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This paper mainly focuses on the cooperative robust consensus tracking problem of uncertain networked Euler-Lagrange systems (NELSs) with time-varying delays and output constraints. By systematically integrating the neural network (NN) adaptive technique and the logarithmic type Barrier Lyapunov Function (BLF) in combination with the additional robust control law, two distributed robust consensus schemes for uncertain NELSs are proposed for two cases of time-varying communication and input delays respectively, which can fully guarantee to constrain the output consensus error within a safety region simultaneously. Furthermore, numerical simulation examples are provided to demonstrate the comparable potential advantages of the proposed robust control law over some existing algorithms, including adaptability, stability, and robustness, as well as delay effects. • An NN-based robust controller is designed to effectively handle the uncertainty of NELSs. • Combining NN with BLF ensures the adaptability, stability, and robustness of the consensus tracking scheme for NELSs. • A unified analytical framework is developed by deriving upper bounds on the allowed values of communication and input delays. [ABSTRACT FROM AUTHOR]

This paper investigates the fault-tolerant tracking control issue for a class of discrete-time systems with sensor fault. A novel model-free adaptive fault-tolerant tracking control scheme is proposed by utilizing the dynamic linearization approach, in which only input/output (I/O) data of controlled plant are required. Moreover, due to the characteristics of simple structure and powerful approximation ability, RBF neural network (RBFNN) is introduced to approximate the fault dynamics after the sensor fault is detected. The approximated fault dynamic is utilized to reconstruct the controller. The major feature of this paper is that the whole fault-tolerant tracking controller structure is derived from the dynamic linearization of the ideal controller, rather than the criterion function. Finally, the proposed model-free adaptive fault-tolerant tracking controller is verified to be effective by numerical simulations. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the cooperative output regulation problem for a class of heterogeneous linear multi-agent systems under undirected communication topological graph. First, an adaptive event-triggered protocol is introduced to achieve the consensus problem for leader-following system. Then, two fully distributed event-triggered adaptive control protocols are designed. That is, the state feedback and dynamic output feedback controllers, which does not need global information about network topology of system. Under the proposed two control protocols, the cooperative output regulation problem can be solved and no Zeno behavior happens for each agent. Finally, a numerical simulation is used to corroborate the validity of the conclusions under two control laws. Moreover, a comparative experiment is carried out to highlight the advantages of the control protocol designed in this paper. [ABSTRACT FROM AUTHOR]

This paper studies a challenging issue introduced in a recent survey, namely designing a distributed event-based scheme to solve the dynamic average consensus (DAC) problem. First, a robust adaptive distributed event-based DAC algorithm is designed without imposing specific initialization criteria to perform estimation task under intermittent communication. Second, a novel adaptive distributed dynamic event-triggered mechanism is proposed to determine the triggering time when neighboring agents broadcast information to each other. Compared to the existing event-triggered mechanisms, the novelty of the proposed dynamic event-triggered mechanism lies in that it guarantees the existence of a positive and uniform minimum inter-event interval without sacrificing any accuracy of the estimation, which is much more practical than only ensuring the exclusion of the Zeno behavior or the boundedness of the estimation error. Third, a composite adaptive law is developed to update the adaptive gain employed in the distributed event-based DAC algorithm and dynamic event-triggered mechanism. Using the composite adaptive update law, the distributed event-based solution proposed in our work is implemented without requiring any global information. Finally, numerical simulations are provided to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

This paper investigates the control issue of the noncooperative spacecraft proximity with prescribed performance by exploiting only relative motion information. To accommodate the direct use of relative measurement, the 6-degree-of-freedom (6DOF) relative dynamics is formulated in the body frame of the pursuer. Based on the smooth Gauss error function, a new asymmetric saturation function is developed to satisfy the practical control limitations. To maintain the relative attitude and position within specified constrained ranges, a novel performance function in possession of the preassigned settling time and convergence set of steady state error is proposed. Based on the backstepping framework, the relative attitude and position controllers are surveyed in sequence. In particular, a state constrained virtual control is first developed for each relative dynamics by introducing a nonlinear transformation. Then a neuroadaptive saturated control law is designed by implementing a Nussbaum function based adaptive control coefficient. Stability analysis indicates that the closed-loop 6DOF relative dynamics are asymptotically stable with prescribed performance. Numerical simulations further verify the proposed control strategy. • A control strategy is developed by using only relative motion information. • A novel performance function with accurate and intuitive settling time is proposed. • An asymmetric saturation function is designed to satisfy the control constraints. • A neuroadaptive algorithm is introduced to ensure the high control accuracy. [ABSTRACT FROM AUTHOR]

