This paper is concerned with event-triggered control for a switched system in network environments. Firstly, a novel event-triggering communication scheme with switching features is proposed. The switching features are taken into full consideration to guarantee the current sampled data to be transmitted if a switch occurs between the last sampling instant and the current sampling instant. The newly proposed event-triggering scheme is advantageous in dealing with switched networked control systems. Secondly, under the event-triggering scheme, an asynchronously switched time-delay system model is established by taking into account effects of network-induced delays. Finally, a mode-dependent state feedback controller gain and event generator parameters co-design method is proposed for the asynchronously switched time-delay system. System performance analysis demonstrates the effectiveness of the proposed methods.
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This chapter is concerned with active power sharingPower Sharing and frequency regulationFrequency regulation in an islanded microgrid under event-triggered communicationEvent-triggered communication schemes. A distributed secondary control scheme with a...
The synchronization problem of multiple/coupled reaction-diffusion neural networks with time-varying delays is investigated. Differing from the existing considerations, state delays among distinct neurons and coupling delays among different subnetworks are included in the proposed model, the assumptions posed on the arisen delays are very weak, time-varying, heterogeneous, even unbounded delays are permitted. To overcome the difficulties from this kind of delay as well as diffusion effects, a comparison-based approach is applied to this model and a series of algebraic criteria are successfully obtained to verify the global asymptotical synchronization. By specifying the existing delays, some M -matrix-based criteria are derived to justify the power-rate synchronization and exponential synchronization. In addition, new criterion on synchronization of general connected neural networks without diffusion effects is also given. Finally, two simulation examples are given to verify the effectiveness of the obtained theoretical results and provide a comparison with the existing criterion.
This paper is concerned with the controller design of networked control systems (NCS). A new model of the NCSs is provided under consideration of both the network-induced delay and the data packet dropout in the transmission. In terms of the given model, a controller design method is proposed based on a delay-dependent approach. The feedback gain of a memoryless controller and the maximum allowable value of the network-induced delay can be derived by solving a set of linear matrix inequalities. Two examples are given to show the effectiveness of our method.
Recent research has shown that one can obtain a less conservative stability criterion for a continuous-time linear system with a time-varying delay by introducing a Lyapunov-Krasovskii functional with a polynomial matrix on the time-varying delay. This paper aims at analysing the stability of discrete-time linear systems with time-varying delays by introducing a delay-square-dependent Lyapunov functional. A novel convex method is presented to formulate a less conservative stability criterion, which is demonstrated through numerical simulation. Moreover, it is also shown that, if the polynomial inequality method is employed, the resultant stability criterion is inapplicable due to its extremely high numerical complexity.
This paper is concerned with H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control for a class of network-based T-S fuzzy systems with available asynchronous constraints on membership functions. Since a fuzzy controller in a network environment depends on available sampled-data measurements of premise variables and feedback states, the closed-loop system is represented by an asynchronous T-S fuzzy system with interval time-varying delay. Notice that the existing methods cannot be used to design the fuzzy controller for the closed-loop system because common product terms of membership functions in the asynchronous fuzzy system cannot be grouped. Instead, a novel fuzzy control design method is proposed by introducing upper bounds of asynchronous errors of membership functions with some free weighting matrices. New criteria on the existence of a network-based H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> controller are derived. The effectiveness of the proposed method is illustrated by a numerical example.
The network-based modelling and active control for an offshore steel jacket platform with an active tuned mass damper mechanism is investigated. A network-based dynamic model of the offshore platform is first established. A network-based state feedback control scheme is developed. Under this scheme, the corresponding closed-loop system is modelled by a system with an artificial interval time-varying delay. Then, a delay-dependent stability criterion for the corresponding closed-loop system is derived. Based on this stability criterion, a sufficient condition on the existence of the network-based controller is obtained. It is found through simulation results that (i) both the oscillation amplitudes of the offshore platform and the required control force under the network-based state feedback controller are smaller than those under the nonlinear controller and the dynamic output feedback controller; (ii) the oscillation amplitudes of the offshore steel jacket platform under the network-based feedback controller are almost the same as the ones under the integral sliding mode controller, while the required control force by the former is smaller than the one by the latter.
This paper is concerned with leader-follower synchronization of complex dynamical networks with sampled-data control. By sampling the signal from the leader at some discrete time instants and using a zero-order hold function, synchronization is achieved between the network and a desired orbit, known as the leader. By applying Lyapunov functional approach and the property of the network topology matrix, a delay-dependent criterion is derived. It is shown that synchronization of N coupled dynamical systems with a leader can be recast into the stability of N decoupled systems, in which eigenvalues of the network topology matrix are involved. Finally, a chaotic neural network is used to illustrate the effectiveness of the proposed method.
This paper is concerned with global asymptotic stability of a neural network with a time-varying delay, where the delay function is differentiable uniformly bounded with delay-derivative bounded from above. First, a general reciprocally convex inequality is presented by introducing some slack vectors with flexible dimensions. This inequality provides a tighter bound in the form of a convex combination than some existing ones. Second, by constructing proper Lyapunov-Krasovskii functional, global asymptotic stability of the neural network is analyzed for two types of the time-varying delays depending on whether or not the lower bound of the delay derivative is known. Third, noticing that sufficient conditions on stability from estimation on the derivative of some Lyapunov-Krasovskii functional are affine both on the delay function and its derivative, allowable delay sets can be refined to produce less conservative stability criteria for the neural network under study. Finally, two numerical examples are given to substantiate the effectiveness of the proposed method.
This paper is concerned with modelling and dynamic output feedback (DOF) controller design for networked control systems (NCSs) with packet dropouts, network-induced delays and data drift. First, the polytopic-uncertainty-based data drift is introduced to formulate some new models for closed-loop NCSs, where packet-dropouts and network-induced delays from both the sensor-to-controller channel and the control-to-actuator channel are taken into account. Second, based on the new models, several sufficient conditions are derived such that the closed-loop NCSs is mean exponentially stable with a prescribed H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance. Third, an iterative algorithm is proposed to solve out the desired DOF controllers. A numerical example is finally taken to show the effectiveness of the method proposed in this paper.
In this paper, predefined-time leader-following (LF) consensus is investigated for multi-agent systems (MASs) with collision avoidance. A monotone system-based controller is proposed to maintain the order of a MAS. Particularly, two sufficient conditions are derived to guarantee collision-free coordination of the MAS, while realizing LF consensus in predefined-time. Numerical examples including comparison studies are provided to verify the effectiveness of the proposed controller.
In this paper, a linear unbiased minimum-variance filtering problem is considered for a class of systems with randomly multi-step sensor delays. A new mathematical model is established for the multi-step sensor delays. Different from the augmented method for dealing with delayed systems, a linear unbiased minimum-variance filter design method is proposed without augmenting the state vector, which effectively reduces the filter dimensions. A recursive algorithm for calculating the filter gain matrix is developed. The simulation results illustrate the effectiveness of the proposed method.
