The Journal of Electromechanical Engineering Technology
Collection of High-Quality Papers, Issue 4, 2024
20240401
Research Review on Data-Driven Optimization Methods for Laser Cutting Process Parameters
Wei Zhuo, Zhang Hong※
（Jianghan University, School of Intelligent Manufacturing, Wuhan 430056）
Abstract:
In recent years, data-driven optimization methods for laser cutting process parameters have received widespread attention and research. This paper reviews the main research progress in this field. It compares data-driven methods with mechanism-based model methods for optimizing laser cutting process parameters and clarifies the research objects of data-driven methods. The current research ideas and progress in data-driven optimization of laser cutting process parameters are summarized from the perspectives of process parameters and process quality, and the data-driven methods used in existing studies are summarized. The specific implementation means of data-driven optimization of laser cutting process parameters are outlined. The advantages and disadvantages of various data-driven optimization methods are summarized, and future research directions worth exploring in this field are discussed, including improving data acquisition and data augmentation methods, strengthening the evaluation of models and algorithms, and exploring more efficient and intelligent implementation methods.
Keywords:
Data-driven; Laser cutting; Parameter optimization
Funding Project:
Jianghan University 2022 School-Enterprise Cooperation Project
（ZH2022-116）
Author Information:
Wei Zhuo (1999—), Male, Master’s student, research area: data-driven control system modeling and optimization.
Zhang Hong (1969—), Female, PhD, Professor, Master’s supervisor, research area: fault diagnosis and fault-tolerant control of networked control systems.
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20240402
Research Review on the Development and Application of Intelligent Tire Technology
Li Hua1, Sun Xiaopeng1, Huang Liya2, Wu Liangjun1, Chen Xiang1
（1. Guangdong Communication Polytechnic, Guangzhou 510650; 2. Guangdong Foreign Language and Arts College, Guangzhou 510640）
Abstract:
Intelligent tires integrate various advanced technologies such as information technology, sensor technology, and communication technology, enabling real-time tracking and monitoring of tire conditions, preventing issues such as aging and damage during use, as well as problems with second-hand and retreaded tires, thereby reducing traffic accident rates and providing reference data for the control of intelligent connected vehicles. This paper summarizes the three main technological development stages of intelligent tires from both theoretical and applied research perspectives: the radio frequency technology stage (realizing tire identity marking and tracking), the sensor detection stage (realizing real-time monitoring of tires), and the Internet of Things and big data stage (realizing data complementarity between intelligent vehicles and tires and monitoring the entire lifecycle of tires). The basic characteristics, technical means, and main functions of these three stages are discussed, along with the opportunities and challenges faced during the development of intelligent tires.
Keywords:
Intelligent tires; Radio frequency identification; Sensor monitoring; Big data; Internet of Things
Funding Project:
Guangdong Province Characteristic Innovation Project for Ordinary Colleges and Universities
（2019GKTSCX033）
Guangdong Provincial Department of Education Youth Innovation Talent Project
（2022WQNCX134）
Guangdong Provincial Teaching Guidance Committee Project for Transportation Majors in Higher Vocational Colleges
（JTYSJZW2022B02）
Guangdong Communication Polytechnic School-level Scientific Research Project
（ZC-B-07-01KY-21030）
Author Information:
Li Hua (1990—), Male, Master’s, Lecturer, research area: new energy vehicle technology and automotive electronics technology.
Sun Xiaopeng (1992—), Male, PhD, research area: non-destructive testing technology and intelligent equipment development.
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20240403
Design of an Automated Assembly Control System for Stud Welding Based on PLC
Yan Ran, Qin Yang, Yin Qin※, Xia Lei, Zhao Qing
（Chongqing University of Technology, School of Mechanical Engineering, Chongqing 400050）
Abstract:
In the stud welding assembly process, relying solely on manual twisting by workers leads to low assembly efficiency, high error rates, and difficulty in maintaining the preset torque during assembly. To address this, an automated assembly system for stud welding was developed based on Siemens S7-1200 PLC, combined with peripheral devices such as vibrating bowls, sliding table modules, sensors, pneumatic components, and torque guns. In this system, the PLC detects whether the parts are in place through sensors to control the start and stop of the vibrating bowl, thus achieving orderly feeding of studs and bases. By controlling stepper motors, pneumatic grippers, and cylinders, the part gripping and assembly process is completed. The torque gun is controlled via Modbus TCP communication to achieve stable assembly of studs and bases at the preset torque. This method ensures high stability of stud welding components during the vehicle body welding process, improves assembly efficiency, saves a significant amount of labor, and optimizes quality.
