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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
Editor in Chief :
Volume & Issues
Volume 17, Issue 12 - Dec 2000
Volume 17, Issue 11 - Nov 2000
Volume 17, Issue 10 - Oct 2000
Volume 17, Issue 9 - Sep 2000
Volume 17, Issue 8 - Aug 2000
Volume 17, Issue 7 - Jul 2000
Volume 17, Issue 6 - Jun 2000
Volume 17, Issue 5 - May 2000
Volume 17, Issue 4 - Apr 2000
Volume 17, Issue 3 - Mar 2000
Volume 17, Issue 2 - Feb 2000
Volume 17, Issue 1 - Jan 2000
Selecting the target year
Ultraprecision Positioning Technology
Lee, Chan-Hong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 9~15
Actuators for Precision Mechanism and Milli Structure
Kim, Su-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 16~19
Positioning Technology by Linear Motor
Eun, In-Ung ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 20~25
Precision Positioning Technologies with Ballscrew
Park, Cheon-Hong ; Lee, Hu-Sang ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 26~33
Positional Error Compensation Technology for Precise Feed-Drive System
Jeong, Jae-Il ; Kim, Hong-Seok ; Kim, Jong-Won ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 34~40
A Study on the Inveres Kinematic Analysis of a Casing Oscillator
Lee, Eun-Jun ; Bae, Jae-Man ; Park, Myeong-Gwan ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 47~53
The casing oscillator is a construction equipment to clamp, oscillate and push a casing for foundation work. In case that the casing oscillator is operated on the slant ground, if another construction heavy equipment is not used, it is impossible to insert the casing in ground using only casing oscillator. So in this paper, we present the new casing oscillator that need not to level the ground for work of casing insertion. This mechanism can execute 4 DOF motion by actuating 5 single - rod hydraulic cylinders. The inverse kinematics analysis of the casing oscillator is performed and we verify the validity of kinematics analysis through the experiment.
Research about Tool Wear Monitoring in CNC Lathe Machining
Go, Jeong-Han ; Kim, Yeong-Tae ; Lee, Sang-Jo ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 54~60
Research about tool condition monitoring has been done until now for product automation and unmaned system. But it is hard to apply it to the industrial field due to its cost and reliability. This paper presents the new method of tool wear measurement using Marpos gauge. This is a kind of touch sensor, so its cost is lower than vision system. And it is not affected by dust and illumination, which are important in vision system. This proposed method use tool clearance angle to measure flank wear. Experimental results compared with vision system shows that this method is available for tool condition monitoring system.
High Performance On Off Angle Control of SRM Using Linear Encoder
Lee, Yeong-Jin ; Park, Seong-Jun ; Park, Han-Ung ; Lee, Man-Hyeong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 61~67
In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore the rotor position information is an essential. Usually optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. In general, the accuracy of the switching angle is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, which are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper. It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.
The Comparison of Cutting Characteristics of PCD and MCD Tools in the Ultraprecision Turning of Aluminum Alloy
Kim, Hyeong-Cheol ; Ham, Seung-Deok ; Hong, U-Pyo ; Park, Yeong-U ; Kim, Gi-Su ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 68~75
This paper presents the construction of an ultra-precision machining system and machining experiments using the developed system. The system is composed of air bearing system, granite bed, air pad, and linear feeding mechanism. The cutting conditions have great effect on the surface quality in ultra-precision machining. the ultra-precision machining is mainly processed by several
depth of cut and feed rate. For this, tools with sharper cutting edge and less tool wear are needed. To satisfy these requirement, diamond is generally used as a tool material for ultra-precision machining. In order to evaluate the cutting characteristics of the PCD and MCD tools on the aluminum alloy, the machining experiments performed using the developed system.
