In this article, we considered the fixed‐time stability (FXT) of a type of discontinuous dynamical system. First, we introduced some new FXT stability results via variable substitutions and using inequality techniques, which are more accurately estimate the upper bound of settling time (ST). Then, based on the established results and using the differential inclusion theory, we investigated the FXT

This article presents an event‐triggered approach to security control for networked systems by using hybrid attack model. Stochastic deception attacks, replay attacks, and denial of service attacks are assumed to occur in the communication network. The main contribution of the article is that an event‐triggered control strategy is presented to stabilize the networked systems based on the hybrid attacks

Conventionally, the dual‐loop PI controllers are designed for the single‐phase boost power factor correction (PFC) converters operating under continuous conduction mode (CCM), which is not available to perform rapid adaptations to plant uncertainties caused by the different operation modes and the parameter variations. In order to improve the control performance and robustness, a cascaded model‐free

In this article, the problem of output‐feedback stabilization for a class of stochastic high‐order nonlinear systems with stochastic inverse dynamics and multidelay is studied. In the control scheme, an output‐feedback controller with a reduced‐order observer is designed to globally stabilize the whole system. Different from the classical literature on stochastic upper‐triangular systems, a high‐gain‐based

Most autonomous systems can be described by Euler–Lagrange (EL) model. This article investigates the problem of prescribed time tracking control for EL systems in the presence of modeling uncertainties, prescribed performance requirements and time‐varying state constraints. Two proportional–integral (PI)‐like control schemes with time‐varying gains are developed with several favorable features: (1)

Many important engineering systems can be classified as Euler–Lagrange (EL) systems. In this work we develop a new Proportional‐Integral‐Derivative (PID) ‐based tracking control solution for uncertain EL systems subject to actuation failures and saturation. Two set of control algorithms are developed using robust adaptive and neuroadaptive methods, which are shown to exhibit several salient features:

In this paper, distributed security filtering is investigated for networked switched systems under the round‐robin protocol (RRP). In order to fully take the practical situation into account, a cyber attack without additional bounded constraint is considered by introducing the neural network approximate technique. Moreover, the scattered sensor nodes are universally utilized to transmit and collect

In this article, we present a virtual control contraction metric (VCCM) based nonlinear parameter‐varying approach to design a state‐feedback controller for a control moment gyroscope (CMG) to track a user‐defined trajectory set. This VCCM based nonlinear (NL) stabilization and performance synthesis approach, which is similar to linear parameter‐varying (LPV) control approaches, allows to achieve exact

This article studies the trajectory tracking of nonholonomic mobile robots by using geometric control methods, with extension to consensus tracking and formation tracking. Different from the system model given in the Euclidean space, we establish the dynamics of mobile robots on the tangent bundle of the Lie group, which is a global and unique description independent of local coordinates. Firstly,

This study investigates periodic event‐triggered (PET) output‐feedback control method for nonlinear systems with quantized states and multisource disturbances. Based on a PET extended state observer, a novel PET composite control method is proposed. It not only can deal with the deterministic and stochastic disturbances but also can handle the quantization in the data transmission process. A PET extended

In this article, passivity‐based sampled‐data control for Markovian jump systems (MJSs) with stochastic sampling is conducted by virtue of the looped‐functional approach. First, based on the input delay approach, the MJS under stochastic sampled‐data control is modeled as a time‐varying continuous‐time system with a random variable. Second, a time‐dependent looped‐functional is developed, which only

This article is concerned with the quantized fault‐tolerant control (FTC) for consensus of multiple Lagrangian systems subject to stochastically switching networks, actuator and sensor faults. First of all, a reliable quantized FTC algorithm is developed under Markov jump networks (MJNs), where the communication signal is first quantized before transmitted to develop controllers, and the communication

In this article, the problem of event‐driven output feedback control is addressed for discrete time‐varying systems with external disturbances. To estimate the unmeasured system states and external disturbances, a novel time‐varying extended state functional observer is designed. Then, an event‐driven control scheme is proposed to reduce the utilization of the communication resources, and the optimal

In this article, event‐triggered model predictive control is used for simultaneous tracking and formation of a multi‐vehicle system with collision avoidance and obstacle avoidance. An event‐triggered mechanism is established to reduce computational burden in the model predictive control strategy. A compatibility constraint is proposed to guarantee collision avoidance and convergence for the multi‐vehicle

This article deals with the dynamic sliding mode control (SMC) problem for unmatched nonlinear parameter‐varying systems. The unmatched nonlinear model refers to the systems matrices of control input and nonlinearity terms having inconsistent values and structures. A linear sliding surface function is constructed, and the resulting sliding mode dynamics is formulated into a full‐order descriptor nonlinear