Keywords:
Stud welding; Automation; PLC; Communication control
Funding Project:
National Natural Science Foundation Project
（52105245）
Chongqing Natural Science Foundation General Project
（cstc2021jcyj-msxmX0303）
Chongqing Education Commission Scientific Research Project
（KJQN202001147）
Author Information:
Yan Ran (1986—), Male, PhD, Associate Professor, Master’s Supervisor, research area: intelligent manufacturing, machine vision, 3D printing software and control systems, deep learning, large-scale parallel computing, etc., has published more than 20 papers.
Yin Qin (1990—), Female, PhD, Associate Professor, Master’s Supervisor, research area: digital design and intelligent manufacturing, performance testing and dynamic analysis of intelligent equipment, etc., has published more than 10 papers.
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20240404
Design of Underwater Robot Formation Ultrasonic Ranging Based on Artificial Potential Field Method
Lu Jiahui, Song Xiaoxiao, Wang Qingchun※
（Beijing Forestry University, School of Engineering, Beijing 100083）
Abstract:
During the formation change of underwater robots, it is necessary to continuously obtain distance information between the leader and followers, as well as among the followers. To solve the ranging problem, a ranging system based on a four-channel ultrasonic transducer was designed using the STM32F103RET6 microcontroller. This system consists of a microcontroller main control module, voltage conversion module, ultrasonic generation and transmission module, isolation module, front-end amplification module, bandpass filter module, back-end amplification and comparison module, temperature acquisition module, and multi-channel measurement control module. During the ROV’s movement, this system can achieve distance measurement and can correct the ranging results based on temperature to improve accuracy, assisting the artificial potential field method in achieving formation control of underwater robots. In clear water environments, tests of the ranging system were conducted at different depths, with the maximum measurement distance being 200 cm and the maximum error being 2.2 cm, indicating reliable ranging results. In formation performance tests, it was observed that the formation change was smooth and could be maintained, verifying that this ranging system meets the practical application requirements for ROV formations.
Keywords:
Multi-ROV formation; Ultrasonic transducer; Ranging; Artificial potential field method
Funding Project:
National Natural Science Foundation Project
（51475255）
Author Information:
Lu Jiahui (1999—), Female, Master’s student, research area: underwater robot positioning.
Song Xiaoxiao (1997—), Female, Master’s student, research area: underwater robot formation.
Wang Qingchun (1969—), Male, PhD, Professor, research area: vehicle structural design and mechanical performance analysis, intelligent devices, etc.
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20240405
Dynamic Plane Tracking Control Method for Robots Based on Laser Displacement Sensors
Li Yunxiang1, Zhou Shumin1, Wang Zhicheng1, Ji Zhiteng1, Zhu Qing2, Zhou Xianen2, Peng Guangrong3
（1. Donghua University, School of Mechanical and Electronic Engineering, Nanchang 330013; 2. Hunan University, Changsha 410082; 3. SANY Heavy Industry Co., Ltd., Changsha 410100）
Abstract:
To address the low efficiency and poor anti-interference of dynamic plane tracking in the intelligent manufacturing industry, manufacturers typically choose traditional vision solutions to solve this problem. However, this method has application issues such as image distortion at short distances and large pose estimation errors. Therefore, a robot dynamic plane tracking method based on laser displacement sensors is proposed. This method employs a combination of robots equipped with multiple laser displacement sensors at the end of the robot tool flange, integrating the high frequency, high precision, and high anti-interference characteristics of the sensors into the pose guidance of the robot. By combining data analysis, data processing, robot motion models, and plane tracking algorithms, real-time tracking of dynamic planes by the robot is achieved. Experiments on horizontal plane fluctuations and vertical plane random shaking were conducted, and the results show that when four laser displacement sensors are mounted at the end of the robot tool flange, the overall tracking efficiency can reach 90%, which is beneficial for improving the level of intelligence and efficiency in actual production.
Keywords:
Robot; Sensor; Dynamic plane tracking; Trajectory planning
Funding Project:
National Natural Science Foundation Project
（62103142; U21A20482）
China Postdoctoral Science Foundation Project
（2020TQ0090; 2020M672485）
Author Information:
Li Yunxiang (1999—), Male, Master’s student, research area: machine vision and intelligent robot applications.
Zhou Shumin (1971—), Male, PhD, Professor, Master’s Supervisor, research area: computer networks and distributed systems, data acquisition and processing.
Wang Zhicheng (1982—), Male, PhD student, Associate Professor, research area: new energy technology and applications.
Zhu Qing (1968—), Female, PhD, Associate Professor, Doctoral Supervisor, research area: modern network and communication technology, as well as voice and image information processing technology.
Zhou Xianen (1987—), Male, PhD, Associate Researcher, Senior Engineer, research area: machine vision and high-end equipment.
Peng Guangrong (1968—), Male, Bachelor’s degree, Senior Engineer, research area: planning and manufacturing of coating and surface treatment.
