bluuebunny/crossref_metadata_2025 huggingface dataset:
A Magnetic Potential-field Downward Continuation Method Based on Accelerated Landweber Iteration
Authors: Wang Ze , Zhang Qi , Pan Mengchun , Chen Dixiang , Liu Zhongyan , Hu Jiafei , Chen Zhuo , Ren Xintian , Zeng Zhe , Wang Zhenxiong
Published: May 2021

A high-precision geomagnetic database is the basis of geomagnetic matching navigation. In the construction of a geomagnetic database, it is necessary to use magnetic field extension technology to construct the vertical height relationship of geomagnetic data, in which downward continuation is mathematically ill-posed, and Landweber iterative method is a common solution. However, the convergence rate of the Landweber iterative method for the “non-smooth“ solution is very slow, resulting in low delay accuracy in dealing with local magnetic anomalies. Therefore, to solve the problem of slow convergence of the Landweber iterative method, a downward continuation method based on accelerated Landweber iteration is proposed in this paper. In the framework of the iterative method, stable upward continuation is used to connect the observation surface with the magnetic field values on the plane with the same height as upward continuation and downward continuation. Then the residual term is constructed by the vertical first-order derivative relation, and then the residual term is modified by using the low-pass filtering characteristic of the upward continuation operator to suppress the high-frequency noise in the residual term and finally update the iterative value. The simulation results of magnetic field models with different field source depths show that the improved method has faster convergence speed and higher extension accuracy when dealing with shallow local anomalies and deep regional anomalies, and under the condition of shallow source model, the continuation error of the improved algorithm is only 60% of that of Landweber iterative method. At the same time, the measured data also verify that the improved method can achieve fast and high-precision downward continuation of a magnetic field.
An Intelligent Geomagnetic Search Navigation Method Based on Evolutionary Gradient Strategy
Authors: Ren Xintian , Zhang Qi , Pan Mengchun , Chen Dixiang , Liu Zhongyan , Hu Jiafei , Chen Zhuo , Wang Zhenxiong , Wang Ze
Published: May 2021

Currently, most of the geomagnetic navigation methods are matching navigation algorithms, which require the geomagnetic maps retrieved in advance, and saved in a database. However, there are a great number of unknown environments exist worldwide that limit the extensive application of the geomagnetic matching method in practice. In this paper, an intelligent geomagnetic search navigation method based on the evolutionary gradient search (EGS) algorithm is proposed. The performance of the search and navigation method is analysed with both simulated and real geomagnetic data. And the conclusion is that compared with other intelligent search strategies, the proposed algorithm has better navigation performance with less average navigation error, 161m, which is equivalent to the most traditional geomagnetic matching algorithms. Thus, the EGS algorithm proposed in this paper can effectively improve the performance of geomagnetic navigation without prior geomagnetic information.
Data-driven multi-objective optimization of laser welding parameters of 6061-T6 aluminum alloy
Authors: Wu Jianzhao , Zhang Shuaikun , Sun Jiahao , Zhang Chaoyong
Published: May 2021

In this paper, a data-driven multi-objective optimization approach using optimal Latin hypercube sampling (OLHS), Kriging (KRG) metamodel and the non-dominated sorting genetic algorithm II (NSGA-II) is presented for the laser welding process parameters on 6061-T6 aluminum alloy. The experiments are designed by OLHS and carried out to obtain the data results. The complex relationship between the process parameters and the bead profile geometry is established by KRG using the data results. The accuracy of the established KRG metamodel is validated using experiments. Then, NSGA-II is used to explore the design space and search the Pareto optimal solutions of process parameters. Besides, the validation experiments were carried out to obtain ideal LW bead profile, which shows that the approach can bring dependable guidance for LW experiments.
Modeling and Motion Simulation of a Stamping Manipulator
Authors: Zhang Weiwei
Published: May 2021

With the development of modern industry, manipulator gradually replaces manual operation. The manipulator needs high accuracy in the process of grasping the workpiece, moving and placing the workpiece. After designing the manipulator according to the working environment and related parameters, it is necessary to model and simulate the manipulator, which has determined whether the motion trajectory is accurate and whether the motion is stable and reliable. As a result, the MATLAB software is used to simulate the motion of the manipulator between two points. It can be seen from the curve of displacement, velocity and acceleration that the manipulator runs smoothly and reliably.
A framework of modelling slip-controlled crack growth in polycrystals using crystal plasticity and XFEM
Authors: Zhang P. , Lu S. , Baxevanakis K.P. , Zhao L.G. , Yu T.Y. , Zhou R.X.
Published: May 2021

Short cracks tend to develop at high and irregular rates compared to macroscopic cracks, making the prediction of fatigue life a challenging task. In this work, a numerical framework combining crystal plasticity model and the Extended Finite Element Method (XFEM) is applied to study the slip-controlled short crack growth in a polycrystal superalloy RR1000. The model is calibrated from experiments and used to evaluate short crack growth paths and rates. Two fracture criteria are used and compared: the onset of fracture is controlled by the total and individual cumulative shear strain respectively, and the crack grows either perpendicular to the direction of maximum principal strain or along crystallographic directions.
Research on the origin of solid super-slip and friction based on Raman spectroscopy
Authors: Zhang Ruijie
Published: May 2021