Homogeneity is a key symmetry feature of dynamical systems, which provides an interrelation between the solutions with different initial conditions, and that global behavior of trajectories follows the local one. Existence of Lyapunov functions in the same class of homogeneous maps hints a way for their selection. In general, the homogeneous dynamical systems take an intermediate place between linear

In this article, we investigate the asymptotic behaviors of the solutions of nonlinear dynamic systems nearby an equilibrium point, when the nominal parts are subject to non‐necessarily small perturbations. We show that, under some estimates on the perturbation term, the equilibrium point remains (globally) uniformly exponentially stable. The obtained stability results can easily be applied in practice

The global stabilization problem for a more extensive class of switched nonlinear systems is studied, in which control vector fields are allowed to vanish at some point, even for all the subsystems at the same time. The main work of this article is to design a control vector fields‐dependent switching law and a bounded switching controller to stabilize the switched nonlinear systems. First, a sufficient

In this article, the lateral path following problem of unmanned ground vehicle with bounded disturbances is studied. A dual‐mode model predictive control (MPC) algorithm based on adaptive event triggered mechanism is proposed. Compared with the existing MPC algorithm, adaptive event triggered model predictive control (AEMPC) can ensure the tracking accuracy and reduce the optimization computation.

This article investigates a resource allocation problem of second‐order nonlinear multiagent systems. The resource allocation problem arises from many fields such as economic dispatch, network utility maximization, and demand response. Due to the dynamics of agents, we cannot solve this problem by using existing resource allocation algorithms. In order to achieve the optimal allocation, we propose

A novel sliding mode repetitive control scheme is proposed for discrete‐time systems. It aims to address aperiodic disturbances, and simultaneously address a set of disturbances of known frequencies that can be unrelated. The sliding mode handles the former, and a repetitive control algorithm deals with the latter, creating a low‐order sliding model repetitive control law. The approach addresses each

In this study, event‐triggered fault estimation (FE) problem for a class of discrete‐time dynamic systems subject to sector‐bounded nonlinearity and time‐varying coefficients is investigated. For a given event‐triggered measurement transmission scheme, the event‐induced output non‐persistence for the fault estimator is modeled by norm‐bounded observation uncertainty. After giving a suitable H∞ performance

The pth moment input‐to‐state stability and the pth moment integral input‐to‐state stability of stochastic systems with Markovian switching are investigated in this article. Sufficient conditions are provided by indefinite multiple Lyapunov functions (iMLFs) with a time‐varying sojourn time condition. These criteria quantify the stability of each individual subsystem with time‐varying infinitesimal

In this article, the incremental stability problem is addressed for stochastic time‐varying impulsive and switching systems. Both cases of stable continuous subsystems with destabilizing impulses and unstable continuous subsystems with stabilizing impulses are fully considered. By resorting to contraction theory and the Lyapunov function approach together with the dwell time technique, sufficient criteria

This article proposes a novel asynchronous advantage actor‐critic (A3C) learning‐based dynamic event‐triggered mechanism for the decentralized load frequency regulation to alleviate the local‐area communication burden and influence of the load fluctuations. The proposed dynamic event‐triggered mechanism applies the A3C algorithm to optimally adjust the threshold of the event‐triggered function in real

In this paper, a discrete active disturbance rejection control (DADRC) scheme is proposed to manipulate linear input–output systems with zero dynamics. The DADRC is formulated according to the relative degree of the system output and is designed to track a reference and cancel both internal uncertainties and external disturbances. A parameter tuning method is also presented based on a part of the model

In this article, the problem of distributed state estimation is addressed for nonlinear systems based on the unscented Kalman filter (UKF) framework. The local estimates are obtained from distributed UKFs with stochastic event‐triggered schedules. The consensus of estimated states is achieved by employing the covariance intersection fusion method, while a novel event‐triggered strategy for the node‐to‐node

Recently, a first‐order differentiator based on time‐varying gains was introduced in the literature, in its nonrecursive form, for signals having a second‐order derivative bounded by a known time‐varying function, where such time‐varying bound has a logarithmic derivative bounded by a known constant. It has been shown that such differentiator is globally finite‐time convergent. In this article, we

This article studies the problem of event‐triggered consensus for linear multiagent systems. Leaderless and leader‐following cases are considered here. By adopting adaptive technology and utilizing the relationship between parameters, novel fully distributed control schemes are proposed. Both the control updates and the communication consumption between agents can be declined under the designed hybrid

This paper addresses the distributed bipartite time‐varying formation control for uncertain linear multi‐agent systems under limited communication resources. First, the distributed static bipartite control protocol with sampled data is proposed to address the time‐varying formation issue. It is noteworthy that in both controller updating and triggering condition monitoring, the communication is only

