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    Research Review of Error Compensation Technology for Ultra-precision Machining
    CHEN Qidi, HU Xiaolong, LIN Min, SUN Xiaoxia, ZHANG Tao, ZHOU Zhixiong
    China Mechanical Engineering    2023, 34 (03): 253-268.   DOI: 10.3969/j.issn.1004-132X.2023.03.001
    Abstract1701)      PDF (8557KB)(429)       Save
     Ultra-precision machining technology was a key technology in high-end manufacturing fields. At present, ultra-precision machining has entered the nano scale. Mastering the key technology of ultra-precision machining error control, ensuring and improving the machining accuracy of CNC machine tools, become a hot research point to improve the machining and manufacturing levels. This paper systematically summarized the research status and development trend of ultra-precision machining error compensation technology, and focused on the geometric errors, force induced errors, thermal induced errors and their compensation methods, which had the greatest impact on ultra-precision machining. Then, a series of problems of ultra-precision machining in geometric error separation, cutting force, thermal induced error measurement and compensation were deeply discussed, and it is further pointed out that the ultra-precision machining error compensation technology should also pay attention to the development direction of high efficiency, high precision, generalization, modularization, intelligence and flexibility.
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    Industrial Engineering and Lean Management for Smart Manufacturing
    QI Ershi, HUO Yanfang, LIU Hongwei
    China Mechanical Engineering    2022, 33 (21): 2521-2530.   DOI: 10.3969/j.issn.1004-132X.2022.21.001
    Abstract1429)      PDF (4622KB)(1031)       Save
    This paper reviewed the development routes of developed countries such as the United States, Japan, and Germany since the emergence of industrial engineering for more than 100 years, discussed the regular characteristics of enterprise management innovation, and drew the conclusion that smart manufacturing also needed IE/LM to provide management support. According to the smart manufacturing project cycle, the functions of IE/LM in smart manufacturing engineering were analyzed from the perspectives of basic preparation, scheme selection, and integration development. The framework of lean smart management system for smart manufacturing transformation of Chinese enterprises was given, and the improvement ideas and methods of smart-lean integration were explained based on a case. Finally, some key technologies of smart manufacturing management facing transformation and upgrading of Chinese enterprises were presented based on the actual needs of China. 
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    Development Status and Prospect of Key Rail Grinding Equipment and Technology of Grinding Stone
    ZHANG Wulin, FANXiaoqiang, ZHU Minhao, DUAN Haitao
    China Mechanical Engineering    2022, 33 (19): 2269-2287.   DOI: 10.3969/j.issn.1004-132X.2022.19.001
    Abstract803)      PDF (17216KB)(690)       Save
     The rail grinding strategies and techniques were reviewed, and the key equipment of the grinding methods using grinding wheels(active grinding and high-speed passive grinding)and the milling and grinding compound process were summarized. Meanwhile, the research status of rail grinding stone(grinding wheel, equipped with rail grinding train and used for cutting tools)were reviewed from ingredients, forming processes, structural design and grinding performance evaluation criterions, etc. It was concluded that the fine formula design, scientific evaluation criterions, etc. were the main challenges for the development of high-performance grinding stones. Finally, it was pointed out that the greenization, standardization, and intelligence were the important directions for future development of grinding stone technology. 
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    Review on Management at Mechanical Design and Manufacturing Discipline of NSFC in 2022
    YE Xin, ZHU Mingliang, HUANG Zhiquan,
    China Mechanical Engineering    2023, 34 (04): 379-386.   DOI: 10.3969/j.issn.1004-132X.2023.04.001
    Abstract710)      PDF (2658KB)(317)       Save
    The applications, evaluations and funding of projects at mechanical design and manufacturing discipline (division Ⅱ of engineering science) of the NSFC in 2022, as well as the research progresses and achievements of the executing and finished projects were reviewed. Specific measures of mechanical design and manufacturing discipline were illustrated, such as the reform of scientific fund, talent cultivation and future research. Finally, a short prospect of the work in 2023 was introduced. 
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    Rebound Law and Precision Compensation Method of Three-dimensional Laser Cutting of High Strength Steel Hot Stamping Structural Parts
    LI Shougang, LIU Peng, LIU Xiang, HU Zhili,
    China Mechanical Engineering    2022, 33 (22): 2741-2747.   DOI: 10.3969/j.issn.1004-132X.2022.22.012
    Abstract701)      PDF (7408KB)(103)       Save
    In order to reduce the influences of springback defects on the cutting accuracy in the three-dimensional laser cutting of high-strength steel body structures, the rebound characteristics was studied by applying three-dimensional laser cutting of hot stamped high-strength steel body components.For high-strength steel car body structure A-pillar, hot stamping and laser cutting finite element models were established respectively by the finite element simulation software AUTOFORM and ABAQUS respectively. The rebound value distribution diagram was obtained through numerical simulation, and the rebound law of the contour of the body structures after cutting was found. The optimal cutting contour was determined according to the direct compensation method based on rebound prediction. The compensation method was validated by cutting the A-pillar semi-finished products. The results show that the contour may be controlled within the tolerance range, the contour errors are decreased by about 28.5%, and the profile rebound is decreased by about 38.3%,by the proposed compensation method,which verify the effectiveness of the compensation method.
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    Modeling of Material Removal Depth in ABFW Polishing Based on Modified Preston Equation
    ZHANG Junfeng, SHI Yaoyao, LIN Xiaojun, WU Xiaojun
    China Mechanical Engineering    2022, 33 (22): 2711-2716.   DOI: 10.3969/j.issn.1004-132X.2022.22.008
    Abstract689)      PDF (4289KB)(168)       Save
    Due to the elasticity of ABFW, the actual material removal depth was not consistent with the nominal polishing depth, which directly affected the control of polishing efficiency and surface quality. Based on the Hertz elastic contact theory, the distribution function of polishing pressure and cutting speed in the contact area was established, and the material removal depth model was established according to the modified Preston equation. Based on this, the key processing parameters that affected the material removal depthi.e、abrasive particle size, spindle speed, ABFW deformation and feed rate were determined. Then, the distribution of material removal depth in contact areas and the influences of key polishing process parameters on the material removal depth were obtained. Finally, the correctness of the model and the influence law were verified by simulation and polishing experiments, the results show that the model may better predict the material removal depth of ABFW polishing. 
