The evolution of fighter aircraft flight control technology is briefly surveyed. Systems engineering, battle damage considerations for adaptive flutter suppression, in-flight simulation, and artificial intelligence are briefly discussed

Nelson, W. E., Jr.

English

NASA Technical Reports Server

FIGHTER AIRCRAFT FLIGHT CONTROL TECHNOLOGY 
DESIGN REQUIREMENTS 
W. E. Nelson, Jr. 
Northrop Corporation, Aircraft Division 
Hawthorne, California 
First Annual NASA Aircraft Controls Workshop 
NASA Langley Research Center 
Hampton, Virginia 
October 25-27, 1983 
549 
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https://ntrs.nasa.gov/search.jsp?R=19840012529 2020-03-22T08:18:27+00:00Z
This figure represents the evolution of control technology. As we compare the 
current day fighters with the Wright brothers' airplane, we notice that they 
had achieved control technology and mastered their applications without electronics. 
But the future demands further emphasis of pursuing the aspects of control,with 
the extension of research going into exotic concepts such as vortex management. 
550 
Truly, the day of the pilot controlling the aircraft will diminish. As weapon 
system integration and flight path and navigational integration become more heavily 
automated, the pilot will become a manager. His primary task will be selecting 
the right functional requirements; his secondary task will be as backup. He will 
act in the fashion he presently performs, that of a pilot. 
551 
This figure humorously depicts the challenge the future pilot will have. 
However, it is not unattainable, as work on the AFT1 and the present F-18 has 
demonstrated. The research needed is to establish standards that the designer 
can utilize to evaluate his concepts. 
552 
Active control elements in flight control technology encompass many technical 
disciplines. Electronic chip development will result in achieving potential 
architectures of control laws operating in real time during flight. The high 
densities and improved computation times will allow greater design flexibility for 
fault-tolerant applications. Data communications, actuation technology, and 
electrical power concept, when combined with the elements of the computer, will 
lead to the indicated technology objectives. 
553 
Flight control technology has evolved to a total systems engineering discipline 
as depicted in this figure. The mission requirements set the needs. The 
available electronic technology provides the capability. The interface with all 
avionic and other aircraft subsystems increases the flexibility of the control 
capability. But hidden inside the effort is an item that can deter the design 
performance, the validation testing. Thus, a need exists for desiqn standards 
to relate the desired methods and procedures to be used in the design effort of 
future vehicles. 
554 
Here is a specific example of a control application that is in its infancy. The 
payoff on potential aircraft can be related into reduced structural weight. 
However, further research is needed to explore various concepts and to demonstrate 
them in both wind tunnel and flight tests. 
BATTLE DAMAGE CONSIDERATIONS 
FOR ADAPTIVE FLUTTER SUPPRESSION 
a SUSTAIN FLUTTER FREE MRATlDU 
FOLLOWINQ AN ARRAY OF BATTLE DAMAOE 
STATES 
l ENHANCE THE EXIttIm) ADAPTIVE 
ALGORITHM BY SELF-REPAIRIMB CowCEm 
‘AYOFF 
1 
p&q 
l IMPROVED COMBAT EFFECTIVENESS l DEVELOP ALDORITHMS FOR BATTLE DAMAQE 
l RAPID BATTLE DAMAGE REPAIR - DETECTION - VOTINQ 8CHEME 
l REDUCED PEACE TIME COST - ISOLATION - VARIANCE COMTARIW 
- CONTROL RECONFlDURATlON - 
REDUNDANTCONTROLSUBFACE 
-------------- OPERATION 
l EMPHASIS DN Y F-17 WIND TUNNEL TEST 
MODEL 
l INCREASED SOFTWARE COMPLEXITY 
l COMPUTATIONAL (FRAME TIME) PENALTY 
l CREW INTERFACE ISSUES 
555 
The role of "in-flight simulation" needs to,be revived. This area is valuable 
to relate new design features of control law, systems operation, and interaction 
with the pilot in a near real-life environment. and to reflect the needed design 
changes into the new vehicle before a large change impact of cost and schedule is 
imposed on the project. A new airframe platform is needed to replace the antiquated 
T-33. 
FUTURE FLIGHT CONTROL SYSTEM NEEDS - IMPROVED IN-FLIGHT SIMUIATION 
0 VARIETY OF HANDLING QUALITIES ISSUES NEED FURTHER STUDY - 
LATERAL SENSITIVITY, CONTROL HARMONY, PILOT MODES, CRITERIA 
0 AVIONICS/PROPULSION I TEGRATION REQUIRE FLIGHT INVESTIGATION 
0 HIGH "G" CAPABILITY REQUIRED 
0 SOFTWARE INTENSE SYSTEMS REQUIRED 
556 
I 
"Artificial intelligence" (AI) is now the term used to mean what we once referred 
to as computer capability. However, much effort needs to be applied in this 
area to determine the best approaches and resulting payoffs in using the AI 
concept during real-time computer operation. The figure indicates examples of 
applications. 
APPLICATION OF AI METHODS TO FCS AND AIRCRAFT TECHNOLOGIES 
(NEAR AND LONG TERM) 
PVI, PILOT DECISION AIDIWG, PILOT AS SYSTEM MANAGER 
FAULT-TOLERANT COMPUTING (REAL TIME) 
ANALYSIS/SYNTHESIS PROGRAM (NON-REAL TIME) 
INTEGRATED PROPULSION/CONTROL SYSTEMS 
ADAPTIVE CONTROLLERS 
OPTIMIZATION WITH REGARD TO HANDLING QUALITIES, TERRAIN 
FOLLOWING AND AVOIDANCE, TURBULENCE, FLUTTER SUPPRESS ION 
AND LOAD ALLEVIATION, ETC, 
"SUPER-MANEUVERABLE" AIRCRAFT 
AVIONICS 
ROBOT KS 
MANUFACTURING 
QUALITY ASSURANCE AND CONTROL 
INDUSTRIAL CONTROL 
FACTORY OF-THE FUTURE 
557 


Fighter aircraft flight control technology design requirements

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