Decentralization of Wireless Monitoring and Control Technologies for Smart Civil Structures

A smart civil structure is defined by sensing and/or actuation technologies embedded within the system to provide insight to the structure’s response and an opportunity to limit responses. The past thirty years have been characterized by a revolution in the field of smart structure technologies with sensors and actuators both reducing in size, power demands and unit costs. The efforts of this study have been chiefly focused upon two aspects of smart structure technologies: the development of a wireless monitoring system for structural health monitoring applications and decentralized structural control.

The benefits of installing a monitoring system in a structure are multiple, including opportunities to assess the health of the structural system over its expected lifespan. Historically, monitoring systems for civil structures are wire-based and employ hubspoke system architectures; unfortunately, their high installation and maintenance costs prevent them from becoming widely adopted. Using available technologies from the marketplace, a low cost alternative to traditional wire-based sensing systems has been developed. The unit’s key features include wireless communications, a 16-bit digital conversion of interfaced sensors, and a computational core that can perform various data interrogation techniques in near real-time. As a means of system validation, variou performance tests were performed including installation in the Alamosa Canyon Bridge, New Mexico.

Structural control systems can be used to limit the response of structures during external disturbances such as strong winds or large seismic events. As the trend of control devices progresses towards smaller and cheaper actuators, structural control systems will be characterized by large actuation densities. The resulting large-scale dynamic system is best controlled by decentralized control approaches. Various decentralized control techniques are considered including market-based control (MBC) and energy marketbased control (EMBC). Originating from the realm of econometric optimization, the structural system is modeled as a marketplace of buyers and sellers that leads to an optimal control solution. The approach, implemented in various analytical models, exhibits control performances comparable to the centralized linear quadratic regulation (LQR) controller. One distinct advantage of EMBC is its robustness qualities with respect to actuation failures in the control system.