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  • JIN Guoguang, WEI Zhan, QIN Kaixuan, ZHANG Yangyan
    Journal of Mechanical Engineering. 2015, 51(13): 227-234. https://doi.org/10.3901/JME.2015.13.227
    High-speed cam mechanism is widely used in vehicles, textile machinery, printing machinery etc. The research of dynamic analysis is the basis and key point to improve the mechanical properties. Discretization of the flexible elements of cam mechanism is carried out by means of finite-element method. Furthermore, the dynamic model of the rigid-flexible coupled cam mechanism is proposed based on modal synthesis technique and Kane’s equations. The dynamic equation obtained is more general for flexible beam type, and very convenient for solving by computer because it is a modal-coordinates dynamic equation. The system dynamic performance is studied by analyzing the system modal and solving the dynamic equation. The simulation of dynamics model which has different orders is carried on, which can not only ensure accuracy of calculation but also save computational resources. Research results have important guiding significance for determining whether the dynamic analysis of high-speed cam systems in practical application is required, and furthermore, research results can provide strong guide for dynamic modeling and modal characteristics research of similar mechanism.
  • LIU Xinjun,XIE Fugui,WANG Jinsong
    Journal of Mechanical Engineering. 2015, 51(13): 2-12. https://doi.org/10.3901/JME.2015.13.002
    For the past two years, robots comeback with a high profile and present huge market prospects; advanced manufacturing equipment especially high-end CNC machine tool is still in urgent demand. However, their development is still not going well due to that basic components and CNC systems rely on imported goods, manufacturing techniques of key functional units are missing, reliability and performance of lead rails and lead screws are not good enough. In particular, swing tool heads and high-performance reducers, which greatly determine the functionality and performance of machine tools and robots, are important barriers for machine tools and robots in China to catch up with the world’s advanced level. Mechanism is a basic discipline of equipment structural design, and mechanism innovation is fundamental to the equipment innovation. Then, mechanism is naturally charged with the responsibility of innovation. Incorporating with the structure, functionality and application of machine tools and robots, the opportunities encountered by mechanism in the current stage of China have been analyzed and discussed. Hopefully, this work can provide references for the effective integration of academic research and industrial demand for advanced manufacturing equipment.
  • LU Chao, YANG Xuejuan, DAI Xiang, CHANG Junjie
    Journal of Mechanical Engineering. 2015, 51(6): 79-86. https://doi.org/10.3901/JME.2015.06.079
    Acoustical guided waves modal analysis in rail is the basis of long distance guided wave inspection and rail vibration and noises control. In particular the various propagating guided waves in the rail are identified in terms of their propagation wavenumber coefficients and their corresponding deformed shapes. The semi-analytical finite element method is used to formulate the governing equation for guided waves propagating in elastic waveguides of arbitrary cross-section on the basis of the virtual work principle, wavenumber dispersion curves and deformed shapes are extracted by solving governing equation, which provide the basis for selecting mode and frequency during application. The propagating guided waves wavenumber dispersion curves and deformed shaped under 0-8 kHz frequency range for CHN60 type free rail are obtained using semi-analytical finite element method, and the characteristics of the eight based guided waves mode in rail are discussed. Instrumented hammer experimental study and modal analysis using sever vibration accelerometers mounted on rail are carried out to verify the vertically vibrating mode and horizontally vibrating mode guided waves wavenumber dispersion coefficient. Modeling and experimental investigations of lateral and vertical excitation in railhead shows that good agreement between numerical calculation and experiment.
  • NI Ziqiang,WANG Tianmiao,LIU Da
    Journal of Mechanical Engineering. 2015, 51(13): 45-52. https://doi.org/10.3901/JME.2015.13.045
    Robotics in medical have made giant strides in past several decades with its widely use in various aspects. According to it’s function and usage, medical robots are classified into 7 types: neurosurgery robot, orthopedics robot, laparoscopic robot, vascular interventional robot, prosthetics and exoskeleton robot, assistive and rehabilitation robot and capsule robot. The functions, specifications, advantages and disadvantages of present typical commercially available medical robotics are surveyed. The current research foci, key technology and future trends of medical robotics are also discussed.
  • LI Wei, YUAN Xinan, CHEN Guoming, GE Jiuhao, JIANG Yongsheng, JIA Tingliang
    Journal of Mechanical Engineering. 2015, 51(12): 8-15. https://doi.org/10.3901/JME.2015.12.008
    Drill pipe is a critical and vulnerable component in oil & gas industry. A novel feed-through alternating current field measurement (ACFM) is proposed to achieve in-service detection for axial cracks on the surface of drill pipe. The finite element model is built by ANSYS software for analyzing the induced electromagnetic field distribution and disturbance caused by the axial crack on the external surface of drill pipe. Signal features of the crack are extracted through quantitatively analyzing the relationship between the size of crack and disturbance field. On the basis of theory and FEM simulation, the feed-through ACFM system is set up and proved by the axial crack of drill pipe detection experiments. The results show that, the signal features of Bx and Bz from the feed-through ACFM system show the depth and length information of the axial crack respectively on pipe string, and the lift-off effect can meet the demands of in-service detection for drill pipe. Furthermore, the feed-through ACFM system with sensors array can detect all the axial cracks in-service with a single pass scanning.
  • BAI Jia, LIU Ming
    Physical Testing and Chemical Analysis Part A:Physical Testing. 2020, 56(2): 44-47,54. https://doi.org/10.11973/lhjy-wl202002011
    The platen superheater tube of a domestic flame boiler burst and leaked after one month operation. The burst causes of superheater tube were analyzed by means of macroscopic examination, chemical composition analysis, hardness test, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that long-time over temperature operation caused tube burst. Weld beadings inside the girth weld of superheater tube joint blocked the steam flow, and oxide skin impacted heat transfer, which caused partial wall overheating for a long time. Serious aging of microstructure and obvious creep damage of burst mouth reduced the strength of tube material, and the pressure bearing capacity of tube wall and finally led to burst and leakage of superheater tube.
