The Design Of Efficient Energy-Saving WSN Node Based On Dual-Energy

The rise of wireless sensor network (WSN) extends human capacity to interact with the real world, and it has wide applications in the aspects of military, anti-explosion, disaster relief, environment, and medical treatment. The working condition of WSN is usually severe, which human can’t often access, so the possibility of replacing energy restricted batteries is minimal. Once node battery runs out, which will influence on the surveillance quality and even lead to network paralysis. So, the problem of prolonging the service life of node needs to solved, especially ensure critical data reliable transmission.This paper introduced the classification of energy management technology in WSN. By analyzing the principle of energy management technology, it could be divided into two ways: developing and reducing expenditure. The study proposed two solutions from the developing way, which included the node power supply system based on dual-energy and battery scheduling algorithm of WSN node. First, the development of energy converter and rechargeable batteries was further analyzed. From the analysis results, a node power supply system was proposed, whose features were that it was consist of collection module based on the combination of solar and wind energy and energy storage module based on complementation of super capacitor and lithium batteries. Considering battery characteristics, rate capacity effect and recovery effect, a scheduling algorithm to decide which batteries have to work based on their remaining energy was presented. In order to reduce system complexity and delay with SOC circuit, the energy consumption model of node based on ZigBee protocol was proposed. These parameters, including working current, working voltage, time duration of data sending and receiving, etc, were used to establish energy consumption model of node. The purpose of WSN is to provide reliable data service. In order to ensure preferentially transmit of urgent data and balance energy consumption of each node in network, a priority MAC protocol was put forward based on IEEE 802.15.4. The data priority could be carry through changing frame format of IEEE 802.15.4 and the definition of node priority was confirmed based on intensity factor and load factor.Energy consumption model was tested based on JN5148 RF transceiver platform and the star network topology was adopted. The result shows that it can precisely predict the transmission energy consumption costs and the remaining life. Using the Kinetic Battery Model (KiBaM) and configuring relevant parameters can accurately express battery’s energy consumption curve. Based on the above work, MATLAB simulation results show that lifetime of node battery improves 75% compared with sequential scheduling and it is even 2% better than best-of-two scheduling, whose confidence level is 85 percent. Compared with the protocol of IEEE 802.15.4, the priority MAC protocol can improve network throughput, packet resending rate and packet average delay and ensure urgent data preferentially transmit.