Computational Framework for Analysis of Aircraft Computational Framework for Analysis of Aircraft Nonlinear Dynamics & Control Design Based on Nonlinear Dynamics & Control Design Based on Qualitative Methods Qualitative Methods Mikhail Goman, Andrew Khramtsovsky, De Montfort University, UK Eugene Kolesnikov, Bombardier Aerospace, Montreal, Canada • GARTEUR FM(AG17), Stockholm, FOI, 21-22 March 2006
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Goman, Khramtsovsky, Kolesnikov (2006) - Computational Framework for Analysis of Aircraft Nonlinear Dynamics & Control Design Based on Qualitative Methods
М.Г.Гоман. А.В.Храмцовский, Е.Н.Колесников "Методика численного анализа нелинейной динамики самолета и синтеза системы управления на основе качественных методов анализа", встреча участников проекта GARTEUR в Стокгольме, 21-22 марта 2006 года.
M.Goman, A.Khramtsovsky, E.Kolesnikov "Computational Framework for Analysis of Aircraft Nonlinear Dynamics & Control Design Based on Qualitative Methods", GARTEUR meeting in Stockholm 21-22 March 2006.
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Computational Framework for Analysis of Aircraft Computational Framework for Analysis of Aircraft Nonlinear Dynamics & Control Design Based on Nonlinear Dynamics & Control Design Based on
Qualitative MethodsQualitative Methods
Mikhail Goman, Andrew Khramtsovsky, De Montfort University, UKEugene Kolesnikov, Bombardier Aerospace, Montreal, Canada
• GARTEUR FM(AG17), Stockholm, FOI, 21-22 March 2006
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 2
ContentsContents
• A bit about flight dynamics
• Computational framework for qualitative analysis of nonlinear aircraft dynamics (methods & tools)
• Attainable equilibrium sets (AES) for ADMIRE airframe
• Closed-loop dynamics & regions of attraction (RA) for ADMIRE+NDI
• Manoeuvre limitation based on analysis of AES & RA
• Summary
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 3
Kinematics of VelocityKinematics of Velocity--Vector Roll Vector Roll ManoeuvreManoeuvre
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 4
Velocity-Vector Roll Manoeuvre Visualization
Fa
Fa
ww
VV
Fa
VV
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 5
Kinematics of Velocity Vector Roll Manoeuvre
“ …The velocity vector roll is defined as an angular rotation of an airplane about its instantaneous velocity vector, constrained to be performed at constant angle-of-attack, no sideslip, and constant velocity…”
Wayne C. Durham, Frederick H. Lutze, William Mason, December 1993
Available definitions of velocity vector roll Available definitions of velocity vector roll manoeuvremanoeuvre like:like:
are valid only at very high rates of rotation as the radius of hare valid only at very high rates of rotation as the radius of helical elical
trajectory is inversely proportional to angular ratetrajectory is inversely proportional to angular rate WW
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 6
Kinematics of Velocity Vector Roll Manoeuvre
“ …The velocity vector roll is defined as an angular rotation of an airplane about its instantaneous velocity vector, constrained to be performed at constant angle-of-attack, no sideslip, and constant velocity…”
Wayne C. Durham, Frederick H. Lutze, William Mason, December 1993
Available definitions of velocity vector roll Available definitions of velocity vector roll manoeuvremanoeuvre like:like:
are valid only at very high rates of rotation as the radius of hare valid only at very high rates of rotation as the radius of helical elical
trajectory is inversely proportional to angular ratetrajectory is inversely proportional to angular rate WW
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 7
Kinematics of Velocity Vector Roll ManoeuvreKinematics of Velocity Vector Roll Manoeuvre
XX
VV
aabb
ww
WW
YYZZ
);,( dxfx =&
);,( dxfx =&Trqpx ),,,,( ba=
TTVTVcrEE rightleft
),,,,,(yq
ddddddd =
Natural kinematic parameters for Velocity Vector Roll
((a,b,Wa,b,W))
VVr
rr )( ×=W
wwhere
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 8
Methods & Tools for Qualitative AnalysisMethods & Tools for Qualitative Analysis
