Research On The GPC-Based Networked Control Systems

Feedback control systems connected through a real-time network are called networked control systems (NCSs), in which the information is exchanged using a network among control system components (sensors, controllers ,actuators, etc). The primary advantages of an NCS are the sharing of system resource, ease of system diagnosis and maintenance, and increased system agility.This paper introduces three kinds of NCSs: distributed control system (DCS), field control system (FCS) and Ethernet control system. The developing processes of each type and their advantages and disadvantages are also described.Based on the Ethernet control system, this paper analyzes the main problems existing in the NCSs, such as network-induced delay, the selection of sampling rate, discard of network transport packets and so on. At the same time, two main approaches for NCSs are discussed.According to the previous research experience, a new NCS model based on the generalized predictive control (GPC) is presented. With the prediction ability of GPC, this algorithm can successfully compensate the random delay of the NCSs to some extend, thus the stability of the control system is assured. A simulation experiment is also carried out in the platform of electrical and electronic internet-based laboratory at Zhejiang University.