H∞ controller design for networked predictive control systems based on the average dwell-time approach

This brief focuses on the problem of H∞ control for a class of networked control systems with time-varying delay in both forward and backward channels. Based on the average dwell-time method, a novel delay-compensation strategy is proposed by appropriately assigning the subsystem or designing the switching signals. Combined with this strategy, an improved predictive controller design approach in which the controller gain varies with the delay is presented to guarantee that the closed-loop system is exponentially stable with an H∞-norm bound for a class of switching signal in terms of nonlinear matrix inequalities. Furthermore, an iterative algorithm is presented to solve these nonlinear matrix inequalities to obtain a suboptimal minimum disturbance attenuation level. A numerical example illustrates the effectiveness of the proposed method

Stabilization of positive switched systems with time-varying delays under asynchronous switching

This paper investigates the state feedback stabilization problem for a class of positive switched systems with time-varying delays under asynchronous switching in the frameworks of continuous-time and discrete-time dynamics. The so-called asynchronous switching means that the switches between the candidate controllers and system modes are asynchronous. By constructing an appropriate co-positive type Lyapunov-Krasovskii functional and further allowing the functional to increase during the running time of active subsystems, sufficient conditions are provided to guarantee the exponential stability of the resulting closed-loop systems, and the corresponding controller gain matrices and admissible switching signals are presented. Finally, two illustrative examples are given to show the effectiveness of the proposed methods

Time-Delay Systems

Time delay is very often encountered in various technical systems, such as electric, pneumatic and hydraulic networks, chemical processes, long transmission lines, robotics, etc. The existence of pure time lag, regardless if it is present in the control or/and the state, may cause undesirable system transient response, or even instability. Consequently, the problem of controllability, observability, robustness, optimization, adaptive control, pole placement and particularly stability and robustness stabilization for this class of systems, has been one of the main interests for many scientists and researchers during the last five decades

Stabilization of switched neural networks with time-varying delay via bumpless transfer control

This paper investigates the stabilization of switched neural networks with time-varying delay. In order to overcome the drawback that the classical switching state feedback controller may generate the bumps at switching time, a new switching feedback controller which can smooth effectively the bumps is proposed. According to mode-dependent average dwell time, new exponential stabilization results are deduced for switched neural networks under the proposed feedback controller. Based on a simple corollary, the procedures which are used to calculate the feedback control gain matrices are also obtained. Two simple numerical examples are employed to demonstrate the effectiveness of the proposed results.Peer reviewe

Observer based decentralized load frequency control with false data injection attack for specified network quality and delay

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: Data will be made available on request.Load frequency control (LFC) aims to stabilize grid frequency fluctuations by countering load disturbances with generation-side controllers. In smart grids, demand response (DR) and electric vehicles (EV) offer alternatives to traditional frequency control, reducing reliance on costly generation-side controllers. These decentralized controls, interconnected through a shared communication medium, form a cyber-physical system, vulnerable to challenges like packet drops and false data injection (FDI) attacks. Additionally, consumer participation in DR introduces significant time delays. This paper derives stability conditions for LFC using a state feedback controller, estimating unobservable states with an observer while accounting for bounded disturbances and noise. This cyber-physical system, involving an observer, controller, and network, is modelled as an observer-based networked control system (NCS) using an asynchronous dynamical system (ADS) approach. The resulting switched system model is used to establish linear matrix inequality (LMI) criteria that ensure stability and determine observer and controller gains under specified packet drop rates, disturbances, and noise. The methodology is tested on various configurations, demonstrating that decentralized EV with LFC and DR improves system response, minimizes frequency fluctuations, and optimizes networked control bandwidth under given conditions