• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.9-18
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• 2007

This paper proposes the modeling of sensorless drive system using 120 degree conduction method for IPM (Interior Permanent Magnet) BLDC motors and analyzes characteristics of the terminal voltage that is used to detect the rotor position. This paper shows that the ZCP (Zero-Crossing Point) of the measured terminal voltage used In sensorless control is ahead of that of the back EMF of IPM motors because they have a saliency. This research also analyzes that the amount of position detection error is related to saliency, rotor speed, and load condition. In addition, this paper shows that motors have bigger advance angles than we have expected because the ZCP of terminal voltage precedes the actual ZCP, and under operation conditions such as heavy load and high speed it may generate abnormal currents that flow toward opposite direction after phase current becomes zero.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.740-743
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• 1997

Reference models are used in many control algorithms for improvement of transient response characteristics. They provide desired trajectories that the plant should follow. Most control systems have bounded control inputs to avoid saturation of the plant. If we design reference models that do not account for limits of control inputs, control performance of the system may be deteriorated. In this paper, therefore, the way of determining variable reference models for TDC(time delay control) technique is proposed. The variable reference model is determined based on the information of bounded control inputs and reference inputs. This proposed method is also verified by application to the position control experiment using the BLDC motor.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.489-492
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• 2000

브러쉬없는 직류전동기의 위치제어를 위한 퍼지가변구조제어기를 설계한다. 특히 본 논문에서는 기존의 퍼지제어 기법에서 얻을수 있는 특징으로부터 하나의 전건부 변수만을 가지는 간단한 퍼지논리제어기의 설계를 기술한다. 가변구조제어는 시스템의 파라메터 변화나 외란에 둔감한 특성을 갖는다. 하지만 리칭페이스에서는 문제가 된다. 이를 개선하기 위하여 본 논문에서는 지수항을 추가한 비선형 슬아이딩면을 구성한다. 그리고 나서 비선형적 슬라이딩면과 슬라이딩면의 변화율을 입력으로하는 퍼지 제어기를 설계한다. 이러한 2-입력 퍼지가변구조제어기의 제어 규칙표로부터 슬라이딩면 하나만을 입력으로 가지는 단일입력 퍼지 가변구조 제어기를 설계한다. 이들 제어기의 성능을 입증하기 위하여 시뮬레이션과 실험을 수행한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.70-75
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• 2010

The objective of this paper is to propose a new velocity measurement method for an electro-mechanical fin actuator. The model of the electro-mechanical fin actuator includes uncertainties such as unknown disturbances and parameter variations in flight condition. So, an electro-mechanical fin actuator system needs robust control algorithm which requires not only position information but also velocity information. Usually, analog tachometers have been used for velocity feedback in an electro-mechanical fin actuator. However, using these types of sensors have problems such as the cost, space, and malfunction. These problems lead to propose a new velocity measurement method using linear type Hall-effect sensor. In order to verify the proposed method, several experiments are performed using Model Following Sliding Mode Controller(MFSMC). It is shown that the MFSMC with a new velocity measurement method using linear type Hall-effect sensor can satisfy the requirements without using of velocity sensor.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.2
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• pp.166-173
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• 1999

Reference models are used in many control algorithms for improvement of transient response characteristics. They provide desired trajectories that the plant should follow Most control systems have bounded control inputs to avoid saturation of the plant. If we design the reference models that do not account for limits of the control inputs, control performance of the system may be deteriorated. In this paper a new approach of avoiding saturation by varying the reference model for TDC(time delay control) based systems subject to step changes in the reference input. In this scheme, the variable reference model is determined based on the information on control inputs and the size of the step changes in the reference inputs. This scheme was verified by application to the BLDC motor position control system in simulations and experiments. The responses of the TDC with the variable reference model showed better tracking performance than that with the fixed reference model.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.92-94
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• 1997

A stabilizing system of EOTS is constructed. This system has two major parts. One of them is for detecting the moving motion of a vehicle with electronic gyroscope. The other is for driving of two axes of the platform where the sensor is attached. The controller used in this paper is DSP(TMS320c31) and two BLDC DD motor are used.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.353-356
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• 2008

This paper is proposed that the photovoltaic/fuel cell hybrid generation system for the stand-alone system. In case of the photovoltaic generation system, it depends on the weather condition, irradiation and so on... On the contrary, fuel cell has not this limitation. It can be interactive generation system between photovoltaic and fuel cell. This paper simulated stand-alone co-generation system based on the control of DC link. Moreover, 1[kw] BLDC motor system with speed and hysteresis current controller is used for the proposed system.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.9
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• pp.951-959
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• 2013

In order to improve the speed performance of the direct drive mechanical systems, a comprehensive analysis of the velocity ripples of blushless DC motors should be required. Every motor has a certain level of torque ripples when it generates power, and the generated torque ripple also makes the velocity ripples in the final output stage in speed control system. In this paper, a novel algorithm for reducing velocity ripples is proposed based on the modeling of torque ripples for BLDC motors. Various algorithms have been made for torque ripples, but usually they should be installed inside the amplifier logic, result in the difficulties of flexibility for various kinds of torque ripples. The proposed algorithm was developed for being ported in the controller not the amplifier, and it has the capability of the automatic compensation adjustment. The performance of the proposed algorithm was verified by effective simulations and experiments.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.353-359
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• 2020

In this study, the controller structure and control algorithm of medical robot bed developed for pressure ulcer prevention and healing are described. The existing pressure ulcer prevention mattress is operated manually and the remaining maximum body pressure exceeds the pressure of ulcer generation, so there is always room for pressure ulcers. However, the system developed in this study does not generate the pressure ulcers because the body pressure drops to zero when the keyboard of the bed descends using the active electric driving keyboard. In addition, even if the bed is raised and the pressure above the critical body ulcer pressure is abnormal, the device and the control algorithm are designed so that the lasting time is within the pressure ulcer generation critical time and the pressure ulcer itself is not generated. The bed key board motor is a motor designed with the BLDC servos suitable for medical use and these can communicate each other easily through CAN(Car Area Network). The system is new medical robot bed that is effective in preventing pressure ulcers and will be distributed to many patients suffering from pressure ulcers.