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20240406
Intelligent Charging Monitoring System Based on LoRa and IoT Cloud Platform for Smart Cities
Chu Yang1, Li Dandan1, 2※
（1. Northeast Forestry University, School of Computer and Control Engineering, Harbin 150040; 2. Northeast Forestry University, School of Electromechanical Engineering, Harbin 150040）
Abstract:
In the intelligent charging monitoring process, it is required that sensors can accurately collect data, and the data transmission devices are not affected by external interference during the data transmission process. Based on this, a LoRa intelligent charging monitoring system for charging equipment in smart cities is proposed. The terminal device and gateway of the charging pile are developed using domestically produced APM32 central control chips, and the communication and data transmission module between the device and the gateway uses LoRa modules. The gateway communicates with multiple LoRa device nodes through the LoRa protocol in a one-to-many manner using an “N-ary tree” model; the BL0939 power measurement module is used to collect working voltage, current, power energy, etc., in real-time during the charging process. Each device and gateway is equipped with an AT24C02 EEPROM data storage module, which can protect data in the event of sudden power outages during power line operation; the 4G module WH-GM5 is selected as the wireless communication module for the gateway to communicate with the server. The LoRa protocol can effectively reduce co-frequency interference, thereby improving the reliability and availability of the network. Experimental verification shows that this system can meet monitoring needs in smart cities, resource exploration, and other environments.
Keywords:
Intelligent charging; Sensor; LoRa protocol; Co-frequency interference; N-ary tree
Funding Project:
National Key Research and Development Program Project
（ZKJB230100003）
Author Information:
Chu Yang (1997—), Male, Master’s student, research area: detection technology and automation devices.
Li Dandan (1981—), Female, Master’s degree, Associate Professor, Master’s Supervisor, research area: automatic control, pattern recognition, etc.
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20240407
Prediction of Lower Limb Joint Angles Based on AdaBoost-WOA-HKELM
Li Huaning, Wu Shengbiao※, Feng Li, Liu Jin, Xiong Shuhui
（Donghua University, School of Mechanical and Electronic Engineering, Nanchang 330013）
Abstract:
To address the low prediction accuracy of continuous lower limb movements, a prediction method for hip and knee joint angles based on AdaBoost-WOA-HKELM is proposed. Surface electromyographic signals and joint angle information of the lower limbs during normal walking are collected, and feature extraction is performed on the preprocessed surface electromyographic signals to establish a feature dataset combined with joint angle information. The hybrid kernel extreme learning machine (HKELM) model is selected as the weak learner, and the whale optimization algorithm (WOA) is introduced to optimize the parameters of the HKELM model. The AdaBoost ensemble learning algorithm is used to train the weak learner into a strong learner, establishing the AdaBoost-WOA-HKELM joint angle prediction model. The model is trained and tested using the feature dataset, and simulation comparison experiments for hip and knee joint angle predictions are conducted with HKELM and WOA-HKELM models. The results show that the AdaBoost-WOA-HKELM model performs excellently in predicting hip and knee joint angles, with mean square errors of 2.0869 and 2.2849, respectively, and determination coefficients of 0.9882 and 0.9887. These indicators are significantly better than the other two models, highlighting the outstanding performance of the AdaBoost-WOA-HKELM model in accurately predicting lower limb joint angles. The results close to 1 for the determination coefficient indicate a high degree of fit of the model to the actual data, further validating the effectiveness and accuracy of the AdaBoost-WOA-HKELM model.
Keywords:
Electromyographic signals; Hybrid kernel extreme learning machine; AdaBoost; WOA; Lower limb joint angle prediction
Funding Project:
Jiangxi Provincial Department of Education Fund Project
（GJJ202216）
Author Information:
Li Huaning (1996—), Female, Master’s student, research area: human intention recognition, rehabilitation exoskeleton human-computer interaction.
Wu Shengbiao (1982—), Male, PhD, Lecturer, research area: intelligent control and automation systems, exoskeleton robots, etc.
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20240408
Path Planning Algorithm for Intelligent Connected Vehicles Based on Quadratic Programming
Xiao Yingxue1, He Chao1, 2※, Bao Guangyuan2
（1. Southwest Forestry University, School of Mechanical and Transportation Engineering, Kunming 650224; 2. Yunnan Provincial Key Laboratory of Environmental Protection and Safety for Motor Vehicles, Kunming 650224）
Abstract:
To address the issues of unstable paths, discontinuous curvature, and long computation times in real-time path planning for autonomous vehicles on structured roads, a quadratic path planning algorithm is proposed. A segment of the globally discrete navigation path is extracted for smoothing, and a Frenet coordinate system is constructed; dynamic programming is used in the SL space to make detour decisions around obstacles within the lane, thereby opening up drivable areas. Quadratic programming is utilized to construct a cost function centered on safety and comfort evaluation indicators from the drivable areas, evaluating the cost of the planned path and selecting the optimal path that minimizes the cost. The algorithm framework is built using MATLAB/Simulink, and simulation results show that the paths planned by this algorithm in static obstacle avoidance environments on structured roads are smoother, have smaller curvature, and shorter running times, making them more stable and reliable compared to traditional Apollo algorithms.
