Study on accurate positioning technology in underground mine based on non line of sight distinguishment

Acording to thelow postining acuracy of the moving objects n the underground mine and serious lintied problem by the non line of sight con.ition,the paper had a study on the features and technical limtations of the TOF and RSSl postioning ag orthms.The paper provided that tuo group ofomula of ratio of distance between the blid node and two anchor nodes could be obtained by using TOF and RSsl methods with the appication ofthe certai distance between the bolting nodes.According to the paramerers of the time difference and received signal strength ifference,the calcu ation ofthedistance measurement culd beindidualls condu.ted in order to improve the positioning accuracy The paper had study on the sestiyof the TOF and RSSl agrithms to the condtion ofthe non line of sight and obtaned tht the sensitity of SSl agorihm to non line ofsght condton was cbviously higher than that of TOF method,which coud be the basis for distinguishing the nonline of s ght condtion.Sinulaton and experiment have been conducted and results indicated tat the accurate positioning error could be less than five meters.