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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 （992）      PDF（pc） （7794KB）（1407）       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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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 （1907）      PDF（pc） （5000KB）（1208）       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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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 （936）      PDF（pc） （9652KB）（969）       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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Multi Tooth Meshing Characteristics and Load Bearing Contact Analysis Method of Cycloidal-pin Wheels WANG Yongqiang, WEI Bingyang, XU Jiake, YANG Jianjun China Mechanical Engineering    2023, 34 (10): 1151-1158.   DOI: 10.3969/j.issn.1004-132X.2023.10.003 Abstract （867）      PDF（pc） （4467KB）（954）       Knowledge map    Save  The tooth profile equations of cycloidal gear were derived by the envelope methods， and the tooth surface contact parameters were obtained. An accurate algorithm for the geometry analysis of the backlash was proposed， which solved the defects that the traditional backlash algorithm might only be used for the constant displacement modification. The tooth by tooth clearance elimination methods were used to solve the deformation compatibility equation， which avoided the error and uncertainty of conventional meshing analysis and improved the calculation accuracy and efficiency of load-bearing contact analysis. The complete calculation flow from tooth surface contact analysis to load contact analysis was given， and the accurate load parameters of any angle position and different modification methods were obtained.  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 （1729）      PDF（pc） （5220KB）（936）       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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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 （1440）      PDF（pc） （50387KB）（935）       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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Research Advances in Chatter of Metal Cutting Systems Involving Time Delays REN Yongsheng, YAO Donghui, ZHANG Jinfeng China Mechanical Engineering    2023, 34 (21): 2548-2567,2576.   DOI: 10.3969/j.issn.1004-132X.2023.21.004 Abstract （893）      PDF（pc） （9923KB）（878）       Knowledge map    Save Metal cutting processes typically had distinct characteristics of delayed system.  Chatter phenomenon was a highly complex phenomenon which widely occured in various metal cutting processes.  Chatter prediction in cutting processes was the premise of chatter suppression.  The theoretical method for chatter prediction， in-process recognition techniques for chatter prediction， and influencing factors for metal cutting dynamics were reviewed.  Applications of machine tool structure materials were introduced.  Some problems and research directions in future were proposed.  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 （868）      PDF（pc） （9794KB）（858）       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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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 （1037）      PDF（pc） （2405KB）（837）       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 （1563）      PDF（pc） （5740KB）（814）       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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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 （995）      PDF（pc） （5241KB）（812）       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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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 （1065）      PDF（pc） （1793KB）（783）       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）

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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 （1024）      PDF（pc） （6293KB）（783）       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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A High-dimensional Uncertainty Propagation Method Based on Supervised Dimension Reduction and Adaptive Kriging Modeling SONG Zhouzhou1, 2, ZHANG Hanyu1, 2, LIU Zhao3, ZHU Ping1, 2 China Mechanical Engineering    2024, 35 (05): 762-769，810.   DOI: 10.3969/j.issn.1004-132X.2024.05.001 Abstract （2042）      PDF（pc） （3068KB）（765）       Knowledge map    Save  High-dimensional uncertainty propagation currently faced the curse of dimensionality, which made it difficult to utilize the limited sampling resources to obtain high-precision uncertainty analysis results. To address this problem, a high-dimensional uncertainty propagation method was proposed based on supervised dimension reduction and adaptive Kriging modeling. The high-dimensional inputs were projected into the low-dimensional space using the improved sufficient dimension reduction method, and the dimensionality of the low-dimensional space was determined by using the Ladle estimator. The projection matrix was embedded into the Kriging kernel function to reduce the number of hyperparameters to be estimated and improve the modeling accuracy and efficiency. Finally, the leave-one-out cross-validation error of the projection matrix was innovatively defined and the corresponding Kriging adaptive sampling strategy was proposed, which might effectively avoid large fluctuations of model accuracy in the adaptive sampling processes. The results of numerical and engineering examples show that, compared with the existing methods, the proposed method may obtain high-precision uncertainty propagation results with fewer sample points, which may provide references for the uncertainty analysis and design of complex structures.  Reference | Related Articles | Metrics | Comments（0）

