bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of terrain navigability in underwater terrain aided navigation
Authors: Zhao Miao , Xu Zhenyang , Weiqiang MA
Published: June 2021

Aiming at the problem that the single terrain characteristic parameter cannot comprehensively evaluate the terrain navigability of the matching areas, the weighted vector correlation degree is introduced, and the terrain characteristic parameters such as the standard deviation of terrain elevation, roughness, correlation coefficient, terrain information entropy and terrain slope are comprehensively considered. A multi-index comprehensive decision-making evaluation method based on grey fuzzy theory is proposed. In addition, aiming at the problem that different matching routes have different navigability for the specific terrain, in order to select matching routes with better navigability, a navigation coefficient based on terrain statistical parameters is proposed to analyze the navigability of different routes. And the point mass filter (PMF) algorithm is used to simulate the navigability of the matching areas with different terrain features and matching routes. The simulation results show that the proposed evaluation method and navigation coefficient are feasible in the evaluation of terrain navigability. The stronger the navigability is, the smaller the matching error is and the better the navigation performance is. This research results can provide theoretical basis for analysis of terrain navigability, selection of matching areas and matching routes planning in terrain aided navigation.
A Simulation Study on the Optimization of Flow Channel Pattern in High Temperature Proton Exchange Membrane Fuel Cell
Authors: He Zhao , Luo Xiangyi
Published: June 2021

High temperature proton exchange membrane fuel cell (HT-PEMFC) has been one of the most promising candidates for the power source of vehicles. Correspondingly, as a factor significantly influencing the performance of the HT-PEMFC, the structure of the flow channel has been extensively discussed. In this study, the multi-channel flow patterns of fuel cell was proposed, and the effect of the channel number on the fuel cell performance was investigated by numerical simulations. The results showed that the HT-PEMFC with multi flow channels performed a power density of 0.392 W cm-2, better than that of single-channel fuel cell. Furthermore, after a comprehensive consideration of performance and production cost, the bipolar plates with three flow channels is recommended. It is noted that the as-designed flow pattern contributes to the improvement of the HT-PEMFC power density.
Demand Factor Forecasting Method of Design for Communication and Signal Building Electric Systems by Kernel Density Estimation
Authors: Xiong Wei
Published: June 2021

With the expanding high-speed railway construction scale, the loads along the railway are gradually transformed into electrification, and capacity level of power distribution system of high-speed railway is increasing. The power system for communication and signal loads along the railway is one of the important parts of guaranteeing the reliable operation of the high-speed railway. However, at present, there is no unified standard for transformer capacity design in the electrical design of communication signal building., resulting in the theoretical value of transformer capacity design inconsistent with the actual engineering requirement. To address the problems and formulate a more accurate design standard for the communication and signal building, the load demand factor forecasting of communication and signal building based on based on kernel density estimation with optimal window width is proposed in this paper. Firstly, the topology of the high-speed railway power system is introduced and the principle of demand factor is proposed. Then, the kernel function selection and the optimal window width of the algorithm is proposed to adapt to the estimate the demand factor based on massive samples. Lastly, the experiment is conducted in the trial operating-high-speed railway, the correctness of the forecasting demand factor is verified. And the results are applicable as the reference for electric design of the power loads in high-speed railway in the future.
A novel intestinal diagnosis system based on inchworm-like micro robot with wireless power transfer
Authors: Han Ding , Yan Guozheng , Wang Zhiwu , Jiang Pingping
Published: June 2021

A novel intestinal diagnosis system based on inchworm-like micro robot with wireless power transfer have been proposed in this study. The micro robot has been minimized in size to Φ 14mm in diameter, like a capsule. It can be swallowed in without pain. Furthermore, the expanding mechanism and telescoping mechanism make it possible to possess bidirectional motion and stable anchorage. Powered by wireless power transfer system, though receiving coil is embedded in a limited space, it also supplies enough power 653mW for micro robot system after optimization. In addition, wireless communication and human machine interface system is used to capture the video image in intestine. At last, some in vitro experiments are conducted with prototype in a porcine intestine. Under the optimized wireless power transfer system, with transmission efficiency 4.66%, the communication error rate at 1m distance is just 0.7%. The speed of micro robot in the viscoelastic and slippery intestine could reach 4.38 cm/min. And operators can obtain images inside the intestine by the human machine interface system in real time. All of the above show a good performance of the proposed intestinal diagnosis system based on inchworm-like micro robot with wireless power transfer.
The simulation of a service robot for task planning
Authors: Cui Guowei , Shuai Wei , Chen Xiaoping
Published: June 2021