  • YU Jingjun,HAO Guangbo,CHEN Guimin,BI Shusheng
    Journal of Mechanical Engineering. 2015, 51(13): 53-68. https://doi.org/10.3901/JME.2015.13.053
    Since the concept of compliant mechanisms (CMs) is firstly proposed in late 1980s, it develops rapidly and has become an important branch of modern mechanism community. In the past less than 30 years, dozens of design methodologies and theories for CMs have emerged, which lays a solid foundation on their successful use. With the increasing insight for flexures and CMs, more and more applications of CMs can be found in various fields. After summarizing and comparing the current design methods for flexure-based compliant mechanisms five years ago, the state-of-arts of CMs have been overviewed from the point of application in this paper. Most existing CMs are resorted to three categories, i.e. precision engineering, bionic robotics, and smart structures if considering the difference of their functions and application background. The successful uses, study focuses and even application prospects in each category of CMs are introduced case by case. Afterward, four new types of CMs with great potential applications, i.e. cellular CMs, contact aid CMs, lamina emergent mechanisms, and static balance CMs are illustrated in brief. We hope more scholars all over the world start to study these amazing CMs and industrial personnel pay more attention on the usage of CMs as well after getting the overview of CMs.
  • ZENG Ming, YANG Yu, ZHENG Jinde, CHENG Junsheng
    Journal of Mechanical Engineering. 2015, 51(3): 95-103. https://doi.org/10.3901/JME.2015.03.095
    In order to extract machinery fault characteristics that are submerged in strong background noise, a general singular value decomposition (SVD) based subspace noise reduction algorithm is applied to signal processing, i.e., μ-SVD based denoising method. It can be proved that the traditional SVD based denoising method is a special case of the μ-SVD based one where μ=0. μ-SVD based denoising method contains a filter factor that plays a role in restraining information contributions of the noise-domain singular values to the denoised signal. μ-SVD based denoising method involves five parameters, including delay time, embedding dimension, noise reduction order, noise power and Lagrange multiplier. The selection methods for these parameters are discussed. In particular, the effects of noise reduction order and Lagrange multiplier on denoising performance are also studied. The experimental results of simulation signal with local fault and vibration signal with early crack fault in gear demonstrate that the μ-SVD based denoising method is superior to the traditional one in denoising performance, and can more effectively extract the gear fault characteristics at the presence of strong background noise.
  • DIAO Ruipeng,MENG Qingfeng,FAN Hong
    Journal of Mechanical Engineering. 2015, 51(4): 1-7. https://doi.org/10.3901/JME.2015.04.001
    The major parameter estimation error source for discrete Fourier transform are spectrum leakage and picket fence effect. A weighted two points vector interpolation algorithm based on Rife-Vincent window for improving the estimation accuracy of parameters for the multi-frequency damped signals is presented, where the signals are weighted by M-order cosine window family before the discrete Fourier transform and the equations with nuknown of frequency deviation and decay factor is established by the ration of two adjacent spectral lines near the real frequency position. The frequencies, amplitudes and phases are calculated by the frequency deviation solved from the above equation. The cosine window family with the characteristic of maximum sidelobe decay can essentially remove the spectral leakage and two point vector interpolation will cope with the problem of the picket fence. To combine the merits of the above two method can effectively increase the accuracy. The simulation and test results show that the proposed algorithm has a higher estimate accuracy and steady estimates. The higher computational efficiency and lower memory demand are suggested especially for poor computing resource situations. It also can be used as an optional method for the features extraction of the multi-frequency damped signals.
  • HONG Huangjie, WANG Hongyan, LI Jianyang, RUI Qiang, ZHANG Fang
    Journal of Mechanical Engineering. 2015, 51(4): 148-154. https://doi.org/10.3901/JME.2015.04.148
    Based on thermodynamics theory and finite element method, a finite element model of equipment and its airbag cushion system is established and verified experimentally. The simulation results are obtained under the same conditions of the airdrop test and the simulation results agree very well with the experimental results, which indicate the established model is valid for further research. Because nonlinear model of airbags cushion system is very complicated, the calculation takes tens of hours of CPU time. As a result, the large-scale calculation is impossible. In order to overcome this problem, surrogate models are employed instead of the complex finite element model based on extended latin hypercube method and radial basis function. Initial velocity, initial heeling angle, initial pitch angle, lateral velocity and gradient are variables, while maximum acceleration, maximum heeling angle, maximum pitch angle and maximum airbag pressure are responses. Considering the influence of landing condition, Monte Carlo method and surrogate model are used to calculate landing success probability of airdropping equipment under multi-condition. The landing success probability calculated is 95.84%. Acceleration is the primary contributor to cushion performance, while pressure inside airbag is secondary contributor.
  • WU Zijun,HUANG Zhengdong,ZUO Bingquan,LIU Qinghua,YIN Xiaoliang
    Journal of Mechanical Engineering. 2015, 51(5): 114-129. https://doi.org/10.3901/JME.2015.05.114
    Isogeometric analysis (IGA) is a novel numerical method for solving equations of physical fields, which is motivated by improving the integration between numerical simulations of physical phenomena and the computer-aided design tools, and provides a new way to associate product design with analysis and optimization via a common mathematical platform. The method of geometric modeling and its mathematical description are introduced in detail based on the computational framework of IGA. Taking NURBS as an example, the parametric representation in an analysis model and the mesh refinement method are analyzed, and the discretization methods, boundary conditions and quadrature in the parametric domain of IGA are discussed as well by comparing them with those in the standard finite element analysis. Applications of IGA in thermal analysis, fluid-structure interaction, contact problems and structural optimization are summarized and a simple example of 2D problem is provided.