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Research Status and Development Trends of Large Wind Turbine Main Shaft Sliding Bearings ZHU Caichao1, ZHANG Ronghua1, SONG Chaoshen1, TAN Jianjun1, YANG Liang2 China Mechanical Engineering    2024, 35 (10): 1711-1721.   DOI: 10.3969/j.issn.1004-132X.2024.10.001 Abstract （1386）      PDF（pc） （4422KB）（762）       Knowledge map    Save The pace of large wind turbine units was accelerating, and the reliability of core components was increasingly important for wind turbine operations. Sliding bearings had the advantages of high load capacity, long life, easy maintenance, scalability and small size, and they had advantages and great potential for the reliable replacement of wind turbine main bearings key components produced at home. The problems of main shaft rolling bearings in high-power wind turbines and the advantages of using sliding bearings on the main shaft were analyzed herein. The technical methods and application status of wind turbine main shaft sliding bearing design, materials, lubrication, and experimental verification were present in detail, and the existing problems of high-power wind turbine main shaft sliding bearings and future development trends were summarized. It is expected to provide reference for the digital design and industrial development of high-power wind turbine main bearings. Reference | Related Articles | Metrics | Comments（0）

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Cross-domain Fault Diagnosis of Bearings Based on Discriminant Feature Extraction and Dual-domain Alignment DONG Shaojiang, ZHOU Cunfang, CHEN Lili, XU Xiangyang China Mechanical Engineering    2023, 34 (15): 1856-1863.   DOI: 10.3969/j.issn.1004-132X.2023.15.010 Abstract （1083）      PDF（pc） （4455KB）（750）       Knowledge map    Save  A deep transfer learning method was proposed to address the challenge of inconsistent feature distributions and difficulties in removing noise components in vibration data collected under different operating conditions for rolling bearings. The method utilized a combination of discriminative feature extraction and dual-domain alignment. Firstly， the labeled vibration signals and unlabeled vibration signals were segmented into fixed-length data sets using a data segmentation method. To mitigate the interference of noise signals in practical operating conditions， a channel attention mechanism known as SENet was employed. Additionally， a discriminative loss term was incorporated to assist the feature extractor in extracting features that exhibit discriminative properties. To handle the issue of inconsistent data feature distributions， the MMD was utilized to align the global domain distributions between the source and target domains. Furthermore， conditional adversarial learning techniques were employed to align the sub-domain distributions， resulting in dual-domain alignment. Experimental validation was conducted on two publicly available rolling bearing fault datasets collected under different operating conditions. The results show that the proposed method achieves an average recognition accuracy of over 98%. Comparative analyses with different diagnostic methods further demonstrate the effectiveness and superiority of the proposed method.  Reference | Related Articles | Metrics | Comments（0）

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Study on Force Model and Surface Integrity of Cylindrical Grinding 18CrNiMo7-6 Steels WANG Dong, CHEN Lei, ZHANG Zhipeng China Mechanical Engineering    2024, 35 (03): 381-393.   DOI: 10.3969/j.issn.1004-132X.2024.03.001 Abstract （1031）      PDF（pc） （8185KB）（728）       Knowledge map    Save  In order to accurately and effectively control the influences of grinding parameters on grinding force and surface integrity, a three-stage grinding force theoretical model was established based on the plastic deformation, indentation theory and shear strain effect between abrasive particles and materials by analytical method. The brown corundum grinding wheels were selected for grinding experiments to explore the effects of grinding parameters on grinding force and the effects of grinding parameters and grinding force on surface integrity. The optimal processing parameters for cylindrical grinding were obtained through orthogonal experiments of cylindrical transverse grinding. The results show that the average prediction errors of normal and tangential grinding forces in the cylindrical grinding force model are 5.56% and 7.08%, respectively. The radial feed speed of the grinding wheel has the greatest impact on grinding force, followed by grinding width, and the influences of workpiece speed and grinding wheel particle size are relatively small. The radial feed speed and grinding width of the grinding wheel have a significant impact on residual stress, and the particle size of the grinding wheel has the greatest impact on surface roughness. As the grinding force increases, the surface roughness value continuously increases, and the residual stress firstly decreases and then increases. The maximum residual stress value along the depth direction firstly increases and then decreases. Within the parameters taken in the experiments, the distribution range of residual stress is basically 20~40 μm. The optimal combination of processing parameters is a radial feed speed of 0.15 mm/min for the grinding wheel, a workpiece speed of 120 r/min, a grinding width of 10 mm, and a grinding wheel particle size of 80. 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 （1066）      PDF（pc） （6422KB）（724）       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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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 （1210）      PDF（pc） （3896KB）（714）       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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Time-optimal Trajectory Planning of 6-RUS Parallel Robots Based on Grid Search Algorithm LIU Dongcai, DONG Guangyu, DU Yuhong, LI Wenpeng, China Mechanical Engineering    2023, 34 (13): 1589-1598.   DOI: 10.3969/j.issn.1004-132X.2023.13.008 Abstract （862）      PDF（pc） （7882KB）（676）       Knowledge map    Save Aiming at the problems of uneven reproducing trajectory and low trajectory planning efficiency of 6-RUS parallel painting robots， a trajectory planning method of optimal time of 6-RUS parallel painting robots was proposed based on optimizing the position of Bézier curve nodes. Firstly， the preprocessed trajectory was discretized to grid points， the node parameters were updated and the arc length of Bézier curve was optimized， and the path of small line segment was further fitted to obtain the optimal geometric path. Then， the optimal velocity corresponding to different coarse grid points and the solution time were calculated， and the appropriate coarse grid points were selected. The paths between grid points were further densified by small steps， and the forward and backward maximum velocity were iteratively solved. The maximum feasible velocity curve of the path was searched to obtain the optimal running time of the 6-RUS parallel robots. Finally， the experiments were carried out on a self-developed 6-RUS parallel robot platform. The results show that under the same teaching trajectory， the path length of the improved Bessel curve algorithm herein is as 8.12 m， which is better than that of traditional Bézier curve and G2CBS（G2 continuous cubic Bézier spiral）aigorithm. Meanwhile， the improved time-optimal path parameterization algorithm herein was used for the optimized teaching path. The solution time of the optimal velocity curve of the algorithm herein is as 416.4 ms， which is 244.7 ms less than that of TOPP-RA algorithm. Moreover， the time-optimal trajectory planning time of the algorithm herein is also better than that of TOPP-RA algorithm. The method improves the solving speed of the optimal velocity， shortens the track reproduction time of 6-RUS parallel robots， and improves the working efficiency.  Reference | Related Articles | Metrics | Comments（0）

