• 로봇학회논문지
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• 제18권2호
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• pp.155-163
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• 2023

Auto Guided Vehicle (AGV) equipped with mecanum wheels can move in all directions, unlike ordinary wheeled AGVs. In this paper, we propose a robust trejectory tracking control method for the mecanum wheeled AGVs in the presence of disturbances. It is constructed by combining impedance control with Integral Sliding Mode Control (ISMC), which shows robust performance against disturbances, and adding a disturbance observer (DOB) that estimates and removes disturbances. Simulation result using MATLAB/SIMULINK shows that the proposed control method has robust performance in tracking the reference trajectory under the circumstance with disturbance. The control performance is further improved when the disturbance observer is additionally used. In addition, the performance of the proposed control method was verified through experiment. It shows the result of tracking the set trajectory well.

• 대한토목학회논문집
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• 제44권3호
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• pp.417-423
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• 2024

This study compared and analyzed the importance of command priority between railway traffic controllers through pairwise comparison of AHP analysis. 27 railway traffic controllers working on metropolitan railway control center, urban railway control center, and unmanned driving control center responded. As a result of the analysis, all the railway traffic controllers generally recognized the train driving control and train signal control as the most important priorities. For the controller in the manned driving system, a train driving control was the highest at 0.375. On the other hand, the controller based on unmanned driving recognized train signal control as the highest priority at 0.469. In the result of the AHP analysis considering all the variables, the braking system was the highest priority at 0.19 based on manned train driving. On the other hand, the controller based on unmanned train driving recognized wired and wireless network systems and SCADA as the highest priority at 0.267.

• Structural Engineering and Mechanics
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• 제52권5호
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• pp.919-935
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• 2014

In this study, the control of the shape of pre-stressed cable structures and the effective control element were examined. The process of deriving the displacement control equations using the force method was explained, and the concurrent control scheme (CCS) and the sequence control scheme (SCS) were proposed. To explain the control scheme process, the quadrilateral cable net model was adopted and classified into a regular model and an irregular model for the analysis of the control results. In the control analysis of the regular model, the CCS and SCS analysis results proved reliable. For the SCS, the errors occur in the control stage and varied according to the control sequence. In the control analysis of the irregular model, the CCS analysis result also proved relatively reliable, and the SCS analysis result with the correction of errors in each stage was found nearly consistent with the target shape after the control. Finally, to investigate an effective control element, the Geiger cable dome was adopted. A set of non-redundant elements was evaluated in the reduced row echelon form of a coefficient matrix of control equations. Important elements for shape control were also evaluated using overlapping elements in the element sets, which were selected based on cable adjustments.

• 한국해양공학회지
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• 제17권4호
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• pp.59-65
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• 2003

In order to achieve the desired lightweight and robust design of a structure, it is preferable to design a structure and its control system, simultaneously, which is termed the combined optimal design. A constant-cross-sectional area cantilever beam was chosen as the optimum design method, An initial load and a time-varying disturbance were applied at the free end of the beam. Sliding mode control was selected, due to its insensitivity to the disturbance, compared with other modes. It is known that the sliding mode control is robust to the disturbance and is uncertain, only if a matching condition is met, after giving a switching hyper plane. In this study, the optimum method was used for the design of the switching hyper plane, and the objective function of the optimum switching hyper plane was assumed to be the objective of the control system. The total weight of the structure was treated as a constraint, and the cross sectional areas of the beam were considered as design variables, the result being a nonlinear programming problem. To solve it, the sequential linear programming method was applied. As a result of the optimum design, the effect of attenuating vibrations has been substantially improved. Moreover, the lightweight design of the structure became possible as a result of the relationship of the weight of the structure to the control objective function.

• 한방안이비인후피부과학회지
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• 제33권2호
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• pp.83-99
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• 2020