It is estimated that about 1 / 3 ~ 1 / 2 of the world’s energy consumption is caused by friction and wear. About 80% of the parts of general machinery and equipment are scrapped due to wear. In China, the annual loss caused by friction is more than 4 trillion. Therefore, to explore the origin of friction and realize solid super sliding has become a key point of people’s attention. But the basic scientific principle and mechanism of friction origin are difficult to explore, so how to give a reasonable method to solve this problem is particularly important. This paper focuses on the use of Raman spectroscopy to observe the solid super slip phenomenon and phonon dissipation, through Raman spectroscopy to determine the orientation of molecules on the friction interface, detect the related properties of two-dimensional materials, as well as crystal defects and their apparent morphology to explore the origin of friction, and to reduce the energy loss caused by friction.
Residual Value Evaluation of Operating Pure Electric Vehicles Based on Machine Learning
Authors: Wang Yujiu , Huang Miaohua , Chen Kailun
Published: May 2021

In view of the current imperfect second-hand evaluation system for new energy vehicles, there are limitations such as simple evaluation models, strong subjectivity, and large evaluation differences. This paper establishes the residual value evaluation model for operating pure electric vehicles, combining actual vehicle operation and maintenance data and establishes the residual value rate evaluation model based on the XGBoost algorithm and Boosted Trees enhanced algorithm. The multi-dimensional feature data of vehicle type, service time, mileage and region are extracted by feature engineering, and the evaluation system of residual value rate correction coefficient is established based on AHP. Finally, based on residual value rate evaluation model and the residual value rate correction coefficient system model to optimize the replacement cost method evaluation model, thereby constructing a complete residual value evaluation model. The model is based on actual vehicle operating data and machine learning algorithms, which has strong pertinence and real-time for the residual value evaluation of pure electric vehicles.
Research of uneven arc burning of parallel necks of DC fuse
Authors: Yin Fan , Shen Bing , Wu Zhuang Jin
Published: May 2021

When breaking low current, DC fuse is prone to voltage drop. It is caused by uneven arc burning between parallel necks. The problem of uneven arc burning in parallel slows down the breaking speed of the fuse, and in severe cases causes the fuse to overheat and arc spray. To solve this problem, this paper establishes a mathematical model of fuse arc, a commutation model between parallel necks and a pre-arc time model of necks. Based on Matlab, the current of each branch is calculated as well as temperature of necks. Then this paper explains the cause of uneven parallel arcing and analyzes the influence of the machining error and current on the phenomenon. Finally this paper calculates the minimum current density that fuse can arc evenly in parallel under different machining errors, and the conclusion can be used to guide the design of DC fuse.
Failure analysis of phase B pull rod of HGIS circuit breaker operating mechanism in 220 kV Substation
Authors: Lyu Lei , Chen Hao , Zhang Yanfei , Bai Haolun
Published: May 2021

The B-phase pull rod of HGIS circuit breaker operating mechanism in a 220kV substation was broken at the root. The broken pull rod was analyzed by macro examination, metallographic examination, chemical composition analysis, fracture morphology analysis and impact test to find out the reason for the fracture. The results showed that: 1. Due to the improper heat treatment in the manufacturing process, the metallographic structure of B-phase pull rod appeared network ferrite and widmanstatten structure, which made the material brittle and impact toughness lower than the standard requirements; 2. The content of alloy elements Cr, Ni and Ni were significantly higher than the standard requirements, which reduced the plasticity and toughness of the material; 3. The low temperature of substation environment led to the decrease of material toughness and the viscosity of the lubricant decreased, causing the transmission parts to jam. The joint action of three factors led to cleavage fracture of B-phase pull rod in the stress concentration area.
Fatigue failure and launch safety assessment of gun barrel
Authors: Zheng J , Li H J , Wu B
Published: May 2021

Hundreds or thousands of projectiles have been fired through a gun barrel. Catastrophic fatigue failure of gun barrel due to cyclic loadings by the stresses induced by the combination of high pressure and temperature combustion gas, and projectile with the rotating band interaction with the bore surface, has not yet been understood. In this paper, laboratory hydraulic fatigue tests on simulated gun barrel were performed on MTS Land. The experimental results show that there is an inherent relation between crack propagation in thick-walled tube and the external surface hoop and axial strains. This fact suggests that fatigue failure of gun barrel should be likely prevented by monitoring the external surface strains of the gun barrel and stopping continued firing before a major crack growing up to the critical size.
Beam collimation scheme of laser wireless power supply system for high potential monitoring node of power transmission and transformation
Authors: Feng Huang , Hui Huang , Hui Deng , Yang Tianyi , Zhang Xiangyu
Published: May 2021

