bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Control Strategy of Manipulator Based on Simulation
Authors: Su JiaLei 
Published: November 2021

Abstract
The force supple control method of robotic arm has been widely researched internationally for many years, and its specific use varies according to the structure of the robotic arm, the location of the sensor, the working space environment, and other factors. Based on the force control principle and control method of the space robot arm, this paper adopts the position-based Cartesian spatial impedance control and proposes an effective forcesmoothing control method after pre-processing the feedback signal of the six-dimensional force sensor installed at the end of the space robot arm with the coordinate system conversion. In addition, the proposed position-based Cartesian spatial impedance control method is modeled and simulated to analyze the effect of each control element on the force-following control effect, to find out the control conditions that can optimize the force-position control effect, and finally to optimize the impedance parameters. This study aims to promote the rapid development of the field of robotic arm control.
Study on the Influence of Inserting Clearance on the Voltage Standing Wave Ratio in RF Connector
Authors: Li Xiang , Tong Lijun , Cai Libing , Xie Qian , Xu Jinling , Zhao Min , Shi Guangqin 
Published: November 2021

Abstract
RF (Radio Frequency) connector has been extensively applied in the field of communication for it is a key device of transmitting microwave signals. If he RF connector end is designed improperly in dimension, a clearance will be observed after inserting, resulting in an abnormal phenomenon in the voltage standing wave ratio (VSWR) of the RF connector. This paper studied the influence of the inserting clearance of RF connector on the voltage standing wave ratio through theoretical analysis and performance simulation. Moreover, the solution to the abnormal voltage standing wave ratio was also proposed. At last, the abnormal phenomenon of voltage standing wave ratio of the connector in the inserting process was handled by means of carrying out optimization design and test validation on the RF connector.
UAV detection algorithm based on the difference of power dispersion
Authors: Yuan Cheng , Jia Long-fei , Cheng Hong-li 
Published: November 2021

Abstract
With the development and popularization of UAVs, illegal UAV accidents occur frequently. The complex signal environment in the city brings difficulties to detect UAV signal. In order to detect the UAV signal in the complex environment, this paper proposes a UAV detection algorithm based on the difference of power dispersion in time. Firstly, the algorithm performs short-time Fourier transform on the signal to obtain the time-frequency matrix. Secondly, The fixed frequency interference in the matrix is filtered by the local adaptive threshold. Finally, the UAV image transmission signal is detected by the discrete difference in time between image transmission signal and WiFi. Simulation results show that the algorithm can detect UAV signal under constant frequency interference and WiFi interference.
Stiffness Evaluation and fast matching method of mechanical composite structure
Authors: Lv Jishuang 
Published: November 2021

Abstract
Stiffness evaluation can improve the reliability and safety of combined machinery, which is often used to evaluate the performance of combined machinery. In order to study the stiffness evaluation method and rapid matching of mechanical composite structure, the composite machinery composed of high-power diesel is taken as the research object. The results show that the error between test mode and calculation mode is no more than 10%, indicating the reliability of finite element simulation model; two characterization methods of static stiffness and dynamic stiffness are determined, and the analysis methods of two characterization methods of combined machinery are discussed one by one. Taking the combined machinery of body, main bearing cap and oil pan as the research object, the overall stiffness characterization data of three parts are obtained one by one; finally, the principles of mechanical combination Stiffness Evaluation and rapid matching are summarized. This study provides a reference for Stiffness Evaluation and rapid matching of combined mechanical structures.
Research on Nano Refrigerant and Nano Lubricant to Improve Energy Saving of Refrigeration System
Authors: Kong Dexia , Wei Na , Dong Min 
Published: November 2021