  • LIU Yanjie,WU Mingyue,WANG Gang,CAI Hegao
    Journal of Mechanical Engineering. 2015, 51(1): 1-9. https://doi.org/10.3901/JME.2015.01.001
    A method for structural optimization design of wafer handling robot is presented. The static deformation of the end effector is employed as the constraint of the method. The nature frequencies of the rigid links flexible joints system are selected as the optimization objectives, and the thicknesses of the arms are determined as the optimization parameters. The dynamic model of the rigid links and flexible joints is established, and the modal analysis is carried out to determine the orders of the modal which will influence the trajectory precision. The masses of the second arm and the third arm are selected as the optimization parameters by the sensitive analysis of the nature frequencies. The deflection model of the arm is established with the variables of the thicknesses of the arm. The relationships between the thicknesses and the deformation of the end effector are analysed, and the structures of the arms are optimized based on the analysis. The comparison between the performance before optimization and the performance after optimization are carried out, and the result shows that the nature frequencies and the frequency of the vertical vibration are significantly enhanced and the deflection of the end effector is obviously reduced.
  • LI Zhibo, HUANG Qiangxian, SHI Kedi, HAN Bin, YU Huijuan
    Journal of Mechanical Engineering. 2015, 51(2): 1-6. https://doi.org/10.3901/JME.2015.02.001
    Recently, micro-nano coordinating measuring machine(CMM) has become a research focus in the field of three-dimensional(3D) micro-nano measurement. Due to the difficulty of the development of a 3D nano probe, a novel 3D resonant trigger probe has been proposed. This probe can reach nanometer/sub-nanometer resolution in three-dimensions, and its operation principle is different from the present contact probes and optical non-contact probes. The 3D nano resonant trigger probe is constructed by a piece of piezo-electrical PVDF film, two piezo-actuators, an integrated fiber micro-stem and micro-ball tip. The PVDF film vibrates at its resonant frequency and acts as a sensor. Using the piezoelectric property of PVDF film and the high sensitivity of its resonant parameters to the micro-force, the probe can give 3D trigger signal. The probe contacts the sample in traditional tapping-mode in z direction and friction-mode in both x and y directions. Experimental results show that the trigger resolution of 3D resonant trigger positioning system constructed by the above probe, 3D nano positioning unit, the feedback control module and the signal processing circuit could reach sub-nanometer resolution, which is 0.12 nm in x direction and 0.10 nm in y direction, while 0.12 nm in z direction. The 3D repeatability error is 26 nm, 36 nm and 10 nm respectively. The results demonstrate the validity of the new type of 3D nano resonant trigger probe and positioning system.
  • YAN Yan, LIU Yi, ZHU Junzhen, MIAO Ling, CHEN Xiaotian, ZHOU Yu, LU Yanping, GAO Bin, TIAN Guiyun
    Journal of Mechanical Engineering. 2021, 57(18): 75-85. https://doi.org/10.3901/JME.2021.18.075
    The long-term pressure and impact load brought by the interaction between wheels and tracks would cause Rolling Contact Fatigue (RCF) cracks on the rail surface and sub-surface. RCF cracks usually propagate along the surface of the rail and the direction perpendicular to the rolling surface of the rail. Conventional Non-destructive Testing (NDT) methods are difficult to quantify the three-dimensional shape and size of cracks. To overcome this challenge, a novel RCF crack quantification method is proposed, which utilizes skewness feature extracted from the RCF crack area's thermal videos. To validate the proposed method, multiple specimens with real RCF cracks have been prepared, and the location, direction, and depth of individual RCF cracks have been obtained through industrial Computer Tomography (CT) scanning for comparison. According to experimental results, the crack angle on the rail surface represented by the skewness is linearly related to the results obtained by CT, and the correlation coefficient is about 0.97. The correlation coefficient between the spatial propagation angle of cracks inside the rail calculated by the skewness and that in the CT is approximately 0.85. The correlation coefficient between the closed crack length value of the rail represented by the skewness and the results of CT is about 0.94. The skewness value has an approximately linear relationship with the corresponding crack depth, and the correlation coefficient reaches 0.98. The above results show that the proposed method can effectively realize the quantitative evaluation of RCF cracks. It also indicates that ECPT has broad application prospects in early diagnosis, quantitative evaluation, visualization, and in-situ inspection of RCF cracks.
  • DING Wenjun,SONG Baowei,MAO Zhaoyong,ZHAO Xiaozhe
    Journal of Mechanical Engineering. 2015, 51(2): 141-147. https://doi.org/10.3901/JME.2015.02.141
    To achieve long operation time for the detection device on the detecting unmanned underwater vehicle (UUV) in shallow water, a wave energy conversion system is proposed. This can harvest wave energy and convert to electrical energy near water surface. The principle structure and the design parameters of the permanent generator are described in detail. The mathematical model of the system is established according to Lagrange Equation. The influence on the power performance is investigated over a range of sea state by solving the simplified equation of motion using the Runge-Kutta method. Research results show that the proposed wave energy conversion system is reasonable and feasible, which can satisfy the energy demand of the detection device under general sea state. And the results also show that the parameters of the amplitude, the period and the coupling motion of roll have a high impact, the impaction of coupling motion of heave can be negligible. The research results will provide a theoretical basis for the engineering test of the wave energy conversion system.
