• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.342-344
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• 2006

전동기 구동시스템의 사양 결정과 설계를 위해서는 부하의 부하토크, 관성계수, 마찰계수 등의 정보에 의한 부하 모델링이 반드시 필요하다. 전동지게차 시스템의 모델링을 위해서는 차체의 중량과, 바퀴의 제원 등 제한적인 정보를 기초로 하여 번거로운 계산과정을 거쳐야 하지만 정확한 정보를 얻기에는 어려움이 따른다. RecurDyn은 기계시스템의 모델링과 시뮬레이션을 하는 3차원 해석이 가능한 Functionbay사에서 개발한 시뮬레이션 프로그램으로서 3D의 기계적인 형상을 작성하고, 물성을 입력하면 부하토크, 등가 관성계수, 마찰계수를 출력할 수 있어 전동기구동시스템의 시뮬레이션 프로그램인 Matlab/Simulink와 결합하여 시뮬레이션을 수행 할 경우 부하 모델링 없이 전체 구동시스템의 특성 시뮬레이션이 가능하다. 본 논문에서는 영구자석 동기전동기로 구동하는 전동지게차 시스템을 대상으로 RecurDyn 프로그램의 활용을 소개하고 Matlab/Simulink를 이용한 결함 시뮬레이션의 가능성을 보고자 한다.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.109-111
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• 2008

전동기 구동시스템의 모델링을 위해서는 부하의 부하토크, 관성계수, 마찰계수 등의 정보에 의한 부하 모델링이 반드시 필요하다. 하지만 기본적인 부하모델의 제정수와 단순화된 운동방정식만으로는 기계적 각 부분에서의 발생하는 현상에 대한 해석이 불가능 하다. 본 논문에서는 엘리베이터 도어 구동시스템을 대상으로 기계 해석 분야의 해석 프로그램인 RecurDyn과 전력전자 분야의 시뮬레이션 프로그램인 Simplorer의 Co-Simulation을 통한 부하 모델 및 구동 시스템의 해석 가능성과 해석 범위를 분석하고 실험을 통해 타당성을 검증하고자 한다.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.91.1-91
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• 2002

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1159-1162
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• 1995

In the continuous process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction plays a major role in the determination of the traction force between the moving web and the rollers. In this paper, a procedure to determine the frcition coefficient between the moving web and rollers is devoloped. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operating web tension and wrap alngle increase.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.301-301
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• 2013

구동형 부품(Actuated component)중의 하나인 LeadScrew는 이송장치를 구성하는 핵심 부품으로 소재로는 탄소강, 합금강, 스테인레스강 등이 주로 이용된다. 다양한 IT기기의 정밀 이송 및 고속 구동에 사용되며, 제품의 성능을 결정하는 중요 핵심 부품으로 사용되고 있다. IT기기용 구동 요소 부품은 정밀 가공성의 제약으로 내식성이 우수한 스테인레스강 소재보다는 일반적으로 소재비가 저렴하고 가공성이 우수한 탄소강 소재를 사용하게 되며, 위 소재를 사용하면 대기중의 수분등에 의한 부식환경에서 쉽게 부식되어 부식방지를 위한 표면처리 기술개발이 필요하다.또한, 구동형 부품은 부품 상호간의 심한 마찰 등과 같은 가혹한 조건에 노출되어, 부품의 내마모성 및 표면 경도등을 향상시켜 부품의 수명을 연장하고자 한다. 그러기 위해 선 표면경도, 내마모성, 내식성 등의 다양한 기능이 요구되며, 성능을 만족시키기 위해서 열표면처리 공정을 확인하고자 한다.본 연구에서는 냉간압조용 강선인 SWCH계열 표면에 PECVD 장치로 플라즈마 질화공정을 이용하여 동일조건(압력, Gas flow, Power)하에서 $500{\sim}550^{\circ}C$의 온도 범위 내에서 30~300 min의 시간 조건으로 실험을 진행하였다. 위 시험편으로 XRD를 통해 각 플라즈마 질화 공정 조건에 따른 상 변화를 확인하였고, 염수분무테스트를 통해 내식성을 확인하였다. 표면경도 및 단면경도를 통한 실용질화층을 확인하고, 마모테스트를 통하여 마찰계수를 확인하여 표면경도, 내마모성, 내식성을 충족하는 공정에 대한 실험을 진행하였다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.5
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• pp.53-58
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• 2003

Wear debris can be collected from the lubricants of operating machinery and its morphology is directly related to the fiction condition of the interacting materials from which the wear particles originated in lubricated machinery. But in order to predict and estimate working conditions, it is need to analyze the shape characteristics of wear debris and to identify. Therefore, if the shape characteristics of wear debris is identified by computer image analysis and the neural network, The four parameter (50% volumetric diameter, aspect, roundness and reflectivity) of wear debris are used as inputs to the network and learned the friction. It is shown that identification results depend on the ranges of these shape parameters learned. The three kinds of the wear debris had a different pattern characteristic and recognized the friction condition and materials very well by neural network. We resented how the neural network recognize wear debris on driving condition.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1542-1547
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• 2003

Air entrainment can become a significant problem in a web handling process. The development of air film between a web and an idle roller can cause a reduction of traction and traction coefficient, by which a slip is occurrred. Computational and experimental study was carried out to describe the slippage of an idle roller for given operating conditions, tension and web velocity. An extended mathematical model to find out a slip condition was developed by using the models of air film height, dynamic traction coefficient, and torque balance of a rotational roller. And by using the extended model, a mechanism to define the slippage between the roller and the moving web was suggested. The results of simulation and experiment showed that the extended dynamic model could properly characterize the rotational motion of the idle roller by considering dynamic traction coefficient. By examining the rotational motion of the idle roller with web dynamics(speed), the mechanism to define al slip condition between the roller and the web was found to be effective.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.512-519
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• 2016

In this study, the tire road friction estimation(TRFE) algorithm for controlling the rear wheel driving force of a 4WD vehicle during acceleration is developed using a standard sensor in an ordinary 4WD passenger car and a speed sensor. The algorithm is constructed for the wheel shaft torque, longitudinal tire force, vertical tire force and maximum tire road friction estimation. The estimation results of shaft torque and tire force were validated using a torque sensor and wheel force transducer. In the algorithm, the current road friction is defined as the proportion calculated between longitudinal and vertical tire force. Slip slop methods using current road friction and slip ratio are applied to estimate the road friction coefficient. Based on this study's results, the traction performance, fuel consumption and drive shaft strength performance of a 4WD vehicle are improved by applying the tire road friction estimation algorithm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.346-350
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• 1996

In optical disk drives, one of commonly used pickup actuator is a Sliding and rotary type of pickup actuator which is cheaper than other pickup actuators and has simple assembly. However, it reported that non-linearity due to friction between a shaft and a sleeve had to be considerably analyzed in design and servo system in employing this type of pickup actuator. In this paper, this friction is modeled as a Coulomb's friction and the effect of friction is examined in the simulation. A digital servo system is applied to pickup actuator with friction in order to have good focusing servo. To enhance focusing servo performance using digital servo merit, frist PD-controller is applied to have fast response performance, second lead-lag compensator is applied to have stable focusing performance.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.5
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• pp.165-170
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• 2001

In the continuos process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, winding, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction play major role in the determination of the traction force between the moving web and the rollers. In this paper the characteristics of friction between the moving web and the rollers are studied. A procedure to determine the friction coefficient between the moving web and rollers is developed. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operation web tension increase.