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Inverse Kinematics Solution of Robots Based on IQPSO Algorithm CHEN Zhuofan, ZHOU Kun, QIN Feifei, WANG Binrui China Mechanical Engineering    2024, 35 (02): 293-304.   DOI: 10.3969/j.issn.1004-132X.2024.02.014 Abstract （1380）      PDF（pc） （9273KB）（674）       Knowledge map    Save Aiming at the problems of singular pose, non-unique solution and low solution precision in the inverse kinematics solution processes of general robots, an improved quantum particle swarm optimization algorithm was proposed. Firstly, the robot kinematics model was established by using the D-H parameter method, and the minimum pose errors at the end of the manipulators were the main optimization goal, and the constraints of the minimum joint angle changes before and after the movement and the smooth and continuous stroke were added, and the objective function was designed. Secondly, an IQPSO algorithm was designed by using the Levy flight strategy to improve the particle update method, nonlinear dynamic adjust the shrinkage and expansion factors, and using the variable weight method to calculate the optimal average position. Then, the simulation and comparison experiments of three algorithms（IQPSO,APSO,QPSO） were carried out by simulating two different solutions of single point pose and continuous trajectory. The results show that the IQPSO algorithm has the advantages of fast convergence speed and high solution accuracy; finally, the IQPSO algorithm was used in the body of the robot arm for physical verification. The results show that the trajectory composed of interpolation points obtained by the IQPSO algorithm is continuous and smooth, which further proves the stability and feasibility of the algorithm in practical motion control. Reference | Related Articles | Metrics | Comments（0）

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Identification of Position-independent Geometric Errors for Rotary Axes of Five-axis Table-tilting Machine Tools LIANG Xiaobing, LU Yaoan, WANG Chengyong, China Mechanical Engineering    2023, 34 (21): 2585-2591.   DOI: 10.3969/j.issn.1004-132X.2023.21.007 Abstract （917）      PDF（pc） （5263KB）（644）       Knowledge map    Save  PIGEs of rotary axes were the important factors that affected the machining accuracy of five-axis machine tools. Taking AC type five-axis table-tilting machine tools as an example， an identification method of PIGEs of rotary axes was proposed based on the differential evolution algorithm. Firstly， a mathematical model of PIGEs and length change of ball bar was established. The initial PIGEs may be identified by existing methods. Then， an optimization objective function was defined， and the PIGEs of the rotary axes were optimized as a whole by a differential evolution algorithm to improve the identification accuracy of the rotary axes PIGEs. The experimental and simulation results show that the proposed method may effectively improve the identification accuracy of the PIGEs of the rotary axes.  Reference | Related Articles | Metrics | Comments（0）

