介绍飞行控制系统的国外研究现状课件.ppt

Flight Control Law Design:An Industry PerspectiveGary J.BalasAerospace Engineering and MechanicsUniversity of MinnesotaMinneapolis,MN 55105 USASeptember 4,20032003 European Control Conference1ECC2003Presentation OverviewSurvey of the control techniques being used by industry in Brazil,Europe,Russia and the United States of America to design flight control laws for fixed-wing aircraft.2ECC2003Outline100 years of Controlled FlightIntroductionBackgroundCountriesBrazilEuropeFranceGermanyItalySwedenUnited KingdomIsraelRussiaUnited States of AmericaBoeingHoneywellLockheed MartinSummary3ECC2003Wright Brothers:December 17,1903First to develop a fully aerodynamic control system coupled to a powered aeroplane which was both flyable and maneuverable.4ECC2003Cambridge University,EnglandLord Kelvin,President,Royal Society,undergraduate at Cambridge University,Senior Wrangler6ECC2003Cambridge University,EnglandLord Kelvin,President,Royal Society,undergraduate at Cambridge University,Senior Wrangler“Heavier-than-air flying machines are impossible”(1895)I have not the smallest molecule of faith in aerial navigation other than ballooning.I would not care to be a member of the Aeronautical Society,(1896)7ECC2003Current/New Commercial AircraftBoeing 7E7 DreamlinerAirbus A380Embraer ERJ-170Dassault Falcon 2000EX8ECC2003Current/New Military AircraftEurofighter TyphoonSukhoi SU-37Chengdu J-10Indian Light Combat AircraftMIG 1.44F/A-18 E/FSukhoi-30MKK10ECC2003Uninhabited Aerial Vehicles(UAVs)PredatorGlobal hawkOrganic Air VehicleDragon EyeNeptuneRavenFPASS11ECC2003Uninhabited Aerial Vehicles(UAVs)US Department of Defense(DoD)has 20 UAVs in service or under conceptual development:DoD will have invested over$10 Billion in UAVs by 2007*.DoD UAV systems will grow to 300 by the year 2010*.32 Nations are developing more than 250 models of UAVs*.Over 60 small and Micro UAV programs are under way through out the world.*DoD Unmanned Aerial Vehicle Roadmap:2002-202713ECC2003BackgroundSurvey of the current practices and control design approaches used by the aircraft industry.Brazil,Europe(France,Germany,Italy,Sweden,United Kingdom),Israel,Russia,United States of AmericaCaveats:Limited information on techniques used in industry.Some companies consider the control architecture,algorithms etc.to be IP.Companies that publish more are better represented in this talk.Almost all the references cited were published in English.15ECC2003BrazilEmbraer ERJ-170 aircraftFlight control design philosophyDocile and benign as possible flying qualities behavior(behaviour)Digital fly-by-wire(FBW)control system would allow complex flight controllers,cost constraints and accelerated time schedule led to selection of standard classical flight control system.In-flight simulation using Veridian Variable Stability Learjet.16ECC2003EuropeLong tradition of aeronautical research.Close links between universities and industryTo increase cooperation,the Association of European Research Establishments in Aeronautics(EREA)found in 1994.CIRA(Italy),DERA(Great Britain),DLR(Germany),FFA(Sweden),INTA(Spain),NLR(Dutch)and ONERA(France,1999).Group for Aeronautical Research and Technology in Europe(GARTEUR)GARTEUR Flight Mechanics Action Group 08(1994-1997)Robust control design methodsGARTEUR Flight Mechanics Action Group 11(1999-2002)New Analysis Techniques for Clearance of Flight Control LawsMany European aircraft industries are multi-national and parts of the same aircraft flight control laws are designed in more than one country.18ECC2003FranceConcordeEpsilonRafale19ECC2003FranceMirage 2000,Rafale CAirbusMajor partner in European consortium of French,German,Spain and U.K.companiesA300/A310,A320,A330/A340,A380 under design.Developer of commercial fly-by-wire(FBW)system.A320 was first commercial aircraft to enter service with a FBW flight control system(1988).A340 2nd generation FBW certified in 1992.All Airbus flight control surfaces are electronically controlled and hydraulically activated.UAVs20ECC2003France Airbus A320A320 Flight Control LawsImprove the natural flying qualities,particularly the stability,control and flight envelope protection.Longitudinal ControlLoad factor demandsClassical proportional plus integral controlLateral-directional ControlRoll rate,sideslip and bank angle commandsClassical proportional plus integral control with a gain matrix for stability and roll rate/sideslip decoupling.21ECC2003France Airbus A340A340 Flight Control LawsReproduced architecture/principles for A320Increased size and flexibility,required addition of structural mode control to reduce structural mode vibration.Structural Mode Suppression Controller Manual flight controller/Autopilot modified to eliminate interaction.Turbulence damping function added to attenuate fuselage response.Sufficient bandwidth separation between two controllers minimized interaction.Accelerometers were added to sense vibration.22ECC2003France Airbus A380Airbus A380 ApproachAirframe flexibility