Energy aware self powered wireless sensor mote

摘要

Wireless sensor networks find applications including agriculture, transportation and automation. The wireless sensor mote and the network hardware subsystem play a vital role in sensing, monitoring and communication. In order to self-sustain the hardware infrastructure for the application, it needs to be self-powered, energy aware and efficient. This paper analyzes system design issues and options, architecture and performance of solar based sustainable self powered, energy aware and efficient wireless sensor motes that have been designed. Various power modules and schemes viz. Low Dropout Regulators, DC-DC converters, dynamic voltage and frequency scaling for their suitability and applicability to the wireless sensor mote design. DC-DC converter and battery management system for solar based energy harvesting have been adopted based on low quiescent current. DC-DC converter can start up from very low input voltages. Lithium-ion/ polymer battery has been used considering its high energy density and large cycle life. The battery management system comprising of battery protection, battery health-check by means of open circuit voltage measurement and fuel gauge provides required intelligence about energy density, power density and battery capacity availability to the system. The designed wireless sensor mote is scheduled to self-sustain without any change of batteries by converting the light energy into useful electrical energy and utilising the harvested energy efficiently.