Ku LX-E 28.10.04 Slide 1 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Die Flugsteuerung des Hubschraubersvon den Grundlagen bis zur Einzelblattsteuerung
Dr. Oliver KunzeProduktentwicklung LX-EZF Luftfahrttechnik GmbH
Praxis-Seminar LuftfahrtFachhochschule Hamburg
Hamburg, d. 28.10.2004
Die Die FlugsteuerungFlugsteuerung des des HubschraubersHubschraubersvon den von den GrundlagenGrundlagen bisbis zurzur EinzelblattsteuerungEinzelblattsteuerung
Dr. Oliver Dr. Oliver KunzeKunzeProduktentwicklungProduktentwicklung LXLX--EEZF Luftfahrttechnik GmbHZF Luftfahrttechnik GmbH
PraxisPraxis--Seminar Seminar LuftfahrtLuftfahrtFachhochschuleFachhochschule HamburgHamburg
Hamburg, d. 28.10.2004Hamburg, d. 28.10.2004
Ku LX-E 28.10.04 Slide 2 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 3 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 4 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Comparison of 1930 Aircraft Maturity, Helicopter vs. Fixed Wing
Do X giant seaplane:MTOW: 48to Distance: 2800km Endurance: 14h
Helicopter by C. d’Ascanio:Altitude: 18m Distance: 1078m Endurance: 8:45min
Ku LX-E 28.10.04 Slide 5 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Standard Configuration
Ku LX-E 28.10.04 Slide 6 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Lockheed AH-56A Cheyenne Compound Aircraft
Ku LX-E 28.10.04 Slide 7 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Tiltrotor Aircraft Bell/Boeing V-22 Osprey
Ku LX-E 28.10.04 Slide 8 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Relative Power Required vs. Forward Speed
0
100
200
300
400
0 50 100 150 200
V [m/s]
P/m
[kW
/to]
Helicopter Compound
AirplaneTilt-Rotor
Ku LX-E 28.10.04 Slide 9 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Velocity Distribution over Rotor Disk (Advanced Ratio µ = ΩR / V)
Ku LX-E 28.10.04 Slide 10 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 11 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Rotor Blade Lift and Flap
Ku LX-E 28.10.04 Slide 12 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Blade Control System Using a Conventional Swashplate Arrangement
+ϑ
-ϑ
Ku LX-E 28.10.04 Slide 13 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Angle-of-Attack Distribution in Forward Flight
Level Flight
Ku LX-E 28.10.04 Slide 14 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Main Rotor Control SystemEurocopter (MBB) BO105
Primär-steuer,stehend
Taumel-scheibe
Pitch Horn
Steuer-stange
Ku LX-E 28.10.04 Slide 15 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Conventional Mechanical Primary Control System
Ku LX-E 28.10.04 Slide 16 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Main Rotor Sikorsky CH-53G
Ku LX-E 28.10.04 Slide 17 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Main Rotor Sikorsky CH-53G
Primär-steuerBooster
Pitch Horn Steuerstange (hier IBC-Aktuator)
Taumelscheibestehende Schere
Ku LX-E 28.10.04 Slide 18 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Main Rotor Control with SpiderWestland Sea Lynx MK88
Hub
PitchControlRod
SpiderArm
Spindle
Gimbal Joint
RollerBearings
Ku LX-E 28.10.04 Slide 19 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
NHI NH-90
Erstflug: 18. Dezember 1995Quadruplex fly-by-wire Steuerung
Ku LX-E 28.10.04 Slide 20 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Main Rotor Design – 1950/60s
AEROSPATIALE AS 341 Sikorsky S-58
Ku LX-E 28.10.04 Slide 21 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Main Rotor Design – Bell 412
Damper andFeather BearingLag Hinge
Virtual FlapHinge
Ku LX-E 28.10.04 Slide 22 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 23 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Limiting Phenomena Encountered bya Helicopter Rotor in Forward Flight
Mach Number Effects
Yawed Flow
Reversed Flow
Rotor Wake Interferences
Dynamic Stall Due to Blade Vortex Interaction
High Angles of Attack
Ku LX-E 28.10.04 Slide 24 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Vibrations:Source ⇒ Flexible Structure ⇒ Reaction
Periodic and Impulsive Blade Loads
Flexible Rotor/Body Load Paths
Rigid Body MotionsStructural Modes
Flexible BladeCoupledEigenmodes
Ku LX-E 28.10.04 Slide 25 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Vibration Levels of 6 Different Helicopter Types (BO-105 4- and 5-Bladed, CH-53G Aluminium and IRB Blades, Tiger, UH-60)
0.0
0.1
0.2
0.3
0.4
0.5
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45Advance Ratio
n Bl/r
evVi
brat
ion
at P
ilot S
eat [
g]
NASA Recommen-dation
MIL-H-8501A (1962)
Ku LX-E 28.10.04 Slide 26 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Passive Vibration Absorber and Isolation Systems
Cabin AbsorberPendulum Absorber
Nodal BeamIsolation System
FlappingMass
FlexibleLeaf
CabinStructure
Bifilar Absorber
AntiresonanceIsolation System
Ku LX-E 28.10.04 Slide 27 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
BVI-Noise Generating Mechanism
Air Flow
Modified Vortex Strength
Reduced Pitch during BVI
ψ = 90°
ψ = 0°
Ku LX-E 28.10.04 Slide 28 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Example of Helicopter Rotor Sound Spectrum (l.h.s.) and Average Time History (r.h.s.)
