bluuebunny/crossref_metadata_2025 huggingface dataset:
A Fault Diagnosis Method Based on Improved Grey Correlation Grade for Turbine Generator Unit
Authors: Xu Chun Mei , Zhang Hao , Peng Dao Gang
Published: November 2011

Analyzing grey correlation grade method, a fault diagnosis method of improved grey correlation grade is presented for turbine generator unit. The method calculates weight according to test sample, and then calculates the weighted grey correlation grade. And for the characteristics of turbine generation unit, a fault diagnosis method based on improved grey correlation grade is presented. Simulation results show that the proposed method can successfully diagnose all fault of turbine generation unit, and fault isolation capability is much stronger than traditional grey relation.
Study on Cable-Stayed Bridge Flutter Active Control by a Single ADM
Authors: Qi Su , Chen Xing Xing , Xu Qing
Published: November 2011

Wind-induced vibration of long span bridges mainly as flutter, buffeting and vortex induced vibration. Buffeting and vortex-induced vibration will not cause the devastating destruction of the bridge, while the chatter is the elastic system in the air of self-excited vibration, when the vibration system from the air flow in the absorption of energy and the energy is greater than the energy damping When consumed, they cause divergence of the self-excited aerodynamic flutter vibration. If the critical flutter wind speed is less than in the bridge office potential wind speed, the bridge flutter may occur caused devastating damage. According to modern control theory, a theoretical analysis is conducted on the active control of cable-stayed bridge flutter, it is established that the controlled equation of cable-stayed bridge controlled by a single active mass damper and the motion equation of a single AMD to determine the calculation method of the critical flutter velocity under the controlled status of the cable-stayed bridge. An example shows that a single ADM is a good means to prevent the flutter damage of long-span cable-stayed bridges.
Twelve-Position Calibrating Method without North Using for Three-Axis Magnetic Sensor
Authors: Li Ding , Wo Song Lin , Bu Xiong Zhu
Published: November 2011

In allusion to the compensation of environmental magnetic field for using three-axis magnetic sensor, a twelve-position calibrating method without north is designed. The equations of three-axis bias, scale factor error and install alignment error are deduced in the proposed method which is totally based on the magnetic field of up direction. According to the effect of hard iron and soft iron is equaled to the variation of three-axis bias, scale factor error and install alignment error, comparison experiments are completed in natural conditions and in conditions that the effect of hard iron and soft iron is artificially imposed. The experiment shows that this method can solve the compensation of hard iron and soft iron interference effectively for the application of up direction tumbling test.
Meshing Theory of New Epicycloids Gear Drive
Authors: Xue Yun Na , Wang Yong , Wang Zheng
Published: November 2011

In order to realize the pure rolling, improve the contact ratio, remove the backlash and raise the life, a new epicycloids gear drive is put forward. The drive part of the particular mechanism is a wheel with the roller tooth and is called the roller gear. And the driven part is the epicycloids gear. The tooth profile equation is achieved and meshing characteristics is also studied. The basic parameters of the new mechanism are researched and the 3D model is achieved. The research result shows that the new drive is workable and the new mechanism has a wide application prospect.
Analysis of Ramp Estimation Algorithms in Automatic Transmission
Authors: Tian Yuan Suo , Ding Zhi Zhong , Wang Qiong , Sun Bao Qun
Published: November 2011

Automatic transmission may produce busy shifting on uphill and downhill. This article analyzes three algorithms about the estimation of road ramp: the first using a longitudinal acceleration, the second using estimated output torque, and the third using the difference between two accelerations. The first method is more accurate than the other two, but it is more expensive because an additional acceleration sensor is needed. The second is more complicated and in some driving conditions, it could not estimate the output torque. The third is based on simple theory and inexpensive since no additional sensor is needed. Some simulation results of avoiding unnecessary gear-shifting are also presented in the paper.
The Software Design of a Gas-Liquid Separation and Metering System
Authors: Shen Hua Dong , Xiao Xin Hua
Published: November 2011

On many occasions, gas phase and liquid phase of original mixture needed to be measured in the processes of petroleum, chemical, natural gas and other industry. A system of gas-liquid separation and metering were studied deeply in this paper. Kingview was taken as the software of the system. It realized dynamic show of the system state and generated various reports. Three of the functional modules were mainly introduced in the software design. The nucleus part of the system was the PID module. Its function was to regulate the aperture of the valve properly. The interface design of supervisory and report management is also described in detail. The testing on the spot has proved that system function and accuracy can meet the needs completely. The system has the characteristics of reasonable structure and stable performance. It provided a better solution to the means of gas-liquid separation.
Soot Mass Flow Measurement System Using Triboelectricity and Ultrasonic
Authors: Zhao Yan Jun , Zhao Xuan , Yue Shu Sheng
Published: November 2011

