Research On ZigBee-Based Subway Station Constrution Personnal Positioning Algorithm

Subway construction project is a complex and dangerous project.There will be various uncertain factors in the project,which will lead to potential safety hazards for construction personnel.Moreover,the general construction environment is located underground,and the internal network structure of the sensor needs to be changed due to the different construction terrain and space,resulting in poor accuracy and adaptability of personnel positioning monitoring.Aiming at this problem,various wireless sensor network technologies are studied.Combined with the subway construction environment,ZigBee is selected as the hardware scheme of this subject.The classical positioning algorithm is studied in depth and it is found that the weighted centroid positioning algorithm is more in line with the subway construction environment.However,in the simulation experiment,it is found that there is still some room for improvement in the accuracy of the algorithm.The size of its initial weight has a great influence on the positioning performance,and when the number of anchor nodes changes,the initial optimal weight coefficient will also change.In this paper,two improved methods are proposed for the defects of the algorithm,which can effectively improve the positioning accuracy and adapt to different initial weights,and improve the adaptability to different number of anchor nodes,as follows :(1)The weighted centroid localization algorithm based on Euclidean algorithm is improved.On this basis,the vulnerability that when two anchor nodes are taken as the center of the circle,the distance value converted by the received RSSI value is drawn as the radius,and the two circles cannot intersect is corrected.The weight value is the reciprocal of the product of the radius,so that the anchor node close to the unknown node aggravates its influence and weakens the influence of the anchor node far away from the unknown node.The simulation results show that the improved method has a certain improvement on the accuracy of the algorithm.(2)Feature analysis of weight coefficient of weighted centroid algorithm.The improved weighted centroid algorithm formula is derived,and the specific influence of the weight coefficient adjustment range of each anchor node on the unknown node is obtained and verified by simulation.It provides feasibility for further improving the positioning algorithm.(3)An adaptive weighted centroid localization algorithm based on Euclidean algorithm is proposed for the characteristics of weight coefficients.According to the principle of negative feedback control,the algorithm reduces the positioning error by adjusting the initial weight coefficient of the algorithm based on the improved weighted centroid localization algorithm based on Euclidean algorithm.The simulation results show that the improved method is more accurate than the traditional weighted centroid method and the Euclideanbased weighted centroid localization method,and it is basically not affected by the initial weight coefficient,that is,it is basically not affected by the number of anchor nodes.(4)Through the ZigBee hardware platform,in the subway construction environment simulated by the basement,the above simulation is verified one by one.The improved algorithm not only improves the accuracy,but also the initial weight coefficient and the number of anchor nodes have little effect on the accuracy of the improved algorithm.