  • LI Yan, LIU Hongwei, LI Mengdie, YUAN Ping
    Journal of Mechanical Engineering. 2017, 53(15): 1-20. https://doi.org/10.3901/JME.2017.15.001
    Design and innovation are the dominant themes of current times. Innovation is not the equivalent of technological invention, and it focuses on creating value by design, during the whole process of delivering technologies to users. Design thinking is the thought pattern to implement this process, and it is a way of innovation with considerable influence, high efficiency, and wild applicability. Design thinking can be broadly extended and integrated to every level as well as every field of the society. Therefore, any person or group can create new ideas efficiently by design thinking, and then make these ideas tangible as well as effective. Currently, the domestic and international scholars have carried out intensive research on design thinking and its related dimensions. This article systematically reviews the advances of research from the connotation of design thinking, implementation process of design thinking, methods and tools for design thinking, and research methods for design thinking. Finally, some existing issues and suggestions for further research are also summarized.
  • HE Genghuang, WU Mingyang, LI Lingxiang, ZOU Lingli, CHENG Cheng
    Journal of Mechanical Engineering. 2018, 54(17): 133-141. https://doi.org/10.3901/JME.2018.17.133
    In the view of denaturation mechanism and its influence factors of machined surface of titanium alloy, firstly, the action mechanism of cutting edge on the cutting area during cutting process is analyzed. The energy method is used to establish the model of structure parameters, three factors of cutting and cutting energy consumption. The model is solved combined with Matlab. The influence of feed rate f on the cutting energy consumption W of titanium alloy is the biggest, cutting speed vc is the second, and the influence of cutting depth ap is the least. In order to verify the validity of the model, two kinds of different type of cemented carbide index-able inserts are used to conduct the contrast experiments of titanium alloy TC1, TC4, TA5 and alloy steel 30CrMnSiA under the conditions of normal air cooling and argon cooling. Meanwhile, the denaturation mechanism of machined surface of titanium alloy is defined as well as the regularity of the development. The research results can offer data support for the high quality processing of titanium alloy.
  • YUAN Shuai, XIA Qinxiang, LONG Jinchuan, XIAO Gangfeng
    Journal of Mechanical Engineering. 2023, 59(14): 54-63. https://doi.org/10.3901/JME.2023.14.054
    The texture of magnesium alloys is easily formed during plastic deformation, and the influence of thermal deformation and inner ribs structure on the texture of cylindrical parts with inner ribs is complicated. The deformation field information during hot power spinning was obtained through macro forming simulation, and the texture evolution model was constructed by interpolation algorithm and macro-meso coupled method, the texture evolution of magnesium alloy cylindrical parts with inner ribs during hot power was investigated, and the differences of deformation texture of spun workpiece between cylindrical wall and inner rib were discussed. The results show that the sheet texture of blank will gradually change to the basal fiber texture of spun workpiece. The c-axis of grains will be deflected from the tangential direction parallel to the tube blank to the radial direction parallel to the spun workpiece, and the deflection angle of the grains at cylindrical wall is larger than that at inner rib. The deflection angle of position of the maximum texture strength and the maximum polar density in the polar diagram are used as evaluation indexes for model reliability analysis. The relative errors between the predicted value and the experimental value at cylindrical wall and inner rib are less than 10%, which indicates that the macro-meso coupled model can accurately predict the transformation of texture type and strength.
  • DING Wenfeng, MIAO Qing, LI Benkai, XU Jiuhua
    Journal of Mechanical Engineering. 2019, 55(1): 189-215. https://doi.org/10.3901/JME.2019.01.189
    Grinding plays the critical role in manufacturing the aero-engine components composed of nickel-based superalloys. In order to further improve the material removal rate and workpiece quality, a large number of researches on grinding technology of nickel-based superalloys are conducted in terms of the fundamental theory and process expending. In this review article, the basic principle and development process of grinding are firstly introduced briefly. Then, the technologies are reviewed detailed concerning the material removal mechanism, the grinding characteristics, and the novel application type of grinding for nickel-based superalloys. Finally, the development trends during grinding of nickel-based superalloys are proposed as well as the difficulties in grinding of such materials.
  • LEI Yaguo,JIA Feng,ZHOU Xin,LIN Jing
    Journal of Mechanical Engineering. 2015, 51(21): 49-56. https://doi.org/10.3901/JME.2015.21.049

    Mechanical equipment in modern industries becomes more automatic, precise and efficient. To fully inspect its health conditions,condition monitoring systems are used to collect real-time data from the equipment, and massive data are acquired after the long-time operation, which promotes machinery health monitoring to enter the age of big data. Mechanical big data has the properties of large-volume, diversity and high-velocity. Effectively mining characteristics from such data and accurately identifying the machinery health conditions with advanced theories become new issues in machinery health monitoring. To harness the properties of mechanical big data and the advantages of deep learning theory, a health monitoring and fault diagnosis method for machinery is proposed. In the proposed method, deep neural networks with deep architectures are established to adaptively mine available fault characteristics and automatically identify machinery health conditions. Correspondingly, the proposed method overcomes two deficiencies of the traditional intelligent diagnosis methods: (1) the features are manually extracted relying on much prior knowledge about signal processing techniques and diagnostic expertise; (2) the used models have shallow architectures, limiting their capability in fault diagnosis issues. The proposed method is validated using datasets of multi-stage gear transmission systems, which contain massive data involving different health conditions under various operating conditions. The results show that the proposed method is able to not only adaptively mine available fault characteristics from the data, but also obtain higher identification accuracy than the existing methods.