Keywords:
Path planning; Quadratic programming; Intelligent connected vehicles
Funding Project:
Yunnan Provincial Department of Education Scientific Research Fund Project
（2020J0418）
Yunnan Provincial High-Level Talent Project
（YNWR-QNBJ-2018-066, YNQR-CYRC-2019-001）
Author Information:
Xiao Yingxue (1999—), Male, Master’s student, research area: autonomous driving planning and control.
He Chao (1980—), Male, PhD, Professor, Doctoral Supervisor, research area: intelligent connected vehicles, has published 50 papers.
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20240409
Simulation Study of Heat Sink for Semiconductor Cooling Module in Reagent Warehouse
Liu Wei1, 2, Lin Fangye1, Wang Yonghao1, 2, Zou Jihua3, Xie Xiaoheng3, Zou Jun2
（1. Zhejiang University, Ningbo “Five-in-One” Campus Education Development Center, Ningbo, Zhejiang 315100; 2. Zhejiang University, State Key Laboratory of Fluid Power and Mechatronic Systems, Hangzhou 310058; 3. Meikang Biotechnology Co., Ltd., Ningbo, Zhejiang 315100）
Abstract:
The heat dissipation performance of the heat sink for the thermal end of the semiconductor cooling module directly affects its cooling efficiency. Therefore, effective heat dissipation methods are essential for the efficient operation of semiconductor cooling modules. To address this issue, a three-dimensional model was constructed based on actual conditions, and a series of studies on the fin-type heat sink at the thermal end were conducted using COMSOL® Multiphysics® software for simulation calculations. The simulation results were analyzed and discussed, exploring the effects of heat sink wind speed, material, and fin parameters on the heat dissipation performance of the heat sink. The results indicate that as the wind speed increases, the thermal end temperature continuously decreases; due to differences in physical parameters such as heat transfer coefficient, specific heat capacity, and density, there are significant differences in the heat dissipation performance of heat sinks made of different materials under the same structure; changes in fin parameters will alter the convective heat transfer process, thereby affecting the heat dissipation performance of the heat sink. Reasonably reducing the fin height and thickness can improve the economic efficiency of the heat sink without significantly reducing its heat dissipation performance. The research results enhance the heat dissipation performance and economic efficiency of fin-type heat sinks, thereby improving the cooling performance of semiconductor cooling modules and providing references for practical engineering applications.
Keywords:
Semiconductor cooling; Heat sink; Thermal end; Convective heat transfer
Funding Project:
China Postdoctoral Fund Project
（2022M721451）
Zhejiang Provincial Natural Science Fund Project
（LD22E050003）
Author Information:
Liu Wei (1998—), Male, Master’s student, research area: fluid transmission.
Lin Fangye (1992—), Male, PhD, Assistant Researcher, research area: mechatronic equipment, has published more than 10 SCI papers.
Wang Yonghao (1998—), Male, Master’s student, research area: fluid transmission.
Xie Xiaoheng (1986—), Male, Master’s degree, Senior Engineer, research area: medical devices and pharmaceutical chemical equipment.
Zou Jihua (1979—), Male, Master’s degree, research area: medical devices and pharmaceutical chemical equipment.
Zou Jun (1977—), Male, PhD, Professor, Young Changjiang Scholar, research area: intelligent equipment, has published more than 50 SCI papers.
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20240410
CFD Simulation Study of Nozzles in Ore Sorting Machines
Deng Xingxing, Chen Rui※
（Donghua University, School of Mechanical and Electronic Engineering, Nanchang 330013）
Abstract:
To address the issues of poor blowing effects and high air consumption in the blowing separation system of ore sorting machines, a converging jet nozzle was selected as the research object. Numerical simulations were conducted using computational fluid dynamics software to analyze the structural characteristics and geometric parameters of the nozzle. The geometric model of the nozzle was established using ANSYS Space Claim software, and the geometric model was meshed using ICEM software, followed by solving with Fluent software, selecting the Realizable k-ε turbulence model for calculations. Factors affecting the jet flow, such as the shape of the contraction curve, length of the contraction section, and outlet diameter, were analyzed. The results indicate that the shape of the contraction section curve affects the nozzle’s jet flow, and the converging nozzle with a Wislicenus curve can maintain good jet stability under high inlet pressure; a nozzle with a 5 mm outlet diameter and an 8 mm contraction section length can meet sorting requirements while saving energy consumption.
