유도가열에서 강판의 온도 및 변형해석에 관한 연구

배강열 진주산업대학교 산업과학기술연구소 2007 산업과학기술연구소보 Vol.- No.14

In order to control deformation in steel forming with heating process, the electro-magnetic induction process has been utilizing to substitute the flame heating process. However, few studies have been performed to exactly analyze the deformation mechanism of the heating process with mathematical model. This is mainly due to the difficulty of modeling the inductor travelling on plate during the process. In this study, heat flux distribution of the process is firstly numerically analysed with the assumption that the process has a quasi-stationary state and also with the consideration that the heat source itself highly depends on the temperature of base plate. With the heat flux, the thermal and deformation analyses are then performed with a commercial program for a combination of heating parameters. The results are well compared with those of experiment.

바퀴구조를 가진 자율주행 대차의 운동해석

배강열 진주산업대학교 2000 산업과학기술연구소보 Vol.- No.7

A transfer carriage consisted of two driving wheels and one steering wheel is proposed. By neglecting wheel sleep and though analysing kinematics of the carriage, nonholonomic constraints are derived and introduced into the equation of motion derived from Lagrange formulation. A fuzzy and feed-back tracking control technique is also proposed for a motion control of the carriage. The tracking controller based on a feed-back control technique guaranteed the carriage followed the desired trajectory. The fuzzy control technique could deal with unmodeled dynamics such as a change of pay load and compensated the dynamics of the vehicle. The results of computer simulation are presented to illustrate the tracking ability of the proposed system and controller under an initial orientation and position error. The results revealed that a deviation of position error in a load change of the carriage could be much reduced with the fuzzy controller by an appropriate limitation of torques.

거리계측을 위한 시각센서의 설계에 관한 연구

배강열 진주산업대학교 2000 論文集 Vol.39 No.-

A visual sensor consisted of polygonal mirror, laser, and CCD camera was proposed to measure the distance to a 3-dimensional object. To scan the laser light of the sensor onto an object, 8-facet polygonal mirror was used as the rotating mirror. By locating the laser and the camera at axi-symmetrical positions around the mirror, the synchronized-scan condition could be satisfied even when the mirror was set to rotate through one direction continuously, which could remove the inertia effect of the conventional oscillating-mirror methods. The mathematical modelling of the proposed sensor with the optical triangulation method made it possible to derive the relation between the position of an image on the camera and the one of a laser light on the object. By using the derived relation, the field of view and the resolution of the sensor could be also calculated. Through the geometrical simulation of the proposed sensor with the principal of reflection and virtual image, the optical path of a laser light could be predicted. The position and direction of the CCD camera were determined based on the Scheimpflug's condition to fit the focus of any image reflected from an object within the field of view. The results of modelling and simulation revealed that the proposed visual sensor could be used to recognize 3-dimensional objects and also used to measure distance to the objects within the range of the field of view and the resolution.

Design of a non-circular planetary-gear-train system to generate an optimal trajectory in a rice transplanter

Bae, Kang-Yul,Yang, Young-Soo Taylor Francis 2007 Journal of engineering design Vol.18 No.4

<P> The transplanting accuracy of a rice transplanter for picking, conveying and transplanting seedlings mainly depends on the trajectory as well as the return motion of the hoe. The trajectory of the hoe has to be optimized in treating seedlings for a prevailing soil condition. For better transplanting accuracy, a planetary-gear-train system, instead of the four-bar linkage system is used to design a transplanting mechanism. This study proposes a theoretical design method for a transplanting mechanism; the method designs non-circular gears of a planetary-gear-train system for the hoe to trace a prescribed trajectory. An optimization method was used to determine the arm length and tool length; inverse kinematics to determine the configuration angles of the two links and the roll contact condition in transmitting motion between the gears; and a linearization approach to obtain the shapes of the gears. Based on the proposed method, the shapes of the gears and the lengths of the tools of the planetary-gear-train system are determined for three prescribed trajectories. A commercialized package program (ADAMS) is used to carry out a kinematic simulation to confirm that the gear-train system configured from the proposed method is adequate for the transplanting mechanism.</P>

Analysis of magnetic field distribution in a cylindrical-type magnetron sputtering system

Bae, Kang-Yul,Yang, Young-Soo,Choi, Bum-Ho SAGE Publications 2013 PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGIN Vol.227 No.6

<P>The magnetic field distribution in magnetron sputtering processes has been verified to influence the collision of positive ions on the target, as well as the efficiency of the deposition onto the substrate. However, locally concentrated collision due to the distribution has also been known to lead to nonuniform erosion on the target, which deteriorates the efficiency of sputtering. In this study, a cylindrical magnetron sputtering system with a rotary-type target is proposed to improve the expected lifetime of the target by reducing the local erosion of target in the magnetron sputtering process. For the sputtering system, the magnetic field distribution over the target was analyzed with finite element method. Based on the analysis, the effect of the configuration of permanent magnets on the magnetic field distribution was investigated. The result of the analysis could be used to predict the region where concentration of positive ions occurs and thus to estimate the pattern of how the erosion on the target surface would occur for the proposed system. The results also reveal that the magnetic field distribution related to the erosion pattern could be controlled with the configuration of the permanent magnets.</P>