Analysis on the Fracture of a Panel Glass in a Liquid Crystal Display Module under Mechanical Shock
Park, Sang-Hu ; Lee, Bu-Yun ; Eom, Yun-Yong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 76~81
Analysis on failure of the panel glass under mechanical shock is the main topic of this study. Since the glass for the LCD panel is thin, it needs to be designed to have enough toughness against mechanical shock. In this paper, a process of estimating fracture of the panel glass is proposed to guarantee reliability of the product. The fracture toughness of the panel glass is used as a criterion of the fracture based on an experimental approach. The stress intensity factor was calculated considering a model with the largest initial crack size on a cut surface and with the boundary force obtained from a dynamic finite element analysis. Critical surface roughness on the cut surface of a typical glass panel, to prevent fracture in case of bending mode, is obtained.
Monitoring of Grinding Wheel Wear Using Laser Scanning Micrometer
Ju, Gwang-Hun ; Kim, Hyeon-Su ; Hong, Seong-Uk ; Park, Cheon-Hong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 82~87
This paper deals with monitoring of grinding wheel wear in grinding process. A monitoring system is developed in which a laser scanning micrometer is used to measure the circumferential shape as well as the axial shape of grinding wheel. The monitoring system is applied to grinding machines. The experiment results show that the monitoring system is useful not only for monitoring the amount of wear in grinding wheel but also for measuring the apparent diameter of the grinding wheel.
A Study on the Cushion Package Design of a Monitor using Finite Element Method
H.B.L. ; Park, Sang-Hu ; Kim, Won-Jin ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 88~93
The reduction of the cushion material such as Expanded Polystyrene (EPS) is one of the urgent tasks of the package design process in home electrical appliances considering environmental protection. EPS reduction often causes the structural damage of products, which must be protected in the environment of transportation. CAE simulation can help the efficient package design with low material cost. The mechanical drop simulation of packaged product was performed with commercial FEM code and Taguchi approach was used partially to determine the dominant design parameters. As results of this study, about 20% reduction of EPS was accomplished in the monitor package design.
A study on the In-Process Monitoring of Tool Wear via Ultrasonic Sensor
Jeong, Ui-Sik ; Hwang, Jun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 94~100
This paper presents a methodology for In-Process monitoring of tool wear by using ultrasonic sensor in turning operation. An integrated single ultrasonic transducer operation at a frequency of 10MHz is placed in contact with the insert tip. The change in amount of the reflected energy from the nose and flank of the tool can be related to the level of tool wear and the mechanical integrity of the tool. As the results, the tool wear monitoring system based on the ultrasonic pulse-echo method was proposed, it is useful to determine a tool life and tool change time.
Developing Microcellular Foamed Vibration Isolator for DVD by Axiomatic Approach
Jeong, Pil-Jung ; Cha, Seong-Un ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 101~106
As the rotational speed of optical disk drive is increasing nowadays, the reliability to vibration and shock becomes more important. For this, various of rubber vibration isolators are being developed by varying the shape and hardness. But it is difficult for the hardness of common used rubber to be lowered below Duro 30 degrees, and because of the shape complexity of rubber vibration isolator there are difficulties of analysis. Microcellular foamed vibration isolator has various cell densities and cell sizes, so it can vary the stiffness and damping coefficient. In addition, its hardness can be lowered below Duro 30 degrees. Axiomatic Approach is very useful design method for designing new product or new process. Axiomatic Approach's character is scientific and analytical method. In this paper, developing process of microcellular foamed vibration isolator for DVD is presented with Axiomatic Approach.
A Study on the Fault Diagnosis of Roller-Shape Using Frequency-Domain Analysis of Tension Signals
Sin, Gi-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 107~114
Rollers and rolls in the continuous process systems are noes of key components that determine the quality of web products. The condition of rollers and rolls(ex. eccentricity wear) should be consistently monitored in order to maintain the process conditions (ex. tension, edge position) within a required specification. In this paper, a new diagnosis technique is suggested to detect the defect of rollers/rolls (ex. eccentricity, wear) based on frequency domain analysis of web tension signal. The kernel of this technique is to use the spectrum amplitude of tension signal which allows to identify the fault rollers/rolls and to also diagnose the degree of fault in corresponding rollers and rolls. The experimental results proved that the suggested diagnosis technique can be successfully used to identify the defect rollers and rolls as well as to diagnose the degree of the defect of those rollers. The suggested technique can be applied to monitor and diagnose the shape of rollers and rolls in various multi-span web transport systems.
