Verteilte Systeme und Sensornetze Drahtlose Sensornetzwerke in der Life Science Automation Ralf Behnke Ralf.Behnke@uni-rostock.de Institut für Angewandte Mikroelektronik und Datentechnik Dr. Frank Golatowski Frank.Golatowski@celisca.de Celisca
Gliederung Einführung Wireless Sensor Networks Potentielle Messungen in LSA Szenarien Gasmessung Lokalisierung Lokalisierung und Dienste 2
Wireless Sensor Networks Sensor Network Node: Tiny device capable of Sensing Computing Communication Sensor Network: Network of Sensor Nodes Exchanging data with each other Accumulating data at the sink Purpose: Ultra easy deployment in various areas Form factor: Reality Vision 3
WSN typische Anwendungen Anwendungszenarien Environment Observation Forest Fire surveillance Detection of vulcanic activity Flood protection Target tracking Driver assistance Human health 4
What makes LSA different? Common applications Outdoor Large area Dense deployment Only one or two parameters Life Science Automation Indoor Small area Many parameters Multi purpose Single purpose Inaccessible Environment 5
How LSA benefits from WSN? Classic sensors Wireless Sensor Networks Wired Wireless Unflexible Easy to deploy Fixed installation Easy to change installation Easy to extend Measuring in situ 6
Measuring in LSA Environments Direct measurements: Temperature process condition / storage condition Humidity Brightness Pressure e.g. in a glovebox Flow Gases process condition / reaction product / disaster prevention Vibration as progress indicator 7
Measuring in LSA Environments Temperature Gases Location 9
Current work Actual WSN installation Measuring Measuringtemperature Multihop Multihoprouting Illustration Illustration in in Webbrowser Webbrowser LIMS* LIMS* integrated integrated * Laboratory Information Management System 10
Use Case B Gas detection Sensor node detects gas leakage WSN raises an alarm Detecting persons in danger zone 11
Gassensoren Bereits vorhanden CO 2 detection Proprietäre Kommunikation Katalytisches Messprinzip In der Entwicklung Messung von CO, H 2 Standardisierte Kommunikation (ZigBee) Elektrochemisches Messprinzip 12
Auswahl an Gassensoren Katalytische Sensoren (Pellistor) Beheizte Spule Chemische Reaktion des Messgases erhöht Temperatur Messbare Änderung des Widerstandes Electrochemische Sensoren Messgas setzt bei chemischer Reaktion Elektronen frei Kleiner Messbarer Stromfluss Infrarot Sensoren Messgas absorbiert Licht bestimmter Wellenlänge Sensor enthält Lichtquelle und Lichtsensor
Use Case A Celisca Guide Initial situation Many complex devices in several rooms Persons interested in those devices Goal Provide information depending on user s location Provide information on mobile device Solution WSN for localization 14
Use Case A Celisca Guide Wearing a tag for localization Different location, different information 2 approaches Compare locations Detect proximity 15
Localization in WSN Main issue in WSN For networking Routing Clustering Mapping measurements src dest Two main categories Fine grained Multilateration Coarse grained Proximity, (Weighted) Centroid Localization 16
Localization in WSN Proximity Centroid Localization (CL) Average error: 18 % Maximum error: 45 % Weighted CL (WCL) Average error: 6.5 % Maximum error: 18 % 17
Lokalisierung Beispiel CL 20 0 5 x = 10 + 20 + 3 20 = 16,7 10 5 10 Beispiel WCL 10 20 x = 5*10 + 5*20 + 10*20 5 + 5 + 10 = 17,5
Durchgeführte Messungen Proximity Measurements Test environment Indoor LSA Distance: 1-14 m 140 120 100 0dBm (13m) - 10dBm (6m) 0dBm (13m) - 15dBm (5m) - 25dBm (4m) Results Proximity range detectable (3-4 m) Sufficient for use cases LQI 80 60 40 20 0 0 2 4 6 8 10 12 14 distance [m] 19
Current work Weighted Centroid Localization Testbed 4 beacons Beacon distance 43 m outdoor Results Mean error: 5.3 m (12 % v.s. 6.5 %) Max error: 13.1 m (30 % v.s. 18 %) Sufficient for LSA use cases (downscaled to indoor distances) Improvable by Modified measuring methods Modification of WCL Other localization algorithms 20
Switch to Dr. Frank Golatowski
Zusammenfassung LSA greatly profits from WSN Variety of phenomenas / measurement parameters Ultra easy deployment Picked temperature, gases and location for application Implemented temperature and CO 2 measurement First experiments with localization Appropriate to LSA use cases Currently working on CO and H 2 Sensors 22
Thanks for your attention 23