bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Application of Fuzzy Controller
Authors: Zhang Wei , Li Xue Yong , Li Li , Lv Jing Qiao , Chen Yan Feng , Mao Xin Hua
Published: January 2011

The steam temperature of the boiler is one of the important parameters in the power plant, and it is necessary to keep the temperature at a steady range. For the traditional PID controller, which is suitable for the analysis and design of the linear system, is unfit for the control of the steam temperature of the boiler, since it’s a nonlinear system where exists large time delay. To address this kind of problem, we combine the traditional PID method with the fuzzy logic method to construct a compound fuzzy PI controller in order to improve the performances in both steady state and transient state of the classical PID controller when highly nonlinear processes and better control performances have been arrived at.
Trajectory Recognition and Navigation Control in the Mobile Robot
Authors: Yang Chun Hui , Wang Fu Dong
Published: January 2011

Fast and accurate acquisition of navigation information is the key and premise for robot guidance. In this paper, a robot trajectory guidance system composed of a camera, a Digital Signal Controller and mobile agency driven by stepper motors is given. First the JPEG (Joint Photographic Expert Group) image taken by camera is decoded and turns to correspond pixel image. By binarization process the image is then transformed to a binary image. A fast line extraction algorithm is presented based on Column Elementary Line Segment method. Furthermore the trajectory direction deviation parameters and distance deviation parameters are calculated. In this way the robot is controlled to follow the given track accurately in higher speed.
Development of a Mobile Robot Control System Using IC Tags
Authors: Kawarazaki Noriyuki , Umeda Seiichiro , Yoshidime Tadashi , Nishihara Kazue
Published: January 2011

This paper provides a mobile robot control system using IC tags. We developed a mobile robot control system that is composed of an omni-wheel typed mobile robot, IC tags and a PC. The IC tag is very useful sensor for navigation of robot. This mobile robot moves according to the motion data from the IC tags. The effectiveness of our system is demonstrated by several experimental results.
On-Line Monitoring of Run-to-Run Control Performance in a Discrete Microelectronics Manufacturing
Authors: Chen Liang
Published: January 2011

Semiconductor manufacturing is challenged by strategy development for ensuring the yield of defect-free products. In this paper, an on-line performance assessment strategy is proposed to evaluate the EWMA-based run-to-run (RtR) controllers in a discrete microelectronics fabrication. Expressions of minimum variance performance (MVP) and best achievable performance (BAP) are derived in a rigorous way. Technologies such as close loop identification and numerical optimization are employed in order to carry out on-line monitoring. Case studies of the chemical mechanical polishing (CMP) unit operation show the efficacy and the attractiveness the strategy.
Effect of Input Shaping on Actuator Effort of Inertial Plants
Authors: Dong Ming Xiao , Pang Bo , Liu Hui , Li Fan Bing
Published: January 2011

Most motion control systems are designed to satisfy the performance requirement in transient and frequency domain. The actuator effort of the control system is rarely considered during the design process. This paper investigates the effects of input shaping on actuator effort of PD combined with input shaping control for an inertial plant subject to four standard types of inputs. The actuator efforts of the control systems are described in general fomula. The acting regulation of PD controller parameters on the oscillatory frequency and damping ratio of actuator effort is investigated and the effect of input shapping on the magnitude of actuator effort is thoroughly analyzed. The research results show that PD feedback control enhanced with input shaping can effectively reduce actuator effort compared with PD control.
Design of Progressive Die Based on Component in UG Environment
Authors: Tan W.S. , Zhou Jian Zhong , Guo J. , Huang Shu , Wang Cheng Dong , Gao B. , Sheng J.
Published: January 2011

. Progressive dies are widely used for the mass production of sheet metal components due to the high productivity, high precision and low cost, but the design of progressive die is a complex and highly specialized procedure. In this paper, a design method of progressive die based on component was presented. Based on the technology of component object module, a number of key techniques in the design of progressive die design were addressed, the knowledge-based design frame system was developed, and the assembling model under UG environment was established. Finally, a practical design process for progressive die of complex panel was demonstrated, and the 3D integrated mould was realized.
A Novel Variable Step-Size LMS Harmonic Detecting Algorithm
Authors: Yang Jian Ning , Guan Jia Jun , Ning Yan Min , Gu Chuan
Published: January 2011

This paper proposed a novel adaptive algorithm applied to the harmonic detection that improves the power quality and suppressing grid harmonic. Considering the signal noise ratio (SNR) of the load current is low, the improved algorithm uses the coherent average estimation of the proportion of error signal in the total signal instead of system error to update the step-size, so the step-size only depends on the real system tracking error, and the steady state error is small when the system is close to stable. In addition, the algorithm adopts the time window action of mean estimation to control the influence of past signal on the present one, which produces a big step-size when the system changes. Compared with the fixed step-size least mean square (LMS) algorithm in a grid load current detected by matlab simulation, the improved algorithm has a faster convergence rate, a higher stability precision, and a better performance of anti-noise, the simulation shows the effectiveness of the method.
A New Control Strategy of Five-Phase Permanent-Magnet Motor Drives with a Third Harmonic Current Injection
Authors: Liu Guo Hai , Yan Li Hao , Zhang Duo , Zhao Wen Xiang
Published: January 2011

