Energy Management Technology And Theory Research On Wireless Sensor Networks

Sensor nodes of wireless sensor networks can be deployed with high density and large-scale due to its characteristics of low cost and self-organization,which make wireless sensor networks reflect subtle changes of environment and then enhance humman capability of acquiring and controlling information.So the application scenarios of wireless sensor networks are wide,such as military,industry,agriculture,transporation,family and environment protection,et al.However,there is great gap between the present technology level and the final destination,for example,low cost,low power and long work time of sensor node.The pratical utilization target needs performance improvement and theory breakthrough concerning wireless sensor networks.However,there is great gap between the present technology level and the final destination,for example,low cost,low power and long work time of sensor node.The pratical utilization target needs performance improvement and theory breakthrough concerning wireless sensor networks.Considering development direction of technology,this paper develops a novel wireless sensor networks demonstration platform based on 32-bit micro-controller and ZigBee.Energy management technologies adpoted in the development process are discussed.Energy balance theory issues of wireless sensor networks are researched based on stochastic optimization.Three kinds of sensor node with dynamic power management(DPM) ability are developed using 32-bit micro-controller LPC2138,low power consumption performance and energy management arthitecture of LPC2138 are analyzed.Through event-driven method,the interface design with other two sub-system of researched project is accomplished using sensor nodeâ…¢.The design satisfies evaluation index on continuous work time of project.A novel protocol stack based on ZigBee is developed.Un-slotted CSMA/CA is improved in order to avoid collision of acknowledge frame.Ad-hoc On-Demand Distance Vector(AODV) routing algorithm is simplified,which makes AODV energy efficient. According to mesh topology of wireless sensor networks,this paper puts forward self -calibration method to synchronize work state of sensor nodes,instructions sending delay are compensated using back-off mechanism.The minimal power consumption interference phenomena of sensor node are observed. Sum of components minimal power consumption does not equal to the whole sensor node miminal power consumption,pins configuration of LPC2138 affect power consumption of itselt and other components connected with LPC2138.It provides design guideline to decrease power consumption of sensor node.According to the condition that transmitting/receiving power consumption of sensor node nearly equal,this paper revises definition of charge unit defined by stochastic battery model,introduces waking-up meehanisim according to needs of sensor node,so that single pulsed stochastic battery model can be used to research energy balance issues of wireless sensor networks.Basic unit consisting one source node,several intermediate node and one destination node of wireless sensor networks is defined.Mathematical model used to balance energy consumption of basic unit and based on markov decision process is presented.The mathematical denotes system state through current battery nominal capacity,computes probability of state transition through battery recovery probability,choose decision criterion through recovery charge unit number being maximal.The results can be considered as reference to develop more efficient and optmal algorithm.