Internet-based Process Control Systems

Computer-based control has been widely used in the process industries. With the great development of the Internet and web technologies, Internet presents the great application potential to control domain. As a basis for the possible next generation of control systems, design of Internet-based process control has been received much attention in the recent years. The main aim of the research work for Internet-based process control systems is globally remote monitoring and adjustment of plants. It aims at adopting effective strategy to overcome uncertain Internet time delay influencing the dynamic performance of control systems while ensuring the safety operation for Internet-based process control systems.The main contribution of this thesis is to presents a whole new solution for dealing with the Internet delay for Internet-based control systems. New communication architecture and optimal control strategies are employed towards solving the problems associated with time-delay communication. Real-time Internet communication system has been implemented and addressed. In order to achieve an end-to-end communication, this solution is to provide a software-oriented mechanism to facilitate the real-time communication over the Internet for control systems. And two novel optimal control schemes, which are time-delay compensation with time-delay predictor and dual closed-loop predictive control strategy respectively, are designed to overcome the Internet transmission delay. The simulation results show the efficiency of them for overcoming the Internet time-delay.In detail, Section 1 introduces literature survey of research and contributions of the present studies and organization of the thesis in brief. Section 2 gives out a safe real-time Internet communication architecture based on the existing real-time communication techniques. Simulation experiment is investigated to show the efficiency of the new data encryption algorithms for Internet-based real-timeapplications. Implementations of real-time Internet communication and simulation are expatiated in section 3. After analyzing the features of Internet transmission, two promising optimal control strategies are proposed to improve the dynamic performance of Internet-based control system in Section 4. Two proposed optimal control strategies have shown two promising ways to efficiently compensate the effect of the Internet delay on the control performance through the simulation study. The paper ends with the advice for the further work in chapter 5.