Research On Key Technologies Of Medium And High-speed Wireless Sensor Networks

A medium and high-speed wireless sensor network system generally consists of three components: sensor data acquisition nodes,central nodes and task management nodes.The purpose of the system is to sense,collect,transmit and process information from monitoring objects,generally used in industry and aerospace,etc.Compared with the traditional wireless sensor network,the medium and high-speed wireless sensor network requires higher data transmission rate and higher clock synchronization accuracy for better data comparison and analysis between sensor nodes.In this paper,the data transmission speed and clock synchronization accuracy of the medium and high-speed wireless sensor network are analyzed and studied from two aspects: multi-radio multi-channel technology and clock synchronization technology.In order to improve the data transmission rate of wireless sensing network,this paper investigates the multi-radio multi-channel technology from three aspects: topology,channel allocation and network communication.Firstly,based on the hardware characteristics of the central node carrying multiple RF modules,a two-level tree topology is designed,which has the advantages of being easy to build and having certain flexibility and reliability.A hybrid channel allocation algorithm is designed for channel allocation,which flexibly allocates channels to the four RF modules of the central node according to the network state and the number of available channels to avoid channel conflicts and crosstalk.Finally,the bearing capacity of the network is calculated,and the network formation process and node workflow are designed.In order to meet the clock synchronization accuracy requirements,this paper divides the clock synchronization into two phases,clock synchronization establishment and clock synchronization maintenance,when the clock synchronization algorithm is designed.In the clock synchronization establishment phase,a great likelihood estimation model is used to derive the communication delay and to compensate for the communication delay.In the clock synchronization maintenance phase,the least squares method is used to fit the relative clock frequency drift curve,and the clock is calibrated based on the fitting results;in addition,the algorithm also incorporates a clock self-correction mechanism,which effectively reduces the accumulation of clock errors in the sensor nodes.Finally,a hardware platform for medium-and high-speed wireless sensing network is built by selecting a domestic GD32F450ZKT6 main control chip and Si24R1 wireless communication module,and the algorithm designed in this paper is verified on the basis of this platform.The experimental results show that the algorithm based on multi-radio multi-channel technology increases the system data processing speed to 2 Mbps,which effectively increases the system data throughput.The clock synchronization algorithm maintains the synchronization error within 10μs,which provides the stability of the system operation.