taken directly into account when designing the flight control laws.Integrated flight control laws to achieve desired handling qualities and flexible mode damping requirements leading to extended control bandwidth.Flight tested on A340 using A380 modelsRobust to fuel,payload,etc.variationsSame concept applied to autopilot and manual control laws.24ECC2003GermanyCommercial AviationAirbusDLR experimental aircraft(ATTAS)Advanced Technologies Testing Aircraft System.Military AviationEurofighterX-31(US/Germany program)25ECC2003GermanyX-31A Post stall experimental aircraft(US/Germany program)First X program with Intl partnerEnhanced Fighter ManeuverabilityEFM using thrust vectoringGoal:tactical advantage of EFM in post stall up to 70 deg AoARockwell and MBBX-31A Flight Control LawsPilot cmd(p,q,r)Sensed feedback(p,q,r,)Actuation cmd(SF,DF,C,R,)K-LTI controllerOptimal LQ digital regulatorScheduled with,M,hNonlinear feedforward blocks26ECC2003GermanyFlight control system for A380Size and flexibilityEU funded REAL(Robust and Efficient Autoland control Law design).Industry and research institutions from France,Germany and the NetherlandsBenchmark was DLR ATTAS aircraft.DLR REAL flight control design approachMulti-Objective Parameter Synthesis(MOPS).Robustness addressed via multi-model,optimization,Monte-Carlo analysis.28ECC2003Germany-REALStability/command augmentation,tracking,guidanceInner loops designed using dynamic inversion.Total Energy Control System(TECS)Lateral tracking uses classical PI control with tuning parametersTuning based on multi-criteria/multi-model parameter opt using MOPS.29ECC2003Germany-IRIS-TInfra-Red Imagining System-Tail(IRIS-T)Missile Thrust-vectored control,next generation short-range missile.Being developed with Greece,Italy,Norway and Sweden.Extreme maneuverability.-synthesis robust control technique used to design lateral and roll controllers.Scheduled on dynamic pressureSuccessful flight test in May 2000.31ECC2003ItalyEurofighterGermany,United Kingdom,Italy,Spain.Quad redudant,full authority DFCS.Alenia responsible for basic autopilotLongitudinal axis controls attitude or pitch angle,lateral axis controls bank angle and heading.Autopilot designed using classical control tools.Control structure defined,Nicholas/Bode plots,linear time responses.Large amplitude,nonlinear closed-loop simulations.Modified control structure with nonlinear elements.Mode logic increased nonlinear elements to satisfy mode schedules.32ECC2003SwedenSaab/BAE JAS 39 GripenContract awarded in 1982Lightweight,multi-role combat aircraftAll moving,delta canard configurationHungary(2003)orders 14,232 orderedSAABSHARC33ECC2003SwedenPilot-induced Oscillation(PIO)First test aircraft crashed after 6th flight(1989),first operational aircraft crashed in 1993.Partial cause:PIO related to control surface servo rate limits.Reduced phase margin or extra delay in feedback loop.34ECC2003SwedenController modification based on PIOsFeedback phase compensation based on anti-windup methods.Increased or advanced phase around nonlinearity.Low pass filters used to eliminate biases and high frequency roll off issuesFlight tested and verified.Phase compensation technique used in place of rate limiters in Gripen production flight control system.35ECC2003United KingdomCommercialAirbusMilitaryHarrierSaab/BAE JAS 39 GripenEurofighterLockheed Martin/BAE F-35 JSF36ECC2003UK-Jaguar and EAP ProgramsFBW Jaguar program(1980s)precursor to VAAC Prove principles of active control technology,establish design and flight clearance techniques for DFCS.First UK aeroplane equipped with full authority DFCS.37ECC2003UK-Jaguar and EAP ProgramsExperimental Aircraft Programme(EAP,1983-1995)Follow on from Jaguar programme.Control design process:Linear low frequency:PI scheduled as function controlNonlinear:trim distribution,nonlinear control power,nonlinear variations of stabilityLinear high frequency:avoid structural couplingLessons learned:separate regulator and command path designs.FBW Jaguar and EAP shaped Eurofighter flight controller38ECC2003United KingdomVectored thrust Aircraft Advanced Control(VAAC)programInception in 1984.Handling,control and display requirements for future short takeoff/vertical landing(STOVL)aircraft.Experimental FBW VAAC Harrier.Development and testing of advanced aircraft flight control algorithms.Longitudinal axis,integrated management of thrust vectoring and aerodynamic forces for decoupled control.39ECC2003UK-VAAC Control StrategiesClassical control,loop-at-a-timeFrequency shaping,gain-scheduling,significant nonlinearities linearized with inverse functions,iterative design.Anti-windup scheme and control allocation.Nonlinear static inverseNonlinear inverse of the aircraft to determine control effectors to trim.aircraft at a given maneuvering state.Constrainted design process used to define unique solution to non-linear inverse problem(trim map).Nonlinear inverse feed-forward combined with low gain,classical feedback design for stability.40ECC2003UK-VAAC