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Flexible Skin-shaped Optical Fiber Reconstruction Method for Allomorphic Aircrafts WANG Yuanfeng, ZHU Lianqing, HE Yanlin, ZHOU Kangpeng, China Mechanical Engineering    2023, 34 (15): 1873-1880.   DOI: 10.3969/j.issn.1004-132X.2023.15.012 Abstract （758）      PDF（pc） （5104KB）（636）       Knowledge map    Save  Large-scale deformation monitoring of allomorphic aircrafts in the flight processes was a research difficulty and hot spot in the aerospace field， and the existing methods were difficult to achieve high-precision three-dimensional deformation monitoring during the flight of the aircrafts. Aiming at this problem， a flexible skin-shaped fiber reconstruction method for a variant aircraft was proposed based on optical fiber sensing to achieve deformation monitoring during flight of the aircrafts. Based on the principle of fiber grating strain sensing， the relationship between fiber strain and curvature was derived， the conversion matrix between the local coordinate system and the global coordinate system of optical fiber sensing was established， the conversion of fiber measurement point coordinates to the global coordinate system was realized， and the three-dimensional deformation reconstruction algorithm was studied based on curve fitting according to the spatial curve fitting method. At the same time， in order to reduce the measurement errors of the fiber optic sensors， the calibration tests of the fiber optic sensors were carried out to obtain the strain sensitivity of the sensors. In order to verify the effectiveness of the proposed method， the three-dimensional deformation reconstruction of flexible skin samples under different curvatures was tested experimentally. Experimental results show that the average error of the shape reconstruction method is as 3.5% and the minimum error is less than 2.1% in the deformation ranges of 0～15.38 m-1 curvature of flexible skin samples. The proposed method has a good application prospect in aerospace and other fields.  Reference | Related Articles | Metrics | Comments（0）

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Operating Mechanism and Data Driven Approach for Fault Alarm of Wind Turbine Gearbox Systems MENG Kang, TENG Wei, PENG Dikang, XIANG Ling, LIU Yibing China Mechanical Engineering    2023, 34 (12): 1476-1485.   DOI: 10.3969/j.issn.1004-132X.2023.12.010 Abstract （1137）      PDF（pc） （9342KB）（625）       Knowledge map    Save Traditional machine learning methods were used in fault early warning of wind turbine gearboxes, the models were usually designed only by studying the relationship between data and faults, and the selection of parameters and model structure were lack of physical basis, resulting in poor interpretability and weak generalization capabilities of the models. The structure and actual operation control mode of the wind turbine gearbox were studied, the relationship between the operation mechanism and the data of corresponding supervisory control and data acquisition system was analyzed, and the operation data change trend was given qualitatively followed by deterioration of the typical gearbox faults. Finally, a series of one-class support vector machine(OCSVM) based models were constructed according to change law of the data distribution to realize the early fault warning of the wind turbines gearbox systems. Experimentsal results show that all of the proposed models may locate the fault positions of the wind turbine gearbox systems, which has clear physical significance.  Reference | Related Articles | Metrics | Comments（0）

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Integrated Casting Triangular Beam Lightweight Improving with Multi-performance Constraints of Body Systems SU Yonglei, ZHANG Zhifei China Mechanical Engineering    2024, 35 (04): 691-699.   DOI: 10.3969/j.issn.1004-132X.2024.04.012 Abstract （1072）      PDF（pc） （6363KB）（623）       Knowledge map    Save  An optimization method of integrated casting structures was constructed systematically, and based on the super-element model of body system, body casting part lightweight improving with multi-performance constraints was realized. Firstly, complex body systems were reduced, the sub-system division principle and method were proposed for continuous body structure. Super-element reduction of the sub-system was conducted to ensure analysis accuracy and improve calculation efficiency, laying the foundation for rapid optimization. Secondly, performances of casting structures and body systems were considered simultaneously, the compromise programming methods were used to normalize static and dynamic sub-targets and construct the comprehensive objective function, weight coefficients of sub-targets were obtained by analytic hierarchy process(AHP), and then multi-model topology optimization was carried out to determine position distribution of reinforcements. Furthermore, designability and manufacturability were considered simultaneously, parametric definition of variable thickness drawing surface of casting structure was carried out, manufacturing constraints were applied during optimization processes, and then thickness parameter design was completed based on combined surrogate model. The results show that, under the premise of ensuring the analysis accuracy, reduced body system models improve computing efficiency greatly, and save 97.3% of computing resources. Casting triangular beam lightweight may be achieved while improving related performance by conducting structure optimization, which indicates correctness and practicability of the proposed method.  Reference | Related Articles | Metrics | Comments（0）