A new method, triboelectricity and ultrasonic, for the soot mass flow measurement is developed. The direct rod-shaped sensor is used to measuring the triboelectricity charge and the ring sensor is used to measuring the electrostatic induction charge. The pure-triboelectricity can be figured out and the pure-triboelectricity is eliminated the influence of the electrostatic induction. Through the numerical simulation, the proportion between the electrostatic induction charge and the electrostatic induction charge is presented. The gas flowrate is measured by the ultrasonic. The soot mass flow can be figured out through the pure-triboelectricity and the gas velocity. Additionally, the sample calibration equipment based on the pure-triboelectricity and ultrasonic method is also introduced. Experimental results show the method can on-line measure the soot mass flow.
Vibration Signal De-Noised by Alteration Wavelet Transform under Alpha Stable Distribution Environment
Authors: Qin Xu , Zha Dai Feng
Published: November 2011

In vibration measure the signal processing system of Gaussian model was abnormal for the pulse noise environment. So it was necessary to find other model and transform the traditional signal processing method. Studies showed that the Alpha stable distribution was better to describe these non-Gaussian signals. After studying the property of Alpha stable distribution and the fractional lower order statistics theory, we altered the wavelet transform. The method was that the fractional lower order statistics replaced the 2-order statistics in the traditional wavelet algorithm. Experimental vibration measure system including some sensors on the spindle or other measure points collected the vibration signals and sent to computer. The results show that the alteration wavelet transform system can effectively restrain the pulse noise and reduce the signal distortion. The new signal processing system can achieve the generalized de-noising function including re-Gaussian distribution.
Buckling Analysis of Functionally Graded Super Elliptical Plate Using Pb-2 Ritz Method
Authors: Jazi Saeid Rasouli , Farhatnia Fatemeh
Published: November 2011

In this paper, buckling analysis of functionally graded super-elliptical plates is investigated by pb-2 Ritz method. The governing equation is derived based on classical plate theory (CLP). Since closed form solution of buckling differential equation is not available under various boundary conditions, pb-2 Ritz method (energy method) is applied to calculate non-dimensional buckling load. Total potential energy is given as summation of strain energy and work done by applied in-plane compression load. In order to obtain the buckling load, pb-2 Ritz method is applied corresponding to different peripheral supports (Clamped and Simply Supported) are used in the present study. The plates are assumed to have isotropic, two-constituent material distribution through the thickness and the modulus of elasticity of the plate is assumed to vary according to a power-law distribution in terms of the volume fractions of the constituents. Variation of buckling non-dimensional parameter is considered with respect to various powers of super–elliptic, FGM power law index and aspect ratio.
Multi-Sensors Information Fusion Based on Momentis Method and Euclid Distance
Authors: Lang Feng Yong , Li Xiao Gang
Published: November 2011

A method based on data level fusion for solving the problem of multi-sources information fusion is discussed in this paper. Firstly, the credibility of multi-sources information is calculated based on the Euclid distance. Calculating the distance between the multi-sensors information and the experiment data, the shorter the distance is the better the degree of association between prior information and the population information is. The distance of multi-sources information is normalized to be the credible weight. Secondly, the unknown parameters of various probable distribution function is estimated with momentis method, in order to establish an optimal fused prior distribution. According to the momentis method, different random variable may have the same expectation and variance, in this paper we take some distribution function commonly seen for instance. Finally, demonstrations are carried out with MATLAB simulation to validate this method.
Research on Rotation Vector Algorithm in Untypical Conic Motion
Authors: Dong Ming Jie
Published: November 2011

This paper made a detailed analysis to calculate equivalent rotation vector of vehicle in untypical conic motion, and put forward a method to imitate the real motion of vehicle. The paper first studied comprehensively the influence on vehicle information such as attitude angle, speed, position, etc, calculated by angle-increment attitude algorithm with different samples in untypical conic motion. The general result is figured out. And this paper provided reference for choosing attitude algorithm in practical projects.
Realization of Active Vibration Control on Piezoelectric Intelligent Flexible Beam
Authors: Wu Da Fang , Huang Liang , Su Fei , Liu Cheng Xiang , Yang Hong Yuan , Liu An Cheng
Published: November 2011

In this paper, the principle and method of active vibration control of a flexible cantilever beam with PZT actuators was studied. A strategy of active control on the first and second order vibration mode of the flexible cantilever beam are determined and implemented by using the independent modal control. Eexperimental results show that the structural damping of the flexible cantilever beam is improved effectively and excellent effect of vibration suppression is achieved with the control strategy.
Modeling and Simulation of Helicopter Cabin Electromagnetic Environment
Authors: Yang Liu , Jia Yun Feng , Su Dong Lin
Published: November 2011

Electromagnetic environment (EME) in helicopter cabin is one of the most important indexes for electromagnetic compatibility (EMC) on airborne platform. The simulation results were not accurate enough because of the difficulties in accurately modeling and the large computation. Due to the inaccuracy of the former modeling method which used the typical geometric, the professional software ICEMCFD/AI*Environment (AIE) was employed to restore the helicopter’s original model, based on the obtain of the accurate helicopter model, the Multi-layer Fast Multipole Method (MLFMM) and Combined Field Integral Equation (CFIE) were employed to analyze the variation of the electric field in the helicopter cabin versus the frequency and other factors with a VHF antenna mounted on the helicopter. Both accuracy and computing speed were concerned, the results have some guidance significance to the EMC preliminary design on airborne platform.
Tubular Permanent Magnet Linear Synchronous Motor Thrust Optimization
Authors: Zhao Jing Hong , Zhang Jun Hong
Published: November 2011