Keywords:
Ore sorting machine; Nozzle; Jet flow; Wislicenus curve; Numerical simulation
Funding Project:
National Natural Science Foundation Project
（U22B2077）
Jiangxi Provincial Key Technology R&D Project
（20224AAC01012）
Author Information:
Deng Xingxing (1997—), Male, Master’s student, research area: intelligent control and automation systems.
Chen Rui (1981—), Male, Postdoctoral, Associate Professor, Master’s Supervisor, research area: nuclear radiation detection and imaging, intelligent instrument system design, etc.
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20240411
Rapid Flame Detection Method for Firefighting Needs
Chen Zeshi, Zhong Xiaoyong, Li Huayao, Yang Zhizhi, Chen Yang
（Jiangxi University of Science and Technology, Ganzhou, Jiangxi 341000）
Abstract:
Flame detection devices in firefighting systems face issues such as low accuracy and poor real-time performance during detection tasks, leading to high false alarm rates and missed opportunities for timely rescue. To address these issues, based on the YOLOv7-tiny algorithm, improvements were made to the ELAN-tiny structure, resulting in the design of the ELAN-TP structure, which significantly reduces redundant calculations in the original structure. To enhance the feature extraction capability of the backbone network, the ConvNeXt structure was introduced at the end of the backbone network. The SimAM attention mechanism was used to improve the neck network structure, increasing the model’s positioning accuracy and fusion capability for features of different sizes. The results show that the improved model achieved a flame detection accuracy (mAP@50) of 57.7%, an increase of 4.8% compared to the original model, with a detection frame rate (FPS) of 97, an increase of 13. The improved model was deployed on the edge computing device Jetson Nano, with FPS fluctuating around 20, meeting real-time requirements and effectively performing flame detection tasks in various scenarios, demonstrating high practical value.
Keywords:
Flame detection; Firefighting equipment; Lightweight; Attention mechanism
Funding Project:
National Natural Science Foundation Project
（51665019）
Jiangxi Provincial Key R&D Project
（20212BBE53033）
Author Information:
Chen Zeshi (1995—), Male, Master’s student, research area: computer vision, embedded systems and applications.
Zhong Xiaoyong (1964—), Male, Master’s degree, Senior Engineer, Master’s Supervisor, research area: embedded systems and applications, computer vision.
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20240412
Detection of Foreign Objects on Power Transmission Lines in Foggy Weather Based on YOLOv5-GM
Zhu Yunyan, Zhu Li※, Xiao Tianlong, He Xinyi, Hu Tao
（Hubei Minzu University, School of Intelligent Science and Engineering, Enshi, Hubei 445000）
Abstract:
In foggy conditions, the ability to analyze and recognize foreign objects on power transmission lines is poor, increasing the risk of false alarms or missing key information. An improved algorithm based on YOLOv5, named YOLOv5-GM, is proposed. The dark channel prior dehazing algorithm is used to process the dataset in foggy conditions, and the dehazed dataset is used as input for the YOLOv5 model. The Neck network of the YOLOv5 algorithm is replaced with a GFPN network architecture, and the CSPStage is introduced in the feature fusion module to replace the original 3×3 convolution operation, enhancing the feature fusion effect. During real-time detection, the additional upsampling step is removed, achieving higher detection accuracy without increasing computational load; the CBAM attention mechanism is added to the CSPStage module in the optimized Neck network to improve the module’s generalization ability. The results show that in the detection of multiple foreign objects on power transmission lines, the YOLOv5-GM model’s accuracy (P) improved by 2.5%, the mean average precision (mAP) improved by 4.3%, and the F1 score significantly increased, validating the effectiveness of the proposed model.
Keywords:
Dark channel prior; YOLOv5; GFPN; CBAM
Funding Project:
National Natural Science Foundation Project
（61962019; 61972017）
Author Information:
Zhu Yunyan (1996—), Female, Master’s degree, research area: detection of foreign objects on power transmission lines in complex environments.
Zhu Li (1984—), Female, Associate Professor, research area: wireless sensor network technology, has published more than 30 papers.
