Proactive monitoring in natural environments

Ian Marshall, Computing Laboratory, University of Kenti.w.marshall@kent.ac.uk

Technical Director of the Envisense Research centre

http://envisense.org

Current research methods• Single expensive

package• In situ process studies• Low spatial resolution• Short lifetime• Small areas

Wireless Sensor networks

• Ad-hoc wireless communication• Physical measurement• No access to mains• Large area (sq kms)• Long life (months)• Many measurement points

WSN management

• Low probability of manual intervention

• Highly dynamic, unpredictable environment

• Very unreliable nodes and comms• Need to automate response to

events• ‘model free’ adaptive control

Peak district Experiments

Floodnet

SECOAS

Scroby sands wind farm and its impact on sedimentation processes

CEFAS Survey

April 2002

Mechanical General Arrangement

Buoy (yellow)

Radio equipment

Data cable Warp

Chain

Chain

WarpPlough anchor

Real trial Oct-Nov 2004

Initial Deployment Areas

1 NM

6 Sensors150m apart

Shore station

Seabed Package

• Measure Oceanographic variables (15 minute cycle)

• Temperature (1 sample/min) • Pressure (1 sample/s for 5 mins)• Turbidity (10 samples/min)• Tilt (aka current) - (1 sample/s for 5 mins)• Conductivity (1 sample/min)

• Adapt sampling rates • Adaptively log data• Transmit selected data to radio buoy

Adaptive sampling

• Measure, delete, combine, forward, sleep• Use local variability, neighbour variability and

internal state • Self configure using distributed evolutionary

“algorithm” (bacteria)• Can adjust priorities and frequency of actions• Can form groups (quorum sensing)• Reward set by user using a diffusion (gossip)

protocol – changes drive auto-reconfiguration of genome

QoS on a Sensor Network

Processing

Summary

• Autonomous adaptive control is needed in environmental sensor networks

• Network protocols must support and respond to application semantics (be app aware)

• In simulation adaptation was almost as good as optimal sliding window

• In practice it dealt well with change from calm to stormy

• More research will be needed• www.secoas.org• www.envisense.org