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High Rigidity and Lightweight Design of Purlins in Photovoltaic Tracker Bracket DONG Xiaohu, WANG Shitao, ZHOU Dechun China Mechanical Engineering    2023, 34 (10): 1207-1213.   DOI: 10.3969/j.issn.1004-132X.2023.10.010 Abstract （1404）      PDF（pc） （5559KB）（617）       Knowledge map    Save In the intelligent photovoltaic tracker brackets， cold-formed purlins were used to support the photovoltaic panels， and located spannig the horizontal single-axis and the module frame. Firstly， the minimum compliance of the structures was taken as the target and relative densities of elements were taken as the design variables， and the topology optimum design models were constructed under the given volume and the first natural frequency constraints. Optimal material distributions of the purlins were obtained based on SIMP (solid isotropic material with penalization) method， and this topology optimization structure was engineering designed and manufactured. Then， test load conditions were designed according to the practical environment where the photovoltaic tracker brackets were applied under different wind loads. The static and dynamic finite element analyses of the original and optimized purlins were carried out respectively， the simulation results show that the optimized purlins are improved in terms of bending resistance， torsion resistance， and natural frequency. Thus， the effectiveness of the optimization design method is verified. After that， the optimal purlins whose mass is reduced by 8.8% were also manufactured by engineering methods， and the mechanics performances were verified by the experiments.  Reference | Related Articles | Metrics | Comments（0）

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Research on Energy Transfer Model and Optimisation of Operating Parameters of Vibratory Rollers HUI Jizhuang, LUO Wei, ZHANG Zeyu, ZHANG Jun, WANG Jie China Mechanical Engineering    2024, 35 (03): 541-547.   DOI: 10.3969/j.issn.1004-132X.2024.03.016 Abstract （734）      PDF（pc） （1996KB）（594）       Knowledge map    Save  In order to improve the compaction quality of vibratory rollers, the energy transfer model of vibratory rollers and the optimisation of operating parameters were studied. Firstly, the system vibration dynamics model of “wheel-compacted material” was established based on the U-K equation, and the energy transfer model of vibratory roller was proposed in combination with energy conservation.Then, the vibration frequency and compaction speed were taken as the optimal working parameters to construct the optimisation model of road compaction quality.Finally, the feasibility and effectiveness of the proposed method were proved through case verification. The results show that: the ratio between the working frequency and the intrinsic frequency of the compacted material is kept within the range of 2～2 to avoid the effect of resonance.The initial stage of low-speed rolling, and after the material properties were stabilised, the rolling speed may be increased to ensure efficient compaction, which results in the vibration frequency in the range of 21.8～27 Hz and the compaction speed in the range of 2.36～2.91 km/s, to achieve the optimal compaction effectiveness. The proposed energy transfer model and operation parameter optimisation model lay a foundation for guaranteeing the compaction quality of vibratory rollers and provide a reference for improving the compaction quality and efficiency of vibratory rollers. Reference | Related Articles | Metrics | Comments（0）

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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 （837）      PDF（pc） （5668KB）（588）       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 | Comments（0）

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Design and Analysis of a Novel Weak-coupling Parallel Hip Exoskeleton with Large Angle of Rotation XU Jilong, LIU Fucai, NIU Yunzhan China Mechanical Engineering    2023, 34 (21): 2540-2547.   DOI: 10.3969/j.issn.1004-132X.2023.21.003 Abstract （733）      PDF（pc） （7047KB）（586）       Knowledge map    Save A novel bio-syncretic hip exoskeleton with large-angle and weak-coupling characteristics was proposed to solve the problems such as small workspace， difficult forward kinematics modeling， and complex control of parallel hip exoskeletons. The detailed structures of two-stage prismatic joint were designed， and the expression for calculating the slope of the groove was obtained. The man-machine complexs forward and inverse position solutions were derived by closing-vector-circle method. The inverse Jacobian matrix was obtained by taking the derivative of the inverse position solution equation. Performance analysis shows that the man-machine complex has the advantages such as large range motion， no internal singularities， good force transfer performance， and easy control. Reference | Related Articles | Metrics | Comments（0）

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Review on Management at Mechanical Design and Manufacturing Discipline of National Natural Science Foundation of China in 2023 YE Xin, HUANG Zhiquan, ZHANG Junhui, China Mechanical Engineering    2024, 35 (04): 571-579.   DOI: 10.3969/j.issn.1004-132X.2024.04.001 Abstract （807）      PDF（pc） （8141KB）（586）       Knowledge map    Save  The applications, evaluations, and funding of several types of projects that were classified into the talent and exploratory funding categories at mechanical design and manufacturing discipline (division Ⅱ of engineering science) of the National Natural Science Foundation of China in 2023, as well as the research progresses and findings 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 2024 was introduced． Reference | Related Articles | Metrics | Comments（0）

