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Table of Content

    25 May 2015, Volume 26 Issue 10
    Type Synthesis of a Novel Three Degree of Freedom Translational Decoupled Parallel Mechanism
    Zeng Daxing, Li Xiaofan, Qiu Xuesong, Chang Wei, Hou Yulei
    2015, 26(10):  1279-1283. 
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    Based on the screw theory, the realization conditions of the translational degree of  freedom(DOF) for the parallel mechanism were proposed, while the selective guideline of the input pair was elaborated and the configurations principles of the kinematic pair were established. All of these were to form the relatively complete type synthesis theory of the translational decoupled parallel mechanism(TDPM). According to the obtained theory, taking a practical engineering task as an example, a full isotropic  TDPM which was composed of three branches was achieved after synthesizing all branches of the 3-TDPM. Then the DOF and the forward and inverse solution of the new mechanism were analyzed. Finally, the prototype was manufactured in accordance with the configuration parameters which were obtained on the basis of the condition numbers of Jacobian matrix.

    Calculation Method of Spherical Plain Bearing Friction Temperature Field
    Yu Jianwei, Wang Lifei, Wei Wei
    2015, 26(10):  1284-1288. 
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    Taking thrust  spherical  plain  bearing  as the  research object,the  contact stress under axial load was analyzed and based on the experimental friction torque  the  dynamic friction coefficient was solved.Then combined with contact stress and friction  coefficient,heat  flow rate was calculated and served as  the second boundary condition  for  the  unsteady temperature field finite element analysis of the bearing.Finally,using  infrared  camera to shoot the outer surface of  two-dimensional temperature distribution  of the  bearing friction process,then reliability of  simulation results was tested.Simulation  and  experimental results show that: the calculation method has solved the problems of  accurate calculation of spherical friction coefficient and spatial distribution of the heat flow rate.Ignoring  the  spherical gap when modeling will  affect the contact stress distribution   directly and cause a larger error in temperature distribution.Considering a spherical gap  a more accurate bearing friction temperature  field can be  obtained.

    Study on Driving Control and Dynamic Behaviour of SMA Springs Array
    Ying Shenshun, Ji Shiming, Cai Donghai, Ai Qinglin
    2015, 26(10):  1289-1293,1300. 
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    This paper focused on control strategy and dynamic behaviour of a SMA springs array. The bionics structure of SMA springs array with 3 rows and 5 columns was firstly constructed, which was based on the analysis of biological microstructure of skeletal muscle. Then, an on-off control strategy for the SMA springs array was presented using mathematical statistical theory. The simulation results of the displacement and force characteristics of the array were provided based on ADAMS. Hardware control system and graphic use interface were developed, which was based on PLC and kingview software respectively. Scheme for control the activation of the SMA springs array was made, and the time histories of stretching force were got to understand influences of amount and location of the activated SMA springs. Experimental results indicate that there exists serious coupling phenomenon. Finally, the paper discussed the stretching force oscillation of the SMA spring array and its estimation method.

    Solution Methods for Carbonemissionsins of Group Welding Piece Manufacturing Process Based on Therblig
    Zhong Jun, Liu Zhifeng, Li Xinyu, Cheng Huanbo
    2015, 26(10):  1294-1300. 
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    Therbligs were incorporated to the carbonemission solution in the group welding piece manufacturing process. According to the associated properties among therbligs, the group welding piece manufacturing process could be divided into therblig with constant carbonemission velocity, and therblig with variety carbonemission velocity with process parameters. Therbligs were used for carrying out inventory analysis, and solution methods of carbonemission for group welding piece were proposed, and
     based on therblig the solution and analysis process could be proposed by cases.

    A Vibration Compensation Method Based on White-light Wavelength Scanning Interferometry
    Mao Jian, Xu Peng, Yang Jiangxin, Cao Yanlong
    2015, 26(10):  1301-1305. 
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    A  surface topography measurement system with vibration compensation was developed  herein  based on the white-light wavelength scanning interferometry.Both of  phase extraction algorithm and phase unwrapping algorithm was  analyzed for the white-light wavelength scanning interferometry.They could be used to modify the nonlinear errors during the acousto-optic tunable filter(AOTF) swept  at low rate.The hardware control module was designed for the vibration compensation.In order to verify the designed system,both of  3-dimensional(3D)  surface topography and the roughness parameter of the standard sample grinding at level 12 were  evaluated under different vibration environments.The results demonstrate that the measurement results  with low frequency vibration are  about two times than those of without vibration.After opening the system vibration feedback,the results  approache to the maximum allowed value.It shows that the proposed method can eliminate the vibration effect in a certain extent.Compared with two dimensional(2D) surface  evaluation  results,3D  surface evaluation can express the measured topography surface comprehensively.

