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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 Abstract （2063）      PDF（pc） （4622KB）（1486）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （2338）      PDF（pc） （8557KB）（1354）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Study on Modeling of Material Removal Depth for Blisk Polishing by ABFW Based on Hertz Contact Theory ZHANG Junfeng, WU Xiaojun, SHI Yaoyao, LIN Xiaojun China Mechanical Engineering    2023, 34 (06): 668-676.   DOI: 10.3969/j.issn.1004-132X.2023.06.005 Abstract （552）      PDF（pc） （5074KB）（1136）       Knowledge map    Save To investigate the material removal mechanism in complex curved surface polishing with ABFW， it was assumed that the distribution of abrasive grain protrusion heights was normal distribution. The distribution model of polishing pressure between ABFW and blade was obtained based on Hertz contact theory. The force analysis of a single abrasive grain was carried out based on the elastic-plastic contact theory， and then the cutting depth model of the abrasive grain was established combined the height distribution function. Thus， the material removal volume of single abrasive grain was determined by synthesizing the spindle speed， feed speed and the shape of abrasive grain cutting groove， and the material removal depth model was established by integrating along the polishing trajectory. The experimental results show that the maximum deviation and average deviation between the predicted values and the experimental ones of material removal depth are 4.85% and 2.95%， respectively， which verifies the correctness and effectiveness of the established model.  Reference | Related Articles | Metrics | Comments（0）

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Multi-objective Robust Optimization Design Method Based on Adaptive Incremental Kriging Model TIAN Zongrui, ZHI Pengpeng, YUN Guoli, GUO Xinkai, GUAN Yi China Mechanical Engineering    2023, 34 (08): 931-940.   DOI: 10.3969/j.issn.1004-132X.2023.08.007 Abstract （514）      PDF（pc） （9011KB）（981）       Knowledge map    Save A multi-objective robust optimization design method of adaptive incremental Kriging model was proposed. Firstly, according to the structural characteristics and optimization objectives, the incremental Kriging surrogate model was constructed, and a hybrid sampling strategy was proposed to improve the adaptability of the incremental Kriging surrogate model. Secondly, the Cauchy mutation MOPSO(CMMOPSO) algorithm was proposed. By improving the inertia weight factor, individual learning factor and social learning factor, and introducing the Cauchy mutation strategy, the efficiency and precision of the optimization model were improved. Finally, an optimization model was constructed with the structural parameters as the design variables, the standard deviation of the performance indicators as the objective, and the 3σ variable reduction interval as the constraint. The optimal solutions of multi-objective robust optimization were obtained combining CMMOPSO and grey correlation analysis. Analysis results of the example show that the proposed method may obtain a high-precision structural optimization model with fewer performance function calls, and the optimization results have faster convergence rate and better robustness than that of traditional methods. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1066）      PDF（pc） （2658KB）（934）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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Research on Interaction between Pedestrian and Automated Vehicle LYU Wei, GUO Fu , LIU Li, ZHANG Zeyu, WANG Tianbo China Mechanical Engineering    2023, 34 (05): 515-523.   DOI: 10.3969/j.issn.1004-132X.2023.05.002 Abstract （909）      PDF（pc） （3924KB）（915）       Knowledge map    Save From the perspective of the pedestrian-vehicle-environment system, the effects of pedestrian safety facility, AVs yielding behavior, approaching direction and eHMI on pedestrian-AV interaction were investigated. Based on a cave automatic virtual environment(CAVE) simulation platform, the Unity 3D software was utilized to design and develop the AVs driving scenario. Thirty-eight volunteers were recruited for the pedestrian-AV interaction experiments. During the experiments, the participants decision time, decision results and subjective experience were recorded and further statistically analyzed with survival analysis. The results indicate that with the presence of an AV in the traffic, pedestrian safety facility, AVs yielding behavior and eHMI may significantly shorten pedestrians decision time, enhance their interactive experience and improve traffic efficiency. However, the influences of pedestrian safety facility on pedestrians crossing decision and behavior exist from the earlier stage of the crossing gap, compared with AVs yielding behavior. Meanwhile, the efficacy and clarity of a light band-based eHMI are somewhat limited for conveying AVs yielding intention. Reference | Related Articles | Metrics | Comments（0）