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Analysis and Test on Dynamic Transmission Errors of RV Reducers under Load Conditions XU Lixin, XIA Chen, YANG Bo China Mechanical Engineering    2023, 34 (18): 2143-2152.   DOI: 10.3969/j.issn.1004-132X.2023.18.001 Abstract （1002）      PDF（pc） （8485KB）（585）       Knowledge map    Save  For the current RV reducer transmission accuracy factory calibration value was detected under no-load conditions, it was difficult to reflect the real accuracy performance under torque loading conditions, in order to effectively reveal the dynamic transmission error characteristics of the RV reducers under the action of the load, a theoretical dynamic model of contact multi-body system of standard RV reducer with two crankshafts was proposed, which took the multi-error factors of geometry and position of key transmission parts into consideration. In order to effectively reveal the dynamic transmission error characteristics of RV reducers under load, during modeling, firstly, the parametric model of the whole reducer was designed and completed for the RV reducer transmission structure characteristics. Secondly, a detailed dynamic contact analysis method was proposed considering involute gear drive of the first stage, cycloidal-pin drive of the second stage, and multiple sets of turning-arm bearings and support bearings. Thus, the dynamic transmission error characteristics of reducer under torque load were discussed taking RV20E as the object. The results show that with the increase of load torque, the transmission error amplitudes of reducer are increasing, but the amplitude growth rate is decreasing. Compared with no-load conditions, the increase of theoretical transmission errors of the reducers under rated torque is as 73.1%, and the increase of experimental transmission errors under rated torque is as 58.9%. Reference | Related Articles | Metrics | Comments（0）

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Modeling and Experimental Research of Ground Workpiece Surface Topography after Grinding with Structured Grinding Wheels YI Jun, YI Tao, CHEN Bing, DENG Hui, ZHOU Wei, China Mechanical Engineering    2023, 34 (22): 2711-2720.   DOI: 10.3969/j.issn.1004-132X.2023.22.008 Abstract （881）      PDF（pc） （9016KB）（584）       Knowledge map    Save  The rough surface modeling method was employed to establish the surface topography model of a straight groove structured grinding wheel, considering the influences of structural characteristic parameters on the continuity of the grinding wheel surface through actual measurements. Based on the kinematics relationship between the grinding wheel and workpiece, as well as the trajectory equation of cutting edge, a prediction model for workpiece surface topography after grinding was formulated. Grinding experiments were conducted using both electroplating CBN and brazing CBN straight groove structured grinding wheels. The results show that relative errors between predicted Ra values and experimental ones are below 10%, while relative errors between predicted Rz values and experimental ones are below 12%, thereby validating the accuracy of the prediction model. Furthermore, the influences of various structural parameters on the surface topography of the workpiece were investigated. When the groove width of the grinding wheel remaines constant, an increase in the intermittent ratio of the grinding wheel resultes in an elevation of workpiece surface roughness. Conversely, when the intermittent ratio is held constant, variations in groove width have a minimal effect on workpiece surface roughness. Additionally, it is observed that roughness of the grinding wheel itself is a significant factor determining ground workpiece surface roughness. Among the three characteristic parameters of the grinding wheel surface topography investigated herein, it is observed that the skewness of the grinding wheel surface height exerts the most significant influence on the ground workpiece surface roughness. Reference | Related Articles | Metrics | Comments（0）

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Multi-axis Fatigue Life Analysis Method for Welded Structures of Transmission Intermediate Shafts CAO Leilei, KANG Fanjun, GUO Chengchen, SONG Xuding, LYU Wenche China Mechanical Engineering    2023, 34 (13): 1605-0610,1627.   DOI: 10.3969/j.issn.1004-132X.2023.13.010 Abstract （660）      PDF（pc） （5864KB）（551）       Knowledge map    Save The transmission system of heavy-duty vehicles had the characteristics of large speed ratio and large torque. The welded structures of transmission intermediate shafts carried complex working loads， and multiaxial fatigue failure was easy to occur at the weld seams. In order to evaluate the fatigue life more accurately and effectively， a fatigue life analysis method for the welded structures of transmission intermediate shafts of heavy-duty vehicles was proposed based on the multi-axial structural stress method. First， the finite element model with weld details for the welded structures of transmission intermediate shafts was built. Then， the time history of the structural stress components at the fatigue hazard points of the welds was solved， the load path was synthesized on the structural stress planes to obtain the equivalent stress range of the non-proportional loading path. Finally， the fatigue life was determined by combining the main S-N curve. This method was used to evaluate the fatigue life of the weld roots and weld toes of the welded structures of transmission intermediate shafts， and the results were compared with those of the fatigue bench tests. Results show that the predicted damage location and fatigue life are both in good agreement with the experiments， and the differences between the fatigue life of the weld roots and toes are consistent with the multi-axial fatigue test results in the existing literature， which indicating that the proposed multi-axial structural stress method is reliable for the fatigue life assessment of the welded structures of transmission intermediate shafts.  Reference | Related Articles | Metrics | Comments（0）