Detailed discussion design parameters selection process of thrust density optimization about the tubular permanent magnet linear synchronous motor. Analysis of different parameters on the thrust density laws. Two different magnetization forms linear motor is optimized. The optimal design parameters value is obtained. Finally analysis and comparison of the two structural features of linear motor. The motor design guide has practical engineering value.
Analysis of Reliability for Hoist Main Control System Based on Markov Process
Authors: Wang Feng , He Feng You , Li De Chen
Published: November 2011

A reliability mathematical model of the hoist control system based on Markov process was developed and a formula of availability and reliability of the system was derived. At the same time a redundancy-based technology was introduced to improve the reliability of mine hoist control system according to the special requirements of safety and reliability. A new way of thinking is provided to further study the reliability of similar control system through the reliability study of hoist control system.
The Design of Mini Quad-Rotor Unmanned Aerial Vehicle Control System
Authors: Zhao Ying , Yang Jian Xu
Published: November 2011

In this paper we describe a small four-rotor UAV's autonomous flight control system. A comprehensive plan of flight control system was designed base on the remote control model aircraft for flight platform, and Completed with AVR microcontroller core flight control system software and hardware design. It including device type, hardware circuit design and software design. Preliminary study of the four rotor while the helicopter flight control program design, For the future to perform more complex tasks such as fixed-point flight, obstacle avoidance and coordination of multiple aircraft flying and so lay a foundation.
On Current Situation and Development of our Industrial Automation Control Technology
Authors: Li Jing Min
Published: November 2011

The industrial automation control technology is comprehensive technology, mainly including industrial automation hardware, software and systems which reaches inspect, control and optimization, scheduling, management and decision-making, and increases yield and improve quality, reduce cost, to ensure safety. Industrial automation control technology as the most important technology in modern manufacturing in 20th century, which mainly solve the problem of production efficiency and consistency. Although automation system itself is not directly creating benefit of enterprise production, but it has obvious effect of ascension process. Our industrial automation control development road, mostly in the introduction of complete sets of equipment, and at the same time the digestion and absorption of second development and application. Currently our industrial automation control technology, industry and applications have developed greatly in industrial computer system, has been formed. At present, industrial automation control technology is intelligent, network integration and development direction
Cascaded Control Allocation in Overactuated Aircraft via Mixed Optimization
Authors: Chen Yong , Dong Xin Min , Chen Ya Li , Wang Long , Guo Jun , Li Hong Bo
Published: November 2011

This paper presents the principle and application of a class of cascaded optimal control allocation approach for overactuated aircraft. The design is based on mixed optimized targets consisting of two parts: the tracking error of virtual control and the effectors’ error related to the preferred control vector. At each step, the unconstrained least square problem is solved through simple calculation to obtain the optimal solution. If any optimal commands exceed the position limit or rate limit, a scheme is designed to choose at most one effector set to its limit and the remaining virtual controls are redistributed among other unsaturated control effectors. The Simulation based on the ADMIRE model shows that the effectiveness of the proposed approach comparing with Cascaded Generalized Inverse and Fixed-Point Method.
Velocity Servo Design of Auto-Disturbance-Rejection Controller for Permanent-Magnet Synchronous Motor Servo System Based on Feedforward Compensation Controller Including Sliding Mode
Authors: Bai Jing , Xin Ping , Ma Dan Dan
Published: November 2011

To solve the horizontal speed of shear blade demanded strictly maintain synchronous speed with plank in shear zone, a feedforward compensation controller including sliding mode controller is proposed as the velocity controller to improve the system performance, which has the merit of the small chattering and good robustness. The simulation shows that this method improve dynamics and robustness of system effectively despite of load abrupt change and system parameter change.
Design of Intelligent Rehabilitation Crutch Based on Accelerometer
Authors: Guo Hong Che , Ma Jun Bao , Zhang Qiu Hao , Yang Jun You
Published: November 2011

In order to meet the daily needs of the elderly patients and walking ability of injury rehabilitation, design an intelligent rehabilitation crutch. This design combine with empowered walking aid’s mechanical features and robot technology, its signal is collected by MMA7260 accelerometer, this greatly improved the sensitivity direction without swerve on the plane through the analysis of the acceleration signal processing and controlling the velocity composition of three omnidirectional wheel rounds of synthesis of all to realize the intelligent walking stick of the whole direction and intellectuality of the walking aids. The motion mechanism of crutch using omnidirectional wheel structure and using ATmega 16 microcontroller to establish low-level control system. The crutch can move in any n of free movement. The kinematics analysis shows the design feasibility. In the manual and automatic control experiments, it can meet designer quarrymen’s and achieve design function.
Research on Error-Tolerant Model of Master Control Computer for Electronic Automation System
Authors: Du Shuang Yu , Wang Xian Pei , Yang Tong Zhong
Published: November 2011

