This article presents a robust model predictive control (MPC) for piecewise constant reference tracking based on a constrained linear model and a terminal constraint defined from the admissible equilibria set. The new robust MPC algorithm based on nominal predictions ensures recursive feasibility and convergence to an optimal target, but the terminal constraint is derived from an admissible equilibria

In this article, a unified adaptive neural event‐triggered control strategy is presented for uncertain multi‐input multi‐output (MIMO) nonlinear systems with dynamic and static constraints in the presence of unmodeled dynamics. By introducing an invertible nonlinear mapping based on hyperbolic tangent function, the constrained original system is transformed into an equivalent unconstrained MIMO pure‐feedback

This article exploits positive systems theory in the search for Zames–Falb multipliers for the analysis of discrete‐time Lurie systems, where the nonlinearity is assumed to be slope‐restricted. Although a similar problem has been tackled in a continuous time context, the results in discrete‐time take a different form and require a somewhat different approach to overcome certain technical problems.

The communication network is usually susceptible to effective communication channel capacity variation and transmission imperfections, which renders the connection among networked agents unstable. Motivated by this fact, we assume that the communication graphs are Markovian randomly switching, because the Markovian chain process is commonly employed to describe the network subject to Rayleigh fading

In this article, a novel unknown input interval observer (UIIO) is proposed for systems not satisfying the relative degree condition. In interval estimation, estimation errors are required not only positive but also convergent. For this purpose, some works combined unknown input observer with interval estimation, namely UIIO where by virtue of some transformations, some states are expressed as functions

This article considers the event‐triggered integral sliding mode control problem for fractional order T‐S fuzzy systems. A fuzzy error function and a mixed triggering threshold are proposed to design the event‐triggering mechanism, in which the fuzzy error function is used to design the triggering function. The mixed triggering threshold is composed of the time‐varying threshold with power function

To overcome the deficiencies of traditional disturbance observers in the presence of measurement uncertainty, an integral‐type observer‐based control using measured signals is proposed. The integral‐type observer is in terms of an explicit integral‐algebra form of measured signals. As a combination of the integral‐type observer and high‐gain controller, the observer‐based control is a proportional

This article is devoted to simultaneously solve the problems of fault estimation and synchronization for a class of delayed coupling complex dynamical networks. First, an intermediate estimator is established for each node with the aid of the relative information from the neighboring nodes. Second, a distributed memory state feedback controller is designed with respect to the estimated state values

An online adaptive optimal control problem for a class of nonlinear Markov jump systems (MJSs) is studied. It is worth noting that the dynamic information of MJSs is partially unknown. Applying the neural network linear differential inclusion techniques, the nonlinear terms in MJSs are approximately converted to linear forms. By using subsystem transformation schemes, we can transfer the nonlinear

In this article, the mixed H2/H∞ performance optimization is first formulated as a nonzero‐sum game, of which the sufficient condition guaranteeing the existence of the Nash equilibrium is derived using the Hamilton–Jacobi (HJ) theory. Then, Hamiltonian‐driven inequalities are presented to evaluate the H2 and H∞ performances. Using this Hamiltonian‐inequality driven approach, the coupled HJ equations

This article investigates the distributed fixed‐time event‐triggered consensus problem for linear multi‐agent systems with input delay. The Artstein‐Kwon‐Pearson reduction approach is used to convert the delay‐dependent system to a delay‐free one. Based on the delay‐free system, two distributed event‐triggered protocols are designed based on local information exchange to address the leaderless consensus

This article proposed a new adaptive integral sliding mode (ISM) based fault‐tolerant control (FTC) strategy to solve the actuator's faults and failures compensation problem for the class of Lipschitz nonlinear systems. A nominal state feedback virtual control law is designed first to stabilize the Lipschitz nonlinear system and to attain the desired nominal performance. To cater for the effect of

Nonlinear dynamical systems play a crucial role in control systems because, in practice, all the plants are nonlinear, and they are also a hopeful description of complex robot movements. To perform a control and stability analysis of a nonlinear system, usually, a Lyapunov function is used. In this article, we proposed a method to compute a control Lyapunov function (CLF) for nonlinear dynamics based

This note is concerned with the problem of crossing a target set between sample instants under the influence of bounded unknown disturbances. The proposed solution employs mixed‐integer linear programming and is less conservative compared with the standard approach of imposing pointwise‐in‐time constraints at the sample instants.