Abstract
In order to improve the performance of the refrigeration system, researchers have introduced nano-refrigerant and nano-lubricating oil into the latest development of airconditioning system. However, explaining the role of nano-particles based on the physical phenomena affecting the vapor compression refrigeration system (VCRS) has been limited in experiments. Therefore, this paper reviews the mechanism of using nano-refrigerant and nano-lubricating oil to improve the performance of VCRS, discusses the compression work of the refrigeration system using nano-refrigerant and nano-lubricating oil and VCRS performance parameters such as COP and COF, and relates them to the overall performance of the system. The results show that the main factors affecting the performance of VCRS are heat transfer enhancement, refinement of the characteristics of cold oil mixture and improvement of tribological properties. The influence of nano-refrigerant and nano-lubricating oil on heat transfer, cold oil mixture and tribological properties of VCRS improves the overall performance of VCRS. Therefore, nano-refrigerant and nano-lubricant are expected to be the best choice to improve the efficiency of VCRS.
An improved simulated load test system
Authors: Hua Liang , Qi Jiaen , Huang Wei , Zhang Sijiang , Gao Feng , Peng Shengjiang 
Published: November 2021

Abstract
A miniaturized analog load-checking relay protection test device is developed in this paper, in which a high-precision wireless phase volt-ampere test device is configured. This device, characterized by intelligence and ease of operation, realizes the detection of the transformation ratio, polarity, phase, etc. of the secondary wiring of the transformer in the smart substation merging unit and the conventional substation. It meets the testing requirements of smart substations, and can test bus differential protection, line protection, and various protections such as main transformer differential.
Research on CNN-based intelligent recognition method for negative images of weld defects
Authors: HUANG Jiawei , BI Caixia , LIU Jiayue , DONG Shaohua 
Published: November 2021

Abstract
The existing technology of automatic classification and recognition of welding negative images by computer is difficult to achieve a multiple classification defect recognition while maintaining a high recognition accuracy, and the developed automatic recognition model of negative image defect cannot meet the actual needs of the field. Therefore, the convolutional neural network (CNN)-based intelligent recognition algorithm for negative image of weld defects is proposed, and a B/S (Browser/Server) architecture of weld defect feature image database combined with CNN is established subsequently, which converted from the existing CNN by the migration learning method. It makes full use of the negative big data and simplifies the algorithm development process, so that the recognition algorithm has a better generalization ability and the training algorithm accuracy of 97.18% achieved after training. The results of the comparison experiments with traditional recognition algorithms show that the CNN-based intelligent recognition algorithm for defective weld negatives has an accuracy of 92.31% for dichotomous defects, which is significantly better than the traditional recognition algorithm, the established recognition algorithm effectively improving the recognition accuracy and achieving multi-category defect recognition. At the same time, the CNN-based defect recognition method was established by combining the image segmentation algorithm and the defect intelligent recognition algorithm, which was applied to the actual negative images in the field with good results, further verifying the feasibility of CNN-based intelligent recognition algorithm in the field of defect recognition of welding negative images.
A packet replication algorithm for delay tolerant networks based on multi-metric
Authors: Liu Yongguang 
Published: November 2021

Abstract
Utility function of packet is often used to decide how to replicate packet in DTN networks. But this method has more uncertainty and relies on a single performance metric. For this problem, in order to reduce the impact of a single metric uncertainty, multiple utility metrics are introduced in the new algorithm. A packet replication probability calculation method based on entropy weight is designed. By calculating the entropy weight of each metric, the algorithm obtains the replication probability of each packet and takes the probability as the priority of packet replication. Because of considering the two metrics of packet expected transmission delay and node encounter possibility, the algorithm effectively reduces the influence of encounter time distribution problem and direction prediction problem in the original algorithm, and reduces the uncertainty of utility function. Simulation results show that the algorithm reduces the packet replication number and the average delay, improves the successful packet delivery rate. The overall performance of the network is further improved.
Spectral Analysis of (Multi-) Pulse-Position Modulation
Authors: Gu Silyu , Liang Chunliang , Zhang Jiaxu 
Published: November 2021