The power system operates safely and stably depends on the reliable operation of electric automation system of which the master control computer is the core. To improve the reliability,security and real-time performance of the master control computer, the error-tolerant model of master control computer based on replication technology for electronic automation system is built and the implementing method of model is introduced in great detail. For the defects of dual-computer hot backup system and on the basis of three-machine voting system, the error-tolerant model of master control computer designed in this paper makes some improvements in system structure and voting algorithm ,so as to provide a reference for the construction of electronic automation system in the “strong” and "self-healing" smart grid.
CFD Simulation of Mixing Effects in Gas-Liquid-Solid Stirred Reactor
Authors: Xu Jian Xin , Wang Hua , Wang Jian Jun , Wang Shi Bo , Zhu Dao Fei , Fan Guo Feng
Published: November 2011

In order to analyze the complex phase transition in the gas-liquid-solid three-phase mixing systems and to predict gas-liquid-solid multiphase mixing time, a novel method combined image processing technology, computational homology and CFD (Computational Fluid Dynamics) numerical simulation is introduced in this study. Firstly, the volume of fluid (VOF) multiphase flow model in FLUENT software is used for the simulation of fluid characteristics. Secondly the patterns produced by phase transition in the stirred tank are binaryzed. Finally evolution profile of the zeroth dimensional Betti numbers and the first dimensional Betti numbers in time series are obtained separately. In fact,some aggregates still remain in the tank after the homogeneous mixing.Comparing with the fractal method to characterize the mixing time, the result shows that this method not only can predict the gas-liquid-solid mixing time by the zeroth dimenstional Betti numbers, but also can predict the amount of these aggregates in the stired tank by the first dimenstional Betti numbers, leading to a useful parameter to characterize the non-uniformity of gas-liquid-solid mixing.
Simulated Programming Characteristics of Stacked-Gate Flash Memories with High-k Tunnel Dielectrics
Authors: Chen Yung Yu
Published: November 2011

Due to the reduced gate coupling ratio, the channel Fowler-Nordheim (CFN) programming speed of stacked-gate flash memories with high-permittivity (k) tunnel dielectrics (TDs) is helpless in operation voltage reduction. Although the electric field on high-k tunnel dielectrics is lower than SiO2 tunnel oxide, enhanced impact ionization rate and lower barrier height contribute to higher channel hot-electron (CHE) injection current and efficiency. Consequently, high-k TDs are only effective for the memories programmed with hot electron injection rather than FN tunneling, which is suitable for the NOR-type stacked-gate flash memories.
Design of Smart Car Servosystem Based on Camera
Authors: Zhang Lu , Song Qiu Hong
Published: November 2011

To depend on the development platform of the smart car contest, a smart car servosystem, based on Freescale 16-bit HCS12 micro-controller MC9S12XS128, is designed in this paper. The system uses the low-power CMOS digital camera OV6620 to obtain the real-time track information, and extracts the black line on the contest lane with the edge detection method to calculate the position deviation between the car and the black line, with the purpose of distinguishing the different shape of the lane. The nonlinear PD control algorithm for the steering control was given in this paper. Through the photo electrical encoder named YZ30D4S-2NA-200 to attain the real-time car speed, the system uses the nonlinear P strategy to achieve the speed closed-loop control. It is proved that the servosystem can achieve the automatic line patrol control, so as to make the smart car drive stably and quickly.
Stability Analysis of Single-Track Railway Long Span Combination Bridge of Arch and Beam
Authors: Ji Ri Chen , He Jun , Shi Ming Xing
Published: November 2011

For the single-track railway concrete-filled steel tube tied-arch bridge, since restrictions of the bridge width will inevitably lead to a relatively smaller ratio of width to span using long span.The stability is a very prominent issue in design and construction. Taking a 136m span through concrete filled steel tube tied-arch bridge as an object, considering the influence of geometric and material nonlinearity of arch rib, its space stability analysis of the whole bridge is made using finite element program. Its stability factor and the instabil-ity mode are given under the most unfavourable load condition. Instability of the structure is mainly shown in out-plane instability of arch rib. Elastic buckling factor is greater than the general requirement, which satisfies the requirement of the bridge elastic stability. The effect of geometric nonlinearity on stability of the bridge is smaller while the effect of material nonlinearity is greater, which should be considered in the stability analysis of long span arch bridge. After the arch ribs are progressively loaded, the ultimate loads of the arch ribs are obtained. Effects and variation law of transverse brace layout, arch rib inclination angle and ratio of height to span of the arch to the stability of this bridge are revealed.
Study on Mechanism of Action of Catalysts on Liquefaction of Bagasse Alkali Lignin
Authors: Sui Xin Jin , Wu Shu Bin
Published: November 2011