This paper proposes a novel finite-time integrated guidance and control (IGC) design for skid-to-turn (STT) missiles, taking full state constraints into account. Firstly, the actuator saturation is converted into a state constraint. Secondly, to handle full state constraints effectively, the "non-constrained" IGC (NCIGC) model is constructed by combining the IGC model with a permissible set of states and applying a nonlinear transformed function. Thirdly, a finite-time full state constraints IGC scheme based on the NCIGC model is presented. According to Lyapunov stability theory, the proposed IGC method is verified to ensure that all states of the IGC model converge to a small neighborhood near zero within a finite time while satisfying the predefined state constraints. Finally, numerical simulations are performed to demonstrate the effectiveness and robustness of the proposed IGC scheme. [ABSTRACT FROM AUTHOR]

This paper researches the adaptive bipartite output containment problem, for a signed graph of heterogeneous multi-agent systems (HMASs). The dynamics of leaders are subject to unknown but bounded inputs, which cannot be measured by followers. Therefore, an containment control protocol based on distributed observer is proposed. An adaptive state and an output feedback algorithm are designed to ensure that cooperative and antagonistic agents enter different convex hull. Then, based on the output regulation approach, Lyapunov stability analysis and some other methods, the bipartite output containment control is realized. Finally, we validate the analytical results by numerical simulations. [ABSTRACT FROM AUTHOR]

This paper studies distributed time-varying formation control problems for a class of linear systems with heterogeneous uncertainties and directed graphs. Both the cases without and with an active leader having unknown control inputs are considered. Two new robust adaptive formation protocols are designed in a totally distributed fashion, both of which incorporate two parts: a fully distributed nominal controller relying on the neighbors' relative state information and an adaptive compensating signal to restrain the influences of uncertainties. An original adaptive compensating strategy is proposed herein to deal with uncertainties related to not only system states but also control inputs. On the basis of adaptive mechanism, the controller design requires neither global information about communication topologies nor the upper bounds of uncertainties and the leader's control inputs. Based on Lyapunov arguments, sufficient conditions to achieve the desired formation are derived in terms of Riccati equations. The proposed protocols guarantee that the formation errors can converge to zero. Finally, the theoretical results are demonstrated by numerical simulations. [ABSTRACT FROM AUTHOR]

This paper investigates the practical fixed-time consensus problem for a multi-agent system in networks with an undirected topology. Both node-based and edge-based fully distributed adaptive protocols are proposed to achieve the practical fixed-time consensus for the single integrator-type multi-agent systems, i.e., fixed-time attractiveness of a residual set as well as asymptotic consensus. Most notably, the settling time estimate can be computed without using any global information, which is distinctive from the existing fixed-time protocols. Furthermore, a scaling technique is applied for the proposed protocol such that the fixed-time attraction region can be contracted by only tuning a scaling parameter and the original settling time estimate remains unchanged. Finally, a numerical simulation example is given to validate the proposed protocols. [ABSTRACT FROM AUTHOR]

