On Event-triggered Networked Control Systems

Networked Control Systems(NCSs)are closed-loop feedback control systems,in which the system components are connected through network channels.NCSs have been applied in many areas including industrial processes control,smart grid,smart transportation,due to their merits on reliability,low economic and easy maintenance.However,in there also exist huge information transmissions,network-induced delays,limited network bandwidth resources,which may deteriorate system performance or even lead to instability of the systems.The event-triggered transmission mechanism only transmits data whose error between the current sampled data and the most recent event-triggered data meets some specific event threshold condition.The event-triggered transmission mechanism could reduce the amount of data in the network,and improve the utilization of network resources.The main contents of this paper are as follows:(1)An event-triggered NCS with communication delays is studied.First,an event-triggered transmission mechanism is proposed for the networked control system is given,and an artificial time delay is introduced to model the system dynamics during the uncertain event-triggered intervals in the NCS.The two kinds of delays are carefully analyzed which are artificial delay and network induced delay,and their range is cut into two smaller intervals.Secondly,considering the impact of quantization error,a closed-loop networked control system model under the quantization mechanism is established.The Lyapunov functional method is used to obtain a sufficient condition for the uniform ultimate boundedness of the closed-loop system,and the corresponding controller is also designed.(2)An event-triggered distributed control system with channel cardinality constraint is studied.Firstly,an event-triggered transmission mechanism is proposed for the distributed control system.The Lyapunov function method is used to carry out the stability analysis and controller design for the system.Based on that,we study the channel cardinality constraint of the distributed control system,which is then converted into a sparse constraint condition on the state feedback controller gain.A hybrid integer programming method is used to design a controller that satisfies the sparse constraint condition.