Architecture for low volume AGV controlled FMS

Abstract

As computer integrated manufacture expands the search for lower cost and reliable machine communication links continues. In a typical Flexible Manufacturing System (FMS) there is a wide range of equipment available which may be used such as personal computers, Programmable logical controllers (PLC), CNC machines or robots. Each of these having their own "intelligence" and library of data. Providing a means of communication between a series of these individual controllers and the host controller has traditionally been achieved using a Local Area Network (LAN). The complexity of successful integration of each work station using a LAN results in a relatively high cost system. It is the objective of this project to devise an alternative to a LAN, in a flexible manufacturing cell, for communication of each station to the cells' controller. In the proposed solution an automatically guided vehicle (AGV) will be used as both the materials handling unit and the communications line, linking the work stations to the cell controller which will contain the scheduling algorithms for the materials within the cell.<br> Communication between the work stations to the host controller via the AGV, will be achieved by infra red data transmission eliminating hard wiring and network protocols. The AGV will operate in both download and upload mode. Downloading the necessary instructions with the machining file and uploading information the current status of the machine such as tooling or set-up constraints effecting material scheduling. The AGV acting as the host will have knowledge of the current status of the manufacturing cell as if it were connected to each work station by a LAN.<br> Scheduling of materials within the cell will also be performed by the AGV on board computer, being updated each time a work station is visited by the AGV which will in turn inform the host as to the condition of the cell.