This paper introduces a simulation for service robots based on Robot Operating System (ROS) and Gazebo. It aims to test and evaluate task planning algorithms. After building the environment and the service robot model, a 2D map is built. To make use of semantic navigation, we construct a topological map from the 2D map. Several functions are written to realize the robot’s necessary actions, including navigation, grasping, placing, handing over, and searching person/object. Answer Set Programming (ASP) is used for planning; due to its complicated coding and poor legibility, we define an easy to understand format and translate it into ASP. Finally, we test our task planning system within the uncertain Gazebo environment. The experimental results show the usability of the simulation for task planning tests.
Generalized Attitude Model Identification of a Quadrotor
Authors: Qin Qiao-Hui , Liu Jin-Cang , Geng Li-Hui
Published: June 2021

This paper studies the generalized attitude model (GAM) identification of a controlled quadrotor by using flight experimental data. The GAM describes the dynamics of the quadrotor and its driving motors. Its mechanism analysis will be first carried out for guiding the parametrization of its estimation model. Before the prediction error method (PEM) is applied on the GAM identification, the involved closed-loop identifiability problem is addressed. Finally, the accuracy of the estimated GAM is validated by comparisons of Bode diagrams and controller performances achieved by a redesigned robust controller.
Multy-modality Switch Modeling and Simulation of A Three-port DC-DC Converter
Authors: Liu Jinghui , Liang Yongchun , Shen Guowang , Cheng Qing , Zhang Shilong
Published: June 2021

A three-port DC-DC converter (TPC) for photo-voltaic (PV) electric vehicle (EV) was presented in this paper. A PV module and a battery consist of the power supply for electric vehicle. A boost converter helps the PV module to output maximum power. A sepic-zeta converter helps the battery to be charged by PV power or output power for EV. A cuk converter was used to keep the stability of output voltage for load. There are five modalities for the TPC model and three applications were simulated to verify the performance of different modality switching. The simulation results show that the given TPC model have some advantages, such as small steady errors, short transient times and small fluctuation of voltage and power. This TPC can be used in EV to provide a steady voltage for motor and extend the driving distance.
Analysis of Single-phase Grounding Fault with Distributed Generation in Distribution Network
Authors: ZhuoLin Chen , YuanChun Tang , WenQin Lin
Published: June 2021

Different distributed generation (DG) types and neutral grounding methods affect single-phase ground fault current characteristics of distribution network. To analyse the single-phase ground fault current characteristics, this paper establishes a single-phase ground fault model with rotating and inverter-type DG accessed using symmetrical component method. By considering different grounding methods of distribution bus side and DG side, distribution characteristics and change laws of fault current as well as sequence currents on both sides of fault point when single-phase short circuits occur in different positions of system are discussed. To verify correctness of analysis, simulation experiments of models is carried out by Simulink. The results of this paper can provide reference for system relay protection configuration and neutral grounding method selection.
Calculation and Analysis of Induced Current in Optical Fiber Composite Overhead Ground Wire
Authors: Yifeng Fan , Xingzhou Li , Chengyuan’ Liu , Yihang Jing , Xudong Li
Published: June 2021

In this paper, the mechanism of electromagnetic induction current of overhead ground wire is analyzed, the models of overhead ground wire with different voltage levels are established on ATP-EMTP, the electromagnetic induction current of optical fiber composite overhead ground wire (OPGW) is calculated, and the factors affecting the induced current on OPGW are analyzed, including the change in loads of transmission lines, the value of grounding resistance and the location of lines. The results of this paper provide a reference for the actual measurement and the use of this induced current for induction power supply.
Comparative Analysis of FINFETS and MOSFETS
Authors: Shao Chen
Published: June 2021

This paper makes a brief introduction of CMOS technology and illustrates the structure of traditional MOSFETs and Fin-FETs and their developing process. To help better understand advantages and drawbacks of both two technologies, it also explains the Drain Induced Barrier Lowering (DIBL) effect and its impact on transistor performance. The paper compares the DIBL ratio of Double-Gate Fin-FETs and Double-Gate MOSFETs by varying channel length using Fin-FET and MOSFET in similar structural parameters. The results are shown in different diagrams, which proves that Fin-FETs have a better control of DIBL effect than conventional MOSFETs. In the end it explains the shortcomings of the experiment and describes future expectations for Fin-FET technology.
A Brief Review of Smart Control of Renewable Energy Power Generation
Authors: Xiao Yu , Xia Chunni , Cai Qinqin , Zhu Yongqiang
Published: June 2021

The smart control strategy in the operation of renewable energy station is of great significance to alleviating the shortage of fossil energy, improving the efficiency of renewable energy utilization and the safe operation of power system. Firstly, this paper took the renewable energy stations represented by wind and solar energy as the research object, summarized the smart control strategy of single unit power generation, and elaborate introduced the mechanical structure control, maximum power point tracking control and virtual synchronous machine control in electrical converter level. Secondly, the self-protection control of renewable energy power generation station in the case of power system faults were analysed. The key issues involved in the low voltage ride-through, high voltage ride-through, protection circuit of rotor side, stator side and converters were summarized. Thus, a brief overview of smart control of renewable energy station operation is presented in this paper, hoping to provide technical guide for prosperous development of renewable energy in the future.
Research on Magnetic Field Characteristics in DC Yard of Dinghai Converter Station Under Monopolar Grounding Fault
Authors: Bao Meng , Shen Hong , Li Jialiang , Huang Xianrui , Wang Qian
Published: June 2021

