Combining advanced sensor technologies, with optimised data acquisition and diagnostic and prognostic capability,
structural health monitoring (SHM) systems provide real-time assessment of the integrity of bridges, buildings, aircraft,
wind turbines, oil pipelines and ships, leading to improved safety and reliability and reduced inspection and maintenance
costs. The implementation of power harvesting, using energy scavenged from ambient sources such as thermal gradients
and sources of vibration in conjunction with wireless transmission enables truly autonomous systems, reducing the need
for batteries and associated maintenance in often inaccessible locations, alongside bulky and expensive wiring looms.
The design and implementation of such a system however presents numerous challenges. A suitable energy source or
multiple sources capable of meeting the power requirements of the system, over the entire monitoring period, in a
location close to the sensor must be identified. Efficient power management techniques must be used to condition the
power and deliver it, as required, to enable appropriate measurements to be taken. Energy storage may be necessary, to
match a continuously changing supply and demand for a range of different monitoring states including sleep, record and
transmit. An appropriate monitoring technique, capable of detecting, locating and characterising damage and delivering
reliable information, whilst minimising power consumption, must be selected. Finally a wireless protocol capable of
transmitting the levels of information generated at the rate needed in the required operating environment must be chosen.
This paper considers solutions to some of these challenges, and in particular examines SHM in the context of the aircraft