Plural number control system for an automatic warehouse

Claim 1

A warehousing system comprising: a plurality of load storing means; an article conveyor, load handling means mounted on said coNveyor to remove or deposit a load from a selected one of said load storing means; drive means for moving said article conveyor in a travel zone adjacent said load storing means; a plurality of location means disposed in relation to said load storing means and each embodying a BCD system having an arrangement of groups of binary digits in BCD form with each group representing a different decimal power of ten for identifying a location along said travel zone effectively related to a load storing means; sensing means mounted on said article conveyor for reading the BCD binary digits embodied in each location means; control means for said drive means including address means for receiving an arrangement of binary digits in BCD or pure binary form and representing a number identifying a selected load storing means, pure binary subtractor means having a first input coupled to said sensing means and a second input coupled to said address means for effecting between the pair of BCD binary digits at said inputs subtraction in a pure binary system having an arrangement of binary digits in continuous sequence representing successive powers of two, said subtractor means includes a plurality of difference means for generating at least difference bits D1, D2, D4, D8, D10, D20, D40 and a plurality of borrow means for generating at least borrow bits B1, B2, B4, B8, B10, B20, B40 resulting from pure binary subtraction of the pair of BCD binary digits at said inputs; and detector means responsive to the pure binary subtraction of said subtractor means for modifying the speed of said article conveyor whenever said article conveyor is a preselected number away from said selected load storing means, said detector means determining when said article conveyor is a preselected different X away from said selected load storing means by solving the Boolean equation X B40 D40 D20 D10 D8 (B8 + D4 D2 D1) + B40 D40 D20 D10 D8 (B8 D1 + D4 D2 D1) or by solving the Boolean equation X B40 D40 D20 D10 D8 (B8 D4 D2 D1 + D4 D2 D1) + B40 D40 D20 D10 D8 (B8 D8 D1 + D4 D2 D1).