In this paper, a five-phase permanent-magnet (PM) brushless dc (BLDC) motor is investigated, which has almost trapezoidal back electromotive force(EMF) due to its concentrated windings. Since the third harmonic component in the magnetic field is utilized, the presented five-phase BLDC motors have a higher torque density over conventional three-phase ones, in which the third harmonic current is injected. This paper proposes a new five-phase transformation system, by which the vector control is easily applicable to five-phase BLDC motors. Finally, the results verify the validity of the proposed method.
Kinematic Analysis and Simulation on Parallel Vibration Reduction Seat
Authors: Yang Qi Zhi , Huang Guo Quan , Long Chen , Zhu Xiao Bing
Published: January 2011

Vibration of vehicle system is a typical vibration of multi-degree freedom. The damping performance of multi-degree freedom seat suspension is important to ride comfort of vehicle occupants. Based on the multi-dimensional movement principle of parallel mechanism, it is built a new vehicle seat with 3-DOF suspension. It is Established a kinematics model and then analyzed the theory of the displacement of the parallel vehicle seat system. Finally, using ADAMS software to build the simulation models of seat suspension, it is showed that the seat vibration system has a good effort on vibration reduction.
Synthesis and Investigation on the Mechanical Properties of the Polypyrrole Film Doped with P-Toluene Solfonate
Authors: Pu Hua Sheng , Ding Jian Ning , Cheng Guang Gui , Ling Zhi Yong , Guo Li Qiang
Published: January 2011

In this paper, conducting polypyrrole (PPy) films doped with p-toluene solfonate (pTS) was electrochemically synthesized. The chemical groups of the sample were analysed by FT-IR, an in situ nanotribolab system together with the four-probe instrument were employed to investigate the mechanical and conductivity of the prepared films. The surface morphology was studied by scanning electron microscopy (SEM). It demonstrates that the dopant anion was doped into the PPy while the overoxidation did not occur during the polymerization. The conductivity of PPy film is stable, during indentation, different loads were applied and hardness, elastic modulus were obtained. SEM images showed that the film is uniform. The characteristic microstructure of polypyrrole, the cauliflower-like, is appeared and the film is compact and homogeneous.
A Robust Color Pseudo-Random Coded Structured Light Technique for the Recognition of 3D Object
Authors: Xu Zhen Ying , Xu Ran Ran , Cao Dan Dan , Wang Yun
Published: January 2011

A new robust structured light technique based on multi-valued pseudo-random color encoded pattern is discussed in this paper. After analyzing the advantages and disadvantages of the existing pseudo-random coding patterns in computer vision, a new multi-valued pseudo-random color encoded pattern is designed on the basis of the combination of the feature points and the feature lines. Using this pattern, the feature points are easy to extract, and the problems of leaking points and pseudo-feature points are greatly reduced. Furthermore, it also reduced the difficulty and the complexity of the feature matching because of the feature lines.
Spectral Detector Design for Nitrogen and Moisture of Rape
Authors: Xiang Zhi Yong , Li Bo Quan , Mao Han Ping , Zhang Xiao Dong
Published: January 2011

For the four spectral bands of rape canopy leaf which is sensitive to nitrogen and moisture contents, a reflection spectral detector was designed to measure nitrogen and moisture of rape, constituted by the adjustable light, filter module, passive detection array, signal conditioning and acquisition modules. Further, a test was carried on to verify performance by several different reflectivity of the plates and four levels of nitrogen and moisture rape. The result shows that correlation coefficient between the contents of nitrogen, moisture and output of detector was 0.78, relative error of the detector was 9.5%, accuracy of sample classification was 65%.
Research of Tower Crane Fleet Wireless Communication System Performance Experiment Based on ZigBee Module
Authors: Zheng Xi Jian , Liu Ming Da , Xie Zheng Yi
Published: January 2011

This paper deals with solution to building tower crane fleet wireless communication system. Feasibility of a system based on ZigBee module is analyzed. By researching transmitting mechanism of ZigBee module and analyzing interference factors during the transmission period,experiments are designed to test data transmission and anti-interference performance, on the condition of simulating on-site environment. Experiment results show that the wireless communication system based on ZigBee module is feasible and the data transmission is reliable.
Nonlinear Dynamics of a Parametrically Excited Laminated Beam: Deterministic Excitation
Authors: Lan Xiang Jun , Feng Zhi Hua , Lin Hong , Zhu Xiao Dong
Published: January 2011

The nonlinear dynamic equation of a laminated beam subject to parametrically deterministic excitation is derived based on the general von Karman-type equations and the Reddy third-order shear deformation plate theory. The first mode parametric resonance is taken into consideration using Galerkin approach. The modulation equations are obtained with the method of multiple scales. The frequency-amplitude and force-amplitude characters are investigated. Results show that the nonlinear behaviors belong to hardening effect.
Vibration Suppression of Yarns via Sliding-Mode Control
Authors: Lin Hong , Feng Zhi Hua , Lan Xiang Jun
Published: January 2011

