Fault-tolerant holonic manufacturing systems

This paper presents a model of fault-tolerant Holonic Manufacturing Systems (HMS), where each holon is a knowledge-based agent capable of solving distributed problems by applying production/assembly and information management services. Our multi-agent architecture provides robustness and distribution transparency within a shop-floor environment where unpredictable failures occur with machines, software, artifacts and communication networks. In the proposed framework, holons control an internal heterarchy of large-grain functional components where interaction among holons is carried out by user-defined cooperation strategies, enabling autonomous holons to coordinate their behavour. Therefore, holons can choose the most suitable dynamic rescheduling mechanism and component recovery mechanism in order to tolerate faults and keep the manufacturing system available. We also propose how the IEC Function Block Architecture for distributed control systems could be used as an implementation approach for our model. The model presented here is a crystalisation of the abstrcat concepts from Deen's cooperative distributed system [5], with suitable extensions to meet the criteria of both the ongoing HMS project and the constraints from the Function Block Architecture. The authors acknowledge that this research is supported in part by the European IMS Project 26508: Holonic Manufacturing Systems. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the HMS consortium or any other parties.