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Yaw Rate Calculation and Vehicle Stability Control Considering Tire Nonlinearity MIN Delei, TONG Ruting, WEI Yintao China Mechanical Engineering    2023, 34 (21): 2521-2530.   DOI: 10.3969/j.issn.1004-132X.2023.21.001 Abstract （565）      PDF（pc） （7794KB）（882）       Knowledge map    Save Based on the nonlinear tire model， an accurate yaw rate calculation method was proposed to calculate the accurate yaw rate and applied to vehicle stability control. Tire nonlinearity was characterized by the brush model. The equivalent stability factor was obtained by perturbation analysis， and the accurate analytical solution of the yaw rate was obtained. The analysis of the existence of analytical solutions indicates that tire nonlinearity may impact vehicle stability. Real vehicle tests and control simulations based on vehicle models show that considering tire nonlinearity may effectively improve the calculation accuracy of the steady-state yaw rate as the target parameter， and improve the effect of vehicle stability control.  Reference | Related Articles | Metrics | Comments（0）

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Energy Consumption Prediction Method for Industrial Robots TUO Junbo, PENG Qiuyuan, ZHANG Xianmin, LI Congbo China Mechanical Engineering    2022, 33 (22): 2727-2732,2740.   DOI: 10.3969/j.issn.1004-132X.2022.22.010 Abstract （858）      PDF（pc） （2858KB）（863）       Knowledge map    Save Aiming at the defects of complex models, cumbersome operation and high cost of traditional energy consumption prediction methods for industrial robots, a meta-action-based energy consumption prediction method for industrial robots was proposed from the perspective of motion trajectory and action mode of end-effector. First, the meta-actions and energy consumption characteristics of static operations and dynamic operations of industrial robots were analyzed in the first place, and the energy consumption function of static meta-action and dynamic meta-action like axial motion and rotation et al, were built. Then, the motions of the target processes were disassembled based on the proposed meta-action library and the energy sonsumption calculation model of each meta-motion was built. Finally, energy consumption of industrial robots at target processes was realized by combining the energy consumption functions and calculation models. By applying the proposed method, the energy consumption prediction may be realized by disassembling operation processes as long as the energy consumption function of each meta-action was established by measuring meta-action power in advance, so the method has broad application prospects. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （795）      PDF（pc） （6637KB）（834）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （816）      PDF（pc） （5702KB）（832）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Research Progresses of Superhydrophobic Surface Processing Technology and Abrasion Resistance HUANG Yun, HUANG Jianchao, XIAO Guijian, LIU Shuai, LIN Ouchuan, LIU Zhenyang China Mechanical Engineering    2024, 35 (01): 2-26.   DOI: 10.3969/j.issn.1004-132X.2024.01.001 Abstract （854）      PDF（pc） （50387KB）（825）       Knowledge map    Save The abrasion resistance of currently prepared superhydrophobic surfaces is generally poor, which limite the applications in various fields. Studied results found that micro-nano structure and low surface energy were the key factors to achieve superhydrophobic properties. Firstly, based on the mechanism of superhydrophobic surface, the superhydrophobic surface texture was summarized, aiming to solve the wear-prone challenge of micro-nano structures by optimizing the surface texture. Secondly, the superhydrophobic surface processing technology was summarized, and measures to reduce surface energy were analyzed in terms of cost and efficiency which might provide ideas for expanding the superhydrophobic surface processing system. Then, the means of analyzing the abrasion resistance of superhydrophobic surfaces were concluded in detail and the methods of improving the abrasion resistance of superhydrophobic surfaces were described. Finally, the future development prospects of abrasion resistant superhydrophobic surfaces was prospected, with a view to promote the large-scale applications of superhydrophobic surfaces in engineering. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1209）      PDF（pc） （5220KB）（786）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Design and Mechanics Property Analysis for Different Graded Irregular Porous Structures TANG Yongfeng, LU Ping, LIU Bin, JIANG Kaiyong, YAN Binggong, LIU Jiawei, HAN Wei, China Mechanical Engineering    2022, 33 (23): 2859-2866.   