Some Thoughts and Practice on Performance Improvement in Distributed Control System Based on Fieldbus and Ethernet

Abstract

In this paper, the issue of improving control performance of a network-based control system in a different perspective from control algorithms was fully addressed. Some important performance-affecting elements including design of network architecture, configuration, and delay compensation were investigated and some methods presented. The presented design and implementation of a network-based cascade control system with a real laboratory pilot plant involved adopting two different control approaches based on Foundation Fieldbus and Ethernet, respectively. We presented some practically feasible approaches to improve control performance of the system, including improved function block configuration scheme, synchronization control methodology based on IEC61499, output estimation algorithm based on neural network, and methods for reducing network transmission by improving hardware and network architecture. Control effects under the proposed methodologies were also given. Experimental and on-site practice validated these methodologies.