1.0 Introduction3.0 Model for F14 Jet aircraftFigure 7: Stick InputAlpha (Rad)3.0 Design requirements For the Pitch Controller3.1 Transfer function3.3 Matlab representation and open-loop response3.2 PID Controller3. Fundamentals of Active Aeroelastic Wing (AAW)Figure 1 shows the functionality of the aeroelastic wing.[2]http://www.nasa.gov/centers/dryden/news/FactSheets/FS-061-DFRC.html[3]http://www.engin.umich.edu/group/ctm/examples/pitch/digPCSS.html[4]Modeling Aircraft Wing loads from Flight data using Neural Networks www.dfrc.nasa.gov/DTRS/2003/PDF/H-2546.pdf[6]http://www.simlabs.arc.nasa.gov/vms/controls.html[7] MATLAB toolboxActive Aeroelastic Wing Sarah ChandrasekarDepartment of Engineering, Calvin CollegeEngineering 315 Final PaperProfessor RibeiroAbstract: Aero elastic Wing will soon take the placeof today's wing control. These changes ought togenerate savings in weight and increases inreliability, employing technologies that have been indevelopment and testing for years. The research anddevelopment required for developing MAVs andrelated systems is technically challenging andrequires a number of technological advances thatmay benefit a broad range of aerospaceapplications. The development of a vehicle withaero elastic wing could also promote developmentof component technologies and help to support anemerging growth market for micro aerial vehicles. 1.0 IntroductionThe Air Force calls it “back to the future”—taking anelement of the Wright brothers’ original aircraft, afeature deliberately engineered out of modern planes,and putting it back, literally. In this case, it meansrestoring preproduction wings on a Navy F/A-18—wings that had been replaced because they twisted inflight. The active aeroelastic wing (AAW) aircraft is aunique joint research effort involving the Navy, the AirForce Research Lab at Wright-Patterson AFB, NASA-Dryden, and the Boeing Phantom Works. Funding forthe Navy plane comes from AFRL’s Air VehiclesDirectorate and NASA’s Office of AerospaceTransportation Technology, with Boeing performingthe F/A-18 modifications under contract to the AirVehicles Directorate. For his historic first flight onDecember 17, 1903, Orville Wright used themovements of his hips in the airplane’s “saddle”—inwhich he lay prone—to twist or warp either the left orright wingtip. This provided flight control without theuse of ailerons or flaps. While such aeroelastic warpingis inherent in the wings of modern high-speed aircraft,engineers have done everything possible to counteractit, from physically stiffening the wings to incorporatingother control surfaces. The degree of twisting involved is actually rather small—less than 4°. AAW technology you can provide a weight-competitive wing, reduce drag, improve range, and reducefuel consumption, because you have a moreaerodynamically efficient wing with an increased aspectratio1.Identify 3 axes of rotationAircraft fly in three dimensions, and they move indirections other than straight and level. The axis thatextends lengthwise (nose through tail) is called thelongitudinal axis, and rotation about this axis is calledroll. The axis that extends crosswise (wingtip throughwingtip) is called the lateral axis, and rotation about thisaxis is called pitch. The axis that passes verticallythrough the center of gravity (when the aircraft is inlevel night) is called the vertical axis, and rotation aboutthis axis is called yaw.Figure 1Role of Aircraft wings in different ManeuversBasic flight maneuvers include climbs, descents, turns,and combinations of these. Generally, the basic flightmaneuvers are started from what is called straight andlevel flight. Straight and level flight (also calledcontrolled flight) is a flight condition where the wingsare kept level and the altitude and heading constant.Power setting is maintained at 55 percent to 75 percentof available power. If speed is desired a higher setting isrequired, however if fuel needs to be saved then a lowersetting is required. Straight and level flight is a series ofslight adjustments or corrections in pitch, yaw, and rollto keep the wings level and heading and altitudeconstant. Climbs are a combination of power and "upelevator." The amount of power used determineswhether the climb is steep or shallow. In order to use allavailable power, the climb angle must be as steep aspossible. This is called the best angle of climb, but it is ashort-term climb. A sustained climb at this angle canoverheat the engine. The third basic maneuver is theturn. Turns are gentle, medium, or steep; and they maybe made when climbing, descending, or while notgaining or losing altitude. Causing the airplane to turnrequires smooth coordination of aileron, rudder, andelevator controls; in other words, pressure on the controlwheel and the rudder pedal should be appliedsimultaneously. The moment a wing begins to rise in abanked turn, it experiences more drag because of thelowered aileron and its higher angle of attack. Asimultaneous application of rudder compensates for thisadditional drag by making the airplane also rotate aboutits vertical axis.Figure 2: Elements of a turn2.0 HistoryWhen Orville Wright first took to the air on Dec. 17,1903, he didn't have ailerons or flaps to control hisairplane. Instead, the Wright brothers had chosen to twistor "warp" the wingtips of their craft in order to control itsrolling or banking motion. Rather than using one of thecraft's two control sticks to make the wingtips twist, theyhad devised a "saddle" in which the pilot lay. Cablesconnected the saddle to the tips of both wings. By movinghis hips from side-to-side, the pilot warped the wingtipseither up or down, providing the necessary control for theWright Flyer to make turns. The test aircraft chosen forthe AAW research is a modified F/A-18A obtained fromthe U.S. Navy in 1999. Begun in 1996, the AAW flightresearch program has completed detailed design and thewing modifications required for the program have beencompleted. The test aircraft has been
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