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    Development of Gear Measurement Technology during Last 20 Years
    SHI Zhaoyao, YU Bo, SONG Huixu, WANG Xiaoyi
    China Mechanical Engineering    2022, 33 (09): 1009-1024.   DOI: 10.3969/j.issn.1004-132X.2022.09.001
    Abstract621)      PDF (72652KB)(545)       Save
    There were two forces that promoted the development of gear measurement technology. One was the continuous new requirements for gear measurement put forward by industrial development, and the other was the penetration of continuously improving related technologies in the field of gear measurement. Since the 21st century, the convergence of these two forces promoted the rapid development of gear measurement technology. Based on a brief review of the evolution of gear accuracy theory and gear measurement technology in the 20th century, the basic framework of gear generalized accuracy theory was put forward. The gear measurement technology during the last 20 years was systematically summarized from the aspects of gear full-information measurement technology, in-site rapid gear sorting and detection technology, extreme measurement technology for extra-large gears and micro gears, high-precision gear artifacts and traceability, etc. There is more than 100 years since the beginning of gear precision measurement, and it is currently in the critical stage of the transition from the 3rd generation to the next-generation of gear measurement. The overall technical concept of next-generation of gear measurement was presented, the basic theory and key technical problems that must be overcome were listed for realizing the next-generation of gear measurement, and the research focus and scientific issues of gear measurement in the next 10 years were prospected.
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    Digital Transformation Mode and Strategy of SMEs in China
    WANG Baicun, ZHU Kailing, XUE Yuan, BAI Jie, ZANG Jiyuan, XIE Haibo, YANG Huayong,
    China Mechanical Engineering    2023, 34 (14): 1756-1763.   DOI: 10.3969/j.issn.1004-132X.2023.14.013
    Abstract614)      PDF (5220KB)(444)       Save
    Promoting the digital transformation of SMEs was of great significance for Chinas manufacturing industries to improve quality and increase efficiency. SMEs were facing problems in digital transformation, such as high cost, fuzzy path, talent shortage, and lacking analytical framework and reference paradigm for digital transformation. The key factors to achieve digital transformation were clarified by building an analytical framework for SMEs digital transformation herein. Through case studies, 4 basic path models of digital transformation of SMEs were summarized and proposed. Based on the above researches, targeted suggestions were proposed for SMEs digital transformation in China, so as to promote the digital and intelligent development of SMEs.
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    Navigation Trajectory Prediction Method of Inland Ships Based on Multi-model Fusion
    ZHANG Yang, GAO Shu, HE Wei, CAI Jing
    China Mechanical Engineering    2022, 33 (10): 1142-1152.   DOI: 10.3969/j.issn.1004-132X.2022.10.002
    Abstract575)      PDF (2807KB)(289)       Save
     Inland waterway navigation was an important part of the modern comprehensive transportation systems. The real-time and high-precision ship trajectory prediction method was helpful to effectively avoid water traffic accidents and enhance the ability of automation and intelligent supervision. Aiming at the problems that the accuracy of the existing inland ship trajectory prediction was not high, in order to improve the short-term prediction accuracy of ship trajectory, comprehensively using the recent AIS (automatic identification system) data and historical AIS data of the ships, and based on the relationship among trajectory and speed, course, and the characteristics of inland waterway, the temporal convolutional network model for speed and course prediction, ship trajectory dynamics equation model and adaptive double-hidden layer RBF network were constructed. The ship trajectory prediction method based on multi-model fusion was proposed. Experimental results show that the proposed method has obvious improvement in trajectory prediction accuracy and may meet the real-time requirements. 
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    A Wafer Cycle Processing Time Prediction Method Incorporating Double Attention Mechanism and Parallel GRU
    DAI Jiabin, ZHANG Jie, WU Lihui
    China Mechanical Engineering    2023, 34 (14): 1640-1646.   DOI: 10.3969/j.issn.1004-132X.2023.14.001
    Abstract574)      PDF (4600KB)(169)       Save
    Low efficiency and low prediction accuracy were caused by the large scale of production feature data, complex correlation among features, and strong correlation of feature samples in wafer fabrication processes, so a wafer processing cycle prediction method integrating double attention mechanism and parallel GRU was proposed. Firstly, Relief-F algorithm was used to reduce the dimensionality of production feature data. Secondly, a fuzzy C-mean algorithm was used to cluster the process similarity of data samples and design a parallel GRU network to explore the strong correlation among wafer feature samples. Finally, a double attention mechanism was designed to learn the complex correlation information within key features and among features and processing cycle. The experimental results show that the proposed method may effectively reduce the prediction training time and improve the prediction accuracy.
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    Hybrid Flow Shop Scheduling Problems with Unrelated Parallel Machine Solved by Improved Adaptive Genetic Algorithm(IAGA) with ITPX
    ZHENG Kun, LIAN Zhiwei, GU Xinyan, ZHU Changjian, XU Hui, FENG Xueqing
    China Mechanical Engineering    2023, 34 (14): 1647-1658,1671.   DOI: 10.3969/j.issn.1004-132X.2023.14.002
    Abstract564)      PDF (4458KB)(128)       Save
    Aiming at the hybrid flow-shop scheduling problems, an adaptive genetic algorithm with ITPX was proposed. Firstly, the solution performance of two-points crossover(TPX) was improved by exacting point taking method. Secondly, adaptive selection probability was demonstrated based on hormonal regulation guiding convergence trend of populations. Then, a pool of high-quality chromosomes and a memory factor were established to record the high-quality chromosomes during population evolution, and two different regional crossovers were implemented. Experimentsal results show that ITPX may save optimization time and improve solution performance; the adaptive probability may enhance convergence; ITPX-IAGA may reduce solution time by more than 40% and improve solution performance.
