Patent ID: 8462697
Filing Date: 2013-06-11
Classification: G01S,H04W

Abstract:
1. A sensor node having a self localization function, the sensor node comprising: a location information receiving unit to receive information about locations measured at each of two mobile nodes at different times; and a self localization unit to calculate a location of the sensor node by using four location information of the information received from the two mobile nodes, wherein the location calculating unit calculates the location of the sensor node by using a center of gravity of a virtual square formed based on four locations included in the location information received from the two mobile nodes and link quality indicators (LQIs) of packets transmitted from the two mobile nodes, wherein the location calculating unit comprises: a centroid operation unit to calculate the center of gravity of the virtual square formed based on the four locations included in the location information received from the two mobile nodes; a mobile node selecting unit to select a mobile node closer to the sensor node by using the LQIs of the packets transmitted from the two mobile nodes; a trajectory location calculating unit to calculate a predetermined point on a virtual line connecting two locations, which are included in location information transmitted from the selected mobile node, by using a LQI of the selected mobile node; a slope calculating unit to calculate a slope of the virtual line connecting the two locations; a shortest distance calculating unit to calculate a shortest distance between the virtual line and the center of gravity; and a location determination unit to select, as the location of the sensor node, a location which has been translated from the predetermined point in perpendicular to the virtual line by the shortest distance.