Synchronized Energy Harvesting Wireless Sensors for Structural Health Monitoring (Energy Harvesting & Storage USA 2009)

 

This presentation reports on a versatile, fully programmable wireless structural health monitoring system, designed to synchronize and record data from a range of wireless sensors, including strain gauges, accelerometers, force, pressure, and torque cells. Data were collected at multiple sampling rates, time stamped, and aggregated within a single scalable database on a base station, termed the wireless sensor data aggregator (WSDA). The WSDA also provided a beacon to synchronize each sensor node's embedded precision timekeeper. High speed wireless sensor nodes were demonstrated to be capable of data logging in bursts (50 K samples/second, 1 second duration, once a minute) while consuming only 16 mW. In this mode, high sample rate nodes can operate perpetually, without batteries, by using miniature vibration energy harvesters, which provided 37 milliwatts of continuous DC power under conditions replicating a helicopter gearbox. Wireless node network initial synchronization in response to a centrally broadcast network command, such as to initiate node sampling, or to synchronize node time keepers, was measured at +/- 4 microseconds. With the time synchronization beacon sent only at the onset of a two hour long test run at temperatures of -40 to +85 deg C, the system's timing accuracy was ~5 milliseconds. The system is capable of remote reporting using mobile phone networks, with satellite communications under development. These capabilities enable critical structural sensor data to be managed remotely and automatically without the need for battery maintenance.

Mr. Arms received his Master's Degree in Mechanical Engineering at the University of Vermont in 1983. He has been awarded 30 US patents, and has over 10 pending. He has contributed to 18 journal publications and 44 abstracts/presentations in the areas of advanced instrumentation, wireless sensing, and energy harvesting. Mr. Arms is founder & CEO of MicroStrain, Inc., a leading manufacturer of displacement , orientation, and wireless sensor systems for remote monitoring of advanced machines and structures.

Founded in Williston, Vermont, 1987, MicroStrain is a privately held corporation producing innovative wireless, micro-miniature displacement, orientation and strain sensor networks for the next generation of smart machines and structures. Our patented wireless sensing systems combine advanced, time-synchronized micro-power electronics with miniaturized vibration, strain, and solar energy harvesters. These systems are reliable, easy to install, and eliminate costly wiring and battery replacement.