Structural Health Monitoring Using Smart Sensors - ideals ...

9.2.7 Communication range adjustment
When the communication range of a smart sensor includes neighboring sensor
communities, the communication range should be shortened to reduce RF interference.
When two sensor communities are out of communication range of each other, these
communities can perform communication in parallel without interfering with each other.
Communication range adjustment results in faster execution of DCS and smaller power
consumption.
9.2.8 Reliability of the system
For the system to be used for years, the reliability of smart sensor nodes needs to be
improved. In the current system, the Imote2s sometimes hangs up. The possibility of
hang-ups should be reduced.
Additionally, node failure tolerance should preferably be realized, because the
possibility of node failure cannot be completely eliminated; for example, even a PC with
better resources sometimes hangs up. Failure of a single node should not provoke failure
of the entire system.
Even when all of the nodes seem to be working, sensor signals may be erroneous. For
example, sensors may not be firmly attached to a structure. Such Byzantine-type error can
possibly be detected by checking the linearity between measured signals. When the
linearity between two signals is much lower than that of other pairs, one of the two signals
may come from a sensor which is not adequately installed. Implementation of such a
Byzantine error detection algorithm can improve the reliability of the damage detection
system.
9.2.9 Environmental hardening
The Imote2 needs to be packaged before the node can be installed on full-scale
structures, especially when the Imote2 is used outside. The package needs to protect the
Imote2 from weather, birds, insects, etc. Attention needs to be paid to not blocking radio
reception/transmission. Also, the packaging should not absorb or amplify vibration.
9.2.10 Multiple purpose usage of smart sensors
Smart sensor networks can potentially serve multiple purposes, while the developed
SHM framework currently serves only for SHM purposes. Smart sensors can be used for
traffic monitoring, local weather monitoring, fire detection, etc. Integration of these
services enhances the value of smart sensors and makes introduction of smart sensor
systems more attractive from a cost-benefit perspective.
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