Abstract:

The emerging development of energy harvesting products has helped to reduce the cost of ownership of micro-power applications such as wireless sensor networks, providing potentially maintenance free-power sources, and can provide power to wireless nodes using energy present in the environment surrounding the application. Issues arise, however, with conventional energy storage devices such as batteries and capacitors, when they are required to provide reliable uninterrupted service to these applications for periods in excess of ten years. These issues include inherent high self-discharge rate and relatively short life spans, and prevent use of harvested energy to power consumer, industrial and civil applications. Additionally, the continued development of applications where energy harvesting is the primary power source in place of traditional battery or infrastructure energy sources is creating a demand for easily integrated, efficient "Plug and Play" modules that both store input energy and provide a regulated output for the target application electronics.

The combination of new thin-film Micro-Energy Cells (MEC TM) and efficient energy management electronics available from Infinite Power Solutions provides an energy storage solution that can last the lifetime of the target application, has the lowest energy loss, and the most efficient storage solution available using energy harvested from the environment surrounding the application. This new Micro Power Module (MPM TM) exploits a wide range of energy sources including solar, vibration, thermal and RF, directly accepting and storing inputs from energy harvesting devices and producing direct current through radio frequency energy, from 1 microwatt through 150 milliwatts continuously. An output regulator provides various regulated voltage options at continuous power levels exceeding 200 milliwatts.

Since many typical energy harvesting devices nominally produce energy at power levels below 100 microwatts, efficient gathering of that energy can be difficult using traditional regulation and conversion methods. The unique properties of the MEC that is in the MPM eliminate the need for regulation at typical EH power levels. Moreover, the low input energy threshold allows the MEC to efficiently accept power at levels as low as 1 microwatt and then store it for periods in excess of 10 years, ready for use on demand by the connected application via the integrated output regulator.

The MPM can be easily integrated or designed into existing or new applications without the need for external regulation or conditioning circuitry on either the EH inputs or at the regulated output. Options available include development tools, surface mountable versions, and reference designs available under license - all intended to provide rapid integration of energy harvesting into applications that need an autonomous energy supply.

 

1. Rail Cars and Wagons -WSN's and RTLS Bearings, Power Train, Cargo, Hazmat, Security, Location

2. Industrial WSN's for CBM

3. Remote wireless monitoring applications

 

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.