Wireless Network for Aircraft Control and Monitoring
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Transcript of Wireless Network for Aircraft Control and Monitoring
“Fly-By-Wireless”
Chris DimoulisCS 441
Fall 2013
Aircraft Systems (Current)Benefits of Wireless SystemCharacteristics and ObstaclesProposed Solutions
Cables and Pulleys Direct connection from flight controls to
control surface Hydraulic
Direct manipulation of hydraulic actuators in flight controls
Fly-By-Wire Avionics Full Duplex Switched Ethernet
(AFDX) used to send data from controls to actuators
View and manipulate flight and engine data\
Old Systems Pressure systems for altitude and airspeed Mechanical linkages for engine data
(tachometer and manifold pressure) New Systems
Full Authority Digital Engine Control (FADEC) Automatically controls engine parameters,
sends data to pilots through AFDX
Cost from Weight Reduction Cable costs: A320: $14MB787: $50M [1]
A380: 300 miles (500 km) of wire [2]
Weight reduction means better fuel efficiency and increased space for revenue weight
Improved Safety and Less Maintenance Less Wire degradation U.S. Navy: 78 aircraft made non-mission
capable due to wiring, 1000 aborts from wiring faults [2]
Wired interconnects and potential fires▪ B 747 tank explosion due to arcing between
fuel sensor wiring [3]
Real-Time and Deterministic [1]
Aircraft Network must behave in a predictable way
Current system provides 100Mbps Latencies must be bounded and
deadline constraints respected
Reliability and Availability Probability of failure needs to be 10-9 per
flight hour [1]
Fault Detection Long lifetime: Avionics system lifetime
can be 20 – 30 years [1]
Security [1]
Data confidentiality to prevent passive eavesdropping
Data integrity to guarantee data is not altered in transit
Prevent unauthorized access to network
Electromagnetic Compatibility[1]
Deployment is in a harsh physical environment
Large temperature and humidity changes along with vibrations
Intense radio frequency noise
Table reproduced from [1]
802.11n+Adequate Data rate+Uses Point Coordination Function for
contention free mode+Reliability: Automatic Retransmission
ReQuest (ARQ )- Not adapted for multicast[1]
- High possibility of interference from common devices[1]
ECMA-368 High Rate Ultra WideBand+Adequate Data rate and ranges+Distributed Reservation Protocol
TDMA (Contention free)
+More secure from “man-in-middle” than 802.11
Begin with a hybrid system Full Duplex Ethernet Switch to connect
clusters
Image reproduced from [1]
MAC Protocol Proposals Need predictable behavior under real-
time constraints▪ Synchronization protocol for TDMA
Reliability Mechanism for sending/receiving data▪ Probability of failure to be 10-9 per flight hour
Synchronization Protocol IEEE1588 Wired network synchronization
have been implemented within few nanoseconds precision
IEEE1558 has reached less than 200 nanosecond precision for wireless network synchronization, however too many messages
Proposed enhanced IEEE1588
Synchronization Protocol Master/Slave/Passive
node If slave node fails
passive node canfill in
Image reproduced from [1]
Reliability Mechanism Need adequate acknowledgement and
retransmission mechanism Communication is multicast▪ Multiple ACKs colliding?▪ Overhead from sender needing to receive all
ACKs
Reliability Mechanism Designated “leader”
of cluster ACK from leader,
NACK from rest If sender hears NACK
or nothing (due to ACK/NACK collision) then it will retransmit
Image reproduced from [1]
ECMA-368 can provide adequate data rate, contention free, and security properties
Needs predictable real-time behavior Enhanced IEEE1588 synchronization
Reliable data reception Cluster leaders with ACK/NACK
messages
[1] D. Dang, A. Mifdaoui,and T. Gayraund, “Fly-By-Wireless for Next Generation Aircraft: Challenges and Potential solutions.” (In Press: 2012) In: Wireless days conference, 21-23 Nov 2012, Dublin, Ireland
[2] R. K. Yedavalli, R. K. Belapurkar, “Application of Wireless Sensor Networks to Aircraft Control and Health Management.” Journal of control Theory & Applications. February 2011; 9(1):28.
[3] M. Panitz, D. Hope, W. Crowther, et al. “The opportunities and challenges associated with wireless interconnects in aircraft.” Proceedings Of The Institution Of Mechanical Engineers -- Part G -- Journal Of Aerospace Engineering (Sage Publications, Ltd.) [serial online]. April 2010;224(4):459.