  • JIA Kang, ZHENG Shuai, GUO Junkang, HONG Jun
    Journal of Mechanical Engineering. 2019, 55(1): 216-224. https://doi.org/10.3901/JME.2019.01.216
    Focusing on the skiving of general internal and external profiles, a universal cutting edge calculation method, which involving the enveloping for discrete profiles, is proposed based on the working principle and the generating motion of skiving, and it suits for universal rake flank type. Meanwhile, the calculation method for contact points and corresponding spatial contact motion model are developed. Firstly, the skiving principle is analyzed, and the kinematic model is built in the terms of cutter, workpiece, and configuration parameters. Then, the forward and inverse questions of skiving are analyzed based on the conjugate theory, and the cutting edge curve identification that according to enveloping the intersection curves between rake flank and discrete workpiece surfaces is developed. Moreover, the detail schematic and calculation methods are described, and the judgment for the feasibility of the cutting edge is also given. Additionally, the ascertaining of cutting contact points by cutting edge and the approach on corresponded spatial cutting contact motions simulation are depicted. At last, examples for both external and internal skiving are given to verify the effectiveness of cutting edge identification and skiving motion simulation method.
  • Article
    JIN Bo;LIN Longxian
    Chinese Journal of Mechanical Engineering. 2014, 50(19): 1-8.
    To achieve non-destructive fruit and vegetable picking, an end-actuator with a simpler and more versatile structure is designed based on underactuated principle. The underactuated mechanism refers to machine that has fewer drivers compared with the number of degrees of freedom. The robotic hand designed by adopting the underactuated principle is simpler and more reliable. Due to simple structure and better adaptability to shape of objects, the robotic hand can fold the object completely with its fingers. Non-destructive harvesting is achieved by using a closed-loop force-feedback control algorithm which controls the maximum contact forces. Based on this design idea, a three-finger gripper which is driven by only one motor is designed. Through theoretical analysis, mechanism design and modeling, and structural optimization, the final model size is determined and physical production is completed. A control circuit combined with force-feedback control is designed for grasping experiments. The experimental results show that the robotic hand can achieve the desired grasping function, maximum contact force control and has such features as simple and reliable control, stable grasping and non-damaging.
  • PEI Hong, HU Changhua, SI Xiaosheng, ZHANG Jianxun, PANG Zhenan, ZHANG Peng
    Journal of Mechanical Engineering. 2019, 55(8): 1-13. https://doi.org/10.3901/JME.2019.08.001
    With the development of science and technology as well as the advancement of production technology, contemporary equipment is increasingly developing towards large-scale, complex, automated and intelligent direction. In order to ensure the safety and reliability of equipment, the remaining useful life (RUL) prediction technology has received widespread attention and been widely used. Traditional statistical data-driven methods are obviously influenced by the choice of models. Machine learning has powerful data processing ability, and does not need exact physical models and prior knowledge of experts. Therefore, machine learning has a broad application prospect in the field of RUL prediction. In view of this, the RUL prediction methods based on machine learning are analyzed and expounded in detail. According to the depth of machine learning model structure, it is divided into shallow machine learning methods and deep learning methods. At the same time, the development branches and research status of each method are sorted out, and the corresponding advantages and disadvantages are summarized. Finally, the future research directions of RUL prediction methods based on machine learning are discussed.
  • WANG Guobiao,CHEN Diansheng,CHEN Kewei,ZHANG Ziqiang
    Journal of Mechanical Engineering. 2015, 51(13): 27-44. https://doi.org/10.3901/JME.2015.13.027
    Bionic robots are good performance mechanical and electrical systems which imitate biological structures and motion characteristics of organisms according to the principles of bionics. They have shown their potential use in the dangerous conditions to human beings, such as anti-terrorism, space exploration and rescue. The bionic robots can be divided into three types according to their work conditions, such as the land bionic robots, the air bionic robots, and the underwater bionic robots. The developments of the bionic robots have experienced three stages, such as original exploration, imitation of the biological prototypes’ appearances and motions, mechanical and electrical systems with partial biological properties. The research status at home and abroad of these three types robots is discussed. And several problems of the researches are found after analysis, such as the lack of the biological motion mechanism researches, the traditional construction, material, driving and controlling mode, and the low efficiency of the power, leading to the difference between robots and creatures. These problems make the bionic robots similar in shape to the creatures but very different in essence. So the bionic robots now days are absence of effective applications. The development trend is pointed out that the bionic robots are developing towards lifelike system, including moving toward the rigid-flexible mechanism, integration of the bionics construction, material and driver, neuron fine control, and the efficient power transformation.
  • ZHANG Jinhua, WANG Tao, HONG Jun, WANG Yu
    Journal of Mechanical Engineering. 2017, 53(13): 19-28. https://doi.org/10.3901/JME.2017.13.019

    Soft-bodied manipulators are new type of mechanical devices mainly made of soft materials,which possess the characteristics of high flexibility,good adaptation in complex environment and safe human-machine interaction because of the flexibility and passive adaptability of soft materials. The soft-bodied manipulators have been intensively studied and shown great potential applications. The review of existing soft-bodied manipulators in terms of applications,actuation methods,materials and fabrication,modeling and control is presented. The current issues and possible solutions are also discussed. Soft-bodied manipulators are an important branch of soft robotics,which involves a combination of material science,mechanics,chemistry,mechanical design and manufacture,electronic and control science and biology. The study of soft-bodied manipulators will greatly enrich people’s understanding of the complex and rich characteristics of soft materials,and will provide theoretical and technical guidance for integrating soft materials into design of products.

