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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 （1539）      PDF （4622KB）（1099）       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

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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 （864）      PDF （17216KB）（702）       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

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China Mechanical Engineering    2022, 33 (12): 1-.   Abstract （378）      PDF （181211KB）（589）       Knowledge map    Save Related Articles | Metrics

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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 （1764）      PDF （8557KB）（552）       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

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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 （688）      PDF （5220KB）（501）       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

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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 Abstract （566）      PDF （3080KB）（496）       Knowledge map    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.  Reference | Related Articles | Metrics

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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 （341）      PDF （50387KB）（488）       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

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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 （581）      PDF （5702KB）（472）       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

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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 （431）      PDF （2405KB）（429）       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

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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 （540）      PDF （4473KB）（410）       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

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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 （533）      PDF （2935KB）（396）       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

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Scale Optimization of Humanoid Robotic Arms Based on Kinematic Performance Analysis SUN Peng, LI Yanbiao, ZHANG Cong, SHAN Xiaohang, YUE Yi, WEI Baochen China Mechanical Engineering    2022, 33 (19): 2331-2340.   DOI: 10.3969/j.issn.1004-132X.2022.19.007 Abstract （449）      PDF （10626KB）（381）       Knowledge map    Save  Aiming at the problems that the coupling effect of multi-joint series mechanisms on the kinematic performance of the end-effector， the kinematic characteristics of series-parallel hybrid mechanisms were analyzed， and a multi-parameter plane model was proposed to realize visualized design. Based on screw theory， the kinematics transfer matrices of serial and parallel joints were established respectively， and the corresponding performance indexes were set up. According to the multi-parameter plane model， the coupling relationship among parameter scale， orientation workspace， and performance indexes were further revealed through a three-dimensional visualization graphics. Finally， the values of parameters， the range of high-quality orientation workspace， and the distribution of indexes were confirmed. The results show that the global performance indexes of the shoulder and wrist joints are as 0.78 and 0.67， respectively， and the global condition number of the elbow joint is as 2.38. The hybrid configuration has functions similar to that of the human arm joints， and gives full play to the comprehensive advantages of series and parallel mechanisms.  Reference | Related Articles | Metrics

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Association between Wear Resistance of TiVN Coatings and Their Cutting Performance FAN Qingbo, YANG Fan, GUAN Xiaoyan, LI Hao, FAN Xiaoqiang, ZHU Minhao China Mechanical Engineering    2022, 33 (12): 1493-1503.   DOI: 10.3969/j.issn.1004-132X.2022.12.011 Abstract （372）      PDF （27231KB）（379）       Knowledge map    Save TiN and TiVN coatings were prepared by multi-arc ion deposition technology, and the tribological and cutting performance of the coatings at different conditions were compared, then the main factors affecting the service performance of tool coatings were pointed out. The experimental results show that V doping may effectively improve the hardness and bonding forces of TiN coatings, and reduce the friction factor and wear rate of TiN coatings at low temperature. However, the TiVN coatings have a higher wear rate when the temperature is higher than 500 ℃, and this is ascribed to the easy oxidation of V. The cutting tests show that TiN and TiVN coatings flake easily on the main cutting edges and transverse edge areas of the twist drills， whilst, there is no significant peeling of the coatings on flank surfaces of the cutting tools. It is supposed that the excellent cutting performance of TiVN coatings is ascribed to the high bonding strength and wear resistance. The service performance of the tool coatings is related to the wear resistance and bonding strength. In addition, the main cutting edges and chisel edge areas of the tools have strict requirements on the wear resistance and bonding strength. Meanwhile, the temperature of the cutting edge tips is high, which shows a high requirement for  high temperature wear resistances and bonding strength of the coatings. Reference | Related Articles | Metrics

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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 Abstract （505）      PDF （51339KB）（375）       Knowledge map    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. Reference | Related Articles | Metrics

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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 （420）      PDF （2858KB）（375）       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

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Dynamics Modeling Method of Complex Rotors for Aero-turboshaft Engines WANG Longkai, WANG Ailun, YIN Yijun, JIN Miao, HENG Xing China Mechanical Engineering    2022, 33 (13): 1513-1520.   DOI: 10.3969/j.issn.1004-132X.2022.13.001 Abstract （461）      PDF （6544KB）（373）       Knowledge map    Save To establish the dynamics model of complex rotor systems in turboshaft engines，the complex structure was modeled by substructure method on the basis of finite element method and piecewise linear fitting. After reducing the degrees of freedom of the systems，motion equations of the rotor systems were derived. The validity of the model was verified by theoretical analysis and experiments，and the vibration characteristics of the gas generator rotors were analyzed. The results show that the established model may significantly reduce the complexity of the overall systems and greatly shorten the calculation time under the premise of ensuring the solution accuracy. Reference | Related Articles | Metrics

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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 （489）      PDF （3924KB）（353）       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