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    Research on Backlash Elimination Method of Dual-motor Precision Transmission Mechanisms
    ZHENG Jieji, CHEN Lingyu, FAN Dapeng, XIE Xin
    China Mechanical Engineering    2022, 33 (22): 2684-2692.   DOI: 10.3969/j.issn.1004-132X.2022.22.005
    Abstract553)      PDF (6537KB)(318)       Save
    Aiming at the problems of large speed fluctuation and impact caused by the gaps between the two transmission chains of the dual-motor precision transmission mechanisms, the method of eliminating the gaps of the system was studied. First, a mechanism dynamics model including the meshing clearances between the output gear of the planetary reducer and the large ring gear was established. Through the model simulation, the influences of the gap size on the system characteristics were analyzed. Then, a compound anti-backlash method was proposed combining dynamic bias torque based on speed command and cross-coupling synchronous control based on differential negative feedback. An experimental device for dual-motor precision transmission mechanisms was built, and the verification experiments of the anti-backlash method were carried out. The experimental results show that in the case of closed-loop speed, the proposed compound anti-backlash method may ensure the complete elimination of the system gaps, and may improve the system speed tracking accuracy by 73.38%, and the shock amplitude in the start-up phase may be attenuated by 76.35%. The research results lay a certain foundation for the research of the high-precision control method of the double-motor precision transmission mechanisms, and provide a reference scheme for the elimination of the gaps in the gear transmission systems. 
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    Research on Accelerated Life Test Method of Harmonic Reducers
    WANG Qiao, DU Xuesong, SONG Chaosheng, ZHU Caichao, SUN Jianquan, LIAO Delin
    China Mechanical Engineering    2022, 33 (19): 2317-2324.   DOI: 10.3969/j.issn.1004-132X.2022.19.005
    Abstract551)      PDF (5879KB)(286)       Save
    At present, there was an urgent need for an accelerated life test method of harmonic reducer in engineering to replace the full life test in order to reduce the test cycles and costs. Based on the principles of accelerated life test, a constant stress accelerated life test program  was proposed based on the failure characteristics of the harmonic reducer. The flexible wheel that was most likely to fail in the harmonic reducers was taken as the object, and the definite failure judgment, acceleration stress, acceleration factor, method of accelerating model were pointed out. In the small sample test data processing, a more accurate Weibull distribution parameter estimation was obtained by using the maximum likelihood method and Markov Monte Carlo method. The experimental results of the prototype show that the scheme may effectively describe the life of the harmonic reducers. The reliability evaluation standard of the basic rated life is 62% higher than that of the evaluation standard of the median life. The life index of the harmonic reducers was effectively evaluated. The research results have certain engineering application values. 
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    Research Progresses on Surface Integrity of Bearing Grooves
    WANG Dongfeng, YUAN Julong, WANG Yanshuang, CHENG Yongjie, LYU Binghai
    China Mechanical Engineering    2022, 33 (18): 2143-2160.   DOI: 10.3969/j.issn.1004-132X.2022.18.001
    Abstract542)      PDF (5702KB)(442)       Save
    Improving the surface integrity of bearing grooves was an important solution to solve technical problems such as low reliability life, high friction power consumption and unstable vibrations and noises of bearings. On the basis of comprehensive research of generalized surface integrity by domestic and foreign scholars, the definition and connotation of characteristic parameters of bearing groove surface integrity were proposed, and the significance of characteristic parameters and the influence mechanism on bearing performance were expounded. The influences of different processing processes such as forging, turning, heat treatment, grinding and ultra-precision on the surface characteristic parameters of bearing raceways were analyzed in details, and the corresponding control measures were given. The new technologies, new processes, and new methods for improving surface integrity were briefly introduced. Finally, the summary and prospect of improving the surface integrity of bearing grooves were made to provide some references for improving the contact fatigue lifes of bearings.
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    Hydrodynamic Force Calculation Method of Tracked Equipment Based on Artificial Lateral Line#br#
    WU Jiaxiong, SHEN Yanhua , YANG Shudi, FENG Zhipeng
    China Mechanical Engineering    2022, 33 (10): 1135-1141.   DOI: 10.3969/j.issn.1004-132X.2022.10.001
    Abstract532)      PDF (7590KB)(330)       Save
     Aiming at the challenge that the hydrodynamic forces of underwater equipment could not be measured in real time, a method for calculating the hydrodynamic forces of track equipment was proposed based on ALL. Through the ALL system of the track equipment, the pressure values of different incoming flow speeds and angles were extracted, and the distribution law of pressure values was used to perceive the local flow field information of the track equipment. Through the hydrodynamic force restraint experiments of the track equipment combined with the computational fluid dynamics(CFD)simulation method, the functional relationship between the front surface shapes of the track equipment and the viscous coefficient was established. Based on the flow field perception results of the ALL, the hydrodynamic force empirical model of the track equipment was derived. The verification results show that the pressure distribution characteristics of the ALL may effectively identify the incoming flow velocity and angle. The hydrodynamic force empirical model combined with the results of ALL perception may be used to estimate the hydrodynamic force of underwater track equipment in real time, the water resistance calculation error of underwater track equipment model is within the acceptable range of the engineering application. 
