• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.652-655
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• 1996

This paper develops an AC motor controller for applications. The AC motor controller is designed based on the variable structure control method and a variable structure disturbance observer is added to reduce the effects of exogenous disturbances. The designed controller is installed on the z-axis of a CNC machining center and milling experiments were performed. The results show improved performance on both position and speed tracking, when compared to the factory-designed servo controller.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.37.5-37
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• 2001

A robust control for robot manipulators actuated by induction motors using neural networks(NNs) is considered. The control is designed to compensate for nonlinear dynamics associated with the mechanical subsystem and the electrical subsystems only with the measurements of link position, link velocity and stator winding currents. Two-layer NNs are used to approximate unknown functions occurring from parameter variation during backstepping design process. Specially, through the use of nonlinear observers for rotor flux, observed backstepping controller is designed to achieve uniform ultimately bounded link position tracking of the given reference signal ...

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.500-502
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• 1998

This paper proposes position controller of linear motor using adaptive control algorithm. Some simulation results show the feasibility of the proposed controller for tracking control of linear motor.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.147-155
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• 2001

A new displacement type web position control system for cold mills using QFT is presented. The control system features an inner-outer cascaded system in which the inner loop provides the position tracking control of the hydraulic system and the outer loop provides the position regulation control of the web. By the sensitivity analysis and computer simulation, it is verified that the proposed control system has better robust stability and performance than the conventional control system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.31-38
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• 2002

A new steering-type web position control system for cold mills using QFT is presented. The control system features an inner-outer cascaded system in which the inner loop provides the position tracking control of hydraulic system and the outer loop provides the position regulation control of the web. By the sensitivity analysis and computer simulation, it is verified that the proposed control system has better robust stability and performance than the conventional PH) control system.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1213-1221
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• 2007

In most case of previous research about vehicle control system, external error occurred by unexpected environmental situation was hardly considered. However, in this paper, to have more accurate position control of differential derive vehicle, we separate the error as an internal error and external error. To calculate the vehicle position in real time, we introduced the Dead-Reckoning algorithms and the simulation result show that the proposed internal and external error control system has fast and accurate position tracking with remarkable diminishment of orientation error. The results reported here can easily be extended to the control of similar type vehicle.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.842-847
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• 2008

This paper proposes a new sliding-surface-based tracking control system for nonholonomic mobile robots with disturbance. To design a robust controller, we consider the kinematic model and the dynamic model of mobile robots with disturbance. We also propose a new sliding surface to solve the problem of previous study. That is, since the new sliding surface is composed of differentiable functions unlike the previous study, we can obtain the control law for arbitrary trajectories without any constraints. From the Lyapunov stability theory, we prove that the position tracking errors and the heading direction error converge to zero. Finally, we perform the computer simulations to demonstrate the performance of the proposed control system.

• Transactions of The Korea Fluid Power Systems Society
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• v.1 no.1
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• pp.1-9
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• 2004

This paper addresses an approximation and tracking control of recurrent neural networks(RNN) using two-dimensional iterative learning algorithm for an electro-hydraulic servo system. And two dimensional learning rule is driven in the discrete system which consists of nonlinear output function and linear input. In order to control the trajectory of position, two RNN's with the same network architecture were used. Simulation results show that two RNN's using 2-D learning algorithm are able to approximate the plant output and desired trajectory to a very high degree of a accuracy respectively and the control algorithm using two same RNN was very effective to control trajectory tracking of electro-hydraulic servo system.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.10
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• pp.1029-1034
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• 2006

In this paper, the tracking control of an automatic pipe cutting robot, called APCROM, with a magnetic binder is studied. Using magnetic force APCROM, a wheeled robot, binds itself to the pipe and executes unmanned cutting process. The gravity effect on the movement of APCROM varies as it rotates around the pipe laid in the gravitational field. In addition to the varying gravity effect other types of nonlinear disturbances including backlash in the driving system and the slip between the wheels of APCROM and the pipe also cause degradation in the cutting process. To maintain a constant velocity and consistent cutting performance, the authors adopt a repetitive learning controller (MRLC), which learns the required effort to cancel the tracking errors. An angular-position estimation method based on the MEMS-type accelerometer is also used in conjunction with MRLC to compensate the tracking error caused by slip at the wheels. Experimental results verify the effectiveness of the proposed control scheme.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.175-180
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• 2005

Incorrections between model and plant are parameter, system order uncertainties and modeling error due to disturbance like friction. Therefore to achieve a good tracking performance, adaptive discrete time sliding mode tracking controller is used under time-varying desired position. Based on the diophantine equation, a new discrete time sliding function is defined and utilized for the control law. Robustness is increased by using both a recursive least-square method and a sliding function-based nonlinear feedback. The effectiveness of the proposed control algorithm is proved by the results of simulation and experiment.