• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.936-941
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• 2011

This paper deals with the issue of motion control of a single rod cylinder-load system using simple adaptive control (SAC) method. Prior to controller design, the experiment of open-loop response has been performed. Based on it, design parameters of transfer function are obtained and used for controller design. The effect of parallel feedforward compensator has been investigated by computer simulation, suppressing the oscillatory motion. Through experiments it is conformed that the SAC method gives good tracking performance compared to the PD control method.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.25-25
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• 2000

This paper presents a design method of sliding mode control (SMC) for single input linear systems with mismatched uncertainties. We define a virtual state based on the controllable canonical form of the nominal system. And we define a sliding surface for the augmented system with a virtual state. This sliding surface makes it possible to use SMC technique with various types of controllers. In this paper, we construct a controller that combines SMC with robust controller. We design a robust controller for the system with only mismatched uncertainties using a form of linear matrix inequality (LMI). We make a virtual state from this robust control input and the states of the nominal system. And we design a sliding mode controller that stabilizes the overall closed-loop system.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.93-98
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• 2022

The purpose of this paper was to propose a method for improving the performance of the open-loop control of single-phase permanent magnet synchronous motor (SP-PMSM), based on a square wave voltage injection. Generally, the SP-PMSM driving systems cmprise a full-bridge inverter and asymmetric air-gap structure of magnetic circuit, because a zero torque occurs on the symmetrical air-gap. As a result, it cannot be started at a specific rotor position. Thus, it is possible to cause the start-up failure at an open-loop control for sensorless operation of SP-PMSM. In this paper, the method with square wave voltage injection considering the nonlinearity of the inverter is presented to resolve the problem. The effectiveness of the proposed algorithm is verified through several experiments.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1971-1973
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• 1997

Space Vector control of linear induction motor without speed sensor is one of the most up-to-date researching subjects to the engineers in the fields of power electronics and control theory. A conveyance SLIM (Single-sided Linear Induction Motor) has required a stable speed and a soft start/stop when the goods convey. So, the close loop control method to use a speed sensor have been adopted and as the speed sensor, a linear encorder has been used. But when the speed sensor used, the application boundary is limited and the confidence of system is diminished because it is sensitive to external environment variations and its cost is very expensive. So, to solve these problems, this paper deals with speed control of the conveyance SLIM using space vector without speed sensorless.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.587-591
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• 2004

This paper proposes a novel current compensation technique that can eliminate the harmonic currents included in line currents without computation of harmonic current components. A current controller with fast dynamics for an active filter is described. Harmonic currents are directly controlled without the need for sensing and computing the harmonic current of the load current, thus simplifying the control system. Current compensation is done in the time domain, allowing a fast time response. The DC voltage control loop keeps the voltage across the DC capacitor constant. High power factor control by an active filter is described. All control functions are implemented in software using a single-chip microcontroller, thus simplifying the control circuit. Any current-controlled synchronous rectifier can be used as a shunt active filter through only the simple modification of the software and the addition of current sensors. It is shown through experimental results that the proposed controller gives good performance for the shunt active filter.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.105-106
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• 2012

A feedback control algorithm for the input voltage control of boost converter is proposed in this paper. The proposed control system is mathematically formulated such that the state feedback gains. The control algorithm does not rely on manual tuning procedures neither use complex adaptive techniques. For the verification of the proposed control algorithm, simulation results of the proposed algorithm using PSIM 9.0 are given.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.456-460
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• 1996

A nonlinear control scheme for preventing limit cycle due to the nonlinearity of themulti-step bang-bang actuator in mechanical position control systems is proposed. A linearized model, SIDF, fora multi-step bang-bang actuator is introduced to compensate the nonlinearity of the multi-step bang-bang actuator. Using that model, a $H_{\infty}$robust controller for position control systms with a bang-bang actuator is proposed by loop shaping tecniques with normalized coprime factorization stabilization to address the robustness. The proposed scheme needs a smaller deadband as a result of compensating the nonlinearity of the bang-bang actuator. A single-axis servo system is served in order to verify the proposed control scheme experimentally. Experimental results show that the controller can satisfy the special intersts, silent contact switching of the actuator.r.

• Smart Structures and Systems
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• v.5 no.3
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• pp.279-290
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• 2009

Two degrees of freedom resonant systems are employed to improve the resonant property of resonant sensor, as compared to a single degree of freedom resonant system. This paper presents design, development and testing of two degrees of freedom resonant sensor. To measure absolute mass, cantilever shaped two different masses (smaller/absorber mass and bigger/drive mass) with identical resonant frequency are mechanically linked to form 2 - Degree-of-Freedom (DOF) resonator which exhibits higher amplitude of displacement at the smaller mass. The same concept is extended for measuring differential quantity, by having two bigger mass and one smaller mass. The main features of this work are the 3 - DOF resonator for differential detection and the microcontroller based closed loop electronics for resonant sensor with piezoelectric sensing and excitation. The advantage of using microcontroller is that the method can be easily extended for any range of measurand.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.126-128
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• 2018

Solar array simulator (SAS) is a special DC power supply that regulates the output voltage or current to emulate characteristics of photovoltaic (PV) panels. Especially, the control of SAS is a challenging task due to the nonlinearity in the output curve, which is dependent on irradiance as well as temperature and is determined by panel materials. Conventionally, both current-mode control and voltage-mode control should be alternated by partitioning the operating curve into multiple sections, which is not only for the measurement noise problem with the feedback sensing but also for the control stability issue near the maximum power point. However, the occurrence of transition among different controllers may deteriorate the overall performance. To eliminate the mode transitions, a novel single controller scheme has been introduced in this paper, where the reference operating projection technique enables simple, smooth and numerically stable control. Theoretical consideration on the loop stability issue is discussed and the performance is verified experimentally for the emulation of a PV panel data in view of stability and response speed.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.99-103
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• 2012

This paper presents a new switch-control approach for multiphase interleaved converters. Development of the proposed technique is based on control-signal generation for multi-unit synchronization. Current sharing among the switching cells and voltage regulation are achieved by means of a multi-loop control scheme regardless of changes in input voltage and load. System stability is ensured by single-pole compensation. This proposed technique is straightforward, reliable and inexpensive, and can be applied to any higher number of cells without difficulty.