• Journal of Multimedia Information System
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• v.8 no.1
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• pp.69-74
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• 2021

This paper accumulates the product structure data such as bond obligation ratio and investment ratio for variable insurance using crawling from the insurance company's API, also accumulates variable insurance income and project expenses for variable insurance using crawling from the API of life insurance association. From these accumulated data, the correlation coefficient between fund product and customer preference is calculated with an investment algorithm, and variable insurance funds by customer investment preference and product structure are recommended according to market conditions. From the simulation results, it is shown that the proposed variable insurance management system properly recommends and manages variable insurance according to customer preferences.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.9
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• pp.671-683
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• 1989

A controller of interconnected power systems is investigated using an optimal multidimensional variable structure control. The switching hyperplane of the variable structure stabilizer is obtained by minimizing a quadratic performance index in continuous-time. A special feature of the optimal multidimensional variable structure stabilizer is that, when it is operated in the so-called sliding mode, the system response becomes insensitive to changes in the plant parameters. A digital simulation is performed by a digital computer using the Advanced Continuous Simulation Language (ACSL) package, which shows that the dynamic performance of the power system in response to mechanical torque changes is improved when optimal multidimensional variable sturcture stabilizers are employed.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.458-463
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• 1997

In this paper, we propose a variable structure control approach for the system with matched and unmatched uncertainty. By using time-varying sliding mode, the reaching mode is removed, and the design methodology represents a realistic design approach with quadratic criterion for systems incorporating both matched and unmatched uncertainties. The criterion contains states and linear part of input for all time. The practical application of the control strategy is presented in the design of a stability augmentation system for an aircraft is presented.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.6
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• pp.492-495
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• 2005

This paper deals with the problem of estimating the asymptotic stability region(ASR) of uncertain variable structure systems with bounded control. Using linear matrix inequalities(LMIs) we estimate the ASR and we show the exponential stability of the closed-loop control system in the estimated ASR. We show that our estimate is always better than the estimate of [3].

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.12
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• pp.556-561
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• 2002

In this paper, a discrete-time variable structure controller for linear time-varying sampled-data systems with disturbances is proposed. The proposed method guarantees that the system state if globally uniformly ultimately bounded (G.U.U.B), and the ultimate bound is shown to be the order of T, O(T), where T is a sampling period.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1474-1482
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• 2018

As an essential means of generator voltage regulation, excitation control plays an important role in controlling the stability of the power system. Therefore, the reasonable design of an excitation controller can help improve the system stability. In order to raise the robustness of the generator exciting system under outside interference and parametric perturbation and eliminate chattering in the sliding mode control, this paper presents a generator excitation control based on the quasi-sliding mode pseudo-variable structure control. A mathematical model of the synchronous generator is established by selecting its power, speed and voltage deviation as state variables. Then, according to the existing conditions of the quasi-sliding mode, a quasi-sliding mode pseudo-variable structure controller is designed, and the parameters of the controller are obtained with the method of pole configuration. Simulations show that compared with the existing methods, the proposed method is not only useful for accurate voltage regulation, but also beneficial to improving the robustness of the system at a time when perturbance happens in the system.

• Journal of Drive and Control
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• v.18 no.4
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• pp.52-58
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• 2021

The variable structure controller is designed such that in sliding mode, the system moves along the switching plane in the vicinity of the switching plane, thus it is robust because it is not affected by the parameter fluctuations of the plant. However, a controller based on a variable structure may not meet the desired performance when it is commanded to track any input or is exposed to disturbances. This study proposes a sliding mode controller that follows the IVSC (Integral Variable Structure Control) approach with ELO (Extended Luenberger observer) to solve this problem. The proposed sliding mode control is applied to the velocity control of the hydraulic motor. The sliding plane was determined by the pole placement, and the control input was designed to ensure the existence of the sliding mode. The feasibility of modeling and controller are reviewed by comparing with conventional proportional-integral control through computer simulation using MATLAB software and experimenting on the cases of significant plant parameter fluctuations and disturbances.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.232-237
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• 1991

Digital Variable Structure Controller(DVSC) is proposed to control variable speed recirculating pump for hot-water heating control system. In this study, nonlinear sliding line is used beyond output error boundary layer and PID sliding line is used within the layer. For long dead time compensation, constraint is added to Smith predictor algorithm. Steady state error is eliminated by using the proposed sliding line in spite of heating load change. By decreasing sampling time, good sliding motion is yielded but system output noise bv flow dynamics is amplified.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.9
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• pp.60-66
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• 1997

WE consider the stabilization of a class of multivariable nonlinear system using variable structure output feedback control. A high-gain observer is used to estimate state variable while rejecting the effect of the disturbances. We design a globally bounded output feedback variable structure controller that semi-globally stabilize the closed-loop system, while state variables do not exhibit a peaking.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.8
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• pp.124-133
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• 1996

This paper presents the implementation of variable structure control system for a linear or nonlinear system using neural networks. The overall control system consists of neural network controller and a reaching mode controller. While the former approximates the equivalent control input on the sliding surface, the latter is used to bring the entire system trajectories toward the sliding surface. No supervised learning procedures are needed and the weights of the neural network are tuned on-line automatically. The neural netowrk-based variable structure control system is applied to a nonlinare unstable inverted pendulum system through computer simulations, and implemented using a microcomputer (80486-50MHz) and applied to the DC servomotor position control system. Simulation and experimental results show the expected approximation sliding property is occurred. The proposed controller is compared with a PID controller and shows better performance than the PID controller in abrupt plant parameter change.