EE 5320 Project 1 Summer 2006 Design and Analysis of Aircraft Control Systems

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Nov 16, 2013 (3 years and 11 months ago)

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1

EE 5320 Project

1

Summer

2006

Design
and Analysis
of Aircraft Control Systems




Objective:

It is well known that the pilot’s efforts can be greatly reduced by introducing
feedback signals into the flight control channels. The determination of these feedb
ack
signals repr
esent

the control problem
s

discussed here.


The usual method of attack is to separate the aircraft’s equation of motion into two
uncoupled modes, a longitudinal and a lateral mode.


The technique
s

described in
this project

are

systematic an
d efficient method
s

for
designing multi
-
variable controllers based on well k
nown results in classical,

as well as
modern control t
heory. The methods would yield

multi
-
loop system
s

in which a linear
combi
nation of all aircraft states are

feed
-
back in each c
ontrol channel, consequently,
every feasible feedback path will be considered.


Important:

Final project report

(individually done)

w
ill be due
07/31/06

Midnight
.

Email the soft copy of the report to
jyotir@arri.u
ta.edu
, copy to
dvrabie@arri.uta.edu
,
and
pballal@arri.uta.edu



Sample report format is posted here


(
http://arri.uta.edu/acs/jyotirmay/EE4343/Labs_Projects/project
reportformat.doc
).


This document will be updated
frequently;
new steps will be added

along with the
relevant material covered in the class.
No intermediate repor
ts are required.

Project 1
weighs 100
% towards project grade.








2

Aircraft

Dynamics

are give
n by

(See appendix for the

definitions).


R
R
A
A
r
p
R
R
A
A
r
p
R
R
A
A
r
p
E
E
q
u
E
E
u
E
E
u
N
N
r
N
p
N
N
L
L
r
L
p
L
L
V
Y
V
Y
V
g
r
V
Y
p
V
Y
V
Y
M
q
M
M
u
M
V
Z
q
V
Z
u
V
Z
X
g
X
u
X
u












































































1


Primer

(Not for submission)

What are lateral and longitudinal dynamics of a system in
motion?

When lateral and longitudinal dynamics of a system in motion can be decoupled?

What

do Aircraft

system states
physically mean?

What
does phugoid motion

physically mean?



Project Assignment


For aircraft longitudinal dynamics
,

1.

Identify system states; classify them into rates and positions.

2.

Identify system control inputs.

3.

Write lin
ear system state
space equation in the form
Bu
Ax
x



.

4.

Make a signal flow diagram of aircraft longitudinal dynamics.

5.

Find the resolvant matrix.

6.

Obtain the characteristic polynomial.

7.

Find the system poles using the data in the Table 1, you will observe two shor
t
period
modes (
real poles), and a phugoid
mode (
complex pole pair).

8.

Find the damping and frequency of the phugoid motion

using the data in the Table
1
.

9.

The speed variations in aircraft longitudinal motion are often “trimmed” by a
separate throttle control

so that
u

can be assumed negligible. Thus we can use a
simplified dynamic model in which the state variables are



1
x


q
x

2




3
x

Using these state variables and aerodynamic coe
fficients of Table 3, find the gains
that place the closed loop poles in the pattern:
2


s
,
3
1
j
s



.

10.


Draw the block diagram of the closed loop system achieved in the previous
problem.


For aircraft lateral dynamics

11.

Ident
ify system states; classify them into rates and positions.

12.

Identify system control inputs.


3

13.

Write linear system state space equation

in the form
Bu
Ax
x



.


14.

Make a signal flow diagram of aircraft longitudinal dynamics.

15.

The eigen values for the

lateral motion of an aircraft consist, typically, of two
complex poles with relatively low damping, and a pair of real poles. The complex
pair defines a mode called dutch roll. One real pole, relatively far from the origin,
defines a mode called roll subs
idence, and a real pole near the origin defines the
spiral mode.
(The

latter is sometimes unstable
-
spiral divergence.) Using the data
given in table 2 find the four modes of the aircraft.

16.

