tailieunhanh - Programmable Logic Controller plant through MMI Part 7

Tham khảo tài liệu 'programmable logic controller plant through mmi part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 5 Holonic Robot Control for Job Shop Assembly by Dynamic Simulation Theodor Borangiu Silviu Raileanu Andrei Rosu and Mihai Parlea University Politehnica of Bucharest Romania 1. Introduction To be competitive manufacturing should adapt to changing conditions imposed by the market. The greater variety of products the possible large fluctuations in demand the shorter lifecycle of products expressed by a higher dynamics of new products and the increased customer expectations in terms of quality and delivery time are challenges that manufacturing companies have to deal with to remain competitive. Besides these market based challenges manufacturing firms also need to be constantly flexible adapt to newly developed processes and technologies and to rapidly changing environmental protection regulations support innovation and continuous development processes Nylund et al 2008 . Although the optimization of the production process remains a key aspect in the domain of fabrication systems adaptive production gains more and more field Sauer 2008 . Flexible manufacturing systems should be able to quickly adapt to new situations like machine breakdown machine recovery due to physical failure or stock depletion and also face rush orders Borangiu et al 2008 . In recent decades scientific developments in the field of production control have led to new architectures including heterarchical non-hierarchical architectures that play a prominent role in flexible manufacturing. The traditional approach is mainly associated to the initial CIM concept Computer Integrated Manufacturing and usually leads to centralized or hierarchical control structures in which a supervisor initiates all the activities and the subordinate units respond directly in order to perform them. Due to the complexity of manufacturing problems the usual practice has been to split the global problem into hierarchically dependent functions that operate within smaller time ranges such as planning scheduling control and .