Bagasse alkali lignin is the primary constituent of pulping black liquor. The phenolic products such as phenol, 2,6-dimethoxy-phenol and 2-methoxy-phenol were obtained by catalytic liquefaction from bagasse alkali lignin, with the aim of enhancing its use value. In the investigation, under optimal conditions, using SiO2-Al2O3 or FeS as catalyst, the phenols yield reached 54.10% and 55.18%, respectively. HPLC spectrum showed that the phenolic products of them were different. FT-IR and H-NMR spectrums showed that, using SiO2-Al2O3 as the catalyst, the α-O-4 and β-O-4 ether bonds and C-Cα bonds of lignin units were prone to break, forming 2,6-dimethoxy-phenol, 2-methoxy-phenol and phenol. While FeS action was more difficult, the α-O-4 and β-O-4 ether bonds and Cα-Cβ bonds of lignin units broke down. Then, the introduction of additional hydroxyl groups from glycols consequently increased the final product solubility. At the same time, Cα–C bond of the phenylpropane linkage was broken to produce phenolic chemicals. Third, part of the phenylpropane linkage was prone to break Cα–Cβ bond and structural rearrangement occurred. So the content of 2-methoxy-4-methyl-phenol and the total yield of phenols were high.
The Location Effecting of the Braces to the Lateral Displace of the Steel Frame Using the Time History Analytical Method
Authors: Gao Dui Xian , Chen Zhi Wei
Published: November 2011

Using the time history analytical method to study the location effecting of the braces to the lateral displace of the steel frame. Base on the really project and the calculation comparing of the example in the time history analysis, the authors discuss the regularity of the location effecting of the braces to the lateral displace of the steel frame and analysis the structure. It can be referred to design in China.
Control Techniques for Uni-Axial Continuous Laser Fabrication
Authors: Yoon Kwang Ho , Kim Kyung Han , Lee Jae Hoon
Published: November 2011

We propose control techniques to extend the fabrication area that is the limit of traditional laser fabrication systems. The current world trend of PCB core technology development is focused on next generation semi-conductor package board and special high value-added PCB including a buildup board. Laser fabrication is necessary when the process microscopic line width and the line over the scanner area and it should be synchronized scanner-stage. This cannot be done with the current Step & Scanning method. To solve this problem synchronization of the stage and scanner was facilitated to continuously process a wide-area. The processing speed and laser fabrication quality were also improved.
Laser Welding Simulations of Stainless Steel Joints Using Finite Element Analysis
Authors: Balasubramanian K.R. , Suthakar T. , Sankaranarayanasamy K. , Buvanashekaran G.
Published: November 2011

Laser beam welding (LBW) is a fusion joining process that uses the energy from a laser beam to melt and subsequently crystallize a metal, resulting in a bond between parts. In this study, finite element method (FEM) is used for predicting the weld bead profile of laser welding butt, lap and T-joints. A three-dimensional finite element model is used to analyze the temperature distribution weld bead shape for different weld configurations produced by the laser welding process. In the model temperature-dependent thermo physical properties of AISI304 stainless steel, effect of latent heat of fusion and convective and radiative boundary conditions are incorporated. The heat input to the FEM model is assumed to be a 3D conical Gaussian heat source. The finite element software SYSWELD is employed to obtain the numerical results. The computed weld bead profiles for butt, lap and T-joints are compared with the experimental profiles and are found to be in agreement.
Effect of Peclet Number on the Thermo Capillary Convection and Molten Pool Shape Formation during Laser Welding Using CFD
Authors: Suthakar T. , Sankaranarayanasamy K. , Balasubramanian K. R. , Buvanashekaran G. , Krishna Murthy K.
Published: November 2011

A mathematical model is developed for the simulation of keyhole and molten pool formation during laser beam welding. Heat transfer from the key hole to the weld pool and details of the fluid flow play a major role in determining the weld bead profile. The simulation is performed based on the control volume method (CVM) and a volumetric heat source is used to model the laser beam and the equations of mass, momentum and energy are solved. The effect of Peclet number, Marangoni number, and Nusselt number is studied by varying process parameters like welding speed and beam power. The simulated bead profiles are compared with the experimental profile and are found to be acceptable.
Growth and Characterization of ZnO Thin Films Grown by Pulsed Laser Deposition
Authors: He Jian Ting , Tan Bo Xue , Wei Qin Qin , Su Yuan Bin , Yang Shu Lian
Published: November 2011

ZnO thin films were deposited on n-Si (111) substrates at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), scanning electron microscopy (SEM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. An optimal crystallized ZnO thin film was observed at the oxygen partial pressure of 6.5Pa. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface components and distribution status of various elments in ZnO thin films. It was found that ZnO thin films were grown in Zn-rich state.
Research on Laser Damage to IR Guidance Anti-Ship Missile Detectors
Authors: Liu Yan Wu
Published: November 2011

Aiming at laser weapon damage to anti-ship missile, laser damage to IR guidance anti-ship missile detectors was researched. First, model on laser weapon damage to IR guidance anti-ship missile detectors was set up. Then 1.06μm and 10.6μm laser atmospheric transmittance on the sea was calculated. Finally, 10.6μm laser was given as an example, the necessary laser energy which can damage effectively the IR guidance anti-ship missile detectors was calculated. Some valuable data and conclusions were gained. It is concluded that laser weapon damage to IR guidance anti-ship missile is feasible at present.
The Analysis of Turntable Error and Arithmetic Design for North-Finder Based on Rate Biased RLG
Authors: Zhang Yan , Cao Ju Liang , Wu Wen Qi , Hu Guo Chang
Published: November 2011