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Design of Lane Keeping Assist Systems Based on Improved Preview Control Model LIANG Yongbin, FU Guang, LIN Zhigui, HE Zhicheng, ZHANG Jialuo, CHEN Tao China Mechanical Engineering    2024, 35 (03): 548-558.   DOI: 10.3969/j.issn.1004-132X.2024.03.017 Abstract （885）      PDF（pc） （8767KB）（550）       Knowledge map    Save To address the issues of low robustness, consistency in vehicle manufacturing, and severe road surface interference in LKA system of torque control, a LKA system was designed based on angle control by using neural network technology, Autofix algorithm, and preview feedback control theory, through expected trajectory decision-making and following PID control algorithm. A hardware-in-the-loop simulation test platform was built to verify the effectiveness and accuracy of the design of the angle based lane protection systems through virtual simulation based on Carsim/Veristand/ MATLAB. Based on GB/T 39323—2020, CN-CAP—2021, Euro-NCAP—2022 and the testing requirements of the car retention systems based on real-road commissioning and user concern scenarios, the simulation and comparison with real-road scenarios show that the angle-controlled LKA system has better lane keeping capability, stability, adaptability and robustness than that of the torque-controlled LKA system in the same usage scenarios. Reference | Related Articles | Metrics | Comments（0）

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Visual Detection of Subsurface Corrosions in Ferromagnetic Metal Plates Using Pulsed Eddy Current Based on Dual-sensor Differential Mechanism WANG Jin1, LI Yong1, SU Bingjie1, GAO Wenlong1, XIANG Yi1, 2, LIU Zhengshuai1, CHEN Zhenmao1 China Mechanical Engineering    2025, 36 (03): 381-390.   DOI: 10.3969/j.issn.1004-132X.2025.03.001 Abstract （811）      PDF（pc） （17686KB）（550）       Knowledge map    Save A pulse eddy current visual detection method was proposed based on a dual-sensor differential mechanism for subsurface corrosions in ferromagnetic metal plates. In this method, a dual-sensor differential probe was used to pick up the pulsed eddy current testing signals, and the slope of the logarithmic curve along the falling edge of the testing signals and the peak value of the normalized differential signals were extracted as signal features, which were used for visual detection of defects of different sizes. Through simulation and experimental research, the correlation laws between the proposed signal features and the sizes of defects were established, and it is verified that the dual-sensor differential probe has the advantages of reducing noise interference and improving the detection sensitivity compared with traditional single-sensor probes. In addition, a method was proposed to fuse the two signal features, and the results indicate that the defect images using fused signal features have a higher image signal-to-noise ratio. The research method proposed herein provides an effective and reliable solution for the visual detection of subsurface corrosions in ferromagnetic metal plates. Reference | Related Articles | Metrics | Comments（0）

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Calculation Method of LCA Parameters for Green Design and Assessment Collaboration of Electromechanical Products YAN Meng, LI Tao, YANG Chen, WANG Mingyu, YANG Dongdong China Mechanical Engineering    2023, 34 (12): 1453-1464.   DOI: 10.3969/j.issn.1004-132X.2023.12.008 Abstract （863）      PDF（pc） （7115KB）（547）       Knowledge map    Save In order to collaboratively analyze the green design and assessment processes of electromechanical products, the correlation mapping between green design and life cycle stages was established using the modeling method of multi-domain correlation of product design domain, life cycle activity domain and environmental impact assessment domain. The life cycle activity domain was correlated with the environmental impact assessment domain through the calculation method of life cycle assessment parameters.The LCA calculation tool was developed, and the calculation method of LCA parameters was applied to the whole life cycle stage of product green design. When the green design information was changed, just adjusting the corresponding parameters in the calculation tool, the environmental impact could be obtained after the design information was changed in real time, so as to help designers to re-design the product to green design. CWT3300D-165 wind turbine was used as a typical electromechanical product for application verification, and a product structure tree was established to calculate the environmental impact of the whole machine, components and parts of the product. From the calculation results, it may be seen that the two first-level components, foundation and nacelle, have the most serious environmental impact and need to focus on greenness in the product design stages and improve the green design scheme. Reference | Related Articles | Metrics | Comments（0）

