Table of Content

25 May 2014, Volume 25 Issue 10

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Design and Simulation of Pneumatic Control Probe for Ultra-precision Asphere Measurement

Yin Shaohui, Peng Jiehong, Tang Kun, Chen Fengjun, Hu Tian

2014, 25(10):  1279-1285. 

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In the course of asphere contact-type measurement,the pneumatic control probe with aerostatic bearing was adopted to decrease the pressure where measuring probe acted on measured surface and the frictional force of the probe in the motion.A pneumatic control probe was designed herein for ultra-precision asphere measurement,the size of the square aerostatic bearing was calcuated by engineering algorithm,and three kinds of bearing model with different throttle orifices were established.At the same time,the finite element models for the internal air flow in the three bearing and the probe on the working status  were established respectively.The pressure distribution,pressure intensity and air flow rate of the above flow model were simulated by using Fluent fluid calculation software,and the probe static performance was also forecasted.The results show that the stiffness of the probe can reach 1.77MN/m,the magnitude of contact force between the probe and measured surface can be controlled in 0.1~7mN,the maximum consumed air flow can reach 3.6m3/h,and it meets the design requirements of the probe.

Study on High-speed High-precision NURBS Interpolator Based on Quantum Framework

Yu Daoyang, Han Jiang, Zhao Han

2014, 25(10):  1285-1289. 

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The paper studied the high-speed high-precision NURBS curve interpolation algorithm, put forward an embedded numerical control system based on quantum framework software bus structure, took NURBS curve high-speed high-precision interpolator active object as an example to research the active object construction method. Finally theoretical and algorithm correctness were verified through a period of rotor cycloid machining experiments.

Quantitative Measurement of Grit Distribution of Diamond Abrasive Tools

Su Lingling , Huang Hui, Xu Xipeng

2014, 25(10):  1290-1294. 

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This paper putted forward two parameters to evaluate the grit distribution quantitatively,which were as static grit density Cs and the distribution uniformity CV. The grit centroids were obtained from the binary picture processed from the SEM picture of the diamond tools. The static grits density Cs was obtained by counting the number of centroids. On the other hand, the area of every centroid was obtained through the Voronoi diagram approach. The distribution uniformity CV was defined as the coefficient of variation of the Gamma distribution of centroid area. Using the two parameters to  evaluate quantitatively the grit distribution for the same wheel surface and different grit distribution surfaces, the results show that the grit distribution morphology can be evaluated better with those parameters.

Hydraulic Roll-bending Flatness Control Based on Qualitative Reasoning of Cloud Model

Jia Chunyu, Bai Tao, Cui Fajun, Xu Shengjie

2014, 25(10):  1295-1298. 

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A cloud model combined the randomness of probability theory and fuzziness of fuzzy set theory, so the uncertain problems can be disposed better. This paper designed a two-dimensional cloud model controller of the hydraulic bending roll system, its control strategy needed no mathematical models of plant,the experience and logic decision qualitative expressed by linguistic value are transformed into the linguistic control rulers through linguistic atoms and cloud models, which can achieve flatness online control in real time. A hydraulic bending system of a company 1220 rolling mill was taken as the simulation object. Simulation results show that the cloud controller is simple and rapid, has good control performance, strong robustness,and a better control quality than that of the normal fuzzy controller.

Modeling and Experimental Analysis of Valve-control-cylinder System for Full-hydraulic Leveler

Zhang Huajun, Huang Qingxue

2014, 25(10):  1299-1303. 

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For a more accurate and more stable hydraulic servo system of the full-hydraulicleveler, from engineering reality that the spool control voltage was as an input signal and the cylinder displacement was as an output signal, a mathematical model was established herein based on high frequency response asymmetrical proportional servo valve controlling asymmetrical cylinder. The model was proved by simulation analysis and applications in the laboratory.

Analysis on Nonlinear Dynamics Characteristics of Continuum Iced Bundled Conductors

Liu Haiying, Zhang Qichang, Hao Shuying

2014, 25(10):  1303-1307. 

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Three-dimensional coupling continuum model of iced 4-bundle conductor was established based on modelling methods of flexible cable.A thorough analysis was conducted to determine the effects of structure parameters on every order modal linear nature frequency of the system,orbit diagrams and time-history curves of galloping system were presented through numerical simulation by means of the Mathematica program. The system belongs to vertical self-excited galloping mode according to stability criterion of dynamics  system, vibration frequencies departure from the same order linear nature frequencies, it shows that nonlinear factors make amplitude produce influences on frequency. Continuum model of iced conductor can reflect characteristics of the system by comparing with finite element.

