Asian Journal of Control最新文献

This paper focuses on fault-tolerant control (FTC) for unmanned marine vehicles (UMVs) subject to unknown parametric dynamics, thruster faults, and external disturbances. A novel FTC strategy based on the integral sliding mode output feedback method is proposed. Based on a high gain compensator and output information, a novel integral sliding mode fault-tolerant controller is constructed to guarantee the dynamic positioning (DP) of UMVs. An attraction region that is related to the known positive constants with respect to dynamic uncertainties has been revealed for the first time. Finally, the closed-loop stability can be guaranteed from the every initial time in despite of unknown parametric dynamics, thruster faults, and external disturbances. Simulation though a typical floating production ship model has verified the effectiveness of the proposed method.

This paper studies the recursive fusion estimation issue for a class of linear time-varying multi-sensor systems with amplify-and-forward (AF) relays. The AF relay is located between the sensor and the estimator to forward measurement signals for facilitating long-distance transmission. A binary encoding scheme is used to regulate signal transmission via a digital network where the signal is encoded into a bit string and decoded at the endpoint of the receiver. Because of the uncertainty of the network and the existence of channel noises, a set of Bernoulli distributed random variables is introduced to characterize the random bit flip phenomenon. The purpose of the addressed problem is to design a fusion estimator to simultaneously reflect the impact of multiplicative noises, the AF relay, the binary encoding scheme, and the random bit flip on the filtering error covariance. First of all, an upper bound for the filtering error covariance of the local estimator can be acquired, and by minimizing such an upper bound, the parametric form of the gain matrix is obtained. Subsequently, the fusion estimation is given based on the covariance intersection fusion strategy. Finally, a simulation example is presented to verify the effectiveness of the proposed multi-sensor fusion estimation.

This article proposes an observer-based spatiotemporal event-triggered fuzzy resilient controller design method for the temperature profile across the fin of high-speed spacecraft. Initially, the considered nonlinear system is reconstructed via the Takagi–Sugeno fuzzy rule. Then, to simultaneously realize the observation and control of the spacecraft surface temperature, an observer-based point controller is proposed in terms of averaged measurements. In addition, taking the network congestion issue into consideration, a spatiotemporal event-triggered mechanism and a quantization method are adopted to reduce data transmission and enhance bandwidth utilization. Furthermore, to resist cyberattacks and actuator faults, a fuzzy resilient control strategy is designed to ensure the stability of the closed-loop system with $��{�\mathscr{H}�}_{�\infty �}�$ disturbance attenuation performance. Finally, simulation results for a cooling fin are presented to demonstrate the validity of the proposed method.

This paper copes with the fixed-time fault-tolerant control problem for a single-machine infinite power system with static VAR compensators. In order to handle the controller design problem caused by the actuator failures and unknown dead zone input, a fuzzy fault-tolerant control algorithm is derived by introducing the adaptive backstepping method. An adaptive fixed-time control strategy is designed to guarantee that the output signal can track the desired trajectory within a fixed time, where the convergence time is independent of the initial condition. Compared with existing results, the proposed controller guarantees the controlled system maintains semiglobal fixed-time stability and the tracking error converges to a small neighborhood around zero. Both actuator faults and dead zones have been considered, which can better meet the practical control requirements. A simulation example demonstrates the designed controller.

This paper proposes an adaptive safety control method applicable to a multiplayer mixed zero-sum (MZS) game of nonlinear systems with partial inputs delay. Firstly, a framework is introduced involving N players, where player 1 and player N form a zero-sum (ZS) game, and player 1 and players 2 to N-1 form nonzero-sum (NZS) games, with some players experiencing time delays. Subsequently, the system's value function is augmented with a control barrier function (CBF) to ensure that the system's state remains within a safe region. Secondly, to approximate Nash equilibrium solutions, the study employs adaptive dynamic programming (ADP) and utilizes a critic-only neural network (NN) to approximate optimal solutions. Diverging from traditional time-trigger methods, computational and communication load reduction is achieved by introducing a state-related event trigger condition. The stability of the system is then meticulously analyzed using the Lyapunov theorem. Finally, to validate the effectiveness of the proposed method, the study provides a simulation example demonstrating its performance. In summary, this research introduces an efficient adaptive safety control method for addressing multiplayer MZS games with partial inputs delay, incorporating CBFs, ADP, and state-related event triggering.

