Hierarchical control model for automated manufacturing systems

• Published in: Computers & industrial engineering 1983, Vol.7 (3), p.241-255
• Main Authors: Scott, Harold A., Davis, Robert P., Wysk, Richard A., Nunnally, Charles E.
• Format: Article
• Language: English
• Subjects: Automation; CAM; Computer aided manufacturing; Control systems; Flexible; Hierarchies; Manufacturing; Mathematical models; Systems
• ISSN: 0360-8352; 1879-0550
• DOI: 10.1016/0360-8352(83)90033-5

A mathematical model is presented to determine the hierarchical computer control requirements for a completely automated flexible manufacturing systems. This model can estimate the number and capacity of hierarchical computers needed to control a specified automated manufacturing system. The hierarchical control system is described by the major operating components common to all controlling computers and computer numerical controlled (CNC) machines: central processing unit, memory, input/output and communications. Each of these components is evaluated with respect to its operating speed and capacity. Costs are then determined as a function of the component's processing speed and capacity. A three-tier control system is examined. Starting with the CNC machines' speeds and capacities, each level of the computer hierarchical control system is modeled and related to the next tier by communication and data requirements. The physical machine layout required for a hierarchical control system is discussed. Part scheduling and process information requirements are also addressed. The model's utility is illustrated by an example using a typical manufacturing system. Optimization of this model is readily obtained using standard dynamic programming techniques. Being totally independent of any specific computer hardware technology, the model can be applied to present and future automated manufacturing systems.