3. 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
4. The term "fly-by-wire" implies a purely
electrically-signaled 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.
5. 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.
8. 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)
10. THERE ARE TWO TYPES OF SYSTEMS IN FBW THEY ARE
ANALOG SYSTEM
DIGITAL SYSTEM
11. 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 an electronic
controller with an analog signal.
12. 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.
13. 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.
14. 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 use the
technology in their vehicles and spacecraft.
Space Shuttle
Several unmanned aerial vehicles (UAVs)
APPLICATIONS OF DIGITAL FBW
15. 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
16. 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.
19. 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.
