3. The first step towards fly-by-wireless control systems is likely
to be the introduction of wireless sensor networks (WSNs).
A typical commercial/military aircraft consists:
1: Safety-critical systems, such as aircraft engine control
system, aircraft flight control systems
2: Non safety critical systems, such as structural and engine
health monitoring systems, aircraft cabin environmental control
system, inflight entertainment system, etc.
INTRODUCTION
4. Current systems based on wired connections:
1. Complex
2. Difficult to route
3. Heavy and prone to damage
The Airbus A380 for instance has:
1. 300 miles of cables
2. 98,000 wires
3. 40,000 connectors
CONTI……
5.
6. So with Replacement of the current wire harness-based
sensors with (WSN) we can achieve:
Reduce the aircraft system weight.
Increasing the number of sensors.
Improved fuel efficiency and reduced carbon emissions.
Reduction in direct costs.
In a recent study, that the use of a WSN can results:
90 lbs. weight reduction of Cessna 310R control systems.
Increases its range by around 10%.
CONTI…..
9. WSNs consists:
Cluster of intelligent sensors designed to monitor
physical parameters vibration, temperature, strain,
pressure, etc.
Each sensor node within the network performs the
function like sensing, data processing and wireless data
transmission.
Use of microelectromechanical systems (MEMS)
technology enables:
production of low-cost, low-power multifunctional sensors
having very small size and light weight.
APPLICATIONS OF WSNs FOR AIR
CRAFT SYSTEMS
10. The present aircraft engine control systems are based on a
centralized architecture known as (FADEC).
Heavily shielded analog wire harnesses are used b/w
sensor/actuator nodes and FADEC.
Which imparts a heavy weight penalty and high
maintenance cost.
Before implementing WSN for AEC an intermediate step is
distributed control architecture.
In distributed engine control (DEC), the functions of
FADEC are distributed at the component level.
Each sensor/actuator is replaced by a smart sensor/actuator.
Distributed Aircraft Engine Control
11. These smart modules include local processing
capability to allow and diagnostics and health
management functionality.
DEC allows the implementation of advanced engine
control technologies:
Active clearance control, active stall and surge
control, active combustion control.
Which will improve aerothermodynamic efficiency,
lower emissions and also help to reduce the control
system weight.
Initially, WSN can be used only for the redundant
sensors of DEC systems. An ideal DEC architecture,
which will make use of the advantages of WSN, will
have actuators with wired connections in order to
provide a secure reliable control system architecture.
CONTI……..
12. An aircraft engine is a complex system requiring regular maintenance to
ensure flight safety. Engine maintenance, repair and overhaul (MRO)
operations are time consuming and costly.
Hence, in order to improve the time-on-wing of aircraft engines, it is
desired to perform condition-based maintenance, which uses real-time data
to schedule maintenance.
Use of WSN for aircraft engine health monitoring will enable
implementation of condition-based monitoring algorithms due to availability
of real-time data.
Each of the sensor nodes of the WSN will communicate with an on board
diagnostics and health monitoring system, which will
store the data points for the entire flight.
Once on ground, this data will be transmitted to the maintenance workshop
through wireless communication.
This will allow the use of online as well as offline diagnostic algorithms.
WSN FOR AIRCRAFT ENGINE
HEALTH MANAGEMENT
13. The aircraft flight control systems consists:
1: Flight control surfaces 2: cockpit controls 3: sensors and
communication linkages b/w 1 & 2 actautors.
Although the use of fly-by-wire(FBW) reduces the weight but system
is still bulkier.
Intelligent flight control systems (IFCS) are being developed to safely
control the aircraft in the presence of structural damage.
Increasing the number of sensors, without a substantial increase in
weight is possible only by implementation of WSN.
WSN will enable integration of several systems into one.
The use of WSN for both aircraft engine control and aircraft flight
control will allow integration between flight control and propulsion
control, which can significantly improve performance of military
aircrafts as well as UAVs.
FLY-BY-WIRELESS AIRCRAFT
FLIGHT CONTROL SYSTEMS
14. One of the other advantage of
using fly-by-wireless flight
control systems based on
WSN is :
If the pilots or flight deck
controls become inoperable
or incapacitated, ground-
based air traffic control
(ATC) or adjacent military
aircraft with necessary
electronics, can control the
aircraft.
CONTI………
15. The increasing use of composite materials for aircraft structures, it is
necessary to develop novel methods for aircraft structural health monitoring.
Most of the failures of the laminated composite structures originate with
delamination of layers, and for metal aircraft structures, cracks are
developed in metal structures which grow over time leading to failures.
For both of these cases, visual inspection is not a reliable method for failure
detection. This calls for a vibration analysis-based failure detection method.
WSN can be embedded into the composite structure which will harvest the
vibration energy and will transmit the real-time data to the central health
monitoring unit.
These sensors will be used to monitor the internal parameters like cracks,
strain as well as external parameters like temperature, load, etc.
WSN FOR AIRCRAFT STRUCTURAL
HEALTH MONITORING
16. Aircraft Hydraulic Monitoring Systems:
These systems play a very important role in powering
primary and secondary flight control systems as well as
several other like wheel brakes, cargo doors, loading
ramps, etc.
By replacing the conventional sensors by WSN, it will be
possible not only to display the signals to the gages in
cockpit, but also to the ground servicing personnel for
conducting on-wing aircraft engine maintenance.
Environmental Control Systems:
(ECS) provide air supply with optimum humidity and
sufficient oxygen concentration to the passengers and crew
and are also used for thermal control of the avionics, fuel
and hydraulic systems.
Use of WSN for ECS will help to increase their reliability
as well to improve the efficiency of the aircraft engines.
OTHER NON SAFETY CRITICAL
SYSTEMS
18. Emergency systems:
Use of WSN for smoke and fire detection systems,
emergency lighting systems, passenger address systems,
etc.
Can help to reduce the weight and wiring complexity of
these systems along with increasing their reliability.
CONTI………
19. Research needs to be conducted in the area of information
fusion of wireless sensor networks for aircraft systems.
Energy harvesting methods needs further improvement
in the terms of efficiency and reliability.
Development of high temperature electronics will enable the
use of WSN for aircraft engine control and health
monitoring.
A dedicated global spectrum for WSN for aircraft applications
needs to be developed.
New wireless aircraft certification regulations needs to
be developed to address the various security and safety
threats.
Future Enhancements