This article investigates the guaranteed cost control (GCC) problem of nonlinear rigid‐body attitude systems subject to control saturation. A novel methodology is proposed, by which the nonlinearities inherent in the attitude dynamics are effectively accounted for and thereby the existence of the proposed controller is cast into linear/bilinear matrix inequality conditions without resorting to model

In this article, the Tobit Kalman filtering problem is investigated for a class of discrete time‐varying fractional‐order systems in the presence of measurement censoring and stochastic nonlinearities under the Round‐Robin protocol (RRP). The fractional‐order dynamic model is described by the Grunwald–Letnikov difference equation, and the statistical means are utilized to characterize the stochastic

It is nontrivial to address the control problem of nonlinear systems with irregular constraining conditions (where the constraints, possibly time‐varying, asymmetric and alternating positively and negatively, would occur or disappear in the middle of system operation). In this work, we present a control design framework for uncertain pure‐feedback systems under the aforementioned constraining conditions

As is known to all that the Lyapunov‐Krasovskii functional (LKF) method plays a significant role in deriving exponential stability criteria of neural networks with a time‐varying delay. However, when the LKF method is adopted, the condition that a functional is required for a neural network with a delay varying in a delay interval is so strong that it may be hard to be satisfied and lead to a conservative

This article presents a dissipativity approach for robustness analysis using the framework of integral quadratic constraints (IQCs). The derived results apply for linear time‐varying nominal systems with uncertain initial conditions. IQC multipliers are used to describe the sets of allowable uncertainty operators, and signal IQC multipliers are used to describe the sets of allowable disturbance signals

As the backbone of Industrial 4.0, cyber‐physical systems (CPSs) are widely applicable in industrial processes. In this paper, a resilient control is designed for a class of two‐dimensional (2D) CPSs with the occurrence of Denial‐of‐Service (DoS) attacks. Firstly, we model the physical layer of CPSs as a 2D Fornasini‐Marchesini plant and set up the stability issue as preliminaries. Next, for CPSs suffering

Standard state estimation techniques, ranging from the linear Kalman filter (KF) to nonlinear extended KF (EKF), sigma‐point or particle filters, assume a perfectly known system model, that is, process and measurement functions and system noise statistics (both the distribution and its parameters). This is a strong assumption which may not hold in practice, reason why several approaches have been proposed

This paper is concerned with the reachable set estimation (RSE) problem for singular systems with both time‐varying delays and bounded peak disturbances. The objective is to search a bounded set that contains all the system states under zero initial conditions. By utilizing the theory of {1}‐inverse and Wirtinger‐based integral inequality, an improved criterion is established in terms of the linear

In this article, the problem of reduced‐order observer‐based controller design for a class of nonlinear time‐delay systems is addressed. First, we present sufficient conditions for the existence of the reduced‐order observer of nonlinear time‐delay systems. Then, a state feedback controller is designed to stabilize the systems. Furthermore, it is shown that the separation principle holds for stabilization

This article investigates the issue of cooperative fault‐tolerant fuzzy tracking control for a class of nonlinear multiagent systems subject to actuator failures and external disturbances under a directed network topology. By introducing the hierarchical control scheme, a fully distributed tracking control method is proposed. Specifically, the hierarchical control framework includes the upper layer

This article studies the cooperative fault‐tolerant control (FTC) problem of leader‐follower multiagent systems with process faults and heterogeneous Lipschitz nonlinearity via output regulation theory. The control objective is to convert the FTC problem into a cooperative output regulation problem such that all followers can track the leader regardless of process faults. Under directed communication

This article investigates disturbance attenuation problem for a class of Lipschitz nonlinear systems subject to unknown sensor disturbances/faults and large input delay. First, the Artstein model reduction method is applied to deal with the input delay and a descriptor observer is constructed to estimate the predicted state and sensor faults simultaneously. Then, a finite‐dimensional controller is

In this article, the design problem of ℓ2–ℓ∞ proportional–integral observer (PIO) is investigated for a class of discrete‐time systems with mixed time‐delays. The mixed time‐delays comprise both the discrete time‐varying delays and infinitely distributed delays. The round–robin protocol (RRP) is employed to schedule the data transmissions from the sensors to the observer so as to mitigate the communication

This article proposes a new strictly bounded real lemma (BRL) for continuous‐time singular Markovian jump systems (SMJSs) in terms of strict linear matrix inequalities (LMIs). While the previous studies have been done for SMJSs that do not have a path from disturbances to desired output, the proposed BRL covers SMJSs with disturbance‐contaminated output by introducing additional free matrix variables

This article devotes a practical finite‐time sampled‐data output consensus investigation for a class of nonlinear multiagent systems with unavailable velocities and undirected topology via output feedback. Noticing that the focused multiagent system features nonlinearities with non‐Lipschitz restriction, and the outputs of the agents are detectable only at the sampling instants, a reduced‐order observer