In this paper, a dynamic model of yarn in sizing machines is proposed. The fluxion in moving speed is taken into consideration. By sliding-mode control, the transverse vibration control of the yarns is studied and the control law based on varied tensions is designed. Numerical simulation are carried out using the finite difference approach and results show that the convergence rate of spacing errors of the yarn is fast and the transverse vibration can be well reduced.
Control System Design for High Payload Industrial Robot via High Speed Communication Bus and Real-Time System
Authors: You Wei , Kong Min Xiu , Sun Li Ning , Guo Chan Chan
Published: January 2011

In this paper, aiming at solving the problems of dynamic coupling effects and flexibility of joints and links, a kind of control system specialized for high payload industrial robots is proposed . After the comparisons between the control systems in all kinds of robots and numerical machines, industrial PC with TwinCAT real-time system is chosen as the motion control unit, EtherCAT is used for command transmitting. The whole control system has a decoupled and centralized control structure. The proposed control system is applied in control of a kind of high payload material handling robots with complex compound control algorithms. The final results shows that the control commands can be easily calculated and transmitted in one sample unit. The proposed control scheme is meaningful to real engineering application.
Performance Prediction and Experimental Study of a New Electromagnetic Vibration Pump
Authors: Yuan Dan Qing , Zhang He , Wang Rui , He You Quan , Li Jian Ping
Published: January 2011

A new type of small flow and high head vibration pump with electromagnetic drive was designed for the production and daily life applications in north-western region of China, where people face the problem of water shortage. The power generated by electromagnetic actuator and the deformation produced by the elasticity board module were simulated using ANSYS software. The flow and head of the vibration pump were deduced and then the correlation between the pump characteristics and material and construction were analyzed. Experiments based on sample pump were carried out and the characteristics of the pump were obtained. The fact that the test results shows that simulation of the vibration of the pump based on ANSYS can effectively predict the performance of the vibration pump. The comparison of simulation value and experimental data indicates that this method is feasible and accurate. This research will provide references for further study of the vibration pump and adequate theoretical basis for industrial production.
Performance Analysis of Autonomous Obstacle Negotiating Robot in Unstructured Environment
Authors: Wang Cheng Jun , Ma Lv Zhong , He Tao
Published: January 2011

On the requirement of the obstacle negotiating robot in unstructured environment, a new type attitude-adjusting track mobile robot adapting to unstructured environment has been presented. This paper introduced the structure of the autonomous obstacle negotiating robot, the robot motion characteristics under typical terrain, and the side tumbling attitude-adjusting and automatic reset. This kind of mobile robot has the characteristics of simple structure and practical operation and has strong ability of environment adaption and obstacle negotiating walking.
Interior Permanent-Magnet Synchronous Motors Speed Identification by Using Artificial Neural Networks Left-Inversion Method
Authors: Jiang Yan , Liu Guo Hai , Zhao Wen Xiang , Chen Ling Ling
Published: January 2011

A new speed identification method is proposed for sensorless operation of interior permanent-magnet synchronous motors (IPMSMs). The theoretic invertibility of mathematic model of IPMSMs is derived, and then a speed estimation strategy based on artificial neural networks left-inversion (ANNLI) is proposed. The structure of multi-layer feed-forward neural network is trained by advanced back propagation arithmetic. The effectiveness of the proposed method is verified by computer simulation. The results show that the developed control system can track the rotation speed quickly and accurately.
The Design of Program for NTC Automatic Tool Change Based on S7-300
Authors: Deng Chang Qi , Li Bin
Published: January 2011

The paper introduced the technical process of components and tool change of NTC, and analyzed the details of control of programmable logic controller (S7-300) in NTC. By adopting single-step operation,single cycle operation and sequence control devices, the control combines the Siemens configuration WinCC and WINCC analog simulation. The whole control fraction adopts hydraulic pressure to control, and the most famous advanced modeling and simulation platform for engineering system in the world, AMESim, is used in hydraulic part for modeling and simulation.
Optimization of Two-State Adjustable Damping Shock Absorber
Authors: Fan Jiu Chen , Sun Xue Mei , Chu Ya Xu , Li Xue
Published: January 2011

To improve the damping effect of vehicle shock absorber, a two-state adjustable damping shock absorber was designed using optimal design method. The size of the shock absorber damping hole and the valve parameters were optimized to obtain the optimal solution. According to optimal results, the piston speed and corresponding damping force of soft and hard damping conditions of the shock absorber were analyzed using MATLAB software. The results show that the simulated resistance curves and the ideal curves are in good agreement, which could provide guidance for the design and optimization of shock absorbers.
Study on Characteristics of Stress and Parameters Influence in Microscale Laser Shock Peening
Authors: Fan Yu Jie , Zhou Jian Zhong , Huang Shu , Wang W. , Wei Deng Hui , Zhu W.
Published: January 2011

Microscale laser shock peening (μLSP) can generate beneficial compressive stress distribution in the targets, as the used beam diameter in μLSP is at the order of micron equivalent with grain size, the treated material must be considered as anisotropic and inhomogeneous, this causes an asymmetrical distribution of residual stress. In this paper, shape factor σSF was introduced and defined to characterize the asymmetrical distribution of stress, optimum conditions of factors and the influence degree were explored based on Taguchi design with the optimal object of stress characterization values. The results show that shape factor is a significant characteristic of residual stress induced by μLSP, crystal orientation is the most important influence factor, but laser energy and peening number have significant influence on stress characterization values.
Development of Quick and Safe High Building Escape Method and Machine
Authors: Zhang Xi Liang , Gao Xin Ming , Gao Wen Xiang , Yao Qing , Li Bo Quan , Pan Hai Bin
Published: January 2011

