As a power source for autonomous underwater vehicles (AUVs), lithium-ion batteries play an important role in ensuring AUVs’ electric power propulsion performance. An accurate state of charge (SOC) estimation method is the key to achieving energy optimization for lithium-ion batteries. Due to the complicated ocean environments, traditional filtering methods cannot effectively estimate the SOC of lithium-ion batteries in an AUV. Based on the standard extended Kalman filter (EKF), an adaptive iterative extended Kalman filter (AIEKF) method for the SOC in an AUV is proposed to address the traditional filter’s problems, such as low accuracy and large errors. In this method, the adaptive update is introduced to deal with the uncertain noise from the lithium-ion battery. The iteration is used to improve the convergence speed and to reduce the computational burden. Compared with the EKF, iterative extended Kalman filter (IEKF) and adaptive extended Kalman filter (AEKF), the proposed AIEKF has a higher estimation accuracy and anti-interference capability, which is suitable for the AUV’s SOC estimation. In addition, based on the second-order equivalent circuit model of the lithium-ion battery, a forgetting factor recursive least squares (FFRLS) method is proposed to deal with the multi-variability problem. In the end, four different methods, including EKF, IEKF, AEKF, and the proposed AIEKF, are compared in computational time. The experiment results show that the proposed method has high accuracy and fast estimation speed, meaning that it has good application potential in AUVs.

The deployment of external wireless charging infrastructures for unmanned aerial vehicles (UAVs) has faced several challenges, including as the requirement for accurate location, the expensive nature of charging multiple loads, and the absence of system robustness. This article suggests a new spatial magnetic field configuration for transmitting coils in wireless power transfer systems to tackle these problems. The construction features a square base with a rhombus embedded inside it, along with four rectangular sides that are coiled in a noncrossing manner. This configuration ensures a consistent distribution of magnetic field in three dimensions. In order to guarantee that many UAVs are charged simultaneously without interfering with one another, the LCC -S topology is used to accomplish the characteristic of constant current at the main side and constant voltage at the output side. During UAV hovering, output dc–dc is combined with charge management to achieve hovering power supply and constant current charging with minimum size. The experimental results show that when the UAV hovers in the three-dimensional conical space volume above the WPT platform, it maintains a stable output power with an approximately constant 84.5% transmission efficiency. A video file demonstrating wireless charging testing for drones is attached to this article.

To tackle the complex wireless power supply requirements in the Automated Material Handling System (AMHS) of semiconductor wafer factories, this paper presents a design method for a magnetic coupling mechanism based on a Multi-Segment Wireless Power Transfer (MSWPT) system for dynamic wireless power supply in segmented track configurations. Firstly, the track is approached using Inductive Power Transfer (IPT) technology combined with an LCC-S resonant structure transmitter (Tx). Following this, the feasibility of the H-type pickup is assessed through magnetic and electrical circuit analyses, which leads to the preliminary determination of the pickup dimensions by means of finite element magnetic and thermal simulations. Furthermore, an analysis of the mutual inductance drop is conducted under various track structure parameters during track crossing and curve negotiation operation conditions. Secondly, a dual-coil winding method is proposed to reduce the insulation stress on the PCB board. Additionally, a method for calculating the wire length and a design process for the overall parameters of the pickup are derived. Finally, two Txs and a 1.5 kW power receiver (Rx) were designed to verify the mutual inductance fall under the aforementioned conditions. During low-speed full-load operations, a constant-voltage output was achieved through the proposed dual-loop PI control strategy, thereby meeting the requirements for a constant-voltage output in industrial applications.

In the electric vehicle wireless power transmission system, the high-frequency alternating magnetic field between the transmitter and receiver can have a certain impact on the health of living organisms and may even lead to lesions. In addition, metal foreign objects in an alternating magnetic field can cause their own heating or even cause fires due to the eddy current effect, so foreign object detection is an essential function in the wireless power transmission system of electric vehicles. In order to prevent metals and living organisms from entering the charging area and causing harm to the charging system and living organisms, this paper proposes a method for detecting living organisms and metal foreign objects. Firstly, the equivalent circuits for the detection systems of the living organism foreign objects and metal foreign objects are established, respectively, and the working theory of the detection system is analyzed by deriving equations. Secondly, the comb capacitor simulation model was constructed, and the comb capacitor electrode spacing, wire thickness, and capacitor spacing were designed based on the scale factor γ to explore the effects of the height and bottom area of the living organism’s foreign object on the comb capacitor. We constructed a simulation model of the detection coil and designed the inner diameter D, the number of turns N, and the wire spacing S of the detection coil according to the scale factor β. An arrayed detection coil and comb capacitor combination mode is proposed to realize the function of the simultaneous detection of metal and living organism foreign objects, and a compensation capacitor is introduced to keep the detection system in a resonant state. Lastly, a platform for foreign object detection experiments was set up to detect metal screws and beef chunks compared to the detection area without foreign objects. Metal screws entering the detection area cause a 20% voltage drop in the detection circuit resistor, and beef chunks entering the detection area cause a 30% voltage drop in the detection circuit resistor, so the detection method is effective in detecting both metals and living organisms. The feasibility of the combined mode of arrayed detection coils and comb capacitors was verified.

Dynamic wireless power transfer (DWPT) is gaining traction in logistics for its continuous and flexible power delivery. However, multireceiver DWPT systems face significant challenges in ensuring current sharing and maintaining output voltage stability. This article proposes a solution for multireceiver DWPT systems using a virtual dc motor (VDCM)-based coordinated control strategy, effectively addressing these two critical issues. The proposed strategy integrates a droop control mechanism to achieve efficient current sharing among multiple receivers, while a VDCM control loop enhances output voltage stability. In addition, this article theoretically analyzes the system’s stability and dynamic performance and establishes a simulation model. Experimental results from a 1.2 kW prototype system show that the proposed strategy significantly reduces voltage fluctuation and current deviation, achieving an efficiency of 89.76%, with output current deviation under 5% and bus voltage fluctuation below 1%. This article provides an effective approach to improving the performance and stability of multireceiver DWPT systems in complex operating environments.

Autonomous underwater vehicles (AUVs) are widely used for ocean exploration; however, the way they are replenished becomes the biggest issue limiting their range and efficiency. A dual transmission coil wireless power transfer (DTCWPT) system based on parity–time (PT) symmetry is proposed in this paper to realize an autoadaptive constant power transmission. A shielded housing structure for coils is equipped to realize WPT in the ocean. In the offset experiments, the proposed dual transmitting coil structure was able to achieve a stable power transmission of 39 W within an offset range of 8.1 cm. It is obvious that the DTCWPT system based on PT symmetry could charge an AUV in the ocean with high robustness. This paper provides a novel solution based on DTCWPT for AUV energy supply. The proposed DTCWPT system could offer remarkable improvements in the navigation performance of AUVs.