In this article, we present a decentralized control scheme for regulating input‐affine nonlinear interconnected systems. In particular, we propose a codesign strategy to synthesize a control policy and an event‐triggering threshold at each subsystem of an interconnected system to simultaneously optimize the subsystem performance and reduce the computational burden on the controllers by enforcing aperiodic

This article focuses on the parameter estimation for a class of nonlinear systems, that is, multi‐input single‐output or two‐input single‐output Hammerstein finite impulse response systems with autoregressive moving average noise. The key is to investigate new estimation methods for on‐line parameter estimation of the considered system. By using the gradient search and introducing the forgetting factor

This article studies the H∞ fault estimation (FE) problem for linear discrete time‐variant systems with actuator and sensor saturations. To handle the saturation nonlinearities for FE problem, a pair of an auxiliary linear model and an associated performance function augmenting from the conventional H∞ performance index are constructed. Based on this pair, the original FE problem is readdressed as

This article studies a class of asynchronous generalized H2 control problems for continuous‐time discrete‐state semi‐Markov jump linear systems. By constructing a Lyapunov function based on the semi‐Markov process, introducing a weak infinitesimal operator and applying the smoothness of the expectation, sufficient conditions are obtained to ensure stochastic stability and generalized H2 performance

This study proposes the nonfragile sampled‐data H∞ control design for a high‐speed train (HST) with parametric uncertainties. Unlike the existing studies, the HST model is formulated together with the damping force, parametric uncertainties, and uncertain factors. To guarantee the desired tracking speed of HST, and at the equilibrium state, the stability of relative spring displacement between two

In this article, we consider a problem of global exponential stabilization for a class of nonlinear systems with the perturbed nonlinearity by output feedback. We provide a newly designed observer‐based output feedback controller with three gain‐scaling factors to deal with extended structure of nonlinearity and larger growth rate of nonlinearity over the existing results. Utilizing three gain‐scaling

This article is concerned with the scalable distributed H∞‐consensus filtering problem for a class of discrete time‐varying systems over sensor networks with the Round‐Robin protocol (RRP). The challenge comes from the fact that the time‐varying parameters of the network are subject to randomly occurring norm‐bounded uncertainties and the measurement outputs of the sensor nodes are saturated due to

This paper aims to propose a novel idea for the modeling and trajectory tracking control of a lower limb rehabilitation robot. A polynomial nonlinear uncertain model is established to deal with the difficulty of accurate modeling for the lower limb rehabilitation robot with complex dynamic characteristics. A high‐order nonlinear disturbance observer (HONDO) is utilized to estimate the lumped disturbance

The control method based on the equivalent‐input‐disturbance (EID) estimator and the Luenberger state observer has received much attention in recent years. However, the property of EID‐based control systems is still not well investigated. A number of design procedures were proposed but lacked sufficient theoretic justification. In this article, the two‐degree‐of‐freedom nature of an EID‐based control

Model predictive control allows to provide high performance and safety guarantees in the form of constraint satisfaction. These properties, however, can be satisfied only if the underlying model, used for prediction, of the controlled process is sufficiently accurate. One way to address this challenge is by data‐driven and machine learning approaches, such as Gaussian processes, that allow to refine

In this article, boundary control strategy is adopted to suppress the vibration of a flexible three‐dimensional (3D) marine riser simultaneously against both sensor and actuator faults. The flexible 3D marine riser is a distributed parameter system modeled as partial differential equations. During normal operation of the system, all the system components will behave optimally. However, if the sensor

This article undertakes the problem of simultaneous estimation of state and process faults in linear parameter varying systems. For this purpose, a novel strategy that exploits recent results on the design of observers for quadratic parameter varying systems is developed, and a complete design procedure is described. First, it is shown that by treating the process faults as additional states to be

This article studies the problems of exponential stabilization and ‐gain performance for networked control systems (NCSs) with transmission delays and periodic denial‐of‐service (DoS) attacks by exploring a resilient event‐triggered communication mechanism. First, a new resilient event‐triggered mechanism is developed to eliminate the adverse effects of network congestion caused by DoS attacks and

This article presents an adaptive discontinuous higher order sliding mode control (HOSMC) strategy for a disturbed chain of integrators of order n. This strategy employs a barrier function‐based dual layer adaptation and it ensures the convergence of the sliding variable and its (n − 1) first derivatives to zero without requiring any information on the bounds of the disturbances or their derivatives

This article presents a distributed model predictive control algorithm for power flow systems that can maintain overall stability when the system equilibrium configuration changes. The dynamics of the large‐scale power flow systems can be described by transportation, conversion, and storage of energy among and across subsystems. By strategically choosing the output for each subsystem and augmenting

