A Wireless Modular Health Monitoring System for Civil Structures

Stanford University, Stanford CA

Investigators

Abstract

Summary: The objective of this research is to develop an integrated structural health monitoring system that utilizes advanced sensing, micro-processing, digital signal processing, wireless communication and damage diagnostic methods. The current project customizes and implements state-of-the-art miniaturized sensor units using MEMS technology and advanced wireless data communication methods that employ up-to-date components and architecture. A structure with such a distributed "smart" sensor network is thought of as a "Wireless IP Cloud of Sensors". New micro-accelerometers of high resolution are developed allowing for measurement of high amplitude vibration (i.e., earthquakes) as well as low amplitude vibrations (i.e., ambient vibrations) integrated with advanced wireless communication technologies and embedded systems for structural health monitoring applications. The research team is collaborating with Sandia National Laboratory in developing MEM-based accelerometers manufactured simultaneously along side CMOS circuitry on one die coupling the computation and sensor. The goal is to change the practices from extensive cabling and high cost labor, equipment and maintenance to the instrumentation of inexpensive wireless embedded systems. The proposed damage assessment algorithms are to perform (a) system level screening for quick identification of deterioration or damage; and (b) global diagnosis for structural performance and damage location identification. Statistical signal processing, energy dissipation and filtering methods are utilized that enable the computations to be performed locally at the sensor unit. A prototype system is to be tested both in the laboratory and the field. Significance and Broad Impact: The technology developed under this proposal will enable practical, cost-effective, long-term and quick response assessment of civil structures that estimates the degree of damage or degradation. The information provided by the system is critical following catastrophic events for reducing fatalities and for timely closure or continued operation of essential facilities (hospitals, fire stations, etc.). The system will also enable reliable systematic maintenance to prevent catastrophic failures under long-term deterioration.