University of MinhoSchool of EngineeringDep. Industrial Electronics

A Bluetooth-based Wireless Distributed

Data Acquisition and Control System(1)Ezequiel Coelho, (1)Paulo Carvalhal, (1)Manuel Ferreira, (2)Luís Silva, (2)Heitor Almeida, (1)Cristina Santos and (1)José Afonso

(1)Department of Industrial Electronics(2)Department of Mechanical Engineering University of Minho, Guimarães, Portugal

pcarvalhal@dei.uminho.pt

http://aiva.dei.uminho.pt

University of MinhoSchool of EngineeringDep. Industrial Electronics

motorflaps flaps

ailerons ailerons

rudder

elevator elevator

GPSIMU

attitude

motor

Conventional Cable Approach

•High computational power•Functional & requirement upgrades are difficult

•High volume cabling & potential cabling problems•Complex electronics

University of MinhoSchool of EngineeringDep. Industrial Electronics

Snapshot

motor motorflaps

flapsailerons ailerons

rudder

elevador elevador

GPSIMU

attitude

•Easy upgrades•Simpler electronics•High modularity

•Cable elimination•Flexible architecture

University of MinhoSchool of EngineeringDep. Industrial Electronics

Global aircraft architectureon board instrumentation

GPS Inertial Measurement Unit 6 point aero-dynamical probe

Wind speed, α β angles, altitude, barometric pressure Radio Altimeter (automatic landing system) Temperature (Onboard electronic modules) Servo Actuators

2 Flaps 2 Ailerons 2 Elevators 2 Rudders

2 Electric Motors for aircraft propulsion

University of MinhoSchool of EngineeringDep. Industrial Electronics

Global system architecture on board architecture

BluetoothPiconet

master

EVS

Producer/Consumer

Producer/Consumer

Earth Station

Bidirectional Ground Station Communications

Link

DataLogger&

EarthLink

Flight Controller

Local multi-access Interconnect

University of MinhoSchool of EngineeringDep. Industrial Electronics

Global system architectureCommunications model

Physical platform

AIVA application

Transport services

Flight Controller

Ground LinkGround Link

Physical platform

AIVA application

Transport services Telemetry

Monitor Simulator

Local network communications

Ground Station

Bluetooth Network

MasterSlave(s)

Layered architectureFlexible projectReduce maintenance and future upgrades

University of MinhoSchool of EngineeringDep. Industrial Electronics

Global system architectureVirtual machine advantage

Master

Slave 7

Slave 6

Slave 5

Slave 4

Slave 3

Slave 2

Slave 1

Bluetooth stack interaction at application levelBluetooth complexity details can be ignoredBetter function integrationDesigner focus is on wireless application only

point-multipoint approach(Wireless MultiDrop)

Performance is affectedLimited functionality

University of MinhoSchool of EngineeringDep. Industrial Electronics

Global system architecture Experimental results

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•Experimental setup: 6 slaves, uplink constant bit rate traffic, 15 byte packets, balanced mode.•The developed system is able to reach a sampling rate of 200 Hz for all slaves simultaneously without performance degradation.

University of MinhoSchool of EngineeringDep. Industrial Electronics

Global system architecture Experimental resuslts

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Sampling Rate (Hz)

Del

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Mean Minumum Maximum Std. Dev.

•The delay is not adversely affected by a rise in the offered load, as long as the network operates below the saturation point.•The mean delay is around 27 ms.•The delay is lower than 90 ms for 99% of the samples.

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