Rapid development of a distributed shop floor control system from an XML model-based control software specification

Abstract

As the level of distribution in a shop floor grows, the development of a distributed Shop Floor Control System (SFCS) is of significant interest. Since hand-woven control software is expensive and difficult to reconfigure, a formal methodology that supports generating control software rapidly is in need of exploitation. Although a number of approaches on such purposes have been presented, they lack some of following characteristics: (1) ease of modelling a nature of a distributed SFCS, (2) rapid modelling capability, (3) integrity between specification and development methodologies, and (4) automatic software development capability. The objective of the paper is to propose a rapid development methodology that fulfils given characteristics through a formal model-based control software specification. Specifically, formal models, a resource model and an Monitoring-Decision making-Execution (M-D-E) model are proposed to specify Unit of Control Devices (UCDs) and their control processes performed in a distributed manner. The formal models are represented in the XML format to make them neutral to any model-building or development tools. In addition, the distributed SFCS control engine, a middleware for rapid development, is proposed to develop control software automatically from the XML-compliant formal models. As a result, the proposed set of formal models and control engine organizes the rapid development methodology most appropriate for a distributed SFCS.