DOI: 10.3969/j.issn.1004-132X.2022.23.010 Abstract （816）      PDF（pc） （9383KB）（780）       Knowledge map    Save  Four different type graded irregular porous structures were designed based on the Voronoi diagram， and the four graded porous structure examples were prepared by the stereolithography molding technology. The longitudinal（load direction parallels to the graded direction）and transverse（load direction perpendiculars to the graded direction）compression tests were carried out on the four graded porous structures to study their deformation characteristics and mechanics properties. The results show that the deformation characteristics of the graded porous structures are similar to that of the uniform porous structure during transverse compression processes， and the deformation characteristics of layer-by-layer collapse are exhibited during longitudinal compression processes. In the case of similar porosity， different graded types may affect the mechanics properties in the longitudinal compression processes but have little effect on the mechanics properties in the transverse compression processes. Decreasing the average porosity of the graded porous structures may improve the mechanics properties of the structures. Finally， combining the iso-stress composite model and the Voigt model， the elastic modulus of the graded porous structures were predicted in the longitudinal and transverse compression processes respectively， and most of the relative errors between the predicted results and the experimental ones are less than 10%.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1293）      PDF（pc） （17216KB）（758）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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A Topology Optimized Design Method for High-performance Structures with Fluid-thermal-mechanics Coupling LI Rongqi, YAN Tao, HE Zhicheng, MI Dong, JIANG Chao, ZHENG Jing China Mechanical Engineering    2024, 35 (03): 487-497.   DOI: 10.3969/j.issn.1004-132X.2024.03.011 Abstract （770）      PDF（pc） （5000KB）（730）       Knowledge map    Save The rapid advancement of topology optimization and additive manufacturing technology provided efficient methods for designing and manufacturing high-performance complex equipment. However, current topology optimization techniques for high-performance structures only considered the design of thermal-mechanics coupling or fluid-thermal coupling, and were mostly limited to simple structures. The design under the combined effects of fluid-thermal-mechanics fields was not considered, which restricted the enhancement of structural performance. This paper tackled the challenge of designing high-performance complex structures under multi-physics fields, encompassing fluid-thermal-mechanics interactions. A topology optimization method was proposed to enhance the ability to withstand temperature of intricate structures. Firstly, the governing equations of flow field, temperature field and structural displacement field were introduced to provide a unified description of the fluid-solid materials within the computational domain. Secondly, the topology optimization model was formulated with fluid-thermal-mechanics coupling. The objective function was set to minimize the average temperature, while flow energy dissipation and structural compliance served as constraint functions. Sensitivity analysis of design variables was carried out by using a combination of the variational method and Lagrangian function. Finally, the established topology optimization model was applied to the structural design of a turbine, resulting in a structure suitable for additive manufacturing with excellent heat dissipation performance and well-balanced flow channel distribution. Reference | Related Articles | Metrics | Comments（0）

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Green Scheduling Optimization Method of Special Vehicle Body-in-White Prototype Shops Considering Equipment Preventive Maintenance LI Xixing, ZHOU Wenlong, TANG Hongtao, WU Rui, China Mechanical Engineering    2023, 34 (15): 1832-1847.   DOI: 10.3969/j.issn.1004-132X.2023.15.008 Abstract （387）      PDF（pc） （9794KB）（712）       Knowledge map    Save A typical multi-objective flexible job-shop green scheduling model was established， and the makespan， total energy consumption of equipment and total smoke emission were taken into consideration. And an improved artificial bee colony algorithm was designed to solve this model. Firstly， according to the characteristics of periodic power attenuation of laser equipment， a preventive maintenance strategy that could distinguish laser equipment from ordinary mechanical equipment was proposed to reduce the makespan and the frequency of equipment failure. Then， a mutation method was designed based on equipment allocation and power selection， which could improve the local search ability of the algorithm. A selection method was introduced based on crowded distance in the follow bee search stage for population regeneration to obtain high-quality individuals. Finally， the comparison experiments were carried out based on the expanded common benchmark. Meanwhile， the effectiveness and feasibility of the model and algorithm were verified through the production case of a special vehicle body-in-white prototype workshop in an automotive equipment manufacturing enterprise.