Low Power Transmission Method Of Wireless Sensor Network Based On Beacon Network For Mechanical Vibration

The mechanical vibration wireless sensor network nodes are powered by a limited capacity battery,and have high performance requirements,such as high sampling rate,high precision synchronization algorithm,large amount of data transmission and so on,resulting in high energy consumption.the energy limitation of wireless sensor networks is more severe.Besides,the node state includes the acquisition state,the transmission state and the idle state,in which the energy consumption of the transmission state is the highest in the unit time.especially when a large number of mechanical vibration data are transmitted,the energy dissipation of the nodes is particularly significant.The existing mechanical vibration wireless sensor network nodes have the problems of excessive transmission energy consumption,so that it is difficult to realize long term mechanical vibration monitoring.There are many factors that affect the mechanical vibration wireless sensor network node transmission energy consumption,including the topology control,transmission power,sleep scheduling,transmission speed and data compression and so on.This dissertation focuses on the following three key factors that affect the transmission energy consumption of wireless sensor networks in mechanical vibration:(1)Aiming at the problems of machine vibration wireless sensor networks nodes are associated with the parent node according to the single criterion,make topology unbalanced in most cases and result in increasing transmission time and transmission energy consumption,a method of constructing a balance topology based on fuzzy analytic hierarchy process(FAHP)is proposed.,which consists of fuzzy judgment matrix and calculating the weight vector.Firstly,the nodes communicate with each other to get the beacon broadcast information,make network decision factors of beacon node unify dimension and construct fuzzy judgment matrix by using network decision factors.Then,check the consistency of fuzzy judgment matrix and the weight vector is calculated by normalization or Lagrange least square method.Finally,the comprehensive weights of each beacon node are calculated by the weight vector and choose the optimal beacon node as parent node to join the network.So as to build multihop balanced network topology,optimize data transmission path,improve data transmission delay and reduce energy consumption in idle time.(2)Aiming at the problems of machine vibration wireless sensor networks node with the most of the energy consumed by the wireless RF phase,resulting in a large transmission power consumption of sensor nodes,especially in mass raw data transmission requirements,a least squares adaptive transmission power control(LSATPC)method for wireless sensor networks nodes is proposed.Firstly,the discrete relationship between transmission power and link quality indicator(LQI)is studied through inner-cluster sensor nodes communication in the mechanical vibration monitoring in laboratory environment.Then,the least squares method is utilized to fit the discrete data,thus to construct the least squares adaptive transmission power mathematical model for reliable and energy-efficient data transmission.Finally,combined with the threshold value of LQI and transmission power range limitation of wireless communication module,the optimal wireless transmission power of the nodes at different communication conditions is calculated,satisfied with the result of the reliable data transmission.(3)Aiming at the problems of carrier sense multiple access with collision avoidance(CSMA-CA)in IEEE 802.15.4 under the mass raw data transmission requirement in mechanical vibration wireless sensor networks,such as multiple carrier sense cause high listening energy consumption and hidden node cause high retransmission energy consumption,a transmission-sleep timing scheduling method based on beacon synchronous trigger for machine vibration wireless sensor networks is proposed.Firstly,the feature of periodic whole network synchronization in beacon-enabled network is utilized to provide the basic time synchronization condition for distributed nodes,and design the super frame structure,ensuring the time consistent of each node receiving the scheduling information.Then,the feature of beacon can carry payload with network short address as scheduling information is utilized to broadcast the scheduling information with beacons,realizing the low overhead scheduling information notification mechanism.Finally,each node decides to whether transmit data or sleep according to the scheduling information,which significantly reduces the number of data collisions and idle currents in the process of data aggregation and optimizes unnecessary high transmission energy consumption defects for CSMA-CA during transmitting large amounts of raw data.(4)The wireless sensor network monitoring system with low power transmission is integrated for mechanical vibration.The data monitoring center software is designed based on C#.NET platform,in which the multi-hop networks management function and the node voltage monitoring function are realized.The performance of monitoring system is tested and the effectiveness of low power transmission method of wireless sensor network based on beacon network for mechanical vibration the proposed is verified by the experiment.At the end of the thesis,the summarization of the paper and prospects for the relative technology development.