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Table of Content

    10 October 2016, Volume 27 Issue 19
    Morphological Filtering Method for Vibration Signals of Hydraulic Pump under Sinusoidal Variable Load Conditions
    Liu Siyuan, Yang Mengxue, Wang Chuang, Zhang Wenwen
    2016, 27(19):  2557-2563. 
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    Vibration characteristics of the pump vibration signals would change when they suffered a significant variable loads, especially in the role of sinusoidal load changes, and would produce amplitude modulation phenomenon. The filtering effects of the traditional single-scale structure element morphological methods was not necessarily ideal to this kind of signals. Therefore, for vibration signal characteristics of sinusoidal load pump, on the basis of the single-scale morphological analysis, a multi-scale morphological filtering method was proposed, which took both of length and height scale of the morphological structure elements. Firstly, taking the impact feature ratio and second geometric moment as characteristic index, then, the optimization method of structural elements length scale and height scale was proposed, which determined the optimal length and height scale operator combination. Afterwards, filtering the sinusoidal load simulation signals and variable load hydraulic pump failure vibration signals using the optimal scale combination, the results confirm that the filtering effectiveness is better than that of single-scale filtering method.
    Study on Microscopic Contact Area in One-dimensional Fractal Interface of Interference Fits
    Shen Jian, Yi Lixiang, Zhou Dan, Liu Guangfu, Du Xiaodong
    2016, 27(19):  2564-2569. 
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    Through the analyses of the surface profile based on the simulation fit between impeller and shaft, one-dimensional roughness feature of machined surface was obtained. Surface profile of vertical machining direction had obvious fractal characteristics. A theoretical contact model containing one-dimensional roughness feature and fractal characteristic was established based on modified M-B fractal contact model. And the calculation formulation of the real contact area under different normal contact loads was given. Combined with practical rough surfaces, a solid model with one-dimensional roughness feature and fractal characteristic was built to simulate and analysed by ANSYS. The results verified the calculation formulation.
    Grinding Parameter Optimization of Face Gears
    Ming Xingzu, Luo Dan, Liu Jinhua, Yan Hongzhi
    2016, 27(19):  2569-2574. 
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    Based on the analyses of the grinding parameters of face gears, under the conditions of meeting product quality requirements and other design constrains, a multi-objective optimization mathematical model was established, which took grinding efficiency and surface quality as the objective function. The interior penalty function method and genetic algorithm were used to solve the multi-objective optimization model,and three groups of the best scheme of grinding conditions were obtained, that might make the grinding efficiency and surface quality be improved. Experiments were performed according to optimized results. The effectiveness and practicability of this method were validated by analyses and applications.
    Lightweight Structure Design and Optimization Method for a Light Mobile Manipulator
    Yang Shiqiang, Wang Beibei,
    2016, 27(19):  2575-2580,2588. 
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    A mobile manipulator was presented based on the original mobile robot. A light weight manipulator with 5-DOF was presented and its 3D solid model was constructed. The lightening schemes of the key parts were presented to reduce the whole weight of the manipulator and the structure was optimized. The rules of stress and strain to the key parts with different lightening schemes under different loads were provided by finite element method, and the modals and vibration modes of the key parts were obtained as well. The advantages and disadvantages among different lightening schemes were contrasted, and the best lightening scheme was given. The theoretical basis for the optimization of the manipulator structure design was shown.
     mobile manipulator; finite element analysis; structure optimization; lightening schemeA mobile manipulator was presented based on the original mobile robot. A light weight manipulator with 5-DOF was presented and its 3D solid model was constructed. The lightening schemes of the key parts were presented to reduce the whole weight of the manipulator and the structure was optimized. The rules of stress and strain to the key parts with different lightening schemes under different loads were provided by finite element method, and the modals and vibration modes of the key parts were obtained as well. The advantages and disadvantages among different lightening schemes were contrasted, and the best lightening scheme was given. The theoretical basis for the optimization of the manipulator structure design was shown.
    Research on a New Method for Screw Rotor Processing Using Abrasive  Water Jet
    He Xueming, Chen Zehua, Wu Meiping, Zhang Rong
    2016, 27(19):  2581-2588. 