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （847）      PDF（pc） （2935KB）（705）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1019）      PDF（pc） （5879KB）（704）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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Patent Data Driven Product Innovation Design Based on SAO LIN Wenguang, LIU Xiaodong, XIAO Renbin China Mechanical Engineering    2023, 34 (15): 1765-1777.   DOI: 10.3969/j.issn.1004-132X.2023.15.001 Abstract （557）      PDF（pc） （5241KB）（699）       Knowledge map    Save The patent data-driven product innovation design method was proposed based on SAO using big data mining technology. Firstly， semantic dependency parsing was used to mine the SAO structure and interaction relationships among product components from patent text databases. Subsequently， a complex network knowledge model was constructed for product systems， and the constraint coefficients of components in the complex network were calculated by using structural hole theory to identify the innovative target components. Then， the semantic similarity coefficients of components were calculated using Word2Vec， and the functional similarity coefficients were calculated using SAO similarity algorithm. And the recommendation algorithm and combination matrix were integrated to achieve structural innovation， functional innovation， and functional optimization. Finally， a typical bathroom shower product was taken as an example to demonstrate the method in detail， which fully verifies the effectiveness and progressiveness of the method.  Reference | Related Articles | Metrics | Comments（0）

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Study on Influences of Ni Content, Nitriding Hardening Depth, and Shot Peening on Bending Fatigue Performance of 42CrMo Gears WU Zhongrui, CHEN Difa, WU Jizhan, YANG Yudian, LIU Huaiju China Mechanical Engineering    2024, 35 (03): 394-404.   DOI: 10.3969/j.issn.1004-132X.2024.03.002 Abstract （383）      PDF（pc） （9652KB）（694）       Knowledge map    Save  Single tooth bending fatigue tests were conducted on 42CrMo gears with different combinations of Ni content, nitriding hardening depth, and shot peening. The effectiveness of different process combinations on improving the bending fatigue limit of gears was investigated, providing process guidance for gear fatigue resistance manufacturing. Additionally, the contribution of surface hardness, nitriding hardening depth, surface residual stress, and Ni content to the bending fatigue limit of gears with different process combinations was analyzed using the random forest algorithm. A multiple regression model considering surface hardness, nitriding hardening depth, surface residual stress, and Ni content was established to predict the bending fatigue limit of gears. Comparing the predicted values with experimental values, the maximum error is controlled within 7.80%, providing a theoretical basis for the rapid and low-cost assessment of gear bending fatigue limit in engineering applications. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1010）      PDF（pc） （6537KB）（650）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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Design and Steering Angle Control of Steering-by-Wire Hydraulic Systems for Multi-axle Vehicles LIU Jun, SHI Chaohuan, LIN Beiqing, HUANG He China Mechanical Engineering    2022, 33 (14): 1741-1750.   DOI: 10.3969/j.issn.1004-132X.2022.14.013 Abstract （723）      PDF（pc） （6050KB）（639）       Knowledge map    Save The angle of the third axle steering wheel under the cargo box and the front steering wheel under the cab of multi-axle vehicles were required to conform to Ackerman principle for reducing rear steering wheel wear. The steering-by-wire hydraulic system was designed and the dynamics model was established based on a certain 8×2 four-axle heavy truck for controlling the steering angle of the third axle steering wheel. The sliding mode controller based on the exponential approach law was simulated in the typical operating conditions, and vehicle experiments were carried out. The experimental results show that the sliding mode controller based on the exponential approach law has faster response, shorter approaching time and overshoot duration, and smaller steady-state difference, compared with the sliding mode controller based on the proportional switching function and open-loop controller. Installation of the steering-by-wire hydraulic system based on the controller may significantly improve the steering wear resistance of the third axle tire, and improve the steering performance of the vehicles, compared with the mechanical hydraulic steering systems. Reference | Related Articles | Metrics | Comments（0）