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    A Collision Detection Method of Heavy-duty CNC Machine Tools Based on Digital Twin
    JIANG Xuemei, YUAN Zihang, LOU Ping, ZHANG Xiaomei, YAN Junwei, HU Jiwei,
    China Mechanical Engineering    2022, 33 (22): 2647-2654,2663.   DOI: 10.3969/j.issn.1004-132X.2022.22.001
    Abstract524)      PDF (10716KB)(227)       Save
    At present, the collision detection of CNCMTs usually used the basic simulation function of the CNC system to detect machining G codes, which only considered whether there were collisions between the tool and the ideal workbench, or the tool and fixtures on the tool path during the processes. It was difficult to meet the actual dynamic processing environments, clamping mode and fixture change of open heavy-duty machine tools. So the digital twin was introduced into the collision detection of open heavy-duty CNCMTs, and a perception-evolutionary prediction-feedback collision detection framework was constructed. By constructing digital twin of CNCMTs and dynamically sensing machining elements such as workpieces ,fixtures and cutting tools, the evolution of the digital twin should be driven by perception data, and the potential interference phenomenon would be predicted in the machining processes. Thus, the efficiency of the CNCMTs was improved, and the potential harm was avoided. The method was applied to the collision detection of heavy-duty CNC gantry boring and milling machine ZK5520, and the effectiveness and feasibility of the proposed method were proved.
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    Time-series Correlation Prediction of Quality in Process Production Processes Based on Deep TCN and Transfer Learning
    YIN Yanchao, SHI Chengjuan, ZOU Chaopu, LIU Xiaobao
    China Mechanical Engineering    2023, 34 (14): 1659-1671.   DOI: 10.3969/j.issn.1004-132X.2023.14.003
    Abstract523)      PDF (13154KB)(114)       Save
     To address the problems which were difficult to accurately predict production quality due to the temporal coupling of multiple processing parameters in process production, a fast and efficient production quality prediction method was proposed based on deep TCN networks and migration learning. With a sequence-to-sequence learning structure, a deep TCN and a temporal attention mechanism formed the encoding component for extracting key temporal features from multiple sources, while a residual long short term memory network formed the decoding component for simultaneous extraction of quality temporal information, and migration learning was introduced to address the adaptability of the prediction model to online production quality prediction. The experiments show that the proposed method has significant advantages in prediction accuracy and stability, and has high prediction accuracy and computational efficiency in predicting small sample data.
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    Research and Applications of Condition Monitoring and Predictive Maintenance of Marine Diesel Engines
    CHEN Dongmei, ZHAO Siheng, WEI Chengyin, CHEN Yajie
    China Mechanical Engineering    2022, 33 (10): 1162-1168.   DOI: 10.3969/j.issn.1004-132X.2022.10.004
    Abstract511)      PDF (3080KB)(472)       Save
    Based on the four dimensions of thermal-pressure parameters, lubricant oil conditions, vibrations and cylinder pressures, data acquisition and feature extraction were carried out, and a method for diesel engine condition monitoring was proposed based on OCSVM anomaly detection algorithm and Fisher discriminant analysis.  The CUSUMMR was used for parameter trend detection and the D-S evidence theory and weight of evidence method were used for multi-source information fusion. the RUL(remaining useful life) of diesel engine lubricating oil was predicted by LSTM. The Paper solves the problems such as low early warning rate, poor adaptability of the model under diesel engine dynamic conditions. 
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    Design and Performance Verification of Marine Intelligent Water-lubricated Stern Bearings with Temperature Sensing
    XUE Enchi, GUO Zhiwei, YUAN Chengqing,
    China Mechanical Engineering    2022, 33 (14): 1639-1645.   DOI: 10.3969/j.issn.1004-132X.2022.14.001
    Abstract508)      PDF (3728KB)(212)       Save
    An innovative design of marine intelligent water-lubricated stern bearings was proposed to assist the tail shaft system for improving operating state monitoring and performance prediction in harsh environments. Based on the micro embedded self-powered monitoring systems and the water-lubricated bearing structures and material designs, some critical performance parameters of water-lubricated bearings in ship sailing were measured and analyzed in real-time, which were used for operating state identification, evaluation, and life prediction. As an example, the internal temperature of bearings was chosen for feasibility verification of the above intelligent water-lubricated tail bearings by CBZ-1 friction and wear tester. The results show that the internal temperature of the bearings may effectively reflect their lubrication and working conditions. Under water lubrication conditions, the initial period heating rate is as 0.1~0.4 ℃/min, the final period heating rate is as 0~0.01 ℃/min, and the temperature during the steady operations is as 29~33 ℃. Under dry friction conditions, the three data are 0.6~1.4 ℃/min, 0.03~0.25 ℃/min and 36~45 ℃, respectively. The huge temperature differences in different lubrication states make it possible to determine the bearing lubrication conditions, which means that temperature monitoring will greatly improve the reliability of water-lubricated bearings.
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    Tooth Surface Generation and Meshing Characteristics Analysis of Low-angle Face Gear Drives
    ZHOU Ruchuan, WU Wenmin, FENG Manman, GUO Hui, LIN Yanhu
    China Mechanical Engineering    2023, 34 (06): 631-640.   DOI: 10.3969/j.issn.1004-132X.2023.06.001
    Abstract508)      PDF (6100KB)(299)       Save
     Gear geometry and meshing properties of the low-angle face gear drives were investigated in order to enhance meshing capabilities of the gear drives with small shaft angle in helicopter transmission systems. The applied coordinate systems for generation of the low-angle face gear drive were established and the equation of the tooth surface of the small cone angel face gear was derived based on gear meshing theory. The tooth surface equation of a double-crowned cylindrical involute pinion was deduced by application of a generating worm.  The generated double-crowned pinion was then introduced into the low-angle face gear drive. The TCA was implemented and the influences of misalignments on the contact were researched. Stress analysis was performed for the purpose of evaluating the performance of the proposed face gear drives. And the stresses of the low-angle face gear drive were compared with the conical involute gear and cylindrical involute gear pair. The results show that the application of double-crowned pinion avoids edge contact, providing lower contact and bending stresses compared with the face-gear drive with a longitudinal modification pinion. Under the same conditions, the contact and bending stresses of the tapered face gear are 27% decrease than that of the conical involute gears. 
