• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.5 s.248
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• pp.609-614
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• 2006

Recently linear motor has been used mainly for high speed feeding performance of machine tools. The advantages of linear motor are not only high speed but high accuracy, because it is not required the coupling and ballscrew for converting rotary to liner motion. Before applying in different moving system, the dynamometer is necessary to test the performance. In Korea, the linear motor is producing in a couple of company However, the liner motor dynamometer is not commercialized yet, like as rotary motor dynamometer. In this paper, a linear motor dynamometer is designed and manufactured using a MR damper. The dynamometer system developed in this study could be used for testing the positioning accuracy fur different loading conditions, traction forces, dynamic performance and so on.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.313-317
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• 2005

Precision motor dynamometer is requiring for nano positioning control performance recently. Particularly, linear motor is using rapidly and the dynamometer needs is increasing. In this study, a precision control dynamometer is designed using MR (Magnetic Rheological) damper. The ultra precision motor system including the driver and controller is tested using the MR damper dynamometer. This dynamometer is able to measure torque for rotary motor or traction force with linear positioning accuracy for linear motor system.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.7
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• pp.1060-1067
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• 2009

The authors have proposed a linear motor driven container crane system, in which the linear motor to drive trolley chassis is also used to control swaying motion of a hanging container. To utilize the proposed system, it is needed to develop a power saving control system for the linear drive system. In this paper, an integrated control system to minimize required electric power to drive a trolley chassis with the suppressed swaying motion of a hanged container, is proposed. The validity of the proposed control system is investigated by the simulation using Simulink.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.621-625
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• 1996

The feed system of the machine tools is limited by the mechanical transmission elements. However, thanks to the advanced modern technology, those machines are able to equip with linear motors. In this paper, the types and application aspects of linear motor are discussed and a synchronous type of the linear motors has been applied to X-Y table for machining center. The performance shows an outstanding result in terms of the accuracy, speed and stiffness. Machine tool system with linear motors is expected to be more productive machines using linear motor in the near next years.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.215-224
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• 2008

In this paper, we introduced a linear motor-based transfer system with an active pid controller which can be replaced with an automated guided vehicle (AGV) for the port automation. This system, which is named LMCTS(liner motor-based container transfer system), is based on PMLSM (permanent magnetic linear synchronous motor) which basically consists of stator modules on the rail and shuttle car. Therefore more progressive and adaptive control mechanisms should be required to control a system with large variation of container weight, the difference of each characteristic of stator modules, a stator module's trouble etc. We introduced an active control mechanism with an online tuning scheme using modified evolutionary strategy. Some computer simulations are implemented to assess the robustness of the proposed system.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.553-559
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• 2004

The servo motor is used for the driving power source of the conventional linear conveyor system. The mechanical power transfer system is needed for converting the circular to the linear operation. But this system causes some problems of position error, the necessity of the periodical maintenance. In this paper the study on application of transverse flux linear motor(TFLM) is carried out for the indexer system of LCD processing because TFLM has much thrust per a volume than the conventional motor. TFLM is suitable system for the indexer system because of capacity of acceleration, maximum speed and precision of the position, etc.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.3
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• pp.62-68
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• 2002

To satisfy the requirement of the one axis linear positioning system, which is following control of the desired trajectory without following error and is the high positioning accuracy, feed-forward loop having cogging force model is proposed. In the one axis linear positioning system with linear PM motor, cogging force acting as disturbance is modeled analytically. Analytic model of cogging force is verified by result measured from positioning system constructed with linear PM motor. Measured result is very similar with proposed analytic model. Cogging force model is used as feet forward loop in control scheme of linear positioning system. Cogging force feed-forward'loop is obtained from analytic model of cogging farce. Trajectory following error is reduced from 300nm to 100nm by applying the proposed cogging farce feed-forward loop. By using analytic model of cogging force, the control scheme is simplified. Also this analytic model is applicable to calculation of characteristic value of positioning system in design process.

• Journal of Power Electronics
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• v.5 no.2
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• pp.166-172
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• 2005

The basic equations of a doubly-fed long-stator linear motor for a shuttle-based railway system are established. They show which degrees of freedom exist for controlling the motor. The ratio of stator and rotor current proves to be an important parameter in determining the design of motors, converters and mechanics.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.321-325
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• 2004

Linear motor feed drive systems have been broadly used in machine tools or precision automatic feed systems. Recently, modem machine tools require high speed and high precision feed drive system to achieve high productivity. Unfortunately, a feed drive system, even though it was optimum designed, may experience severe transient vibrations during high-speed operation if its feed rate control is unsuitable. A rough feed rate curve having discontinuity in its acceleration profile causes a serious vibration problem in the feed slides system. This paper presents a feed rate optimization of a machine tool feed slide system, which is driven by a linear motor, for its minimum vibrations. Firstly, a 4-degree-of-freedom lumped parameter model is proposed for the vibration analysis of a linear motor driven machine tool feed drive system. Next, a feed rate optimization of the feed slide is carried out for minimum vibrations. The feed rate curve optimization strategy is to find out the most appropriate acceleration profile with jerk continuity. Of course, the optimized feed rate should approximate to the desired one as possible. A genetic algorithm with variable penalty function was used in this feed rate optimization.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.3
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• pp.183-190
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• 2016

In this study, we conduct linear and nonlinear modeling of the DC motor driving system of a wheeled mobile robot, which is a nonlinear system involving dead zone, friction, and saturation. The DC motor driving system consists of a DC motor, a wheel, and gears. A linear DC motor driving system is modeled using a steady-state response and parameter measurements. A nonlinear DC motor driving model is identified with the use of the Hammerstein-Wiener method. By using these models, PID controllers for the DC motor system are then established. Each PID controller is applied as a low-level controller in order to achieve posture stabilization control for the real mobile robot. We also compare the performance of the proposed PID controllers in posture stabilization experiments by using several different final robot postures.