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Pivot Steering Control of Off-road Vehicles Driven by In-wheel Motors FU Xiang, LIU Zexuan, , LIU Daoyuan, LI Dongyuan, China Mechanical Engineering    2023, 34 (10): 1251-1259.   DOI: 10.3969/j.issn.1004-132X.2023.10.015 Abstract （581）      PDF（pc） （6293KB）（628）       Knowledge map    Save In order to solve the problems of large minimum turning radius and inadequate steering maneuverability of Ackermann steering-based off-road vehicles， a road adaptive pivot steering control strategy was developed by taking advantages of the independent control of vehicle torque driven by in-wheel motors. A seven-degree-of-freedom pivot steering dynamics model was constructed to explain the evolution of the longitudinal and transverse coupled motion tire forces during pivot steering， and a quantitative model was established to quantify the pivot steering resistance moment and transverse sway moment with wheel slip rate and road adhesion coefficient. The desired trajectory of transverse sway angular velocity under different adhesion conditions was designed with steering power responsiveness as the optimization objective， and the safety threshold of each wheel slip rate was used as the stability constraint to reduce the steering center offset. The executive layer tracked the transverse angular velocity based on the model prediction algorithm， while the adaptive sliding mode controller was introduced to adjust the wheel slip rate to ensure the stability of the longitudinal and transverse motions. Simulation tests and real vehicle tests show that the developed pivot steering control strategy achieves accurate tracking of the desired pivot steering trajectory under high， medium and low adhesion surfaces， and limits the steering center offset to within 500 mm， which improves the pivot steering flexibility and lateral stability of the off-road vehicles and realizes "fast and stable" pivot steering.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （874）      PDF（pc） （4473KB）（610）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （727）      PDF（pc） （5896KB）（606）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （802）      PDF（pc） （6100KB）（599）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （878）      PDF（pc） （6394KB）（594）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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Conceptual Design of Bio-inspired Jumping Mechanisms for Flapping-wing Aerial Vehicles MA Dongfu, SONG Bifeng, XUE Dong, XUAN Jianlin China Mechanical Engineering    2022, 33 (15): 1869-1875，1889.   DOI: 10.3969/j.issn.1004-132X.2022.15.013 Abstract （782）      PDF（pc） （3792KB）（591）       Knowledge map    Save Aiming at the problems of lack of autonomous take-off and landing functions of flapping-wing aerial vehicles， which seriously affected the applicable scenarios， the design of bio-inspired jumping mechanisms was carried out. Firstly， the typical movement state of birds in the processes of jumping taking-off was analyzed. And according to the laws of movement changes of the hind limb skeleton structure， center of gravity， force and velocity in this process， the dynamic movement process of jumping take-off of the flapping-wing aerial vehicles was designed. Then， based on the skeleton anatomical structure of birds leg， a closed-chain five-bar geared bird-leg like jumping mechanism was designed. The kinematics equation of the mechanism was derived based on D-H method， and the dynamic equation of the mechanism in the take-off stage was established using Lagrange equation. Finally， the detailed structure design of the jumping mechanism was carried out， and then the simplified jumping model was simulated and analyzed by ADAMS. The simulation results show that， with the help of the designed bionic jumping mechanism， the velocity of mass center of the flapping-wing aerial vehicle system reaches 8.4 m/s， which is higher than the speed 7.9 m/s required by the “dove” aerial vehicle， so the mechanism has the possibility of jumping take-off. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （804）      PDF（pc） （7080KB）（590）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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A Bionic Bouncing Robot Design and Made Inspired by Locusts WANG Kaidi, CHEN Suifan, TANG Wei, QIN Kecheng, LI Qipeng, YANG Zhan, LIU Yang, ZOU Jun China Mechanical Engineering    2023, 34 (24): 2946-2951.   