Development and Implementation of High Precision Positioning Technology for Electric Vehicle Wireless Charging Coils

This paper mainly studies the development and implementation of the positioning technology of the electric vehicle wireless charging coil, so as to accurately detect the position deviation of the receiving coil, so that the electric vehicle wireless charging system can provide electric energy for electric vehicles more efficiently. Based on the positioning method of electric vehicle based on three detection coils, this paper proposes a calculation method to describe the offset degree of coil based on fuzzy mathematics theory. The algorithm is verified by simulation and experiment, and the influence factors of the error accuracy and the source of the error are analyzed. The work done in this paper has a strong practical significance for the efficient realization of electric vehicle wireless energy transmission.

Wireless Torque and Power Transfer Using Multiple Coils with LCC-S Topology for Implantable Medical Drug Pump

In this paper, we propose a method of wirelessly torque transfer (WTT) and power (WPT) to a drug pump, one of implantable medical devices. By using the magnetic field generated by the WPT system to transfer torque and power to the receiving coil at the same time, applications that previously used power from the battery can be operated without a battery. The proposed method uses a receiving coil with magnetic material as a motor, and can generate torque in a desired direction using the magnetic field from the transmitting coil. The WPT system was analyzed using a topology that generates a constant current for stable torque generation. In addition, a method for detecting the position of the receiving coil without using additional power was proposed. Through simulations and experiments, it was confirmed that WTT and WPT were possible at the same time, and in particular, it was confirmed that WTT was stably possible.

Efficient Wireless Drone Charging Pad for Any Landing Position and Orientation

A wireless charging pad for drones based on resonant magnetic technology to recharge the internal battery is presented. The goal of the study was to design a robust, reliable and efficient charging station where a drone can land to automatically recharge its battery. The components of the wireless power transfer (WPT) system on board the drone must be compact and light in order not to alter the payload of the drone. In this study, the non-planar receiving coil of the WPT system is integrated into the drone’s landing gear while the transmitting pad is designed to be efficient for any landing point and orientation of the drone in the charging pad area. To meet these requirements, power transmission is accomplished by an array of planar coils integrated into the ground base station. The configuration of the WPT coil system, including a three-dimensional receiving coil and a multicoil transmitter, is deeply analyzed to evaluate the performance of the WPT, considering potential lateral misalignment and rotation of the receiving coil due to imprecise drone landing. According to the proposed configuration, the battery of a light drone (2 kg in weight and 0.5 kg in payload) is recharged in less than an hour, with an efficiency always greater than 75%.

Improved eddy current testing sensitivity using phase information

This paper describes a two-coil eddy current sensor being used in a transmit-receive arrangement at 1 MHz, where the drive and amplification electronics are miniaturised and built directly behind the coil to reduce noise and the effects from cable length. Small, simulated defects are detected, less than 500 microns in length, on titanium and titanium aluminide, which is an increasingly important alloy for aerospace applications. Data is analysed quantitatively in a parametric approach. This experiment uses a transmitting coil driven by a constant current source and a separate receiving coil, where the magnitude and phase of the induced voltage signals on both coils are measured independently. Experimental measurements are validated using finite element modelling and the phase of the signal on the receiving coil in particular is less susceptible to variations caused by changes in lift-off. A combination of experimental and simulation data of 2D surface scans and lift-off measurements show the variation in the magnitude and phase of the eddy current signal with lift-off on Ti, TiAl (Ti-45Al-2Mn-2Nb-1B) and 316L stainless steel. It is also shown that the high-frequency lower noise approach can reliably detect defects of less than 500 microns in length in both Ti and TiAl.

Design of novel coil structure for wireless power transfer system supporting multi-load and 2-D free-positioning

In the classical WPT technology, when the load coil and the receiving coil are not aligned, the receiving power will be significantly reduced. In this paper, a new type of receiving coil named spiral add planar (SAP) coil is proposed, which can make the receiving power of the load coil almost independent of its position. The T-type equivalent circuit analysis method is used to analyze the transmission performance of the WPT system. By calculating the mutual inductance between non-coaxial coils, it can be proved theoretically that when the load coils are located at different positions, the mutual inductance between the SAP coil and the load coil is more stable comparing to the spiral coil or the planar coil. In addition, this SAP coil can support multiple loads and arbitrary movement of the load within the area of the SAP coil. This paper also proposed the concept of radius ratio (that is, the ratio of the radius of the load coil to the radius of the RX coil), and found that when the radius ratio is less than 1/2, the free-positioning characteristic is good. The simulation and experimental results show that when the load coil moves within the range of the SAP coil, the volatility of its S21 value is less than ± 1 dB.

Optimization Design for Receiving Coil with Novel Structure Based on Mutual Coupling Model in Wireless Power Transmission for Capsule Endoscope

Wireless capsule endoscope (WCE) is a promising technology for noninvasive and painless imaging detection on gastrointestinal (GI) diseases. On the other hand, conventional endoscopes with wires could discomfort patients and cause them to vomit and aerosolize coronavirus if the patients are infected with COVID-19. However, there stands a technical bottleneck on power supply for the WCE. With the help of wireless power transmission technology, a hollow receiving coil (RC) is proposed to supply sufficient power and also minimize the size of WCE. A model on mutual inductance between transmitting and receiving coils is proposed to evaluate receiving power when the RC is in a different position and direction of patient’s GI tract. Based on the model, an optimal RC is built to obtain sufficient and stable power. Measurement of mutual inductance with the optimal RC validates high accuracy of the proposed model. The standard deviation of receiving power is very low. WCE with optimum RC gets sufficient power and captures images stably in live pig’s intestine tract. Additionally, the model is little affected by biological tissues. It ensures reliable performance of WCE and makes popular clinical application of WCE possible, which is also a relief to reduce epidemics like COVID-19.

Hollow Receiving Coil and Single Turn Element Analysis on Power for Wireless Capsule Endoscopy

Wireless capsule endoscopy (WCE) is more and more popular in noninvasive detection on gastrointestinal (GI) disease. But the power supply is still a bottleneck. Insufficient power reduces image resolution and frame rate of data transfer, thus, unreliable medical diagnosis. Wireless power transmission (WPT) technology enables power supply for WCE. A hollow receiving coil (RC) with novel structure is proposed to minimize the capsule scale and solve the power issue. Single turn element analysis (STEA) is adopted to directly evaluate receiving power. Receiving power varies greatly when WCE is in different position and orientation of GI tract during the detection process. In some particular misalignment, power drops too low or jumps frequently. Then, optimization design of RC aimed at sufficient and stable power supply is implemented. The STEA is validated on test bench. The error of electromagnetic force is 0.2 V. The least receiving power with the optimal RC is 438.1 mW even in the worst misalignment. In the great majority of position and orientation misalignments, the optimal RC receives power over 650 mW. With the advantage of both computational time and accuracy, STEA is applicable for measurement and analysis on power for biomedical devices utilizing WPT technology, not merely WCE. In vivo experiment in pig's GI is accomplished with the optimal RC. The size of WCE with the novel RC gets smaller. And image stream is clear and fluent, when WCE is in any possible position and orientation of the tract. Four frames are stochastically sampled, in entropy of 7.1148, 7.3070, 7.2041, and 7.2570. Sufficient and stable power supply with the hollow RC enables advanced functions like drug release to come into being in WCE.