Research On Some Issues Arisen In Networked Control Systems

With the rapid development of the network technology, networked control systems have gained more and more attention. So it is necessary to study the systems. In this paper, the development of the systems was introduced firstly. And now more and more researchers pay close attention to the progress of Industrial Ethernet. On the basis of the synthetically description of the research progress and presence of networked control systems, the related system modeling, state estimate, information time-delay, scheduling, communication constraints were analyzed in detail, and its prospects in the future are proposed also.First of all, in this paper we analyzed the effects brought by the network and introduced control network. We discussed constitutes of delay in the networked control systems and analyzed some factors of influencing delay.In this paper we compared inform scheduling of NCS with the scheduling of real time system and summarized scheduling arithmetic. In conclusion, we presented a scheduling arithmetic based Maximal Allowable Network time-delay.The delays in the networked control systems are inevitable and can degrade the system's performance and stability. A method for networked control systems with network induced delay was proposed using LMI-based delay-dependent optimization method. The method has provided the design of controller in the networked control systems. Some simulations show that the proposed method works well.The problems of data packet drop out in the networked control systems include single-packet transmission and multi-packet transmission. And we discussed the stability problem of data packet drop out in NCS by switching control method.