The Design Of Controlling And Scheduling Methods For Wireless Networked Control System

As a new research area, Wireless networked control system (WNCS) is paid on more and more attention in recent years. Research results have been widely used in many fields, for example, military defense, control of industry and agriculture, bio-medical, environmental monitoring, anti-terrorism prevention and remote control. For a WNCS, stability is one of the essential issues.This dissertation is mainly about the research in the design of scheduling of node energy and controller, on the purpose of keeping a WNCS stable.Firstly, Considering that the network-induced delay is widespread in WNCS and has an important impact on the system stability, a discrete system with uncertain parameters of networked control system with long-time-vary delay is modeled. Combining the Lyapunov method, a method for design of the state feedback controller of the closed-loop system by the use of linear matrix inequality(LMI) is given.Secondly, on the basis of energy consumption analysis, the relationship between the sampling period and node life span is presented. Then a node energy controlling method, based on ajusting the sampling period dynamicly, is put forward. In this method, by using the known information of current remaining energy and consumption rate, node life span is predicted online. Under the premise that system is stable and sampling period can be scheduled, adjusting the sampling period in real-time to prolong the node life span. Otherwise, when the sampling period can not be scheduled, from the point of balancing the network nodes energy, a protocol for the allocation of transmission tasks is put forward and wireless communicatin energy model is established. Nodes with high energy consumption rate transfer its transmission tasks to nodes with low energy consumption rate, in order to reduce the energy consumption, prolong the node life span and increase network life.Finally, on the consideration that both controller and node energy have an impact on system stability, the WNCS with adaptive sampling period is modeled as a discrete switched system with temporary uncertain switching signal, from the view of the co-design of controlling and scheduling for WNCS. By introducing the feedback control strategy according to the switching state, the system stability is analyzed by the switched system theory and the constraints, which the controller gains and the residence time meet to guarantee the system is asymptotically stable, are given.