NURBS Interpolation Algorithm for CNC Machines
Hong, Won-Pyo ; Yang, Min-Yang ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 115~120
Increasing demands on precision machining of free-form surface have necessitated that the tool to move not only position error as small as possible, but also with smoothly varying feedrates. This paper presents new algorithm for high precision 3D(3-dimensional) NURBS(Non-Uniform Rational B-Spline) interpolation in the reference-pulse technique. Based o the minimum path error strategy, interpolation algorithm was designed to follow the NURBS curve. Using this algorithm a real-time 3D NURBS interpolator was developed in software. The algorithm implemented in a PC showed promising results in interpolation error and speed performance. It is expected that this can be applied to the CNC systems for the high precision machining of complex shapes.
Development of the Numerical Procedures for the Control of Linear Periodic Systems
Jo, Jang-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 121~128
The scope of this paper is focused to the systems which have the time period and they should be necessarily studied in the sense of stability and design method of controller to stabilize the orignal unstable systems. In general, the time periodic systems or the systems having same motions during certain time interval are easily found in rotating motion device, i.e., satellite or helicopter and widely used in factory automation systems. The characteristics of the selected dynamic systems are analyzed with the new stability concept and stabilization control method based on Lyapunov direct method. The new method from Lyapunov stability criteria which satisfies the energy convergence is studied with linear algebraic method. And the numerical procedures are developed with computational programming method to apply to the practical linear periodic systems. The results from this paper demonstrate the usefulness in analysis of the asymptotic stability and stabilization of the unstable linear periodic system by using the developed simulation procedures.
Axial Impact Collapse Analysis on Hat-shaped Members by FEM
Cha, Cheon-Seok ; Gang, Jong-Yeop ; Yang, In-Yeong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 129~136
In the frontal collision the spot welded hat-shaped section side member is the fundamental structure for automobiles and has a great amount of absorbing capacity. For this reason LS-DYNA3D has been used for analyzing impact collapse characteristics on hat shaped section member with respect to the valuables; thickness, width ratio and spot weld potch on impact load(7.19m/sec, 1034J). By comparing the results from simulation and the experimental results, the utilization of simulation has been certified.
Finite Element Analysis on the Motion Accuracy of Hydrostatic Table(1.st. Analysis and Experimental Verification on Single-side Table)
Park, Cheon-Hong ; Jeong, Jae-Hun ; Lee, Hu-Sang ; Kim, Su-Tae ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 137~144
In order to achieve systematical method for improving motion accuracy of hydrostatic table, an algorithm using finite element method is proposed in this paper. Quantification of averaging effect of oil film on motion error is performed theoretically by analysis on the relationship between spacial frequency of rail form error and motion error of table. Influences of film stiffness and pocket size on the motion error of table are also analyzed theoretically. Validity of the algorithm is verified experimentally from the test on the motion error of table with three types of rail which have different form profile. Experimental results show that the algorithm is very effective to analyze theoretically the motion error of hydrostatic table.
Study on the Fabrication of Ultrathin Punch
Im, Hyeong-Jun ; Im, Yeong-Mo ; Kim, Su-Hyeon ; Gwak, Yun-Geun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 145~150
Micro punching is one of general methods to fabricate simple holes such as permanent ink-jet printer nozzles. A thin punch, that is need for micro punching, usually has been obtained by mechanical machining. There are some method to obtain a thin punch from a cylindrical rod, e.g., microgrinding and WEDG (Wire Electro-Discharge Grinding). Inefficiently, only one punch can be obtained from these machining methods. In contrast with these methods, many punches can be fabricated simultaneously by electrochemical process. Electrochemical process has usually aimed to obtain very sharp probe for atomic force microscopy (AFM) or scanning tunneling microscopy (STM), and it has not been considered the whole shape of a probe in spite of good merits. In this paper, an ultrathin punch with a tapered shape and a cylindrical tip is newly fabricated by electrochemical process.