Laser wireless power supply technology has the advantages of high energy density, good directionality, small transmitting and receiving aperture, convenient and flexible installation and deployment. It is very suitable for power supply for sensors or mobile electrical equipment in complex high potential environment, such as patrol UAV. Because the beam quality of high-power semiconductor laser is far worse than that of other types of lasers, when it is used as the transmitter of beam shaping system, it must be equipped with corresponding beam shaping system to obtain laser beam with uniform spot, appropriate size and small divergence angle, so as to ensure that the photoelectric cell module has high conversion efficiency and meet the needs of long-distance laser transmission. In this paper, a beam collimation scheme based on aspheric lens group is designed, which integrates optical devices with low cost, reduces the energy loss in the process of laser transmission, and obtains laser beam with certain intensity uniformity. The test shows that the collimator can better meet the parameter requirements of the collimation system.
A nonlinear model between life cycle cost, service time and recycling quality level of waste engine parts under uncertain environment
Authors: Shi Junli , Ma Mingyang , Ma Yundong , Liu Huanyu , Ma Qinyi
Published: May 2021

Engine is the core of auto parts. It has great economic and social benefits for retired engines and their parts by remanufacturing. However, in recycling process, the uncertainty of quality status of retired engines leads to the uncertainty of life cycle cost, which makes it difficult for technicians to evaluate the cost. In order to address the problem mentioned, this study sets up a nonlinear model between the life cycle cost, service time and the quality level of used engine parts by considering damage degree in recycling process of used engine parts as a research index and takes 50 heavy-duty engine connecting rods as an example, which provides a theoretical basis for remanufacturing enterprises to evaluate the cost and determine the remanufacturing process accurately.
Research on an Improved Induction Power-taking Method for Smart Grid Monitoring Equipment
Authors: Yang Mengqin , Yang Jun
Published: May 2021

The development of smart cities is inseparable from the support of smart grids. Transmission lines are the bloodline of the smart grid. Due to the geographical environment and insulation conditions of the transmission lines, the power supply of its monitoring equipment cannot directly transfer electrical energy from the cable. The low-pressure end is transferred to the high-pressure end. In order to ensure the smooth operation of the smart grid, the development of an online monitoring device that can continue to work reliably in different environments is a prerequisite to ensure the effective operation of the transmission line[1]. Aiming at the technical bottleneck of monitoring equipment, this article improves the conventional induction power extraction method, and proposes an induction power extraction method based on parallel resonance, by matching the capacitor in the secondary winding of the magnetic core with the corresponding excitation inductance, parallel resonance occurs, thereby increasing the equivalent impedance of the damping branch where the magnetic core is located, so that the load can obtain more power through another branch. Finally, an electromagnetic core electromagnetic simulation experiment was carried out by using Ansoft Maxwell simulation software to verify the effectiveness of the method.
Effect of two-stage aging on hardness and electrical conductivity of as-extruded 7075 aAluminum Alloy
Authors: Cao Fenghong , Qin Zhaohui
Published: May 2021

The effect of two-stage aging on the microstructure and properties of as-extruded 7075 aluminum alloy was studied by means of hardness, conductivity and microscope. The results show that: in the process of solution and primary aging, with the increase of heat treatment time, the hardness and electrical conductivity of the alloy have little improvement, but there is a strong linear correlation between hardness and electrical conductivity, that is, the change of hardness and electrical conductivity presents the same trend; after two-stage aging treatment, with the extension of aging time, the hardness of the alloy first increases, reaches the peak value, and then decreases gradually, the hardness and conductivity have a strong negative linear correlation; and with the increase of aging temperature and aging time, the hardness of the alloy decreases by 9.6%, while the conductivity increases by 18.6%.
Diaokou River Estuarine Sediment Movement Numerical Simulation Analysis Based on two Dimensional Numerical Model
Authors: Ma Liangchao , Jiang Caodong , Li Dongfeng , Zhang Hongwu , Li Zihao
Published: May 2021

The sediment movement and deposition diffusion regularity of the Diaokou River are related to the safety and stability of the northern coast and coastal ports of the Yellow River Delta, and the deposition of sediment in the estuary will lead to the extension of the river and the increase of river resistance. As a result, the water level of the Yellow River estuary and the lower reaches of the Yellow River rises, which has a negative impact on the flood control safety of the lower reaches of the Yellow River. Therefore, it is of great significance to study the sediment deposition and diffusion law of the Diaokou River into the sea. Using the verified two-dimensional numerical model of marine sediment of estuary rivers, the sediment movement of Diaokou River into the sea is calculated, and the marine dynamic characteristics such as tidal current and tide in the sea area near the Diaokou River into the sea are analyzed. The spatial and temporal distribution of sediment concentration in sediment movement and the increase of sediment deposition thickness in sediment movement are consistent with the analysis results of measured data.
Study on the influence of tunnel construction on existing tunnel below by above-crossing tunnel
Authors: Liu Chun , Zhang Qing , Liu Heng
Published: May 2021