This paper presents a distributed swarm system for small fixed-wing unmanned aerial vehicles (UAVs). In particular, to perform various missions with multiple UAVs that are densely gathered and collision free, a hybrid-flocking control algorithm is synthesized by using three types of control protocols: vector field guidance (for path following/loitering), augmented Cucker–Smale (ACS) model (for collective flocking behavior), and potential field (for collision avoidance). In particular, to address the issue of conflicts between different control protocols, the adaptive ACS model is proposed and the optimization problem is formulated to determine the suitable mixing weights of control protocols. We also design the transition of multiple operation modes and communication architecture for the swarm system. The system is evaluated using the proposed hybrid-flocking control algorithm by proof-of-concept real flight experiments using 18 small fixed-wing UAVs as well as extensive numerical simulations. Flight experiments are successfully performed for multiple consecutive tasks including the individual task, circular path loitering and elliptical path loitering while avoiding collisions among UAVs. • The distributed small fixed-wing UAV swarm system is designed. • The hybrid-flocking control algorithm is proposed by combining three control protocols. • The optimal mixing weight improves the mission performance. • Numerical simulations and flight experiments validate the hybrid-flocking algorithm. [ABSTRACT FROM AUTHOR]

In this paper, we proposed an iterative learning control (ILC) update rule to synchronize an array of non-identical time-varying delayed neural network systems in a repetitive environment. Under the identical initial conditions, we employed a distributed D -type ILC update rule that guaranteed synchronization by choosing the appropriate inner coupling matrix. Besides, to accommodate non-identical initial conditions, we proposed another adaptive ILC update rule that also could synchronize the systems. Two numerical simulations are presented to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

This paper proposes an adaptive control scheme for hypersonic vehicle with external disturbances, parametric uncertainties, actuator failures, input saturation and state constraints. Firstly, the longitudinal model of generic hypersonic vehicle is divided into velocity subsystem and altitude subsystem. Secondly, based on the tangent barrier Lyapunov function and auxiliary system, two adaptive fault tolerant controllers are designed for velocity subsystem and altitude subsystem, respectively, which can solve the problem of input saturation. By using the controllers, the flight states containing the angle of attack, flight path angle, pitch angle and pitch angle rate can be guaranteed in prospective ranges. Finally, the Lyapunov stability theory and numerical simulations are adopted to verify the effectiveness of the presented controllers. • The prescribed tracking performances are guaranteed. • State constraints of the system are guaranteed. • The input saturation and external disturbance are solved. [ABSTRACT FROM AUTHOR]

This paper is devoted to investigating the anti-swing control problem for a suspension cable system of a helicopter with cable swing constraint and unknown dead-zone. Barrier Lyapunov function is adopted to guarantee that cable swing constraint will not be violated and dead-zone problem is considered as a special bounded disturbance to tackle in the processing of adaptive controller design. Under the proposed control law, the uniform ultimately boundedness of closed-loop system is analyzed. Meanwhile, the vibration range will converge to a small neighborhood of zero by choosing suitable design parameters in spite of considering cable swing constraint and unknown dead-zone. The performances of the designed adaptive boundary control scheme are verified by a numerical simulation. [ABSTRACT FROM AUTHOR]

This paper explores the prescribed-time stabilization problem of strict-feedback uncertain systems, which is quite challenging when unknown control gain (both amplitude and direction) and mismatched nonparametric uncertainties are involved. This paper is the first to address prescribed-time control of such uncertain systems. To overcome the main obstacles of mismatched nonparametric uncertainties and unknown control gain, we extract some structural information of the uncertain systems and blend Nussbaum function into prescribed-time controller. When designing the controller by backstepping method, we perform descending power time-varying scaling on system states, converting the prescribed-time stabilization problem into boundedness problem of the new variables. Unlike most existing works on prescribed-time stabilization, we make use of the special property of Nussbaum function to guarantee the boundedness of the new variables. It is shown that the settling time is user-assignable a priori regardless of the initial condition. The effectiveness of the proposed method is validated via numerical simulations. [ABSTRACT FROM AUTHOR]

In this paper, we apply the technique of non-constant delay control to a problem of velocity stabilization for a system whose domain is time-varying. This system is modeled as a wave PDE on a domain with a moving boundary. The problem is transformed first into an LTI form describing the boundary dynamics. A time-varying input delay and unknown parameters characterize this uncertain linear system. From there, we use the backstepping design via a transport PDE to construct an adaptive boundary controller. The boundary states are assumed to be the only measurements available for feedback. The stability analysis is given for the closed-loop system, and the boundedness of the state is proven. The paper concludes with a numerical simulation illustrating and contrasting the performance of the derived controller. [ABSTRACT FROM AUTHOR]