A stability augmentation system (SAS) is to be designed for this air
craft using
two rate gyros, each of which measures one of the body rates
p

and
r

.Find the
transfer functions

( use the data given in Table 2).

)
(
)
(
s
s
p
A


)
(
)
(
s
s
r
A


)
(
)
(
s
s
p
R


)
(
)
(
s
s
r
R


Is it apparent f
rom these transfer functions why the ailerons are used for roll (
p
)
control and the rudder is used for yaw (
r
) control? Write your observations.

17.

Is the dynamic process controllable using only the ailerons?

( use the data given in
Table 2, write your observ
ations in support of the answer)

18.

Is the dynamic process cont
rollable using only the rudder
? ( use the data given in
Table 2, write your observations in support of the answer)
.

19.

The rudder is often used for turn coordination; we may thus assume a control law

for the rudder.




























T
V
Y
p
V
Y
r
V
Y
V
g
V
Y
V
Y
p
r
A
A
R
R
1
1

(a)

Using the aerodynamic data of table 2, find the control law for the ailerons that
makes the sideslip decay constant
2
.
0

T
s and places the remaining poles at
1


s

and
3
1
j
s



.


20.


Combine the result with (a) to obtain the entire control law
Kx
u


.




4

Appendix A:

Aerodynamic Variables

and parameters

deflection
elevator
:

deflection
aileron

:
deflection
rudder

:
angle

yaw

:
angle

roll

:
rate

yaw

:
rate

roll

:
pitch

:
rate
pitch

:
speed
in

change

:
angle

slip

slide

:
attack

of

angle

:
E
A
R
r
p
q
u











Table 1
:
Aerodynamic parameters for AFT
-
16 on landin
g approach



Kt
V
139




0507
.
0


u
X

861
.
3



X


0

E
X

00117
.
0


V
Z
u

5164
.
0


V
Z



0717
.
0


V
Z
E

000129
.
0


u
M

4168
.
1


M

4932
.
0


q
M

645
.
1


E
M


Table 2: Aerodynamics data for a fighter aircraft

( Lateral Dynamics)


746
.
0


V
Y


006
.
0

V
Y
p

006
.
0

V
Y
r

0369
.
0

V
g

0012
.
0

V
Y
A

0092
.
0

V
Y
R

9
.
12



L

746
.
0


p
L

387
.
0

r
L


05
.
6

A
L

952
.
0

R
L

31
.
4


N

024
.
0

p
N

174
.
0


r
N


416
.
0


A
N

76
.
1


R
N


Table 3: Aircraft lon
gitudinal dynamics, simplified


1


V
Z


1
.
0


V
Z
E


5
.
0


q
M

5



M

9


E
M

14



X

1


E
X





5

EE 5320

Project 2


Summer

2006

Workshop: Contro
l System Design Tools





Real
-
Time Targets enables to run software models in real time on the desktop for rapid
prototyping or hardware
-
in
-
the
-
loop simulation
of control system and signal processing
algorithms.


This workshop’s objective is to develop an ability to create and control a real
-
time
execution entirely through software/hardware tools. Using these tools, a source code can
be generated, compiled; this

facilitates real
-
time execution on a Windows PC while
interfacing to real hardware using PC I/O boards.


I/O device drivers are included to support a selection of I/O boards, enabling attendees to
interface to sensors, actuators, and other devices for exp
erimentation, development, and
testing of real
-
time systems.


Demonstrations will include
-

interfacing with some of the electromechanical systems,
identification, modeling and design of controllers. Available implementation platforms
will be discussed.


Ke
y Features




Run models in real time on desktop PC.



Provides fast point
-
by
-
point processing of data for minimal latency, a requirement
in control system applications.



Works with PC I/O boards for real
-
time input and output.



Enables control of real
-
time mod
el execution directly from the software, creating
a "PC
-
in
-
the
-
loop" prototyping environment.



Enables signal acquisition and parameter tuning.



Includes a C compiler for building the real
-
time code.


6




Industrial Emulator


Spring
-
Mass Damper


Inverted Pendulum


Torsion Control System


Figure: Electromechanical Systems