This paper investigates the finite-time output voltage tracking control problem of energy storage inverters. Multiple load conditions are simultaneously considered. To complete the tracking control task and enhance the power quality under different loads, a composite control scheme, which contains two parts, is proposed. In the first part, two finite-time disturbance observers are established to estimate the mismatched multiple disturbances originating from load variations. In the second part, new integral-type sliding-mode surfaces embedding disturbance estimates and $��d�q�$-axis couplings are designed, which not only feedforward compensate for the disturbances but also achieve decoupling. Based on the sliding-mode surfaces, a composite controller is constructed. Compared with the existing results, the proposed controller is continuous and significantly reduces chattering. Moreover, with the novel decoupling strategy, the $��d�q�$-axis coupling problem is solved precisely without generalizing the couplings as disturbances, which simplifies the observation task and further accelerates system convergence. Rigorous stability analysis is conducted to demonstrate the accomplishment of the finite-time tracking task. Simulations and experiments are presented to validate the effects of the proposed control scheme.

This article examines the construction of the tracking control as well as the disturbance attenuation for a class of neutral descriptor semi-Markovian jump systems involving input time delays. On the basis of Matausek–Micic modified Smith prediction technique, a modified equivalent-input-disturbance and multiperiodic modified repetitive controller has been developed for obtaining the required results. In order to reject external disturbances actively, the modified equivalent-input-disturbance technique is utilized. To be more explicit, the modification of the Smith predictor block and integration of the transfer function provide accurate estimate, efficient attenuation of external disturbance and proper compensation for input time delays. While constructing the controller gain matrices, the specified matrix inequalities are solved concurrently. At last, the potential and applicability of the framed control law are illustrated through the simulated findings.

The time-varying output group formation-containment tracking (TVOGFCT) problem of discrete-time heterogeneous multi-agent system (MAS) is investigated in this paper. Assuming the MAS consists of multiple tracking leaders, formation leaders, and followers, and all the agents are divided into several groups. Firstly, to estimate the convex combination of tracking leaders in the same group, the distributed observers are designed for the formation leaders, and the observer-based formation tracking protocols are also presented to make formation leaders realize the desired time-varying group formation while tracking the convex combination of tracking leaders. Then, two types of observers are proposed to estimate the convex combination of tracking information and formation functions, based on which the containment tracking protocols are designed for the followers of each group. By using output regulation theory and Lyapunov theory, it is illustrated that the designed protocols can make the MAS realize TVOGFCT. Finally, the simulation results prove the correctness of the theoretical analysis.

In this paper, a fault identification strategy for nonlinear systems is proposed by combining the deterministic learning (DL)-based adaptive high-gain observer (AHGO) with a dynamic event-triggered mechanism (DETM). The DL theory is utilized to satisfy the partial persistent excitation condition, while the AHGO is employed to estimate the system states and fault functions simultaneously. Two DETMs are adopted to reduce data transmission and computational burden. The inter-event intervals of the considered event-triggered mechanisms are proven to be positive, thus excluding the Zeno phenomenon. The novelty of this paper lies in that, through the special design of AHGO and event-triggered conditions, the estimation errors can converge to zero with arbitrary precision. Meanwhile, by incorporating the estimated output error into the DETM design, it is demonstrated that the number of events can be adaptively adjusted based on the fault signal. Furthermore, the relationship between the observer gain and system performance, as well as the inter-event interval, is revealed (The event-triggered mechanisms design method that ensures exponential convergence of the observer). Finally, the effectiveness of the developed strategy is verified through a simulation example.

The issue of fault detection and isolation design in the finite-frequency domain for discrete-time Lipschitz nonlinear systems subjected to actuator faults and disturbances is investigated. A bank of H₋/L_∞ unknown input observers (UIOs) is established using the generalized observer scheme to generate residuals that are insensitive to a specific actuator fault but sensitive to the other actuator faults. Furthermore, in the finite-frequency domain, the H₋ and L_∞ performance indices are simultaneously used to improve the fault detection sensitivity and attenuate the influence of disturbances on the residuals, respectively. The design conditions for the bank of H₋/L_∞ UIOs are derived from the generalized Kalman–Yakubovich–Popov lemma and converted into an optimization problem constrained by linear matrix inequalities to solve the design matrices more easily. To diagnose actuator faults, a fault detection and isolation scheme is established using the time-varying threshold from the L_∞ performance analysis. Finally, the effectiveness of the fault detection and isolation scheme using the bank of H₋/L_∞ UIOs is validated by the simulation of two examples.