Computer Aided Civil and Infrastructure Engineering

Structural health monitoring (SHM) using wireless sensor networks (WSNs) has gained research interest due to its ability to reduce the costs associated with the installation and maintenance of SHM systems. SHM systems have been used to monitor critical infrastructure such as bridges, high-rise buildings, and stadiums and has the potential to improve structure lifespan and improve public safety. The high data collection rate of WSNs for SHM pose unique network design challenges. This paper presents a comprehensive survey of SHM using WSNs outlining the algorithms used in damage detection and localization, outlining network design challenges, and future research directions. Solutions to network design problems such as scalability, time synchronization, sensor placement, and data processing are compared and discussed. This survey also provides an overview of testbeds and real-world deployments of WSNs for SH.

Structural Health Monitoring Using Wireless Sensor Networks: A Comprehensive Survey

This paper presents some of the oral discussion by the author and others at the 2005 Annual Meeting of the Los Angeles Tall Buildings Structural Design Council. It also includes additional opinions added by the author after the annual meeting. These opinions address the development of a new building code for tall buildings and where the non-structural engineering decision makers can and must make contributions. It also addresses the very important topic of quality control. Copyright © 2005 John Wiley & Sons, Ltd.

The structural design of tall and special buildings

Wireless Sensor Networks are considered to be among the most rapidly evolving technological domains thanks to the numerous benefits that their usage provides. As a result, from their first appearance until the present day, Wireless Sensor Networks have had a continuously growing range of applications. The purpose of this article is to provide an up-to-date presentation of both traditional and most recent applications of Wireless Sensor Networks and hopefully not only enable the comprehension of this scientific area but also facilitate the perception of novel applications. In order to achieve this goal, the main categories of applications of Wireless Sensor Networks are identified, and characteristic examples of them are studied. Their particular characteristics are explained, while their pros and cons are denoted. Next, a discussion on certain considerations that are related with each one of these specific categories takes place. Finally, concluding remarks are drawn.

Applications of Wireless Sensor Networks: An Up-to-Date Survey

The Internet of Medical Things (IoMT) designates the interconnection of communication-enabled medical-grade devices and their integration to wider-scale health networks in order to improve patients’ health. However, because of the critical nature of health-related systems, the IoMT still faces numerous challenges, more particularly in terms of reliability, safety, and security. In this paper, we present a comprehensive literature review of recent contributions focused on improving the IoMT through the use of formal methodologies provided by the cyber-physical systems community. We describe the practical application of the democratization of medical devices for both patients and health-care providers. We also identify unexplored research directions and potential trends to solve uncharted research problems.

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Internet of Medical Things: A Review of Recent Contributions Dealing With Cyber-Physical Systems in Medicine

The introduction of wireless telemetry into the design of monitoring and control systems has been shown to reduce
system costs while simplifying installations. To date, wireless nodes proposed for sensing and actuation in cyberphysical
systems have been designed using microcontrollers with one computational pipeline (i.e., single-core
microcontrollers). While concurrent code execution can be implemented on single-core microcontrollers,
concurrency is emulated by splitting the pipeline’s resources to support multiple threads of code execution. For
many applications, this approach to multi-threading is acceptable in terms of speed and function. However, some
applications such as feedback controls demand deterministic timing of code execution and maximum computational
throughput. For these applications, the adoption of multi-core processor architectures represents one effective
solution. Multi-core microcontrollers have multiple computational pipelines that can execute embedded code in
parallel and can be interrupted independent of one another. In this study, a new wireless platform named Martlet is
introduced with a dual-core microcontroller adopted in its design. The dual-core microcontroller design allows
Martlet to dedicate one core to standard wireless sensor operations while the other core is reserved for embedded
data processing and real-time feedback control law execution. Another distinct feature of Martlet is a standardized
hardware interface that allows specialized daughter boards (termed wing boards) to be interfaced to the Martlet
baseboard. This extensibility opens opportunity to encapsulate specialized sensing and actuation functions in a wing
board without altering the design of Martlet. In addition to describing the design of Martlet, a few example wings
are detailed, along with experiments showing the Martlet’s ability to monitor and control physical systems such as
wind turbines and buildings.

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Development of an extensible dual-core wireless sensing node for cyber-physical systems

This research studies a substructure finite element model updating approach that requires vibration data from only part of a large structure (i.e., a substructure). The residual structure is condensed using a limited number of dominant modal coordinates, whereas the substructure model remains at high resolution. To update the condensed model, physical parameters in the substructure and modal parameters of the residual structure are chosen as optimization variables; minimization of modal dynamic residuals from the eigenvalue equations in structural dynamics is chosen as the optimization objective. An iterative linearization procedure is adopted for efficiently solving the optimization problem. The proposed substructure model updating approach is validated with 1D, 2D, and 3D examples.

Substructure Stiffness and Mass Updating through Minimization of Modal Dynamic Residuals

The adoption of wireless sensing technology by the structural health monitoring community has shown advantages over traditional cable-based systems, such as convenient sensor installation and lower system cost in many applications. Recently, a new generation of wireless sensing platform, named Martlet, has been collaboratively developed by researchers at the University of Michigan, Georgia Tech, and Michigan Tech. Martlet adopts a Texas Instruments Piccolo microcontroller running up to 90 MHz clock frequency, which enables Martlet to support high-frequency data acquisition and high-speed onboard computation. The extensible design of the Martlet printed circuit boards allows convenient incorporation of various sensor boards. In order to obtain accurate acceleration data and meanwhile reduce the sensor cost, a new Martlet sensor board, named integrated accelerometer wing, is developed. The integrated accelerometer wing adopts a commercial-off-the-shelf MEMS (microelectromechanical systems) accelerometer and contains an onboard signal conditioner performing three basic functions, including mean shifting, anti-aliasing filtering and signal amplification. One distinct feature of the signal conditioner is the on-the-fly programmable cut-off frequency and amplification gain factor. To validate the performance of Martlet and the integrated accelerometer wing, experiments are carried out on a laboratory four-story aluminum shear-frame structure. The laboratory experiment results demonstrate that the performance of the wireless sensing system is comparable to that of cabled reference sensors. In addition, using data collected by wireless sensors, vibration modal properties of the structure are identified and finite element (FE) model updating is performed.© 2014 ASME

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Design and validation of acceleration measurement using the martlet wireless sensing system

We discuss the design, development, and deployment of an inexpensive, power-efficient, clustered, and scalable wireless sensor network (WSN) testbed. The testbed operates in a harsh environment in which neither GPS nor Internet connectivity are available. We use this testbed to collect real-time data during football games and other major events at Bobby Dodd stadium at Georgia Tech. The sensing devices in the testbed are synchronized without GPS or beacons, yet achieve sufficient accuracy to support modal analysis and detect if the stands are experiencing torsion. We have also developed a cognitive radio backhaul link to establish communication between the WSN in the stadium and a server in our lab. We present in detail the architecture, hardware components, and embedded software of the structural health monitoring platform. We also provide data collected during recent football games to verify the accuracy of the new synchronization algorithm and demonstrate that crowd behavior, such as rhythmic stomping, can be detected during a game.

Xinjun Dong

Papers

Development of an extensible dual-core wireless sensing node for cyber-physical systems

Substructure Stiffness and Mass Updating through Minimization of Modal Dynamic Residuals

Design and validation of acceleration measurement using the martlet wireless sensing system

A wireless sensor network for monitoring the structural health of a football stadium

High-Speed Heterogeneous Data Acquisition using Martlet-A Next-Generation Wireless Sensing Node