  • SHE Chengqi, ZHANG Zhaosheng, LIU Peng, SUN Fengchun
    Journal of Mechanical Engineering. 2019, 55(20): 3-16. https://doi.org/10.3901/JME.2019.20.003
    New energy vehicle(NEV) has been widely used around the world in response to the fossil energy crisis and environmental pollution problems. NEV will generate massive real-world data during its daily operating which is contributed by high electrification and intelligent networking. Applying these multi-source heterogeneous data for a security warning and technical analysis will play a key role in promoting the development of NEV industry in China. The current situation of data-driven analysis technology in the NEV field is reviewed. Firstly, the basic theory of big data analysis techniques are introduced and the development of big data technology is depicted. The structure and function of the National Monitoring and Management Platform for New Energy Vehicles are introduced, and the particular process of big data analysis on NEV is emphasized. The previous data-driven research and methods in power battery, NEV daily operation and charging behavior are proposed for discussion respectively. Some representative research results and applications are displayed at the same time. Finally, the issues and prospects of the data-driven method on NEV application field are summarized and forecasted.
  • ZHENG Feifei, DONG Zhigang, ZHANG Jiatong, LIU Jinting, KANG Renke
    Journal of Mechanical Engineering. 2019, 55(1): 225-232. https://doi.org/10.3901/JME.2019.01.225
    Ultrasonic assisted grinding (UAG) shows great advantages on the machining of hard and brittle materials. To enhance the application of UAG, it is important to investigate its basic mechanism. A single diamond tool is used to conduct ultrasonic assisted scratching (UAS) tests for the purpose of imitating the material removal behavior of a single grain on the grinding wheel. The nominal and tangential scratching forces are compared under different ultrasonic amplitudes. The topographical characteristics are analyzed, including the width, depth and cross section area of the scratched grooves. The influence of ultrasonic vibration on the material removal behavior is discussed based on the scratching force, topographical characteristics and tool wear. It is observed that the scratching force significantly descended while the material removal significantly ascended with the help of ultrasonic vibration. The high-frequency impact and the intermittent energy input are considered the cause of observed UAS features.
  • YUAN Songmei, TANG Zhixiang, WU Qi, SONG Heng
    Journal of Mechanical Engineering. 2019, 55(1): 139-148. https://doi.org/10.3901/JME.2019.01.139
    The application of longitudinal torsional ultrasonic vibration machining in carbon fiber composite material and other hard brittle materials on more attention. Aiming at the problem that the torsional vibration amplitude is small and the coupling of longitudinal and torsional vibration is poor of the longitudinal-torsional ultrasonic transducers, a new longitudinal-torsional ultrasonic transducer is designed. An exponential type longitudinal vibration ultrasonic transducer with variable cross section is designed by theoretical analysis, then designed helical grooves in the exponential section to make a portion of longitudinal vibration convert to torsional vibration. The influence of structural parameters of helical groove on longitudinal and torsional resonance is analyzed by FEM, so the optimum helical groove parameters are optimized. The modal analysis and transient analysis of the transducer are carried out, the results show that the transducer can realize longitudinal vibration and torsional vibration, and the deviation was small for the resonance frequency between design value with simulation value, and the simulation amplitude value meets the general processing requirements. Finally, impedance analysis and amplitude test of the designed transducer are carried out, the results show that the resonance frequency is smaller than the simulation value, the longitudinal vibration amplitude is 9.4 μm, and the torsional vibration amplitude is 5.3 μm, which can be applied to most ultrasonic machining, and the correctness of the design method is also verified.
  • Du Qungui;Sun Zhiquan;Huang Chongxi;Zhai Xiaochen
    China Mechanical Engineering. 2016, 27(08): 1053-1058.
    Impact of pneumatic cylinder at the stroke terminal was considered to be an integrated system of vibrations, including slender piston rod, mass load, piston and end cover.Based on one-dimensional wave equation, a mathematical model of longitudinal   vibration of slender piston rod was established firstly. Impact force,contact displacement and  contact time were analyzed by means of mode superposition method.Then impact process of pneumatic cylinder was numerically simulated by nonlinear FEM software LS-DYNA.The variation of impact interface force and contact time were studied in detail under different masses of driven load and impact velocities. Compared with numerical solution of LS-DYNA,the accuracy of analytical solution was verified, and how impact force varies as velocity and load was concluded. Vibration frequencies of impact response were furtherly analyzed, and reasons for the changes of impact forces were studied. Research conclusions provide reference for design and applications of pneumatic cylinders.
  • SUN Zhenyu, WANG Zhenpo, LIU Peng, ZHANG Zhaosheng, CHEN Yong, QU Changhui
    Journal of Mechanical Engineering. 2021, 57(14): 87-104. https://doi.org/10.3901/JME.2021.14.087
    To achieve significant fuel consumption and carbon emission reductions, new energy vehicles have become a transport development trend throughout the world. However, new energy vehicle safety issues are increasingly prominent with the increase of new energy vehicle, which seriously threatens the life and property of drivers, and restricts the development of new energy vehicles industry. According to statistics, 60% of fire accidents in new energy vehicles are caused by power batteries. The development of advanced fault diagnosis technology for power battery system has become a hot spot in the field of safety protection. In order to fill the gap in the latest Chinese review, the faults of power battery system are classified into internal faults and external faults based on the difference of fault location, and the failure mechanisms of over-charge, over-discharge, external short circuit, internal short circuit, sensor fault, connector fault and cooling system fault are described. From the perspectives of internal faults and external faults, the research status and latest progress of three types of fault diagnosis methods are summarized including knowledge-based, model-based and data driven for lithium-ion power batteries. The main problems in the current research and future development on power battery fault diagnosis technology are discussed. In this way, accurate diagnosis and early prevention of power battery system faults can be realized, the life and property safety of drivers can be guaranteed, and the safety and the further development of the new energy vehicle can be promoted.
