SUBMITTED BY
PRAMOD H S
DEPT OF MECHATRONICS
JSS POLYTECHNIC
NANJANGUD
HISTORY OF FBW
Electronic signaling of the control
surfaces was tested in the 1950s.
This replaced long runs of
mechanical and hydraulic connections
with electrical ones.
The first digital fly-by-wire aircraft
to take to the air (in 1972) was
an modified electronically
 The
term "fly-by-wire" implies a purely electricallysignaled control system.
 It
is used in the general sense of computer-configured
controls.

where a computer system is interposed between the
operator and the final control actuators or surfaces.
 This
modifies the manual inputs of the pilot in
accordance with control parameters.

Fly-By-Wire was designed so that the pilot moves his
controls that provided electrical inputs into a computer.

The computer then uses information from other inputs
and then calculates the proper control changes.

This command is transmitted by WIRE to an actuator or
a servo back to the wing/tail which moves the control
surface.
INNER VIEW OF AN FBW

Fly-by-wire
control
systems
allow
aircraft
computers to perform tasks without pilot input.
Automatic
stability
systems
operate
in
this
way. Gyroscopes fitted with sensors are mounted in
an
aircraft
to
sense
movement
changes
in
the pitch, roll and yaw axes. Any movement (from
straight and level flight)
REFERENCE
MEASURED
+ ERROR
CONTROLLER
SYSTEM
INPUT
-
MEASURED
OUTPUT
SENSOR
SYSTEM
SYSTEM
OUTPUT
THERE ARE TWO TYPES OF SYSTEMS IN
FBW THEY ARE

ANALOG SYSTEM

DIGITAL SYSTEM



Fly-by-wire
replace
hydromechanical
or
electromechanical
flight
control
systems
with electronic circuits.
The control mechanisms in the
cockpit now
operate signal transducers, which in turn generate
the appropriate electronic commands.
These are next processed by
controller with an analog signal.
an
electronic




A digital fly-by-wire flight control system is similar
to its analog counterpart.
The signal processing is done by digital computers
and the pilot literally can "fly-via-computer". It
increases the flexibility of the flight control system.
The digital computers can receive input from any
aircraft sensor.
This also increases the electronic stability, because
the system is less dependent on the values.
This eliminates mechanical contacts.
The mechanical contacts are replaced by wires
Due to the elimination of the mechanical contacts wear and
tear is reduced.
The control system used in this type is far more intelligent
then the conventional system.
APPLICATIONS OF DIGITAL FBW


The F-8 digital fly-by-wire program served as the
springboard for DFBW technology to be used in both
military and civilian aircraft.
satellite manufacturers also routinely
technology in their vehicles and spacecraft.

Space Shuttle

Several unmanned aerial vehicles (UAVs)
use
the
Analog system
Digital system
1)
Accuracy low
1) Accuracy high
2)
Circuit Complication
2) circuit is simplified
3)
Calibration is tough
3) calibration is easy
This system has less or no drawbacks. But some of the
people argue that the system containing software program is
never free of troubles rather how many times it is been
checked or serviced. Rather then software the failures of
sensors may also be trouble. But this problems are not
considered because the sensors are highly precise and
developed for these types of system.
ADVANCED AEROPLANES WHICH ARE BASED ON FBW
SUKHOI-47
TYPHOON
F-22 RAPTOR
MI-35

Fly-by-wireless

Power-by-wire

Fly-by-optics

Higher accuracy

Due to the elimination of the mechanical contacts wear
and tear is reduced.

The control system used in this type is far more
intelligent then the conventional system.