Patent ID: 7987050
Filing Date: 2011-07-26
Classification: B65G,B66F,G01B

Abstract:
1. A material handling vehicle location system in a warehouse in which a plurality of racks composed of upright frame members and lateral frame members connecting the upright members are installed so that a material handling vehicle can travel along a passageway between the racks; wherein a first reflector plate is attached to each of the upright frame members at a height position between adjacent lateral frame members or between the floor and is lowest lateral frame member so that the first reflector plates attached to the upright frame member face the passageway, and a plurality of second reflector plates are attached to the lateral frame member along longitudinal direction thereof; wherein a first sensor which emits a light beam and receives its reflection from each of the first reflector plates and a second sensor which emits a light beam and receives its reflection from each of the second reflector plates are attached to the vehicle; and wherein is controller which determine current location of the vehicle based on combination of the number of reflections actually received by the first sensor and counted by the controller and the number of reflections actually received by the second sensor and counted by the controller is installed on the vehicle.