MAV activities in flight dynamics and control
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Prof A.V. Efremov, Ph. D., D. of Sc.,The Head of Flight Dynamics and Control Department,
Moscow Aviation Institute
97 SAE Aerospace Control and Guidance Systems Committee Meeting
Lake Tahoe, NevadaMarch, 2006
1. Flying qualities evaluation in different piloting tasks.
2. Manual control for ESTOL.
3. Micro aerial vehicle dynamics, flight control and design.
4. Pilot behavior modeling.
RESEARCHES 2005
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• Improvement of agreement between in-flight and ground based simulations;
• Development of data base on ground based evaluation of Flying Qualities for the further researches in manual control area;
• Development of technique for ground based simulation accompanying in-flight evaluation of Flying Qualities;
• Determination of the factors defined pilot rating.
FLYING QUALITIES EVALUATION
Goals of investigations
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• Landing;
• ESTOL;
• Aim-to-aim tracking;
• Formation flight;
• Refueling.
INVESTIGATED PILOTING TASKS
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• selection of dynamic configurations;
• definition of task performances (desired, adequate) and additional variables (conditions for stress situations, number of attempts in each experiment, etc);
• generation of input signal;
• development of questionnaire for each piloting task;
• data reduction.
The stages for flying qualities investigationsin each piloting task
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Table of all experimental researches
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Piloting task Configurations Number of experiments Comment
Landing31 (including HAVE PIO, LAHOS and others)
1185171 experiments with side stick. 3 landings in each experiment.
Refueling29 (including HAVE GAS, Neal-Smith and others)
263 3 – 11 attempts in each experiment.
Aim-to-aim tracking 11 (Neal-Smith) 68
Formation flight 31 66
Aim-to-aim tracking tasks (on workstation) 42 534 84 experiments with
the motion cues.
ESTOL 5 91Configurations differ by level of augmentation
Total: 2060(> 6200 runs)
At least 3 runs in each experiment
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DEFINITION OF TASK PERFORMANCES
Refuelingpercentage of successfulattempt (desired, adequate)
Landing (desired, adequate)
hAir-to-air trackingaccuracy (desired, adequate)
mrad ,
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GENERATION OF INPUT SIGNAL
Math model of drogue motion Data reduction
development of spectrum and its approximation
ΔХ
ΔZ Video tape
recording of the real drogue
motion
tAlk
lklk,
,, sin
Refueling
9REFUELING
AIR-TO-AIR TRACKING10
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QUESTIONNAIRE (pilot comment card)
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Correlation of pilot rating PR with max PR of FQ in longitudinal ( ) and lateral ( ) channels.PR PR
) ,max( PRPRPR
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AGREEMENT BETWEEN GROUND-BASEDAND IN FLIGHT SIMULATION
Landing
Initial stage (2001)
ΔPRflight
ΔP
Rgr
oun
d
ΔPRflight = 8 ΔPRground = 4,5
Final stage (2005)
ΔPRflight = 8 ΔPRground = 6,5
14AGREEMENT BETWEEN GROUND-BASED
AND IN FLIGHT SIMULATION IN DIFFERENT PILOTING TASKS
— in flight
— ground-based
6.5
8.0
9.0 9.0
5.05.5
Δ PR
Landing Refueling Aim-to-aim tracking
2.0
4.0
6.0
8.0
10.0
0
Lev
el o
f ra
tin
g
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Manual control for ESTOL
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PROBLEMS
Low velocity in manual landing
High Thrust Force and angle of attack
Possible loss of visual contact with ground
surface
Unsatisfactorylateral FQ
ReversibleControl
in longitudinal channel
Solution of problems
TV camera for visual contact with ground
surface + display with additional metrics and
Zoom = f(L)
Bank anglefeedback control
Velocityfeedback control
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EFFECT OF FLYING QUALITIES IMPROVEMENT :
а) improvement of pilot rating :
without automation PR = 8,
with developed means PR = 4 – 5
б) improvement of accuracy (variance of longitudinal error) in 15 times
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MAV dynamics and design
Peculiarities of MAV
• Low velocities, mass, inertia, wing loading.
Aircraft MAV
mg/S, n/m2
inertia Iy , kg/m4
200 400 ~ 2
104 105 0,5 ·10-3
• Low Reynolds numbers peculiarities in aerodynamics.
• unusual dynamic response:
– instantaneous change of moments and quick change of forces
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First phase of investigation(april – september 2004)
– Estimation of aerodynamic coefficients (CL , CD , mq , mδ … ).
– Estimation of flight performances and flying qualities.
– Simulation of flight.
– Preliminary FCS design.
M
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Analysis of MAV flight dynamics
s1s
2 ss2 ωsp
2ωspξsp
s2sz
)( sδe
)( sΘ
Phugoid mode Short-period mode
ωph
ωsp
s1
s2
Aircraft MAV
0,1-0,01 0,8-1,5
1-3 15-20
1-2 10-20
0,01-0,001 0,1-0,5
MAVaircraft
2 ss2 ωph
2ωphξph
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Ways for improvement of MAV flying qualities
Radiocanal
RadiocanalOperator
station Prefilter MAV TVcamera
Use of prefilters
WФ = WФ1 WФ2
WФ1 = T1 s + 1
T1 s
T1 = 0,5c
WФ2 = T2 s + 1
1
T2 = 0,2c
TV-signalControlsignals
RECIEVER Operatorstation
TRANSMITTER– COMPUTER
– AD / DC (converter)
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1. Wind tunnel tests
2. Modification of mathematical model
3. Automation of MAV
4. MAV design
Second phase of investigation(2005)
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WIND TUNNEL TESTS
GOALS
• Influence of low Reynolds numbers, Re
• Influence of propeller
а) Considerable increase of СL max
b) Decrease of L/D ratio
)(vFDL
24Models in the Wind tunnel
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1. Longitudinal channel
Automation of MAV
t, c
q δe
H δe
2. Lateral channel
p δr
ψ δr
r δa
φ δa
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FIRST FLIGHT OF DEVELOPED MAV
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