Design and Applications of Rubber Shock Absorber in Airborne Photoelectric Pod

Liu Jiayan, Cheng Zhifeng, Wang Ping,

2014, 25(10):  1308-1312. 

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In order to protect the internal optical load of photoelectric pod,reduce vibration influences on airborne photoelectric pod's imaging quality and the stable accuracy, a rubber shock absorber was designed for the load of internal frame installation. Based on rubber damping principles, the shape of rubber shock absorber was designed and the parameters were calculated. An ultrathin rubber shock absorber was developed,and the optical load of internal frame was hoisted 1mm after fitting the rubber shock absorber. The results of the related experiments show that:the vibration intensity test value—root mean square acceleration is much less:from 23.1g fells to 10.0g in vertical direction, from 11.4g fells to 4.8g in horizontal direction, the vibration influences on the optical load are reduced effectively. The photoelectric pod mounted on aerial vehicle is applied, imaging quality is fine,tracking precision meets the technical specifications.

Real-Time Pose Estimation for Industrial Robot End Effector Based on UKF

Xiang Xiaojie, He Qingxi, Ying Zheng

2014, 25(10):  1312-1316. 

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To estimate the pose of industrial robot end effector quickly and accurately,a real-time estimation method was proposed based on UKF. This method was applied to industrial robot with laser feedback control system. In the industrial robot moving process, a rough estimation value of end effector pose was acquired by using forward position analysis and kinematics parameters of industrial robot in real time. And the position of a measured point fixed on end effector was obtained by a laser tracker. Then, UKF was employed to integrate the previous rough estimation value and the measured point position. The accurate pose of industrial robot end effector was evaluated by utilizing this method. Computer simulation results show that the presented method is achieved easily, and has fast calculation and high accuracy.

Reliability Evaluation of Complex Repairable System with Common Cause Failures

Ruan Yuanpeng, He Zhen, Zhang Xutao, Zhang Chi

2014, 25(10):  1317-1324. 

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Because of the drawbacks of traditional algorithms when dealing with the problems of evaluating the reliability and availability of complex repairable system containing components with propagated failures having selective effect, a Monte Carlo simulation algorithm was presented based on the idea of cellular automata. The proposed algorithm converted the system into a  two-terminal network, then, simulated the states of each arc of the network at different times based on basic assumptions of problems. The algorithm ascertained the connectivity of the network at different times in every iteration using cellular automata which had the advantages of parallel searching. The specific algorithms of computing reliability, instantaneous availability, interval availability, mean downtime and mean maintenance frequency per unit time of the system were proposed. Finally, an example was given to illustrate how the algorithms were applied.

Study on Quasi-circular Curve and Its Properties

Chen Ming, Liu Yanping

2014, 25(10):  1324-1332. 

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This paper studied the key design parameters, the eccentricity ratio e of eccentric circular curve and the eccentricity ε of elliptic curve, which were used commonly for non-circular gear transmission. By changing the pole of the polar coordinates, a new transformed elliptic curve named quasi-circular curve can be obtained, which can be regarded as generalized elliptic curve or generalized eccentric curve. Aiming at that the original elliptic curve and eccentric curve were just special cases of the quasi-circular curve, two key design parameters, eccentricity ratio e and eccentricity ε  were introduced into the mathematical expression of the quasi-circular curve to build a new expression of the pitch of  non-circular gear. The research indicates that the eccentricity ratio determines the minimum and the maximum radius of the quasi-circular curve and the eccentricity determines the shape of  the quasi-circular curve. The quasi-circular gear  transmission has the characteristics similar to the eccentric circular gears and elliptic gears, but it is more flexible and convenient to design.

Harmonic Analysis in Application of Hub Quality Classification Judgment

Yang Guang, Qin Yongzuo

2014, 25(10):  1333-1336. 

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The principles of harmonic analysis were introduced, the harmonic analysis was expounded in the application of automobile wheel hub quantity detection and classification decision. With the Fourier transform, calculating the harmonic amplitude and initial phase, and phase changed according to the particular step from 0°to 360°, the harmonic wave can be drew. With the Fourier transform, the discrete data were decomposed into periodic harmonic data, and it enhances the harmonic analysis testing hub quality intuitiveness.

Inspection of Cracks with a Laser-ultrasound/EMAT System

Mao Ying, Pei Cuixiang

2014, 25(10):  1337-1340,1368. 

