New York may be the first state with a 24/7 wireless bridge monitoring system, reports EE Times. The $500,000 project is being funded by the New York State Energy and Research Development Authority. Engineering professor Kerop Janoyan at Clarkson University is working with TransTech Systems (Schenectady, N.Y.) to craft a commercial version of their wireless bridge monitoring system.
The wireless sensor nodes use accelerometers and strain gauges as well as more exotic sensors from ultra sound to eddy currents, depending on specific monitoring problems. Wireless nodes, which are battery powered, are polled by a master single-board computer that aggregates sensor data and determines whether to alert inspectors.
A test bridge between Canton and Potsdam, N.Y., has 40 channels of sensors with data logged in real-time from the wireless sensors at a basestation. By the end of 2007, Janoyan plans to have a wireless sensor network permanently installed on a New York state bridge.
“All of the weak points, especially inside a bridge’s load columns, can have sensors installed to assess their health,” said Janoyan. “If you install the sensors during new construction, then the cost is trivial compared to the cost of the massive steel and concrete beams and columns.”
Janoyan’s team has installed instruments on several New York bridges, including one under construction.
EE Times reviews some other solutions including “nanotube paint” that can turn any surface into a sensor patch that images microscopic faults in two dimensions. Los Alamos National Laboratory is using patchlike piezoelectric transducers to “ping and listen” for faults via a novel, unmanned-helicopter-based inspection system. Sandia National Laboratories is proposing a molecular-sized crack detector–at a cost of only $1 per sensor patch.
Physical Acoustics and Pure Technologies Ltd offer systems that can “hear” cracking in bridge cables or steel components so engineers can better assess the conditions of structures.
The Washington State D.O.T. uses both 4.9 GHz and 5.8 GHz (pdf) for their highway cams (right). IndigoVision’s video encoding systems deliver 1.5 Mbps of throughput for W-DOT, using MPEG-4 technology.
LifeSpan Technologies, which sells bridge-monitoring systems, has been extremely busy since Minnesota’s bridge collapse, said CEO Peter Vanderzee. But Tripp Shenton, an associate engineering professor at the University of Delaware, says states have moved slowly to adopt monitoring equipment because the extra expense has not yet been proven cost effective.
MicroStrain’s wireless, solar-powered sensor system can provide data on strain, seismic activity and vibrations on bridges, eliminating the need to manually replace batteries once the sensors are installed in hard-to-access places.
E-strategy has a terrific summary of the Minneapolis Bridge Collapse & Citizen Journalism.
DailyWireless has more on The Minneapolis Bridge Collapse.
