• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1282-1286
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• 1999

This paper presents the DQ transfomation and space vector modulation method to develop a control algorithm of distribution STATCON(STATic CONdenser) for line voltage regulation, dc link voltage regulation and harmonics compensation. The Performance analysis of a PI with ramp comparision and synchronous reference frame current controller is carried out. Based on these analysis, the control performances are desirable to compensate the harmonics and to regulate de link and line voltage of Distribution line.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.489-493
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• 2002

This paper discover another boost vectors in high modulation index In steady states, modulation index of converter operation is normally $0.7\~0.8[p.u]$. Even though zero vectors are not imposed, DC-Link voltage is constant because 3-level boost convert has another boost vectors. and this paper proposes the analysis and the comparison for NPC and H-Bridge converter. It proposed the calculation method for the voltage ripple and charging current of each capacitor and deals with voltage balance problems of each link capacitor they are associated with the switching state, the position of reference voltage vector. Simulation and analysis are used in order to prove validity of the proposed methods.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2359-2361
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• 2000

This paper presents a practical method of realizing Differential GPS(DGPS) using an effective communication link. The DGPS technique is used to correct user's pseudorange measurements with trasmintted correction data from the reference station. An effective communication system is the key element for successful application of the DGPS. In this paper, a practical method for efficient data communication link for DGPS using mobile phone and TCP/IP protocol is presented. Its performance is verified via field test.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.65-70
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• 2017

The structure of MMSE receiver front-ended by CMA(Constant Modulus Array) array working in CDMA forward link which is applicable to LEO spread spectrum satellite communication system is proposed. By using the despreaded pilot signal of forward link as a reference signal, the CMA array can capture multi-path signals securely even in severely faded LEO satellite channel. The remaining MAI (Multiple Access Interference) is cancelled by the cascaded MMSE receiver. Besides theoretical development, through relevant computer simulation, it is proved that the proposed system shows much better BER performance than any other possible candidate systems. As a spatio-temporal receiver mounted on a mobile vehicle, the proposed system also reduces implemental cost and complexity by adopting the simplest algorithm for its spatial and temporal domain processing.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1509-1512
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• 2003

The electric power wheelchair needs to control motor torque and speed for responding to variable actions given by handling a joystick. In this paper a DSP-based BLDC motor controller using a single dc-link current sensor is presented for electric power wheelchair. It is composed by a DSP processor and three-phase inverter module. To control torque, high speed current control is achieved by the PI controller and pulse width modulation (PWM) signals with 25 kHz carrier frequency, which is performed by 200 ${\mu}sec$ cycle. The speed controller computes the new direct current reference from the speed error and the PI control equation. The displacement value by handling the joystick is converted to reference speeds of right and left wheel motors using nonholonomic wheelchair kinematics. Experimental results show that the presented control system is enough to implement a speed servo in wheelchair driving.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1045-1052
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• 2000

In this paper, we propose a method to apply the Input Shaping Technique (IST) to multi-input multi-output (MIMO) systems. In MIMO systems, there is a high possibility of multi-mode residual vibration. The IST filter designed for this multi mode may need a longer time to suppress the residual vibration. Previous works prove that we can shorten the time lag by using negative sequence. This negative sequence, however, causes another problem - it requires excessive control input. In this paper, we provide a remedy to reduce the size of control input by limiting the reference input by limiting the reference input and its derivative. The result of simulations and experiments on a 2 link flexible arm confirmed the effectiveness of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.912-915
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• 1996

The computed-torque method (CTM) shows good trajectory tracking performance in controlling robot manipulator if there is no disturbance or modelling errors. But with the increase of a payload or the disturbance of a manipulator, the tracking errors become large. So there have been many researches to reduce the tracking error. In this paper, we propose a new control algorithm based on the CTM that decreases a tracking error by generating new reference trajectory to the controller. In this algorithm we used the concept of sliding mode theory and fuzzy system to reduce chattering in control input. For the numerical simulation, we used a 2-link robot manipulator. To simulate the disturbance due to a modelling uncertainty, we added errors to each elements of the inertia matrix and the nonlinear terms and assumed a payload to the end-effector. In this simulation, proposed method showed better trajectory tracking performance compared with the CTM.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.448-451
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• 2008

This study is under doing to suggest application manual using assembling reference plane design & standard finish material basis upon material classification code as a tool of a linkage between building design and construction standarization in order to enlarge the applicability of house building material that is produced by the module plant. We can say the goal of building standardization intend not only the improvement of construction productibility but also guarantee of subsequent performance through automatization basis upon informationalization of building design. For a etabilishing of this condition, it is neccessary to link the standardization's result of material--design--construction field. According to this neccessity, we are going to suggest information factor that can make relative business manager easily approach to the standardization practical task.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.130-140
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• 2001

This paper presents the performance of a parallel active power filter(PT) system in unbalanced load condition. The unbalanced load leads to negative sequence of current, and makes 120Hz ripple in the DC-link voltage forcing large capacitance and increases the rating of APF. thus, the separation of negative sequence is performed in synchronous reference frame and controlled to flow into supply network. The validity of the scheme is investigated through simulation and the experimental results for a prototype active power filter system rated at 10kVA.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.1
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• pp.66-73
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• 2016

An Inertial Measurement Unit (IMU)-based Attitude and Heading Reference System (AHRS) can calculate attitude and heading information with long-term accuracy and stability by combining gyro, accelerometer, and magnetic compass signals. Motivated by this characteristic of the AHRS, this paper presents a Motion-Tracking and Localization (MTL) method for a person or walking robot using multi-AHRSs. Five AHRSs are attached to the two calves, two thighs, and waist of a person/walking robot. Joints, links, and coordinate frames are defined on the body. The outputs of the AHRSs are integrated with link data. In addition, a supporting foot is distinguished from a moving foot. With this information, the locations of the joints on the local coordinate frame are calculated. The experimental results show that the presented MTL method can track the motion of and localize a person/walking robot with long-term accuracy in an infra-less environment.