Research On Efficient Transmission Method Of Mechanical Vibration Wireless Sensor Network Based On IEEE 802.11 Protocol

Wireless sensor network has the characteristics of distributed,self-organizing,strong expansibility,convenient and flexible deployment.It can effectively make up for the shortcomings of traditional limited monitoring system in closed,large displacement,rotation and other special applications.It has great application prospects in the field of mechanical vibration monitoring.The weak mechanical vibration signal and wide frequency bandwidth require high-frequency and high-precision acquisition by nodes.This will generate a large number of vibration data in a short time,and there are a large number of deployed nodes in wireless sensor networks,which will inevitably bring great challenges to the network transmission channel.The traditional mechanical vibration wireless sensor network based on IEEE 802.15.4 protocol(ZigBee)has low transmission rate and narrow channel,which will lead to long transmission time and high energy consumption.The channel congestion caused by multi-node transmission will further increase the transmission energy consumption,which is not suitable for the monitoring of mechanical vibration wireless sensor network with limited node energy.For the problem of transmission energy consumption in mechanical vibration wireless sensor networks,this paper studies the low energy consumption and high efficiency transmission method based on the IEEE 802.11 protocol(WiFi).The main work is as follows:(1)To solve the problems of narrow wireless channel and low communication efficiency in mechanical vibration wireless sensor network nodes,a dual-core architecture node design method supporting IEEE 802.11 protocol is proposed,which provides co-hardware support for low energy consumption and high efficiency transmission of large amounts of data.Firstly,the coupling between acquisition task and network maintenance is reduced through the dual-core architecture design,and the dual-core cross-layer synchronization hardware design is carried out;secondly,the driver circuit of wireless module is designed to verify its low-power network maintenance performance;secondly,the energy consumption of nodes is reduced through multi-channel power management;secondly,the IEPE driver,filter and differential circuit of acquisition front-end is designed to enhance the signal.Finally,24 bits SAR ADC is used to ensure the acquisition accuracy and sampling frequency,and SD is used to store a large number of vibration data reliably.(2)Aiming at the problem that the synchronization and self-organization of the IEEE 802.11 protocol at home and abroad seldom consider the power consumption and size of the module,which is not suitable for the low-power miniaturized wireless module with fixed underlying protocol,a design method of protocol stack for mechanical vibration wireless sensor network based on the IEEE 802.11 protocol is proposed,which provides protocol stack support for the low-energy and high-efficiency transmission of large amounts of data.Firstly,the protocol stack architecture is designed;secondly,the functions of ad hoc network,acquisition control,data transmission and network node operation status reporting are developed;secondly,UDP broadcasting and hardware cross-layer method are used to optimize the trigger accuracy of multi-node acquisition;finally,the problem of high protocol power consumption is solved through low-power network maintenance design.(3)To solve the problems of multi-node and multi-link transmission,limited transmission efficiency and high energy consumption in mechanical vibration wireless sensor networks,a spatial parallel transmission scheduling method based on data block is proposed.Firstly,the reliability of Multistage link transmission is improved by link feedback and overtime retransmit mechanism;secondly,the problem of low efficiency of Multistage link communication is solved by using data block transmission method of Multistage link parallelism,and centralized rotation transmission timing scheduling method is used in multi-node transmission to reduce inter-node outbound interference;secondly,based on the transmission of different stages in transmission link.The method of multi-stage data block transmission and energy consumption optimization is designed to rationally divide the size of data packets,improve efficiency and reduce energy consumption.Finally,the Multistage link transmission,multi-stage block and multi-node scheduling are integrated and optimized to achieve multi-node spatial parallel scheduling,which can improve the transmission rate of Multistage link and multi-node scheduling efficiency,and make full use of high bandwidth.Advantages of communication networks.Finally,the paper summarizes the work of this paper,and prospects the future research direction.