خودسازماندهی در یک سیستم ساخت توزیع شده بر اساس منطق برنامه نویسی محدودیت

The paper addresses the problem of self-organization of manufacturing systems. The objective is to overcome the rigidity of conventional hierarchical structures and to introduce structures that are able to adapt to a dynamic environment. The presented approach is based on the concept of Complex Adaptive Manufacturing Systems. It is characterized by a decomposition of manufacturing objectives and allocation of tasks to work systems as autonomous building blocks in a dynamic environment. The allocation is based on a market mechanism that enables self-organization and optimization of a manufacturing system by evaluation and selection among competing work systems. The approach is implemented in the Constraint Logic Programming environment Eclipse and validated in a simulation experiment.

Rising complexity of products, production structures and processing procedures [ I ] on one side and turbulent market excitations resulting in growing product variety, individualization and shortening time frames on the other are setting new frontiers to the manufacturing business. Despite of research efforts and investments in the context of Computer Integrated Manufacturing the existing manufacturing systems are still predominantly based on the obsolete Taylorian philosophy. Therefore they cannot adequately conform to these requirements because of their structural rigidity, deterministic approach to decision making in a stochastic environment, hierarchical allocation of competencies, and insufficient communication and exploitation of expertise. In order to face new challenges in manufacturing a shift of the existent manufacturing paradigm from deterministic into a new manufacturing prospect considering natural understanding and concern is needed. Several influencing concepts in this direction have emerged in the last decade: Fractal Factory [2], Bionic Manufacturing Systems [3], Holonic Manufacturing Systems [4], and Distributed Manufacturing Systems (DMS) [5]. These concepts influenced research for more effective mastering of complex and dynamic behavior of the system and its environment, especially the Holonic and Distributed Manufacturing Systems concepts [6,7,8]. In the paper the results of further developments of the Distributed Manufacturing Systems concept are presented.

In the paper an approach to dynamic self-organized structuring of manufacturing systems is presented. It is based on the DMS architecture, which is an open structure, constituted by heterogeneous and redundant EWSs represented by VWS agents and connected in a network. The structuring process is governed by the market mechanism. The mechanism is based on coordination of activities among agents where mediators represent demand and virtual work systems represent supply - i.e. elementary work systems. Each agent optimizes its activities with the objective to maximize its performances with respect to current constraints. The result represents a dynamic manufacturing structure build-up for specific manufacturing objectives. Hence an impermanent manufacturing system for fabrication of a particular part is established. After the part is manufactured the temporal form of the manufacturing system vanishes. This task-machine allocation guarantees the optimal solution to the problem, rather than usage of fixed predetermined part sequencing rules.The approach is implemented in a prototype system developed in Eclipse. The system's shell consists of conventions of the DMS ontology expressed in form of rules and governs coordination control. For the optimization two modules are developed. The optimization is based on CLP, which is used because of its ability to master complex structures by constraints allowing declarative interpretation of basic relationships and rules. This system combines some good properties of hierarchical and heterarchical systems in terms of robustness and stability against disturbances and dynamic flexibility with respect to changes in the environment and therefore the equilibrium is continuously evolving with time.