Wind & Hurricane Impact Research Laboratory

Wind & Hurricane Impact Research Laboratory

(WHIRL)

Development of a Network of Wireless Instrumentation for Wind Monitoring

Description

This research has been funded by the Florida Sea Grant College Program, the Florida Department of Community Affairs, the National Science Foundation, and the National Research Council of Canada. It is concerned with the measurement & characterization of hurricane wind loads on structures using a wireless sensing networking system.

The 2004 hurricane season resulted in insured losses in excess of $20 billion. The 2005 hurricane season was even more catastrophic with Katrina identified as one of the costliest and most fatal natural disasters ever suffered by the U.S. Surveys of the structural damages caused by these hurricanes exposed the inadequacies in the existing building codes and practices. The existing codes (e.g. ASCE 7) are developed based on wind tunnel testing of model scale structures in open exposure, including some correction factors for full-scale effects. However, more accurate statistical models that would include the effects of varying exposure require extensive and reliable measurement of wind fields and pressures on different full-scale buildings. The current field measurement technologies for hurricane environments are subject to data loss and reliability issues, rapid deployment problems, and lack the means for “real-time” rectification of any system breakdowns during data collection. This research resulted in the design and building of a network of wireless sensor systems to reliably measure the hurricane wind loads on residential structures. An extensive test bed (structures ready to receive the instrumentation) already exists, providing the researchers access to over 30 structures along the Florida coast on which to employ the sensor network. The resulting full-scale datasets will be used to establish relationships between actual full-scale loads and the wind tunnel datasets used to create load provisions.

One of the innovative parts of the research was to create an integrated reliable system for multi-point sensing in harsh environment by combining cutting edge local and global wireless networking and modern low power electro-mechanical sensors technologies. The system comprises a cluster of mobile nodes (sensors) distributed over the roof top and walls of a residential or commercial building, or essential infrastructure, and a centrally located, environmentally protected master node (base unit) to monitor the operation of the mobile nodes and act as a data repository. The master node communicates in real time with a central command located away from the landfall area, for remote management, monitoring, and data transmission. The second innovative part of the research is the creation of an object oriented and adaptive data acquisition algorithm. For example, the data collection is active only during the periods of intense winds, or, the sampling rate are tuned according to the frequency of intense events. The whole system performance was assessed in simulated laboratory and actual field environments. Finally, availability of the high quality measurements from the wireless sensor networks will provide the researchers with means of evaluating existing wind structure interaction models and wind tunnel studies and to create models that are more sophisticated and more accurate than the ones that exist today in the building code.

Funding

2009-2010 Mitigation of hurricane damage on residential structures: direct measurement and characterization of hurricane wind loads on residential structures using a wireless sensor networking system. Funded by the Florida Department of Community Affairs.
2009 Pilot Study of Wireless Technology for Monitoring of Membrane Roofs. Funded by the National Research Council of Canada.
2008 Instrumentation of Deerfield House. Funded by the Hurricane Warning, the Disaster Survival House.
2006-2009 Measurement & Characterization of Hurricane Wind Loads on Structures Using a Wireless Sensing Networking System. Funded by the National Science Foundation.
2006 Adapting Wireless Technology for the Wall of Wind: A Pilot Study. Funded by the Florida Department of Community Affairs, through the International Hurricane Research Center at FIU.
2002-2004 Hurricane Wind Gust Structures: Measurement, Characterization and Coastal Damage Mitigation. Funded by the Florida Sea Grant College Program. Joint proposal with the University of Florida.
2000-2001 Development of Advanced Instrumentation for Monitoring of Wind Action on Coastal Structures – Funded by the Florida Sea Grant College Program.

Theses

Wireless pressure Monitoring System, by Claudio Daniel Lapilli

Abstract: Due to the increasing urbanization in the coastal areas of the United States, there are more and more structures subjected to the threat of hurricanes and high-speed windstorms. The current structural design guidelines are mostly based in wind tunnel experiments, and the general consensus is that more full scale studies are needed to fully understand the behavior of structures subjected to hurricane strength winds. A non intrusive pressure monitoring system was developed by Clemson University to measure wind induced pressure on low-rise structures. The system requires a significant number of wires installed on each building to transmit the information from the sensors on the roof to a data collector installed in a box outside the building.