Periodic event‐triggered control (PETC) evaluates triggering conditions only at periodic sampling times, based on which it is decided whether the controller needs to be updated. This article investigates the global stabilization of nonlinear systems that are affected by external disturbances under PETC mechanisms. Sufficient conditions are provided to ensure the resulting closed‐loop system is input‐to‐state

This article develops an adaptive finite‐time stable control algorithm for an accurate manipulation of robot arms considering unknown model parameters and external disturbances. First, a state‐dependent twisting control algorithm is developed for the robust manipulation of robot arms under the consideration of bounded unknown uncertainties conditions. The more challenging problem of robust control

This article is concerned with the issue of adaptive prescribed performance tracking control for a class of pure‐feedback nonlinear systems with full‐state time‐varying constraints. By using the hyperbolic tangent function as nonlinear mapping technique, the obstacle of the full‐state constraints is resolved. A novel adaptive control method is proposed by prescribed performance control with command

This study proposes an adaptive constraint‐following control scheme for an uncertain nonlinear mechanical system. The concerned system is required to follow a class of (holonomic and nonholonomic) equality constraints. Uncertainties (possibly fast time‐varying) exist in the dynamics equation and the equality constraints. Meanwhile, the system contains state measurement errors. Both the uncertainties

In this article, an implicit Euler algorithm for digital implementation of constrained stabilization is studied for the second‐order systems. For that, a switching controller is designed in a discrete‐time framework such that the system's position output converges to some predefined range, that is, ϱ ∈ (−ε, ε) in finite‐time while the velocity output converges to the origin, that is, , in finite‐time

This article analyzes the stability‐related properties of long short‐term memory (LSTM) networks and investigates their use as the model of the plant in the design of model predictive controllers (MPC). First, sufficient conditions guaranteeing the Input‐to‐State stability (ISS) and Incremental Input‐to‐State stability (ISS) of LSTM are derived. These properties are then exploited to design an observer

This article investigates the fault‐tolerant consensus problem for switched multiagent systems with input saturation. Actuator faults including partial loss of effectiveness, outage, bias, and stuck are all considered in switched general linear systems. By utilizing the adaptive projection algorithm, low gain feedback theory, and average dwell time method, novel saturated consensus protocols are designed

In this paper, we study the Robust Minimal Controllability and Observability Problem (rMCOP). The scenario that motivated this question is related to the design of a drone formation to execute some task, where the decision of which nodes to equip with a more expensive communication system represents a critical economic choice. Given a linear time‐invariant system for each of the vehicles, this problem

This article establishes a descriptor regular form and shows its applications in observer‐based integral sliding mode controllers design of descriptor systems. A reduced‐order linear observer and a full‐order descriptor sliding mode observer are, respectively, designed to estimate the state variables of the descriptor system under consideration. Necessary and sufficient conditions for the existence

In this article, the robust adaptive output tracking control problem is addressed for a class of nonlinear systems with nonlinear dynamics and unknown system parameters. The nonlinear dynamics including internal parameter uncertainties and external disturbances are formulated as time‐varying state/input‐dependent perturbations. Radial‐basis function neural networks (RBFNNs) are developed to approximate

In this article, we present an active fault tolerant control scheme based on fault detection and isolation (FDI) for a class of uncertain systems subject to sensor faults. The FDI unit consists of a fault detection (FD) module and a fault isolation (FI) module, to determine when and where the sensor fault happens. It is noted that the FD module is based on a proposed adaptive interval observer where

This research proposes a nonlinear adaptive controller based on a hierarchical sliding mode control (HSMC) framework to stabilize the operation of a ridable ballbot based on the full nonlinear dynamics (FND). The FND of ballbots is a multiple‐input‐multiple‐output underactuated system with a non‐invertible input matrix. By applying a novel approach to transform the FND into two subsystems, the invertibility

This article addresses the problem of velocity‐free fixed‐time attitude cooperative control for multiple spacecraft under directed communication graphs and in the presence of bounded disturbances. A distributed fixed‐time state observer is designed to estimate the leader's attitude states and a fixed‐time extended‐state observer is presented to obtain accurate estimates of both unmeasurable angular

This paper investigates the input‐output gains, including ℓ1‐ and ℓ∞‐gains and L1‐ and L∞‐gains, of discrete‐time and continuous‐time positive periodic systems. For the discrete‐time case, the input–output gain can be characterized by linear inequalities. For the continuous‐time case, the input–output gain characterization problem turns into the existence problem of a positive periodic vector function

Stability of equilibria of a nonlinear delay differential equation is investigated under stochastic perturbations. The use of Stiltjes integrals allows to consider both discrete and distributed delays in the investigated equation. Obtained conditions of stability in probability are formulated in terms of linear matrix inequalities. The proposed method of investigation can be applied to a number of

