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The paper first summarizes the path planning, then divides the path planning algorithm suitable for UAV into global path planning and local path planning in continuous domain. According to the related algorithms, the background, design ideas, advantages and disadvantages are summarized. Finally, the prospect of the development direction of future research.

This paper presents discussions on the design of Semiconductor-based galvanic isolation (SGI)-based vehicle on-board battery chargers. SGI is a paradigm shift compared to traditional transformer-based solutions by using switched capacitor circuits to realize galvanic isolation. Two major SGI-based battery charger topologies are compared, and a two-stage Totem-pole + SGI dc/dc solution is selected due to higher efficiency. Based on the topology, the touch current (TC) issue is modelled and analyzed, and a buck-boost-based active compensation circuit is proposed with local sensing and control. At last, a 2-kW SGI charger is prototyped and tested, and the efficiency of the dc/dc stage maintains above 98%. With the proposed touch current compensation circuit, the charger meets the safety standards by passing the TC test.

In spectral quantitative analysis, the accuracy and complexity of the designed prediction model will be negatively affected by enormous data volume and noise of the original spectrum. This paper presents a dimensionality reduction and noise decreasing method for original spectrum analysis based on Fourier series fitting (FSF). By extracting features using FSF, the original spectrum data will be mapped into Fourier series, and a regression prediction model using partial least squares (PLS) is established. The experimental analysis suggests that FSF method, compared with PLS, discrete fourier transform (DFT), artificial neural networks (ANNs) and genetic algorithm with PLS (GA-PLS), can produce better results considering the running time, the number of input variables and prediction accuracy.

With off-line power supplies moving towards MHz switching frequency range, the converter's bus capacitor becomes the bottleneck of further improvement of power density. Partial constant power operation is effective in reducing the bus capacitance and capacitor current stress for low power applications. However, its impact on circuit operation and circuit design have not been studied thoroughly. With the developed circuit operation and loss model, this paper presents design considerations and power loss analysis of MHz AC/DC converters in partial constant power operation. Based on the models, an adaptive constant power control is also proposed to improve the light load efliciency. A 70 W, MHz CrM GaN-based AC/DC converter prototype has been prototyped to validate the analysis and circuit operation method. Compared with PFC operation, partial constant power control exhibits an efficiency drop of less than 0.5 %, but a 50 % reduction of bus capacitance is realized. With the proposed adaptive constant power control, the light load efficiency can be improved by roughly 0.5 %, which is similar as PFC operation. At the end, the possibility of extending the proposed operation method to higher power applications is also discussed.

This paper presents the touch current (TC) suppression for the semiconductor-based galvanic isolation (SGI) solution. The solution achieves galvanic isolation by utilizing semiconductor switches to deliver differential-mode (DM) power during their ON states, while sustaining common-mode (CM) isolation voltage and blocking CM leakage current during their OFF states. In this solution, TC is resulted as the switch output capacitance is charged by the CM voltage at every switching event, and the TC rises as the switching frequency increases, which limits the system power density. This paper reviews multiple TC-suppression approaches for the SGI to meet the safety standard IEC60950. These approaches include preventing the TC generation, increasing CM impedance, bypassing the TC, and partially reduce the TC. Among them all, it is practical to reduce the TC via partial compensation for the switch output charge, using distributed auxiliary current-source circuits. To verify this approach, a simplified off-line power supply with a SGI-based dc/dc stage is built and tested. The results show the TC can be reduced effectively. It also allows the converter to operate at higher switching frequency to achieve higher power density, while meeting the IEC60950 TC requirement.

In this paper, a low-cost planar antenna array structure made of tapered dielectric image-line (DIL) radiators with a T-junction type feeding configuration is presented for Ka band frequency range. The radiation beam can be steered by changing the operation frequency. A beam deflection of 12° in horizontal plane is achieved by 2 GHz change in the operation frequency. A 22 dB directivity is estimated for a 3-element array structure. The measurement results are presented and are compared with the simulation results.

A dielectric measurement method based on using dielectric image guide (DIG) is presented. This method is ideal for characterization of very small liquid samples, e.g. in the range of mul or less, and has the advantage of broadband frequency measurement. The open structure of DIG makes it very convenient to place the liquid droplet at a predetermined location.

In this paper, a high-gain tapered dielectric image-line (DIL) antenna array is presented for 30 GHz frequency range. Each element of the array is designed and optimized for maximum gain and minimum side-lobes. A novel array structure is proposed to increase the gain and suppress the side-lobs. An estimated 21.5 dB gain has been achieved with a 3-element array structure. The measurement results are presented and are compared with the simulation results.