Hierarchical Management and Control in Manufacturing Systems
- Project Title:
- Hierarchical Management and Control in Manufacturing Systems
- Work Area:
- Theories and models for the design of heterogenous systems
- EICAS Automazione S.p.A.
Via Vela 27
I- 10128 TORINO
- Coordinator Country:
- Universität Karlsruhe D
INRIA Lorraine F
Technical University of Crete GR
- Contact Point:
- Prof. M. Vallauri
- +39/11 5623798
- +39/11 4360679
- hierarchical control systems, factory, dynamics, process modelling, production planning & scheduling, information technology, mass production, one-of-a-kind production
- Start Date:
- to be announced
- HIMAC aims at developing mathematical theories and methodologies for improving present design procedures in manufacturing, with emphasis on control systems and the realisation of hierarchical and modular production management. Main theories to be developed are: 1) algebraic tools for the description of products and relevant manufacturing operations; 2) state equations for the dynamics of factories and production flows; 3) hierarchical control theory of the production processes providing a design methodology for control modules valid at any hierarchical level; 4) neural network algorithms as an alternative methodology. Theoretical results will be tested on manufacturing test cases, and links to present and future IT-technology will be investigated.
HIMAC addresses the theme of management and real-time control in manufacturing enterprises, subject to both exogenous and endogenous random events as well as to planned constraints. The most common and practical way to cope with such a complex and challenging problem is to use hierarchical management and control systems. In such systems, decisions and commands are taken top-down: the optimal plan at a given level providing reference to the lower control level. Disturbance and random events are attenuated or absorbed bottom-up; however it is common that discrepancies between optimal plans and actual production easily propagate and drift bottom-up; forcing recalculations of higher-level plans, which reveal themselves as not optimal or worse unfeasible. What is missing is a unifying methodology for the design of the various levels of the hierarchy, based on a specific mathematical formulation of the production phenomena taking place in factories. The main objective of this project is to fill in this gap, taking advantage of preliminary studies, results and experience of the partners.
APPROACH AND METHODS
The project will develop along the following lines:
- development of an axiomatic algebra allowing modelling of manufacturing products and operations at any level of detail and independently of the manufacturing sector
- modelling of factory dynamics as a network of three dynamic elements: stores, transport and manufacturing units and development of rules for aggregating detailed networks
- application of mathematics and feedback control theory to develop a unifying theory for designing hierarchical control algorithms, capable of driving production against failures and uncertainties
- test of the hierarchical control algorithms on simulated test cases, with the aim of assessing and refining the results and comparing the new methodology with present practice
- investigation about links and impacts on present and future ITs for manufacturing systems
- investigation of the role of various forms of neural networks as basic elements of specific algorithms for manufacturing modelling and control.
The results are expected to lay the foundations for developing a new generation of IT-based production control systems applicable to any discrete manufacturing process. The research results should have impacts on CIM methods, standards and products.
Sven Müßig, last update 07-nov-1995. Your feedback is welcome.