Abstract
Nowadays, laser communication has received great achievements owing to its advantages, e.g., large channel capacity, easy miniaturization of communication system and strong anti-interference ability in different conditions. Pulse position modulation (PPM), as an important modulation technology in laser communication system that transmit signal with lower power, is attracting much attention. However, the performance of the modulation scheme highly depends on the bandwidth of transmission. To remedy this defect of PPM, the multipulse position modulation (MPPM) scheme is proposed to increase the accuracy and bandwidth limit. This modulation scheme has stronger anti-interference ability than PPM. Therefore, there has been rising interest in studying the characteristics of the multi-PPM. In this article, we developed an appropriate mathematical model to represent a PPM transmission, analyzed the spectrum of the transmission and characterized the bandwidth of this transmission. Compared with benchmarks of MPPM scheme, its performance has been discussed. According to the analysis, MPPM strongly increases band-utilization efficiency, however PPM has a better bit error rate (BER) performance than MPPM.
Research on temperature acquisition system of printing machine oven based on wireless Sensor network
Authors: WU Rui , WANG Yi-ming , WANG Yu-hu 
Published: November 2021

Abstract
Aiming at the problems such as limited transmission distance of traditional temperature data, complex wiring and aging line, ZigBee wireless network is introduced into the temperature acquisition system of the intaglio printing machine oven, which makes the whole system easy to operate and simple, and greatly improves the transmission distance of temperature signal. The composition of the temperature monitoring system and the hardware circuit of the ZigBee master node are described, including DC 5 V power supply circuit and USB interface power supply circuit, the connection circuit between the RADIO frequency board and the backboard, to realize the construction of the network and the wireless reception of temperature data. To realize the construction of the network and wireless reception of temperature data. It combines ZigBee wireless communication technology to complete real-time transmission of multi-point temperature data, realize real-time LCD display of multi-point temperature data collected by DS18B20, and realize ZigBee networking function based on ZigBee protocol stack.
Design of Digital Pulse-Position Modulation System
Authors: Yu Nanjun , Wang Pengzhao , Zhuang Zhiyi 
Published: November 2021

Abstract
Pulse-Position Modulation (PPM) is a modulation method that only makes every pulse in the carrier pulse sequence change with time but without changing the shape and amplitude of the pulse signal. In this paper, a PPM system is designed. Firstly, an appropriate mathematical model is established to represent PPM transmission, and the shape of the pulse signal is designed. After that, we write the code and add a white Gaussian noise channel. Then the transmission process is simulated and visualized. At last, the error rate of the scheme is analyzed and discussed through MATLAB simulation then compared with other modulation methods. The goal of this paper is to study PPM by designing a PPM system fully. Besides, our method is compared with other modulation methods to understand the advantages and disadvantages of PPM. This may help other scholars to design and research the PPM system.
Testability Analysis Method of Radar Equipment Based on Dependency Model
Authors: Du Xiaoshuai , Hu Bing , Qin Jian 
Published: November 2021

Abstract
In order to improve the testability design level of radar equipment, achieve rapid detection and isolation of faults, and reduce the life cycle cost of the system, a testability analysis method of radar equipment based on correlation model is proposed. The basic process of correlation model modeling is introduced. On this basis, the optimization method of test points for fault detection and isolation and the generation method of fault diagnosis strategy are analyzed. The effectiveness of the proposed method is verified by applying it to radar transmitting subsystem.
Research on Comparison of LiDAR and Camera in Autonomous Driving
Authors: Wang Peide 
Published: November 2021

Abstract
With the improvement of vehicles automation, autonomous vehicles become one of the research hotspots. Key technologies of autonomous vehicles mainly include perception, decision-making, and control. Among them, the environmental perception system, which can convert the physical world’s information collection into digital signals, is the basis of the hardware architecture of autonomous vehicles. At present, there are two major schools in the field of environmental perception: camera which is dominated by computer vision and LiDAR. This paper analyzes and compares the two majors schools in the field of environmental perception and concludes that multi-sensor fusion is the solution for future autonomous driving.
Study on Influencing Factors and Laws of Fuel Injection Consistency of Common Rail Injector
Authors: Zhang Ziwei , Xu Chunlong 
Published: November 2021

