Intelligent Flight Control System

The Intelligent Flight Control System (IFCS) is a next-generation flight control system designed to provide increased safety for the crew and passengers of aircraft as well as to optimize the aircraft performance under normal conditions.ref|NASA The main benefit of this system is that it will allow a pilot to control an aircraft even under failure conditions that would normally cause it to crash. The IFCS is being developed under the direction of the NASA Dryden Flight Research Center with the collaboration of the NASA Ames Research Center, Boeing Phantom Works, the Institute for Scientific Research at West Virginia University, and the Georgia Institute of Technology.

Objectives of IFCS

The main purpose of the IFCS project is to create a system for use in civilian and military aircraft that is both adaptive and fault tolerant.ref label|NASA|1|a This is accomplished through the use of upgrades to the flight control software that incorporate self-learning neural network technology. The goals of the IFCS neural network project are.ref|FlightTest
# To develop a flight control system that can identify aircraft characteristics through the use of neural network technology in order to optimize aircraft performance.
# To develop a neural network that can train itself to analyze the flight properties of the aircraft.
# To be able to demonstrate the aforementioned properties on a modified F-15S/MTD aircraft during flight, which is the testbed for the IFCS project.

Theory of Operation

The neural network of the IFCS learns flight characteristics in real time through the aircraft’s sensors and from error corrections from the primary flight computer, and then uses this information to create different flight characteristic models for the aircraftref|IFCS. The neural network only learns when the aircraft is in a stable flight condition, and will discard any characteristics that would cause the aircraft to go into a failure condition. If the aircraft’s condition changes from stable to failure, for example, if one of the control surfaces becomes damaged and unresponsive, the IFCS can detect this fault and switch the flight characteristic model for the aircraft. The neural network then works to drive the error between the reference model and the actual aircraft state to zero.

Project History

Generation 1

Generation 1 IFCS flight tests were conducted in 2003 to test the outputs of the neural network.ref label|NASA|1|b In this phase, the neural network was pre-trained using flight characteristics obtained for the F-15S/MTD in a wind tunnel test and did not actually provide any control adjustments in flight.ref label|FlightTest|2|a The outputs of the neural network were run directly to instrumentation for data collection purposes only.

Generation 2

Generation 2 IFCS tests were conducted in 2005 and used a fully integrated neural network as described in the theory of operation.ref label|IFCS|3|a It is a direct adaptive system that continuously provides error corrections and then measures the effects of these corrections in order to learn new flight models or adjust existing ones.ref label|NASA|1|c To measure the aircraft state, the neural network takes 31 inputs from the roll, pitch, and yaw axes and the control surfaces.ref label|IFCS|3|b If there is a difference between the aircraft state and model, the neural network adjusts the outputs of the primary flight computer through a dynamic inversion controller to bring the difference to zero before they are sent to the actuator control electronics which move the control surfaces.

References

#note label|NASA|1|anote label|NASA|1|bnote label|NASA|1|ccite web
title=NASA Dryden Flight Research Center Fact Sheets: Intelligent Flight Control System
work=
url=http://www.nasa.gov/centers/dryden/news/FactSheets/FS-076-DFRC.html
publisher=NASA Dryden Flight Research Center
date= July 21, 2006
accessdate=2007-02-25
#note label|FlightTest|2|acite web
title=Flight test of an intelligent flight-control system
work=
url=http://findarticles.com/p/articles/mi_qa3957/is_200310/ai_n9342664
publisher=Associated Business Publications
month= October | year= 2003
accessdate=2007-02-25
#note label|IFCS|3|anote label|IFCS|3|bcite paper
author=Peggy S. Williams-Hayes
title=Flight Test Implementation of a Second Generation Intelligent Flight Control System
publisher=NASA Dryden Flight Research Center
date= August 25, 2005
url=http://dtrs.dfrc.nasa.gov/archive/00000461/01/213669.pdf

See also

* Aircraft flight control systems
* F-15
* F-15S/MTD