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    In the traditional machining processes of screw rotors, there were problems such as tool wear and high cutting heat. Abrasive water jet machining had some characteristics of no tool wear, low cutting heat and environmental protection. An abrasive water jet was introduced into the research of screw rotor processing, and a new method of abrasive water jet was proposed to improve the machining accuracy and efficiency of the rotors. The arbitrary Lagrangian-Eulerian method was applied to construct the rotor machining simulation model, the accuracy of simulation model was verified by comparing the simulation results with the experimental data. Finally, through the analyses of the simulation results of multi axis machining of abrasive water jet, it is proved that the new machining method of screw rotors has certain rationality.
    Study on Electrochemical Mechanical Precision Finishing Technology
    Pang Guibing , Xu Wenji, Zhou Jinjin
    2016, 27(19):  2589-2593,2601. 
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    This paper summarized the research work progresses of authors in recent years, included: the combined machining technology where the shaping and finishing were realized in one process, the cross scale precision forming technology where the precision and roughness of parts might be improved at the same time and hand-held tool finishing technology for free curved surface parts by which the surface topography might be improved under the conditions of ensurence of the precision of parts. The study results indicate that, by optimizing the process system structure and parameters of electrochemical mechanical machining, the accuracy and surface topography may be improved for those parts with regular surface like gears and bearings etc, and surface topography may be improved on conditions that the precision is guaranteed for those parts with irregular surfaces.
    Active Light Stereo Target Detection and Its Applications in Industrial Robot's Pose Measurement
    Zhang Xu, Zheng Zelong
    2016, 27(19):  2594-2601. 
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    A visual method with an active light target was proposed to obtain the positions and orientations of robots herein. First, the active light stereo target adopted active infrared light instead of reflective markers and employed shape features instead of brightness features to encode the location informations. Second, the stereo structure was designed to provide the spatial geometric constraint information. The active light target owned five feature planes to expand the visibility no mater what pose. Third, a detection method of feature planes was proposed. The proposed feature detection method was testified under different situations, such as indoor illumination environments, the direct solar radiation at outdoor square and the mixed illumination environments. The experimental results confirmed the feasibility and reliability of the proposed method. Forth, the precision of the proposed visual method was verified in a high precision platform. The experimental results show the average position error is as 0.0857mm and the average orientation error is as 0.1086° in measuring distance ranging from 0.5~3m. Finally, the pose measurement of a YASKAWA robot arm, Motoman-MH80, was conducted and the experimental results confirmed the feasibility and efficiency of the proposed method.
    Impacts Wide Paver Screed Conveyor of Speed on Dosing Quality
    Jiang Wan, Zhu Zhendong
    2016, 27(19):  2602-2606. 
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    At present, due to the uneven distribution of feeding amount across the width from spiral distributor, the Chinese wide paver could not work continuously and resulted in paving with low efficiency. Considering the unevenness of distribution in the required width, this paper established the modeling and simulation, and proposed an approach which might reflect the influences of the screw shaft rotational speed on the feeding amount across the width by evaluating the mass flow of the cross sections. Meanwhile, the paper established the models of the paver's advancing speed, the scraper plate speed and the screw speed, and achieved the effective matching, so as to improve the dosing quality and the efficiency of paving.
    Online Monitoring of Shearer's Pick Wear Based on ANFIS Fuzzy Information Fusion
    Zhang Qiang, Wang Haijian, Li Liying, Liu Zhiheng
    2016, 27(19):  2607-2614. 
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    In order to realize the realtime and accurate online monitoring of the wear degree in the cutting processes, the vibration signals, acoustic emission signals and temperature signals of different wear degrees were tested and extracted, and the multi feature sample databases of different wear degrees to the cutting signals were established. The optimal fuzzy membership function for each characteristic signal was calculated by the minimum ambiguity optimization model, and the method of the ANFIS multidimensional fuzzy neural network was adopted to realize the fusion of multi sensor feature informations, then the fusion results of the output confidence and weight were higher. According to the results of the random experiments of the fusion system ,the identification degree of the cutting wear monitoring system based on ANFIS fuzzy information fusion is high, and the maximum error of the test results is less than 6.5%, and the results show that the system has good fusion effect and higher test accuracy.
    Semantics Modeling for 3D Tread Patterns-oriented
    Dong Yude, Song Zhonghui, Zhang Rongtuan, Bai Sucheng, Zhang Fangliang, Liu Yanchao
    2016, 27(19):  2614-2623. 