In Dinghai converter station of Zhoushan VSC-HVDC transmission project, 200 kV hybrid DC circuit breaker is used for the first time to realize DC side fault isolation. When DC side short circuit occurs, its fault current characteristics are different from those of AC substation and HVDC converter station, and the magnetic field interference to secondary equipment in DC yard is still unknown. In this paper, taking the single pole grounding short circuit fault with high probability in flexible DC power grid as an example, the electromagnetic transient simulation model of fault current in Dinghai converter station is established, and the time-domain current waveform is obtained. Then, the magnetic field calculation model of DC circuit breaker and other key electrical equipment is established, and the magnetic field of secondary equipment in DC yard is calculated based on Biot-Savart Law. The results show that the maximum magnetic field strength at the secondary equipment is 59 A/m, the waveform is ms level, and it is aperiodic. The distribution of magnetic field in DC yard varies between 3 and 346 A/m.
Research and Implementation of a Local Modification Method of Power System Topology Suitable for Large Power Grid Training Simulation System
Authors: Yang Xiaojun , Zhou Lijun , Wang Ruiqiang , Zhao Chengjie , Sun Xiaodi , Gao Feng
Published: June 2021

This paper proposes a local topology correction method for large power grid simulation. The analysis method of the local topology corresponding to the “open” and “close” events of the power equipment and the correction method of the corresponding node admittance matrix. This method is suitable for online analysis systems such as large power grid simulation systems. Finally, this paper verifies that the local topology correction method proposed in this paper greatly improves the topology analysis speed and calculation efficiency of the large power grid training simulation system.
Bidirectional Virtual Inertia Control Strategy for Interlinking Converter in Hybrid AC/DC Microgrid
Authors: Ma Zhen , E Lin , Deng Hongyuan , Wang Zhi , Zhu Yongqiang
Published: June 2021

The AC/DC hybrid microgrid can realize the power flow between the two sub-microgrids by controlling the interconnected converters connected to the AC and DC sub-microgrids, thereby improving the system’s ability to suppress power fluctuations. In order to achieve a reasonable power flow between the two sub-microgrids in the steady state and in the transient process, this paper analyzes that the traditional droop control of interconnected converter ( ILC ) pays less attention to the transient process of the hybrid microgrid. On the basis of virtual synchronous generator, a bidirectional virtual inertia control strategy for ILC is proposed. This control strategy can not only respond to the offset between the DC bus voltage and the AC frequency, but also achieve the goal of sharing the system power fluctuations between the two sub-microgrids in the steady state according to the voltage and frequency offset requirements. It can also respond to the DC bus voltage and The rate of change of the AC frequency realizes a reasonable inertial support between the two sub-microgrids in the transient process. In order to balance the transient target and steady-state target of the interconnected converter, this paper designs the parameters of the proposed control. Finally, a simulation model was built in PSCAD to verify the effectiveness of the proposed control strategy.
Electromagnetic design of high-speed permanent magnet synchronous motor for flywheel energy storage system
Authors: Wu Jiabin , Xu Zhenyao , Zhang Fengge , Tong Ningze
Published: June 2021

Flywheel energy storage system (FESS) has significant advantages such as high power density, high efficiency, short charging time, fast response speed, long service life, maintenance free, and no geographical environment restrictions. Motor is the energy conversion core of FESS and plays a significant role on system performance. In this paper, the design features of the motor for FESS are analyzed first. Then, a permanent magnet synchronous motor (PMSM) with a rated speed of 12000 rpm and a rated power of 250 kW is designed. Thirdly, aiming at the key problem of difficult heat dissipation of rotor, an improved rotor structure with “1” rotor permanent magnets layered and divided where placed in tangential and radial directions is proposed, which can reduce eddy current loss by 22.8%. Finally, based on Ansys FEM software, electromagnetic characteristics of the designed motor at no-load and full-load conditions are simulated and analyzed. The results show that the designed electromagnetic scheme meets the expected performance requirements and has guiding significance for prototype.
SFRA Test Method Application for Turbo Generator Rotor Winding
Authors: Mubarak Zakky , Supriyanto Eko
Published: June 2021

The development of technology in the present makes the testing method for analysis to know the defect to insulation winding in rotating machines is varied. There are many specific testing tools to determine the damage. The authors of this paper conduct a preliminary study using sweep frequency response analysis (SFRA) to detect and find damage in the turbo generator rotor winding. SFRA is a test equipment performed on transformers based on the working principle of RLC which are Resistive, Inductive, and Capacitive. The importance of the damage identification process is needed to maintain reliable rotor generator and avoid catastrophic defect to equipment and losses to power plant. In one case study, the rotor generator experienced high vibration indication when operating in high reactive power and the SFRA test results on the rotor winding shows a mismatch between two curves. In another case, a mismatch of SFRA result showed winding deformation, such as coil elongation, without high vibration indication in rotor generator. After inspection, repair, measurement and testing, the SFRA method proves that it can show indications of defect without major dismantling.
A Fast Calculation Algorithm of Efficiency Map of Permanent Magnet Synchronous Machines Using Finite-element Method
Authors: Li Wei , Liang Hongwei , Liu Jun , Zhang Wenhao
Published: June 2021

