Patent ID: 7705286
Filing Date: 2010-04-27
Classification: A47B

Abstract:
1. A mobile storage system, comprising: a supporting surface; a plurality of storage units supported by the supporting surface, including at least a first storage unit that is movable toward and away from a second storage unit by operation of a drive arrangement to selectively create an aisle between the first and second storage units, wherein the aisle is accessible from at least one entry-exit area defined by end areas of the first and second storage units; and a sensing system for detecting the presence of persons or objects in the aisle and for detecting the direction of movement of persons or objects into or out of the aisle, wherein the sensing system includes a plurality of direction-sensing outer emitters and receivers located adjacent the entry-exit area of the aisle, wherein the direction-sensing outer emitters and receivers are spaced closely together at an exit zone in the entry-exit area of the aisle and throughout at least a predetermined distance extending inwardly from the entry-exit area of the aisle, and wherein the sensing system further includes a plurality of presence-sensing inner emitters and receivers located along at least an in-aisle area of the first and second storage units inwardly of the area of the aisle that is occupied by the direction-sensing outer emitters and receivers, wherein both the direction-sensing outer emitters and receivers and the presence-sensing inner emitters and receivers are positioned at an elevation below the storage units and above the supporting surface and are operable to detect the presence of persons or objects in the aisle and to detect the direction of movement of persons or objects into or out of the aisle without the use of sensors positioned at an elevation above the direction-sensing outer emitters and receivers and the presence-sensing inner emitters and receivers, wherein the sensing system further includes a logic system that detects the sequence of obstruction of at least the direction-sensing outer emitters and receivers to detect the direction of movement of a person or object into or out of the aisle at the entry-exit area of the aisle; wherein each exit zone of emitters and receivers comprises at least a pair of quadrature emitters and receivers at an endmost area of each of the storage units at the entry-exit area of the aisle, and wherein the exit zone further includes a plurality of the outer emitters and receivers located between the in-aisle area of each storage unit and the quadrature emitters and receivers, and wherein the inner emitters and receivers are each spaced a first distance apart in the in-aisle area of each of the first and second storage units, the outer emitters and receivers located between the in-aisle area of each storage unit and the quadrature emitters and receivers are each spaced apart a second distance less than the first distance, and the quadrature emitters and receivers are each spaced apart a third distance less than the second distance.