Limited Look-ahead Policies of Networked Control System Based on the Hierarchical Structure Model

摘要

Networked control system (NCS) regards communication network as a part of real-time control system, where the control system components use the communication network to exchange data, in order to realize the closed-loop control of plant. In this paper, a math model of NCS is given firstly according to NCS with delay and packet dropout; then in the basis of the math model and a plant of two-tank system, NCS is modeled as a hierarchical structure model, and limited lookahead policy (LLP) is designed. Finally, simulation research is carried out through True Time toolbox in the condition of simulated network, and the results show that compared the controllers are designed considering and without considering network factors in the NCS with delay and packet dropout, the former results a quicker response, a smaller overshoot value and system shock amplitude than the latter, therefore, the former has better control performance.