For more information, visit the VTVT website.
Jina Kim demonstrates the size and function of an all-digital health monitor for structures.
The Virginia Tech VLSI for Telecommunications (VTVT) group has developed a prototype system to monitor the health of infrastructures, from buildings and railroads to spacecraft. The prototype, which is the first all-digital signal processing system, reduces power consumption by 80 percent of that of its predecessors and paves a way for a self-contained monitoring system.
“We want to be able to diagnose damage to infrastructures and verify the repair efficacy,” said ECE’s Dong Ha, director of the VTVT group. “The single most important aspect of developing a self-contained monitoring system is low-power dissipation. The system should operate on energy harvested from the ambient such as solar, thermal, or vibration. We need to squeeze out every drop to reduce the overall power dissipation ranging from DSP algorithms to the interface between a sensor and a digital signal processing chip.”
Ha explained that, in typical monitoring systems, sinusoidal tones are used to excite the structure, then the responses in the form of electrical impedance are measured and processed. His team, including graduate students Jina Kim (CPE) and Ben Grisso (ME), reduced power consumption by using digital pulse trains rather than sinusoidal tones and by observing only the polarity of the response signals. Using digital signals on both the structural excitation and the sensing allowed the team to eliminate both power-hungry digital-to-analog and analog-to-digital converters. It also simplified signal processing of the response signals, Ha said.
The interdisciplinary team from the VTVT lab and mechanical engineers from the Center for Intelligent Material Systems and Structures is supported by NSF on the effort. VTVT is part of the Center for Embedded Systems for Critical Applications (CESCA).
Computer engineering researchers, led by Michael Hsiao and Jung-Min Park are applying their verification, testing, and network security expertise to a system that can help protect the online privacy of children.
The system involves using a trusted third-party server, where parents register and allow different levels of access. The computer engineering team is developing the prototype and verifying that the overall system is secure, in order to protect children’s online privacy. They are working with researchers in the business college who are providing legal and focus group input and assessing the system with users.
The verification challenges in the system spring from the very large state spaces involved, said Hsiao. “One of the key steps is representation of the system during the state space traversal to avoid state space explosion.” The team is developing methods that are less vulnerable to memory explosion, such as automatic test pattern generation and satisfiability solvers.