• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.68.6-68
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• 2001

There is a looper for the safety threading between stands in finishing mill. In this looper system, it is 2 inputs 2 outputs MIMO )Multi Input Multi Output) system, which has two inputs that are the angle of looper and the tension of Strip and has two outputs that are the torque of looper motor and the speed of Mill Motor. In tension controller of looper, it calculates the range of tension variation into the compensation value of speed and outputs to the speed controller of Mill Motor, so that it controls the tension of strip between stands. In this study, using this tension controller of looper, we adjust the establishment value of ...

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.263-266
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• 2003

In this paper, we have proposed a realization method of tactile sense of virtual objects using multi-layer Neural Networks(NN). Inputs of the NN are position data of non-rigid objects and outputs of the NN are forces at that time and point. First, the position and forte data are measured from non-rigid objects (a sponge and a balloon) using two PHANToMS, one as a master and the other as a slave manipulator, then the data are used to train a multi-layer Neural Networks whose inputs and outputs are designed to represent tactile information. The trained Neural Networks is used to regenerate the tactile sense on the virtual objects graphically made by a computer, and one can feel a quite similar sense of touch by using the system while touching the virtual objects.

• 한국정밀공학회지
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• 제20권2호
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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.

• International Journal of Control, Automation, and Systems
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• 제4권1호
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• pp.1-9
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• 2006

This paper presents the modeling and multivariable feedback control of a novel high-precision multi-dimensional positioning stage. This integrated 6-degree-of-freedom. (DOF) motion stage is levitated by three aerostatic bearings and actuated by 3 three-phase synchronous permanent-magnet planar motors (SPMPMs). It can generate all 6-DOF motions with only a single moving part. With the DQ decomposition theory, this positioning stage is modeled as a multi-input multi-output (MIMO) electromechanical system with six inputs (currents) and six outputs (displacements). To achieve high-precision positioning capability, discrete-time integrator-augmented linear-quadratic-regulator (LQR) and reduced-order linearquadratic-Gaussian (LQG) control methodologies are applied. Digital multivariable controllers are designed and implemented on the positioning system, and experimental results are also presented in this paper to demonstrate the stage's dynamic performance.

• 대한기계학회논문집A
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• 제33권6호
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• pp.607-613
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• 2009

In this paper, we made a simple paper feeding system which is one of MTS (media transport system) and controllers. The plant has a flexible paper and two driving rollers and two driven rollers. The control system has two conventional PID controllers. Skew angle and feeding speed of MTS deteriorate the quality of feeding system. In order to control a feeding speed and skew of feeding paper, we control rotational velocity of two driving rollers. Therefore, this controller has two inputs and two outputs as MIMO (multi-input and multi-output) system. The control inputs were the feeding speed and the skew displacement of the paper. The control outputs were the rotational velocity to each driving roller. To find appropriate PID gains of two controllers, we proposed an optimization technique. We assume the system variables and performance of a whole system as follows. PID gains of two controllers for skew and feeding speed are system variables. System performance is both skew and feeding speed. We simulates to making mathematical correlation using global Kriging interpolation. To find appropriate value of system variables, optimization method is simulation in sequence as following method. First, the optimization solver simulates with DOE (design of experiment) tables to find correlation equation of both system variable and performances. Then, the solver guesses the appropriate values and simulates if the system variables are appropriate or not. If the result of validation doesn't satisfy the convergence and iteration tolerance, the solver makes a new Kriging models and iterates this sequence until satisfy the tolerances.

• 전산구조공학
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• 제8권1호
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• pp.161-172
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• 1995

본 연구에서는 유한요소 구조해석을 위한 전후처리 통합운영 시스템을 개발하였다. 이 시스템은 구조해석, 전처리 및 후처리가 윈도우즈 환경에서 통합운영될 수 있도록 설계되었는데, 다중처리, 객체연결 및 결합 기법 등을 사용한 다중 윈도우상에서 대화식 입출력 기능과 여러가지 입출력 결과의 동시표현 등으로 더 향상된 그래픽 사용자 접속장치 환경을 제공한다. 따라서 메뉴, 대화상자, 다중 윈도우상에서의 단계별 자동입력 등을 통하여 자료의 입력이 용이해졌고, 동일 화면상에서 입력자료와 출력결과를 동시에 나타낼 수 있게 되었다. 본 시스템의 타당성과 효율성을 검증하기 위하여 여러가지 구조물에 대한 정적 및 자유진동해석을 수행하였다.

• 한국정밀공학회지
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• 제20권2호
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• pp.85-93
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• 2003

Generally, it is very difficult to get a modeling equation because multi-variable system has coupling relations between its inputs and outputs. To design an optimal controller without the modeling equation, this paper proposes a neural-network (NN) controller being learned by Jacobian matrix. Another major characteristic is that the controller consists of two separated NN controllers, namely, proportional control part and derivative control part. Simulation results for a catamaran system show that the proposed NN controller is superior to LQR in the regulation and tracking problems.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 봄 학술발표회 논문집
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• pp.170-175
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• 1995

In this paper, the problems on Windows application for finite element structural analysis softwares are presented. These Windows application programs provide the better graphical representation of structural geometry through the GUI, and provide the integrated environment for managing various processors such as a preprocessor and a postprocessor. Two examples show the efficiency of this system which can represent various inputs and outputs concurrently on multi-windows by dialog-type.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.265-273
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• 2016

A water wall system is one of the most important components of a boiler in a thermal power plant, and it is a nonlinear Multi-Input and Multi-Output (MIMO) system, with 6 inputs and 3 outputs. Three models are developed and comp for the controller design, including a linear model, a multilayer feed-forward neural network (MFNN) model and an Echo State Network (ESN) model. First, the linear model is developed by linearizing a given nonlinear model and is analyzed as a function of the operating point. Second, the MFNN and the ESN are developed by using training data from the nonlinear model. The three models are validated using Matlab with nonlinear input-output data that was not used during training.

• 제어로봇시스템학회논문지
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• 제3권2호
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• pp.187-196
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• 1997

This paper presents a semi-automatic methodology to synthesize executable digital controller saftware in a multi-loop control system. A digital controller is described by a task graph and end-to-end timing requirements. A task graph denotes the software structure of the controller, and the end-to-end requirements establish timing relationships between external inputs and outputs. Our approach translates the end-to-end requirements into a set of task attributes such as task periods and deadlines using nonlinear optimization techniques. Such attributes are essential for control engineers to implement control programs and schedule them in a control system with limited resources. In current engineering practice, human programmers manually derive those attributes in an ad hoc manner: they often resort to radical over-sampling to safely guarantee the given timing requirements, and thus render the resultant system poorly utilized. After task-specific attributes are derived, the tasks are scheduled on a single CPU and the compiled kernel is synthesized. We illustrate this process with a non-trivial servo motor control system.