Abstract
In order to study the influence of parameters of common rail injector internal components on cycle injection consistency, its simulation model is established by AMESim, and the model is validated by the experimental injection rate data. The effects of solenoid valve spring preload, gag bit lift, fuel discharge hole diameter, fuel inlet hole diameter, needle valve lift, needle valve preload and nozzle diameter on the change of injection quantity under different operating conditions are studied by simulation method, and the impact weight of each parameter on fuel injection consistency is analyzed. The results show that the preload of solenoid valve, fuel discharge hole diameter, oil inlet hole diameter, needle valve lift and nozzle diameter are the main parameters affecting the consistency of cycle injection. The percentages of five parameters influencing on the consistency of cyclic injection are 8.68-16.84%, 11.41-23.68%, 17.2086-37.74%, 12.772-18.34% and 9.69-37.27% respectively.
Numerical Simulation on Gas-Solid Two-Phase Flow in Horizontal Pneumatic Conveying Pipe Based on DPM Model
Authors: Guo Zihan , Zhang Jun , Huang Jinman 
Published: November 2021

Abstract
The determination of pipe deposition and optimum conveying velocity in pneumatic conveying has an important impact on conveying efficiency. The Euler-Lagrange method DPM model is used to analyse five different particle sizes and densities of small particles, and the flow pattern in the horizontal pipeline at different particle sizes and densities is derived from the graphs of the maximum discrete phase concentration, particle trajectory and discrete phase concentration distribution for each working condition. The simulation results show that the deposition increases with particle size and density, the optimum conveying speed increases with particle size and density, the larger the deposition, the larger the required conveying velocity. The velocity of 2 m/s can make the particles below 20μm suspended transport, the velocity of 4 m/s allows particles with a particle size of 30μm and a density of 1000 kg/m3 or less to be transported in suspension and 6 m/s allows particles with a density of 2000 kg/m3 or less to be transported in suspension. The aim is to provide a reference for the design of pneumatic conveying systems and the selection of the optimum conveying velocity.
Experimental Study on the Effect of Locally Convergent Configurations on the Flow Pattern in PMMA Microchips
Authors: Zhang Jinsong , Liu Zhongxin , Wang Chao , Wang Zhiliang 
Published: November 2021

Abstract
The geometries of micro-channel play a key role in forming of digital droplets, and can be real-time or effective controlling methodologies. Local convergence regions are designed in the rectangular cross-section channels on PMMA microchips, in which two-phase coaxial jets are introduced by inserting a syringe needle. The two-phase flow (lubricating oil (continuous phase, flow rate Q
c)/deionized water (dispersed phase, flow rate Q
d)) is considered. Two geometric control variables, the relative position (needle displacement x) and tapering characteristics (convergence angle α), are naturally adopted to discribe such geometry configurations. The micro-flow under the change of these two parameters is mainly studied in this paper. Four kinds of characteristic flow patterns, namely, sausages, slug, dripping and jetting, are found in the experiment, and their occurring parameters and developing dynamic characteristics are discussed. The experiment shows that the increase of inner needle displacement x can produce higher frequency and finer droplets, which is in consistent with our previous results obtained in round tube experiments and simulations. While increasing the convergence angle α, contrarily, takes opposite effects.
Study on the Expansion of Primary Flow for the Mixing Uniformity in the Two-Phase Ejector
Authors: Zheng Lixing , Hu Hongwei , Mi Changning 
Published: November 2021

