Research On Adaptive Control Of Network Transmission Power In Seismic Exploration Wireless Acquisition System

The development of seismic exploration acquisition system based on large-scale self-organizing wireless sensor network is an important research direction.In the application research,the power consumption control of sensor nodes is considered as a difficult problem.In this thesis,the network transmission power adaptive control in seismic exploration acquisition system is taken as the research topic,and the research is carried out in three aspects:wireless transmission network design,sensor node ranging algorithm and power adaptive control algorithm.According to the characteristic that the data in seismic exploration is gathered from the acquisition nodes to the acquisition center station,which lead to the fact that the closer to the acquisition center station,the greater the amount of data to be transmitted.In this thesis,a low power cluster heterogeneous network design combined with high and low transmission rate is proposed.Based on the adopted protocol,the transmission network is divided into low-power,low-rate intra-cluster subnets composed of the ZigBee protocol based on the IEEE 802.15.4 standard,and high-speed,high-real-time trunk networks composed of WiFi protocol based on the IEEE 802.11b/g/n standard.The network design not only meets the low power consumption and low-cost requirements of the acquisition node,but also improves the network load capacity near the acquisition center stationThe distance information between sensor nodes plays an important role in the implementation of network transmission power adaptive control algorithm.For the hardware conditions,a node ranging algorithm combines RSSI data and LQI data is proposed.The attenuation stability numerical interval of RSSI value and LQI value is determined by offset degree,and different weights are given according to the magnitude of the numerical offset degree in each interval.Then,the weight matrix is processed by two-dimensional sliding average method.Finally,the empirical model of ranging algorithm obtained by least squares fitting has higher ranging accuracy and stronger anti-interference abilityMost of energy consumption in wireless communication system is concentrated in the process of transmitting and receiving signals.Adaptive control of transmission power can reduce invalid energy consumption,cut redundant communication links,and optimize the overall performance of the network.According to the characteristics of the network design in seismic exploration wireless acquisition system,and taking into account the system hardware cost and the computing ability of the acquisition node,a power control algorithm based on K-NEIGH and COMPOW is proposed in this thesis.Firstly,the transmission power level is determined by selecting the appropriate value of K.Then,the minimum transmission power is unified in the neighbor set,and the unidirectional links in the neighbor set are corrected.Finally,the request-response mechanism is adopted to ensure that there are no isolated nodes and isolated subnets in the network.Through simulation and analysis,the ranging algorithm and power control algorithm proposed in this thesis are compared with the existing methods,and the network test is carried out in the actual environment to verify the rationality of the designed wireless transmission network,and the effectiveness and reliability of the proposed sensor node ranging algorithm and the adaptive control algorithm of network transmission power are also demonstrated.