Abstract Hovering over an irregular-shaped asteroid is particularly challenging due to the large gravitational uncertainties and various external disturbances. An adaptive control scheme considering commanded acceleration and its change-rate saturation for hovering is developed in this paper. Taking full advantage of terminal sliding-mode control theory, first, we convert the double-saturated control problem to a new equivalent system by introducing a special bounded function, in which just control input saturation needs to be considered. Then, a continuous finite-time saturated controller is designed for the new system with the assistance of an constructed auxiliary subsystem. Additionally, an adaptive law is devised for the controller to avoid the requirement of the unknown upper bounds of the disturbances, rendering the control scheme especially suitable to asteroid hovering missions. The finite-time stability of the whole closed-loop system is proved via Lyapunov analysis. Numerical simulation studies are carried out, and the results demonstrate the design features and the desired performance. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the adaptive consensus problem of multi-agent nonlinear systems with odd impulsive sequence. To reduce the required information transmitted among the nodes, the distributed impulsive control protocol is designed. Considering the unknown system parameters in real system, the adaptive control technique is also used and some novel sufficient consensus conditions are derived to achieve the consensus of multi-agent nonlinear systems. The proposed odd impulsive control can obtain larger control region than the common impulsive consensus method with fixed impulsive instants, which is more flexible and reliable in practical application. Finally, two simulations are given to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

Highlights • Fractional-order calculus is proposed to yield more performing ACC/CACC gap control. • The control design relies in multi-objective optimization seeking a Pareto front. • String stability is further improved for lower time gaps maintaining robustness. • Comparison with state-of-the-art approaches is included, showing its benefits. • The comparison and validation section has been reorganized. Abstract Traffic flow optimization and driver comfort enhancement are the main contributions of an Adaptive Cruise Control (ACC) system. If communication links are added, more safety and shorter gaps can be reached performing a Cooperative-ACC (CACC). Although shortening the inter-vehicular distances directly improves traffic flow, it can cause string unstable behavior. This paper presents fractional-order-based control algorithms to enhance the car-following and string stability performance for both ACC and CACC vehicle strings, including communication temporal delay effects. The proposed controller is compared with state-of-the-art implementations, exhibiting better performance. Simulation and real experiments have been conducted for validating the approach. [ABSTRACT FROM AUTHOR]

This paper presents an aerodynamic model-based robust adaptive control algorithm for close formation flight. The leader aircraft is assumed to be at level and straight flight which characterizes the most common scenario for close formation flight. The formation aerodynamic effects are assumed to be unknown, but an online formation aerodynamic model is available to predict those effects. In light of the online formation aerodynamic model, a robust adaptive control algorithm is thereafter developed on the follower aircraft to counteract the unknown formation aerodynamic effects and obtain highly accurate formation tracking performance. The proposed control algorithm is composed of a baseline controller and an integrator-augmented robust adaptive controller, which can efficiently deal with both matched and mismatched formation aerodynamic effects and external disturbances. The major advantage of the proposed design is that it can achieve at least ultimate bounded tracking control with certain transient performance guaranty. The efficiency and robustness of the proposed control design are eventually validated via numerical simulations of close formation flight at two different scenarios. [ABSTRACT FROM AUTHOR]