During the construction of the above-crossing tunnel, the surrounding rock of the existing tunnel will be disturbed in different degrees due to the different spacing between the upper tunnel and the existing tunnel. In order to study the regular pattern between the surface deformation of the existing tunnel surrounding rock and the tunnel spacing, the surrounding rock deformation of 10 groups of existing tunnels with different spacing is studied by numerical simulation based on the project of the upper loop section of Chongqing rail transit line 9. The results show that the uplift deformation of the vault of the existing tunnel will be caused by the construction of the upper double-track tunnel, and the final deformation of the existing tunnel is in the shape of “M“. The maximum displacement of the existing tunnel decreases first and then increases with the increase of the transverse distance of the upper crossing tunnel, but the maximum displacement of the existing tunnel does not change much; As the vertical distance between the new tunnel and the existing tunnel increases, the maximum displacement of the existing tunnel decreases linearly within the 3L vertical distance. It gradually stabilized after 3L, indicating that the existing tunnels beyond 3L are almost unaffected by new tunnels.
Online estimation of state of health for lithium-ion batteries in electric vehicles based on voltage integral and temperature
Authors: Chen Kailun , Li Qizhong , Wang Yujiu , Huang Miaohua
Published: May 2021

In order to achieve accurate online State of health estimation of power battery, this paper proposes a method based on voltage integration and temperature. Based on the NASA ternary lithium battery accelerated life test, three groups of battery experimental data are divided according to the difference in temperature and discharge rate. According to the single battery data and battery experimental data required to record in the Chinese national standard documents, the feasibility of voltage integration as a characterization of battery health is verified. Then we discussed the charging and discharging behavior of electric vehicles and combine the Particle Swarm Optimization algorithm to select the voltage integral of the fixed voltage interval in the charging stage as the equivalent health factor of the battery health state, and establish a battery health state estimation model based on the Gaussian process regression with the temperature and voltage integral as input. The proposed method is verified by experimental data. The proposed method is suitable for online estimation of battery health status under different temperatures and different discharge rates. The root mean square error and average absolute error of battery health status estimation are both less than 1.4%.
Exploration of the safety management and maintenance of machinery manufacturing and processing equipment
Authors: Wu Guoming
Published: May 2021

With the rapid development of the economy, various industries are also rapidly growing and progressing, and the machinery manufacturing industry has also made greater breakthroughs. If various industries can achieve the goal of automatic production of machinery, mechanical equipment will be a crucial factor. The machinery manufacturing industry has a lot of room for development, and machinery manufacturing technology has also made tremendous progress. If the machinery and equipment produced by the machinery manufacturing industry become more and more excellent, it needs to try to meet the production needs of all walks of life, and improve the quality of manufacturing equipment. The current problems in the process must be solved, such as equipment failure, safety management.
Instrument Transformers Detection and Calibration with Synchronized Phasor Measurements
Authors: Peng Zhang , Hao Liu
Published: May 2021

Instrument transformers with deviation can lead to biased measurements. It causes problems for various applications that use voltage and current measurements. This paper presents a method for detecting and calibrating instrument transformers using synchronized phasor measurements, while the validity of the proposed method is verified via simulation. It is shown that the proposed method can evaluate the instrument transformers and all the Ratio Correction Factors (RCFs) of instrument transformers can be calculated, which can improve the accuracy of measurements. The proposed approach is robust to system uncertainty and noise.
Motion Simulation Analysis of the Horizontal Sealing Device for the Bulk Material Packaging Machine Based on SOLIDWORKS Motion
Authors: Ning Tingzhou , Zhang Yao , Fu Ling
Published: May 2021

In the past, the horizontal sealing mechanism of the bulk material packaging machine has a cam type and a cylinder type. The cylinder type horizontal sealing mechanism has a great impact when the speed changes, while the cam type horizontal sealing mechanism will cause noise and vibration. In this paper, the three-dimensional model of horizontal sealing device for bulk material packaging machine is carried out by SOLIDWORKS software, and the motion simulation analysis is carried out by using the add-in SOLIDWORKS motion. The results show that the acceleration of the horizontal sealing head for the horizontal sealing device occurs in 1/4 and 3/4 of the entire movement cycle. The horizontal sealing device can adjust the speed to meet the horizontal sealing requirements of different packaging bags. The horizontal sealing device of the bulk material packaging machine designed in this paper provides a reference for improving the packaging efficiency of products.
Cause analysis and preventive measures of 500kV shunt reactor bushing failure
Authors: Yang Xuefei , Yang Youtian , Zhang Gongliao , Yao Ribin , Lv Lifan
Published: May 2021

In response to a recent 500kV line shunt reactor high-voltage bushing failure event in a station, This article examines and analyzes the objects and protection actions after the casing is disassembled. It was found that the cause of the casing failure was caused by the arc igniting the insulating oil in the casing after the main insulation of the casing was discharged. Finally, corresponding preventive measures are proposed from the perspective of on-site operation and maintenance.
Research on the Influence of Device Thermal Equivalent Model on the Temperature Field of Infrared Hot Air Reflow Soldering
Authors: Yin Yutian , Ji Chenyang , Gong Yubing
Published: May 2021

