The Skeldar V-150 flight control system. Modeling, identification and control of an unmanned helicopter. Saab AB. Saab Aerosystems.

Transcription

1 The Skeldar V-5 flight ontrol ytem Modeling, identifiation and ontrol of an unmanned heliopter Ola Härkegård LiTH, November 8, 27 Organization Saab AB Saab Aeroytem Aeronauti Flight Control Sytem Aerodynami & Flight Mehani F G 2

2 Airraft JAS 39 Gripen Shar Filur Skeldar V-5 3 Skeldar V-5 Unmanned heliopter for urveillane Under development Baed on APID-55 by CybAero 3.3 m 5 kg 4 2

3 Level of ontrol UAV pilot. Break point lit 2. High level ommand Heading, peed, altitude Adjut poition Guidane Path generation Flight Control Sytem Control 5 Deign loop Deired dynami Wind enitivity Heliopter dynami Atuator Senor Requirement Model Flight Deign parameter Deign method Controller Evaluation Analyi Simulation 6 3

4 Atuator 3 main rotor ervo: pith (yli pith) roll (yli roll) vertial (olletive pith) Throttle ervo: RPM Tail rotor ervo: yaw 7 Senor AHRS-GPS Rate gyro Aelerometer Magnetometer GPS Senor fuion Angular veloity Orientation Veloity (relative ground) Poition Radar altimeter Air-data ytem 8 4

5 Dynami 9 Modeling Air flow Aerodynami & flight mehani. Phyial modeling Linkage Engine 2. Sytem identifiation Flight data Σ: 26 th order nonlinear ro-oupled ytem Blak box model Model truture 5

6 Rotor dynami Flapping equation β + β + + d β = ψ Parametrization β = β + β inψ + β ( ) ( ) oψ Tip-path-plane (TPP) dynami: Ω blade pith angle body rotation 2π-periodi β + β β + β + dβ β + β + dβ + ( + d) 2β β + 2β + β β = u = u = u β Redued TPP-dynami β + β + ( + d) β = u β + β + dβ 2β β = u β + β + dβ + 2β + β = u β = u β = β τ β = β τ + u 2 u 2 Firt order dynami from input to rotor di orientation 2 6

7 Body dynami Pith moment F M ( k + hf) β Ditane to.g. M Spring ontant Pith dynami β M q& = J 3 Coupled rotor body dynami Mehanial feedbak Inreae tability Swah plate Stabilizer dynami Blade dynami Body dynami Pith rate Ue Ue enor enor feedbak intead? Mikado virtual flybar 4 7

8 Sytem id pith dynami. Etimation q dpith Time 2 nd order ytem G 2. Validation q.4 dpith 4 Real data Model.2 G Time Time 5 Open loop pith dynami Kinemati u G rotor q θ g v x Moment equation Fore equation 6 8

9 Control deign Nonlinear ontrol MIMO ontrol Contrained ontrol Referene feedforward Adaptive ontrol Linear SISO feedbak 7 Control law Referene following Feedforward turn oordination limb yaw k r k f r k i y Remove tationary error K Artifiial damping In pith: q, θ v x, x 8 9

10 Feedbak Open loop dynami u G rotor q θ g v x LQ deign. Hover 2. Flight: u = k q k θθ k v k x k x q u = k q kθθ k v k v q v v x x i Are LQ robutne propertie retained? 9 Feedforward DOF ontroller Contain integral ontrol G r e F H y Nie truture BUT... lim e = lim E = lim t + FG = lim FG = Overhoot No good! 2

11 Solution: Set-point weighting Modified PI-ontroller ( r y) + k ( r ) u = kp β i y Set-point weight β Example: G =, kp =.3, ki =. 3 loed loop pole: -.94, Step Repone Pole-Zero Map.2 β =.5 Amplitude β =.74 β = Imaginary Axi Time (e) Real Axi 2 Conluion Many ontrol tool ueful if you know them identifiation, LQ, phae diagram, Nyquit theorem, model redution, feedforward, anti-windup, bumple tranfer,... Dynami intuition valuable Saab need more ontrol dotor F G 22

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