Fei Minrui

Mean square exponential stabilization of networked control systems with Markovian packet dropouts

This paper considers the mean square stabilization for a kind of network control system (NCS) in which there exist network-induced delay and stochastic packet dropout between sensor and controller. This kind of NCS is modelled as a Markovian switched system with two subsystems. Using the average dwell time method, we design a state feedback controller to guarantee that NCS be mean square exponentially stable. An illustrative example is provided to demonstrate the effectiveness of the proposed results.

A Token-based MAC oriented Wireless Industrial Control Networks

After introducing the features and requirements in an industrial control networks, the properties of several wireless media access control protocols such as MACA, MACAW, IEEE802.il and WTRP are analyzed. An innovative MAC protocol based on token control is proposed to suit the requirements of WICN (Wireless Industrial Control Network). Logical ring under wireless link is defined; mechanisms of token resuming, joining and exiting of stations are introduced respectively. Then a simulation model has been made to compare the protocol with 802.11 upon OMNeT++ concrete event simulation platform. The results demonstrate that the throughput in the proposed protocol is ca.50% higher than CSMA/CA and has a smaller transmission delay. The protocol ensures the impartiality of channel medium access; reduces the transmitting delay of data and meets the time requirement of WICN.

Robust auto tune smith predictor controller design for plant with large delay

A robust Smith controller for plant with large delay is proposed. A nonlinear PD controller is design to auto tune on-line the parameters of robust controller such that the closed system is of robust stability as well as good dynamic performance. The simulation results show that the method can control the plant with large time-variable delay properly.

Network predictive control based on FARIMA time-delay model

Due to the self-similar property of network time-delay, a delay prediction method based on fractional autoregressive integrated moving average (FRIMA) model is proposed. Then the prediction method combined with Smith predictor is applied to networked control system (NCS). Simulation results prove that this control strategy can avoid the negative impacts of the varying network induced delay on control performances, and provide good performances and strong robustness.

An intelligence expert system based on hoop standard granulator

According to the analysis of the structure and technology, and then obtaining the energy consumption calculation formula, it comes to conclusion that the hoop standard granulator is a multivariate system with large time delay, which is also uncertain and nonlinear. Aiming at the problem that the hoop standard granulator cannot be controlled well by traditional methods, a technique was proposed, based on controlling the hoop standard granulator automatically by the expert system and SVM method. For good prediction performance, SVM with genetic algorithm is chosen to build the prediction model of output temperature and the main motor current, which is set as soft sense in the expert system. The expert system could be intelligent to solve the decoupling problem, by controlling feature identification, information processing machine, knowledge base, control rule and inference machine. In order to verify the design, based on reliable real-site data some experiments are conducted under the situation of disturbance. Finally the effect of expert control system and SVM is validated by simulation.

Exponential Stability of a Classic Networked Control Systems with Variable and Bounded Delay Based on Impulsive Control Theory

This paper studies exponential stability of networked control systems (NCSs) based on impulsive control with variable and bounded delay. A new application of impulsive control in networked control systems is provided in consideration time delay. By employing the Razumikhin technique and Lyapunov functions, an exponential stability criteria is established and the convergence rate is given. An example is discussed to illustrate our results.

Smith online identification predictive control and its application in STM

In this paper, a Smith online identification predictive control method was proposed for the system with delay. As we know, the Smith predictor, put forward by Smith (1959), resolves how to control the object with delay theoretically. However, due to the existing modeling error, a good control effect cannot be be acquired. It is even impossible to design a proper controller in order to stabilize the system. This paper incorporates system identification with the Smith predictor to-realize Smith online identification prediction control to compensate the delay. The identification module models the object dynamically. Based on the result, the delay is compensated by the Smith predictor. Experiments are presented to demonstrate that the method is of strong self-adaptability. Furthermore, it was successfully applied in the compensation control system of the AJ-I scanning tunneling microscope (STM) manufactured by Shanghai Aijian Nanometer science & technology development Ltd.

Clock synchronization algorithms for networked systems

Clock synchronization is a classical topic in the field of networked systems. Real-time industrial Ethernet and wireless sensor networks are two typical kinds of networked systems that have important applications in modern industry. In industrial Ethernet, people usually adopt the IEEE 1588 clock synchronization mechanism, and in wireless sensor networks, people often employ a distributed synchronization algorithm due to limited resources, unreliable communication links, and dynamic network topologies. In recent years, along with the development of a theoretical framework of distributed multi-agent consensus, there are an increasing number of scholars in the control community who are shifting their focus to the distributed clock synchronization algorithm and its applications, and there have been key breakthroughs in the algorithm convergence theorems. Owing to their robustness, flexibility, and ease of implementation, distributed consensus clock synchronization protocols have good prospects; however, many challenging scientific problems remain. In this paper, we summarize the latest research trends on hierarchical and distributed clock synchronization algorithms, especially highlighting the representative clock synchronization algorithms based on consensus control that were proposed in the last five years, and discuss the future directions that aim at providing valuable academic references for researchers working in relevant fields.

Professor Da Ruan in Shanghai University

I knew Prof. Da Ruan in 2007. At that time, Prof. Da Ruan was invited as a keynote speaker of 2007 International Conference on Life System Modeling and Simulation (LSMS2007) organized by Shanghai University. The conference was held on September 14-17, 2007, Shanghai, China. I was in charge of contacting keynote speakers as one of program committee members. I had many contacts with Professor Da Ruan by email. Prof. Da Ruan always replied me in time. Sometimes he replied me within one minute after I sent him an email. I felt he was energetic and was always working beside his laptop, which gave me a deep impression. Though he had not attended the LSMS2007 because of a conflict with another conference, he gave us a lecture titled “Lessons learned from computational intelligence applications in complex systems” on September 24, 2007 after the conference. Since then he was kindly engaged as an adjunct professor of shanghai university because of his great achievements, talent and intelligence.

Research of Networked Control System Based on P2P Network

Traditional control system is usually in Client/Server architecture because of the limit performance of embedded system and network technology. Real Time Data Server of C/S system is the bottleneck of system, and it is also influence on the safety, flexibility of system. With the promotion of the software and hardware of the embedded network controller, the P2P network technology enables us to reconsider the control network architecture to overcome the inherent shortcomings of the former C/S system. This paper introduces the control system based on P2P Network, through the analysis of calculation and simulation.