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时间:2010-08-12 14:27来源:蓝天飞行翻译 作者:admin
曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

are coupled in speed and altitude
• Pilots have learned through training to
decouple flight path and speed control
• Current automatic control modes fail
to account for this control coupling:
its operation is like giving
- throttle to one pilot to control speed
- elevator to other pilot to control flight path
γ +v􀀅/g
γ −v􀀅/g
• Elevator and thrust control are ~orthogonal
• Throttle controls Total Energy Rate:
• Elevator controls Energy Distribution: }This Energy Strategy used to
achieve “pilot-like quality”
in automatic control
Flight Dynamics - Energy Control
Relationships
Drag
g
Thrust W v REQ = ( 􀀅 + sinγ ) + •
• current autothrottles neglect largest term: Wsinγ
• trim thrust in level flight is equal to Drag

• thrust changes produce
• elevator produces energy redistribution
• conclusion: energy is the right control integration strategy
V
E
g
W v t ( 􀀅 + sinγ ) = 􀀅
2
2
1 V
g
E W h W t = ⋅ + ⋅ ⋅
( − sinγ )
g
W v􀀅
Total Energy Control System
(TECS)
• concept
• thrust controls Total Energy requirement
• elevator controls distribution of energy
• result: generalized multi-input / multi-output control strategy
•speed /flight path mode errors are normalized into
energy quantity, fed forward to throttle and elevator:
• provides decoupled command responses
• consistent/energy efficient operation in all modes
• control priority when thrust limits:
• generally speed control has priority
• exception: glide slope / flare mode
• Vmin/Vmax envelope always protected
• Vcmd limited to Vmin/Vmax
• control authority allocation: handles complex maneuvers
Generalized Integrated Automatic
and Manual FBW Control
MODE CONTROL
PANEL
FMC
IRU
CDU
THROTTLE
ELEVATOR
ACTUATOR
ENGINE
PATH MODES
FEEDBACK
NORMALIZATION
SPEED MODES
FEEDBACK
NORMALIZATION
COMMANDS
COORDINATION
FEED FORWARD
COMMANDS
PROCESSING
THRUST
SCALING
PITCH
INNER
LOOP
INTEGRATED FLIGHT GUIDANCE
& CONTROL COMPUTER
C γ
g
v􀀅 C
COLUMN.
EE
C
ADC
TECS Functional Architecture
and Mode Hierarchy
􀁄 􀁄
􀁄
􀁄
􀁄
􀁄
􀁄 􀁄 􀁄
􀁄
􀁄 􀁄 􀁄
􀁄 􀁄 􀁄 􀁄
􀁄
􀁄 􀁄
Altitude
Glide Slope
Vert. Path
IAS
Mach
Time Nav
Flight path
Angle
Flare
Go Around
Manual FBW
Vmax
Vmin
V
.. Kh
Kv 1/g
V
Rate
Limit
Rate
Limit
Generalized
Thrust and
Elevator
Commands
Coordination
􀀅v_
c
g
Tc
V
δe
c
Kv 1/g
Kv 1/g
energy control energy rate control
􀁄 􀁄􀁄
􀁄 γc
􀁄
TECS Core Algorithm
Energy Rate Control
Engine
Control Engine
(TLIM). (PATH PRIORTY)
Pitch
Innerloop
Control
Actuator
KTI
S
KEI
S
KTP
KEP
(TLIM). (SPEED PR)
2-K
K
+
+ _ +
+
_
+
_
+
+
+
+
+_
+
_
Weight
Airplane independent design Airplane tailored design
T
δe
γ
γc
􀀅v_g
Specific Net Thrust
Command
Pitch Attitude Command
(typically)
􀀅 v
c _
g
(E􀀅 )
Dε SN
(E􀀅 )
Tε SN

Control Authority Allocation
Example
• Maneuver Authority
• During climb at Tmax , Vc /g limited to
, allowing speed cmd execution by
reducing climb gradient temporarily by half
• During descent at Tmin , V/g is limited to
, allowing speed reduction
by temporary level off
.5 (— + γ ) .
Vg
1.0 (— + γ ) .
Vg
= (— + γ ) .
Vg
.

Envelope Protection Functions
• Airspeed: keep between Vmin and Vmax, preferably at IAScmd
 
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