With the socio-economic development and increasingly higher buildings, public concern is growing over high-rise fire evacuation issues. Considering the shortcomings of the existing escape device and methods, such as difficult speed adjustment, high demand for escaping skill, difficult unification of speediness and security, poor recycling etc, an integrated speed limited escape method is proposed by analyzing kinetics of high-rise evacuation. On one hand, the escape acceleration is limited by using centrifugal mechanism, on the other, according to the building height and people's weight, the landing speed of people is restricted by controlling the break height and braking force of brakes. The developed escape machine use the micro-controller to monitor the height and speed real-timely, control the brake automatically and start rope recycling mechanism after the landing, which achieves quick and safe escape. The experiment shows that when heavy object weighing around 75kg drops from a height of 14. 6m, the maximum speed reaches 3m/s, the landing speed is less than 0.5m/s and the falling time is within 7.5s, which achieves better escaping effect.
Modeling and Simulation of Dynamic Characteristics of the Linear Rolling Guide in Turn-Milling Centre
Authors: Zhu Li Da , Wang Wan Shan , Yang Jian Yu , Yu Tian Biao
Published: January 2011

In order to analyze accurately the dynamic characteristics of Linear Rolling Guide during the design stage, the Linear Rolling Guide that springs and damping units imitate joints is simulated by finite element methods in this paper. The proposed method can predict the regular pattern which joint stiffness and joint span affect natural frequency and harmonic response. The research demonstrates that the method predicts well the dynamic characteristics of the Linear Rolling Guide; therefore, it can be a reference for dynamic optimization design of Linear Rolling Guide in turn-milling center.
Theoretical Research on the Radial Stiffness of Pre-Loaded Hollow Cylindrical Roller Bearings
Authors: Wei Yan Gang , Liu Yan Kui , Zhang Xiu Juan
Published: January 2011

For solving the problems of classical mechanics on the stiffness of hollow cylindrical roller bearings, the radial stiffness of pre-loaded hollow cylindrical roller bearings is analyzed with finite element method and the elastic deformation of inner and outer rings is also taken into account. The effects of load, interference magnitude, and hollow ratio on the bearing stiffness are researched fatherly. The results show that the bearing stiffness correlates not only with the interference magnitude and hollow ratio, but also with load, which offers the references for designing and using the pre-loaded hollow cylindrical roller bearings.
Experimental Investigation of Ultrafast Thermalization Dynamics on Nickel Thin Films
Authors: Ren Nai Fei , Chen Qiu Yue , Xu Mei Ling , Jin Wei Feng
Published: January 2011

In order to break the limitation of the speed of magnetic installation due to magnetic layer transfer characteristics, the ultrafast thermalization dynamic of Ni films and its composite films were studied by femtosecond laser pump-probe technique. The paper focuses on the research of the effect of cooling layer and annealing on the transient reflectivity curves. And the transient reflectivity signals of Ni films prepared under different parameters were measured. The results show that the cooling layer with the larger electron heat capacity constant and the stronger electron-phonon coupling constant can enhance the scattering efficiency of transient heat conduction. Compared to the unannealed sample, the composite film sample after annealing has faster recovery process.
Classification and Recognition of Plant Leaf Based on Neural Networks
Authors: Ye Ping , Weng Gui Rong
Published: January 2011

This paper proposed a novel method for leaf classification and recognition. In the method, the moment invariant and fractal dimension were regarded as the characteristic parameters of the plant leaf. In order to extract the representative characteristic parameters, pretreatment of the leaf images, including RGB-gray converting, image binarization and leafstalk removing. The extracted leaf characteristic parameters were further utilized as training sets to train the neural networks. The proposed method was proved effectively to reach a recognition rate about 92% for most of the testing leaf samples
Research on Patterning Principle of Electronic-Roller in Tufting Carpet Machine
Authors: Sun Jing Jing , Meng Zhuo , Shen Li Heng
Published: January 2011

Through collocating colorized yarns and patterning weaving, a variety patterns of tufting carpet are realized. Patterning system is the core in tufting carpet machine; its performance determines the whole machine’s performance and weaving quality. In this paper, the patterning principle of single electronic-roller such as electromagnetic clutch type, servo motor type and step motor type, and the mulriple patterning principle such as two types or more than two types Electronic-Roller, was researched, the corresponding patterning mechanisms was designed, the approach realizing various patterning ways in mulriple patterning was exposited. The patterning principle exposited in this paper solves the general problem in designing patterning mechanism. The patterning systems developped on this principle have been applied in a variety of tufting carpet machines, and a variety of high precision carpet products have been woven.
Development of Recycling System for Fiber-Reinforced Plastics by Superheated Steam
Authors: Shi Jian , Wada Shougo , Kemmochi Kiyosi , Bao Li Min
Published: January 2011

