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Frequency splitting, a phenomenon causing transfer efficiency decreasing in wireless power transfer (WPT) systems when the coupling strength is too strong, can be suppressed by combining the magnetic and the electric couplings with out-of-phase polarities to constitute a hybrid WPT (HWPT) structure. In this article, the exact critical coupling coefficient of the HWPT structure is obtained from the ridge equation of the analytical efficiency expression. It is found to approximate 1/ $Q$ ( $Q$ is the loaded quality factor of the resonators), which shows a similar property with the conventional inductively coupled WPT (IPT) system. In order to improve the efficiency after the critical coupling distance, the magnetic coupling only or the in-phase structures are proposed and realized by rotating the transmitter and adjusting the values of the electric coupling. In addition, for the applications requiring high efficiency over a long transfer distance, a design procedure of the resonator is given with the help of the analytical relationships between the electric parameters and geometrical parameters of the coupling structures. The electromagnetic simulations (ANSYS HFSS) and experiments show good agreement with the theory. The efficiency can hold above 70% within 40–260-mm transfer distance. Compared with the existing HWPT system, the operating distance range is extended from 130 to 220 mm, featuring an $\sim $ 69% improvement.

Nonferromagnetic metal materials are widely used in industry. Defects generated during manufacture and use may lead to serious accidents. The defect reconstruction is important for nondestructive evaluation. Eddy current pulsed thermography (ECPT) is a well-known nondestructive testing and evaluation method, but hardly reconstruct fully defect profile. Electrical impedance tomography (EIT) shows promising potential in defect profile reconstruction, but suffers from electrode number limitation. In this article, EIT is introduced to ECPT image sequences processing, and a new method, induced current thermo-electrical impedance tomography, is developed. The proposed method takes each infrared camera pixel as a virtual electrode, captures the electric current distribution with spatial resolution as high as camera, and reconstructs conductivity distribution at pixel level from which the defect profile can be identified. Experiments with different defects are carried out to verify the performance of the proposed method.

A new distributed filtering problem is fully studied in this article for time-varying systems over sensor networks under measurement errors and measurement censoring, where the measurement error is modeled as stochastic sensor bias driven by a dynamical equation and the measurement censoring is described by the Tobit measurement model. To reduce data congestion and transmission burden, a weighted try-once-discard protocol (WTODP) is applied to transmission channels to efficiently orchestrate data communication. The transmission priority is determined in a dynamical way depending on the importance of missions. The aim of this article is to construct an optimal distributed Tobit Kalman filter (TKF) such that filter parameters are rigorously determined in the minimum mean squared error sense under the consideration of the bias, censoring and WTODP effects. Specifically, sparsity of the network topology is comprehensively considered by using the novel matrix simplification technique. Furthermore, the resultant filtering error is ensured to be exponentially bounded in the mean squared sense. Finally, an illustrative example is used to show the applicability of the proposed filter.

This article proposes a novel dynamic event-triggered scheme for nonlinear multiagent systems under denial-of-service (DoS) attacks via an adaptive fuzzy resilient control method. At the beginning, fuzzy logic systems are utilized to identify the unknown system dynamics. Then, a reliable attack detection mechanism forms the basis for establishing a dynamic event-triggered protocol, where dynamic parameters are introduced to adjust the threshold of event-triggered conditions. Compared with common attack detection methods relying on residuals between system and observer values, a novel and reliable mechanism for detecting DoS attacks is proposed, grounded in the logical relationship of voltage level signals derived from the outputs of detection components. Finally, a backstepping recursive design framework is utilized for constructing an event-triggered adaptive fuzzy controller. Through the Lyapunov analysis, it is strictly demonstrated that, even under DoS attacks, the followers remain inside the leaders' defined convex hull. The effectiveness of the presented control scheme is illustrated through the simulation results.