  • Review
    Guo Yong, Lai Guang
    Journal of Mechanical Transmission. 2020, 44(2): 154-165. https://doi.org/10.16578/j.issn.1004.2539.2020.02.024
    With the development of robotics technology,industrial robots are widely used in automation production,which greatly improves the production efficiency and automation degree. Trajectory planning is the key link to complete the task,and trajectory optimization further improves the quality of mission completion and meets the needs of industrial development. The research progress of trajectory planning and optimization for joint space of industrial robots is reviewed. Firstly,the algorithm of joint space trajectory planning is briefly described. It is pointed out that polynomial interpolation is the main mode,and B-spline curve is an inevitable trend of future development due to its excellent characteristics. Then,the trajectory optimization under different objectives is comprehensively summarized,and the existing problems such as the determination of the optimization objectives and the improvement of the algorithm are pointed out. Finally,the future development direction is prospected. The multi-objective optimization solution and dynamic adjustment of constraints will be the focus of future research.
  • LIU Xiaomin, HUANG Shuiping, WANG Jianhui, LIN Guijie
    Journal of Mechanical Engineering. 2016, 52(23): 34-42. https://doi.org/10.3901/JME.2016.23.034

    The principle of analogy source design and functional analogy is introduced, and inspired by the connection between analogy design principle and TRIZ tools, the source design of function analogy process model based on TRIZ is established. Firstly, the relationship between user requirements and each function is obtained using function structure model. The related product function is endowed with the weight value of user requirements, and the functional similarity matrix constructed is standardized by Matlab tools. So the quantitative correlation between the source design and design problems is represented in the matrix. Finally, the process model of conceptual design based on TRIZ and function analogy is established. Functional similarity of the UV fume purifying machine and functional analogy source design is analyzed. Moreover, the obtained functional principle solution is evaluated by effective value analysis to validate the correctness of the model.

  • LEI Yaguo, JIA Feng, KONG Detong, LIN Jing, XING Saibo
    Journal of Mechanical Engineering. 2018, 54(5): 94-104. https://doi.org/10.3901/JME.2018.05.094
    Faults are a potential killer of large-scale mechanical equipment, such as wind power equipment, aircraft engines and high-end CNC machine. And fault diagnosis plays an irreplaceable role in ensuring the health operation of such equipment. Since the amount of the equipment diagnosed is great and the number of the sensors for the equipment is large, massive data are acquired by the high sampling frequency after the long-time operation of equipment. Such massive data promote fault diagnosis to enter the era of big data. And machinery intelligent fault diagnosis is a promising tool to deal with mechanical big data. In the big data era, new opportunities have been brought to intelligent fault diagnosis. For instance, data-centric academic thinking will become mainstream, it makes fault diagnosis in the system level possible, and a comprehensive analysis of faults becomes a trend. Meanwhile, new challenges have also been brought:the data are big but fragmentary, the fault feature extraction relies on much prior knowledge and diagnostics expertise, and the generalization ability of the shallow diagnosis model is weak. The characteristics of big data in intelligent fault diagnosis are discussed, and the inland and overseas research advances are reviewed from the three steps of intelligent fault diagnosis. The existing key problems of the current research in the era of big data are pointed out, and the approaches and research directions to these problems are discussed in the end.
  • HU Zhen, YANG Zhijun, BI Hui
    Machine Tool & Hydraulics. 2021, 49(15): 97-100.
    The component feed screw can complete the actions of increasing distance, reducing distance, diverging, merging, lifting, undulating, turning of regular or irregular batch packaging containers. Based on SolidWorks software, the steering screw design of complex bottle type was completed by using the principle of generating method. The operation process was modeled, and the screw design of the new bottle could be completed by directly modifying the corresponding model. Through the comparative analysis of the rotational acceleration curve, a suitable rotational curve was provided. At the same time, modeling error and transportation stability were analyzed.
  • ZHANG Wenjia,SHANG Weiwei
    Journal of Mechanical Engineering. 2016, 52(3): 1-8. https://doi.org/10.3901/JME.2016.03.001
    Suitable trajectory planning methods can improve the smoothness, rapidity and efficiency of motion control of robot. Polynomial and trigonometric formulation are often adopted to realize smooth trajectory planning for cable-driven parallel manipulator, while the two approaches are complex and have weak rapidity. A new combined planning method with S-trapezoid curve is proposed for the point-to-point motion of planar 2-DOF cable-driven parallel manipulator, and the unilateral constraints on cable tensions are computed according to the dynamic model. Considering the specific point-to-point trajectory includes a list of target points that must be reached in sequence, thus it can be divided into the initial segment, the middle segment and the final segment. And then the combined planning method with S-trapezoid curve is applied to plan the velocity curve of the three segments. The acceleration is zero at the initial and final point, while it’s nonzero at the middle points. The dynamic trajectory planning can be realized with this state. The proposed planning method is implemented on a 2-DOF cable-driven parallel manipulator, and the simulation results indicate that the unilateral constraints on cable tensions could be satisfied and the acceleration curve is simple first-order curve, thus high-speed point-to-point motion could be realized.
  • CAI Shibo, TAO Zhicheng, WAN Weiwei, YU Haoyong, BAO Guanjun
    Journal of Mechanical Engineering. 2021, 57(15): 1-14. https://doi.org/10.3901/JME.2021.15.001
    A multi-fingered dexterous hand is a highly flexible and complex end-effector for robots. Since it can imitate various dexterous grasping and complex manipulation abilities of human hand, multi-fingered dexterous hand has been continuously studied and developed for more than half a century and has attracted extensive attention and received wide expectation from the public. In this paper, the research and development of humanoid multi-fingered dexterous hands are reviewed and analyzed. The complexity of multi-fingered dexterous hand is analyzed from aspects of bionic structures, actuation systems, transmission, sensing, composite/smart materials, and modeling and control. The complexity of multi-fingered dexterous hand is discussed from an applicational viewpoint in three levels:Partial function repetition, agile manipulation imitation, and function enhancement of human ability. Simplified realization of the complex application based on multi-fingered dexterous hand is also discussed. The dialectical relationship between the complexity of multi-fingered dexterous hand and the simplicity of application is illustrated. Finally, the trend and challenges of the multi-fingered dexterous hand research are analyzed concerning bionics, flexible sensing technology, manipulation planning, control strategy, and reducing cost.
