MEC 3716 FLIGHT DYNAMICS and CONTROL
Longitudinal Control
Longitudinal Control
Control of aircraft can be achieved by providing an incremental lift
force on aircraft lifting surfaces (control surfaces)
Control surfaces are located at some distance for air
MEC 3716 FLIGHT DYNAMICS and CONTROL
Automatic Control Theory
The Classical Approach
Introduction
Control theory
deals with the analysis and synthesis of logic for the control of system
Classical approach
Modern approach
Analytical approach based on:
Anal
MEC 3716 FLIGHT DYNAMICS and CONTROL
Automatic Control Theory
The Classical Approach
Introduction
Control theory
deals with the analysis and synthesis of logic for the control of system
Classical approach
Modern approach
Analytical approach based on:
Anal
MEC 3716 FLIGHT DYNAMICS and CONTROL
Lateral Motion (Stick-Fixed)
(Stick-
Pure Rolling Motion
Roll Angle
Rolling Moment
From the Newtons 2nd Law :
rolling moments
L
cg
= I x
= I x
L
L
A +
p = I x
A
p
due to the ailerons deflection
roll-damping mome
MEC 3716
FLIGHT DYNAMICS AND CONTROL
Mechanical Engineering department
Kulliyyah of Engineering
International Islamic University Malaysia
Introduction
Flight dynamics is the study of orientation of air and space vehicles
and how to control the critical fl
MEC 3716 FLIGHT DYNAMICS and CONTROL
Longitudinal Motion (Stick-Fixed)
(Stick-
State Space representation
Linear equation of Longitudinal motion
u = X u u + X w w + g cos( 0 ) + X E E + X T T
1 cfw_
Z u u + Z w w + (u 0 + Z q ) q + g sin( 0 ) + Z E E + Z
MEC 3716 FLIGHT DYNAMICS and CONTROL
Longitudinal Motion
SecondSecond-Order Differential Equations
SecondSecond-Order Differential Equations
To illustrate the properties of a second order differential equation, consider the
mechanical system composed by
m
MEC 3716 FLIGHT DYNAMICS and CONTROL
Directional Stability
Definition
Directional or weathercock, stability is concerned with the
static stability o f a irc ra ft a b o u t th e z -a x is
X
V
Y
Stability Condition
To have static directional stability, the
MEC 3716 FLIGHT DYNAMICS and CONTROL
Directional Stability
Definition
Directional or weathercock, stability is concerned with the
static stability of aircraft about the z-axis
X
V
Y
Stability Condition
To have static directional stability, the aircraft mu
MEC 3716
FLIGHT DYNAMICS AND CONTROL
Mechanical Engineering department
Kulliyyah of Engineering
International Islamic University Malaysia
Wing Contribution
LW
Wing Mean Chord
DW
CG
W
ZC G
Fuselage Reference Line
Xac
iW
W
Direction of Flight
MEC3716 Week -
MEC 3716 FLIGHT DYNAMICS and CONTROL
Aircraft Equation of Motion
Derivation of Rigid Body Equation of Motion
THE AXES and NOTATION
X,u
x
Longitudinal Axis
l,p
Y,v
y
m,q
Lateral Axis
n,r
Z,w
Normal Axis
u,v,w
X,Y,Z
p,q,r
l,m,n
are Velocities
are Forces
are
MEC 3716 FLIGHT DYNAMICS and CONTROL
Automatic Control Theory
Modern Control Theory
State Space Modeling
the state-space approach to control system analysis and design
is a time-domain method
the application of state variable techniques to control probl