In this paper, a novel adaptive neural control methodology is addressed for a flexible air-breathing hypersonic vehicle (FAHV) by a fusion of improved back-stepping and a minimal-learning-parameter (MLP) scheme. To facilitate the control design, the vehicle dynamics is decomposed into the altitude subsystem and the velocity subsystem. Different from the traditional back-stepping design, in this paper, the virtual control laws for the altitude dynamics are artificial intermediate variables required only for analytic purpose while only the final actual controller is needed to be implemented. For each subsystem, only one neural network is employed to approximate the lumped uncertainty. Moreover, by the merit of the MLP technique, only one learning parameter is required for neural approximation in each subsystem. The novel contribution with respect to the existing literatures is that the proposed control strategy is concise and the computational load is low. Finally, the effectiveness of the exploited control approach is verified by simulation results in the presence of uncertain parameters. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the cluster synchronization problem of complex networks via pinning control. Nodes in the same cluster are governed by the same dynamical function, while the functions for different clusters are different. For the coupling scheme, the effects of the coupling are assumed to be only cooperative, i.e., the coupling matrix is a Metzler matrix with zero row sums, and the connections between the same cluster can be few. For this type of coupling, the main difference of this paper with previous works is that the cluster synchronization is realized by pinning control technique. A simple pinning control strategy is proposed and some sufficient criteria to realize cluster synchronization with both static and adaptive control strength are given. Finally, numerical simulations are presented to verify our theoretical results. [ABSTRACT FROM AUTHOR]

This paper deals with the synchronization for Arneodo chaotic system and response system with unknown nonlinear function. Based on backstepping method, a fuzzy adaptive control scheme by combining fuzzy logic system with parameter is presented to achieve synchronization. Contrasting to fuzzy adaptive controller in the previous literature, the number of adaptive laws reduced greatly by using the proposed controller in this paper. Numerical simulation has been validated the backstepping design and analysis. [ABSTRACT FROM AUTHOR]

This paper focuses on the Mars soft pinpoint landing feedback guidance to construct a non-concave trajectory for superior obstacle avoidance and camera's field of view of the landing site. More specifically, to steer the vehicle to satisfy the non-concave trajectory, an adaptive curvature guidance is developed based on a nominal curvature dynamic model. Then, an adaptive sliding mode guidance based on zero-effort-miss/zero-effort-velocity (ZEM/ZEV) guidance is proposed, which not only maintains the advantages of ZEM/ZEV guidance but also improves the robustness. Furthermore, numerical simulations are performed to verify the feasibility and effectiveness of the proposed algorithms. Moreover, by constructing a glide-slope trajectory, the terminal lateral accelerations are zeros, which can effectively avoid rollover when the vehicle touches the Mars surface. [ABSTRACT FROM AUTHOR]

During drilling the mud flows through the drill string and exits through the choke valve. The mud density range has as constraints: pore pressure (minimum limit) and fracture pressure (maximum limit). In fact, annulus bottomhole (downhole) pressure needs to be higher than pore pressure, in order to prevent kick, and smaller than fracture pressure, for avoiding mud loss and formation damage. Experimental and simulation studies were implemented in order build a monitoring – diagnosing tool working together with a decision making routine based on an adaptive control scheme that employs gain scheduling. An experimental unit was built, presenting the most important characteristics of the drilling process. The transient nature of annulus bottomhole pressure is due to the process inherent disturbances: rheology, rate of penetration (ROP), kick and mud loss, which were all implemented at the experimental unit. The major objective of the present paper is using the experimental plant and a phenomenological model for implementing real time process automation, in order to assure drilling inside operational window, using in line measurements for flow and density disturbances under circulation loss and kick scenarios. [ABSTRACT FROM AUTHOR]

This paper focuses on estimation and cancellation of unknown sinusoidal disturbances in a known LTI system with the presence of a known output delay. Parametrizing the disturbance and representing the delay as a transport PDE, the problem is converted to an adaptive control problem for ODE–PDE cascade. An existing state observer is used to estimate the ODE system states. The exponential stability of the equilibrium of the closed-loop and error system is proved. The perfect estimation of the disturbance and state is shown. Moreover, the convergence of the state to zero as t → ∞ is achieved in the closed loop system. The effectiveness of the controller is demonstrated in a numerical simulation. [ABSTRACT FROM AUTHOR]

