Patent ID: 7504928
Filing Date: 2009-03-17
Classification: G08C

Abstract:
1. A method for determining a real-time location of an object within an indoor facility, the method comprising: obtaining a first plurality of sensor readings from a tag attached to the object, each of the first plurality of sensor readings transmitted from the tag at a first energy level; obtaining a second plurality of sensor readings from the tag attached to the object, each of the second plurality of sensor readings transmitted from the tag at a second energy level, the second energy level different from the first energy level; obtaining a third plurality of sensor readings from the tag attached to the object, each of the third plurality of sensor readings transmitted from the tag at a third energy level, the third energy level different from the second energy level and the first energy level; sorting each of the first, second and third sensor readings by a plurality of physical regions; selecting a first physical region of the plurality of physical regions for each of the first, second and third energy levels, the first physical region composed of a primary plurality of sensor readings having the highest average signal strength for each of the first, second and third energy levels; sorting the primary plurality of sensor readings into a secondary plurality of sensor readings for each of the first, second and third energy levels, each of the secondary plurality of sensor readings corresponding to a zone within the first physical region; selecting a selected zone having the highest average reading for each of the first, second and third energy levels; calculating a real-time location of the object from a plurality of the highest sensor readings from the secondary plurality of sensor readings corresponding to the selected zone for each of the first, second and third energy levels; and comparing each of the real-time locations for each of the first, second and third energy levels to determine a true real-time location of the object.