• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.980-981
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• 2008

Mechanical spring and hydraulic pressure operated mechanisms are applied in most of today's High Voltage Gas Insulated Switchgear(GIS)s. This paper proposes a new type of operation mechanism for GIS circuit breakers rated at 245kV and 40kA. The Motor-Direct-Drive-Mechanism (MDDM) has many advantages compared to conventional operating mechanisms. It has a very simple structure with only one moving part, low mechanical stress and audible noise. It also allows monitoring, operation speed control and self-diagnosis functions.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.79-81
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• 2002

This paper develops a adaptive fuzzy controller based fuzzy logic control for high performance speed controller in permanent magnet synchronous motor(PMSM) drives. In the proposed system, fuzzy control is used to implement the direct controller as well as the adaptation mechanism. The operation of the direct fuzzy controller and the fuzzy logic based adaptation mechanism is studied. A model reference adaptive scheme is proposed in which the adaptation mechanism is executed by fuzzy logic based on the error and change of error measured between the motor speed and output of a reference model. The control performance of the adaptive fuzzy controller is evaluated by simulation for various operating conditions. The validity of the proposed adaptive fuzzy controller is confirmed by performance results for PMSM drive system.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.114-116
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• 2007

Mechanical spring and hydraulic pressure operated mechanisms are applied in most of today's High Voltage Gas Insulated Switchgear(GIS)s. This paper proposes a new type of operation mechanism for GIS circuit breakers rated at 245kV and 40kA. The Motor-Direct-Drive-Mechanism (MDDM) has many advantages compared to conventional operating mechanisms. It has a very simple structure with only one moving part, low mechanical stress and audible noise. It also allows monitoring, operation speed control and self-diagnosis functions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.262-267
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• 2012

For DACS system which controls pintle position to change nozzle throat area, one actuator has been used for each modulatable pintle thruster. This ten actuator system drove to complex system structure and complicated control mechanism. In order to overcome this shortcomings, international patents were reviewed, analysed and presented.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.245-250
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• 2019

Milli-scale crawling robots have been widely studied due to their maneuverability in confined spaces. For successful crawling, the crawling robots basically required to fulfill alternating gait with elliptical foot trajectory. The alternating gait with elliptical foot trajectory normally generates both forward and upward motion. The upward motion makes the aerial phase and during the aerial phase, the forward motion enables the crawling robots to proceed. This simultaneous forward and upward motion finally results in fast crawling speed. In this paper, we propose a novel alternating mechanism to make a crab-inspired eight-legged crawling robot. The key design strategy is an alternating mechanism based on double four-bar linkages. Crab-like robots normally employs gear-chain drive to make the opposite phase between neighboring legs. To use the gear-chain drive to this milli-scale robot system, however, is not easy because of heavy weight and mechanism complexity. To solve the issue, the double-four bar linkages has been invented to generate the oaring motion for transmitting the equal motion in the opposite phase. Thanks to the proposed mechanism, the robot crawls just like the real crab with the crawling speed of 0.57 m/s.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.35-41
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• 2012

To control screen door installed in the subway platform, geared BLDC motors have been being used. However, because of the geared mechanisms, the control profile of the screen door in slow speed is very poor. Moreover, geared mechanism tends to leads system malfunctions and low efficiency. To overcome those problems, in this paper, the techniques of developing hi-efficiency direct drive gearless PMAC motor controller and application example to control the screen door of subway platforms are proposed. The developed system has advantages that; the energy efficiency has been increased by adopting gearless PMAC motor; the system break-down factor has been decreased due to the actuator mechanism has been simplified. In this paper, the screen door control system structure, PMAC motor drive circuit design, implementations of vector control algorithm, and test results are shown.

• Journal of Power Electronics
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• v.16 no.2
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• pp.598-609
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• 2016

The good control performance of permanent magnet linear synchronous motor (LSM) drive systems is difficult to achieve using linear controllers because of uncertainty effects, such as fictitious forces. A backstepping control system using adaptive modified recurrent Laguerre orthogonal polynomial neural network uncertainty observer (OPNNUO) is proposed to increase the robustness of LSM drive systems. First, a field-oriented mechanism is applied to formulate a dynamic equation for an LSM drive system. Second, a backstepping approach is proposed to control the motion of the LSM drive system. With the proposed backstepping control system, the mover position of the LSM drive achieves good transient control performance and robustness. As the LSM drive system is prone to nonlinear and time-varying uncertainties, an adaptive modified recurrent Laguerre OPNNUO is proposed to estimate lumped uncertainties and thereby enhance the robustness of the LSM drive system. The on-line parameter training methodology of the modified recurrent Laguerre OPNN is based on the Lyapunov stability theorem. Furthermore, two optimal learning rates of the modified recurrent Laguerre OPNN are derived to accelerate parameter convergence. Finally, the effectiveness of the proposed control system is verified by experimental results.

• Nuclear Engineering and Technology
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• v.31 no.1
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• pp.1-8
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• 1999

In this paper, we propose a new type of power control system for the rod drive coil of the CEDM of the PWR NPP in order to supply more reliable DC power The electrical modelling of the controlled rod drive coil was done by referring related documentations. The design of the proposed system is based on this electric81 model satisfying the existing specification. A high power DC-DC converter scheme is adopted utilizing the SMPS technique in the design of the proposed system. In order to show the effectiveness of the proposed system, an experimental system with the capability of 3.2 K Watt was set up for a rod with four cores and some computer simulations and experimentations were carried out. The result shows a very similar tracking performance with that of the existing system to the driving command. As a result of this, the proposed method can be applied to the power control system for the rod drive coil of the CEDM of the PWR NPP.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.360-366
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• 2001

This paper show the designing, manufacturing and performance test procedure of a high speed, fixed ratio planetary roller type traction drive as a speed reducer. The arrangement and size design for sun roller, planetary rollers and ring roller are carried out and a proper pre-load mechanism are adopted. To improve transmitting power capacity and endurance limit, nitro-carburized bearing steel and a synthetic traction oil are used. The manufactured and assembled traction drive operated successfully under unloaded conditions. Further tests for various load and speed conditions are executing now to improve the performance of the traction drive.

• Journal of Power Electronics
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• v.15 no.3
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• pp.730-740
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• 2015

This paper presents model reference adaptive system speed estimators based on Type-1 and Type-2 fuzzy logic controllers for the speed sensorless direct torque and flux control of an induction motor drive (IMD) using space vector pulse width modulation. A Type-1 fuzzy logic controller (T1FLC) based adaptation mechanism scheme is initially presented to achieve high performance sensorless drive in both transient as well as in steady-state conditions. However, the Type-1 fuzzy sets are certain and cannot work effectively when a higher degree of uncertainties occurs in the system, which can be caused by sudden changes in speed or different load disturbances and, process noise. Therefore, a new Type-2 FLC (T2FLC) - based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties, improve the performance, and is also robust to different load torque and sudden changes in speed conditions. The detailed performance of different adaptation mechanism schemes are performed in a MATLAB/Simulink environment with a speed sensor and sensorless modes of operation when an IMD is operates under different operating conditions, such as no-load, load, and sudden changes in speed. To validate the different control approaches, the system is also implemented on a real-time system, and adequate results are reported for its validation.