This paper studies the problem of distributed robust actuator fault detection for multi‐agent systems composed of multiple unicycle‐type mobile agents with chained form dynamics. This objective is achieved through the design of cascades of predefined‐time sliding mode observers to give an exact estimate of the global system state, whereby the settling time is a parameter defined in advance, which does

In this article, a second‐order system, which is affected by disturbances and uncertainties, with a saturating actuator is considered. A novel robust feedback control law is designed based on the sliding mode technique. The twisting and the continuous twisting algorithms are incorporated into the design, which is based on level curves of a Lyapunov function. The performance of the standard continuous

This article presents a robust adaptive controller for chaos synchronization using the Szász–Mirakyan operator as a universal approximator. In accordance with the universal approximation theorem, the Szász–Mirakyan operator, an extended version of the Bernstein polynomial, can approximate uncertainties, including unmodeled dynamics and external disturbances. This fact is completely discussed in this

This paper studies finite‐time annular domain stability (FTADS) and stabilization for stochastic Markovian switching systems driven by both Wiener and Poisson noises. Firstly, new sufficient conditions, based on the common parameter approach (CPA)/mode‐dependent parameter approach (MDPA), are presented to make the stochastic Markovian switching systems FTADS. Secondly, the finite‐time annular domain

This article presents the quantitative feedback theory (QFT) based multivariable controller for the vertical and the pitch angle motion of a half‐car suspension system. A coupled half‐car system with significant uncertainty, due to sprung masses variation, poses a challenging control problem. Multi‐input multi‐output (MIMO) QFT method is used for this purpose which involves converting the actual MIMO

Subsequent to publication, the Funding information section of Arabi et al.1 was removed from the article. This is now corrected in the online and print version of the article.

This article presents a novel framework for the output regulation of rational nonlinear systems subject to input saturation, where the controller structure is composed by an internal model generator in series with an output feedback stabilizing stage. In order to address the effects of control saturation, we propose the use of an antiwindup compensation loop into both internal model and stabilizing

This paper addresses the local stabilization problem of nonlinear systems described by Difference‐Algebraic Representations (DAR). A novel set of sufficient Linear Matrix Inequalities (LMI) conditions are developed to design gain‐scheduled state feedback controllers. The proposed approach uses parameter‐dependent Lyapunov functions and new auxiliary decision variables aiming to obtain less conservative

In this study, the finite‐time control for uncertain positive systems with impulses using a hybrid state feedback control mechanism is investigated. The hybrid state feedback double control strategy is utilized, which includes impulsive state control scheme and continuous state feedback control scheme. A type of time‐varying Lyapunov copositive function is constructed. Considering different impulsive

In the presence of complex unknowns consisting of system dynamics and environmental disturbances, it is rather meaningful to exactly track an unmanned surface vehicle (USV) to the desired trajectory in practical scenarios including routing inspection, marine survey, and guard patrol, etc. In this paper, the exact trajectory tracking problem is solved by establishing a finite‐time extended state observer‐

This article considers the stabilization problem of continuous‐time semi‐Markovian jump systems. A kind of stochastically scheduled controller is proposed to realize the aim. It could also suffer a case that no controller is added to subsystems during some time slices. Based on a Lyapunov approach, sufficient conditions for such a controller are presented with LMI forms. Both sojourn times of jump

Parameters of the mathematical model describing many practical dynamical systems are prone to vary due to aging or renewal, wear and tear, as well as changes in environmental or service conditions. These variabilities will adversely affect the accuracy of state estimation. In this article, we introduce SSUE: simultaneous state and uncertainty estimation for quantifying parameter uncertainty while simultaneously

Bounded input delay frequently arises in discrete‐time linear systems. The standard predictor feedback design requires the exact knowledge of the delay. Such a requirement on the availability of the delay knowledge poses challenges in the design of robust control laws when only the knowledge of an upper bound of the delay is known. We propose such a design in this article. Based on the delay‐independent

This paper presents an algorithm that computes polytopic robust control‐invariant (RCI) sets for rationally parameter‐dependent systems with additive disturbances. By means of novel linear matrix inequalities (LMI) feasibility conditions for invariance along with a newly developed method for volume maximization, an iterative algorithm is proposed for the computation of RCI sets with maximized volumes

It is nontrivial to achieve adaptive asymptotic tracking control of multi‐input multi‐output (MIMO) nonlinear systems subject to asymmetric yet time‐varying output constraint and nonparametric uncertainties. The problem will become even challenging when the event‐triggered mechanism via controller‐to‐actuator channel is considered as it may impose additional design difficulty caused by the high‐order