Network-based Dynamic Output Feedback Control Under An Event-triggered Communication Scheme

This thesis is concerned with event-triggered dynamic output feedback H? control for networked control systems with bilateral network.An output-based event-triggered communication scheme is introduced in the sensor side of a networked control system,that is,the control strategy that the sampled-data is transmitted to the controller side over a network is executed only when a certain event occurs.Such an event-triggered communication scheme is capable of effectively avoiding the transmission of redundant data,reducing the required energy consumption for transportation and decreasing the implementation cost of the whole control system to some extent while retaining a satisfactory system performance.It is physically difficult to measure all state variables of a control system in many practical situations due to complex environment,technological and economic constraints,and thus a dynamic output feedback controller is considered for a networked control system in the thesis.The main research contents of this thesis contain two parts:the first part is to study the dynamic output feedback H? control for a continuous time linear system under an event-triggered communication scheme,which takes into consideration the effects of network-induced delays in the bilateral network.The second part is to deal with the event-triggered dynamic output feedback H? control for a discrete-time linear system by considering the effects of network-induced delays and random packet dropouts in the bilateral network on the system.The work of this thesis is organized as follow:(1)The first chapter elaborates research background and significance of this work,recalls the research situation at home and abroad,and then introduces the main research problems of this thesis.(2)The second chapter studies the problem of network-based dynamic output feedback H? control for a continuous-time linear system under an event-triggered communication scheme.An output-based event-triggered comm-unication scheme is introduced to determine which sampled output should be transmitted at which time instants to a dynamic output feedback controller through the network.Under the event-triggered communication scheme,taking network-induced delays in both the sensor-to-controller channel and the controller-to-actuator channel into account,the resulting closed-loop system is modeled as a linear delay system with two interval time-varying delays by using an input delay approach.A Lyapunov-Krasovskii functional,using the information of the upper and lower bounds of these two interval time-varying delays,is constructed to derive an H? performance criterion and a controller design method in terms of linear matrix inequalities.Finally,a numerical example is given to validate the proposed method.(3)In the third chapter,the network-based dynamic output feedback H?control is considered for a discrete-time linear system under an event-triggered communication scheme.Firstly,an event-triggered communication scheme is introduced to decide whether or not the current sensor measurement should be sent to the controller via a network.Secondly,taking into consideration the effects of network-induced delays and random packet dropouts in the bilateral network,these random packet dropouts are assumed to obey Bernoulli random binary distribution,the resulting closed-loop system is modeled as a stochastic system with two discrete time-varying delays.By applying Lyapunov-Krasovskii stability theory,the sufficient condition that guarantees the system to be stochastic stable with an H? performance is obtained,and the design method of the corresponding dynamic output feedback controller is presented.Finally,the proposed method is verified effective by a numerical example.(4)In the fourth chapter,we summarize the present research work,and make a prediction about the future work.