HR: 1330h
AN: S42B-0166    [PDF]
TI: Wireless Structural Sensing for Health Monitoring and Control Applications
AU: * Lynch, J P
EM: Jerome.Lynch@umich.edu
AF: University of Michigan, Department of Civil and Environmental Engineering, 2328 G. G. Brown, 2350 Hayward Street, Ann Arbor, MI 48109
AB: The economic and societal impact of civil structures under-performing during large earthquakes can be significant. While in recent years the structural engineering community has made great strides in advancing knowledge of structural behavior under extreme loads, a need still exists for the rapid assessment of structural performance during seismic events. Numerous options are commercially available to facility owners who wish to install a structural monitoring system within their structures. However, these structural monitoring systems are defined by their use of coaxial cables for the transfer of response measurements from sensors to centralized data servers. The installation and maintenance of cables within a civil structure often drive system costs high thereby preventing widespread industry adoption. In response to these limitations, the integration of information technologies such as wireless communications and microcontrollers have been explored for the creation of alternative structural monitoring systems defined by low installation costs and decentralized computational frameworks. In particular, a novel wireless structural monitoring system assembled from a dense network of inexpensive wireless sensing units has been designed and fabricated. The wireless sensing unit architecture consists of three functional components: a data acquisition interface for the collection of data from attached sensors, a computational core for data interrogation, and a wireless communication channel for the transfer of data to the sensor network. The use of wireless modems drastically reduces the efforts and costs of system installations rendering the technology attractive for widespread adoption in a broad class of civil structures. A second innovation of the system is the inclusion of computational power within each wireless sensing unit allowing for local execution of embedded engineering analyses. In particular, analyses for the detection of damage in structures (structural health monitoring) have been included in the unit's computational core. Additionally, an actuation interface has recently been added to the sensing unit design to allow for direct operation of structural actuators. With a computational core capable of real-time data processing, the data acquisition and actuation interfaces can be coupled through discrete-time feedback control loops implemented in software. Looking to the future, this intelligent monitoring infrastructure can possibly tune a structural control system in real-time after early warning of a pending seismic disturbance has been communicated to the wireless sensor network.
DE: 7212 Earthquake ground motions and engineering
DE: 7294 Instruments and techniques
DE: 7299 General or miscellaneous
DE: 9805 Instruments useful in three or more fields
SC: Seismology [S]
MN: 2003 Fall Meeting