Research On Optimization Of Collaborative Positioning In Monitoring Underground Pipeline Gallery

With the development of the underground pipe rack,the integrated monitoring of the underground pipe rack environment has became the top priority in the management of pipe rack.And effective fast accurate positioning of the accident,has been a research hotspot.Underground pipe rack,which is complex and changeable,is a semi-enclosed narrow space.Due to the emergence of non-line-of-sight situation,the sensor node positioning is very difficult,and the accuracy is not good.In view of the special situation of the underground pipe rack,like the multipath interference,research on the more effective localization algorithm is the focus of this paper.Based on the research of the relevant localization algorithm,this paper discusses the localization algorithms based on RSSI and AOA,and then introduces the idea of combining RSSI and AOA algorithm to improve the accuracy of the algorithm,and proposes the least squares non-convex estimation(LSNCE)algorithm.The algorithm is divided into two processes:the first step is,through the received signal strength information(RSSI)and the angle of arrival information(AOA)of the unknown node,to obtain the position estimation of the unknown node by using the least squares method.And for the second step,we first introduce an auxiliary variable X and an auxiliary vector z of the unknown node.By applying the semidefinite programming relaxation technique,the position estimation is transformed into convexity,and we also obtained en Epigraph variable.Then,the optimal solution of the position estimation is obtained by using the CVX toolbox(included in MATLAB),That is,the final location of the unknown node.The theoretical analysis shows that within the multi-path interference scene,the least squares nonconvex estimation algorithm has higher accuracy than the previous algorithm.Contrast to the selected hybrid weighted algorithm and the second weighted least squares algorithm,simulation analysis under simulated conditions of underground pipe rack,results show that the least squares non-convex estimation(LSNCE)algorithm can effectively improve the positioning accuracy,at the same time shows the good anti-jamming ability.