    SVM Based on ACROA and Its Applications to Rotating Machinery Fault Diagnosis
    Luo Songrong, Cheng Junsheng, Hunglinh A O
    2015, 26(10):  1306-1312. 
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    Firstly, in view of SVM parameters optimization problem, combination to the advantage of ACROA, a new classification model, called ACROA_SVM was presented herein. Furthermore, the effectiveness and superiority of the ACROA_SVM model was identified via benchmark datasets, which was downed from the sit web of UCI. Lastly, combination to local mean decomposition and energy moment feature extraction, ACROA_SVM was served as approach of pattern recognition to identify rotating machinery fault types. The experimental results show ACROA_SVM method has higher precision, better generalization ability of fault diagnosis, and less time consumption, higher efficiency of fault diagnosis, which is conducive to realize online intelligent fault diagnosis.
     

    Effects of Gear Coupling on Aero-engine Vibration Characteristics
    Liao Zhongkun, Chen Guo, Wang Haifei
    2015, 26(10):  1312-1319. 
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    The aero-engine gear coupling stiffness was studied herein,and the coupling dynamic gearing forces were deduced, the relationship among the gear coupling gearing forces and the torque, misalignment,and the dynamic relative displacements was analyzed. According to aero-engine gearing structure characteristics,a rotor dynamic model including gear coupling and the three supports was established,and the effects of gear coupling stiffness on the system frequency response function were analyzed; under the conditions of considering the angle misalignment between two rotors, the effects of gear stiffness on the misalignment responses were studied. The results show that the dynamic gearing stiffness model can simulate the gear coupling dynamic stiffness very correctly, but the dynamic change range of the stiffness is not enough to change obviously the system dynamic characteristics, however, the effects of the angle stiffness of gear coupling on the system vibration characteristics are very great.

    Applications of a New Logic Intelligent Inference Method in Scheduling Optimization of Mixed Production Lines
    Wang Xianhong, Shi Guoquan
    2015, 26(10):  1320-1323. 
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    This paper presented the optimization of mixed production line with the features of multi work stations, simultaneous operation of the same work station with different efficiencies,having buffer area among work stations,and allowing waiting for work piece.This paper proposed a solution based on logic intelligent reasoning method and genetic algorithm to tactfully solve digital modeling and complex calculation issues for makespan.

    Component Optimization Design for Remanufacturing Based on Life Matching
    Song Shouxu, Feng Yan, Ke Qingdi, Liu Ming
    2015, 26(10):  1323-1329. 
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    Remanufacturing blanks were retired products and the component status was uncertain, the components could not achieve the best use. For the problem,this paper presented components optimization design for remanufacturing based on life  matching. Through the analyses of the existence of  “short board” effect in the product failure, the mean and multiple matching were established, and also the corresponding matching means. The design information model, performance feature model and their interaction and feedback model were presented. Finally, crank-bush life matching and the improvement of the initial design due to remanufacturing were carried out to verify the effectiveness and feasibility of the method.

    Algorithm of Manufacturing Demands and Resource Matching under Piece Production Model Based on Analytic Hierarchy Process(AHP)  and IFS
    Bi Keke, Niu Zhanwen, Zhao Nan, Peng Wei, Tong Kening
    2015, 26(10):  1330-1336,1344. 
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    Piece production model of large and complex equipment has the features as: vast amount of product specifications, complex and personalized structures, frequent changes of crafts, difficult process planning, long production lifetime, severe dependence on resources. Manufacturing companies could not predict the matching degree of customer demands and its own ability in the order stage. According to existing problems, this paper proposed the production demand and resource model based on part features, introduced the algorithm of featured process matrix and resource ability matrix matching based on AHP and IFS to calculate the matching degree. Finally the effectiveness of this method was verified using company examples. The results contribute to improve the quality of order evaluation in piece manufacturing company, to reduce the risk of orders and strengthen the competitiveness.