Currently, the continuous rotary north-finder is widely discussed for its outstanding performance. However, few researches on the influence of turntable error to the continuous rotary north-finding algorithm can be found. Turntable errors, such as the stability of rotate speed, the periodic angle measurement error and the discrete angle measurement error, are studied for the north-finder based on rate biased RLG (ring laser gyro). Two north-finding algorithms are designed, which can restrain the influence of angle measurement errors and the stability of rotate speed separately. Finally, simulation and experiments are performed to verify the algorithms.
Planning Strategies for Surface Hardening by Laser Robot
Authors: Liu Li Feng , Yang Xi Chen , Zhang Hai Ming
Published: November 2011

Process planning strategies for surface hardening by laser robot was introduced. It has many characteristics, such as integration, flexibility and environmental protection. According to technology requirement, the path planning and robotic hardening program were accomplished automatically. The FANUC ROBOGUIDE was used to realize simulation. Experiments were carried out to evaluate the application of process planning strategies for laser surface hardening.
Placement Sequence Methodology in Pallet Pattern Formation in Robotic Palletisation
Authors: Khan Hussain Ali , Masood Syed H.
Published: November 2011

The Pallet Loading Problem (PLP) in packaging industry usually deals with generating optimal pallet patterns of placing boxes on a rectangular pallet. For a given pattern, the boxes can be placed in different set of sequences each affecting efficiency and productivity of robotic palletisation. Therefore, getting an optimal pallet pattern does not guarantee an optimal pattern placement strategy. Therefore, there is a need to develop a methodology that considers the palletisers physical characteristics and limitations in robotic palletising systems. This paper presents development of a methodology to determine the placement sequence in robotic pallet pattern formation with the aim of improving the operational efficiency in robotic palletisation.
Fractal Theory’s Investigation in Pneumatic Flocculation Process
Authors: Wang Long , Li Yan , Zhang Qin Qin , Xue Guang Lei
Published: November 2011

Coagulation-sedimentation test at different inflatable combinations, and using microscope to observe the morphological characteristics of flocs. This paper also measured the flocs’ fractal dimension. And analyzed the relationships between fractal dimension and floc characteristics, Coagulation effect
Nonlinear Buckling Analysis of Wind Turbine Towers
Authors: Cao Qing , Li Yang , Zhang Hao
Published: November 2011

Wind turbine towers are belonging to towering cylinder shell structures, which are easy to appear buckling instability under wind or other complicated loads, and on which integral elastic-plastic buckling analyses have great theoretical and practical significances. This paper used large deflection nonlinear pre-buckling and Koiter initial post-buckling theories, and adopted the finite element scheme of updated integration algorithm and LDC nonlinear solution method, then analyzed the linear buckling, elastic-plastic static buckling, and post-buckling response of the towers with initial imperfections in different location and size. It has obtained that: 1) the critical load of towers with elastic-plastic buckling is much smaller than it with elastic buckling; 2) gravity has certain influence on the critical buckling load; 3) the critical buckling load is insensitive to initial imperfections, meanwhile the imperfections which located on the top or the bottom of the tower are inferior for the stability of tower.
Experiment and Simulation on Coarse Slime Recovery by Water Medium Fluidized Separator
Authors: Tan Zhi Hai , He Ya Qun , Lv Yi Bo , Peng De Qiang , Wu Ren Chao , Zhou Guo Ping , Xie Wei Ning
Published: November 2011

A laboratory water medium fluidized separator (WMFS), which is 0.06 m in diameter and 1.5 m high, was designed based on fluidization technique and the principle of hindered settling in hydrodynamics. Then the separation principle of WMFS and the construction of the separation system were introduced. The coarse slime as feed is fluidized by upstream, and is separated according to the different settling velocities (terminal velocities) of the coarse slime in WMFS. The water flow pattern in WMFS was simulated by using CFD software, and the data were analyzed in theory. Finally, the experiment results show that the fluidization technology can be efficiently used in beneficiating coarse slime of -1mm+0.25mm with an Ep value of 0.074.
Development of Islanding Detection Based on Power Controlling for Grid-Connected of Dispersed Power Generation
Authors: Chen Wei Min , Chen Guo Cheng , Cai Hui
Published: November 2011

A novel islanding detection method based on Power Controlling is presented in this paper. The method continuously perturbs the reactive power supplied by dispersed generation systems while simultaneously monitoring the point of commoncoupling (PCC) voltage and frequency. When in grid-connected scenario, the voltage and frequency of PCC is insignificant; however, once the islanding event takes place, the frequency of PCC will be change own to the change of output reactive power. After it is over 4 cycles continuously, then the active power of dispersed generation systems is reduced to 80%, now a drop in voltage positively confirms islanding. Algorithm of the method is simple and confirmed by simulation with MATLAB.
Simulation of Flows Near a Groin in a Straight Open Channel with Effects of Streamline Curvature
Authors: Sun Guang Cai , Wei Wen Li , Liu Y.L. , Rong Gui Wen
Published: November 2011