A fast calculation algorithm of efficiency map of permanent magnet synchronous machines using finite-element (FE) method is proposed in this paper. The control strategy of the machine can be taken into account in the whole torque-speed operating region. The optimal current vector is obtained by using analytical calculations, where the material saturation is also included. By using the proposed method, only one run of time-stepping FE analysis is required below the rated speed. The calculation time of the efficiency map is much reduced compared to the conventional calculation method. An example is tested, and calculation results are given to verify the proposed method.
Picturing the thermodynamic universe with Frida Kahlo
Authors: Pereyra M , Botasini S , Cerdá M F , Méndez E
Published: June 2021

Bringing arts to the science classes remains as a challenging idea. The illustration of a concept with an original painting would bring unexpected advantages. Here we present the use of a painting of Frida Kahlo to illustrate the concept of the thermodynamic universe the surroundings. Such concept is not deeply treated in most textbooks, and it is essential now of analysis of a thermodynamic system. Because of the use of this visual aid, our students were able to distinguish several possible thermodynamic universes, depending on the objective of their study, gaining a more insightful approach than that usually obtained with classical pictographic representations in physical chemistry textbooks.
Determination of corrosion products for steam and flue gas injection environments using thermodynamic simulation
Authors: Moreno J , Santos L , Orozco-Agamez J , Ariza C , Muñoz S , Peña D
Published: June 2021

Thermal recovery processes using steam injection with combustion gases (flue gas) have shown positive results in the recovery of heavy crude oil over the conventional process, by integrating different recovery mechanisms. However, under the operating conditions, the injection of these fluids generates highly corrosive environments that have an impact on the deterioration of the materials, resulting in risks and operational costs. Therefore, it is necessary to determine the theoretical corrosion products that can be generated in these processes. This research focused on the study of API N-80 carbon steel exposed to a steam and flue gas atmosphere, at pressure and temperature conditions in the ranges of 800 psia - 1100 psia (55 bar - 75 bar) and 520 °F - 560 °F (270 °C - 290 °C) respectively. Based on this environment, to determine the theoretical corrosion products, a thermodynamic simulation stage was developed using HSC Chemistry software, which was used to generate Pourbaix, Ellingham and thermodynamic equilibrium diagrams. It was found that the main theoretical corrosion products corresponded to oxides, carbonates, and hydroxides, among which the significant presence of iron (III) oxide (Fe2O3), iron (II, III) oxide (Fe3O4) and iron carbonate (II) (FeCO3) was corroborated.
Fatigue study on AISI/SAE 1015 steel with shot peening under corrosive environments
Authors: Romero F , Pertuz A , Diaz J G
Published: June 2021

This work evaluates alternative four-point bending fatigue stress in 2 < pH < 4 corrosive media of AISI/SAE 1015 steel subjected to shot peening surface treatment. A tri factorial experimental design with replications was used. The intervening factors were: i) load levels, 0.96, 0.85, 0.73, 0.65; ii) corrosive media; pH2, pH4, ambient; iii) shot-peening surface treatment; without any shot peening, S230 shot peening and CW-41 shot peening, for which a total of 108 specimens were tested with a reliability level of 95% and a probability of failure of 3%. Tests were performed on a universal machine in a three-point bending assembly with an electro-pneumatic system. The cycle counting and control were performed by a programmable logic controller. The results of the stress-life method in each one of the scenarios show that the best condition was shown in the probes with shot peening S230 and CW-41 treatment under atmospheric conditions, where the material tends to increase its fatigue behavior; the number of cycles reached 36990 and 37773 respectively. The corrosive effect of pH2 and pH4 reduced on probes without shot peening treatment with a maximum of 9862 and 8670 cycles respectively; however, for S230 and CW-41 shots, an increase in cycle number in pH2 and pH4 was evidenced, with the best result for S230 shot at pH4 with a maximum range of 21568. Likewise, the fractography analysis shows mixed fractures with fatigue failure mechanism; the characteristics found were beach marks, secondary cracks, localized oxidation (filiform, plates, pitting, stress, and compression corrosion), nucleation, microvoids, cleavage facets, intergranular and transgranular cracks.
Study case: evaluation of pallets manufactured by structural foam with polietilene from analysis by the finite element method and mechanical tests
Authors: Bayona J A , Garnica H A , Luna J L , Juzga G A , Ortiz L R
Published: June 2021