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A non-contact ultrasonic testing system using a pulsed laser for ultrasound generation and an EMAT for ultrasound detection were developed for the inner crack inspection. To avoid the laser-induced ablation damage on the specimen, thermo-elastic model was used to excite ultrasound, the EMAT probe was used to receive signals. The EMAT in plane and EMAT out of plane were used to study the transversed wave and longitudinal wave spreading in the half aluminum test block respectively. Finally, combining the shadow method, the test system was used to measure the crack on the back of the specimen, the crack depth and the actual depth are very close. It is shown that, in the thermoelastic mode, the laser excitation, the method for EMAT probe received signals are feasible in the inspection of cracks.

Multi-sensor Information Fusion Fault Diagnosis Based on Improved Evidence Theory

Liu Xiliang, Chen Guiming, Li Fangxi, Zhang Qian

2014, 25(10):  1341-1345. 

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Aiming at conflict evidence resulting from uncertainty of sensor signals, a new multi-sensor information fusion fault diagnosis approach was proposed based on improved evidence theory. Firstly, a method to create original evidence was put forward using genetic neural network, where genetic algorithm was used to optimize neural network parameters so as to enhance the training speed. Secondly, vector space and direction similarity were defined and classification rule function was built to distinguish conflict evidence and similar evidence. Credibility modified conflict evidence to decrease the conflict effect from uncertainty. Finally, gear pump fault tests prove the validity of improved method, whose diagnosis precision is higher than that of single sensor diagnosis evidently. The threshold setup increases the flexibility and applicability.

Research on Wind Turbine Gearbox Fault Warning Method under Variable Working Conditions

Gu Yujiong, Song Lei, Xu Tianjin, Lei Qilong

2014, 25(10):  1346-1351,1405. 

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For the variable working conditions of wind turbine and difficulty in fault extraction and warning index quantization, a new wind turbine fault warning method was proposed based on k-neighbor anomaly detection. Firstly, non-stationary time-domain signals were converted to stationary or quasi-stationary angle-domain signals. Secondly, new dimensionless amplitude domain parameters were constructed and the early failure characteristics of order proportion sampling angle-domain signals were extracted. Finally, mapping the angle-domain series into multi-dimensional feature vectors, the potential abnormal information was excauated by means of k-neighbor anomaly detection, the early fault warning was realized. Finally,the paper verified  the effectiveness of the proposed method.

Rolling Bearing Fault Diagnosis Based on Laplacian Score and Fuzzy C-means Clustering

Ou Lu, Yu Dejie

2014, 25(10):  1352-1357. 

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According to the non-stationary features and fuzzy fault symptoms of the vibration signals of a rolling bearing with faults, a fault diagnosis method of rolling bearings was proposed using Laplacian score and FCM clustering. Firstly, the features of a vibration signal of a rolling bearing were extracted in time domain and frequency domain, from which an initial feature vector was formed. Then by using Laplacian score method to select feature, fault feature vectors were obtained. Finally, a FCM clustering method was used as a fault feature classifier to recognize different fault types of a rolling bearing. Application examples and contrast tests show that this method can be used to extract the features of vibration signals of rolling bearings and diagnoses the faults of rolling bearings effectively.

Online Indentification of Material Property Parameters of Pipes During Pressure Straightening Process

Song Xiaokang, Zhao Jun

2014, 25(10):  1357-1361. 

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According to the geometric particularity of longitudinally submerged arc welding(LSAW) pipes, at present a pressure straightening method inclined to be applied by the manufacturers to correct their straightness. Accurate identification of the material parameters of pipes is an important conditions for improving straightening precision of the material parameters which always have large fluctuations by the influences of the material batch, heat treatment and the deformation history. The equivalence relation between the small curvature pipe in pressure straightening process and the straight pipe in three-point bending process was verified by finite element method firstly. Then an on-line  identification system of the material parameters was establish based on the theoretical model of straight pipe in three-point bending. Finally, the material parameters of the pipes can be obtained by inputting the values of the pipes' geometric parameters, straightening moulds parameters and load-stroke experimental data to the system. The feasibility and the reliability of the identification system were verified by the FEM simulation of large pipes and the physical simulation experiments of small pipes.

Hydraulic System Failure Source Sequencing Method Based on Cleanliness Entropy

Zhang Genbao, Peng Lu, Liu Jian, Li Dongying,

2014, 25(10):  1362-1368. 