Ku LX-E 28.10.04 Slide 29 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 30 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Individual Blade Control through Blade Rootor Trailing Edge Flap Actuation
Blade RootActuator Electrically
Driven TrailingEdge (Servo) Flap
Ku LX-E 28.10.04 Slide 31 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Individual Blade Control through BladeTwist or Trailing Edge Flap Actuation
Ku LX-E 28.10.04 Slide 32 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
IBC Blade Pitch Control with higherharmonic blade pitch movements
0
2
4
6
8
10
12
0 45 90 135 180 225 270 315 360
Rotor Head Azimuth Angle [°]
Bla
de P
itch
[°]
with IBC
primary control
IBC Blade PitchMovementcharacterization:
• frequency (2 .. 7 ΩRotor)
•amplitude (0..3..6°)
• phase (0..360°)
Ku LX-E 28.10.04 Slide 33 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Modification of Local Angle of Attack through IBC
Rotor Azimut Angle ψ [Deg.]
Res
ulta
nt A
ngle
of A
ttack
αre
sat
B
lade
Rad
ial S
tatio
n r/R
= 0
.7
[Deg
.]
with IBC
Baseline
0 90 180 270 360
y
x
r
ψΩ
15
10
5
0
-
-
+
+
++
Ku LX-E 28.10.04 Slide 34 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Principle Layout of IBC System
BLADE-ROOT IBCPITCH ACTUATORS
HYDRAULICPOWER PICK-UP
HYDRAULICMANIFOLD,
MONITORINGAND SHUT-OFF
A
B
ELEC. & HYDRAUL.ROTARY TRANSMISSION
CONVENTIONALFLIGHT CONTROL
SYSTEM
DIGITALCOMPUTER
HYDRAULICDISTRIBUTION
FEEDBACKSIGNALS
CONTROLPANEL
IBC POSITIONCOMMANDS
Ku LX-E 28.10.04 Slide 35 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
IBC Actuator Mounted between Swashplate and Blade Pitch Horn Replacing the Rigid Pitch Rod
Ku LX-E 28.10.04 Slide 36 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Full Scale UH-60 Rotor Wind TunnelTests conducted at NASA Ames
Ku LX-E 28.10.04 Slide 37 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
IBC Inputs and Test Conditions
Ku LX-E 28.10.04 Slide 38 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Large Wind Tunnel at NASA Ames Research Center
Ku LX-E 28.10.04 Slide 39 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Testbed BO-105 S1 with IBC System
Ku LX-E 28.10.04 Slide 40 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
IBC Testbed CH-53G 84+02 Operated by WTD 61
Ku LX-E 28.10.04 Slide 41 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Dynamic Components with IBC Mock-Up
Ku LX-E 28.10.04 Slide 42 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
IBC Data Processing and Control Computer (ZFL) and Data Gathering System (WTD 61)
Ku LX-E 28.10.04 Slide 43 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Effect of 0.15deg 5/rev IBC on 6/rev Accelerations at Main Gear Box and Pilot Seat @120kts
x y z
x y z
Pilot Seat
MGB
Ku LX-E 28.10.04 Slide 44 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Effect of 0.15deg 5/rev IBC on z-Vibration Spectrumat Pilot Seat @120kts
without IBC
with IBC
Ku LX-E 28.10.04 Slide 45 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
C.L. Test Sequence @70kts, Single Mode 5/rev IBC Controlled Variable: 6/rev AccPilz
CL
OLPhaseSweep
90%
refrefref
ref
Ku LX-E 28.10.04 Slide 46 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Predicted Multi Harmonic Vibration Reduction at Main Gear Box Based on Single Harmonic Flight Test Data (0.15deg IBC at 90kts)
G(AccHGx,AccHGy,AccHGz)
100
Vib
ratio
n R
educ
tion
[%]
Numerically Predicted 6/rev Vibration Reduction at Main Gear Box (All Three Axes) Due to Different IBC Frequency Combinations
80
60
40
20
06/rev 4, 6/rev 4, 6, 7/rev 4, 5, 6, 7/rev
0.35
Req
uire
dA
mpl
itude
s[d
eg]
0.30
Corresponding Amplitudes Required0.25
0.20
0.15
0.10
0.05
0.006/rev 4, 6/rev 4, 6, 7/rev 4, 5, 6, 7/rev
Ku LX-E 28.10.04 Slide 47 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Noise Reduction Due to 2/rev 0.66deg IBC at Three Microphones (65kts, -6deg, Optimum IBC Phase)
1031009794918885
Mic #2 (Retr. Side)
1031009794918885
Mic #1 (Center)
VIAS = 65kts, γ = -6°N
on-c
orre
cted
Sou
nd P
ress
ure
Leve
l[dB
]
1031009794918885
Mic #3 (Adv. Side)
-10 -8 -6 -4 -2 0 2 4 6 8 10