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    Aiming at fussy operations and expressions of design information scattered of 3D tread patterns modeling, which caused by the way that dominated by geometric features, a semantic-driven 3D modeling approach was proposed herein. The structures of the groove features, ornament features and intersection features in the theoretical design were decomposed abstractly  to obtain the semantic units of the tire pattern based on discussion and research on the application theory and practical technology of pattern design. Then,the hierarchical, systematic, formal expressions of tire tread pattern from conceptual design to assembly design were realized by the introduction to tire pitch information.Finally, feature-based modeling technology was introduced, making CATIA / CAA as the development platform to develop a semantic level 3D tire patterns design system. The example analysis results show that the system is applicable to a variety of types of tire patterns modeling, enhancing the ability of the CAD technology design of information description and improving the automation level of product modeling, thus effectively reducing the repetitive work of designers and shortening the development cycle.
    Path Sorting Optimization of Robotic End-effector by Improved ACA
    Zhang Tie, Su Jiewen
    2016, 27(19):  2624-2629. 
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    For the path sorting optimization of robotic end-effector in robotic machining , a solution was presented, that established mathematical model for this problem and converted it to generalized traveling salesman problem (GTSP) and solved this problem by ACA. Meanwhile, the classical ACA was improved with multi stage search strategy, neighborhood search strategy and multi ant type strategy, so that the improved ACA was able to calculate a more optimized end-effector path for robotic machining. The results of simulation and robotic machining prove that the end-effector path obtained by improved ACA is shorter than 3% above the basic ACA's.
    Synchronous Control of Dual-drive System in Gantry-type Machine Tools Based on Disturbance Observer
    Li Ping, Zhu Guoli, Gong Shihua, Yue Lan
    2016, 27(19):  2630-2636. 
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    According to the structure and motion characteristics of the double drive system in CNC gantry-type machine tools with moving beams, a mechanical coupling dynamic model of double drive system in the gantry-type machine tools was established based on Lagrange's equation. Combined with the dynamic model of transmission system and the three closed loop control structure of servo system, the double drive system model of gantry machine was obtained. In order to reduce the effects of asymmetric structure and eccentric load disturbance on the synchronization accuracy and improve the anti-interference of the system, a dual drive system synchronization control method was proposed based on DOB. Finally, the simulation analyses were carried on. The simulation results show that the synchronization performance of double drive system to improve in gantry-type machine tools is obviously improved after the disturbance compensation by disturbance observer.
    Technological Experiments of Ultrasonic Deep Rolling with Longitudinal-torsional Vibration
    Zheng Jianxin, Hou Yali
    2016, 27(19):  2636-2640. 
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    Q235 steel was processed by UDR with LTV(UDR-LTV) based on orthogonal tests. The effects of processing parameters on surface roughness and surface micro hardness were studied. The prediction models for surface roughness and micro hardness were constructed based on the experimental results. The experimental results show that UDR-LTV may lead to a marked reduction the surface roughness and a considerable increase in surface micro hardness. The values of surface roughness increase first and then decrease with the increment of the static pressure; and increase markedly with the increment of the feed-rate, and change a little with the increment of the rolling speed. Meanwhile, the feed-rate has a marked effect on the surface roughness. The values of surface micro hardness increase with the increment of the static pressure; and fluctuate a little with the increment of the feed-rate and the rolling speed. And the static pressure has a marked effect on the surface micro hardness. t-test and the coefficient of correlation were calculated. The calculated results indicate that the surface roughness are most affected by the interaction of the feed-rate and the static pressure, and the surface micro hardness are most affected by the interaction of the static pressure and the rolling speed. The optimal parameters for the lowest surface roughness and highest micro hardness obtained by the orthogonal test are close to that obtained by the prediction models, which indicates that the prediction models are reliable.
    Multi-objectiveDynamic Optimization of Gantry Crane Metal Structure Systems
    Yuan Yuan, Yang Zhengmao , Meng Wenjun
    2016, 27(19):  2641-2646. 
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    Focused on the complexity and highly nonlinearity of the structure dynamic characteristics in a gantry crane, considering the uncertainty of dimensional parameters and lifting loads in metal structure design of the gantry crane, a parametric finite element model and experimental design methods were used to establish the relations among the design variables and dynamic parameters of the gantry crane structure systems. The non-dominated sorting genetic algorithm (NSGA-Ⅱ) was used to find the layout optimization of the truss girder internode and their sizes, then the requirements of low-stress, high natural frequency and lightweight were met. On the basis of high-precision response surface approximation model, Monte-Carlo simulation technique was used to evaluate the robustness performance of the optimization program. The application results indicate that the dynamic structure optimization of the gantry crane may be effectively achieved, and the design quality and efficiency are evidently improved.