This paper is concerned with a kind of mixed adaptive control architecture for a novel tandem coaxial-ducted-fan aircraft in the presence of relative large time-vary uncertainties and external disturbances. For the proposed aircraft, elementary analysis is first performed to evaluate the system's inherent sensitivity to uncertainty. The control architecture includes mainly two parts: a robust decoupling controller and a L1 adaptive augmentation. The robust decoupling controller designed via H-infinity synthesis mainly provides states decoupling and ensures baseline performance; while the L1 adaptive augmentation based on L1 adaptive theory is mainly responsible for large uncertainty estimation and compensation. Numerical simulations of this novel unmanned aerial vehicle (UAV) are applied to illustrate the performances of the proposed control architecture. The simulation results reveal that compared to the classic robust method, the proposed controller is more effective and shows much improvement even under relative serious uncertainties and external disturbances. [ABSTRACT FROM AUTHOR]

In this paper, we propose two adaptive control schemes to solve the output tracking control problem of a class of uncertain switched nonlinear systems. The first is a robust scheme constructed based on common Lyapunov function method, aiming to achieve the insensitivity of closed-loop system to parameter switches by estimating the bound on switching parameters. It is analyzed that the system stability under arbitrary switching is established with such a scheme, but the control input required may be relatively large since the estimate of the bound on switching parameters is utilized. To avoid this, we further propose a direct adaptive control scheme by estimating the switching parameters directly, and derive a dwell-time condition for parameter switches based on an extended multiple Lyapunov functions method newly developed, such that the global boundedness of all the closed-loop signals and the convergence of tracking error to a residual around zero are ensured. The effectiveness of the proposed control schemes is illustrated through simulation studies. [ABSTRACT FROM AUTHOR]

This paper presents a distributed adaptive control framework for multiple spacecraft formation flying around Lagrange point orbits, which account for unmeasurable velocities and (spacecraft) mass uncertainties. The nominal trajectory for the formation system is a halo orbit parameterized by Fourier series expansions. Such an explicit, albeit approximate, description of the nominal trajectory facilitates each spacecraft in formation to include the relative state information into a cooperative feedback control system design, so that the relative motion can be driven towards a desired trajectory while maintaining a group synchronization during the maneuver. The developed distributed control strategies rely on the protocols formulated on an undirected topology with mutual information interactions, utilizing every available neighbor-to-neighbor communication data couplings, in order to improve the reliability of the formation. Numerical simulations show that the proposed adaptive control laws guarantee global asymptotic convergence and system robustness. [ABSTRACT FROM AUTHOR]

This paper presents a backstepping procedure to design an adaptive controller for the air-breathing hypersonic flight vehicle (AHFV) subject to external disturbances and actuator saturations. In each step, a sliding mode exact disturbance observer (SMEDO) is exploited to exactly estimate the lumped disturbance in finite time. Specific dynamics are introduced to handle the possible actuator saturations. Based on SMEDO and introduced dynamics, an adaptive control law is designed, along with the consideration on “explosion of complexity” in backstepping design. The developed controller is equipped with fast disturbance rejection and great capability to accommodate the saturated actuators, which also lead to a wider application scope. A simulation study is provided to show the effectiveness and superiority of the proposed controller. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the distributed adaptive leader-following consensus control for high-order nonlinear multi-agent systems with time-varying reference trajectory under directed topology subjected to mismatched unknown parameters and uncertain external disturbances. By introducing local estimators for the bounds of reference trajectory and a filter for each agent, a new backstepping based smooth distributed adaptive control protocol is proposed. It is shown that global uniform boundedness of all the closed-loop signals and asymptotically output consensus tracking can be achieved. Simulation results are provided to verify the effectiveness of our scheme. [ABSTRACT FROM AUTHOR]

In this paper, an identifier–critic structure is introduced to find an online near-optimal controller for continuous-time nonaffine nonlinear systems having saturated control signal. By employing two Neural Networks (NNs), the solution of Hamilton–Jacobi–Bellman (HJB) equation associated with the cost function is derived without requiring a priori knowledge about system dynamics. Weights of the identifier and critic NNs are tuned online and simultaneously such that unknown terms are approximated accurately and the control signal is kept between the saturation bounds. The convergence of NNs’ weights, identification error, and system states is guaranteed using Lyapunov’s direct method. Finally, simulation results are performed on two nonlinear systems to confirm the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