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20240413
Vehicle Detection in Complex Environments Based on Improved Faster RCNN with Transformer
Wang Xinzhe1, He Chao1, 2※
（1. Southwest Forestry University, School of Mechanical and Transportation Engineering, Kunming 650224; 2. Yunnan Provincial Key Laboratory of Environmental Protection and Safety for Motor Vehicles, Kunming 650224）
Abstract:
In monitoring perspectives, target vehicles are small and severely occluded, leading to low detection accuracy. By exploring the mutual reference and connection between convolutional neural networks and Transformer models, and combining conventional improvements such as loss functions, a new Faster RCNN model is proposed. By borrowing ideas from the Transformer model, the original feature extraction network is improved, changing the original block ratio from 3:4:6:3 to 3:3:27:3, and increasing the convolution kernel from 3×3 to 7×7 to enlarge its receptive field, better capturing global features in images. Depthwise convolution is used to reduce the number of parameters and slightly improve performance, and channel shuffle is employed to solve the problem of information exchange between channels. The original intersection over union (IoU) is changed to CIoU, further improving the detection effect of small and occluded targets when combined with the improved feature extraction network. On the UA-DETRAC dataset, the improved model achieved a 20.20% increase in [email protected]:0.95 compared to the original algorithm, with improvements of 15.8%, 23%, and 45.8% for large, medium, and small targets, respectively, compared to other models such as YOLOv7, YOLOv5, and Cascade RCNN, which improved [email protected]:0.95 by 3.3%, 5%, and 6.69%, respectively.
Keywords:
Transformer; CIoU loss function; Improved convolutional neural network; Improved Faster RCNN
Funding Project:
Yunnan Provincial High-Level Talent Project
（YNWR-QNBJ-2018-066; YNQR-CYRC-2019-001）
Author Information:
Wang Xinzhe (1999—), Male, Master’s student, research area: target detection.
He Chao (1980—), Male, PhD, Professor, Doctoral Supervisor, research area: intelligent connected vehicles, has published 50 papers.
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20240414
Momentum Exchange Mechanism of Liquid Breakup in Transverse Airflow
Liu Xiaohong, Wen Zhi, Du Yuhang, Su Fuyong, Zhang Sizong, Lou Guofeng
（Beijing University of Science and Technology, School of Energy and Environmental Engineering, Beijing 100083）
Abstract:
The breakup of liquid jets is a complex nonlinear dynamic problem. To study the momentum exchange mechanism between gas and liquid during the breakup process, numerical simulations were conducted using Fluent software to obtain the variation laws of momentum exchange and momentum exchange efficiency during the impact of different airflow on the liquid. Further verification of the laws was conducted using the VOF to DPM model. The results indicate that within the working range of airflow speeds from 40 to 90 m/s and airflow densities from 1.177 to 7.356 kg/m³, the momentum exchange efficiency varies from 62% to 83%. The momentum exchange amount between gas and liquid increases with the increase of airflow speed, and when the gas density remains constant, the momentum exchange efficiency gradually decreases with the increase of airflow speed, eventually stabilizing; when the airflow properties remain unchanged, increasing the liquid density and viscosity both lead to an increase in the momentum exchange efficiency between gas and liquid. The droplet size distribution was used as a calculation index for the liquid breakup effect, and it was found that when the momentum exchange amounts between gas and liquid are equal, the size distribution of the liquid after breakup is basically consistent, with a maximum error of 15.3%.
Keywords:
Transverse jet; Momentum exchange efficiency; Liquid breakup; Droplet size; Numerical simulation
Funding Project:
Hebei Provincial Key R&D Program
（22373805D）
Special Fund for Basic Scientific Research Business Expenses of Central Universities
（FRF-TP-22-077A1）
Author Information:
Liu Xiaohong (1998—), Male, PhD student, research area: liquid breakup, atomization nozzle design, and slag granulation.
Wen Zhi (1962—), Male, PhD, Professor, Doctoral Supervisor, research area: steel metallurgy, industrial furnaces, automatic control, etc.
Du Yuhang (1997—), Male, PhD student, research area: nano-bubbles and plasma spray combustion, etc.
Su Fuyong (1982—), Male, PhD, Professor, Doctoral Supervisor, research area: modeling and control of industrial thermal processes, comprehensive utilization of waste heat and energy.
Zhang Sizong (1989—), Male, PhD, research area: flue gas circulation sintering technology and vertical cooling technology for sintered ore.
Lou Guofeng (1969—) Male, PhD, Associate Professor, Master’s Supervisor, research area: fluid flow simulation, high-temperature melt granulation, etc.