DOI: 10.3969/j.issn.1004-132X.2023.24.006 Abstract （652）      PDF（pc） （3896KB）（588）       Knowledge map    Save  In order to improve the mobility of small robots and increase the diversity of movement gait, a jumping robot imitating locust bouncing was designed based on the body structure and movement mechanism of locusts, and the main body was made by 3D printing. And for reproducing the locusts bouncing mechanism, a torsion spring was installed at the joints of the robot body to simulate the locusts SLP(semilunar energy storage) mechanism. When the robot met an obstacle, the torsion spring released the stored elastic potential energy and generated a ground reaction force, which realized the robots bouncing and thus crossed the obstacle. The robot might imitate the locusts jumping actions, and simulate the locusts flexibility to a certain extent. It was experimentally verified that the robot has good jumping performance, with a jumping distance of up to 100 cm and a jumping height of up to 120 cm which is about 15 times of the own length. Reference | Related Articles | Metrics | Comments（0）

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Evolution of Concept of Machine Composition from the 19th Century to Modern Time ZHANG Ce, YANG Tingli, LIU Jianqin China Mechanical Engineering    2023, 34 (10): 1135-1139.   DOI: 10.3969/j.issn.1004-132X.2023.10.001 Abstract （688）      PDF（pc） （2405KB）（587）       Knowledge map    Save  With increasing of productivity and development of machines， the concept of “machine composition” also evolved. The requirements of modern society for machines were gradually increasing， and complex machines came from the transformation of traditional machines. Understanding the evolution of machines was a necessary process for the transformation of traditional machines. Marx first described the composition of machines in his Das Kapital， which coincided with the start of the Second Industrial Revolution. However， within only a few years， the control system joined a machine， and Marxs “concept of machine composition” began to be broken through. In the second half of the 20th century， in the Third Scientific and Technological Revolution， the concept of mechatronics emerged， and electronic technology， control technology and sensor technology were integrated into mechanical systems. The evolution processes of the concept of machine composition were explained through the history of the development of machines herein. By analyzing the evolution of the concept of machine composition， a more accurate definition of modern mechanical systems was put forword. It may enlighten people， increase their understanding of the machine itself， which has guiding significance for modern mechanical product designers.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （870）      PDF（pc） （5740KB）（582）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Multi-dimensional Dynamic Bayesian Network and Its Importance Measure Analysis Method CHEN Dongning, HU Yanlong, YAO Chengyu, WANG Kuantong, MA Lei, China Mechanical Engineering    2022, 33 (19): 2340-2346.   DOI: 10.3969/j.issn.1004-132X.2022.19.008 Abstract （723）      PDF（pc） （4440KB）（579）       Knowledge map    Save The Bayesian network analysis method was an important method of reliability analysis, but the traditional Bayesian network analysis method was limited to analyze the influences of single factors, and there was a large analysis deviation when the system reliability was affected by multiple factors. Therefore, a multi-dimensional dynamic Bayesian network analysis method was proposed, which used unit step function and impulse function to construct Bayesian network time continuity, and established the failure probability distribution function when the root node was affected by multiple factors. Then, a multi-dimensional dynamic Bayesian network importance measure analysis method was proposed by expanding the traditional importance measure analysis method. Through the engineering example analyses of the hydraulic system of the bucket wheel machine tensioning mechanisms, and compared with the analysis results of the discrete-time Bayesian network analysis method, the feasibility and superiority of the multi-dimensional dynamic Bayesian network and its importance measure analysis method were verified, which provides a more accurate quantitative basis for system improvement and weak link identification. Reference | Related Articles | Metrics | Comments（0）