    Real-time Lane Recognition Method Based on Hardware-software Co-design
    Zhang Weiwei, Song Xiaolin, Zhang Sanlin, Wu Xuncheng
    2015, 26(10):  1337-1344. 
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    In order to obtain robustness and real timing for lane recognition, a lane recognition scheme was designed based on embedded system taking the effective allocation of hardware resource and software function into account. From the perspective of producer/consumer model of the whole system, the necessity of matched enhancement was put forward, and multi-scale matched filtering method was proposed according to the different width characteristics of lane markings, then an adaptive dynamic threshold was set based on local noise estimation from the improved mathematics model of CFAF. The road images of high frame rate and wide dynamic range were captured through field programmable gate array(FPGA) and then the matched filtering was speeded up through the coefficient decomposition technology in the hardware optimization design. Experiments and evaluation prove the proposed system can robustly detect lane markings under different traffic scenarios with the processing frame rate of 60fps.
     

    Finite Element Analysis on Turbocharger Turbine Box Based on Coupled Heat Transfer
    Gong Jinke, Tian Yinghua, Huang Zhangwei, Jia Guohai
    2015, 26(10):  1345-1350,1361. 
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    Based on the heat transfer mechanism of the turbocharger turbine box, a fluid mesh model and a solid one for simulation were  built by using the professional software CFD and FEM respectively. The multiple coordinate system of rotation in the fluid domain was established to calculate accurately the flow field of turbine boxes, heat transfer coefficient and temperature. Coupled heat transfer analysis of the turbocharger turbine box was carried out by the fluid-solid coupling method, and then the temperature field for solid areas was obtained. Based on the temperature,its thermal stress analysis was carried out. In comparison with the experiments, the temperature distribution of the simulation model accords with that of the realistic turbocharger turbine box, the maximum deviation is only 3.3%. The coupled heat transfer model for the turbocharger turbine box has a high accuracy, which provides the basis for better design of turbocharger turbine.

    Optimization of Extrusion Die of Spherical Plain Bearings Based on BP Neural Network and GA Algorithm
    Wu Lianping, Yang Xiaoxiang
    2015, 26(10):  1351-1355. 
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    The paper addressed a practical problem of the non-uniform clearance between the outer ring and the inner ring after the nosing process in the assembly of spherical plain bearings, the extrusion process of GEW12 spherical plain bearings was simulated by using ABAQUS software. BP neutral network was applied to identify the relationship between the die profile and the peak difference between the maximum clearance and minimum clearance. A genetic algorithm was used to optimize the die profile, which yielded more uniform clearance distribution. Thus, the FEM, neutral network, and genetic algorithm were combined to develop a method for the design of the optimal shape of a extrusion die. The experimental results show that the clearance distribution between outer ring and inner ring is improved greatly and the metal flow of the bearing becomes more uniform.

    A Model of Life Prediction for Fatigue-creep Interaction and Its Experimental Verification
    Chen Ling, Zhang Xianming, Ouyang Ping
    2015, 26(10):  1356-1361. 
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    Based on the ductility exhaustion theory and damage mechanics, the correlation  among the ductility consumption, damage, cycles and failure life of materials  under fatigue-creep interaction was analyzed  herein.And then, a model for fatigue-creep interaction life prediction was established.This model was very convenient for practical engineering applications  because of its simple formation.Through fatigue-creep interaction experiments with smooth specimens of  1.25Cr0.5Mo steel at 540℃ and 520℃ under stress control, which used a trapezium waveform with the hold-time per cycle, the prediction of the failure life was carried out by this model. Compared with the experimental data, it is found that the predicted results are  in good agreement with the experimental ones.Besides,this model can explain the life fluctuation under the same temperature and loading condition well.