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20240415
Study on the Influence of Mn and Yb Content on the Microstructure and Properties of Non-Thermal Treatment Aluminum-Magnesium Alloys
Peng Xiaobang, Song Xianchen※, Li Qingqing, Li Shikang
（Donghua University, School of Mechanical and Electronic Engineering, Nanchang 330013）
Abstract:
To enhance the mechanical properties of non-heat-treated aluminum-magnesium alloys, aluminum-magnesium alloys with different Mn and Yb contents were designed. Room temperature tensile tests, hardness tests, friction and wear tests, and OM, SEM microscopic observations were conducted to study the effects of different Mn and Yb contents on the microstructure, mechanical properties, and wear resistance of aluminum-magnesium alloys, obtaining the optimal Mn and Yb content for aluminum-magnesium alloys. The results indicate that the addition of Mn weakens the dendritic segregation caused by magnesium, forming a dispersed distribution of fine compounds Al6Mn in the aluminum matrix, which promotes grain nucleation, thereby inhibiting grain growth and refining the grains, improving the alloy’s microstructure. The rare earth element Yb improves the distribution of the second phase and forms fine Al3Yb as heterogeneous nucleation cores, increasing the nucleation rate, resulting in an increased number of grains and smaller grain sizes in the cast structure, thus improving the microstructure of aluminum-magnesium alloys. When the contents of Mn and Yb are both 0.6%, the alloy exhibits optimal mechanical and wear resistance properties. The hardness of the alloy is 73.75 HBS, tensile strength is 278 MPa, yield strength is 214 MPa, elongation is 10.53%, and wear rate is 5.88%. Compared to alloys without Yb, the Brinell hardness, tensile strength, and yield strength increased by 20.31%, 10.31%, and 19.55%, respectively, while the wear rate decreased by 2.08%.
Keywords:
Al-Mg alloy; Microstructure; Mechanical properties; Alloying
Funding Project:
Jiangxi Provincial Department of Education Science and Technology Plan Project
（GJJ170453）
Author Information:
Peng Xiaobang (1999—), Male, from Jingzhou, Hubei, Master’s student, research area: rare earth aluminum alloys.
Song Xianchen (1976—), Male, from Changchun, Jilin, PhD, Associate Professor, research area: rare earth aluminum alloy die casting.
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20240420
Trajectory Transition of 2D Galvo Scanning System Based on Bezier Curves
Zhu Yutian, Liang Zhaoqian※, Zhou Aiguo, Wei Haozhi
（Tongji University, School of Mechanical and Energy Engineering, Shanghai 201804）
Abstract:
The 2D galvo scanning projection system is an emerging research field that projects CAD graphics onto target surfaces to assist in production and manufacturing, effectively improving production efficiency and manufacturing precision. Previously, jump delays were set to ensure the accuracy of scanned graphics during jumps, without considering the motor’s operating conditions. To solve the problem of motor vibration impacts during scanning, trajectory transitions were added to the free segments of the scanning trajectory based on Bezier curves. By combining the equidistant working characteristics of the 2D galvo system for scanning graphics, the conditions for smooth transition of control points of Bezier curves at the junctions of scanning trajectories were derived. Subsequently, trajectory transitions were added to the scanned graphics according to the smooth transition conditions, and optimal selections were made based on the maximum curvature of the trajectory. Finally, the optimization effect of trajectory transitions was simulated and verified based on a typical voice coil motor model. The results indicate that for the 2D galvo scanning laser projection system, using Bezier curves for trajectory transitions is simple and efficient, effectively eliminating sudden changes in speed and acceleration during motor operation, reducing vibration impacts during operation while ensuring the accuracy of scanned graphics.
Keywords:
2D galvo; Laser projection; Trajectory transition
Author Information:
Zhu Yutian (1967—), Male, PhD, Professor, Master’s Supervisor, research area: mechatronic control, engineering machinery drive, mechatronic integration, mechanical control, and information processing technology.
Liang Zhaoqian (1998—), Male, Master’s student, research area: key technologies for laser scanning projection equipment.
Zhou Aiguo (1973—), Male, PhD, Associate Professor, research area: electronic drive, measurement technology applications in machinery, robot system design, and mechanism design and its dynamic modeling.
Wei Haozhi (2000—), Male, Master’s student, research area: calibration of three-dimensional laser projection systems.
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20240421
Preparation and Mechanism Study of La2Ce2O7/YSZ Composite Thermal Barrier Coatings
Kang Yongxia, Chen Shuai, Qi Xiaohan, Tang Jinbo, Tian Yujing, Zhang Xuan
（Xi’an University of Engineering, School of Materials Engineering, Xi’an 710048）
Abstract:
To address the low thermal cycling life of the widely used yttria-stabilized zirconia (YSZ) thermal barrier coatings under CMAS corrosion conditions, La2Ce2O7 (LC)/YSZ composite thermal barrier coatings were deposited using supersonic plasma spraying technology. By cleverly implementing a dual powder feeding mode, the composite of LC and YSZ was achieved, effectively solving the sharp drop in the thermal expansion coefficient of LC material at low temperatures while improving the thermal insulation performance and CMAS corrosion resistance of the composite coating. High-temperature static corrosion experiments and thermal cycling experiments were conducted to study the CMAS corrosion resistance of the LC/YSZ composite coating and its thermal cycling failure behavior under CMAS corrosion conditions. The results indicate that the thermal cycling life of the LC/YSZ composite coating is nearly 90% higher than that of traditional YSZ coatings, attributed to the following three aspects: (1) Mixing LC with YSZ effectively avoids the sharp drop in the thermal expansion coefficient of LC material at low temperatures; (2) The thermal insulation performance of the LC/YSZ composite coating is superior to that of YSZ coatings; (3) The LC/YSZ composite coating can react with CMAS to form a reaction layer composed of La-Ce apatite phase, CaAl2Si2O8, m-ZrO2, and t-ZrO2, effectively preventing CMAS melt from penetrating into the coating.
