Event-triggered Non-fragile Control Of Switched Positive Systems

In practice,there exist many control systems that can be modeled as positive systems,whose states are always non-negative.Switched positive systems are a special kind of hybrid systems composed of positive subsystems and a switching law.Such systems are employed in various practical systems such as water management systems,urban transportation systems,chemical processes,etc.In most existing systems,the time-triggering mechanism is generally adopted.The time-triggered control strategy adopts a fixed sampling interval to update the input.It may increase the communication burden and the design cost.In order to overcome these disadvantages,an event-triggered strategy is introduced.It is obvious that network utilization is not fixed and it varies with the variable of network capacity.A hybrid-triggered control method is proposed,which switches between time-triggered control and event-triggered control.What's more,non-fragile control is an effective way to deal with actuator saturation,nonlinearity and unpredictable external attacks,which are inevitable in practical processes.Considering the advantages of the event-triggering mechanism,the hybrid-triggering mechanism and the nonfragile control,it is meaningful to design the non-fragile controller for switched positive systems under the event-triggered and the hybrid event-triggered strategies.Based on these points,this thesis proposes the non-fragile control of switched positive systems under the event-triggering mechanism and hybrid mechanism.The details are as follows:The background and research significance are given in Chapter 1.First,the state of the art of switched positive systems and event-triggered non-fragile control is summarized.Moreover,the related research on actuator saturation,nonlinearity and unpredictable external attack is introduced.Finally,the main contents are summarized.An event-triggered non-fragile controller of switched positive systems is proposed in Chapter 2.First,a 1-norm based event-triggered control strategy is established.Then,combining the non-fragile and event-triggering mechanism,the controller is designed for switched positive systems.By utilizing linear co-positive Lyapunov functions and matrix decomposition,some sufficient conditions are obtained.Finally,the presented control approach is developed for switched positive systems with actuator saturation.The event-triggered non-fragile control of switched positive systems with random nonlinearities and controller perturbations is investigated in Chapter 3.The random nonlinearities and controller perturbations follow Bernoulli and Binomial sequences,respectively.An eventtriggering condition is first introduced for the systems.Then,the event-triggered non-fragile controller is proposed for the systems by constructing switched linear co-positive Lyapunov functions.All presented conditions are solved via the linear programming.Finally,different probabilities of nonlinearities and controller perturbations in each subsystem are further studied.The hybrid-triggered non-fragile control of switched positive systems with cyber attacks is considered in Chapter 4.The corresponding hybrid-triggered mechanism composed of time-triggering and event-triggering schemes.By means of a matrix decomposition approach and switched co-positive Lyapunov functions,the hybrid-triggered non-fragile controller of switched positive systems is introduced.The positivity and stability of the systems are achieved by considering the lower and upper bound of the systems,respectively.Finally,the presented control approach is developed to the switched positive systems with cyber attacks.Chapter 5 summarizes the main contents of the thesis and proposes some future research topics.