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    Tribological Properties and Anti-friction Electrostatic Properties of CF/PEEK Composites
    PANG Xianjuan, YUE Shiwei, HUANG Suling, XIE Jinmeng, WANG Shuai, SONG Chenfei, YUE Yun, LIU Jian, LI Dong
    China Mechanical Engineering    2023, 34 (03): 277-286.   DOI: 10.3969/j.issn.1004-132X.2023.03.003
    Abstract495)      PDF (16300KB)(169)       Save
    CF/PEEK composites were prepared by vacuum hot pressing sintering technology. The thermal properties of the materials were tested by thermal conductivity analyzer and TG tester. Multifunctional friction and wear testing machine, 3D morphology profilometer, scanning electron microscope and friction electrometer were used to analyze the friction and wear properties and anti-friction electrostatic properties of the materials. The results show that with the increase of the forming temperature, the friction coefficient and wear rate of the materials decrease gradually. With the increase of CF contents, the friction coefficient, wear rate and friction electrostatic voltage decrease first and then increase. When the CF content is as 20%, the friction coefficient, wear rate and friction electrostatic voltage reach the lowest values, which are as 0.247, 5.6×10-6 mm/(N·m) and 3.3 V, respectively. Friction and electrostatic data show that the CF/PEEK materials prepared by this method have better friction properties and anti-electrostatic properties than that of commercial composites. The wear mechanism of CF/PEEK composites is mainly adhesive wear, accompanied by slight abrasive wear.
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    Human Factor Engineering for Human-Cyber-Physical System Collaboration in Intelligent Manufacturing
    YANG Xiaonan, FANG Haonan, LI Jianguo, XUE Qing
    China Mechanical Engineering    2023, 34 (14): 1710-1722,1740.   DOI: 10.3969/j.issn.1004-132X.2023.14.008
    Abstract489)      PDF (5740KB)(261)       Save
    The theoretical system of intelligent manufacturing for HCPS confirmed the central position of human in the intelligent manufacturing system. Starting from the demand of human-machine collaboration in the intelligent manufacturing system, the emphases of human factors in HCIM were discussed from three levels such as behavior, intention, and cognition, based on the theory of gulf. Focusing on virtual-real fusion scenarios, multimodal human-machine interaction, cognitive quantification and other methods, the importance of human factor engineering in promoting the integration of human-computer intelligence was expounded. Finally, research direction and development suggestions of human-centered intelligent manufacturing from the implementation of HCPS intelligent manufacturing systems were put forward.
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    Research on Flexible Job-shop Scheduling Problems with Integrated Reinforcement Learning Algorithm
    ZHANG Kai, BI Li, JIAO Xiaogang
    China Mechanical Engineering    2023, 34 (02): 201-207.   DOI: 10.3969/j.issn.1004-132X.2023.02.010
    Abstract488)      PDF (4473KB)(380)       Save
    The flexible job-shop scheduling problems were transformed into a Markov decision process, and an algorithm D5QN integrated with 5 kinds of deep Q-network (DQN) optimizations was proposed. In the constructing of Markov process, a set of features was extracted to describe the states, and 3 sets of actions were designed by composite rules. The rewards were mapped by direct and indirect methods. The proposed algorithm was compared with the algorithms based on rules, meta-heuristic, and other reinforcement learning, which verifies the proposed algorithm may further decrease the calculating time, and have feasibility and effectiveness. 
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    Research Progresses of Modeling and Optimization Methods for Multi Domain Behavior Processes of Human-Machine Environmental Systems#br#
    DONG Yuanfa, ZHANG Wenli, XIAO Renbin, TIAN Qihua, DU Xuan,
    China Mechanical Engineering    2022, 33 (08): 929-942.   DOI: 10.3969/j.issn.1004-132X.2022.08.007
    Abstract486)      PDF (1784KB)(335)       Save
     Due to the immaturity of intelligent technology in universality, robustness and security, intelligent interactive products were prone to “behavior conflict” due to the mismatch with user behavior patterns in intention expression, information processing, decision logic, interaction timing and action intensity. Unified modeling and optimization of multi domain behavior processes of human-machine environmental systems were the key to realize behavior characteristic regulation and forward design of intelligent interactive products. This paper systematically reviewed the research progresses of multi domain behavior process representation model, modeling language and tool, model validation and behavior process optimization of human-machine environmental systems from four dimensions:how to represent, what to represent, how to verify and how to optimize. The existing problems and limitations in this field were analyzed, and the future research focus and development trend were prospected. 
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    Construction Method of Virtual-real Drive Systems for Robots in Digital Twin Workshops
    LIU Huailan, ZHAO Wenjie, LI Shizhuang, YUE Peng, MA Baorui
    China Mechanical Engineering    2022, 33 (21): 2623-2632.   DOI: 10.3969/j.issn.1004-132X.2022.21.011
    Abstract486)      PDF (2935KB)(360)       Save
     For the current problems for complex modeling and long development cycle of virtual entities such as industrial robots in digital twin workshop construction, a modular construction method of virtual-real drive systems for industrial robots in digital twin workshops was proposed, which divided the virtual-real drive systems into an interaction layer for setting model parameters and a control layer for designing configurations according to functional requirements, and then abstracted the physical industrial robots, etc. into a simulation model from coupling single functional atomic model. The modular and hierarchical approach to building virtual-reality drive systems may quickly and effectively realize the modeling of digital twin virtual entities such as industrial robots, as well as the simulation of industrial robots operating in virtual space and the simultaneous operation of virtual-reality.