Keywords:
Thermal barrier coatings; CMAS corrosion; Thermal cycling failure
Funding Project:
Shanxi Provincial Natural Science Basic Research Program Fund Project
（2022JQ-319）
Shanxi Provincial College Student Innovation and Entrepreneurship Training Program Project
（S202210709090）
Author Information:
Kang Yongxia (1990—), Female, from Shanxi, PhD, Lecturer, research area: high-temperature corrosion failure mechanisms of thermal barrier coatings.
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20240422
In-Depth Discussion of Several Theories for Predicting Ship Resistance
Zhang Dapeng1, Zhao Bowen1, Sun Yifang1, Yan Jin2, Luo Yangyang1
（1. Guangdong Ocean University, School of Shipping and Marine Transportation, Zhanjiang, Guangdong 524088; 2. Guangdong Ocean University, Key Laboratory of Intelligent Equipment for Marine Ranching, Zhanjiang, Guangdong 524088）
Abstract:
With the globalization of the world economy, maritime transportation has become an economical and practical mode of transport. The development of maritime transportation relies on various types of ships. When ships navigate in water, they are hindered by the viscous nature of seawater, resulting in ship resistance. To improve the speed of ships in seawater while reducing fuel consumption, it is necessary to calculate ship resistance. Different types of ships have different hull forms, leading to different contact areas with water. Therefore, the calculation methods for ship resistance vary according to the types of ships. The methods for predicting ship resistance can be categorized based on hull types, including algorithms suitable for predicting resistance of planing boats, displacement vessels, yachts, and slender body theory. The discussion results indicate that different algorithms and theories are applicable to different hull types and have specific applicable ranges.
Keywords:
Ship resistance; Planing boats; Displacement vessels; Yachts; Slender body theory
Funding Project:
2021 Zhanjiang Marine Youth Talent Project
（2021E5007）
Author Information:
Zhang Dapeng (1987—), Male, PhD, Lecturer, research area: dynamic response of ships and marine structures, has published 60 papers.
Zhao Bowen (1998—), Male, PhD, research area: dynamic response of ships and marine structures, has published 15 papers.
Sun Yifang (1987—), Male, PhD, research area: dynamic response of ships and marine structures, has published 5 papers.
Yan Jin (1974—), Male, PhD, research area: dynamic response of ships and marine structures, has published 50 papers.
Luo Yangyang (1987—), Male, PhD, research area: dynamic response of ships and marine structures, has published 6 papers.
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20240423
Lightweight Design of Battery Frame for New Energy Commercial Vehicles
Tao Liangming, Ruan Jingkui※
（Hubei University of Automotive Technology, School of Mechanical Engineering, Shiyan, Hubei 442002）
Abstract:
To improve the endurance of new energy commercial vehicles, a lightweight design of the rear battery frame is conducted. The NSGA-II algorithm is used for optimization design, establishing an optimization model and verifying its mechanical performance. The optimal design variables are selected, and the Optimal Space Filling Design (OSF) is used for experimental design to obtain initial sample points. Verification points are selected, and a Kriging model is established for fitting analysis to assess the accuracy of the Kriging model and perform response surface optimization. An optimization model is established using the NSGA-II algorithm to find the optimal solution set, completing the lightweight design of the battery frame. The optimization results indicate that under extreme working conditions while meeting strength requirements, the maximum stress of the battery frame increased by 4.72%, and the mass decreased by 8.6%, achieving the goal of lightweight design.
Keywords:
Battery frame; Optimal space filling design; Kriging model; NSGA-II; Lightweight design
Funding Project:
Hubei Provincial Support for Enterprise Technology Innovation Development Project
（2021BAB018）
Author Information:
Tao Liangming (1999—), Male, from Ji’an, Jiangxi, Master’s student, research area: application of automotive lightweight design.
Ruan Jingkui (1964—), Male, from Shiyan, Hubei, PhD, Professor, research area: automotive structural optimization, mechanical CAD/CAM, and integrated technology.
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Layout Design: Cai ZhuoxiEditor: Wang ZhishengReview: Mai Lijiu