A recycling system was developed for the treatment of fiber-reinforced plastics (FRP) by superheated steam. The process was shown to be robust, coping with scrap of FRP and providing useful outputs in the form of recovered fibers and resin. In this study, glass FRP (GFRP) was decomposed at a chamber temperature above 370°C. Fibers were collected at purities of up to 80%. The tensile strength of recovered glass fibers was reduced by up to 50% although this depended on the temperature of treatment. Resin was separated from the gas stream by cooling it to liquefaction temperature of resin.
Water Level Control Embedded Fuzzy-PID and Pole-Placement Strategy
Authors: Yu Biao , Zhu Hui
Published: January 2011

Since boiler water level system is a complex dynamic system, it is difficult to obtain satisfactory control performances by using the traditional PID controller whose parameters are constant. Therefore, an intelligent fuzzy-PID controller, which can adjust the three parameters of PID in terms of the level error and the rate of lever error, is proposed. On the other hand, if knowing the relation between the closed-loop poles and the system performance, we can achieve the desired control characteristics with pole-placement approach. So, a new control strategy combined with PID controller, fuzzy logic and pole-placement design through state feedback is further proposed. The simulation results show that this control strategy has much better performances than is obtained with traditional controllers.
Study on the Drawing and Trimming Springback Characteristics of Hyperboloid Shallow Shell of Tailor Welded Blanks
Authors: Jiang Yin Fang , Li Zhi Fei , Tang Zhen Zhou , Fang Lei
Published: January 2011

With more and more attention to the technology of tailor welded blanks (TWBs), it is vital to study the springback of TWBs. In this paper, the springback law of parallel and perpendicular to the weld of TWBs hyperboloid shallow shell affected by blank holder force, punch string height, and the difference of blank thickness was researched by finite element software. The results show that: by means of drawing and trimming, the springback of TWBs can be reduced, and the curvature of TWBs is less parallel to the weld, but the curvature is larger perpendicular to the weld. The effect of blank holder force on the trimming springback is relatively small in the range of experimental date. With the punch string height increasing, the drawing and the trimming springback are both increased firstly and then gradually decreased perpendicular to the weld, and the drawing and the trimming springback are both decreased parallel to the welding. And perpendicular to the weld, with the increase of the quadratic difference of thickness, the drawing springback of the thinner side is gradully decreased, and the drawing springback of the thicker side is gradually increased, after trimming, the springback of the thinner and the thicker side are both less than the drawing springback, and parallel to the weld, the drawing and the trimming springback are decreased firstly and then increased with the increase of the quadratic difference of thickness.
The Numerical Optimization of Laser Shot Peening Parameters Based on Response Surface Analysis
Authors: Jiang Su Qing , Wu Jian Hua , Xu Hong Guang , Zhou Jian Zhong
Published: January 2011

Residual stress field induced by laser shot peening (LSP) was simulated using Box-Behnken experimental design. Compressive residual stress field intensity (S) was introduced to estimate the effect of compressive residual stress field on fatigue performance. The effect of laser process parameters (such as laser shock wave peak pressure, spot diameter and peening number) on S was analyzed by response surface analysis (RSA), quadratic regression predicting model for S was established, and the rationality of that was verified. Finally, the optimal combination of laser process parameters oriented to anti-fatigue manufacture was optimized. The results indicated statistical analysis results agreed well with those of simulation, RSA for parameter optimization of LSP is feasible.
Effect of CO2 Laser Surface Melting on the Microstructure of AZ91D Magnesium Alloy
Authors: Chen Ju Fang , Li Xing Cheng , Wang Jiang Tao , Lei Wei Ning
Published: January 2011

In the present study, the effect of laser surface melting (LSM) on microstructure of AZ91D magnesium alloy was investigated with a 2kW continuous wave CO2 laser. The results indicate that both the substrate and laser melted layer mainly consisted of α-Mg and β-Mg17Al12, the amount of β-phase in laser melted layer was decreased as compared to that of the substrate. The microstructure of the laser surface melted zone consists of fine dendrites with an average grain size of less than 10m, the grain size was reduced by a factor of more than 10 times as compared to that of the substrate. The micro-hardness of the melted layer was increased to 70–85HV as compared to that of the substrate (about 53HV). Because of the grain refinement, the enhancement of the hard phase β-Mg17Al12, and the solid solution hardening of alloy elements, the micro-hardness and strength of the laser melted layer was increased significantly.
The Effect of Heat Treatment on the Microstructure of Electroless Ni–P Coatings
Authors: Cheng Yan Hai , Zhu Zhen Cai , Han Zheng Tong
Published: January 2011

In the paper, different phosphorus content Ni-P coatings was prepared by electroless plating. The microstructural changes of electroless Ni-P coatings on both as-deposited condition and heat treatment were investigated by X-ray diffractometry (XRD). The relationship between microstructure of Ni-P coatings and phosphorus content and heat treatment temperature were discussed. This conclusion provided a good theoretical basis for Ni-P coating using for wear and corrosion resistances in the technology of MEMS.
Experiment of Laser Shock Processing on AISI 8620 Alloy Steel
Authors: Shen R.H. , Lu J.Z. , Zhong J.W. , Zhang L. , Luo Kai Yu , Zhang Y.K.
Published: January 2011

