Control And Performance Analysis Of Networked Control Systems Based On The WSN

Wireless sensor network(WSN) is a wireless network. It is a self-organized and multi-hop wireless network composed of a large number of static or mobile sensors to sense collaboratively, gather, process and transmit the information of the perceived objects in the geographic area covered by network. The information is finally sent to the owners of the network. Wireless sensor network has been widely applied in many fields, but in most cases, it can only perform the role of environmental monitoring. The autonomic adjustment of the monitoring area is unable to be implemented. Networked control system(NCS) is a distributed and real-time feedback system which can make up for the deficiencies in such aspect. However, due to the different characteristics of them, many problems are still need to be solved to combine the WSN and NCS.The problems such as energy saving scheduling and packet loss of the NCS based on the WSN are considered in this paper. The main contents are as follows:Firstly, for the requirements of saving energy and extending the network lifetime in WSN, the nodes usually need to perform data fusion or transmission scheduling. A scheduling method based on the IAE performance index is proposed to reduce the amount of data being transferred and the congestion in WSN. Based on it, a model integrated scheduling and control for the NCS with random short-time delay is given. Furthermore, by the theory of Lyapunov stability and robust control, the design method of the state feedback controller which can ensure the H? performance index of the system is given.Secondly, because of the existence of communication network, the problem of packet loss is inevitable. It may even affect the stability of the whole control system. To solve this problem, a control system model for the packet loss of multi-nodes is given, and it can reconfigure dynamically according to the actual network situation.Finally, on the basis of the proposed model, the quantitative relationship of multiple network parameters(packet loss rate, the consecutive number of packet loss, network throughput) and the stability, exponential decay rate, quadratic performance index is given. The design method of the corresponding feedback controller is also proposed. Especially, when the sudden situation appears, it can be helpful for how to ensure the performance of the whole system.