Fault-tolerant and maximally-permissive FMS controllers right out of the box—an automatic design approach

Abstract

Abstract This paper presents a comprehensive, all-in-one approach to automatic generation of high-level coordination controllers for flexible manufacturing systems (FMS). The approach comprises an intuitive graphical world wide web (WWW) user interface to specify the FMS layout and the desired production sequences. It also includes algorithms (a) to generate a proper Petri Net model for the specified plant, (b) to set up optimal (i.e. minimally restrictive) collision and deadlock avoidance policies together with a proper supervisory controller to enforce these policies, and (c) to react to disturbances such as machine breakdowns. These algorithms run in the design (offline) phase without user interaction. During online operation the operator only needs to indicate the arrival of new raw materials and the removal of finished products using the same user interface as mentioned before. An example implementation demonstrates the applicability and efficiency of the proposed approach.