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    Design and Performance Evaluation of Amphibious Hexapod Robots
    WANG Yu, ZHOU Shuang, LI Yaxin
    China Mechanical Engineering    2022, 33 (17): 2079-2086.   DOI: 10.3969/j.issn.1004-132X.2022.17.009
    Abstract477)      PDF (7080KB)(212)       Save
    In order to improve the motion performance of the robots in amphibious environment, and to reduce the mechanical complexity and control difficulty of their motion mechanism switching between water and land, an amphibious hexapod robot with compound moving limbs was proposed. Through the land and underwater motion planning of the robots, the stability problem of the robot adapting to different slope terrain was solved. The multi-degree-of-freedom underwater motions of the robots were realized by configuring the positions and poses of the vectored propeller. The simulation results of the robots crawling motion under ADAMS verify that the mechanical design of the robost is reasonable, and also show that the robots have good stability when climbing on different slopes. In order to further evaluate the motion performance of the robots, a prototype robot was built to test the climbing performance of the robots on the slope, and at the same time, the multi-degree-of-freedom motions of the robot under water were verified, including straight, rotating, floating and diving. The experimental results show that the robots have good motion performance both on land and underwater. 
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    Key Geometric Error Analysis and Compensation Method of Five-axis CNC Machine Tools under Workpiece Feature Decomposition
    LU Chengwei, QIAN Bozeng, WANG Huimin, XIANG Sitong
    China Mechanical Engineering    2022, 33 (14): 1646-1653.   DOI: 10.3969/j.issn.1004-132X.2022.14.002
    Abstract477)      PDF (5495KB)(285)       Save
    A method was proposed to analyze and compensate the key geometric errors of five-axis CNC machine tools under workpiece feature decomposition. The complex workpieces were decomposed by the features, and the key geometric errors were identified and compensated through sensitivity analysis under the workpiece feature decomposition, so as to improve the overall machining accuracy of the workpieces. Taking a complex workpiece as an example, firstly, it was decomposed into four typical features: plane, inclined plane, cylinder and cone-frustum. Then, based on the sensitivity analysis, the key geometric errors corresponding to each typical feature were identified respectively. Finally, error compensation was made by feature decomposition. The experiments were carried out on an AC double-turntable five-axis machine tool, and the experimental results show that the sum proportion of key geometric error sensitivity coefficients obtained by identification are all more than 90%. After compensation, the machining accuracy of the four typical features of the workpiece is improved by 20%~30%. The results show that the proposed method may effectively identify the key geometric errors under different workpiece feature decomposition, thus improving the machining accuracy of complex workpieces.
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    Numerical Simulation and Experimental Verification of Pulling-riveting Process of New Non-plate Nuts
    WANG Shoucai, SUN Ang, LIU Rugang
    China Mechanical Engineering    2023, 34 (07): 875-881.   DOI: 10.3969/j.issn.1004-132X.2023.07.014
    Abstract476)      PDF (7273KB)(83)       Save
    Due to the excellent characteristics in improving installation efficiency and reducing fatigue sources, a new type of 304 stainless steel non-plate nut was generalized in aviation field. Based on Johnson-Cook model, the finite element model was built to analyze the pulling-riveting progress. The loading-curve, plastic-flow, clamping force and interference amount, and the influences of interlayer state on riveting quality were analyzed. Meanwhile, the riveting installation tests of nuts were carried out. Results show that the finite element simulation model is in good agreement with the test loading curve, and the maximum load deviation from test is as 2.4%. When the compression stress of the nut is much higher than the yield stress of the material, the instability of the structure occurs, and the bulge structure is formed rapidly. The plastic flow mainly develops along the radial direction. The pulling-riveting process may provide a certain amount of clamping force and interference to interlayer. The clamping force reaches the maximum value after complete riveting, yet in a certain range, the slope of the riveting interlayer does not affect the clamping force. The maximum interference in the riveting processes is about 4.6%.
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    Progresses of Surface Engineering in Extreme Environments and Its Common Scientific Problems
    CHANG Keke, CHEN Leilei, ZHOU Ruonan, XIAO Xuelian, WANG Fangming, WANG Liping
    China Mechanical Engineering    2022, 33 (12): 1388-1417.   DOI: 10.3969/j.issn.1004-132X.2022.12.001
    Abstract475)      PDF (51339KB)(371)       Save
    The strong coupling effects from multi factors in the typical extreme environments of “three depths and one pole” (deep space, deep sea, deep earth and polar) led to the coexistence of multimode damages and failures, such as material corrosion, wear, fatigue, and fracture, which bringed severe challenges to the high precision, high reliability, and ultralong service life of mechanical systems. Surface engineering technology was one of the most effective ways of surface strengthening and life extension. The researches of relevant methods and basic scientific problems were important supports for structural optimization and material designs of highsafety and highreliability mechanical engineering equipment in extreme environments. The general methods of surface engineering technology and their applications in the fields related to extreme environments were introduced, the common basic scientific problems of surface engineering in extreme environments were analysed, focused on the implements of theoretical calculation methods in solving problems, and the development directions of surface engineering in extreme environments were commented.
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    A New Method for Optimal Distribution of Kinematic Accuracy of Mechanical Transmission Systems
    LI Jian, RAN Yan, ZHANG Genbao, WANG Yongqin
    China Mechanical Engineering    2022, 33 (09): 1034-1043.   DOI: 10.3969/j.issn.1004-132X.2022.09.003
    Abstract468)      PDF (2446KB)(297)       Save
    In order to distribute the kinematic accuracy of mechanical transmission system reasonably, a new method for optimal distribution of kinematic accuracy of mechanical transmission system was proposed with the meta-action theory. Firstly, the “function-kinematic-action” structural decomposition tree was used to decompose the mechanical system, and then the basic meta-action and meta-action chain were obtained. Secondly, taking the meta-action chain as research object, the formation mechanism of kinematic accuracy was analyzed, and the kinematic error transfer model was established. Considering cost factors and sensitivity factor of kinematic errors, cost function and robustness function were established. Then the optimal distribution model of the kinematic accuracy of the meta-action chain was established, and the kinematic errors of the meta-action were obtained. An engineering example proved the effectiveness of the method.
