Energy-Management for Power Aware Portable Sensor Systems

The design of power aware wireless sensor systems has gained increasing importance in recent research. Challenges in designing such devices are a throughout energy scalable design of hardware, signal processing and communication and an energy-effective energy management. The power supply should be capable to `harvest´ ambient energy and to accumulate superfluous energy in an energy storage unit in order to be able to bridge low energy availability. After an overview of the state-of-the-art in key technologies for power-aware portable sensor systems, we focus in this paper on energy management. An effective energy management plays a key role for energy-aware adaptation of system operation. An accurate up-to-date measurement of stored energy and remaining usable storage capacity allows to optimize operation and to extend maintenance-free periods. As challenging example we present recent results for the diagnosis of electrochemical batteries by impedance spectroscopy (Troltzsch, 2005)