Begin: Tue, 31. of Jan 2012 (12:30 PM)
Location: Warburger Str. 100, Room O3.267
On January 31, 2012, Christian Renner from the TU Hamburg-Harburg will give a talk about "Predictive Load Adaptation with Policies for Energy-Harvesting Sensor Nodes" in the context of the SFB 901 colloquium.
Abstract:
Energy-aware scheduling, also known as energy budgeting, is an evolving research area of energy-harvesting sensor networks. One essential aspect is to devise algorithms to dynamically determine the maximum supported uniform demand for energy of sensor nodes that are powered by energy harvesters and use supercapacitors as energy buffers. Knowledge about the maximum uniform consumption is required to adapt the sensor node's duty cycle or task schedule to achieve uniform, utility-maximizing and depletion-safe operation.
This talk covers a series of aspects on this topic and introduces a novel concept for load adaptation. Techniques for assessing a node's residual energy, predicting its potential energy harvest, and tracing its past energy consumption are presented for a prototype hardware and validated by an evaluation of real-world energy traces. Combining these techniques yields an energy-flow model that is exploited for predicting a node's future energetic course and deriving the maximum supported uniform load. In particular, the resulting algorithm makes use of a supercapacitors' relationship between state-of-charge and voltage, is designed to handle the non-linear system model, and is lightweight enough to run on low-power sensor node hardware. The algorithm is furthermore based on energy policies. In this talk, three practical energy policies are defined, their performance is evaluated, and the influence of the supercapacitor's capacity and errors of the energy forecast are analyzed.