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 9
Computational Framework for Qualitative AnalysisComputational Framework for Qualitative Analysis
, convex optimization (controllability regions for linear unstable systems with limited control inputs), …
Controllability local and global
Continuation & systematic search methods Monte Carlo method, phase portrait investigation (iterative & incremental method), …
Multiple-attractors (critical flight regimes)
Jacoby matrix (eigenvalues, eigenvectors), Lyapunov function methods, computing invariant manifolds (region attraction boundary), 2-dim slices of region of attraction (RA), …
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 21
Feed-forward transformation
NDIBS or FL based
+ Reference Modelfor HQ
Control Allocation
(Newton-Raphsonbased)
Aircraftactuators,airframe,sensors
Signal conditioning
CVcom Mc CVd
CV = [a, b, W]’ - control variables; CVcom = [a, b, W]’ - control inputs;
d = [DEL,DER,DR]’ - control effector commands
Mc – control moment demand
max
maxmin
dd
ddd&& £
££
NDI-based control laws
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 22
NDI blockNDI block--functional diagramsfunctional diagrams
J-1(-wxJw + M) M
a a* - k1a(s)(a-a*) - k2a(s)(a-a*)b = Aw + Aw + E = b* - k1b(s)(b-b*) - k2b(s)(b-b*)W W* - k1W(s)(W-W*)
desired dynamics, stability, robustness etc.
..
..
.. . .
..
..
.
..
Feedback linearization (FL) NDI
ab = A(a,b)w + E(a,b,V,n,q,f)W
.
.
w = J-1(-wxJw + M).
a a* - ka(s) (a-a*)b = Aw + E = b* - kb(s) (b-b*)W W*
.
.
w = w* - Kw(s)(w-w*). .
M
Backstepping (BS) NDI
J-1(-wxJw + M)
.
.
desired dynamics... 1st level
desired dynamics…. 2nd level
a*,b*,W*
a*,b*,W*
abW
reference model for handling qualities
, kWs + kW
wa,b2
s2 + 2xa,bwa,bs + wa,b2
com
Equations of motion
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 23
openopen--loop loop AESAES
Nose Pointing Manoeuvre
closedclosed--loop loop AESAES
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 24
openopen--loop AESloop AES
Velocity-Vector Roll Manoeuvre
closedclosed--loop AESloop AES
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 25
Departure at Velocity-Vector Roll Manoeuvre
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 26
Open-loop system
Regions of Attraction for NDI closedRegions of Attraction for NDI closed--loop system:loop system:critical external disturbancescritical external disturbances
NDI closed-loop system
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 27
Convergence and Departure DynamicsConvergence and Departure Dynamics
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 28
Effect of Rate SaturationEffect of Rate Saturation
sdeg/50£d& sdeg/500£d&
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 29
AES of open-loop system
Regions of Attraction at Regions of Attraction at VelocityVelocity--Vector Roll Vector Roll ManoeuvreManoeuvre
Critical BoundariesCritical Boundaries
AES of NDI closed-loop system
Regions of AttractionRegions of Attraction
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 30
Manoeuvre limitation based on analysis of AES & RAManoeuvre limitation based on analysis of AES & RAAllowable NDI control inputs acom,bcom,Wcom
DD
- allowable inputs
critical boundariescritical boundaries
DD –– safety margin selected safety margin selected based on a size of RAbased on a size of RA
Next step Next step -- avoid rate saturation!avoid rate saturation!How?How?Why?Why?
GARTEUR FM(AG17) FOI, Stockholm 21-22 March 2006 31
Summary
• Computational framework based on numerical implementation of qualitative methods is feasible and effective approach to flightdynamics applications.
• Matlab tools for computation of AES for velocity-vector roll manoeuvre and regions of attraction RA for the closed-loop system allow the effective analysis of aircraft dynamics and manoeuvrability.
• Assignment of allowable NDI control inputs can be made using analysis of ASE and RA.
• The plan for future work: a) avoiding rate saturation in NDI control (?); b) control allocation and inversion at the presence of saturated control; c) …
• “… Noah’s Ark was built by amateurs and Titanic by professionals…”