• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.199-207
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• 1998

This paper presents the design and the control of three degree-of-freedom(DOF) fine positioning device based on an electro-magnetic force. The device is designed by use of a magnetic circuit theory and it is capable of fine motion due to the electro-magnetic force. The device consists of permanent magnets, yokes and coils. The magnetic fluxes generated from the permanent magnets constitute magnetic paths through steel, whereas the coils are arranged into the gap between two surfaces of the yokes. Therefore, by supplying current to the coils, the coils are capable of some motions due to Lorentz forces. For the optimal design of the actuating system, the system parameters are defined and investigated under the given constraints. From the system modeling in small displacement, three decoupled equations of motion are obtained. To get better performance of the system, a PID controller is implemented. Experimental results are presented in terms of time response and accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.260-260
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• 2000

In this work, we have developed a 2 degree of freedom(DOF) motion simulator that can generate the sensation of motion in a 6 DOF space. The motion base has the DOF of roll and pitch, and the purpose of the motion base is to create the sensation of riding a vehicle in a 3D space by controlling the motion base. The dynamics of the mechanism was analysed and the optimal design of the motion base mechanism has been reached. The prototype motion base mechanism was developed and tested. The multi-axis motion controller(MMC) was used to control the two ac servo motors that drive the roll and pitch motion.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.496-499
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• 2002

The LQG/LTR controller is a robust and stable control which is systematic method with a view of engineering. And the H$^{\infty}$ scheme is adopted for the design of the controller to reduce the effects of the disturbances. In this paper, LQG/LTR and H$^{\infty}$ Controller Design of Lateral Control System for an Automobile is developed with 3 DOF (degree-of-freedom) model. The performance has been compared for the employed two types of controllers via computed simulations. The results show that the H$^{\infty}$ controller provides more robustness property for the disturbances and lower control input.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.318-321
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• 2002

The LQG/LTR controller is a robust and stable control which is systematic method with a view of engineering. And the H$^{\infty}$ scheme is adopted for the design of the controller to reduce the effects of the disturbances. In this paper, LQG/LTR and H$^{\infty}$ Controller Design of Lateral Control System for an Automobile is developed with 3 DOF (degree-of-freedom) model. The performance has been compared for the employed two types of controllers via computed simulations. The results show that the H$^{\infty}$ controller provides more robustness property for the disturbances and lower control input.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1070-1078
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• 2000

A nonlinear adaptive flight control system is proposed using a backstepping controller with neural network controller. The backstepping controller is used to stabilize all state variables simultaneously without the two-timescale assumption that separates the fast dynamics, involving the angular rates of the aircraft, from the slow dynamics which includes angle of attack, sideslip angle, and bank angle. It is assumed that the aerodynamic coefficients include uncertainty, and an adaptive controller based on neural networks is used to compensate for the effect of the aerodynamic modeling error. It is shown by the Lyapunov stability theorem that the tracking errors and the weights of neural networks exponentially converge to a compact set. Finally, nonlinear six-degree-of-freedom simulation results for an F-16 aircraft model are presented to demonstrate the effectiveness of the proposed control law.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.101.6-101
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• 2002

The LQG/LTR controller is a robust and stable control which is systematic method with a view of engineering. And the scheme is adopted for the design of the controller to reduce the effects of the disturbances. In this paper, We develop an algorithm that decides the distance and directions between the guide line that is made by a series of magnets and MR sensors of vehicle. LQG/LTR and Controller Design of Lateral Control System for a vehicle is developed with 3 DOF (degree-of-freedom) model. The performance has been compared for the employed two types of controllers via computed simulations. The results show that the controller provides more robustness property for t...

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.206-213
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• 2001

An overlapping decentralized robust EA(eigenstructure assignment) controller is designed for an active suspension system of a vehicle based on a full car model with 7-degree of freedom. Using overlapping decomposition, the full car model is decentralized by two half car models. For each half car model, an effective and disturbance suppressible controller can be obtained by assigning appropriately a left eigenstructure of the system. The performance of the proposed overlapping decentralized robust EA controller is compared with that of a conventional centralized EA controller through computer simulations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.229-234
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• 2002

Immune system is an evolutionary biological system to protect Innumerable foreign materials such as virus, germ cell, and et cetera. Immune algorithm is the modeling of this system'response that has adaptation and reliableness when disturbance occur. In this paper, immune algorithm controller was proposed to control four wheels steering(4ws) Automated Guided vehicle(AGV) in container yard. And then the simulation result was analysed and compared with the results of NN-PID controller.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.138-144
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• 2000

Robot manipulators, which are nonlinear structures and have uncertain system parameters, have complex in dynamics when are operated in unknown environment. To compensate for estimate errors of the uncertain system parameters and to accomplish the desired trajectory tracking, nonlinear robust controllers are appropriate. However, when estimation errors or tracking errors are large, they require large input torques, which may not be satisfied due to torque limits of actuators. As a result, their stability can not be guaranteed. In this paper, a new robust control scheme is presented to solve stability problem and to achieve fast trajectory tracking in the presence of torque limits. By using fuzzy logic, new desired trajectories which can be reduced are generated based on the initial desired trajectory, and torques of the robust controller are regulated to not exceed torque limits. Numerical examples are shown to validate the proposed controller using an uncertain two degree-of-freedom underwater robot manipulator.

• Journal of KSNVE
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• v.7 no.5
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• pp.803-810
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• 1997

This paper is concerned with the vibration control of multi-layer structure for ultra-tall buildings and main tower of large bridge etc. We have modeled the multi-layer structure with the distributed mass system as the lumped mass system of two-degree-of-freedom structure and made experimental equipment. The $H_\infty$control theory was applied to the design of the control system. The designed control system was simulated by computer. As a result, the designed $H_\infty$controller showed the good vibration control performance to impulse response and frequency response.