Abstract
The expansion of primary flow in the suction chamber of the CO2 two-phase ejector is investigated and its influences on the mixing characteristics are analyzed. An ejector model is developed, by constructing differential equations for mass, momentum and energy then get the governing equation. In the suction chamber, the expansion of primary flow and the compression of secondary flow are modeled along the flow path. Based on the constant-pressure mixing theory, the pressure equilibrium positions of two stream (namely at the inlet and inside of mixing chamber, respectively) are considered. The mass and energy transfer in the mixing chamber were analyzed by using the double-flow model formulation. The ejector performance parameters are obtained for the different operation conditions, and the distributions of temperature and velocity of two streams in the mixing chamber are presented. The simulation results showed the influence of primary flow expansion on the pressure lift ratio was relatively obvious, and the larger expansion distance was helpful to improve the mixing efficiency and decrease the thermodynamic entropy change during the mixing. Moreover, the temperature of secondary flow for lower primary flow pressure presented larger descent rates at the initial of mixing. This work is helpful for the improvement of ejector theoretical model and the optimization design.
Analysis of Characteristics of Damping Valve Based on High-Order Discrete Scheme
Authors: Pan Shichao , Li Weimin 
Published: November 2021

Abstract
In this paper, based on the high-order discrete scheme, a two-way fluid-solid coupling numerical simulation is for the damping valve plate. According to the discrete method, the governing equations of fluid structure coupling of damping valve plate are studied, including the basic conservation laws; Meanwhile, it analyzes the discretization of the control equation, including the discretization method and the high-order discretization format when the finite volume method is adopted. And based on this discrete format, a numerical simulation was performed on the damping valve, the oil flow condition is analyzed, and the velocity of the throttling hole at different time points and the throttling pressure are analyzed.
Feasibility of Boosting Low-Energy-Quality Steam by Using Wave Rotor
Authors: Dai Yuqiang , Tang Zhipeng , Li Mohan , Hao Gang , Zhang Luwei , Wu Jintao 
Published: November 2021

Abstract
Owing to the difficult utilization of the low-pressure level in the process industry, the low-energy-quality steam is often condensed to recover the demineralized water or just discharged directly, causing a huge waste of thermal energy. A novel technology of enhancing the steam’s energy quality by using the wave rotor based on the principle of moving shockwave compression is proposed. The supercharging ability of 3-port wave rotor is studied by meaning of 1-dimension unsteady theory and computational fluid dynamic. A practical thermodynamic flowsheet of boosting the low-pressure steam driven by high-pressure steam is also proposed and analysed in detail. As an example, to boost the saturated steam of pressure 1.0 MPa to 1.953 MPa, a three-stage wave rotor solution is proposed and is verified its feasibility. The high supercharging ratio and entrainment ratio of the wave rotor are much higher than the traditional steam ejector shows the feasibility of enhancing energy-quality of low-pressure steam.
A Quantitative Study of Carmine Aqueous Solution Based on Drop-Coating Deposition Micro-Raman Spectroscopy (DCDR)
Authors: Huang Wei 
Published: November 2021

Abstract
Carmine is a kind of colorant which is widely used in food, beverage, medicine, cosmetics and tobacco industry. However, excessive use of carmine may lead to the risks of carcinogenic, teratogenic and mutagenic, which seriously threaten the health and safety of consumers. In this paper, DCDR technology is utilized to develop a quantitative method for the detection of carmine, which requires only a small volume deposition of analyte solution (several μL) on a suitable hydrophobic substrate. The conventional Raman spectrum of carmine aqueous solution and corresponding Raman spectrum using DCDR method were compared, illustrating a much higher sensitivity for DCDR method. The Raman spectra of carmine aqueous solution with different concentrations of 100, 50, 10, 8, 4 and 2μg/mL are acquired from the spots on the “coffee-ring” with DCDR method. Using DCDR method, a good linear relationship has been observed between the intensities of the two characteristic peaks, 1364cm−1 as well as 1572cm−1, and the concentrations of the solution, with the linear correlation coefficient of R2>0.99. The results illustrate that DCDR method has a good potential in the quantitative analysis of colorant like carmine, providing a promising technique for a rapid detection for food additives.