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Aiming at lack of quantification analysis methods and tools in the influences of hydraulic system cleanliness in the total system and the diverse problems of hydraulic system and the failure sources, the cleanliness and failures of hydraulic system were analyzed utilizing entropy weight method of information science for reference. The concept of cleanliness entropy was given for the first time and the hydraulic system influenced by cleanliness was analyzed. The characteristic judgment matrix of hydraulic system failure sources was built and the nonannihilative hydraulic system failures were dated back to the cleanliness of several components and oil. A mathematical model of cleanliness entropy was created and the expert marking was employed to evaluate and sequence different comprehensive cleanliness entropy weights and the key failure sources were extracted which affected the performance of the system. The paper utilized an example to calculate cleanliness entropy and a software simulation verified the calculation process of cleanliness entropy. At last, failure sources were of sequencing and the key failure sources were obtained. The method gives a reparation of the blind spot of the traditional analysis method of hydraulic system which is not able to quantify and improves the confirmation of the causes of hydraulic system failures to better directness and accuracy.

Experimental Study of Transient Response Capability on Traveling Wave Rotary Ultrasonic Motor

Zhou Jingliang, Chen Chao, Wang Junshan, Zheng Wei

2014, 25(10):  1369-1373,1380. 

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Aiming at transient characteristics and mechanism of traveling wave type rotary ultrasonic motor(TRUM) with inertia load, a dynamics model was derived, which could describe its response characteristics. From the power transmission mechanism point of view, response characteristics of the speed step of TRUM were analyzed. By means of transient characteristics experiments the effects of the step amplitude and inertia different loads on the step response time were evaluated. The experimental system for transient characteristics of TRUM was built, and the transient rotation speed response characteristics of TRUM with inertia loads were measured. The experimental results show that the transient response of TRUM can fulfill the requirements under special circumstances.

Engine Fault Classification Based on Characteristic Statistics of Vibration Signals in Angle Domain

Ding Yan, Shao Yimin

2014, 25(10):  1374-1380. 

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In order to improve the precision rate and success rate of engine fault classification, a new fault classification based on the characteristic statistics in angle domain was proposed. The new method used an optical encoder to acquire engine rotational vibration signals of equal angle sampling. Wavelet packet analysis and correlation coefficient method were applied to acquire the characteristic order of the engine signals in angle domain. Energy ratio, standard deviation ratio, spectrum energy ratio and spectrum mean ratio of the characteristic order were regarded as the characteristic statistics in angle domain to extract engine fault features. The method of support vector machines was also adopted to classify the engine faults. Experimental results using signals recorded from an engine with an improper fit clearance existed in the connecting rod bearing show, compared with the traditional fault classification, this new method can improve precision rate of the fault classification.

An Improved FCM Clustering Algorithm and Its Applications of Vehicle Driving Cycle Construction

Shi Qin, Ma Honglong, Ding Jianxun, Long Jiancheng, Ling Xiang

2014, 25(10):  1381-1387. 

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Since FCM clustering was relatively sensitive to the initial clustering center, iteration was inclined to fall into local extremum and the global optimum was difficult to obtain, a modified FCM method was presented to overcome the above defects. In order to get closer to the global optimal clustering, the data of the principal components were classified by a SOM network, and the obtained weights were used as the initial clustering center of the FCM clustering. The modified FCM clustering method was used for establishing driving cycle in Hefei city. The theoretical analysis and its corresponding results indicate that this method possesses a sound precison for establishing driving conditions, which can reflect the realistic urban traffic conditions comprehensively.

Decision Analysis in Reverse Supply Chain under Random Collection Quantity and Capacity Constraints

Cao Jian, Chen Ya, Zhang Xuemei

2014, 25(10):  1387-1394. 

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A two-echelon RSC system containing a manufacturer and a recycler was established with considering the factors of remanufacturing rate, collection effort and subsidies when facing the limitation of inventory capacity. For the two cases that the manufacturer or the recycler rented a facility, the optimal decision-making was analyzed under Stackelberg game and centralized decision in RSC. The relationships between the members' expected profits and various parameters as well as third-party facility were discussed by numerical simulations. The results indicate that the system benefit under centralized decision is optimal compared with Stackelberg game, and it can obtain better decisions as well as the system benefit when the manufacturer rents the facility instead of the recycler.

Nonlinear Explicit Dynamics Analysis of Sliding Friction-induced Vibration and Noise

Wang Dongwei, Mo Jiliang, Chen Guangxiong, Zhu Minhao

2014, 25(10):  1395-1399. 

