• Transactions on Control, Automation and Systems Engineering
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• v.2 no.4
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• pp.274-284
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• 2000

In this paper, the design methodology of digital fuzzy controller(DFC) for the systems with time-delay is presented and the qualitative effects of the quantizers in digital implementation of a fuzzy controllers are investigated. We propose the fuzzy feed-back controller whose output is delayed with unit sampling period and period and predicted. the analysis and the design problem considering time-delay become very easy because the proposed controller is syncronized with the sampling time. The stabilization problem of the digital fuzzy system with time-delay is solved by linear matrix inequality(LMI) theory. Furthermore, we analyze the stability of the quantized fuzzy system. Our results prove that when quantization os taken into account, one only has convergence to some small neighborhood about origin. We develop a fuzzy control system for backing up a computer-simulated truck-trailer with the consideration of time-delay and quantization effect. By using the proposed method, we analyze the quantization effect to the system and design a DFC which guarantees the stability of the control system in the presence of time-delay.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.3
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• pp.189-194
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• 2002

This paper presents a state observer design for a class of MTMO nonlinear systems that has a block triangular structure. For this, the extension of the existing design for SISO triangular systems to MIMO cases is provided. Since the gain of the proposed observer. depends on a nonlinear part as well as a linear one of a system, it improves the transient performance of the high gain ob-server. Also, by using a generalized similarity transformation for the error dynamics, it is shown that order some boundedness condi-tion, the proposed observer guarantees the global exponential convergence of the estimation error. Finally, we will give a simulation example to show the validity of our design methodology.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.53-62
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• 2006

In this paper, ATM network congestion control with explicit rate feedback is considered. In ATM networks, delays commonly appear in data transmission and have to be considered in congestion control design. In this paper, a bounded single round delay on the return path is considered. Our objective is to design an explicit rate feedback control that achieves a robust optimal $H_2$ performance regardless of the bounded time-varying delays. An optimization approach in terms of linear matrix inequalities (LMIs) is given. Saturation in source rate and queue buffer is also taken into consideration in the proposed design. Simulations for the cases of single source and multiple sources are presented to demonstrate the effectiveness of the design.

• International Journal of Control, Automation, and Systems
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• v.2 no.3
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• pp.362-373
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• 2004

In this study, we introduce a noble neurogenetic approach to the design of the fuzzy controller. The design procedure dwells on the use of Computational Intelligence (CI), namely genetic algorithms and neurofuzzy networks (NFN). The crux of the design methodology is based on the selection and determination of optimal values of the scaling factors of the fuzzy controllers, which are essential to the entire optimization process. First, tuning of the scaling factors of the fuzzy controller is carried out, and then the development of a nonlinear mapping for the scaling factors is realized by using GA based NFN. The developed approach is applied to an inverted pendulum nonlinear system where we show the results of comprehensive numerical studies and carry out a detailed comparative analysis.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.199-208
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• 2009

Mosts of export/import cargo has been moving using maritime transport means. Korea had been driven the system automation project using EDI document since the mid-1990s. However, this automation system comes upon about 40-50% against overall maritime business process, manual or paper document processing work is existing as ever. International e-business environment also has changing into electronic form document transaction from paper document-based transaction. International standardization organization, UN/CEFACT proposed UNeDocs for paperless jtransaction. UNeDocs is a specification to define XML data model as well as electronic form. With UNeDocs, it is not necessary to generate the duplexed data, and it can support user convenient and guarantee the flexibility. This paper defines the UNeDocs data model for EDI and Off-Line processing at the current maritime business. Then, it have to check XML syntax and structure for the defined data model through quality of document check system. Also, it explains the applying plan about the defined UNeDocs data model. It is possible to support paperless transaction as defining UNeDocs-based standard data model and converting into paper document, XML and EDI document using UNeDocs data model.

• International Journal of Control, Automation, and Systems
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• v.5 no.3
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• pp.269-282
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• 2007

This paper presents a robust control method via the intelligent adaptive backstepping design technique for stable walking of nine-link biped robots with unknown model uncertainties and external disturbances. In our control structure, the self recurrent wavelet neural network(SRWNN) which has the information storage ability is used to observe the uncertainties of the biped robots. The adaptation laws for all weights of the SRWNN are induced from the Lyapunov stability theorem, which are used for on-line controlling biped robots. Also, we prove that all signals in the closed-loop adaptive system are uniformly ultimately bounded. Through computer simulations of a nine-link biped robot with model uncertainties and external disturbances, we illustrate the effectiveness of the proposed control system.

• Journal of Information Technology Application
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• v.2 no.1
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• pp.55-81
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• 2000

An Electronic Document Management System(EDMS) is an electronic system solution that is used to create, capture, distribute, edit, store and manage documents and related structured data repositories throughout an organization. Recently, documents of any type, such as text, images, and video files, and structured databases can be controlled and managed by an office automation system and an EDMS. Thus, many organizations are already using these information technologies to reduce process cycle-times. But what the organizations are missing is a integrated system the current workflow or office automation system and provides immediate access to and automatic routing of the organization's mission-critical information. This study tried to find out the user's requirements for integrating current information system and relatively new technology, electronic document management system in order to improve business operations, productivity and quality, and reduces waste. integration of electronic document management system(EDMS) and office automation system and proper use of these technological will improve organization's processes, and compress the process cycle-times. For this study a case study was done by a project team in cooperation with a government organization(say A company). Through this case study valuable electronic document management and office automation system requirement have been identified and reported for providing a system model in order to design an Integrated EDMS(IMDMS).

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.275-275
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• 2000

This paper designs a digital correlator for the integrated GPS/GLONASS receiver consisting of DCO, carrier cycle counter, code generator, code phase counter, mixer, epoch counter, accumulator. It is designed using Verilog-HDL(Verilog-Hardware Description Language) and synthesized using EDA(Electronic Design Automation) tools. The performance of the designed digital correlator is verified by the functional simulation and real satellite tracking experiments.

• International Journal of Control, Automation, and Systems
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• v.5 no.5
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• pp.559-569
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• 2007

In this paper, the dynamic controller design problem of a redundant planar 2-dof parallel manipulator is studied. Using the Euler-Lagrange equation, we formulate the dynamic model of the parallel manipulator in the joint space and propose an augmented PD controller with forward dynamic compensation for the parallel manipulator. By formulating the controller in the joint space, we eliminate the complex computation of the Jacobian matrix of joint angles with end-effector coordinate. So with less computation, our controller is easier to implement, and a shorter sampling period can be achieved, which makes the controller more suitable for high-speed motion control. Furthermore, with the combination of static friction model and viscous friction model, the active joint friction of the parallel manipulator is studied and compensated in the controller. Based on the dynamic parameters of the parallel manipulator evaluated by direct measurement and identification, motion control experiments are implemented. With the experiments, the validity of the dynamic model is proved and the performance of the controller is evaluated. Experiment results show that, with forward dynamic compensation, the augmented PD controller can improve the tracking performance of the parallel manipulator over the simple PD controller.

• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.411-418
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• 2005

This paper discusses an output-tracking control design method for Takagi-Sugeno fuzzy systems with parametric uncertainties. We first represent the concerned system as a set of uncertain linear systems. The tracking problem is then converted into a stabilization problem thereby leading to a more feasible control design procedure. A sufficient condition for robust practical output tracking is derived in terms of a set of linear matrix inequalities. A numerical example for a flexible-joint robot-arm model has been demonstrated, to convincingly show effectiveness of the proposed system modeling and control design.