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    Applications of Microfluidic Technology in Cross-domain of Mechanical Engineering and Life Science
    MAN Jia, HUA Zesheng, XIA He, LI Jianyong, LI Fangyi, LI Jianfeng,
    China Mechanical Engineering    2022, 33 (15): 1857-1868.   DOI: 10.3969/j.issn.1004-132X.2022.15.012
    Abstract466)      PDF (9998KB)(75)       Save
    Taking microfluidic technology as the research object, the preparation materials and technology of microfluidic chips were introduced, and the applications of microfluidic chip technology in the cross fields of life science were emphasized. It was mainly introduced from three aspects:biological detection, bionic fabrication of in vitro structure and preparation of controllable drug carriers, and the key technologies involved were discussed from the aspects of chip structure design and preparation, functional module integration, process regulation and so on. The application prospect of microfluidic technology in the fields of cross-domain between mechanical engineering and life science was prospected. 
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    Fault Diagnosis Method of Rolling Bearings Based on Simulation Data Drive and Domain Adaptation
    DONG Shaojiang, ZHU Peng, ZHU Sunke, LIU Lanhui, XING Bin, HU Xiaolin
    China Mechanical Engineering    2023, 34 (06): 694-702.   DOI: 10.3969/j.issn.1004-132X.2023.06.008
    Abstract464)      PDF (6394KB)(288)       Save
    To solve the problem that it was difficult to obtain a large number of high-quality rolling bearing fault data in the actual industrial environment, and the generalization performance of the intelligent diagnosis model was poor, a fault diagnosis method was proposed based on simulation data driven and domain adaptation. Firstly, a physical model was established to obtain rich simulation data, which simulated different failure forms of bearings according to bearing parameters and corresponding operating conditions. Secondly, the transfer learning method was used to solve the problem of inconsistent data feature distributions between simulation and actual fault data. The residual channel attention mechanism network was used to extract the transfer fault features of different domains, and the adaptive operation of different domains in the network training processes was carried out through the condition maximum mean discrepancy metric criterion, which taken into account the conditional distribution discrepancies between different domains. Finally, different transfer model tests were carried out on the bearing data sets damaged by man-made damage and accelerated life test. The results show that the method proposed may obtain better recognition accuracy when the target domain contains a small number of labels. 
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    Robot Welding Trajectory Planning and High Frequency Control for Curved Seams
    WU Chaoqun, ZHAO Song, LEI Ting
    China Mechanical Engineering    2023, 34 (14): 1723-1728.   DOI: 10.3969/j.issn.1004-132X.2023.14.009
    Abstract464)      PDF (6070KB)(231)       Save
    In a robotic real-time seam tracking system, the trajectory planning and control delay affected the tracking accuracy and welding quality. To solve this problem, a piecewise real-time trajectory planning and control method for curved seams was proposed by combining B-spline curve interpolation algorithm and EGM module. Firstly, the trajectory was segmented according to the principle of optimal interpolation time. Secondly, three times non-uniform B-spline was used to interpolate each trajectory to obtain the interpolation points. Finally, the high-frequency controller of the robot was designed. The interpolation points were sent to the robot by EGM module in a cycle of 4 ms to guide the robot movements. The experimental results show that this method may complete the planning of sine curve weld and guide the robot welding in 100 ms, and the tracking errors were controlled within ±0.2 mm, which realizes the rapid trajectory planning and high-frequency control.
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    Drag Torque Algorithm of Wet DCT and Its ApplicationsLIU Bo
    ZHANG Xingui, SHI Xinglei, YU Zilin, ZHONG Zhenyuan, LI Jia
    China Mechanical Engineering    2022, 33 (15): 1882-1889.   DOI: 10.3969/j.issn.1004-132X.2022.15.015
    Abstract456)      PDF (5896KB)(158)       Save
    One type of wet DCT was taken as research subject, and the mechanism of output torque variations of the DCT for cars was analyzed in neutral/park positions while creeping or idling respectively. By building the mathematical model of the output torque, theoretical calculation formulas of the equivalent radius of lubricating oil film between DCT plates, the max drag torque and the critical rotational speed were figured out, and the dynamic interactions of three elements were illuminated. The accuracy was proved by experimental data, which may be used to reduce output torque fluctuation, drag torques and critical rotational speeds. 
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    Effects of Laser Cladding Process Parameters on Microstructure and Residual Stresses of Fe-based Double Layer Coatings
    ZHOU Jiali, CHENG Yanhai, CHEN Yongxiong, LIANG Xiubing, BAI Chengjie, DU Wang
    China Mechanical Engineering    2022, 33 (12): 1418-1426,1434.   DOI: 10.3969/j.issn.1004-132X.2022.12.002
    Abstract455)      PDF (13411KB)(306)       Save
     Aiming at the problems that the components had high crack sensitivity due to the intense temperature field changes accompanied by stress and strain evolution in laser cladding processes. The evolution of residual stresses under different laser scanning paths and processing parameters was studied. Fe-based multilayer coatings were prepared by laser cladding on Q345 steels. The residual stress distribution along the coating depth was measured by X-ray diffraction method combined with electrochemical corrosion stripping method. The effects of laser scanning path, power and scanning speed on the microstructure and stress distribution of the coatings were investigated. The results show that the residual compressive stress occurs on the surface and inside of the coatings, the residual stresses changes at the coating-substrate fusion line, and the heat-affected zones are of the residual tensile stress. Laser cladding processes have significant influences on the size and distribution of residual stresses for coatings. When laser scanning path is contour bias, power is as 1.8 kW and scanning speed is as 0.02 m/s, the coatings have the best residual stress distribution and forming quality. The residual stress is mainly related to the impacts of laser beams on the molten pool and the non-equilibrium solidification characteristics of the cladding layers.