To overcome the difficulties of installation, a wireless pressure monitoring system was developed and tested. The final system can work with up to 60 pressure sensors. The sampling rate can be selected from 0.125 Hz up to 100 Hz, with a total data transfer rate in the system of 700 samples per second. The wireless system uses a proprietary communication protocol completely developed as part of this project. Buffering technique and an adaptive queuing algorithm were used to improve the system fault-tolerance.

A complete prototype system was built consisting in one base unit, 23 pressure sensing remote units and one anemometer remote unit. Data collection software was developed as an integral part of the system, and a post processing program was also written as a companion. An extensive set of validation tests were carried out to assess the system's ability to replace the existing hardwired system.

Wireless networked data sensors for hurricane monitoring by Antonio Velazquez Hernandez

Abstract: In the past several years a team of researchers from the University of Florida and Clemson University, and more recently Florida Institute of Technology, have collected full-scale wind measurements of the turbulent ground-level wind field and the resultant pressures on low-rise structures. One result of this effort is a wireless data acquisition system developed and tested at the Florida Institute of Technology. This system has included the development of two current sets of 30 wireless sensors, and a new third generation that is in progress that will measure pressures, temperature, reception-strength signal and battery charge, as well as adapted wireless anemometers to reproduce synchronized wind speeds, and wind direction. The data is collected and stored in a portable computer powered by a long-duration battery console. This portable design offers the advantages of less and smaller pieces of hardware, ease of installation, capacity for more than 48 hours of continuous data acquisition, good frequency and amplitude responses, and relatively easier maintenance. All these appointments serve as a motivation to embrace the construction of a made-home self-sufficient data acquisition system called WINDS-HM (WIreless Networked Data Sensors for Hurricane Monitoring). The steps in during the development of such a tool will include the analysis, design, construction, test, implementation and implantation, data analysis and deployment. Several capabilities beyond the singular acquisition of data have been promoted and implemented to produce a set of smart sensors with diversified capabilities to generate data, data filter, diagnose, configure remotely, troubleshooting, pattern recognition, down sampling, adaptive calibration, among others. The idea behind the scene is to generate in different environment conditions, ability troubleshoot remote devices anywhere, software components to better illustrate the data acquisition process, and to facilitate testing in laboratory and field deployment. The last chapter of this documents a data verification of the outcomes and overall performance.

Performance Testing of the Wireless Sensor Network System for Hurricane Monitoring, by Frédéric François Kreit

Abstract: A wireless pressure monitoring system was developed by Florida Institute of Technology to measure wind induced pressure on low-rise structures during hurricanes. Previous deployments did not perform as desired. To ensure that the system was operational and capable of providing accurate measurements, a reliability study had to be performed.

The first part of the reliability study tested the system’s performance in several tests. From this study, a series of protocols and procedures were created to simplify the maintenance of the system.

A post-processing software was developed to rearrange the data, establish a performance analysis of each remote, resample the recorded measurements, and plot the results.

To test the reliability of the pressure sensors, a series of tests were designed. The resulting measurements were then compared to reliable references. The measurements were also compared to the basic Bernoulli theory by using the wind tunnel at the Florida Tech Fluids Lab. This allowed for the development of the first comparative CFD simulation, and the simulation results were then compared to the experimental results.

Finally, due to the material contained in the sensors, the sensor case cannot be completely flat. The resulting shape creates aerodynamic disturbances. In order to study the sensor shape’s influence on the pressure measurements, different experiments were set up. Specifically, by using a roof model mounted on a van, a highway test was performed, allowing examination of the error caused by the sensor’s shape. Another test was performed at the University of Florida using the Hurricane Simulator to show the influence of a row of sensors on the following rows.

Hurricane Wind Effects: Instrumentation, Measurement and Analysis by Gabriel Danilo Lapilli

Abstract: In the past years, hurricane wind effects have been a topic of extensive studies. Building damage caused by tropical cyclones needs to be minimized for both economic and societal reasons. The cost associated with certain damage is not only quantified in terms of how much money was spent in the repairs and the inactive time, but also by the harm it caused to a community as a whole, including the psychological burden for those who have perished. On the other hand, the construction cost needs to be kept low to allow families to easily rebuild their own homes, creating a critical need for the engineering community to design better, more reliable and structurally efficient houses.