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Research on Dynamic Modeling and Solving Method of Integrated Transmission System under Time-varying Conditions ZHANG Dingge, WANG Liyong, LI Le, ZHANG Jinle China Mechanical Engineering    2023, 34 (22): 2665-2673.   DOI: 10.3969/j.issn.1004-132X.2023.22.003 Abstract （784）      PDF（pc） （3130KB）（546）       Knowledge map    Save In order to meet the demands of real time monitoring of load characteristics and the demands of health management of the special vehicle integrated transmission system under actual complex conditions， by using the matrix analysis method and numerical solution method of planetary transmission mechanisms， and taking the real vehicle sensor data as the model input， a dynamic model of integrated transmission system was established to rapidly and continuously solve the transmission output speed and torque under time-varying conditions. The kinematic matrix， differential equation and torque balance equation of the planetary transmission mechanisms were constructed. The fast continuous solution method of the dynamic model under time-varying conditions and the method for solving road load under the conditions of missing road load information were proposed. The calculated transmission output speed and torque were compared with the bench test results under the three typical conditions of launching， shifting and acceleration. The results show that the dynamic model may realize the dynamic simulation calculation of the output characteristic of the integrated transmission under the conditions of missing road load information. It provides support for real-time monitoring， dynamic control and intelligent operation and maintenance of special vehicle integrated transmission systems.  Reference | Related Articles | Metrics | Comments（0）

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Depth of Cut Control for Thin-walled Parts in Robotic Milling Based on FLADRC SHI Long, ZHOU Hexiang, LI Zhoulong China Mechanical Engineering    2025, 36 (04): 671-680.   DOI: 10.3969/j.issn.1004-132X.2025.04.003 Abstract （2533）      PDF（pc） （8675KB）（544）       Knowledge map    Save Weakly rigid large thin-walled parts had large deformations and vibrations during robotic thinning machining, which led to a degradation of the surface quality of the workpieces and difficulties in ensuring the accuracy of the remaining wall thickness. To this end, a VCM-driven follower support head was used for vibration and deformation suppression, and a FLADRC based control strategy was proposed for depth of cut of robotic milling thin-walled parts. In order to verify the effectiveness of the control strategy, the system control models were firstly established based on the MATLAB/Simulink simulation and experimental platform, and the simulation analysis was carried out, then experimental verification was carried out on the thin-walled parts robotic milling experiment platform. Both of the simulation and experimental results show that the depth-of-cut control strategy based on the follower support head may significantly suppress the vibrations and deformations during the machining processes of thin-walled parts and effectively ensure the accuracy of the remaining wall thickness. In addition, compared with the traditional fuzzy PID control, the FLADRC has a better control effectiveness and exhibits higher robustness in the presence of external disturbances. Reference | Related Articles | Metrics | Comments（0）

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Nanosecond Laser Machining of Spiral Grooves of Dry Gas Seal Rotational Ring Surfaces Wenqian LI, Zhanqiang LIU, Jinfu ZHAO, Bing WANG, Yukui CAI China Mechanical Engineering    2025, 36 (10): 2207-2214.   DOI: 10.3969/j.issn.1004-132X.2025.10.006 Abstract （543）   HTML （76）    PDF（pc） （3972KB）（544）       Knowledge map    Save An experimental study on the nanosecond laser processing of the spiral groove on the dry gas seal rotational ring surfaces made of GH4169 was carried out. Orthogonal tests and one-factor methods were utilized to reveal the effects of laser power， scanning speed， filling spacing and repetition frequency on the spiral groove depth and bottom roughness Ra， and to determine the appropriate combination of laser processing parameters. The results show that the greatest influence on the depth of the spiral grooves on the surfaces of GH4169 alloy is the laser power， followed by the repetition frequency and the scanning speed， and the greatest influence on the roughness of the groove bottoms is the scanning speed， followed by the repetition frequency and the scanning spacing. With the laser power of 18 W， scanning speed of 40 mm/s， fill spacing of 0.005 mm， and repetition frequency of 50 kHz， the spiral grooves on the machined rotational ring surfaces is able to meet the machining requirements of groove depth of 7 μm， and groove bottom roughness of Ra≤0.8 μm. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Robot Welding Trajectory Planning and High Frequency Control for Curved Seams WU Chaoqun, ZHAO Song, LEI Ting China Mechanical Engineering    2023, 34 (14): 1723-1728.   DOI: 10.3969/j.issn.1004-132X.2023.14.009 Abstract （1555）      PDF（pc） （6070KB）（540）       Knowledge map    Save In a robotic real-time seam tracking system, the trajectory planning and control delay affected the tracking accuracy and welding quality. To solve this problem, a piecewise real-time trajectory planning and control method for curved seams was proposed by combining B-spline curve interpolation algorithm and EGM module. Firstly, the trajectory was segmented according to the principle of optimal interpolation time. Secondly, three times non-uniform B-spline was used to interpolate each trajectory to obtain the interpolation points. Finally, the high-frequency controller of the robot was designed. The interpolation points were sent to the robot by EGM module in a cycle of 4 ms to guide the robot movements. The experimental results show that this method may complete the planning of sine curve weld and guide the robot welding in 100 ms, and the tracking errors were controlled within ±0.2 mm, which realizes the rapid trajectory planning and high-frequency control. Reference | Related Articles | Metrics | Comments（0）