Control StrategiesNonlinear Dynamic Inversion(NDI)Nonlinear dynamic model of aircraft used to invert nonlinearities and a classical PI controller designed to track desired pitch rate command.Pilot commands filtered prior to input to NDI controller.41ECC2003UK-VAAC Control StrategiesH loop shapingMultivariable linear controllers at 4 points:hover-to-forward flight.Inner-loop pitch rate feedback used to reduce effect of pitch moment due to thrust changes.Outer-loop 3-input/3-output,H loop shaping to control normal and forward acceleration and incidence.Weight selection similar to classical loop-shaping.Four linear point designs gain-scheduled throughout flight envelope.Controller implemented in observer form.Interpolated controller gains and interpolated controller outputs.H loop shaping techniques also used to synthesize an integrated longitudinal/lateral flight and propulsions control system for VAAC.42ECC2003UK-VAAC Control StrategiesLinear,parameter-varying(LPV)controllerSystem dynamics written as LTI models whose state-space coefficients are a function of scheduling variable(s).LPV H loop shaping uses LPV model of nonlinear aircraft dynamics to directly synthesize a scheduled LPV controller.Successfully implemented at tested between 1995 and 1998.43ECC2003IsraelLight,multi-mission fighter“Lavi”Initial flight test:31 Dec 86,program terminated:30 Aug 87Flight control lawsClassical technique with optimal control methods used in preliminary design process.Lessons learned:Relationship between control design parameters and flying qualities.UAVs44ECC2003RussiaSU-27SU-30MKSU-35 SuperFlanker45ECC2003RussiaMIG-29SU-37 TerminatorTU-22SU-2746ECC2003RussiaSU-30MKTU-160SU-3747ECC2003RussiaExtensive history of military/commercial aircraft development.English language literature on Russian industry flight control design techniques is limited.Sukhoi 37 FBW flight controllerQuad redundant DFCSDesign requirementsGood handling qualities.Optimal trimming.Reconfigurable under flight control system failures to maximize control moments and trim configuration.Adaptive controller designed to eliminate small amplitude self-induced oscillations due to actuator nonlinearities.48ECC2003Russia-SU-37 AircraftCanards and thrust vectoring(TV loop not shown.).Longitudinal controller synthesized with classical control methods.49ECC2003United States of America(USA)CommericalBoeing(McDonnell Douglas)B-717,B-737,B-747,B-757,B-767,B-777HoneywellMilitaryLockheed Martin(General Dynamics)F-16,F-22,F-35(JSF)Northrup GrumannF-14,F-20,B-2Boeing(McDonnell Douglas,North American Rockwell)B-52,B-1B,C-17 C-40A,F/A-18,KC-10Honeywell50ECC2003USAAV-8 HarrierB-2 SpiritB-747B-747C-5 Starlifter51ECC2003USAB-747UCAVF-117AU-2F/A-18E/F52ECC2003USA-1947B-747B-377 Stratocruiser53ECC2003USA Flight Control SpecificationsMultivariable ControlMultiple sensors,disturbances,objectives,surfaces(TV)with coupling.Military specifications focus on SISO,loop-at-a-time analysisMultivariable Control Design Guidelines(1996)Honeywell Research Labs,Lockheed Ft.Worth,Lockheed Skunk Works Eigenstructure assignment,dynamic inversion,-synthesisF-177,YF-22 and MCT/F-16Report provides a reference point for the US Air Force to evaluate the design of future flight control systems.54ECC2003BoeingThe Boeing CompanyLargest manufacturer of aircraft in the world.Merger of Boeing,Rockwell International and McDonnell DouglasVariety of approaches to flight control designMultivariable Flight ControlFirst application in 1978 as part of a NASA research program.Since 1980s,multivariable control as been applied to a number of aircraftMultivariable control with classical frequency-domain interpretations.Guidelines to transform design requirements into mathTraining of control engineersUser-friendly control software programs.55ECC2003BoeingMultivariable Control DesignLQR/LQG basedPerformance and robustnessDirect tradeoff between command response,control activity,disturbance rejection and loop bandwidthKey:Selection of variables to regulate and controls to perform regulation“Integral”regulators augmented,zero steady-state errors to constant inputs56ECC2003BoeingIntegral LQR/LQG design procedure:Select controls and regulated outputs:#controls=#regulated variables.Check singular values and transmission zeros.Attach integrators and set target zeros.Select Q and R matrices for LQR problem.Q and R selected based on command loop crossover frequencies.Q(R)diagonal,qi(ri)adjusts bandwidth of command loop for yi(ui).Check loop at input to integrator and actuator.Note that the control loop crossover frequency is limited by the actuator capabilities and structural mode coupling.Verify that the phase margins at higher frequencies are sufficient.Feed-forward gains adjusted for flying qualities.57ECC2003BoeingApplied to B-767,JSF(Boeing),UCAV,JDAM MMT and ACTIVE F-15.58ECC2003Boeing X-36B-747X-36 Prototype fighter aircraftStealth and agility prior to UCAV28%scale,remotely pilotedReconfigurable flight control lawsR