Towards this goal, in the present Thesis, an advanced wireless pressure sensors system is developed with the purpose of measuring pressures on the roofs of houses during natural hurricanes to quantify wind loads on full-scale residential building roofs. The working principles of this system are explained to detail, a full insight on its proper employment is given, and hurricane wind meteorological characteristics are addressed. The system is able to reliably collect pressure data at a sample rate of over 30 samples per second in a full network. Its precision falls well below 10% of the pressure differences willing to be measured, in the range of 0.6 mbar. The pressure transducers are thermally stable for the operating range, meaning no need for temperature correction of the measurements.

Since no pressure data was collected due to the lack of tropical activity over Florida, pressure analyses on roofs were not possible. However, in order to understand the interaction between an object (in this case, a low-rise building) and the free flow, it is first necessary to define the free flow properly. For that, a new perspective is proposed for analyzing data collected within the lower layers of the boundary layer of storms. Since pressure and velocity are directly related, these methods are developed using real velocity storm data from several towers, collected by the Florida Coastal Monitoring Program. The mean and fluctuating velocities are separated and defined using variable time averaging, and a directional exposure coefficient is proposed to address the fluctuating velocity characteristics. 

Publications

Journals

2013 C. S. Subramanian, J.-P. Pinelli, I. Kostanic, G. Lapilli, “Analysis and Characterization of Hurricane Winds,” ASCE Journal of Engineering Mechanics, March 2013, 1-14.
2012 Chelakara Subramanian, Jean-Paul Pinelli, Ivica Kostanic, Gabriel Lapilli, “Design, Development and Testing of a Wireless Multi-sensors Network System,” Journal of Mechanics Engineering and Automation, David Publishing Co., Inc., Libertyville, IL, 2 (2012), 169-183.
2011 Subramanian, C. S., Lapilli, G., Kreit, F., Pinelli, J.-P, Kostanic, I., “Experimental and Computational Performance Analysis of a Multi-Sensor Wireless Network System for Hurricane Monitoring”, Sensors & Transducers Journal, Vol.10, February 2011, pp. 206-244.
2009 Otero, C., Velazquez, A., Kostanic, I. Subramanian, C., and Pinelli, J.-P., “Real-Time Monitoring of Hurricane Winds using Wireless Sensor Technology,” Journal of Computers, Vol.4, No.12, pp. 1275-1285, Dec. 2009.
2005 Pinelli, J.-P, Subramanian, C. S., Lapilli, C., Buist, L., “Application of a Wireless Pressure Sensing System to Coastal Wind Monitoring,” Wind and Structures Journal, Vol. 8, No. 3 (2005), pp 179-196.
2005 Subramanian, C. S., Pinelli, J.-P., Lapilli, C., Buist, L., “A Wireless Multi-point Pressure Sensing System: Design and Operation”, IEE Sensors Journal, Vol.5, No.5, October 2005, pp 1068-1074.