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A numerical simulation was performed to study the sliding friction-induced vibrations and noises in a ball-on-flat configuration. The numerical simulation results were discussed with the experimental results, to investigate the mechanism of friction-induced vibrations and noises, and the dynamics characteristics of frictional contact surfaces when noise occurred. The results show that friction noise is caused mainly by self-excited vibration of friction system. The coupling of normal and tangential vibrations plays an important role in the occurrence of self-excited vibration and friction noise. The slave nodes are found to be not in continuous contact with the master surface when self-excited vibration occurs. The contact between slave nodes and master surface in a relative motion has a characteristic of stick-slip-separation-stick.

Research on Inner Porous Defect Control and Negative Tension Rolling Process of Large Section Bars

Huang Huagui, Wang Wei, Liu Yong, Du Fengshan

2014, 25(10):  1400-1405. 

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Aiming at a 150mm large section bar continuous rolling line, considering the porous defects in the large scale continuous casting billet as compressible material, a three-dimensional thermal-deformation coupled finite element model was established for heterogeneous large section bar rolling process with the rigid-plastic FEM. The influences of rolling tension on the porous compaction were investigated by numerical simulation. The simulation results show that the porous defects can be compacted better under negative tension rolling than that under zero tension and positive tension rolling. The spread and deformation are satisfactory in all the 9 passes, there is no defect appeared during the rolling process, and the final shape and dimension meet the requirements of bar production. The rolling force and torque was presented to evaluate the feasibility of this new rolling technology.

Similarity Analysis of Crankshaft NTR Upset-bending Physical Simulation System

Wang Dongyan, Zhang Lianhong, Li Hang

2014, 25(10):  1406-1409,1414. 

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The geometric,kinematics and dynamics similarity of crankshaft NTR upset-bending physical simulation system to the prototype system were studied. Based on the similarity theorem this simulation system met the geometric and the kinematics similarity conditions to the prototype system and when the relative coefficient α=0.05 they met the approximate dynamics similarity conditions. A NTR upset-bending experiment for one lead crankshaft billet was carried out on this physical simulation system, taking the 42CrMo steel 6G32 crankshaft as the prototype. The small crankshaft forming in this trial had sunks and flashes similar to the large forgings obtained in actual forming process. The dimension scale between the design size of the prototype and the main structure dimensions of the lead forging is as the same as the geometric similarity coefficient of two systems. The change of the force data recorded in the sensors in forming process is consistent with the expected trend.

Development Strategy of Frontal Crash Dummy Based on Chinese Human Body

Cao Libo, Huang Xingang, Dai Huangwei, Yan Lingbo

2014, 25(10):  1410-1414. 

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By using computer simulation method, the feasibility of developing a frontal crash dummy was studied, which was in accordance with the characteristics of Chinese human body through a few changes to the current Hybrid Ⅲ dummy. Based on the scaling method, the finite element(FE) model of dummy was developed which can fit the characteristics of 50th percentile Chinese human body. Since the limbs were the most different body parts between Chinese and American and the torso of dummy was difficult to process after scaling, thus only the sizes of limbs were scaled and the size of some parts of torso were adjusted to develop another FE dummy model. The third FE dummy model was developed by changing the parameters of materials of the standard dummy model. Frontal crash simulations were conducted by using these three dummy models. The results show that changing the parameters of material has little effect on dummy collision response but changing the dimensions of dummy has a great effect on it. It is also indicated that the dynamic responses of the partial scaled dummy are basically consistent with that of the full scaled dummy. Therefore, the partial scaling method can be used to develop the Chinese occupant dummy.

Research on Comprehensive Characteristics of an Electronic Gasoline Injector Based on MIM Technology

Cheng Qiang, Zhang Zhendong, Xie Nailiu, Guo Hui

2014, 25(10):  1415-1419. 

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In view of the problems such as unstable material property, low production efficiency, poor comprehensive performance of the products, MIM technology was introduced into the electronic gasoline injector's manufacturing process. According to the technical characteristics of MIM and performance requirements of the injector, a kind of Fe-based nano-crystalline soft magnetic alloy was used in the injector's specimen production. Comprehensive performances were compared between the samples obtained by MIM technology and the traditional products with the method of simulation and experiment. Results show that,the new samples have larger advantage than traditional products at aspects of the electromagnetic performance, the dynamic response characteristics and the dynamic flow characteristics.