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Design and Control Algorithm for Hexapod Landing Gear of Unmanned Helicopter LIU Haolin, LIU Xiaochuan, REN Jia, WANG Jizhen, DONG Jiuxiang, FANG Zheng China Mechanical Engineering    2023, 34 (04): 421-430，439.   DOI: 10.3969/j.issn.1004-132X.2023.04.006 Abstract （630）      PDF（pc） （8838KB）（547）       Knowledge map    Save Unmanned helicopter played an extremely important role in combat, patrol, anti-submarine, rescue and transportation, but the traditional landing gear had higher requirements for take-off and landing environment. Aiming at the problems of adaptive take-off and landing on complex terrains, landing and parking on ship surfaces in harsh sea conditions, and improving survivability of emergency collision, a bionic legs landing gear system of unmanned helicopters was proposed based on multi-link mechanism, and the control algorithm was studied and the modeling and simulation were completed. First from bionic legs quantity, distribution form, DOF configuration and needed to complete the function of the legs, the bionic legs landing gear machinery configuration was analyzed, and the kinematics and dynamics analysis of the hexapod landing gears were completed, and then aiming at the adaptive landing processes of the bionic legs landing gear, buffer landing and terrain modeling algorithm were studied. Finally, a virtual prototype simulation model was built based on the control algorithm to effectively complete the landing simulation and prototype test of various terrains. The results show that the design of the bionic legs landing gear structure and control algorithm may achieve dynamic adaptive landing and smooth buffering during the landing processes. Reference | Related Articles | Metrics | Comments（0）

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Research on Underwater Gliders Path Tracking Based on Reinforcement Learning Algorithm SHI Qingqing, ZHANG Runfeng, ZHANG Lianhong, , LAN Shiquan, China Mechanical Engineering    2023, 34 (09): 1100-1110.   DOI: 10.3969/j.issn.1004-132X.2023.09.011 Abstract （556）      PDF（pc） （6340KB）（546）       Knowledge map    Save Aiming at the large deviations between the actual paths and the predetermined ones of underwater gliders affected by ocean current, a neural network ocean current prediction model with long-term and short-term memory and attention mechanism was established based on the traditional long-term and short-term memory network model.The dynamic Q-table of underwater glider motions was generated by depth neural network, and the optimal motion attitude was selected by reinforcement learning algorithm. Considering the influences of ocean current, an underwater glider path tracking algorithm was constructed based on depth reinforcement learning. The results show that the long-term and short-term memory network based on attention mechanism has less mean square errors and root mean square errors in ocean current prediction than that of the traditional integrated moving average autoregressive model and long-term and short-term memory network.Compared with the traditional PID control, the deep reinforcement learning model may reduce the root mean square errors of the underwater glider trajectory by 50.9%, and significantly improve the path tracking accuracy. Reference | Related Articles | Metrics | Comments（0）

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Topology Optimization Design of Aero-engine External System Brackets for Additive Manufacturing MENG Liang, ZHONG Mingzhe, LI Wenbiao, XIA Liang, GAO Tong, ZHU Jihong, ZHANG Weihong, China Mechanical Engineering    2022, 33 (23): 2822-2832.   DOI: 10.3969/j.issn.1004-132X.2022.23.006 Abstract （742）      PDF（pc） （8396KB）（539）       Knowledge map    Save The mechanics properties of aero-engine external system supports under critical loading conditions were analyzed. The support smoothness under two kinds of ultimate load conditions was used as objective function. The topology optimization design and performance check of external system supports for additive manufacturing were conducted using transverse isotropic model of additive manufacturing materials. The results of the mechanics test of metal laser additive manufacturing samples shows that， compared with the initial structure， the support design for additive manufacturing has a 15% less material usage， the stiffness increases by about 20%， and the first-order natural frequency improves by 15%. The structural strength increases significantly. The integrated additive manufacturing with 1 external system support， 2 piping supports and 4 rivets was realized herein， which effectively improves the quality and efficiency of engine assembly. The ground static load and engine ignition tests were successfully passed.  Reference | Related Articles | Metrics | Comments（0）

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Intention Recognition Method of Human Robot Cooperative Assembly Based on EEG-EMG Signals DONG Yuanfa, JIANG Lei, PENG Wei, ZHOU Bin, FANG Zifan China Mechanical Engineering    2022, 33 (17): 2071-2078.   DOI: 10.3969/j.issn.1004-132X.2022.17.008 Abstract （666）      PDF（pc） （7217KB）（535）       Knowledge map    Save  Aiming at the problems of low accuracy and poor stability of identifying cooperative intention based on single source physiological electrical signals in human robot cooperative assembly scene， firstly， support vector machine was used to recognize single source cooperative assembly intentions from EEG and EMG signals respectively， and then D-S evidence theory was used to fuse the recognition results of multi-source cooperative assembly intentions. A human robot collaborative assembly intention recognition method was proposed based on EEG-EMG signals. Experimental results show that the proposed method may effectively improve the accuracy and stability of human robot cooperative assembly intention recognition.  Reference | Related Articles | Metrics | Comments（0）