Laser shock processing (LSP, also known as Laser shock peening) is applied by using a high energy pulsed laser to create a high amplitude stress wave or shock wave on the surface to be treated. LSP is proved to be superior to conventional treatments such as shot peening in many engineering products. This paper focuses on Laser shock processing and its effects on mechanical properties of material AISI 8620 alloys steel. Experiment results indicated that compared with base material, the surface hardness increased by 13.8%, and compressive residual stress increased by 521%. Statistical method was introduced to analyze hardness and residual stress change before and after the LSP.
Interfacial Reaction of Ni (P)-Sn Coating on Magnesium
Authors: Ge Xiao Lan , Wang Cai Jun , Chen Zhi Chao , Zeng Bing , Wei Duo
Published: January 2011

Hot dip tin coating was obtained on AZ91D magnesium alloy surface, and interfacial reactions between Sn coating and electroless Ni-P plating was studied. The results show: after 220±5°C, 2h diffusion, the intermetallic compounds possessed corresponding thickness, and Ni3P layer along the interface acted as a good diffusion barrier between Sn and Ni. When Ni3Sn4 spread to the surface, microcracks were observed on the surface. Corrosion resistance of Ni(P)-Sn coating before and after diffusion was investigated with polarization curves. The results show: Ni(P)-Sn coating significantly enhance the corrosion potential of base material, but after the Ni3Sn4 growth to the surface, it caused electrochemical corrosion and decreased the corrosion resistance.
Effect of Volume Fraction of Nanoparticles to the Convective Heat Transfer of Nanofluids
Authors: Ling Zhi Yong , Zou Tao , Ding Jian Ning , Cheng Guang Gui , Fu Peng Fei , Zhang Ti Feng , Zhu Ai Jun
Published: January 2011

A numerical study on the convective heat transfer characteristics of Cu-water nanofluid under the laminar flow condition was performed. The results show that the convective heat transfer coefficient increases with the increase of the volume fraction of the nanoparticles and the Reynolds number. There is a significant difference between the numerical simulation result and the result calculated from the Shah equation in the entrance region, but a small difference in full development areas. The numerical results agree well with that obtained from the Xuan equation when the Reynolds number and the volume fraction of the nanoparticles are small, but the errors between them increase as the increase of the Reynolds number and the volume fraction of nanoparticles.
Over Voltage Protection Device Based on Multi-Strategy
Authors: Zhang Hai Tao , Li Gang
Published: January 2011

Strong electromagnetic interference occurs when the locomotive was running. Therefore, measurement errors resulted from interference exist when monitoring the rail potential only at single point. This will lead to misoperation of the protection device. An over voltage protection device based on multipoint and multi-strategy was designed. The mathematical model of rail potential distribution was built. Fuzzy neural network and multi-sensor monitoring technology were applied in this design. The emulation analysis demonstrated that the proposed device has better reliability and higher control accuracy than the single strategy approach.
Investigation on Fatigue Performance of TC4 Alloy by Laser Shock Processing with Different Processing Parameters
Authors: Luo Kai Yu , Dai Feng Ze , Zhang L. , Zhong J.W. , Guan Hai Bing
Published: January 2011

In the present investigation, the effects of processing parameter on three-point bending fatigue pergormance of TC4 alloy are examined, particular emphasis is devoted to the question of appropriate LSP processing parameters for improving the fatigue properties. Based on cyclic deformation and stress/life (S/N) fatigue behavior, it was found that there was the optimal shock number of overlapped spots for three-point bending fatigue pergormance of TC4 alloy. By comparing with the as-received specimen, the fatigue performance of TC4 alloy has the most obvious improvement by LSP with two impacts.
Effects of Processing Parameters on the Laser Deposited Co-285 + WC Coatings
Authors: Sun Gui Fang , Zhou Rui , Li Peng , Zhang Yong Kang
Published: January 2011

Laser-aided direct metal deposition (LADMD) technique was used to fabricate Co-285+WC coatings on 1018 mild steels. The effects of the processing parameters (laser power P, addition amount of WC, scanning speed V) on the microhardness of the deposited coatings was analyzed. Results indicate that the microhardness of the matrix and the Rockwell hardness of the deposited coatings increases with the addition of WC and the P/V value. The addition amount of WC has the most important effect on the two hardness values, followed by the scanning speed and the laser power. Results of the optimized specimen in this study indicate that the deposited coating is composed of undissolved WC, dendrites, eutectics and the coral structures. The wear mechanism of the deposited coating is a mixture of abrasive, adhesive and oxidation wear.
Analysis of the Thermal Response in Micromachine under the Thermal Shock
Authors: Wang Ying Ze , Song Xin Nan
Published: January 2011

The thermal response for given micromachine with the boundary surface exposed to sudden temperature change is studied by deriving an analytical solution of the hyperbolic heat conduction equation. Using the obtained analytical expression, the temperature profiles at the outer surface and interior of the micro beam are evaluated for various thermal relaxation times. The behaviors of hyperbolic heat propagation in micro beam are analyzed and possible anomalies are discussed by comparing the thermal behaviors of Fourier heat conduction.
The Effects of the Expander Lens on the Output of the High Energy Nd: Glass Solid-State Laser
Authors: Guan Hai Bing , Zhang Yong Kang , Ye Yun Xia , Cui Cheng Yun , Qian Xiao Ming , Wu Zhong
Published: January 2011