비원형 유성기어열을 사용한 이앙기 식부기구의 설계

배강열(Kang Yul Bae) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.12

Transplanting accuracy of a rice transplanter mainly depends on the trajectory of the hoe for picking, conveying and transplanting of seedlings as well as the return motion. The trajectory can be decided and prescribed to be suitable in treating seedlings for a prevailing soil condition. For the purpose of the transplanting accuracy, the design of a transplanting mechanism would be carried out using a planetary-gear-train system instead of the four bar linkage system. In this study, a design method of transplanting mechanism is theoretically proposed by synthesizing a noncircular planetary-gear-train system for the tool (hoe) to trace a prescribed trajectory. The method utilizes an optimization approach to decide the lengths of an arm and a tool, the inverse kinematics to figure out the configuration angles of the two links, the roll contact condition in transmitting motion between the gears, and a linearization approach to obtain the shapes of the gears. Based on the proposed method, the shapes of the gears and the lengths of the tools of the planetary-gear-train system are determined for three prescribed trajectories. A kinematical simulation with a commercialized package program is also carried out to confirm that the gear-train system synthesized with the proposed method is able to trace the prescribed trajectory.

2상 4/3 SRM의 구조적 특성에 관한 연구

배강열(Kang-Yul Bae),오석규(Seok-Gyu Oh) 한국조명·전기설비학회 2014 조명·전기설비학회논문지 Vol.28 No.5

The intrinsic simplicity, ruggedness, and simple power electronic drive requirement of a Switched Reluctance Motor(SRM) make it possible to use in many commercial adjustable speed application. The simple magnetic circuit results in a high efficiency drive and low temperature rise, and the drive system provides a good drive characteristics. This paper is provides two phase 4/3 SRM that is similar to two phase 6/3 SRM as aspect to magnetic structure. Although 6/3 SRM does not experience any flux reversal as the flux is in the same direction whether phase A or B is excited, but two phase 4/3 SRM experiences a flux reversal in small part of stator yoke. The flux reversal in two phase 4/3 SRM could be relieved by an adjustment of stator yoke structure. The magnetic analysis and design considerations of the two phase 4/3 SRM have been obtained by the finite element method analysis (FEM).

차량용 헬리컬기어의 침탄 열처리 변형해석

배강열(Kang Yul Bae),양영수(Young Soo Yang),박병옥(Byung Ok Park) Korean Society for Precision Engineering 2010 한국정밀공학회지 Vol.27 No.11

Heat treatment with carburized quenching process is widely used for automotive helical gear to improve its surface properties of hardness and strength. However, the gear can be deformed with the process over the allowable tolerance, which possibly makes noise, vibration and heat problems in operation. In this study, deformation of helical gear during heat treatment of carburized quenching was analyzed with a numerical method, incorporating coupled calculations of thermal conduction, carbon diffusion, phase transformation and thermal stresses. With the analysis, the effect of coolant temperature in quenching on the deformation was investigated. The result of the analysis revealed that the higher the coolant temperature became, the more change of helix angle and the more compressive stresses in the surface generated, because of delayed generation of martensite in the part.

A Study on Development of Torch Rotating Mechanism for Automation of Welding of Corrugated Membranes

배강열(Kang Yul Bae) Korean Society for Precision Engineering 2015 한국정밀공학회지 Vol.32 No.3

In order to develop an automatic system for welding thin steel plates with curvature such as the corrugated membranes of an LNG storage tank, a rotating mechanism should be firstly designed for the torch to easily follow the weld seam with a constant distance and angle. In this study, a torch rotating mechanism consisting of three circular links, two square-type links and a torch link was proposed for automation of the welding process. A weld-seam tracking system with two axis slides and the proposed rotating mechanism was successfully simulated with a dynamic simulation software. A prototype tracking system was manufactured and a tracking test with the system was then carried out. The test results with tracking system showed that the rotating mechanism could be implemented and it was feasible to be used in automatic tracking of weld seam with curvature.

자기구성 퍼지제어기를 이용한 이동로봇의 구동제어

배강열(Kang Yul Bae) Korean Society for Precision Engineering 2006 한국정밀공학회지 Vol.23 No.12

A robust motion controller based on self-organizing fuzzy control (SOFC) and feed-back tracking control technique is proposed for a two-wheel driven mobile robot. The feed-back control technique of the controller guarantees the robot follows a desired trajectory. The SOFC technique of the controller deals with unmodelled dynamics of the vehicle and uncertainties. The computer simulations are carried out to verify the tracking ability of the proposed controller with various driving situations. The results of the simulations reveal the effectiveness and stability of the proposed controller to compensate the unmodelled dynamics and uncertainties.