• Korean Journal of Remote Sensing
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• v.1 no.1
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• pp.89-97
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• 1985

An algorithm for the Hill-Sliding Clustering (HSC) method was developed using the BASIC language for Apple II personal computer. It was designed for initialization of clusters from multivariate multimodal Gaussian data. Landsat multispectral imagery data of a Korean coastal area were used for its performance test. The test showed encouraging results.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.8
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• pp.735-743
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• 2010

A new Fuzzy sliding mode controller is proposed to improve the cornering performance of the four wheel hybrid vehicles. The Fuzzy sliding mode control is applied for the control of rear motor and EHB (Electro-Hydraulic Brake) to improve the cornering performance. The modeling of the automobile is simplified that each of the two wheels is modeled as two degrees of freedom object and the friction coefficient between the wheel and the ground is assumed to be constant. The output of the Fuzzy sliding mode algorithm is the direct yaw moment for the rear wheels, which compensates for the slip angle. Through the simulations using ADAMS and MATLAB Simulink, the cornering performance of the proposed algorithm is compared to the conventional PID to show the superiority of the proposed algorithm. In the simulation experiments, the J-Turn and single lane change are used for each of the Fuzzy sliding mode algorithm and PID controller with the optimal gains which are tuned empirically.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.684-688
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• 1996

In this paper, to overcome drawbacks of variable structure control system a self-tuning fuzzy sliding mode control algorithm using gradient descent method is proposed. The proposed method has the characteristics which are viewed in conventional VSC, e.g. insensitivity to a class of disturbance, parameter variations and uncertainties in the sliding mode. To demonstrate its performance, the proposed control algorithm is applied to a one-degree of freedom robot arm. The results show that both alleviation of chattering and performance are achieved.

• Proceedings of the KIEE Conference
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• 2004.07e
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• pp.33-36
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• 2004

In this paper, a new estimation algorithm for the rotor speed for SRM drives is described. The algorithm is implemented by the sliding mode observer. The stability and robustness of the sliding observer for the parameter variations of the SRM are proved by variable structure control theory. Variable speed control of the SRM is accomplished by the estimated speed. Experiment results verify that the sliding mode observer is able to estimate the speed.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.253-256
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• 1996

In this paper, A new time-varying sliding surface design using eigenvalue locus is proposed to achieve fast and robust in a class of high-order uncertain dynamic system. A moving sliding surface(MSS) was proposed earlier for the second-order variable structure control systems(VSCS). This methodology led to fast and robust control responses of the second-order VSCS. However, the moving algorithm of the MSS was too complicated to be employed the high-order VSCS. To resolve this problem, we propose a new moving algorithm that switching surface moves such that the eigenvalues of equivalent system in the sliding mode have a predetermined locus. Using the proposed surface fast and robust behaviors are accomplished. The problem of chattering can be eliminated by using a boundary layer of switching surface. The efficiency of proposed algorithm is illustrated by an application to four-order workbench.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.449-452
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• 1997

In this paper, we suggest a variable structure controller using the time-varying nonlinear sliding surface instead of the fixed sliding surface, which has been the robustness against parameter variations and extraneous disturbance during the reaching phase. As appling TS fuzzy algorithm to the regulation of the nonlinear sliding surface, the reaching time of the system trajectory is faster than the fixed method . This proposed scheme has better performance than the conventional method in reaching time parameter variation and extraneous disturbance. To demonstrate its performance, the proposed control algorithm is applied to a rotational inverted pendulum.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.119-121
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• 2005

The sliding-mode control technique could make a system unstable which external disturbance and uncertainty exists in. This paper suggests a robust sliding-mode control algorithm which can be applied to a linear system with parameter uncertainties. To reduce the chattering effect, the whole system is comprised of using a state variable in which the state's estimated value is added. The condition of estimated state results from state observer. The proposed control algorithm uses the optimal feedback controller following the dynamic system equation which consists of a state variable resulting from its own state variable, controller input, estimated state variable. Through comparison with the time optimal control algorithm using simulation, the suggested algorithm shows the improved stability and robustness while it manifests the fast tracking characteristics.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.2
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• pp.851-857
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• 2019

A new robust sliding mode control with disturbance and state observers has been proposed to control the nozzle angle of a water-jet system for a Unmanned Surface Vehicle (USV). As the water-jet system of a ship is subjected to direct disturbances owing to the exposure to the marine environment in water, it requires a robust control. A state observer and a disturbance observer are added to the water jet nozzle control system to achieve a robust control against disturbances. To verify the performance of the proposed algorithm, a test bed is constructed by a propulsion system used in the popular USV. This proposed algorithm has been evaluated by comparing to the existing algorithm through experiments. The results show that the performance of the proposed algorithm is better than that of the conventional PID or sliding mode controller when controlling the steering of the USV with disturbances.

• Transactions on Control, Automation and Systems Engineering
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• v.3 no.1
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• pp.58-65
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• 2001

This paper proposes a self tuning fuzzy inference method by the genetic algorithm in the fuzzy-sliding mode control for a robot. Using this method, the number of inference rules and the shape of membership functions are optimized without an expert in robotics. The fuzzy outputs of the consequent part are updated by the gradient descent method. And, it is guaranteed that he selected solution become the global optimal solution by optimizing the Akaikes information criterion expressing the quality of the inference rules. The trajectory tracking simulation and experiment of the polishing robot show that the optimal fuzzy inference rules are automatically selected by the genetic algorithm and the proposed fuzzy-sliding mode controller provides reliable tracking performance during the polishing process.

• Journal of IKEEE
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• v.11 no.1 s.20
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• pp.1-14
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• 2007

In this paper, a design of an integral augmented nonlinear optimal variable structure system(INOVSS) is presented for the prescribed output control of uncertain MIMO systems under persistent disturbances. This algorithm basically concerns removing the problems of the reaching phase and combining with the nonlinear optimal control theory. By means of an integral nonlinear sliding surface, the reaching phase is completely removed. The ideal sliding dynamics of the integral nonlinear sliding surface is obtained in the form of the nonlinear state equation and is designed by using the nonlinear optimal control theory, which means the design of the integral nonlinear sliding surface and equivalent control input. The homogeneous $2{\upsilon}(\kappa)$ form is defined in order to easily select the $2{\upsilon}$ or even $(\kappa)-form$ higher order nonlinear terms in the suggested sliding surface. The corresponding nonlinear control input is designed in order to generate the sliding mode on the predetermined transformed new surface by means of diagonalization method. As a result, the whole sliding output from a given initial state to origin is completely guaranteed against persistent disturbances. The prediction/predetermination of output is enable. Moreover, the better performance by the nonlinear sliding surface than that of the linear sliding surface can be obtained. Through an illustrative example, the usefulness of the algorithm is shown.