A mathematical model for predicting turbulence flows with effects of streamline curvature under orthogonal curvilinear coordinates is developed in this paper .The SIMPLEC solution procedure has been used for the transformed governing equations in the transformed domain. The flows near a groin in a straight open channel are employed to test the capability of the proposed turbulence model in capturing the effects of local curvature .The comparison between the computed results and experimental data shows a satisfactory agreement.
An Optimization Model of Noise and Vibration in Passenger Car Cabin
Authors: Junoh Ahmad Kadri , Nopiah Z. M. , Muhamad W. Z. W. , Nor M. J. M. , Fouladi M. H.
Published: November 2011

Car cabin acoustical comfort is one of the factors which attract the buyer prospective buyer on purchasing a new vehicle. Basically the amount of discomfort depends to magnitude, frequency, direction and also the duration of exposed vibration in the cabin. The comfort of the driving influences driving performance. Generally the vibration is caused by two main sources: engine transmission and interaction between tyre and road surface. In this study the effects of vibration to noise in passenger car cabin were investigated. Vehicle acoustical comfort index (VACI) was used to evaluate the noise annoyance level and vibration dose value (VDV) was used to evaluate the vibration level. By referring to the noise and vibration trend to engine speeds, an optimization model was built to find the optimal VDV value against the engine speed in order to obtain required maximum noise (VACI) in the passenger car cabin. Thus, a VACI-VDV reference table formed to assist automotive researchers to reduce the vibration and at the same time to reduce noise annoyance level in passenger car cabin.
Prelimenary Study on Thermomechanical Modelling of Cutting Process
Authors: Hairudin Wan Masrurah Bt , Awang Mokhtar B.
Published: November 2011

In this paper, thermo mechanical modelling of cutting process has been developed using a commercially available finite element analysis software, ABAQUS. A 2-D orthogonal cutting has been modelled using Arbitrary Lagrangian-Eulerian (ALE) formulation. The Johnson-Cook plasticity model has been assumed to describe the material behaviour during the process. This study is aimed at temperature and stresses distributions during machining of AISI 1045 steel with different rake angles; α=0° and α= -10°. The results showed that the maximum stress for 0° and -10° are 963MPa and 967MPa while the maximum temperature results shown that 771°C and 347°C.
Adaptive Aluminum Extrusion Die Design Using Case-Based Reasoning and Artificial Neural Networks
Authors: Butdee Suthep
Published: November 2011

Aluminum extrusion die design involves with two critical parts; die features and its parameters. Presently, die design process is performed by adaptation approach. The previous dies together with their parameters are collected and stored in a database under the well-memory organization. Case-Based Reasoning (CBR) has been applied and enhanced the design productivity. However, the CBR method has an excellent ability only that an exact or similar design features are existed. Reality, aluminum die design requires regularly changed according to the profile changes. Therefore, it needs to predict optimum parameters to assist in the process of aluminum profile extrusion. This paper presents the redesign process using adaptive method. In this case, CBR & ANN method are combined and development. The CBR uses for die feature adaptation; whereas the ANN is used for parameter adaptation and prediction to a new profile and die design. The actual production yield is given and the ANN will find the best size of billet length in order to receive the maximum yield.
The System of the University Experimental Physics Course-Choosing on ASP
Authors: Li Xin , Lu Hai Dong
Published: November 2011

The system provide some convenient to the teaching and administration of academics, and achieves network management in teaching course-choosing. Combining with ASP.NET language is used in client layer, SQL SERVER2000 database is used as the background database. The object oriented C# language is adopted in ASP.NET so that the problems of portability and upgrade are resolved.
Operational Framework for Manufacturing Resource Planning (MRPII) System Case Studies in Malaysian Small and Medium Enterprises a Taxonomy Model for Structural Misfit of MRPII System
Authors: Tan Shiang Yen , Idrus Rosnah , Yusof Umi Kalsom
Published: November 2011

Manufacturing resource planning (MRPII) system which is the core information system that supports the operations of manufacturing organization, are often failed to meet estimated benefits, impeding operational performance and strategic advantages, due to the misfit between the structure modeled in the system and the actual structure of manufacturing environment it intended to represent. Furthermore, disputations upon whether organizational adaptation is always superseding other misfit resolving strategies have increasingly exposed. Hence, this paper presents an operational framework – taxonomy model of MRPII misfit to be applied in a case study which involves three small and medium manufacturing organizations in Malaysia, with the purpose of systematically classify MRPII misfits, and subsequently to identify appropriate misfit resolving strategy (system modification or organization adaptation) based on the specificity of the misfit. The implications of each type of MRPII misfit have been discussed from the perspectives of degree of misfit severity, risk of the MRPII system, organizational discretion on structural change, and most importantly the misfit resolving strategy. In addition, the planned methodology of the case study is presented, in details of selection of case companies and data analysis method. The findings of this proposed study is expected to serve as general guidelines or basics that can be referred by adopting organization to build their resolving strategy, according to the specificity of MRPII misfit situation which they encountered.
Computer Modeling of MWIR Homojunction Photodetector Based on Indium Antimonide
Authors: Nadimi M. , Sadr A.
Published: November 2011