Conference Proceedings

2012 Subramanian, C., Jean-Paul Pinelli, Ivica Kostanic, Gabriel Lapilli Wireless, “Multi-Sensor Network System,” Proceedings, Advances in Hurricane Engineering, October 24-26, Miami, FL.
2011 Chelakara Subramanian, Jean-Paul Pinelli, Ivica Kostanic, Gabriel Lapilli, « Engineering Mechanics Institute Conference (EMI2011),” Engineering Mechanics Institute Conference (EMI2011), June 2-4, Boston, MA.
2011 C. Subramanian, Jean-Paul Pinelli, Ivica Kostanic, Gabriel Lapilli, Jiten Chandiramani, ”Wireless sensors for measuring wind-borne pressures during hurricanes,” Proceedings, International Symposium on Nondestructive Testing of Materials and Structures, Istanbul, Turkey, May 15-18, 2011.
2011 J.-P. Pinelli, C. Subramanian , I. Kostanic , G. Lapilli , “ Direct measurement and characterization of hurricane wind loads on residential structures using a wireless sensor networking system,” Proceedings, 5th International Symposium on Wind Effects on Buildings and Urban Environment, Tokyo, March 7-8, 2011.
2010 Lapilli, G., Chandiramani, J., Kostanic, I., Pinelli, J.-P., Subramanian, C., and Poske, C., “New Wireless Sensors System for Pressure Measurement,” Proceedings, 2nd AAWE Workshop, Marco Island, FL, August 18-19.
2010 Frederic Kreit, Guillaume Barberio, Chelakara Subramanian, Ivica Kostanic, Jean Paul Pinelli, “Performance Testing of the Wireless Sensor Network System for Hurricane Monitoring,” Proceedings, The First International Conference on Sensor Device Technologies and Applications, Sensor devices 2010 Conference, Venice, Mestre, Italy, July 18 – 25, 2010.
2009 C. S., Subramanian, Jean-Paul Pinelli, Ivica Kostanic, Larry Buist, Bartel Van der Veek, Antonio Velazquez, Frederic Kreit, and Carlos Otero, “Development and testing of a second generation wireless hurricane wind and pressure monitoring system,” Proceedings, 11th Americas Conference on Wind Engineering, San Juan, Puerto Rico, June 22-25, 2009.
2008 Ivica Kostanic, Chelakara Subramanian, Jean-Paul Pinelli, Larry Buist, Antonio Velazquez, and Adam Wittfeldt, “Monitoring of Hurricane Wind Pressures and Wind Speeds on a Residential Home Roof with Wireless Instrumentation,” Proceedings, ASCE 2008 Structures Congress, April 24-26, 2008, Vancouver, Canada.
2007 Jean-Paul Pinelli, Chelakara Subramanian, Kurt Gurley, and Shahid Hamid « Validation of the Florida Public Hurricane Loss Projection Model,” Proceedings, 12th International Conference in Wind Engineering, Cairns, Australia, July 1-6, 2007.
2005 Pinelli, J.-P, Subramanian, C. S., Lapilli, C., Buist, L., “Development of a Wireless Pressure Sensing System for Coastal Wind Monitoring,” Proceedings, 4th European and African Conference on Wind Engineering, Prague, July 11-15, 2005.
2005 Subramanian, C. S., Pinelli, J.-P, Lapilli, C., “Deployment of a Wireless Wind Pressure Sensing System during the 2004 Hurricane Season,” Proceedings, 10th Americas Conference on Wind Engineering, Baton Rouge, Louisiana, May 31- June 4, 2005.
2005 Subramanian, C. S., Pinelli, J.-P., Lapilli, C., Buist, L., “A Remote Multi-Point Pressure Sensing System,” 43rd AIAA Aerospace Sciences Meeting, Reno, Nevada, paper # AIAA 2005-274, pp 1-15, January 10-13 2005.
2001 Subramanian, C. S., Pinelli, J.-P., L. Buist, T. Reinhold, “A Wireless Data Acquisition System for Coastal Wind Monitoring,” Proceedings, Americas Conference on Wind Engineering, Clemson, June 2001.
2001 Pinelli, J.-P., Subramanian, C. S., T. Prem Kumar, T. Reinhold, K Gurley, “A Data Visualization and Analysis Program for an Instrumented Coastal House,” Proceedings, Americas Conference on Wind Engineering, Clemson, June 2001.

WindPlot Software Download

WindPlot Software Download—WindPlot is a data processing and visualization software developed entirely in MATLAB for plotting wind pressure distribution over a roof and the associated wind speed and direction. The user can select a plot of his choice from various menus on the screen. All the menus and the commands are explained below in detail.

The complete source code & the documentation is available in different formats.

The directory structure is as follows.

  • Create 2 directories plot & data in the same directory.
  • Inside the plot directory , unzip the Code
  • Place the house.inf file in the data directory.
  • Inside the data directory, create another directory called text & unzip the text data into it.
  • From MatLab go to the plot directory & run the windplot.m file.

Documentation: PDF | Word

Code: Zip - File

Text Data: Zip File

House Information: House.inf