Infrared hot air reflow soldering is an important process in SMT assembly process. The temperature field of infrared hot air reflow soldering of PCBA will directly affect the reliability of solder joints. The different simplified equivalent models have a certain influence on the temperature field of infrared hot air reflow soldering PCBA, which is mainly reflected in accuracy and efficiency. This paper studies the influence of three different thermal models on the temperature field of reflow soldering PCBA, and selects four groups of points in the same position of the three models, and comprehensively compares their temperatures. The results show that the maximum temperature deviation of the three models is as high as 7℃ in the soldering zone and 4℃ in the cooling zone, and the temperature difference is small. It can be concluded that the complex solder ball model can be used for high precision applications, and the simplified single-layer solder model and the thermal equivalent model can be used for low precision applications. These conclusions provide some references for the modeling of infrared hot air reflow soldering.
Research on Energy Management Strategy of Vehicle Fuel Cell-Battery Hybrid Energy System Based on GT-SUIT/Simulink
Authors: Ji Chuanlong , Qiu Liang , Zheng Zhiqiang , Zhang Yan
Published: May 2021

Aiming at a fuel cell electric vehicle, this paper establishes a fuel cell electric vehicle power system simulation platform based on GT-SUIT and Simulink, and proposes a rule-based energy management control strategy. Under the selected European Driving Cycle (NEDC), the simulation results show that the control strategy can effectively distribute energy between the fuel cell and the battery, and meet the power demand of the vehicle. The SOC of the battery is always kept in a reasonable range.
On Signal Surveillance Analysis of Vibration Fault of Main Fan
Authors: Liang Yiyong
Published: May 2021

The research idea of the coal mine main fan’s fault diagnosis is generally the surveillance of the vibration state of the main fan’s impeller and the drive motor’s rotor. The vibration characteristics under different faults are obtained to distinguish the fault categories by analyzing the obtained vibration signals.
Structure optimization design of forging hydraulic press
Authors: Wang Xiaoying
Published: May 2021

In order to improve the centring and production efficiency of punching, we can add a centring structure to improve the centring of forgings in the punching process, which is mainly used to ensure the correct position of forgings during upsetting and punching, that is, to ensure the center of forgings and the center of hydraulic press to coincide. At the same time, a swing punch structure is added to clamp the replaceable punch, which is mainly used to ensure that the center of the hydraulic press coincides with the center of the punch, and there is no need for manual or auxiliary machine in the working process of the swing punch structure, which can greatly improve the production efficiency.
Design of NB-IoT smoke sensing terminal based on photovoltaic and supercapacitor power supply
Authors: Liu Yiming , Miao Fengjuan , Su Wei , Yang Le , Li Xue
Published: May 2021

The common smoke detection terminal designed for fire detection is mainly based on wireless communication technology and sensor technology. With the development and application of 5G technology in recent years, the Internet of Everything will become a historical inevitability. Compared with the traditional wireless networking technology, the application of NB-IoT technology can greatly reduce the power consumption and cost of the equipment, and also increase the service life of the equipment. Under the background of more and more mature communication network technology in the future, how to make the equipment more durable and lower power consumption has become one of the key issues to improve the performance of the equipment. Therefore, the power equipment charging with polycrystalline silicon photovoltaic cells and storing energy with supercapacitors can supply energy for the detection equipment continuously. The photovoltaic charging circuit uses the variable step length conductance increment method to track the maximum power point to improve the utilization rate of solar energy. As a communication technology, narrow-band IoT can reduce more power consumption. The narrow-band bandwidth allows devices to be widely placed in a fixed area. Under the premise of realizing the functional requirements, the principle of hardware and software design is mainly to realize the low power consumption in all aspects, and the design of the upper computer is mainly to realize the real-time understanding of the detection equipment.
Discussion on the Research of GFRP Anti-floating Anchors
Authors: Cao Yingqian
Published: May 2021

As a kind of anchor to deal with the anti-flotation problem of floor, anti-flotation anchors have many advantages, such as strong adaptability to stratum, high anchoring force, low cost, short construction period, small stress at single point, simple construction and low cost, compared with the traditional anchor. In recent years, it has been more and more applied to solve the problems of foundation pit supporting and foundation floor anti-floating in the construction process of buildings. In this paper, the stress and strain distribution law, load transfer characteristics and the relationship between GFRP anti-floating anchor and rock mass of GFRP anti-floating anchor are summarized, and suggestions for the future development of GFRP anti-floating anchor are put forward.
Optimized Design Based on FSC Racing Wheels and Brake Discs
Authors: Pan Jialun , Wu Siyu , Huang Yanyang , Li Boyang
Published: May 2021