This article investigates the problem of mode‐dependent intermediate variable‐based fault estimation for Markovian jump systems subject to time‐varying delay, exogenous disturbance, process, and sensor faults. The advantages of the proposed design method are: (i) it estimates not only the unknown fault signals, but also the immeasurable states of the system; and (ii) it relaxes the observer matching

In this paper, a finite‐time adaptive fault‐tolerant control (FTC) scheme is researched for a class of nonlinear systems with unmodeled dynamics, where the dynamic system is switched. Due to the complexity of the system and switching characteristics, it is not easy to solve the tracking problem in a finite time adopting existing approaches. In this study, a new FTC method is presented. This is completed

In order to acquire high‐performance tracking control for a class of nonlinear systems with matched and mismatched modeling uncertainties, a disturbance‐compensation‐based nonlinear robust controller with a continuous control law is integrated via a novel asymptotic‐filter‐based backstepping approach. Specially, a set of novel asymptotic disturbance observers with exact estimation performance is constructed

We present a robust synthesis algorithm for uncertain linear time‐varying (LTV) systems on finite horizons. The uncertain system is described as an interconnection of a known LTV system and a perturbation. The input–output behavior of the perturbation is specified by time‐domain Integral Quadratic Constraints (IQCs). The objective is to synthesize a controller to minimize the worst‐case performance

In this article, we propose a networked control architecture to ensure the plant's safety in the presence of cyber‐attacks on the communication channels. In particular, we consider systems subject to both state and input constraints that must be preserved for safety reasons despite any admissible attack scenario. To this end, first, two different detectors are proposed to detect attacks on the setpoint

This article studies the quantized feedback stabilization problem for nonlinear control systems with external disturbance. To ensure the transmission data rate as minimal as possible, a coarse quantizer is applied, and the quantization procedure has two stages: zooming‐out stage and zooming‐in stage. To detect the effects of the disturbance and to utilize quantization regions as less as possible, both

This paper firstly discusses the existence and boundedness of unique global solution for highly nonlinear switched stochastic systems (SSSs) with time delays, where the switching signal is deterministic switching signal. Although the existence and boundedness of unique global solution can be obtained under local Lipschitz condition and Khasminskii‐type condition, highly nonlinear SSSs with time delays

The objective of this work is to propose new families of finite‐time controllers providing bounded and unbounded control signals. We show that this new family of controllers can be applied to solve the regulation problem for robot manipulators in finite‐time with unbounded and bounded torques. The key idea to accomplish this objective is to propose a novel family of Lyapunov functions, which is more

This paper considers the distributed filtering problem for discrete‐time nonlinear systems with colored measurement noise obeying a nonlinear autoregressive process in sensor networks. A novel block‐decomposed information‐type filter for such systems is proposed in a centralized fusion structure, by using the statistical linear regression to deal with model nonlinearities and the measurement difference

The design of an adaptive observer for a class of multi‐input multi‐output Lipschitz nonlinear systems with uncertainties and multirated outputs is proposed in this paper. The sampling instants of the different outputs can be asynchronous and irregular. The exponential convergence of the proposed observer is proved with the help of a Lyapunov approach. The stability is ensured, provided that some conditions

In this article, a protocol‐based H∞ filtering problem is investigated for piecewise linear (PWL) systems with mixed delays. Stochastic access protocol (SAP) is utilized to schedule the signal transmission via a constrained communication channel, under which only one measurement value can be transmitted to the filter at each time instant following a Markov process. When SAP is applied to PWL systems

This paper extends the existing results on the robust H∞ filtering problem for singular Markovian jump systems. Firstly, the double variables‐based decoupling principle and the variable substitution principle are proposed, respectively. Secondly, the two principles are employed to formulate a robust H∞ filter design condition, which ensures the filtering error system to be stochastically admissible

This article is concerned with the dynamic output‐feedback control problem for continuous‐time switched linear systems with persistent dwell‐time (PDT). Considering the quasi‐periodic property of PDT switching, a discretized quasi‐time‐dependent (QTD) control scheme is proposed by means of a multiple discretized QTD Lyapunov function approach. This control scheme is devoted to designing discretized

In this article, based on radial basis function neural network (RBFNN) and disturbance estimator (DE), an adaptive sampled‐data observer design scheme is proposed for a class of nonlinear systems with unknown Prandtl–Ishlinskii (PI) hysteresis and unknown multiple disturbances. To begin with, we investigate a class of sampled‐data nonlinear systems and present corresponding sufficient conditions ensuring

A distributed impulsive algorithm is presented for solving large‐scale nonlinear optimization problems, which is based on state‐dependent impulsive dynamical system theory. The optimization problem, whose objective function is a sum of convex and continuously differentiable functions, is solved over a multi‐agent network system. The proposed algorithm takes distributed updates in continuous‐time part