  • YE Qian
    CHINAESE HYDRAULIC & PNEUMATICS. 2016, 0(01): 1-5. https://doi.org/10.11832/j.issn.1000-4858.2016.01.001
    Aiming at the problems of the existing isothermal discharge method, such as big measurement error and poor repeatability, a deep research on the measurement errors of the isothermal discharge method has been conduced. The influences of the pressure gradient, the temperture gradient and the measurement noise on the results of the isothermal discharge method have been discussed, the research products are helpful for improving the performance of the isothermal chamber and reduce the measurement error of the isothermal discharge method for testing the flowrate characteristics of the pneumatic components.
  • ZHAO Bin, QUAN Long, HUANG Jiahai, CHENG Hang, LI Guang, ZHANG Yongming
    Journal of Mechanical Engineering. 2017, 53(6): 176-186. https://doi.org/10.3901/JME.2017.06.176

    Mining hydraulic shovel is one of widely used equipment in open-pit mining and large engineering construction. However, the shovels used in domestic are always dependent on importation. In 2008, Taiyuan Heavy industry started to research and development the first domestic mining hydraulic shovel whose weight is 260 t and capacity of the bucket is 15 m3. Swing motion is the most frequent movement of mining excavator and each operating cycle includes two times of acceleration and deceleration. If the swing circuit can’t be designed will, that will cause serious heating of system and impact the working efficiency of the machine. In order to shorten design period and comprehend the working performance before the construction of the real system, the advantages and disadvantages of open circuit and closed circuit are analyzed to determine the specifications and parameters of hydraulic components. The mechanical dynamic simulation software ADAMS and mechatronic system simulation software AMESim are used to build the co-simulation model of whole designed mining hydraulic shovel. During the working process of mining excavator, the operation performance and energy efficiency characteristic of the two circuit are simulated, a method that using electro hydraulic proportional controlled double closed circuits for swing control driven in parallel way is determined. An electro-hydraulic proportional pump is used to control the rotary motor directly, which can avoid the throttling loss of valve controlled system. Meanwhile, in order to simplify the circuit, the hydraulic shovel own pilot pump is used to realize the compensating of closed circuit.The influence of rotary inertia’s large range variety on the rotation characteristic is further simulated and researched, the relationship between the time acceleration and deceleration and swing angle. The whole electro-hydraulic swing system is designed and applied the designed mining hydraulic shovel. Field tests and trial run tests indicate that the designed electro hydraulic proportional controlled double swing closed circuits can smoothly control the upper car acceleration and deceleration under the condition of large range variety of rotary inertia, the heating is small and the shovel can work continuous for a long time.

  • LIU Yajun, ZI Bin, WANG Zhengyu, YOU Wei, ZHENG Lei
    Journal of Mechanical Engineering. 2022, 58(7): 53-74. https://doi.org/10.3901/JME.2022.07.053
    Spray painting as an important part of the modern product manufacturing process, not only plays a beautiful, protective, and other special role, but also increasingly become an important part of the product value. In the furniture, aerospace, military industry, and other fields occupy an important position. The intelligent spraying robot is a complex electromechanical system composed of computer, sensor, vision and intelligent control technology. As the core of intelligent spray-painting technology, the development of intelligent spraying robot is closely related to the application of new materials, new designs, and new methods. Aiming at the common problems of key technology research of intelligent spraying robot, the current research achievements are summarized from the aspects of the mechanism design of spraying robot, dynamic performance monitoring of spraying system, automatic planning of spraying trajectory, and spraying quality inspection. Then the challenges of robot mechanism design and flexible spraying system integration in the process of intelligent spraying system are analyzed and discussed. Finally, the future development direction of key technology research of intelligent spraying robot is prospected and summarized, which provides a reference for the development direction of spraying robot and the improvement of key technology performance, and promotes the overall intelligent spraying technology.
  • WEI Jing, ZHANG Aiqiang, QIN Datong, SHU Ruizhi
    Journal of Mechanical Engineering. 2017, 53(1): 1-12. https://doi.org/10.3901/JME.2017.01.001
    Aimed at the problems of lower calculation accuracy of lumped mass method and large-scale computing, difficult post processing of finite element model, a novel coupling vibration analysis method for multistage planetary gear system is presented. The various components in planetary gear system are divided into three shaft models, which are simple shaft unit, planet carrier shaft unit and ring gear shaft unit, according to the structure characteristics of planetary gear system. Different types coupling dynamics model are established for planetary gear system. The results indicate that, the dynamic meshing force deviations obtained by shafting element method are almost same as that by the lumped mass method under the circumstance of lower rotation speed. But the dynamic meshing force and the resonance frequencies are both slightly lower with the increasing of speed. For a same input speed, the dynamic meshing force deviation is increasing with the thickness of ring gear, but the change tendency of the quantity is gradually decreasing. In all flexible structures, flexible shaft has a largest influence and planet carrier has a minimal impact to the vibration of the system. The gear meshing frequency in multi-stage planetary gear system are coupled with each other and become the excitation frequency of the system, and the mesh frequency of high speed stage is main excitation frequency of system. The vibration energy of the system is not only transmitted along the power flow direction but also reverse the direction of power flow transmission.