In Situ Observation of Liquid Solder Alloys and Solid Substrate Reactions Using High-Voltage Transmission Electron Microscopy

The complex reaction between liquid solder alloys and solid substrates has been studied ex-situ in a few studies, utilizing creative setups to “freeze” the reactions at different stages during the reflow soldering process. However, full understanding of the dynamics of the process is difficult due to the lack of direct observation at micro- and nano-meter resolutions. In this study, high voltage transmission electron microscopy (HV-TEM) is employed to observe the morphological changes that occur in Cu6Sn5 between a Sn-3.0 wt%Ag-0.5 wt%Cu (SAC305) solder alloy and a Cu substrate in situ at temperatures above the solidus of the alloy. This enables the continuous surveillance of rapid grain boundary movements of Cu6Sn5 during soldering and increases the fundamental understanding of reaction mechanisms in solder solid/liquid interfaces.

Edge detection of foreign matter suspension image of high voltage transmission line based on improved Canny operator

In the edge detection of foreign object hanging image of high voltage transmission line, it is easy to appear that multiple responses will appear at one image edge point, which affects the detection effect. Based on the improved Canny operator, an edge detection method for foreign matter suspension image of high voltage transmission line is designed. The collected image is preprocessed in three steps: gray processing, optical correction and noise reduction, so as to better reflect the characteristics of the original image and improve the image quality. The non-uniform distribution of potential energy of foreign body hanging image data field is used to locate the image area of foreign body hanging. The morphological filter can extract the local noise and make the image clearer. The Canny operator is improved to obtain the partial derivative of the distance measurement function and automatically update the threshold to eliminate the multi-level response. The test results show that the method in this paper is better than the image edge detection method based on Canny operator and Sobel operator in three indexes: positive detection rate, false detection rate and missed detection rate.

Design of vision system for high voltage transmission line obstacle Removal Robot

Aiming at the problem of low visual co direction rate of high-voltage transmission line obstacle Removal Robot in traditional system, a new vision system of high-voltage transmission line obstacle removal robot is designed. In the hardware part of the system, the storage structure of DSP, TMS32DC541Q and image sensor are designed; at the same time, through the visual foreign object recognition of high-voltage transmission line obstacle removal robot, the visual image threshold of high-voltage transmission line obstacle removal robot is calculated, the visual judgment of high-voltage transmission line obstacle removal robot is realized, and the system design is completed. The experimental results show that compared with the traditional vision system, the designed vision system of high-voltage transmission line obstacle Removal Robot effectively improves the degree of the same direction with the original image and meets the practical application requirements.

Outage Performance of Full-Duplex Relay Networks Powered by RF Power Station in Ubiquitous Electric Internet of Things

This paper investigates a full-duplex relay network assisted by radio frequency (RF) power station in ubiquitous electric Internet of Things (UEIoT), where a wireless sensor on high voltage transmission line collects electric data and then transmits data to a destination via a full-duplex decode-and-forward relay. The destination receives and processes the data to inspect the state of high voltage transmission line. Both the sensor and relay do not have fixed energy source; so, they first have to harvest energy from a RF power station and then complete information transmission by using the harvested energy. As the line-of-sight (LOS) propagations often exist in outdoor application scenarios of UEIoT, the Rician fading channel is adopted in the network. To explore the system outage performance, the explicit expressions of the outage probability and throughput of the system are derived by using mathematical analysis. Simulation results validate the correctness of our theoretical analysis and also evaluate the effects of system parameters and deployment position of power station on the outage performance.