As we all know, there are many factors that affect the lap time of a racing car, and the performance of the braking system is an important part to ensure the delayed braking and driver safety. In this paper, we plan to design a wheelside braking system for FSC racing cars through CATIA, ANSYS and other modeling and simulation software, and verify the reliability of the design through calibration and calculation for various working conditions. to ensure that the brake system can function properly under extreme conditions.:
Research on foldable coupler device of modern tram
Authors: Yang Bo , Liu Huanjun , Yin Jun
Published: May 2021

This article introduces the basic requirements of the coupler buffer device of modern tramcars, gives a detailed description of the new type of folding coupler type, structural parameters, and principle of action. At the same time, the compression and tensile strength analysis of the main stressed parts of the foldable coupler after the lightweight structure design transformation carried out through finite element, and the analysis results meet the design requirements.
Gantry type rotating platform obstacle avoidance crane
Authors: Zhang Yu , Chen Yun
Published: May 2021

The rapid development of modern logistics industry has higher requirements for logistics machinery and equipment. As an important equipment for material handling, cranes are used more and more widely in the modern production process. At present, cranes have problems such as large size, inconvenient movement, and inaccurate positioning. Based on the above background, the project team designed a gantry type rotating platform obstacle avoidance crane. The crane breaks through the transportation limitations of the original crane. It uses the direct rotation of the pan-tilt and the movement of the spreader on the track to accurately avoid obstacles, which improves the flexibility and accuracy of transportation; the entire transportation process is fully automatic control, which combines the machinery with The combination of intelligence improves transportation efficiency and realizes the accurate transportation of multiple goods.
Microstructure analysis of P91 heat resistant steel in service for 3 years
Authors: Ren Facai , Xu Jinsha , Tu Zhiqiu , Si Jun
Published: May 2021

P91 heat resistant steel is an important material for supercritical units. In this paper, a P91 heat resistant steel pipe which has been used for about 3 years is analyzed by means of hot tensile test, metallography and scanning electron microscope. The results show that the microstructure is martensite and a large number of Cr-rich precipitates are distributed at the grain boundary. There are pores and cracks in the fracture of high temperature tensile specimen.
A distributed energy equipment with highly efficient heat dissipation
Authors: Wang Zhongyu , Liu Peichen , Jiang Qiushuo , Wan Yi , Yang Chengcheng , Wang Xu , Liang Jiachen
Published: May 2021

Distributed energy technology is an important development direction of the world energy technology in the future [1]. It has the characteristics of high energy utilization efficiency, small negative impact on the environment, improving the reliability of energy supply and good economic benefits. At present, China’s distributed energy technology is not mature enough. Aiming at the heat dissipation problem of distributed energy technology, we propose a method of using natural rainwater air cooling to realize the efficient heat dissipation of distributed energy equipment. It provides a reference for the development of distributed energy technology.
Research on Road Landscape Scale Design Based on the Neural Network Algorithm
Authors: Chen Hua , Shang Yan
Published: May 2021

There had high traffic accidents rate in China. The accident rate was on an upward trend every year. The cause of the accidents frequently occur, including the driver’s driving level, the safety performance of the car and the design of the road landscape scale. Therefore, in order to reduce the accident rate, this paper presented the research of road landscape scale design based on neural network algorithm to reduce the accident rate. The scale of the landscape was designed by neural network algorithm, and then transforming variables, size and other design elements were processed. The paper had selected the road as a pilot at random, with the most humane scale design as the standard for regional design investment. Through comparing the monitoring of pilot locations, we found that the rate of traffic accidents had been effectively reduced.
The Design of Unmanned Retail DIY Beverage Machine
Authors: Gai Kerong , Li Miao , Zhou Fengying
Published: May 2021

Intelligent technology has begun to replace humans with multiple scenes. This paper discusses a sort of intelligent device which is based On the integration of double cooperative robot arms, double capsule machine and other components, to achieve the design of personalized unmanned production and sales of 20 kinds of drinks. The device utilizes the cloud order system and unmanned retail technology to realize the de-artificial online and offline 24 hours uninterrupted multi-beverage customization service.
Mechanism design and simulation analysis of robot system for vascular interventional surgery
Authors: Yu Haoyang , Wang Hongbo , Liu Wenjie , Niu Jianye , Huang Da , Yang Xue , Dong Yu
Published: May 2021

At present, the mortality of cardiovascular and cerebrovascular diseases is getting higher and higher, interventional surgery has obvious advantages over traditional surgery, and robot technology has also entered this field. Combined with the existing research results, a set of surgical robot system is designed. The operating device uses magnetic powder brake to provide real force feedback of braking torque, the propulsion device adopts a clamping rod structure to accurately clamp the catheter or guide wire, and the force signal is collected by using the lever principle. Finally, the study of the dynamic characteristics of the propulsion device shows that the smaller the quality and the higher the tension force are, the more favorable the performance of the propulsion device is, and the calculation verifies the rationality of the transmission part of the propulsion device.
Design of an Asymmetric Multistage Depressed Collector for K-Band 100W Traveling Wave Tube
Authors: Bao Hailong , Tang Kangsong , Cao Linlin , Su Xiaobao
Published: May 2021