    Mechanics Analyses of Shearers Based on Resistance Tests
    Chen Hongyue, Zhang Kun, Yuan Zhi, Mao Jun,
    2016, 27(19):  2646-2651. 
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    To obtain the loads on the walking support unit of a shearer during the cutting processes, a 6-order model was established by applying the theories of the classical mechanics, and the disadvantages of the model were analyzed. Aiming at the over constrained problems caused by the 4 supporting points between the shearer and the scraper machine, the mechanics model for the entire shearer was proposed by using the deformation compatible equation. The loads on the left driving roller and the right driving roller were achieved by the experiments, and the loads were input into the model. The model was numerically solved by employing the successive discrimination method. The solving results show that the forces in Y direction on the left guiding boot and the left smooth boot are as smaller than that on the right sides, the axial forces on the two guiding boots are small but the directions of them are opposite. The solving results were validated by the experiments, and the results show that the model is effective.
    Research on Buffering Process of Electro-hydraulic Variable Valve Train
    Tu Bo, Tian Hua, Wei Haiqiao, Pan Mingzhang
    2016, 27(19):  2652-2658. 
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    The buffering of electro-hydraulic variable valve train might affect the impact properties and the response performance of the valve motions. Therefore, a electro-hydraulic variable valve train system was designed based on AMESim. Throttling area and throttling stroke of the throttle possessed effects on the buffering process of the valve motions. In addition, genetic algorithm was used to search for the optimization control parameters of throttle to improve buffering performance of the valve motions. It may be concluded that decreasing throttling stroke and increasing throttling area may improve the response performance of valve motions. The final speed of valve stroke may be greatly optimized by genetic algorithm, and may be reduced to 0.11m/s in valve opening process and 0.07m/s in valve closing process, as well as guarantee of the response performance of valve motions.
    Analyses of Processing Parameters of BGA Solder Joint Based on Yield of Self-assembly
    Chen Yilong, Jia Jianyuan, Fu Hongzhi, Zhu Zhaofei
    2016, 27(19):  2658-2662. 
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    The influences of the deviation rates of volume of the solder joints and diameters of pads on the yield of self-assembly were studied to improve the yield of BGA components. Considering the thermal warpage, the unavoidable deviations in the manufacture of the volume of solder joints and the randomness of the positions of solder joints, the processes of self-assembly were discussed. The stand-off curves of solder joints with different volumes were obtained according to solving the shapes of solder joints. Based on the stand-off curves of solder joints, the influences of the deviation rates of volumes of the solder joints and diameters of pads on the yield of self-assembly were simulated. The common range of the stand-off curves of solder joints and the yield are increasing with the decreasing of the deviation rates of volumes of the solder joints and diameters of pads.
    Design and Analysis of LEMs Planar Springs
    Liu Kai, Cao Yi, Ding Rui
    2016, 27(19):  2663-2667,2674. 
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    To avoid vibrations and abrasions caused by the rotation of a planar spring in the deformation processes, a new planar spring was proposed based on LEMs. The planar spring with advantages including a small volume, easy to fabricate, a simple structure and no revolution during the deformation, etc. might be fabricated from planar materials and might emerge out of the fabricated planar materials. Firstly, the stiffness of the planar spring was deduced based on the flexural cantilever model and the pseudo-rigid-body model respectively. In order to verify the correctness of the theoretical stiffness formulations, the ANSYS model for this planar spring was established and the FEA was compared with theoretical results calculated by the flexural cantilever model and the pseudo-rigid-body model, respectively. The results indicate that the formula derived from model of cantilever leads to the calculation with higher accuracy when the deformation is small. In contrary, the formula derived from pseudo-rigid-body model applying to large deformation is better. Finally, the applicable ranges for the two above mentioned models were analyzed separately and a numerical example was given to demonstrate their correctness.
    Bionic Investigation on Multiple Intersecting Egg-shaped Pressure Hulls
    Zhang Jian, Zuo Xinlong, Wang Weibo, Tang Wenxian
    2016, 27(19):  2668-2674. 
