The Boeing Company

Abhijit J Chakravarty

Chuong B Tran

Yoshiki Nakamura

Dagfinn Gangsaas

Steven R Cooper

John B Moore

John K Ho

An onboard flight management system produces cost-effective trajectory target signals in response to an input desired time of arrival. Aircraft monitoring systems produce signals corresponding to real-time aircraft parameters including fuel flow rate, airspeed, windspeed, thrust, drag and mass. Stored in memory are aircraft characteristics including time cost, fuel cost, and acceleration due to gravity. A flight computer responds to an input desired time-of-arrival and the real-time parameters and stored characteristics signals and produces cost-effective trajectory target signals. The computer employs multiply regressed drag and fuel flow models which avoid trajectory discontinuities and the trajectory targets are produced using a Fibonacci search technique, which is computationally very efficient.

Time-responsive flight optimization system

A failure analysis system for simulating the effect of a subsystem failure in an electronic system. The failure analysis system includes a knowledge base, a user interface, and a failure analysis component. The knowledge base simulates the electronic system in a variety of operating configurations related to the status of a source selection switching mechanism and/or different system modes. The user interface receives simulation condition data that identifies an operating configuration and failure data identifying at least one subsystem failure. The failure analysis component simulates the propagation of the subsystem failure effect through the electronic system by analyzing the failure data in accordance with the knowledge base and the simulation condition data, and generates a set of subsystem failure responses that would occur in the electronic system if the failure actually occurred. The failure analysis system also performs a fault isolation analysis. The user interface receives response data identifying a failure response. The failure analysis component identifies the source of the failure response in the electronic system by backtracking the failure response data in accordance with the knowledge base and the simulation condition data. One or more possible subsystem sources of the failure response identified by the failure response data are identified.

Failure analysis system

Accelerations due to excitation of the natural modes of an aircraft's body are suppressed by an active suppression system. Dedicated accelerometers are positioned in the aircraft at optimal locations for sensing modal induced lateral accelerations. The accelerometer produced signals are processed through control logic which, in response thereto, and in response to aircraft velocity and altitude related signals produces output control signals. The control signals effect rudder deployment creating forces to suppress the natural mode induced accelerations.

Aircraft modal suppression system

An output vector produced by a plant in response to an input vector is filtered by a plurality of bandpass filters, each filter having a different pass band. A filtered output vector from each filter is provided as input to a separate adaptive feedback controller, and feedback vectors produced by the separate controllers are summed to provide the input vector to the plant. Each adaptive feedback controller continuously identifies an open-loop transfer function of the plant characterizing a particular frequency band of plant operation, and continuously adjusts its own open-loop transfer function so that the poles of the closed-loop transfer function of the plant for that particular frequency mode of operation are assigned to constant stable values despite changes in the open-loop transfer function of the plant.

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Renton, WA, United States of America

Abhijit J Chakravarty