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Research Progresses of Finishing Technology for Inner Channel of Additive Manufacturing Parts WANG Lei, WU Yuliang, ZHAO Jiyuan, LU Bingheng, China Mechanical Engineering    2023, 34 (07): 757-769.   DOI: 10.3969/j.issn.1004-132X.2023.07.001 Abstract （365）      PDF （17271KB）（345）       Knowledge map    Save In the field of aerospace, metal additive manufacturing technology had broad application prospects in the formation of parts with complex inner channels. However, the finishing of additive manufacturing parts with complex inner channels was a bottleneck problem in industrial applications. The principle, technology and development of mechanical polishing, chemical and electrochemical polishing and electrolyte plasma polishing on inner channel were reviewed herein. In addition, the adaptability and exploration direction of mechanical polishing, chemical and electrochemical polishing and electrolyte plasma polishing for the finishing of inner channel of additive manufacturing parts were studied respectively. Finally, the development trend of the key technologies for the finishing of inner channel of additive manufacturing parts was put forward: ①the finishing technology research of the inner channel of the additive parts for functionally graded materials and polymetallic materials; ②the research on compound finishing technology for complex inner channel with complex geometry, bifurcation, gradual capillary structure, topology and so on; ③the research on high-precision detection method for the finishing quality of inner channel and the three-dimensional reconstruction technology of geometric errors. Reference | Related Articles | Metrics

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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 （597）      PDF （6537KB）（344）       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

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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 （757）      PDF （2658KB）（338）       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

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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 Abstract （569）      PDF （7590KB）（335）       Knowledge map    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.  Reference | Related Articles | Metrics

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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 （460）      PDF （3792KB）（335）       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

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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 （543）      PDF （6100KB）（330）       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

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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 （272）      PDF （6293KB）（329）       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

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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 Abstract （625）      PDF （2807KB）（327）       Knowledge map    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.  Reference | Related Articles | Metrics

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Design of Cross-spring Flexure Hinges WU Hao, LI Zongxuan, ZHANG Defu, LI Qingya, LI Yunfeng, China Mechanical Engineering    2022, 33 (10): 1203-1209.   DOI: 10.3969/j.issn.1004-132X.2022.10.009 Abstract （407）      PDF （4097KB）（327）       Knowledge map    Save To realize the requirements of a certain optical instrument for flexural hinges， a new type of cross-spring flexural hinge was proposed， and the design method was studied by using the Castiglianos second theorem. First， the Castiglianos second theorem was used to derive the flexibility calculation formula of the cross-spring flexural hinges to determine the axial rigidity and rotational rigidity of the hinges. Then， a case design was carried out and the finite element analysis was used for simulation. Finally， an optical test platform was set up and the rotation stiffness of the example was measured. The results show that the analytical solution， the simulation solution and the experimental data are in good agreement， and the relative error is as 8.7%. Using the Castiglianos second theorem as a design tool， the designer may determine the dimensional parameters according to the rigidity and structural requirements of the cross-spring flexural hinges， and the design of the cross-spring flexural hinges provides a new approach method for other hinges.  Reference | Related Articles | Metrics

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Design and Experimental Study of a Flexible Winding Forming System for Carbon Fiber Reinforced Carbon/Carbon Crucible Preform WANG Zheng, DONG Jiuzhi, CHEN Yunjun, JIANG Xiuming, China Mechanical Engineering    2023, 34 (10): 1184-1190,1198.   DOI: 10.3969/j.issn.1004-132X.2023.10.007 Abstract （285）      PDF （5668KB）（321）       Knowledge map    Save In order to solve the problems of product consistency and low production efficiency caused by manually reinforced carbon/carbon crucible preforms， a flexible winding forming system of carbon fiber reinforced crucible preform was proposed. The line type design process of crucible core die for special rotary body structure with one end plane head and one end ellipsoid head was presented based on the non-geodesic method. Each module and implementation method of computer aided line type design were introduced， and the design line type was simulated. A special winding machine with four degrees of freedom was designed according to the winding characteristics. The control system of four-axis winding machine was designed based on programmable controller and touch screen， and the winding tests were carried out. It is indicated that the winding machine runs stably and the fiber may be wound continuously and stably on the surfaces of the core die， and the system may realize automatic winding of carbon fiber reinforced carbon/carbon crucible preforms.  Reference | Related Articles | Metrics

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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 （329）      PDF （5241KB）（320）       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