This document presents the implementation of the methodology for the evaluation of non-metallic materials, through the modeling, simulation and diagnosis of components manufactured by the high-density polyethylene injection method called structural foam, where a mixture is made between an inert gas and polyethylene of two origins: a part of recycled material and the other part of new material. This type of manufacturing is carried out for the shaping of stowage-type components, for the transport of containers of liquid substances. For the evaluation of the Stowage, a simulation was carried out from a commercial modeling software, Autodesk Inventor, based on the geometry, the mixture of materials, the attachment points and border parameters, the location and type of loads to simulate, and the different ways in which the loaded stowage would be used. After this, mechanical tests were carried out to determine the properties of the materials in their different mixtures and a feedback process of the finite element model was carried out, thus obtaining results with a minimum error factor, and thus issuing a diagnosis, focused on which material mixing ratio was the most suitable, based on the critical points of the stowage, its stress and deformations, and its safety factor. Finally, the existence of imperfections (bubbles), typical of the manufacturing process, which tend to have an incidence as concentrators of intrinsic efforts, and as critical points, is considered.
Autoregressive modelling of chromatographic signals from urine samples for prostate cancer diagnosis
Authors: Soto-Vergel A J , Medina-Delgado B , Palacios-Alvarado W
Published: June 2021

This article evaluates autoregressive modeling as a feature extraction method in a database of chromatographic signals from urine samples for non-invasive diagnostic support of prostate cancer in response to the research question: Can chromatographic signals from urine be characterized and used as a non-invasive method for cancer diagnosis? For this purpose, a database of 18 patients, 9 diagnosed with prostate cancer and 9 control patients, is consolidated, statistical methods are implemented to generate autoregressive coefficients from the data signals, and finally, the principal component analysis technique is applied for cross-class classification. As a result, a correct classification was obtained in the total number of samples validating the autoregressive modelling as a feature extraction method in contrast to the conventional methodology usually followed in chromatographic signal processing.
Novel method for stress history analysis in normally consolidated clays
Authors: Martinez J H , Ruge J C , Rojas J P
Published: June 2021

The historical investigation of stresses in a clay material is essential to predict the compressible behaviour of a soil layer that, in most cases functions as a foundation support of superstructures. Because the stresses underwent in the geological past provide useful information to understand the response of the soil today. There are numerous methods for the interpretation of the preconsolidation stress, defined by the standard unidimensional consolidation test. The concept of preconsolidation stress is extremely useful in the geotechnical field to analyze and estimate settlements in a clay deposit, in addition to normalizing other parameters for comparative purposes. Through mineralogical analysis and consolidation tests based on different models for the estimation of the vertical consolidation coefficient, preconsolidation stress is evaluated by applying disparate constitutive methods. In order to observe the dispersion of results for a particular soil. A new technique is proposed for the determination of the preconsolidation stress prescribed in differential terms and with a high degree of objective interpretation.
Evaluation of sulfur dioxide in air quality from the emissions of vessels anchored in the Port of Rio de Janeiro, Brazil
Authors: Guimarães C S , Maia D R S , Maués C S
Published: June 2021

The navigation of waterway transport has increased significantly in the last decades in the world and Brazil contributes to this growth. Supply boat types used for logistical support the platforms demand the consumption of high-density oil for the propulsion of the main engines, auxiliaries, and boilers, which result in continuous emission of pollutants into the atmosphere, today considered one of the biggest polluters. Recent studies estimate the emission of pollutants up to 400 km from the coast, which demonstrates the direct impact on coastal communities. One way to assess the impact of these emissions is to use mathematical models that allow the effects of air pollutants to be calculated on the environment and in coastal regions, being a relevant tool for planning and regulation purposes. The main objective of this work was to provide an estimate calculation of sulfur dioxide emissions from vessels that are anchored in Guanabara Bay, Rio de Janeiro, Brazil, and understand the relative contribution of this pollutant in the context of its neighborhood. After the simulations, some calculations obtained were compared with the values monitored in nearby region, in order to estimate the contribution of sulfur dioxide emission in this region. The estimated contribution of sulfur dioxide in the evaluated region, varied from 1% to 80% from the comparisons with the monitored data.
Diagnosis of physical conditions for the implementation of a reverse logistics management model in a supply chain
Authors: Garzón-Agudelo P A , Palacios-Alvarado W , Medina-Delgado B
Published: June 2021

The objective of this research was to structure a Reverse Logistics Management model applied to the furniture sector in the city of San José de Cúcuta, Colombia, based on the identification and analysis of the current business practices adopted by the companies that are part of this sector. For this purpose, engineering methods and techniques were used to propose alternatives that contribute to achieve a competitive growth, a better use of resources and environmental impact through strategies for the reuse of products or materials that, based on their physical properties, represent the best feasibility conditions. The type of research used was descriptive, with a qualitative approach. The methods used for data collection were mainly surveys, interviews and direct inspection of the companies studied, which made it possible to evaluate the physical variables of the object of study. It was possible to demonstrate that furniture manufacturing companies can adopt better reverse logistics practices in the manufacturing processes through referencing and articulation with strategic allies in the distribution channels. It was possible to establish the importance of implementing this model as a strategy to diagnose physical conditions and improve production systems to achieve a more efficient use of physical manufacturing resources.
Design of sitting lower limb rehabilitation training robot
Authors: Nan Qin
Published: June 2021