A Study on the Stability of the Flywheel System During the Storage and Generation of Energy
Jang, Ung-Jae ; Lee, Su-Hun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 151~156
A vibration in a high-speed machine may lead to machinery malfunction and even catastrophic failure. So solving the vibration problem is a fundamental requirement for the stability of the high-speed machine. The flywheel energy storage system using superconducting magnetic bearings is a device to store electrical energy as rotational kinetic energy by motor and to convert it to electrical by generator when necessary. The high-speed rotating flywheel has large amplitude at a critical speed. And it has an unstable behavior by the electric torque at the first stage of the energy generation. In this paper, the stability analysis is performed with an analytical model and equations of motion-which is considered the effect of the electric torque-to identify the stable driving condition and the dynamic behavior.
Development of Integrity Assessment System for the Pipeline
Lee, Eok-Seop ; Hwang, In-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 157~162
The object of this work is to develop an assessment system for pipeline integrity. the system consists of four module applications for internal algorithm; the effect of corrosion in pipeline, crack, stress corrosion crack (SCC) and fatigue modules. Presently, the module of the external corrosion has been developed and the internal algorithm for the effect of corrosion in pipeline and the database of the system are described in this paper. The database of the system is separated to mainly four parts; geometry of pipeline, material properties, boundary conditions and general properties. Each components of the system are designed by user-friendly concept. This system may give a guideline for maintenance and modifications for the pipeline at the industrial sight. Furthermore, a procedure to evaluate an inspection interval is also provided.
Mechanistic Analysis Modeling for the 3-D Chip Formation Process
Kim, Gyeong-U ; Kim, U-Sun ; Kim, Dong-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 163~168
Once the chip has developed a mixed mode of side-curl and up-curl, it would generally curl to strike the tool flank. The development of the bending stresses and sheat in the chip would ultimately lead to chip failure. This paper approach this problem from a mechanics-based approach, by treating the chip as a 3-D elastic curved beam, and applying appropriate constraints and forces. The expressions for bending, shear and direct stresses are developed through an energy-based criterion. The location of the maximum stresses is also identified and explained for simulated test conditions.
Development of the Pneumatic Manipulator of Gait Rehabilitation Robot using Fuzzy Control
Kim, Seung-Ho ; Jeong, Seung-Ho ; Ryu, Du-Hyeon ; Jo, Gang-Hui ; Kim, Bong-Ok ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 169~175
Stable and comfortable walking supports, which can reduce the body weight load partially, are needed for the recovering patients from neurologic disease and orthopedic procedures. In this paper, the development of a manipulator of rehabilitation robot for the patients with walking disabilities are studied. A force controller using pneumatic actuators is designed and implemented to the human friendly rehabilitation robot considering the safety of patients, reliability of the system, effectiveness of the unloading control and economic maintenance of the system. The mechanism of the unloading manipulator is devised to improve the sensibility for the movement of the patients such as direction and velocity. For the unloading force control, fuzzy control algorithm is adopted to reduce the partial body weight and suppress the unwanted fluctuation of the body weight load to the weak legs due to the unnatural working of the patients with walking disabilities. The effectiveness of the force control is experimentally demonstrated.
A Design of Model-Following Time Delay Controller with Modified Error Feedback Controller
Park, Byung-Suk ; Yoon, Ji-Sup ; Kang, E-Sok ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 176~184
TDC(Time Delay Control) deals with the time-varying system parameters, unknown dynamics and unexpected disturbances using time delay. TDC can be divided into two separate parts: an auxiliary controller and a servo controller. The two controllers can be designed independently. The auxiliary controller is used to reduce sensitivity to parameter variations, nonlinear effects, and other disturbances. The servo controller is to reduce the error between the desired command and output. We propose the model-following time delay controller with modified error feedback controller. This was applied to follow the desired reference model for the uncertain time-varying overhead crane. The model generates the damped-out swinging motion trajectory to suppress the swinging motion caused by the acceleration and the deceleration of crane transportation. The control performance was evaluated through simulations. The theoretical results indicate that this control method shows excellent performance to an overhead crane with the uncertain time-varying parameters.