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Hysteresis and Dynamic Response of Magnetorheological Measuring Systems LYU Jingcheng, WEI Yintao, WU Mingyu, HE Junxiang, LIANG Guanqun, YIN Hang China Mechanical Engineering    2022, 33 (17): 2017-2023.   DOI: 10.3969/j.issn.1004-132X.2022.17.001 Abstract （397）      PDF （6330KB）（318）       Knowledge map    Save The control effectiveness of magnetorheological systems depended on the modeling， which was crucial for modeling hysteresis and dynamic response characteristics. By analyzing the hysteresis of each part of the magnetorheological systems excited by a control signal， the method of systematically studying the dynamic behavior of parts was known. By applying the excitation of DC and AC， dynamic response characteristics of the magnetorheological measuring systems were tested and studied. The results show that the current-shear stress relationship under the excitation of the unbiased harmonic current is a butterfly curve， which is caused by the response hysteresis， and the smooths upper and lower edges of the curve are caused by the hysteresis and the nonlinearity of the system， respectively. Finally， the hysteresis time is introduced to better describe the dynamic response relationship between currents and shear stresses in various situations， and the value is as 23.1 ms.  Reference | Related Articles | Metrics

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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 （494）      PDF （6637KB）（318）       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

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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 （608）      PDF （5879KB）（314）       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

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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 （509）      PDF （6394KB）（314）       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

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High-performance Paper-based Electronic Fabricated by Electric-field-driven Jet Micro 3D Printing#br# ZHANG Yongxia, ZHANG Guangming, ZHOU Longjian, ZHOU Hefei, XU Quan, LAN Hongbo China Mechanical Engineering    2022, 33 (10): 1244-1259.   DOI: 10.3969/j.issn.1004-132X.2022.10.014 Abstract （448）      PDF （6248KB）（313）       Knowledge map    Save A novel method of the electric-field-driven（EFD）jet deposition micro-scale 3D printing for fabricating high resolution circuit on paper-based surface was proposed. The basic principles and process flows of the proposed method were presented. The effects and rules of the main processing parameters（e. g.， the voltage， back pressure， printing speed） on the accuracy and quality of silver wires fabrications were revealed by a serial of experiments. Then， by using optimized parameters and the nano silver paste（75% silver content and 35 Pa·s（at 25 ℃）dynamic viscosity）， the micro/nano-scale structure with high resolution and high aspect ratio was fabricated by multi-layer stacking on three kinds of paper substrates. For example， the line width with 15 layers stacking on RC photo paper may be kept at 10 μm， and the aspect ratio may be increased to 6.33， causing the 94.8% decrease of the resistance. Finally， flexible electromagnetic actuators（FEMAs） and complex conductive patterns were fabricated on different paper substrates to prove the printing ability. The results show that the new method of EFD 3D printing technology combined with high viscosity and low temperature sintering nano silver paste may provide an effective way for high-performance paper-based electronics.  Reference | Related Articles | Metrics

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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 （311）      PDF （6340KB）（312）       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

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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 Abstract （494）      PDF （13411KB）（309）       Knowledge map    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. Reference | Related Articles | Metrics

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Dimensional Parameter Optimization of Planar Closed-loop Legged Mechanisms WANG Xianye, LIU Haitao, HUANG Tian China Mechanical Engineering    2022, 33 (11): 1261-1268.   DOI: 10.3969/j.issn.1004-132X.2022.11.001 Abstract （443）      PDF （6330KB）（303）       Knowledge map    Save Aiming at the foot trajectory outputs by Theo Jansens linkages, the dimensional parameters of a novel planar closed-loop legged mechanism were optimized. The kinematic models of the mechanism were derived using the Assur groups methods. According to the structural characteristics, the number of design variables was reduced to one by using the position limitation of a crank-rocker mechanism. A single-objective optimization problem was established by minimizing the minimal deviation of the foot trajectories of two mechanisms subjected to the geometric constraints of the dimensional parameters. This problem was solved by the one-dimensional search method, leading to the design and fabrication of an eight-leg mobile robot. The feasibility of the design was verified by experimental results. Reference | Related Articles | Metrics

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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 Abstract （529）      PDF （5495KB）（297）       Knowledge map    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. Reference | Related Articles | Metrics

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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 （524）      PDF （5740KB）（297）       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

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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 （468）      PDF （6050KB）（294）       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

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Research on Thermal Characteristics of Motorized Spindles Based on Digital Twin XU Rongfei, FAN Kaiguo China Mechanical Engineering    2022, 33 (16): 1965-1971.   DOI: 10.3969/j.issn.1004-132X.2022.16.010 Abstract （464）      PDF （5079KB）（289）       Knowledge map    Save  In order to improve the simulation accuracy of thermal characteristics， adigital twin-based simulation method for thermal characteristics was proposed. The physical space of digital twin for thermal characteristics of a motorized spindle was built based on the IoT data acquisition system. A digital twin system for thermal characteristics was developed based on Java， ANSYS and MATLAB. Correction models of thermal boundary conditions were proposed based on the temperatures of thermal key points. Data mapping between physical space and virtual space and digital twin for thermal characteristics of motorized spindles were realized using the proposed method. Experimental results show that the simulation accuracies of temperature field and thermal deformation are as 98% and 95% respectuely using the proposed digital twin-based simulation method for thermal characteristics， which effectively improves the accuracy of finite element analysis of thermal characteristics.  Reference | Related Articles | Metrics