Based on the theory of sports rehabilitation medicine, aiming at the needs of early, middle and late rehabilitation training of patients with lower limb paralysis, a sitting lower limb rehabilitation robot is designed to train muscles with impaired motor function of the limbs. The Innovative design of the lower limb rehabilitation training robot consists two parts. They are the lower limb rehabilitation mechanism and the seat auxiliary mechanism, which can restore and reconstruct the impaired motor function of patients to the greatest extent.
A extrusion die structure with four cavities in a die of Al-alloy screen frame
Authors: You peng Chen , Yu wen Deng , Gui hao Zhang
Published: June 2021

The importance of extrusion die with multi-cavities in a die was introduced, and a new die structure with four cavities in a die for the frame in the screen window of Al-alloy was presented. The selection of the structure parameters for the die were described, including the selection of the machine, the arrangement of porthole and the die hole, the optimization of parameters, the design of the chamber and the bearing belt etc. The ways of optimizing these parameters were presented. The method of checking the die strength was introduced. It was shown by the results that the structure is effective and worth promoting, and the structure can greatly improve the production efficiency and reduce costs. The aim is to extend the technology and the structure, provide reliable and valid reference data for the designers.
Research on Condition Evaluation of Gearbox Based on PCA-FCM
Authors: Wang Haitao , Fan Sixia , Wu Bin
Published: June 2021

In order to evaluate the state of the gearbox, this paper proposes to use PCA-FCM algorithm to divide the state of the gearbox. By decomposing the vibration signal of the gearbox and taking the principal component, the state of the gearbox is divided. At the same time, this paper considers the fuzzy partition and geometric structure partition of the data set to determine the classification, which is verified by the wind turbine gearbox simulation experiment platform. The experimental results show that the gearbox state assessment based on PCA-FCM algorithm can effectively divide and identify the operation state of the gearbox, which makes the operation state division of the gearbox more scientific, and provides a theoretical basis for subsequent fault diagnosis and maintenance strategy.
A New Virtual Environment System for Large-Scale Complex Products Assembly
Authors: Xiu Tian , Yue-dong Lang , Hong-wei Wu , Ying-xue Yao
Published: June 2021

To deal with the problems of complicated process, difficult operation and low efficiency for large-scale complex products assembly, a new Virtual Assembly Environment System (VAES) was proposed, which applies Virtual Reality (VR) technology in the process of assembly planning and training. A series of key technologies were proposed, such as parallel rendering, stereoscopic display, geometrical correction, walking machine. A stereo video generator was developed to maintain real-time display and decrease costs. A geometrical correction method based on NURBS surface was presented. The system was applied in the process of satellite assembly, the result showed that it was feasible for the related research and application.
Analysis of four-edge mill modality and stress deformation based on ANSYS
Authors: Qi Liu , Haodong Xu , Jianfeng Wang
Published: June 2021

In mechanical design, we often need to use CNC machining center, in which milling cutters are our indispensable and most common processing tools, milling machines. We often use two-edged milling cutters, three-edged milling cutters, four-edged milling cutters. In order to analyze the milling cutter, we need to draw the 3D modeling of the milling cutter in UG, import the 3D model into the workbench to analyze the tool finite meta, analyze a four-edged mill, analyze whether the natural frequency will resonate with the machine tool. Find 10th-order modes, stress analysis of tools, deformation analysis. Topology optimization is carried out to enhance existing effects, reduce costs and improve efficiency.
Application of Machine Vision Technology in Garlic Planter
Authors: Chunlei Li , YueYang Li , ZhiCheng Tu , Zixiu Han , Huihui Wang
Published: June 2021

Mechanized garlic planting is a very necessary trend. At present, most garlic planters do not have the function of correcting garlic posture during the seeding process, which will greatly affect the growth of garlic seedlings [1]. This paper mainly describes how to recognize garlic orientation before garlic planting based on machine vision using Python language and LBP feature algorithm, and then correct it. This machine can accurately achieve the purpose of garlic clove scale buds facing upwards and increase the rate of positive buds.
Corossion failure analysis on cotter pins used for fittings of 500kV transmission tower
Authors: Hao Chen , Xin Du , Wei Sun , Xin Qiao , Xinai Guo
Published: June 2021

Transmission line is an important part of power system and plays a key role in the process of power transmission and distribution. As the skeleton of the transmission line, the reliability of the transmission tower is an important guarantee for the safe and stable operation of the power grid. In this paper, the corroded cotter pins of fittings used for 500kV transmission tower was investigated by means of macro-morphology inspection, chemical composition analysis, scanning electron micrograph analysis, microstructure analysis and energy spectrum analysis. The result showed that the misuse of material for cotter pins and sulfide discharged from industrial production were the main causes of corrosion of the cotter pins.
Corrosion analysis of guyed rod used for 500 kV transmission tower
Authors: Feng Tian , Hao Chen , Tao Zhang , Xinai Guo , Shi Xianda
Published: June 2021