Objectives : Atopic dermatitis is a chronic inflammatory skin disease with frequent relapses. This study was to investigate the effects of Gammakdaejo-tang(GMD) in DNCB induced atopic dermatitis mice. Methods : The study was divided into five comparion groups. 2,4-dinitrochlorobenzene(DNCB) solution was applied to Nc/Nga mice to induce atopic dermatitis, followed by normal group, negative control group with distilled water, positive control group with Dexamethasione and GMD 200mg/kg or 400mg/kg. The control group was orally administered 200㎕ once daily for 4 weeks. Visual skin condition, Immunoglobulin E, Histamine, Cytokine, Immune cells, Tissue biomarkers were observed. Results : As a result of the dermatitis score evaluation, it was confirmed that the GMD-administered group improved symptoms compared to the negative control group. As a result of measuring IgE, the GMD-administered group significantly decreased compared to the negative control group. As a result of measuring Histamine, GMD group except 200mg/kg of GMD significantly decreased compared to negative control group. As a result of measuring cytokine, GMD 200mg/kg significantly reduced IL-1β, IL-6 and TNF-α compared to the negative control. 400mg/kg significantly reduced IL-1β, IL-4, IL-5, IL-6, IL-10, TNF-α and significantly increased IL-2, IFNγ. As a result of confirming the immune cells, all experimental groups showed no difference in basophil, GMD group significantly reduced monocyte and eosinophil compared to negative control group, and GMD 400mg/kg group significantly reduced white blood cell and neutrophil. And significantly increased lymphocytes. As a result of measuring the gene expression level, all GMD group significantly increased TGF-β1 compared with the negative control group, and filaggrin, VEGF and EGF were significantly increased in GMD 400mg/kg group. Epidermis, dermis thickness, and eosinophil infiltration were found to be decreased in all GMD groups compared with the negative control group. Conclusions : GMD is effective in atopic dermatitis by reducing imbalance of immune response of T cells (Th1 / Th2) and reducing skin tissue damage and inflammatory response.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.139-139
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• 2000

The subject of this paper is the tole operation for unmanned vehicle. The aim is studied in context of motor control system and algorithms for the mid to low level control of tele operation unmanned vehicle described. Modern, vehicle related researches have been implemented about control, chassis, body and safe쇼 but now is to driving comfort, I.T.S. and human factor, etc. As a result of this fact, unmanned vehicle is main research topic over the world but it is still very expensive and unreasonable. A hierarchical approach is studied in context of motor control system and algorithms for the mid to low level control of tele operation unmanned vehicle described. The real time control and monitoring of longitudinal, lateral, Pitching motion is to be solved by system integration and optimization technique. We show the experimental result about fixed brake range test and acceleration test. And all system is to integrated for driving simulator and unmanned vehicle.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.973-974
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• 2006

In this paper, Computer-aided Maintenance Equipments, which are being used in maintenance, are applied to analyze failures in train control systems, resulting in long time delays of trains. It can be expected to extend and apply CAMS (Computer Aided Maintenance System) in the hereafter efficient operation and maintenance of high-speed railway train control systems, by comparison between the analysis result of fundamental causes, from high-speed railway train control system failures occurred during the operational process, and predictive result of failure causes, based on the recording data of CAMS when failures were occurred.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.75-80
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• 2003

Most of the control point surveying use a triangulation point and a bench mark with Total Station and Level. nowadays, the research is being accomplished for practical use of GPS. but In this study the optimum time and the optimum occupation time are analyzed, so as to examine possibility of the control point surveying that use GPS continuous station data of National Geography Institute. Also, The efficient surveying methods that compare the result of data that processed using broadcast ephemeris with the result of data that processed using precise ephemeris. As a result of that, Error feature analysis of the control point surveying in connection with GPS continuous observation will provide us estimation of errors and efficient topography information acquisition

• 전기학회논문지
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• 제56권9호
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• pp.1648-1654
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• 2007

In this paper, we consider the design of $H_\infty$ high-gain state feedback control for time-delayed linear systems with limited actuator capacities. The high-gain control means that the control permits the predetermined degree of saturation. Based on new Lyapunov-Krasovskii functional, we derive a result in the form of matrix inequalities. The matrix inequalities are consisted of LMIs those confirm the positive definiteness of Lyapunov- Krasovskii functional, satisfaction of predetermined degree of saturation, reachable set and $L_2$ gain constraint. The result is dependent on the bound of time-delay and its rate, predetermined degree of saturation, actuator capacity, and the allowed size of disturbances. Finally, we give a numerical example to show the effectiveness and usefulness of our result.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2010년도 춘계 종합학술대회 논문집
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• pp.272-273
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• 2010

마이크로프로세서 시스템의 키보드 버튼의 누름 결과를 기존의 입력 스캔 제어방법이 아닌 인터럽트 제어방법으로 시도하였다. 키보드 스캔 결과를 인터럽트 제어 방법으로 제어 시 적절한 30ms의 주기로 인식하도록 함으로써 마이크로프로세서의 작업부하를 줄이는 키보드 버튼 누름 제어 인식 알고리즘을 제시하였다.