• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.246-250
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• 1995

This paper presents a method in analyzing the output force/moments transmission form the applied input forces of the paralled manipulator. Like a serial manipulator the Jacobian matrix introduced in the paper plays role in relating the output forces/monents with the input forces. The force/moment manipulability have been investigated by considering the force transmission and momen transmission independently. Sensitivity analysis has been done and an illuatrating example is given.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1076-1078
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• 1996

In this paper, we design the robust controller for MIMO system using multiple fuzzy logic controller. Based on the knowledge of system input/output data, we introduce the simple adaptation laws to approximate the decoupling matrix from input channel to output channel. The proposed control algorithm is applied numerical example.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.6
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• pp.550-559
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• 2005

The matrix converter provides sinusoidal input and output wave forms, bidirectional power flow, controllable input power factor and a long life, compared to the VSI(Voltage Source Inverter) with diode rectification stage at the input. However it has tasks, such as complexity of the control method, ride-through problem and low voltage-ratio limitation, to overcome for commercializing, This paper describes the design, construction and implementation of matrix converter based on space vector modulation technique. The implemented prototype of matrix converter is built using the exclusive IGBT module and control circuit constituted with DSP and CPLD and it has an input filter, overvoltage protection circuit and commutation means for overcoming practical issues. The good results tested using an induction motor are also presented.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.4
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• pp.337-344
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• 2012

A matrix converter is used for converting AC/AC power directly. In order to generate sinusoidal input/output waveform in matrix converter, it uses nine bidirectional switches and PWM modulation. This paper presents an analytical averaged loss model of matrix converter with DDPWM(direct duty ratio PWM) and proposes a new switching method for reducing switching losses. A Mathematical loss models with average magnitude of voltage/current are classed as conduction and switching loss. The proposed switching pattern is improved with existing DDPWM. To prove improved efficiency with proposed DDPWM, this paper compares losses between suggested switching pattern and conventional switching pattern using mathematical and simulation method. Each loss types are influenced by environmental factors such as temperature, switching frequency, output current and modulation method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.9 no.3
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• pp.127-131
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• 1984

The IOVMM(Incoherent Optical Vector Matrix Multiplier) is constructed, which can process much information very fast by incogerent light source, and its experimental results are compared with the theoretical values. The input vector and matirx elements are limited to the positive number in this paper. The input vector is made by the LED array and the matrix is encoded on the film by the area modulation method. The result of the vector-matrix multiplication is detected by the photodiode array through the lens system. The analog multiplexer is used for looking at output signal on one channel.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.21-22
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• 2010

Matrix converter is direct power conversion system. Matrix converter has many merits that possible bidirectional power flow, input power factor own control and system without DC-link. But matrix converter has some demerits that need many switching devices and switching loss. This paper suggest optimal matrix converter control scheme for improvement for switching loss part. Proposed control scheme verified that 10% improvement in efficiency, input current's harmonic loss and output voltage's EMI improvement.

• Journal of Power Electronics
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• v.17 no.4
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• pp.1048-1057
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• 2017

An indirect matrix converter (IMC) is a modern power generation system that enables a direct ac/ac conversion without the need for any bulky and limited lifetime electrolytic capacitor. This system also allows four-quadrant operation, generation of sinusoidal output voltage waveforms with variable frequency and amplitude, and control of input power factor. This study proposes a pulse-width modulation-based sliding-mode controller to achieve unity input-power factor operation of the IMC independently of the active power exchanged with the grid, as well as a fast dynamic response. The designed equivalent control law determines, at each sampling period, the appropriate q-axis component of the modulated input current to be injected into the grid through the LC input filter. An integral term of the error is included in the expression of the sliding surface to increase the accuracy of the control method. A double space vector modulation method is used to synthesize the direction of the space vector of the input currents as required by the sliding-mode controller and the space vectors of the target output voltages. Simulation and experimental results are provided to show the effectiveness and evaluate the performance of the proposed control method.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.2
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• pp.112-119
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• 2003

Generally, PID controller is not suitable to control multi variable system because it is very difficult to tune the PID gains. However, this paper shows that it is not hard to tune the PID gains if we can find a Jacobian matrix of the system. The Jacobian matrix expresses the ratio of output variations according to input variations. It is possible to adjust the input values in order to reduce the output error using the Jacobian. When the colt function is composed of error related terms, the gradient approach can tune the PID gains to minimize the function. In simulation, a hydrofoil catamaran with two inputs and two outputs is applied as a multi variable system. We can easily get the multi variable PID controller by the proposed teaming method. When the controller is compared with LQR controller, the performance is as good as that of LQR controller with a modeling equation.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.6
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• pp.821-827
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• 1995

This paper presents a process control language for constructing multiloop control system. which include advanced control algorithms. In order to make controller, this language uses function blocks that do specific operations. Then, the total control algorithm is a set of function blocks, of which each block is represented as a function code. The function code is a line of simple ASCII codes denoting function, input, output, parameters. It is possible to use variables as input/output port of any block. Compared with other language using function block concept, the proposed one enables to use advanced control algorithms undefinitely, such as fuzzy, neural network, predictive controller, etc., because vector and matrix variables as input/output can be used freely in this language. To raise flexibility, we put an intermediate level, which is C-language code, between function code and target-dependent operation code.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.6
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• pp.489-494
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• 2013

This paper tackles the problem of designing a dynamic output-feedback control for linear discrete-time norm-bounded uncertain systems with input saturation. By employing a LPV (Linear Parameter Varying) instead of LTI (Linear Time-Invariant) control, the useful information on interpolation parameters appearing in the procedure of representing saturation nonlinearity as a convex polytope is additionally applied in the control design procedure. By solving the addressed problem that can be recast into a convex optimization problem characterized by LMIs (Linear Matrix Inequalities) with one prescribed scalar, the vertices of convex set containing an LPV output-feedback control gain and the associated maximal invariant set of initial states are simultaneously obtained.