

Jean Marie Crane

Erik L Godo

Trent Daryl Miller

Bechara J Mallouk

Richard L Campbell

Tu-Luc H Nguyen

John David Anderson

Jay S Kallaher

Michael Gian Catalfamo

Marisa R Jenkins

Joseph Michael Wapenski

An automatic braking system controller automatically decelerates an aircraft on a runway according to a brake-to-exit or a constant deceleration function. The automatic braking system controller determines whether the aircraft can decelerate to a selected velocity prior to reaching a target location along the runway. In response to determining that the aircraft can decelerate to the selected velocity prior to reaching the target location, the automatic braking system controller automatically decelerates the aircraft with a comfortable deceleration profile such that the aircraft reaches the selected velocity at the target location.

Automatic braking system controller

A system, method, and apparatus for brake load alleviation amongst at least one first brake and at least one second brake is disclosed. The method involves sensing an amount of brake pedal application in response to engagement of at least brake pedal. The method further involves determining whether the amount of brake pedal application is greater than a brake pedal application threshold value. Also, the method involves generating a brake application profile, when it is determined that the amount of brake pedal application is greater than the brake pedal application threshold value. The brake application profile indicates that actuation of at least one first brake is delayed by a first time delay, and that actuation of at least one second brake is delayed by a second time delay. Further, the method involves actuating at least one first brake and at least one second brake according to the brake application profile.

Brake load alleviation functions

Systems, methods, and apparatus for optimizing real-time antiskid control initialization for a vehicle on a travel surface are disclosed. In one or more embodiments, a method involves determining when at least one wheel of the vehicle touches ground. The method further involves calculating a rate of wheel spin up for at least one wheel. Also, the method involves determining whether the rate of wheel spin up exceeds a wheel spin up rate threshold. In addition, the method involves applying a high level of brake force when the rate of wheel spin up exceeds the wheel spin up rate threshold, and applying a low level of brake force when the rate of wheel spin up does not exceed the wheel spin up rate threshold.

Optimized real-time antiskid control initialization for travel surfaces as a function of wheel spinup

A system and method for determining a predicted stopping performance of an aircraft moving on a runway. A predicted stopping force acting on the aircraft to stop the aircraft is determined by a processor unit as the aircraft is moving on the runway. A predicted deceleration of the aircraft moving on the runway is determined by the processor unit using the predicted stopping force acting on the aircraft to stop the aircraft. The predicted stopping performance of the aircraft on the runway is determined by the processor unit using the predicted deceleration of the aircraft.

Aircraft stopping performance display and warning

A low-speed antiskid control for a multigain hydraulic valve brake system for an airplane is disclosed. The antiskid control includes low- and high-pressure bias modulation (PBM) high step thresholds. At high speeds the low PBM threshold is used to control a PBM high step firing. At low speeds, the high PBM threshold is used to prevent a PBM high step firing unless a deep skid is occurring. The use of a high threshold at low airplane speeds prevents a low speed control loss due to PBM high step firing reducing brake pressure to below minimum brake contact pressure.

Low-speed antiskid control for multigain hydraulic valve brake system

At low speeds, an antiskid/autobrake control system applies a brake release current to the antiskid valves of the brake system associated with selected wheels of an airplane to prevent brake shudder caused by gear walk. The control system obtains a measured wheelspeed value from each of the selected wheels and calculates a reference wheelspeed based the measured wheelspeed. Tests are made to determine if the reference wheelspeed is below some predetermined magnitude, e.g., 15 knots, and if the airplane ground speed is below some predetermined magnitude, e.g., 50 knots. If the tests are passed, the value of a low-speed brake release current to be applied to the antiskid valves of the airplane's brake system is determined. In order to prevent an abrupt change in braking, the low-speed brake release value ramps off as the airplane slows to a stop. Releasing some of the brakes results in the pilot increasing pressure on the remaining brakes, thereby eliminating brake shudder due to gear walk. Preferably, the low-speed brake release signal is only generated if a valid wheelspeed value has been detected in a predetermined period of time, e.g., 0.5 seconds. Further, a low-speed brake release current is generated only if the low-speed brake release current is greater than an antiskid control current.

Antiskid/autobrake control system with low-speed brake release to reduce

An aircraft autobrake system utilizes a hydraulic fluid pressure sensor to provide a signal proportional to brake hydraulic fluid pressure magnitude to a control system. The control system uses closed loop feedback of this pressure signal to control autobrake application. Such control avoids pressure or deceleration overshoot or undershoot caused by not achieving brake stack closure when deceleration control is applied. Upon landing, if autobrake control command plus the change in autobrake control command necessary to eliminate deceleration error is less than a specified minimum, then brake stack closure needs to be maintained. In that case, the control system determines hydraulic fluid pressure error and adjusts hydraulic fluid pressure to eliminate such pressure error, using closed loop feedback. Upon elimination of pressure error, indicating brake stack closure, deceleration control then applies autobraking to slow the aircraft without pressure or deceleration overshoot or undershoot. If upon landing, the autobrake control command plus the change in autobrake control command necessary to eliminate deceleration error is greater than a specified minimum, then deceleration control is used to apply braking and decelerate the aircraft.

Method to maintain brake stack closure during autobrake application

What follows is a description of a three track mechanism assembly for a vehicle door, and in particular for a light rail vehicle door. Each track mechanism includes a guide rail for guiding the door in its opening and closing movement relative to the vehicle body. Two of the track mechanisms include actuators for producing the opening and closing movement of the door. One of these actuators produces the desired longitudinal displacement of the door relative to the vehicle body, while the other actuator produces the desired transverse displacement of the door relative to the vehicle body. In addition, an extraction device can be included with the track mechanism having the actuator producing the desired longitudinal displacement for assisting the other actuator in producing the desired transverse displacement of the door relative to the vehicle body. The same two track mechanisms which include the noted actuators also serve to transfer the door weight to the vehicle body, each transferring a part of the door weight.

Growing community of inventors

Seattle, WA, United States of America

Thomas Todd Griffith