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    Bionic design of multiple intersecting egg-shaped pressure hulls was carried out based on goose egg shell. Firstly, egg-shaped function was established according to a series of biological experiments of egg shells. Then, multiple intersecting egg-shaped pressure hulls in deep sea were designed. Numerical models with 2, 3, 4, 5, 6 eggshells were established. Critical buckling loads, yield loads and buoyancy factors of these hulls were studied. Finally, effects of the main geometric parameters on the performances of the multiple intersecting egg-shaped pressure hulls were analyzed using orthogonal experimental design. The results show that Kitching function is the best egg-shaped function describing goose egg meridian. The length-to-eccentricity ratio is as 45, and the egg shape index is as 0.69. The critical buckling loads of the egg-shaped pressure hulls are larger than yield loads, indicating that strength is the main factor of the structural design. The number of eggshells has little influence on the yield loads and buoyancy factors, while the shell thickness has a great influence on them. The geometrical parameters of the rib have little influence on the buoyancy factors but great on the yield loads.
    Numerical Simulation and Analysis on Formation of Subsurface Damages of Optical Lenses
    Ren Zhiying, Gao Chenghui, Chen Weiping, Lin Youxi
    2016, 27(19):  2675-2681. 
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    In view of the current research on the subsurface damages of the optical lenses, people mainly focused on the process parameters and abrasive particle size, distribution, and et al. Based on the theory of indentation fracture of brittle materials, this paper analysed a series of processes which led to subsurface damages of the optical lens, and then finished the micro dynamic simulation of the polishing process of optical lens surfaces under the different sharpness angles of the grains,and with the same load and the different processing speeds. Finley, this paper obtained the frictional contact, the stress and strain distribution and subsurface damages between abrasive and the lens' surface. The relationship among the relevant parameters of the subsurface damage depth of crack, the subsurface damage depth, hole volume removal rate, surface damage rate, abrasive sharpness angle and grinding speed was summed up. When the grinding grain sharpness angle is as 54~58 degrees, the processing speed is as 7~8m/s, then with the required processing efficiency subsurface damages and the damage rate of the machined lenses are of the minimum.
    Driving Behavior Operation Pattern Modeling Method Based on Individual Characteristics
    Xiao Xianqiang, Yin Yanjie, Wang Jiaen
    2016, 27(19):  2681-2686,2692. 
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    In order to study the method of the driving behavior operation pattern modeling which might reflect the individual characteristics of driver, the driving operation data of drivers using the automobile driving simulator were collected and the raw data was preprocessed by means of Kalman filter. Then, a method of individual driving behavior operation modeling was put forward based on the directed digraphs by analyzing the operation data of drivers with a method of combining the data and mechanism. The method was tested with the data of overtaking behavior on mountain highway. The results show that the driving behavior operation pattern modeled with the method may effectively reflect the individual characteristics of drivers and may provide technical supports to solve the problems of the driving operation pattern modeling for the individual and intellectual driving safety assistance systems.
    Research on Power Adaptive Motor Used for City Overloading Electric Vehicles
    Guan Yuming, Wang Xirui, Yan Tang, Liu Qin, Liu Chenchen
    2016, 27(19):  2687-2692. 
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    To meet the requirements of the drive motor, which possessed the city overload electric vehicle of unique characteristics of driving, a new structure of power adaptive motor(PAM) was proposed. PAM inherited the characteristics of the permanent magnet DC motor, which possessed high starting torque, simple and reliable structure, easy control, and so on, and might satisfy the characteristics of the city overload electric vehicles, such as low speed, starting and breaking frequently, and large loading capacity. This paper took a 6/8kW prototype as an example and analysed the matching of the external characteristic curve and the city overload electric vehicles. Then the operating characteristics of the PAM were analysed from the entire rotate speed range. Finally, through the analyses and experimental validation, PAM as the city overload electric vehicle motor has certain advantages.
    MPPT Algorithms of AETEG Based on Dichotomy and Gradient Method
    Fang Wei, Quan Shuhai , Fang Hong , Tan Baohua, Huang Liang
    2016, 27(19):  2693-2697. 
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    A function of output power and voltage for thermoelectric conversion module was fitted by the least square method based on the AETEG experimental system. Herein, a novel MPPT algorithm characterized by the aggregated dichotomy and gradient method was proposed, in comparison to some traditional algorithms such as the open circuit voltage proportional coefficient method and the disturbance observation method et al. The experimental results show that the tracking accuracy and speed of proposed method are as 98.7% and 120ms respectively, having a significant improvements compared with existing algorithms.