The expander lens can match the beam dimension between two cascade amplifiers, so the laser medium can be used effectively and the laser output energy can be improved greatly. Study on the functions of the expander lens in high energy Nd:Glass laser is presented. It is shown that the output energy increases by 30% with the expander lens. The simulation through using the optical software CodeV indicates that adjusting the expander lens can effectively compensate the laser thermal lens, make the focusing beam into the parallel beam, and avoid damaging the optical elements. In addition, adjusting the expander lens may compress the laser beam divergence and focus the laser spot, which is beneficial to form high power density and meet the requirements of laser shock processing.
Microstructure Evolution of Pearlitic Lamella Impacts at Ultra-High Strain Rates
Authors: Xiong Yi , He Tian Tian , Zhang Fang Yu , Zhang Ling Feng , Ren Feng Zhang
Published: January 2011

The microstructure evolution of eutectoid steel with lamellar pearlite was investigated by SEM and TEM during ultra-high strain rate loading. The results indicate that ultrafine microduplex structure (ferrite + cementite) with the grain size to sub-micrometer level was observed at the surface of eutectoid steel after single pass ultra-high strain rate loading. Equiaxed ferrite grain was about 0.8 μm and the cementite lamella was spheroidized fully, and the diameter of the cementite particle was about 50 nm. The bent or fractures can occur at the edge of shock wave. Ultra-high strain rate shocking induced severe plastic deformation at the surface of materials and the cementite lamella has better plastic deformation capacity.
Influence of Laser Shock Processing on the Weld Line and Finite Element Simulation
Authors: Zhang Jie , Sun Ai Hua , Zhu Le , Gu Xiang
Published: January 2011

Welding residual stress is one of the main factors that affect the strength and life of components. In order to explore the effect on residual stress of welding line by laser shock processing, finite element analysis software ANSYS is used to simulate the welding process, to calculate the distribution of welding residual stress field. On this basis, then AYSYS/LS-DYNA is used to simulate the laser shock processing on welding line. Simulation results show that residual stress distributions of weld region, heat-affected region and matrix by laser shock processing are clearly improved, and the tensile stress of weld region effectively reduce or eliminate. The simulation results and experimental results are generally consistent, it offer reasons for parameter optimization of welding and laser shock processing by finite element analysis software.
Phases Transformation Analysis of ZrO2 Ceramics after Laser Shock Processing
Authors: Zhang Ling Feng , Wang Yan Zhi , Xiong Yi , Lu Jin Zhong
Published: January 2011

Through phrase transformation analysis on ceramics samples after applied laser shock wave, study was made on micro-structure and mechanical performance transformation and transformation laws. Thus conclusions were drawn through analysis as follows: tensile stress was caused on back surface of TZP ceramics sample by laser shock wave, and further transformation was generated under tensile stress in a way that about 48% tetragonal phrases t-ZrO2 transformed into monoclinic phrases m-ZrO2, which expanded volume of and gave rises to micro-cracks, and relief stress and micro-cracks caused will absorb the energy of main cracks, which can impede expansion of main cracks and realize the aim of phrase transformation toughening.
Simulation and Experiment of High-Speed Dynamic Plate Deformation Process Shocked by Pulsed Laser
Authors: Tong Yan Qun , Yao Hong Bing , Zhang Yong Kang , Chen Ming Yang , Yuan Be , Meng Chun Mei
Published: January 2011

The deformation process of plate material shocked by high-power short pulsed laser is one of the key problems for laser shock forming. In this paper, the finite element software ABAQUS is used to simulate the deformation process. A simple and novel optoelectronic measurement system is applied to measure the deformation process of aluminum sheet. The experiment and simulation results show that the load from the high-power short pulsed laser irradiation can be regard as transient pressure and the dynamic displacement law is damped oscillation.
Monte Carlo Simulation of Light Distribution in Liver Tumors for 808nm Wavelength Laser
Authors: Hua Guo Ran , Zhang Hua , Qian Ai Ping , Lv Cao Jun
Published: January 2011

Propagation of 808nm wavelength laser beam in liver tumors was simulated with Monte Carlo method. Based on the distribution of light in normal liver and liver tumors, the temperature distribution inside tissue under laser irradiation has been retrieved. Furthermore, the influences of laser power and action time on the temperature field were studied. The results show that the normal liver and liver tumors have different light absorption with laser beam. The difference of temperature distribution in tissues with the same laser power is useful to be applied in control the treatment of laser-induced interstitial thermotherapy for liver tumors.
Effect of Strain-Rate on the Fracture Morphology of LY2 Aluminum Alloy by Laser Shock Processing
Authors: Lu Jin Zhon , Luo Kai Yu , Zhang L. , Zhong J.W. , Cui X.G. , Zhang Yong Kang
Published: January 2011

The strain-rate sensitivity of LY2 aluminum (Al) alloy subjected to laser shock processing (LSP) was investigated according to the fracture morphology at strain-rates ranging from 0.00001 s-1 to 0.1 s-1. The fracture morphology was observed by the scanning electron microscopy (SEM). Fracture morphology at different strain-rates suggested that LY2 Al alloy after LSP seemed to evolve towards a more ductile dimple fracture mode with increasing the strain-rates. The relations underlying the fracture morphology and strain-rate sensitivity were also addressed.
Microstructure of Laser Cladded Cobalt-Based Alloy Coating on T10 Tool Steel
Authors: Zhao Qian , Zhang Yong Kang , Cui Cheng Yun , Cui Xi Gui , Lu Jin Zhong
Published: January 2011