High operating temperatures infrared photodetectors are needed for improving the performance of existing military and civilian infrared systems. To obtain high device performance at higher temperatures, the thermally generated noise required to be reduced. Minority-carrier extraction and exclusion techniques are the approaches for decreasing the thermal noise of infrared systems. In the present work, an InSb extraction diode was studied and simulated for operation in the MWIR region. The simulation was performed using ATLAS device simulator from SILVACO®. The energy band diagram, doping profile, electric field profile, dark current and spectral response were calculated as a function of device thickness, applied reverse voltage and operating wavelength. The simulated photodetector exhibited a zero bias resistance-area product, R0A = 1.6×〖10〗^(-3) Ω〖.cm〗^2 at 240K.
Empirical Process Model for Arsenic Diffusion in Si1-x-yGexCy Alloys
Authors: Sharma Abhishek A. , Telang Santosh V. , Shrivastav Ashish S. , Shetty Saikalash D. , Shetty Shweta U.
Published: November 2011

The thermal diffusion behavior of ion-implanted Arsenic (As) in SiGeC alloy has been investigated and modeled. This paper introduces an empirical model consisting of physics-based and process-based parameters for evaluating the effective diffusivity of Arsenic in SiGeC accurately. The different process parameters that were found to affect the diffusivity were – Germanium content (x), diffusion temperature (T) and Carbon content (y). Germanium content taken into account was 7% and 12.3% for compressive strain in the structure with a Carbon content of 0.2%. The model incorporates all the effects associated with the change in the process parameters which affect the diffusivity of As in compressively strained-Si1-x-yGexCy. The model was found to be extremely accurate in predicting the exact dependencies of As diffusivity on physics-based and process parameters. The proposed empirical process model may find suitable application in the prediction of thermal diffusion behavior of As in Si1-x-yGexCy process-flow as well as in improving the existing model in Silvaco’s TCAD suite.
A Study on Improving in Natural Convection Heat Transfer for Heat Sink of High Power LEDs
Authors: Meng Xiang Rui , Ma Xin Ling , Lu Ji Fu , Wei Xin Li
Published: November 2011

In this paper the natural convection heat transfer performance of horizontal heat sink was studied by numerical simulation and experiment. The numerical simulation results show that there are some interesting features in the flow field of heat sink model. 1) Among the fins, the air vertically flows only through the fins in the symmetry center of heat sink while it horizontally flows through the fins in other area. 2) There is an air stagnation zone located at the fin root in the symmetry center of heat sink. These features both caused the decrease in heat transfer temperature difference and heat transfer area in fact. The natural convection heat transfer performance of heat sink is affected at last. In order to eliminate the air stagnation zone and change in the flow way of air, some holes were perforated at the fin root. These holes play its role. In this test, the heat transfer power of heat sink with seven holes has increased by 16.7% compared with the prototype.With the increase in the number of holes, the natural convection heat transfer power of heat sink also increases. But when the number of holes reaches to a value, the increase in the number of holes will not function properly.
H∞Control for PMLSM Suspension Platform Based on PDFF
Authors: Xia Jia Kuan , Wang Yi Na , Sun Yi Biao
Published: November 2011

Permanent magnet linear synchronous motor (PMLSM) suspension system has the merits of no friction, high-speed, high response and so on, using the normal force achieve the mover suspension. The servo performance is affected by the nonlinear coupling between the horizontal trust and vertical normal force, parameters uncertainties and load disturbances. The feedback linearization method is used to achieve the dynamic decoupling of the PMLSM suspicion system and decoupling it Into two linear subsystems; to solve the conflict between disturbance restraint and fast tracking performance, increase the robustness and dynamic stiffness for system, H∞ speed controller based on PDFF and position proportional controller are designed. Simulation results show that the proposed control strategy guarantees the high speed and high precision positioning performance for horizontal axis; the good rigidity and stability for normal suspension length and the strong robustness against load disturbances and parameters variations for the two axes.
Synchronization Control of Space Voltage Vector Controlled Multi-PMSM Based on Adjacent Cross-Coupling
Authors: Zhang Yong , Deng Hua , Zhang Yi
Published: November 2011

In this paper permanent magnet synchronous motor (PMSM) which is a multi-variable, nonlinear and high coupling system has a good performance adopting the strategy of field-oriented control (FOC) and space vector PWM (SVPWM). Furthermore, multi-PMSM synchronous driving system is established on employing adjacent cross-coupling strategy (ACC). In addition, a variable structure control with an integral sliding surface and exponential reaching law is designed for speed controller. Comparing with traditional PI controlled multi-PMSM system the results illustrate the effectiveness of the proposed control.