Investigation of Cutting Characteristics of Linear Hotwire Cutting System and Bonding Characteristics of Expandable Polystyrene Foam for Variable Lamination Manufacturing(VLM) Process
Ahn, Dong-Gyu ; Lee, Sang-Ho ; Yang, Dong-Yol ; Shin, Bo-Sung ; Lee, Yong-Il ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 185~194
Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stacking, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain of RP apparatus. The objective of this study is to develop a new RP process, Variable Lamination Manufacturing using linear hotwire cutting technique and expandable polystyrene foam sheet as part material(VLM-S), and to investigate characteristics of part material, cutting characteristics by using linear hotwire cutting system and bonding. Experiments were carried out to investigate mechanical properties of part material such as anisotropy and directional tensile strength. In order to obtain optimal dimensional accuracy, surface roughness, and reduced cutting time, addition experiments were performed to find the relationship between cutting speed and cutting offset of hotwire, and heat generation of hotwire per unit length. So, adhesion strength tests according to ASTM test procedure showed that delamination did not occur at bonded area. Based on the data, a clover-shape was fabricated using unit shape part(USP) it is generated hotwire cutting. The results of present study have been reflected on the enhancement of the VLM-S process and apparatus.
Residual Stress Measurement of Micro Gold Electroplated Structure
Baek, Chang-Wook ; Ahn, Yoo-Min ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 195~200
In order to find a residual stress in the micro-machined beam, first natural frequency of the beam that has the residual stress inside is analyzed using the Rayleigh's energy method. Micro gold electroplated structure is fabricated by surface micro-machining process. The made structure is clamped-clamped beam and its 1st natural frequency is measured by resonance method. For the better estimation of the residual stress, an equivalent length of micro-machined beam to ideal beam is calculated by FEM. The residual stress is estimated from the equivalent length and the measured natural frequency.
Free Vibration Analysis of Thermoelastic Structure
Cho, Hee-Keun ; Park, Young-Won ; Park, Ki-Young ; Lee, Kyoung-Don ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 201~208
A numerical analysis algorithm for thermally loaded structures has been proposed and compared with the general free vibration approach to determine the characteristics of thermal load effects in vibration structures. The field of numerical inspection includes free vibration analysis, transient heat transfer analysis and thermal stress analysis. The key point of the analysis of thermally loaded structure is the method of parallel time integration between transient heat transfer and free vibration simultaneously. The results of the study demonstrate the computation of the specific total external force vector and stiffness matrix. The proposed analysis method can be applied to both heated and cooled structure vibration analysis.
A study on the lateral Dynamics of the Moving Web Induced by a Tilted Roller
Shin, Kee-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 12, 2000, Pages 209~216
The lateral behavior of the moving web is critical to the quality of the web products. The alignment of the rollers carrying the web is found to be one of important factors to the lateral behavior of the moving web. But, the study on the effect of the tilting roller in the direction of the normal to the moving web on the lateral behavior has not been reported in the literature yet. For example, the contact roller often contacts the winding roll in a tilted fashion and causes the lateral motion of the winding web, which induces the offset on the wound roll. The lateral dynamics of the moving web induced by a tilted roller in normal direction of a web is investigated in this paper. The two-dimensional dynamic model developed by Shelton is extended to investigate the effect of a titled roller in a normal direction of the moving web on the lateral motion of the moving web. New boundary conditions are developed to solve the extended model. Computer simulation study proved that the model developed can be used to predict the lateral motion of the moving web ？ to a tilted roller in normal direction of the moving web. The lateral deflection is increased exponentially a the tilting angle is increased. As the length of web span is increased, the amount of lateral deflection was increased almost linearly for the same tilting angle. The lateral dynamics turned out to be almost independent to the operating tension. The model developed can be used to solve the offset problem of the staggered winding and also to design a new web guiding mechanism.