(Image courtesy of iStockphoto)

NPL has worked with wireless sensor network developers, Senceive, to help them understand their measurement challenges, and improve their products.

Wireless sensor networks (WSNs) are groups of sensors that collect, process, and send information about the environment around them. Depending on their design, they can collect information on temperature, pollution levels, sound, vibration, pressure, location and many other quantities. They are used in many areas of measurement, security, structural health monitoring, and environmental monitoring.

One of the main barriers preventing their use in new, safety-critical, applications is the difficulty of proving the accuracy of the sensors' results. One way to improve confidence in a sensor's output is to check it against another sensor. By combining the data gathered with a model of the system you can predict what an individual sensor should be reading and hence check how reliable the sensors' measurements are.

Senceive's main application area is long-term infrastructure monitoring, particularly in transport and heritage. Their WSNs are highly complex embedded systems, meaning it can be a challenge to quantify the uncertainties involved.

Senceive needed NPL's help to improve their tilt sensing system, and verify its accuracy. This system was designed for structural health monitoring-type applications, so generating reliable data is critical.

Building upon work in self-validation and data fusion, NPL characterised Senceive's tilt sensors' output, in terms of linearity, jitter and overall uncertainty. NPL also advised Senceive on system improvements and on future deployments.

This has given Senceive a greater understanding of the measurement issues they face, and prepared them for an upcoming large-scale deployment.

"Working closely with Michael Collett and tapping into the great depth of expertise at NPL has been invaluable in helping us understand the measurement challenges we are faced with, and enabled us to incorporate some significant improvements into our system design."

- Michael Gois, CTO Senceive Ltd

Read the full technical case study here.

For further details, please contact Michael Collett.

Find out more about NPL's work in Electromagnetics and Communications technology.