Efficiency and back-streaming current are important indicators in a traveling wave tube (TWT). A new asymmetric multistage depressed collector (MDC) is needed when designing a K-band 100W space TWT for high collector efficiency and low back-streaming current. In the new collector, the second, third, and fourth electrodes are asymmetrically designed to form an asymmetric electric field, and the potential and geometry of the electrode are appropriately optimized. The simulation shows that when the electronic efficiency is 27.28%, the collector efficiency is 85.34% with zero back-streaming current.
Optimization Design and Analysis of All-terrain Vehicle Based on Modal Analysis
Authors: Pan Keqiang , Zheng Weizhong , Shen Xin
Published: May 2021

Under a certain stiffness and strength, the dynamic characteristics directly affect the stability and off-road quality of the all-terrain vehicle (ATV) when driving on complex terrain. With the innovative design of ATV, the 3D model and the finite element analysis model are established. Based on the static analysis, ANSYS analysis software is applied for the body modal simulation analysis, aiming at reducing the body deformation and improving the low-order natural frequency of ATV. By comparing the influence of the finite element modal analysis results on the dynamic characteristics and stiffness characteristics of the ATV under typical conditions, the weaknesses of the structural design are pointed out, which provides the research basis for the further improvement and technical upgrading of the prototype.
A design scheme for harmonic suppression network of high efficiency class-F power amplifier
Authors: Liu Chengxin , Chen Xiaolong
Published: May 2021

This paper presents a design scheme of class-F PA harmonic suppression network. This scheme combines the advantages of lumped parameter elements and distributed parameter elements, and makes use of the characteristics of high Q value (quality factor), large adjustability of capacitance and high reusability of the microstrip line, so that the harmonic suppression network has the advantages of them. Based on the proposed scheme, a class-F PA with a frequency of 2.4GHz and a maximum PAE of 68.86% is designed, the output power of which can reach 17.5W (42.42dBm), so as to verify the feasibility of the proposed scheme. This scheme can improve the output power of UHF (300 ~ 3000MHz) class-F PA and reduce the difficulty of circuit design under the condition of high PAE.
Research on a New type of Wiper Assembly Based on New Energy Vehicle Electrical System
Authors: Deng Qingjun , Li Peipei , Zhao Yi , Liu Yong , Hu Jianyu , Song Shijie
Published: May 2021

This paper analyzes the research status of commonly used wiper assembly. It propos es a wiper assembly which is applied to new energy vehicles. Moreover, a new set of wiper ass embly device is developed and the hardware design and software programming of the device h as been accomplished. This device is used to test the cleanliness and noise of the front windshi eld of a car. And the test results are presented. The test shows that the device has stable perfor mance, simple operation and it meets the cleaning requirements of new energy vehicles. This p aper provides technical support and technical reference for the research and development work of new energy vehicles and electronic parts enterprises.
Design and Application of Temperature Monitoring System for Dangerous Goods Container Yard
Authors: Wang Mingchao , Meng Guodong , Zhao Xin
Published: May 2021

Container shipping of dangerous goods can effectively reduce the damage rate of dangerous goods. However, due to the physical and chemical properties of dangerous goods, such as flammability, explosiveness, and corrosion, there are many safety matters that need to be paid attention to when the containers are stored in the yard, especially the temperature. In this paper, a temperature monitoring system (short for TEMP Monitoring System) is developed for the temperature monitoring needs of the dangerous goods container yard. The system is composed of a temperature sensing terminal, a repeater and a terminal processor, which can monitor the temperature of the yard container in real time and effectively improve the level of safety supervision.
Application of Artificial Neural Network in Course Design of Safety System-Taking a rail transit operation safety evaluation as an example
Authors: Chen Jianhua , Xu Haoming , Gao Wei , Gao Jingsheng
Published: May 2021

In the course design of safety engineering, artificial neural network was adopted to assess the operation safety of the urban rail transit system by using the generalized regression neural network. By comparing the evaluation values with the scores graded by the experts, the results indicated that predictions by using the generalized regression neural network had the better performance. Therefore, the GRNN was capable of evaluating and predicting the operation safety of the urban rail transit system.
Study on the design method of interference fit between gear and shaft of automobile transmission
Authors: Li Shuge , He Zhangtao , Zhao Pengju
Published: May 2021

The interference fit of gear and shaft in automobile transmission has an important influence on the performance of gear transmission. In order to design reasonably and calculate accurately, the theoretical calculation model of the interference fit between gear and shaft is established according to the principles of elastic-plastic mechanics. A new method of calculating the amount of interference is designed based on the Lame equation. Three limiting conditions are taken in the calculation. They are load transfer capacity of gear, no plastic deformation of fitting surface and control of gear tooth deformation. The theoretical calculation and finite element simulation analysis are carried out in an application case. The results of calculation and analysis show that the interference fit of gear and shaft has an important influence on the gear tooth deformation. The amount of interference calculation method in this paper can reduce the deformation of gear tooth and make the gear have higher accuracy.
Research on Credit Strategy of Small and Medium Enterprises Based on Subjective and Objective Comprehensive Evaluation
Authors: Zou Yuxuan , Zhang Yunxuan , Jiang Lintao
Published: May 2021