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Study on Design of Wheel-leg Deformable Wheel and Vehicle Control GENG Xueqing, WU Mengwu, HUA Lin, China Mechanical Engineering    2023, 34 (12): 1446-1452.   DOI: 10.3969/j.issn.1004-132X.2023.12.007 Abstract （583）      PDF（pc） （6422KB）（533）       Knowledge map    Save  In view of the demands of vehicle mobility and obstacle-crossing ability in complex terrain and road conditions, a deformable wheel structure was designed with the characteristics of switching between wheeled and legged states under different terrain and road conditions. The design principle of the deformable wheel was introduced and the structural parameters were calculated and optimized, the maximum diameter ratio of the wheel-leg deformable wheel was obtained. A set of simple and effective wheel-leg deformation control system was also designed. And then the vehicle layout design and movement process analysis was carried out. Finally, a prototype vehicle platform was made to verify the mobility and obstacle-crossing ability by physical experiments. The results show that the deformable wheel may be quickly and intelligently switched between wheeled and legged types, which enables the vehicle to run stably on both structured and unstructured roads, resulting in a high mobility and obstacle-crossing ability of the vehicle system. Reference | Related Articles | Metrics | Comments（0）

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Strength-constrainted Topology Optimization Based on Additive Manufacturing Anisotropy HE Zhicheng, YANG Dingding, JIANG Chao, WU Yi, JIANG Hexin China Mechanical Engineering    2022, 33 (19): 2372-2380，2393.   DOI: 10.3969/j.issn.1004-132X.2022.19.012 Abstract （757）      PDF（pc） （6452KB）（528）       Knowledge map    Save The particularity of additive manufacturing processes leds to the fact that the manufacturing structure exhibited anisotropic mechanics properties. In order to meet the more stringent structural strength design requirements， atopology optimization strategy considering anisotropic strength constraints was proposed based on bi-directional evolutionary structural optimization. The anisotropic Tsai-Hill failure coefficient evaluating additive structural strength was derived， and an objective function containing the constraint of failure coefficient was established by the scale factor. The sensitivity numbers were analyzed in detail， moreover， numerical methods such as sensitivity normalization were used to stabilize the optimization processes. It shows that the proposed method effectively suppresses the high failure risk area， thus， ensures the structural strength， and may obtain better results than that of von-Mesis stress-dependent design under material anisotropic strength assumption. In addition， the optimization results are deeply rely on the variation of anisotropy and the material stacking angle parameters， therefore reasonable tuning will help to optimize structural properties.  Reference | Related Articles | Metrics | Comments（0）

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Online Diagnostic Inspection and Prediction of Product Quality in Injection Molding Intelligent Factories Based on Data Mining CHEN Yu, XIANG Wei, GONG Chuan China Mechanical Engineering    2023, 34 (14): 1749-1755.   DOI: 10.3969/j.issn.1004-132X.2023.14.012 Abstract （682）      PDF（pc） （1793KB）（517）       Knowledge map    Save The dimensional accuracy of injection products was related to the injection processing parameters, and the real-time conditions of each stage in the injection processes and the changes of real-time working conditions. A workpiece quality diagnosis model was developed herein based on data mining. The real-time data collected by high-frequency sensors such as temperature, pressure, and displacement etc. in mold were used to construct the high-dimensional time series feature set. A three-stage feature selection method was used to determine the key feature subset, which was used to train the online quality detection model based on LightGBM classifier. The future values of each features were predicted based on the CNN-LSTM temporal prediction model, and the product quality was forecasted in advance with the classifier. The results show that the average recall rate of the macros is as 89.1%, and the average recall rate of the macros is as 81.6%. Reference | Related Articles | Metrics | Comments（0）