As an important part of the guyed device of cable stayed tower, guyed rod plays a key role of preventing transmission tower from tilting and toppling. In this paper, the corroded guyed rod of 500kV transmission tower was investigated by means of macro-morphology inspection, chemical composition analysis, scanning electron micrograph analysis, microstructure analysis and energy spectrum analysis. The result showed that high content of corrosive sulfate in the soil near the leg of transmission tower was the main cause of corrosion of the guyed rod.
Error Analysis Method and Sensitivity Analysis for Linkage Transmission Mechanism
Authors: Lu Liu , Guocai MA , Xiaodong Jiang , Zhihong Cao , Wei Zhang , Ke Shang , Xin Jin
Published: June 2021

Given the linkage transmission mechanism with mutual restraint, coupling, and multi constraint conditions, due to the existence of machining errors of parts, the error accumulation in the assembly process leads to the uncertainty of position and posture. At present, there is no quantitative analysis. In this study, the small displacement torsor (SDT)method was used to describe the error variation of geometric elements, and the error transmission attribute of the joint surface was proposed by using a homogeneous transformation matrix. The error accumulation value of each assembly joint surface for the linkage transmission mechanism was analyzed by using MATLAB numerical algorithm, to predict the actual position change value of the frame caused by machining error and the sensitivity of factors affecting the assembly accuracy. The sensitivity can guide for improving assembly accuracy and optimizing technology.
Finite element analysis of the chassis in telescopic crawler crane
Authors: Bing Li , Xidong He , Jianguo Liao , Yulan Wei , Xing Luo , Siqi Li , Yongli Wang
Published: June 2021

In modern industry, crawler crane is an essential equipment. Chassis is an important component for crawler crane stability. In this paper, the finite element software ANSYS is used to establish the research model of SCC250TB crawler crane chassis. According to the stress characteristics of crawler crane, six typical working conditions are selected, and the corresponding stress nephogram is obtained through calculation. The model provides the basis for the strength and lightweight design of the crane’s chassis. It plays an important role in practical engineering projects.
Hydrodynamic and Circuit Simulation and Analysis of an Integrated Wind-wave Generator by AQWA® and SIMULINK®
Authors: Xin Yuankang , Liu Yuxuan , Zhu Guorui
Published: June 2021

The wind and the wave on the ocean are often in sync with each other. Under some extreme sea conditions, individual fans on generators will bear higher stress due to the impulse of the wave. The paper discusses the numerical stress simulation of the vertical column of the intermediate fan with and without the pendulum plate component individually and performs circuit voltage simulations of the generating parts on SIMULINK®. By analyzing the force on the fan column, we conclude that the generator may eliminate wave impulse to a certain degree through the combination of fan and pendulum structures. The generator could protect itself from the scour of the wave with the mutual protection of both the fan and the pendulum parts. The electric simulation also indicated that to receive a stable output of voltage, rectification and filtering processing on the circuit should be applied.
Investigation on Absorption and Diffusion of the Oxygen in the Asymmetric Face of the β-Silicon Carbide through the Born-Oppenheimer Molecular Dynamics
Authors: Yang Xiaocui , Zhu Nannan , Zhao Rongxing
Published: June 2021

Many methods had been proposed to process the β-silicon carbide, and the thermal oxidation-assisted polishing was considered as an efficient technique. The critical procedure in the thermal oxidation was absorption and diffusion process of the oxygen in the β-silicon carbide, especially in the asymmetric face. Therefore, the absorption and diffusion of the oxygen in the asymmetric face of the β-silicon carbide by born-oppenheimer molecular dynamics were studied. It could be observed from absorption and dissociation process of the O atom with the cell size that absorption of the oxygen in upper Si surface was fast, which was realized when the distance was smaller than 3Å. It could be observed from absorption and dissociation process of O atom with supercell size that absorption and oxidation for the Si surface was quickly, and steady oxide layer with silica was formed. On the contrary, absorption range of the C surface was smaller than that of the Si surface, and the surface recombination was more significant for the C surface. It could be calculated that the bond length of Si-O in the oxide layer was in the 1.65-1.77Å. The research products obtained in this study were propitious to reveal the mechanism in the thermal oxidation of asymmetric face of the β-silicon carbide with oxygen under ultra-high temperature.
Microstructure and mechanical properties of selective laser melted AlSi7Mg
Authors: Liang Liye , Pan Xuexin , Wang Guilan , Zhang Haiou , Zhang Hao
Published: June 2021