Time [sec] (t=0 at moment of highest sound pressure level)
Reference, no IBCA2 = 0.67°, ϕ2 = 30°
Ku LX-E 28.10.04 Slide 48 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Flight Performance Relevant Parameters During 2/rev IBC Phase Sweep
4500
4000
3500Alti
tude
[ft]
#1 #2 #3 #4 #5 #6 #7 #8Data Points
16 Revs≈ 5 sec
135
130
125
120VIA
S [k
ts]
Level Flight VIAS = 125kts, A2 = 0.67°w/o IBC ϕ2 = 0° = 60° = 120° = 180° = 240° = 300° = 359°
2600
2500
2400
2300
Pow
erQ
·Ω[k
W]
Ku LX-E 28.10.04 Slide 49 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Effect of 2/rev 0.66deg IBC on Power Required (125kts, Net Effect, Corrected by Speed, Accel. and Heave Effects)
IBC Phase Angle
-15.00
-10.00
-5.00
0.00
5.00
10.00
15.00
0 60 120 180 240 300 360
ϕ 2 [°]
∆P
[%] (
corr
ecte
d)
More Power Required
Less Power Required
Ku LX-E 28.10.04 Slide 50 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Reduction of Pitch Link / Actuator Load by Application of Optimum Phase 2/rev IBC (A2 = 0.66° ϕ2 = 270°)
Ku LX-E 28.10.04 Slide 51 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 52 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Integration of IBC-System into CH-53G Testbed
Ku LX-E 28.10.04 Slide 53 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
ZFL´s IBC Actuator Evolution
TSS
BO 105 F/T
UH-60A WT/T
CH-53G F/T
BO 105 WT/T
Ku LX-E 28.10.04 Slide 54 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
CH-53G IBC Experimental System Actuator Design
Ku LX-E 28.10.04 Slide 55 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
IDS IBC DC test bench with reversedkinematics non rotating ↔ rotating
11 kW electrical drive
electrical slip ring
torque/speed sensor
hydraulic manifold
4 IBC actuators
IBC DC pump
pump control unitin drive cage
Ku LX-E 28.10.04 Slide 56 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Adaptation of Existing IDS to Lynx Rotor Hub
Ku LX-E 28.10.04 Slide 57 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
InHuS: Innovative Integrated Primary and Individual Blade Control System for Helicopters
IDS:Integration of BothPrimary Control andIBC intoGearbox/Rotorhub
IBC:Hydraulic and ElectricalIndividual Blade Control Systems withHigh Bandwidth butLow Authority
InHuS:Control System in theRotating Frame at Blade Root, Combining BothPrimary Control and IBC Using One Actuation System
Ku LX-E 28.10.04 Slide 58 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
InHuS: Innovative Integrated Primary and Individual Blade Control System for Helicopters (preliminary design)
Ku LX-E 28.10.04 Slide 59 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Helicopter Flight Control – from primary to individual blade control
OverviewOverviewHistory / Configuration and History / Configuration and Performance of a HelicopterPerformance of a HelicopterMain Rotor / Main Rotor Control Main Rotor / Main Rotor Control DesignDesignProblems of the Main Rotor Problems of the Main Rotor
AerodynamicsAerodynamicsVibrationsVibrationsNoiseNoise
Individual Blade Control (IBC)Individual Blade Control (IBC)Principle of OperationPrinciple of OperationEffects in Wind Tunnel and Flight TestsEffects in Wind Tunnel and Flight TestsIBC System DesignIBC System Design
Conclusion and OutlookConclusion and Outlook
Ku LX-E 28.10.04 Slide 60 Praxis-Seminar Luftfahrt Proprietary InformationZFLuftfahrtechnik GmbH
Conclusion
Helicopter versatile aircraftHelicopter versatile aircraftComplex aerodynamics of main rotor in Complex aerodynamics of main rotor in forward flight causes performance forward flight causes performance restrictionsrestrictionsadvanced main rotor blade control can advanced main rotor blade control can reduce reduce vibationvibation & noise and extend flight & noise and extend flight envelopeenvelopeextensive research work on IBC effects extensive research work on IBC effects has been donehas been doneworldworld--wide development wide development activitesactivites of the of the helicopter industry in the field of helicopter industry in the field of application to production helicoptersapplication to production helicopters