    Transition  Interpolation  Algorithm for Micro-line  Segments  Based  on  Curve through Control Points
    Wu Ting, Zhang Libing, Huang Fengli
    2015, 26(10):  1362-1367. 
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    In order to reduce the velocity fluctuations and realize smoothing transition for machining of micro line segments, an interpolation algorithm was presented based on curve though control points. The curve transition vector model of micro-line segments was constructed. On the basis of geometric characteristics of curve model based on the characteristic polygon vertex, a vector model was proposed based on curve transition through control points. Interpolation of micro-line segments were  calculated by using vector model based on the curve transition according to the machining errors and geometric characteristics of the curve, values of control vertex were calculated, the constraint velocity was determined, and real-time look-ahead control  was processed. The proposed method was evaluated by an experiment, and experimental results demonstrate that the algorithm can effectively improve transition speed of the micro-line segments, shorten the machining time, and achieve smooth transition.

    Electrochemical Machining Analysis of Aero-engine Blade Based on Isogeometric Method
    Wan Neng, Du Ke, Gao Jingyu, Chen Tao
    2015, 26(10):  1368-1373. 
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    For solving the low precision problem for sensitive boundary which caused by traditional numerical analysis method, this paper proposed a method of promoting the analysis precision by using the isogeometric analysis. The NURBS basis functions were used to replace the Lagrange basis function for establishing the solving equations of the electrochemical machining gap. The problem of the non-interpolation feature belonged to the NURBS basis functions was settled, which could bring the errors for imposing  Dirichlet  boundary condition. At last, the superiority,including precision and the rate of convergence, of the isogeometric analysis was proved by the comparison tests.

    Effects of Diamond Abrasive Arraying Forms on Interdigitated Micro-channel
    Li Gang, Yang Qinghua, Wen Donghui, Lu Congda
    2015, 26(10):  1374-1380. 
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    Effects of diamond abrasive arraying forms on the interdigitated micro-channel were studied according to the design of micro-channel structure. Uniformity of lapping trajectory for fixed lapping was simulated, and fractal dimension of micro-channel was calculated with different abrasive arraying forms, both of macro and micro opening rate of bipolar plate surface were studied. Optimal spiral arraying form of diamond abrasive was obtained by comparing uniformity of lapping trajectory, fractal dimension and opening rate.

    Cross-organizational Resources Chain Monitoring Based on Time Series Prediction
    Wang Zhengcheng, Xian Da
    2015, 26(10):  1380-1384. 
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    This paper established time, cost, service capability, credibility integrated optimal monitoring model and the improved particle swarm algorithm was used to optimize parameters of support vector machine,the monitoring model was predicted by time series prediction.When the actual and predicted values of the model error ranges satisfied monitoring requirements, the resource service was normal. Finally, through an example, using the root mean square error(RMSE) as prediction accuracy of evaluation model,the results and comparative analysis show that the method is effective and feasible.

    Fault Diagnosis of Rolling Bearings Based on RQA and GG Clustering
    Zhang Shuqing, Bao Hongyan, Li Pan, Li Xinxin, Jiang Wanlu
    2015, 26(10):  1385-1390. 
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    A fault diagnosis method of rolling bearings based on RQA and GG clustering was put forward. The parameters of the RQA which were able to characterize the degree of divergence of the signal-determinism and laminarity were used to consist the fault feature vector. Combined with the GG fuzzy clustering, it could achieve the fault pattern recognition of rolling bearings. The analyses of the actual fault data show that the method is able to identify different degrees of damage of rolling bearing faults and to complete different parts of the bearing fault diagnosis. It provides an efficient and intuitionistic new way for the identification of rolling bearing faults.

    Development of AS-UCM Temper Mill and Its Shape Control Technology
    Bai Zhenhua, Chang Jinliang, Guo Qianyong, , Liu Yaxing, Feng Bin,
    2015, 26(10):  1390-1394. 
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    Because of ordinary UCM temper mill could not equip cooling means and had no choice to control asymmetric complex higher-order wave shape, a new AS-UCM temper mill was made up, which equipt work roll asymmetric bending, middle roll asymmetric bending, middle roll upward and downward asymmetric movement. This paper quantitatively analyzed the ability of AS-UCM temper mill by controlling loading roll gap shape, then established a shape control model fit for AS-UCM temper mill. By comparing the ability of AS-UCM temper mill and ordinary UCM temper mill by controlling asymmetric complex higher-order  wave shape under same condition, it concludes that the ability of AS-UCM temper mill by controlling asymmetric complex higher-order wave shape is more useful than the ordinary UCM temper mill. The model provides helpful references for controlling temper mill complex higher-order wave shape.