This paper presents a novel adaptive dynamic sliding mode scheme for the deployment of the tethered satellite system. To overcome the limited inputs of the dynamic model, a new scalable dimensionless transformation and strictly bounded terms are designed, which guarantee the existence of the ratio between limited inputs and command signals. The adaptive saturated sliding mode control scheme is proposed to govern the tether deployment by introducing the adaptive rate into the system gain. The stability analysis indicates that this measure can eliminate the uncertainty caused by the input limitation and guarantee the asymptotically stability of the deployment dynamics. Finally, numerical simulations are presented to verify the effectiveness of the proposed control laws. [ABSTRACT FROM AUTHOR]

The first step in subspace methods for identification of multivariable systems is the estimation of the order of the model to be identified. Model order estimation is especially difficult for ill-conditioned systems. In previous work we showed heuristically that appropriately designed experiments with rotated PRBS inputs greatly facilitate model order estimation, hence overall model accuracy. However, design of such experiments depends on the very system to be identified. To overcome that difficulty, in this paper we propose an adaptive design of experiments. The proposed approach follows rigorous justification of the need for rotated PRBS inputs, and is tested through computer simulations on two case studies involving a high-purity distillation column and a fluidized catalytic cracking unit. Comparisons of the approach to open- and closed-loop alternatives are presented, and suggestions for further development are made. [ABSTRACT FROM AUTHOR]

This paper addresses the controller design problem for global fixed-time synchronization of delayed neural networks (DNNs) with discontinuous activations. To solve this problem, adaptive control and state feedback control laws are designed. Then based on the two controllers and two lemmas, the error system is proved to be globally asymptotically stable and even fixed-time stable. Moreover, some sufficient and easy checked conditions are derived to guarantee the global synchronization of drive and response systems in fixed time. It is noted that the settling time functional for fixed-time synchronization is independent on initial conditions. Our fixed-time synchronization results contain the finite-time results as the special cases by choosing different values of the two controllers. Finally, theoretical results are supported by numerical simulations. [ABSTRACT FROM AUTHOR]

This paper is concerned with the pinning adaptive synchronization control problem for a class of complex networks of networks. The complex networks of networks under consideration are composed of both leaders' network and followers' networks (also called “subnetworks”), where the leaders' network and subnetworks are regarded as the nodes of the networks of networks, each subnetwork can receive the information from leaders' network, but not the reverse. In order to achieve the synchronization for the networks of networks, pinning control strategy is adopted, and adaptive controllers are designed for the controlled nodes. By utilizing the stability theory of dynamical systems and some analysis techniques such as the Barbalat lemma, several sufficient criteria are obtained to ensure global exponential synchronization for the controlled complex networks of networks. Finally, a numerical simulation example is given to verify the theoretical results. [ABSTRACT FROM AUTHOR]

This paper is devoted to adaptive synchronization and anti-synchronization between the TSUCS and the Lü, two unified chaotic systems. It is assumed that the parameters of the both systems are unknown. A designed controller based on Lyapanov candidate theorem is introduced for adaptive synchronization/anti-synchronization of two different unified chaotic systems and is used for adjusting estimation parameters until the measurable errors converge to zero. The stability evaluation and convergence analysis is carried out by Lyapanov stability theorem. Finally, some numerical simulations are presented to assess the behavior of the synchronization procedure and to verify the effectiveness of the theoretical analysis. [ABSTRACT FROM AUTHOR]

In this paper, an aperiodically adaptive intermittent control scheme combined with pinning strategy is proposed for outer synchronization between two general complex delayed dynamical networks. Through constructing a novel piecewise auxiliary function, some sufficient conditions for outer synchronization are derived based on the reduction to absurdity and piecewise analytic method. Different from the periodically intermittent pinning control, here the adaptive intermittent pinning control can be aperiodic. Additionally, an effective pinned-node selection scheme is provided to guide what kinds of nodes should be pinned first. Numerical simulations are finally given to illustrate the effectiveness of the obtained theoretical results. [ABSTRACT FROM AUTHOR]