In order to study the adjustment of national policies on medium, small and micro enterprises, and to determine the credit risk and credit strategy of banks to medium, small and micro enterprises. Firstly, the enterprise strength and comprehensive reputation of small and micro enterprises are analyzed, and their weight is determined by the subjective and objective comprehensive evaluation method, and the credit risk factors of each enterprise are calculated. A dual objective optimization model was established and solved by simulated annealing algorithm. The optimal profit amount and annual average interest rate of banks for different industries and different categories of credit strategy are obtained. Analytic Hierarchy process and Fuzzy Bayesian network are used to explore the influence of multiple emergent factors on banks adjustment credit strategy.
A research on foot size measurement algorithm based on image
Authors: Wang Huawen , Liu Fuchang , Fan Ran
Published: May 2021

Foot size measurement has a wide range of applications. It can not only be used in medical foot health, evaluate the health index of the foot, improve the health of the human foot, but also provide a large amount of foot data for the study of kinematics. Due to the limitations of measurement equipment and related algorithms, 3D foot measurement cannot be widely used. We proposed a fast and convenient foot measurement method based on deep learning and image segmentation algorithms. The HED model is used to detect the edges of A4 paper; the traditional image segmentation algorithm GrabCut is used for segmentation of the foot area. The results show that the algorithm proposed in this paper has a faster measurement speed and higher accuracy for foot size measurement.
Linear Regression Model of Railway Passenger Traffic Volume and Its Influencing Factors
Authors: Zhang Yue
Published: May 2021

The railway is one of the most crucial transportation modes in China and plenty of people choose to travel by railway. Finding the influencing factors of passenger traffic volume of the railway can help us to develop the railway construction. Substantial research has probed factors influencing the railway passenger volume and has identified several influencing factors. In this study, we try to find a long-term relationship between passenger traffic volume of the railway and six influencing factors, which are total population, employed persons, number of national railway passenger coaches owned, GDP, and household consumption expenditure. In order to find long term relationship models, we collected the data of r passenger traffic volume of the railway and other six influencing factors from 1978 to 2019. By developing several multiple linear regression models, we can see that all of these six factors can impact the passenger traffic volume of the railway and the model of six factors can describe the relationship well. After simplifying the model with six factors, we find two more models that can describe the relationship with less influencing factors, which are y = 1.059 × 105 - 1.773 × 10-2
x
1 + 2.729 × 10-1
x
5 + ε and log(y) = 11.5-3.309 × 10-8x1+1.435 × 10-6x5+ε. Using the diagnostic plots to analysis these two models, we find that log(y) = 11.5-3.309 × 10-8x1+1.435×10-6x5+ε is better. According to the model, GDP and traffic volume are two main influencing factors on the railway passenger volume. We use this model to predict the railway passengers in 2019 and compare the predict value with the data. The error rate i 5.4688% and we believe that this log(y) model can also be used to predict the railway passenger volume.
Improvements of YoloV3 for road damage detection
Authors: Wang Qinglang , Mao Jingchao , Zhai Xu , Gui Jie , Shen Wenjie , Liu Ye
Published: May 2021

Automatic detecting road damage from images is a challenging problem. Recent advances in deep learning based detectors offer a powerful tool for resolving this problem. However, these deep learning detectors are designed for detecting generic objects, the specific characteristics of road damage are not considered in these methods. We propose in this paper an improved method based on YoloV3 that takes in consideration the slenderness and tininess nature of the road damage, which require low-level and detailed description. Our method fuses the low-level feature with high level feature to enhance the description power of the network, and also an improvement to the loss function further boosts the detection performance. Experimental results have demonstrated the effectiveness of proposed method.
Diffusion of nano-rods
Authors: Ma Fu , Wang Zhihai , Wang Yaohong
Published: May 2021

Diffusion behaviors in nano-rods suspension in the fluid are investigated by Stochastic Eulerian Lagrangian Methods, where the degrees of freedom for coarse-grained microstructure are coupled with continuum stochastic field to capture both the relaxation of hydrodynamic modes and thermal fluctuations. The diffusion characteristics of a single rod and multi-rods are examined with hydrodynamic interaction in three dimensions. For a single rod, the mean square displacement is verified by comparing with prior experimental results. The effects of hydrodynamic interactions on the translational and rotational diffusivity with different aspect ratios are represented by velocity auto-correlation function and the orientational auto-correlation functions. For multi-rods cases, we obtained their diffusion in the ballistic and the short-time regime. The comparison between the SELM and the Langevin method confirms the hydrodynamic effect.