Co-based alloy coating was fabricated by powder feeding laser cladding on T10 tool steel. The microstructure and phase composition were investigated by scanning electron microscope (SEM) and X-ray diffractometer (XRD). The results showed that the different solidification microstructures on the section, such as planar, cellular and dendrite formed from the interface to the surface. The main phase γ-Co and another phase Cr23C6 existed in the original coating, however, the main phase γ-Co was unchanged, and another phase was replaced by Cr7C3 accompanying with Co3C and Co4B precipitations after aging treatment.
Calibration Method and Experimental Study of the Camera Internal Parameters Based on One-Step Movement
Authors: Zhu Xing Long , Zhu Jun Jun , Zhang Ying , Zhou Jj Ping , Gao Long Qin , Li Lu Yang
Published: January 2011

A calibration method based on target features circle is proposed, which can determine the camera internal parameters based on the two different CCD images. One CCD image can be obtained in a position, and the other CCD image can be gotten by moving the target or camera to a new position. The principle of the calibration method based on one-step movement is expounded. The geometrical relationship and the criteria that the camera axis is orthogonal to the target plane are proven when the CCD image is circle. Finally, the experiment results verify that the method proposed is effective, and the data of the internal calibration parameters of the camera is given.
Surface Modification of Polyethylene Film by Atmospheric Pressure Glow Discharge Liquid Deposition Polymerization
Authors: Jiang Xiao Mei , Rui Yan Nian , Chen Guo Qiang
Published: January 2011

In this paper, polyethylene film was treated by APGDLD (atmospheric pressure glow discharge liquid deposition) to polymerize acrylic acid onto the surface to improve its hydrophilicity. The effect of APGD and APGDLD on the surface modification is compared. Influence of various treatment conditions on polymerization degree and contact angle such as applied voltage, discharge gap, reaction gas flow rate and treatment time were investigated. Treating effect was characterized via contact angle measurements, SEM and ATR-FTIR. The results indicated the hydrophilicity of the polyethylene film surface was enhanced and well reserved by APGDLD.
The Pyrocarbon Deposition Techniques of Mechanical Heart Valve Prostheses
Authors: Zhang Jian Hui , Chen Xin
Published: January 2011

The structure and property of pyrocarbon varies widely with different deposition conditions. The isotropic carbon which can only been deposited in the bed of fluidized particles is very important in biomedical fields, for instance, it is often used as the coating of artificial heart valve components. The deposition of isotropic pyrocarbon containing silicon is experimented in fluidized bed over a wide range of deposition conditions. The results show that bed temperature influences strongly average coating rate, coating density, silicon content and coating micro-hardness. Propane concentration has a much effect on coating density, carbon matrix density and isotropic characteristics. Total gas flow rate and inlet dimension of fluidized bed affect the formation of fluidized bed.
Simulation and Test Analysis of the Torque Ripples of Brushless DC Motor for Electric Vehicles
Authors: Li Zhong Xin , Zhu Xing Liang , Jiang Hong
Published: January 2011

A new control strategy was proposed to restrain the torque ripples of brushless DC motor (BLDCM) when starting an electric vehicle. Based on the mathematical model of BLDCM, a double loop model of the BLDCM drive system was established using Matlab/Simulink. A PID controller was used in the speed loop, and a current controller based on hysteresis characteristic was implemented in the current loop. The simulation results were compared with the experimental results obtained in the drum test using an electric vehicle which was developed by the research institute. It was found that the control strategy and the motor controller exploited by the research institute met the technical requirements of starting process for the electric vehicle. The torque ripples of BLDCM were suppressed and the simulation model was validated.
Research on Sensor Fault-Tolerant Control Based on Riccati Equation for Electric Power Steering
Authors: Wang Da Chong , Long Chen , Huang Chen
Published: January 2011

In order to ensure the safe and reliable operation of electric power steering(eps) system,the fault-tolerant control theory is used to design the feedback control for eps system and the control rule for sensor failure in the linear continuous system is described.On the basis of riccati equation,the design method and steps of fault-tolerant controller are given from the view of optimal control.By taking electric power steering of a certain mini car as research object,the simulation calculation is carried out.By applying such fault-tolerant controller for the eps system,the simulation results show that the system has no sensitiveness to the sensor faults,and the method can satisfy the demand of fault-tolerant control.
Investigation of a Micromixer for the MTPV System
Authors: Cheng Guang Gui , Ding Jian Ning , Ling Zhi Yong
Published: January 2011

In this paper, a micromixer used in micro thermo photovoltaic system (MTPV system) is simulated and fabricated. The optimal structure parameters were investigated by computational fluent dynamical software (CFD)，during the simulation, three main parameters n,τ and δ were introduced to studied on the influence of the mixing intensity . The simulation results show that the number of the static elements added in the mixing channel n should be more than 4, the side-length of the static elements should be half of the channel’s width and the static elements should be equidistant and interlaced distribution.