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    Study on Mechanics Properties and Numerical Convergence of Gyroid Cellular Structures
    JIANG Chuangyu, ZHANG Baoqiang, CHEN Yun, WANG Cunfu, LUO Huageng, HU Jiexiang, CAO Longchao
    China Mechanical Engineering    2022, 33 (23): 2790-28000.   DOI: 10.3969/j.issn.1004-132X.2022.23.003
    Abstract452)      PDF (14171KB)(106)       Save
    In order to reveal the corresponding relationship between TPMS structure design and mechanics property parameters, the mechanics properties of Gyroid cellular structure(GCS) with different arrangements and the numerical convergence of meshes with different parameters were studied. GCS specimens with fixed volume fraction and unit size were designed. Based on the voxelization model with changing mesh parameters, the convergence analyses of GCS were conducted by finite element method. The correctness of the simulation was verified by tensile test of specimen. Finally, the mechanics properties of the GCS in different arrangements were studied in tensile and bending conditions. Results show that the relative errors of tensile strength and load limit between simulation and experiment are all less than 1.5%. Based on the voxelization method, the number of elements during convergence  may be significantly reduced by adjusting the Jacobian parameters. Quantitative analyses of mechanics properties of variable thickness GCS were conducted. In tensile tests, for 4×4×4 structures, the maximum variation of equivalent elastic modulus along the thickness direction may reach 14.41%. In bending tests, for 20×4×4 structures, the maximum difference of equivalent elastic modulus is as 21.25%. 
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    Low-carbon Scheduling of Multi-objective Flexible Job-shop Based on Improved NSGA-Ⅱ
    JIANG Yixiao , JI Weixi, HE Xin, SU Xuan
    China Mechanical Engineering    2022, 33 (21): 2564-2577.   DOI: 10.3969/j.issn.1004-132X.2022.21.006
    Abstract448)      PDF (6637KB)(260)       Save
     To solve the low-carbon scheduling problems of multi-objective flexible job-shops taking equipment energy consumption, tool wear and cutting fluid consumption as carbon emission sources and energy consumption and labor cost as processing cost, a low-carbon scheduling model was formulated to minimize carbon emission, makespan and processing cost, and an improved elitist NSGA-Ⅱ was proposed to solve the problem. Firstly, the chromosome composition was dynamically adjusted by encoding based on Tent chaotic map and greedy decoding based on analytic hierarchy process to improve the quality of the initial population. Then, an adaptive genetic strategy was proposed based on genetic parameters, which adjusted the crossover and mutation rates according to the population evolution stage and the population non dominated state dynamically. Finally, based on external archives an improved elite retention strategy was designed to improve the population diversity in the later stages of the algorithm and retain high-quality individuals in the evolution processes. The effectiveness of the improved algorithm was verified by standard scheduling examples and a practical case. 
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    Low Frequency Vibration Mechanism for AMB High-speed Motor Rotor Systems and Its Compensation Strategy
    JI Li, MA Xueqing, CHEN Zhenmin
    China Mechanical Engineering    2022, 33 (17): 2053-2060.   DOI: 10.3969/j.issn.1004-132X.2022.17.006
    Abstract448)      PDF (7012KB)(90)       Save
    In industrial applications, a nonsynchronous low frequency vibration occured frequently for high-speed motor systems with AMB. The low frequency vibration was analyzed from two aspects of mathematical model and external excitations. The results show that the low frequency vibration is determined by the natural frequency of the AMB control system, and it is excited by the external noise. Then the compensation strategy was present based on the ESO, and the stability of the AMBs control system was studied. For verification, the simulations and experiments regarding to low frequency vibration were carried out. The results show that under the same white noise excitation, the vibration amplitude of rotor with compensator decreases about 21% compared with that with PID controller. During the speed of 30 000 r/min, the compensator is more effective, and the vibration amplitude of the rotor is reduced by 26.6%. 
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    Metal Defect Image Recognition Method Based on Shallow CNN Fusion Transformer
    TANG Donglin, YANG Zhou, CHENG Heng, LIU Mingxuan, ZHOU Li, DING Chao
    China Mechanical Engineering    2022, 33 (19): 2298-2305,2316.   DOI: 10.3969/j.issn.1004-132X.2022.19.003
    Abstract447)      PDF (8847KB)(208)       Save
    Aiming at the problems of large amount of parameters and calculation in the field of metal defect recognition, a metal defect recognition method was proposed based on shallow CNN and Transformer model. The shallow CNN was used to learn the local information and position information of the images, and the Transformer was used to learn the global information of the images. At the same time, the channel attention module SE was introduced to pay attention to the important feature channels to realize the defect image recognition. The effectiveness of this method was verified by introducing the open defect data set, and the universality of this method was verified by using the self-built defect ultrasonic data set. The experimental results show that the proposed method has strong universality and may effectively identify metal defect images on small and medium-sized data sets. 
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    Research Status and Development of Hybrid Additive Manufacturing Technology
    XIONG Xiaochen , QIN Xunpeng , HUA Lin , HU Zeqi , JI Feilong ,
    China Mechanical Engineering    2022, 33 (17): 2087-2097.   DOI: 10.3969/j.issn.1004-132X.2022.17.010
    Abstract444)      PDF (13696KB)(198)       Save
    The poor forming accuracy and performance restricted the development and applications of metallic additive manufacturing technology. Hybrid additive manufacturing had a significant effectiveness on solving the problem. The classification and main categories of hybrid additive manufacturing technology were highly generalized herein. The research progresses and technical developments of additive and subtractive hybrid manufacturing in the control of the part forming accuracy and surface quality were briefly summarized. The technology categories, forming principles, manufacturing characteristics and key problems of additive and equivalent hybrid manufacturing were emphatically commented, as well as the research status and main conclusions of additive and equivalent hybrid manufacturing on the control of microstructure, stress state and macro-performance of the parts. The acting mechanism of three special auxiliary energy fields, namely ultrasonic, electromagnetic and laser, on the flow, crystallization and solid-state phase transition of additive molten pool, and the evolution law of microstructure state, mechanical properties and forming accuracy of additive layer under the action of special energy fields were systematically introduced. Finally, the development trends of hybrid additive manufacturing technology were prospected in the future. 
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