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In this paper, the problem of fault estimation (FE) and fault‐tolerant control (FTC) for a class of systems with dynamic event‐triggered mechanism (ETM) and time delay in a network environment is studied. To shorten the time between events and minimize the amount of data transmitted, this paper introduces dynamic variables within the ETM. In order to ensure the interval between the system state and its estimation, a fault/state estimation observer considering time delay is designed, which improves the reliability and security of the system. On this basis, a fault‐tolerant controller considering time delay is constructed to compensate the impact of faults on the system. The observer, controller, and ETM are co‐designed to maintain system performance. By making full use of the information between subsystems, a continuous time interconnection systems is constructed and the cooperative control mechanism is redesigned on the basis of the above system. Through theoretical analysis, it has been demonstrated that Zeno phenomenon does not exist in the ETM in this paper. Finally, the main results are verified by numerical simulation, and the validity of the conclusions is demonstrated. [ABSTRACT FROM AUTHOR]

Summary: This paper deals with observer‐based fault estimation (FE) and proportional derivative state feedback fault tolerant control (FTC) schemes for singular systems affected by actuator fault, interval time‐varying delay and external disturbance. Firstly, the system transformation method of constructing the derivative matrix into a full‐rank matrix is adopted to transform the singular system into a normal system, which effectively eliminates the impulse characteristic of the singular system. Secondly, in the design of the dynamic observer, fault estimation utilizes the real‐time output error and its derivative simultaneously, which can achieve better estimation performance when the fault change frequently. Most importantly, the observer‐based FTC adopts a proportional derivative state feedback control, considers disturbance and interval time‐varying delay, and the introduction of state estimation derivative term can eliminate the impulse property of the closed‐loop system, which optimizes the design scheme of the fault‐tolerant controller. The obtained sufficient conditions for stability can be solved by the strict linear matrix inequality (LMI), and the superiority of the conclusions will be further verified by the simulations. [ABSTRACT FROM AUTHOR]

Summary: In this article, we study the problem of robust fault estimation for a class of T‐S fuzzy systems with time delays and external disturbances based on the finite information learning observer. The learning observer with intermittent sampling is constructed and the change rate of output estimation error is introduced to estimate the system fault effectively. At the same time, by introducing a generalized inverse matrix to the designed observer, a sufficient condition for the stability of the error estimation system is given by using fuzzy Lyapunov function, which not only solves the problem of system fault and external disturbance estimation, but also reduces the conservatism of the obtained conclusion. Finally, the results described by LMI are solved numerically and simulated to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Summary: In this paper, the problem of multi‐objective robust fault estimation based on observer is addressed for T‐S fuzzy nonlinear singularly perturbed systems with time‐varying state delay and external disturbance. Under H∞$$ {H}_{\infty } $$ performance constraint, a fuzzy augmented fault estimation observer is introduced to improve the performance of actuator and sensor fault estimation simultaneously. The sufficient conditions for the existence of fault estimator are given in the form of LMIs, where ε$$ \varepsilon $$‐dependent Lyapunov function is considered. The given multi‐objective fault estimator design strategy has a good ability to suppress external disturbance and ensure the estimation accuracy and convergence rate work well for all ε∈(0,ε‾]$$ \varepsilon \in \left(0,\overline{\varepsilon}\right] $$. Then the largest stability bound and the best attenuation capacity are guaranteed by deriving a modified optimal algorithm. Finally, two examples are given to illustrate the feasibility and correctness of the proposed design method. [ABSTRACT FROM AUTHOR]

This paper focuses on the output to state description-based convergent fault tolerant control (FTC) for a class of linear time invariant (LTI) systems. An output to state description theorem is proposed, by which, an adaptive output feedback FTC with a function equation constraint is designed for the LTI system in consideration. A controller reconfiguration algorithm is proposed to solve the constraint and construct an approximate controller that can compensate effectively the fault effect on systems. Furthermore, in certain conditions, the output feedback control gains can be determined by the state feedback control gains. A linear longitudinal dynamics of an aircraft and a linearised dynamic model of a vertical takeoff and landing (VTOL) aircraft in the vertical plane are applied to illustrate the effectiveness and merits of the proposed method. [ABSTRACT FROM AUTHOR]

A dual-channel solar thermal storage wall system with eutectic phase change material is studied. The full-day cooling load in summer and heating load in winter can be both decreased by this novel system. To investigate the airflow in the dual channel, mixed area assumptions based on the experimental results are summarized. Dynamic mathematical models of the system under four work modes are established and verified by the experimental results. The average RMSD (root mean square deviation) value is 0.35% in summer and 0.95% in winter. By analyzing the heat flux, the combination of dual channel and PCM is proven to decrease and delay cooling load both in the daytime and nighttime of summer. In winter's daytime, the thermal efficiency is promoted by the dual channel. And in winter's nighttime, the system is able to heat the room constantly by the PCM boards. Based on parameter researches, the optimum phase change temperature range and the optimum thickness of the PCM are 26–30 °C, 1.5 cm in summer and 16–22 °C, 0.6 cm in winter respectively. To reach the optimum annual thermal performance, the coverage area is 2 m2 for this system. [ABSTRACT FROM AUTHOR]

ABSTRACT This article studies the problem of fault estimation (FE) and dynamic output fault‐tolerant control (DOFTC) for a class of Takagi–Sugeno (T–S) fuzzy singularly perturbed systems (SPSs) which subject to time delay, external disturbance and actuator fault. A new fault estimation and fault‐tolerant control scheme was proposed and designed for the influence of the change of perturbation parameter ε$$ \varepsilon $$ on the singularly perturbed system. This scheme adopts the Takagi–Sugeno (T–S) fuzzy model, learning observer and dynamic output feedback fault‐tolerant mechanism, so that the system has multi‐time‐scale dynamic stability. The results show that this method has more accurate estimation effect, faster convergence speed, and very fast steady‐state response of fault‐tolerant control when faults occur. Furthermore, when constructing the Lyapunov function, the improved matrix P(ε)$$ P\left(\varepsilon \right) $$ was selected to ensure that the closed‐loop system is stable for all ε∈(0,ε‾]$$ \varepsilon \in \left(0,\overline{\varepsilon}\right] $$, and at the same time, the conservativeness of the results was reduced. Finally, the feasibility and correctness of the proposed design method were illustrated through two numerical examples. [ABSTRACT FROM AUTHOR]