This paper focuses on researching the formation mechanism of mesh eutectic textures of AlSi7Mg manufactured by selective laser melting (SLM) and the relationship between the evolution of the eutectic Si structure and mechanical properties with ageing temperature. The microstructure of AlSi7Mg could be analyzed with the help of the scanning electron microscope (SEM), different thermal analysis (DTA), x-ray diffraction analysis (XRD). After a suitable heat treatment process, the strength of AlSi7Mg manufactured by SLM can surpass 440MPa. The article describes the relationship between microstructures and mechanical properties, which provides a basis for heat treatments for other researchers. The major outcome of this paper, it could help to formulate a heat treatment with high elongation or high strength for SLM AlSi7Mg. This article describes the reason for the formation of the mesh eutectic Si texture. It is believed that the fine mesh eutectic Si texture is the unique advantage of SLM technology over casting or forging technology.
Numerical Analysis Based on Oil Film Characteristics of Sliding Bearing
Authors: Congying Deng , Kai Yang , Sheng Lu , Xiang Chen , Yang Zhao , Ying Ma
Published: June 2021

Taking the finite-length sliding bearing as the research object, the Reynolds equation is solved by the finite difference method and the successive over-relaxation iteration method to obtain the oil film pressure. It is concluded that the dimensionless oil film characteristics are related to bearing eccentricity and length diameter ratio. In order to study the oil film characteristics of sliding bearing, the bearing eccentricity and length diameter ratio are taken as the research objects, and the oil film thickness, load component, attitude angle and end discharge flow are solved by numerical analysis. It is concluded that with the increase of eccentricity, the bearing capacity of oil film increases, the attitude angle decreases and the end discharge flow increases with the case of a certain length diameter ratio.
Numerical study of microplastic impact hydroforming process
Authors: Cai Sheng , Zhou Xuan , Zhu Yuzhen , Yang Shichong
Published: June 2021

Microplastic forming is a promising micro production technology with great advantages due to its excellent mechanical property, definite thermal stability and low manufacture cost. Impact hydroforming technology is a high strain rate forming method that can improve the limit of metal microplastic forming. In this study, FE-simulation is carried out to reveal the influence of different process parameters on the forming behaviors of micro impact hydroforming process. The forming depth is improved with the increase of the velocity. In addition, different areas of the formed parts are affected by the liquid pressure, bottom fillet, blank holder and friction condition. The strain distribution is inhomogeneous, and the ball head portion has the largest strain. The simulation result also shows the thinning effect is greatest at the center point and decreases from the center to the radius. Through the analysis of the process feasibility, the simulation results of microplastic impact hydroforming can provide references to the design and manufacture of actual impact hydroforming parts.
Research on piezoelectric stacked generator and its application
Authors: Duan Yuhan , Xu Jinxiang , Sui Li
Published: June 2021

In response to the energy density and fast activation requirements of small caliber ammunition fuzes for power supplies, this paper designs a piezoelectric stacked physical power supply that can generate electrical energy using the setback acceleration generated at the moment of ammunition firing as a power source. The paper designs the structure of the power supply according to the performance parameters of the selected piezoelectric materials and tests the power generation performance of the power supply using a simulated experimental setup. The experimental results demonstrate that the output voltage of the piezoelectric power supply has a linear relationship with the load. When the piezoelectric power supply charges the capacitor, the voltage across the energy storage capacitor also increases approximately with the increase of load, and the piezoelectric stacked power supply designed in this paper can meet the requirements of small caliber ammunition.
Structure design of small road snow remover
Authors: Xingzhihui  , Lijunling
Published: June 2021

According to the characteristics and degree of snowfall in Northeast China and the compaction characteristics of ice and snow on urban traffic roads, the equipment is designed according to local conditions, which can be widely used in various small area snow removal operations. The cleaning power of the machine is mainly provided by the gasoline engine. The power is transmitted to the actual rotating cleaning parts through the reducer, transmission shaft and chain transmission to complete the task. This paper briefly introduces the scheme design, structure design and parameter design of the small road snow remover.
Summary of the Prediction Methods of Tool Remaining Life Based on Data Collection
Authors: Chen Xi , Wu Jun , Zhou Tingting , Li Yunxia
Published: June 2021

According to different starting principles, this article has advanced the prediction methods of tool remaining life in FMS. It focuses on the physical model method and the method of collecting data based on specific signals and using it as the tool life prediction feature quantity. Then they showed their research status and summarized the corresponding advantages and disadvantages.
Technological Process Design for Disassembling the Joint Frame of A Certain Type of Surface-to-air Missile Co-launcher
Authors: Liu Hanchao , Wang Xuezhi , Li Shangwen , Guo Anxin
Published: June 2021

In order to better standardize the process of disassembly and assembly of a certain type of surface-to-air missile co-launcher assembly frame, improve the efficiency of bomb replacement, and shorten the preparation time for combat, this paper uses Pro/E three-dimensional modeling software to perform three-dimensional modeling of the main structure of this type of co-frame launcher, and carry out the analysis of mechanical interface adaptability.