    Effect of Temperature on Buckling-resistance of Thin Sheet Steel
    Liu Dihui, Lin Chengye
    2015, 26(10):  1395-1398. 
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    Thin sheet will be heated after a period of time's rapid continuous cold forming and its buckling-resistance will be influenced. In  order to investigate the consequence of temperature variation on the sheet's buckling-resistance, uniaxial tensile experiments and YBT at different temperatures were performed. The properties of thin sheet at 23℃, 75℃ and 150℃ were acquired respectively  and it is found that the elasticity modulus, yield stress and tangent modulus decrease when temperature rises. The finite element simulations of YBT at different temperatures were done with the property's parameters obtained, and a good agreement between   force-displacement curves of YBT and the simulations is found. The comparison of results of YBT and the finite element simulations indicates that thin sheet's buckling-resistance is susceptible to the changes of temperature and it goes through the change processes of rise and fall when temperature rises from room temperature to 150℃.

    Investigation on Preparation Process of Zr-based Bulk Metallic Glass Micro Bilayer Gear Based on Multilayer Silicon Mold
    Yang Fan, Shi Tielin, Liao Guanglan
    2015, 26(10):  1399-1402,1408. 
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    The preparation process of Zr-based bulk metallic glass micro bilayer gear was investigated, where the multilayer silicon mold was prepared according to the multilayer design pattern. The technologies of superplastic micro-forming, mold unloading, overlap cutting and quality analyzing were optimized. Then, the Zr41.2Ti13.8Cu12.5 Ni10Be22.5 gear with 3mm diameter was obtained by the self-design experimental platform,a big gear layer was with 0.05 module, 36 teeth and 150μm thickness, small gear layer was with 0.05 module, 32 teeth and 150μm thickness, the center axle hols was with 0.8mm diameter. The results show that the gear  has complete shape, high filling rate and good surface quality, while its material maintaines amorphous.

    Fractional-order Fuzzy Control Method for Vehicle  Nonlinear Active Suspension
    Gao Yuan, Fan Jianwen, Pan Shenghui, Li Shan, Kong Feng
    2015, 26(10):  1403-1408. 
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    A fractional-order fuzzy control method was presented for vehicle nonlinear active suspension. This new scheme used a fractional-order differential signal as one of the control inputs, and the fractional order was obtained based on the minimum criteria of the suspension system comprehensive performance index function. Simulation results demonstrate that under the driving cycles with various grade roads and vehicle speeds, comparing with the traditional integral-order fuzzy control method, the presented method has better control performances including further reducing body acceleration, suspension travel and tyre deflection, and can  improve the ride comfort and handling stability of vehicle effectively.

    Rapid Optimization for Beam Cross-sections of Automobile Body Based on P1N1 Plant Growth Algorithm
    Song Kai, Cui Xiao, Yang Jun
    2015, 26(10):  1409-1415. 
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    In order to optimize the beam cross-sections of car body quickly and effectively in the conceptual design phase, a fast optimization method was proposed based on P1N1 plant growth algorithm. This method combined a database of the automobile body key section, taking into account the body styling, the internal space, the basic performance and other aspects of the manufacturing process constraints. By extracting the node coordinates and the performance parameters of the cross-sections, the node coordinates of beam cross-sections were imported into P1N1 plant growth algorithm as design variables to optimize, thereby controlling the beam cross-sectional shape. Based on P1N1 plant growth algorithm, a mathematical model and corresponding program were established. An application has proved this method can realize rapid optimization of beam cross-
    sections of the automobile body efficiently.

    Power Distribution Strategy Optimization for Two-mode Electro-mechanical Transmission
    Zheng Hailiang, Xiang Changle, Han Lijin, Zhang Donghao
    2015, 26(10):  1415-1419. 
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    Based on Pontryagin's minimum principle, an optimal control theory was applied to derive a methodology for the power split algorithm of two-mode EMT system. Under the premise of sustaining the battery state of charge(SOC), the fuel consumption was used as the optimization objective function. Then, the optimal system working conditions were determined according to the optimization process and the mathematical model of the system. The simulation results show that the research of EMT control strategy has significant oil-saving effect. The control strategy is effective and provides the foundation for developing and optimizing the real-time control strategy.