• 한국융합학회논문지
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• 제9권11호
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• pp.45-51
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• 2018

자율운항선박은 제4차 산업혁명을 맞이하여 조선해양분야에서 가장 주목을 받고 있는 기술이다. 특히, 자율운항선박기술은 해상에서의 안전성, 신뢰성, 효율성 및 친환경을 달성할 수 있는 핵심기술로서 간주되고 있다. 자율운항선박의 실현을 위해서는 선박이 자유적으로 운항할 수 있는 기술 뿐 아니라, 육상에서 원격으로 선박을 제어할 수 있는 기술도 중요하다. 본 논문에서는 육상에서 다양한 선박을 원격에서 관제할 수 있는 육상관제시스템에 대해서 다루고 있다. 본 논문에서는 원격관제를 위한 개방형 자율운항 시스템 구조로서 육상과 선박간 원격과제 및 원격 모니터링을 수행하기 위한 표준화된 원격관제 프로토콜과 선박 제어방안을 제안하고 있다. 또한, 본 논문에서는 모의선박을 통한 테스트베드 구축과 원격제어 기능에 대한 테스트를 통해 제안된 시스템의 적합성을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.45-45
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• 2000

This paper proposes a remote control system that combines computer network and an autonomous mobile robot. We control remotely an autonomous mobile robot with vision via the internet to guide it under unknown environments in the real time. The main feature of this system is that local operators need a World Wide Web browser and a computer connected to the internet communication network and so they can command the robot in a remote location through our Home Page. The hardware architecture of this system consists of an autonomous mobile robot, workstation, and local computers. The software architecture of this system includes the server part for communication between user and robot and the client part for the user interface and a robot control system. The server and client parts are developed using Java language which is suitable to internet application and supports multi-platform. Furthermore, this system offers an image compression method using motion JPEG concept which reduces large time delay that occurs in network during image transmission.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.181-183
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• 1986

This paper describes the concept of ADS (Autonomous Decentralized System) and its application to FA (Factory Automation). The schemes of ADFAS (Autonomous Decentralized Factory Automation System) utilizing these concepts are presented.

• 제어로봇시스템학회논문지
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• 제6권7호
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• pp.586-593
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• 2000

In this paper we propose a new approach to the autonomous wall-following of wheeled mobile robots using hybrid system reference motion synthesis and generation. The hybrid system approach is in-troduced to the motion control of nonholonomic mobile robots for the indoor navigation problems. In the dis-crete event system the discrete states are defined by the user-defined constraints and the reference mo-tion commands are specified in the abstracted motions. The hybrid control system applied for the non-holonomic mobile robots can combine the motion planning and autonomous navigation with obstacle avoid-ance for the indoor navigation problem. Simulation results show that hybrid system approach is an effective method for the autonomous navigation in indoor environments.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권6호
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• pp.674-682
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• 2003

선박 자율운항시스템(autonomous navigation system)이란 선박운항에 있어 항해계획을 수립하고 현재의 선박운항 상태를 파악하여 주변 상황변화를 예측하고 대처하는 항해 전문가의 능력을 전산화한 것이다. 선박 자율운항시스템은 항해, 충돌회피, 선체유지, 자료융합, 운동제어 그리고 이를 통합하는 아키텍처로 구성되어 있다. 운동제어시스템은 선박의 유체학적 특성을 고려하여 해도 상에 원하는 위치로 선박을 이동하기 위해서 추진 및 조타장치를 제어하는 시스템으로 자율운항제어시스템에 필수적인 구성 시스템 중에 하나이다. 본 논문은 운영플랫폼인 가상세계시스템을 기반으로 운영되는 선박자율운항시스템과 운동제어시스템의 연동과 구현에 관한 연구이다. 운동제어시스템은 충돌회피시스템으로부터 상위 레벨의 고수준제어 요구치를 전달받아 조타 및 추진치로 변환하고 조타장치와 추진장치를 제어하는 시스템이다. 본 논문에서 선박 운동 특성을 수학적으로 모방하는 Oldenburger의 제어 이론에 기반하여 선박운동제어기를 개발하고 성능검정을 위해 선박시뮬레이터에서 다양한 시나리오를 바탕으로 시뮬레이션 한다.

• ETRI Journal
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• 제37권3호
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• pp.617-625
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• 2015

In this paper, a steering control system for the path tracking of autonomous vehicles is described. The steering control system consists of a path tracker and primitive driver. The path tracker generates the desired steering angle by using the look-ahead distance, vehicle heading, and a lateral offset. A method for applying an autonomous vehicle to path tracking is an advanced pure pursuit method that can reduce cutting corners, which is a weakness of the pure pursuit method. The steering controller controls the steering actuator to follow the desired steering angle. A servo motor is installed to control the steering handle, and it can transmit the steering force using a belt and pulley. We designed a steering controller that is applied to a proportional integral differential controller. However, because of a dead band, the path tracking performance and stability of autonomous vehicles are reduced. To overcome the dead band, a dead band compensator was developed. As a result of the compensator, the path tracking performance and stability are improved.

• Journal of Biosystems Engineering
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• 제25권4호
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• pp.301-310
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• 2000

An autonomous tractor system was developed and its performance was evaluated. The system consisted of a tractor system of and a remote control station. The tractor and the remote control station communicated each other via wireless modems. The tractor had a DGPS(differential global positioning system), sensors, a controller and a modem. The DGPS collected position data and the tractor status was estimated. The information of tractor status and sensors was transferred to the remote control station. Then, the control station determined the control data such as steering angles using a fuzzy controller. The fuzzy controller used the information from the DGPS, sensors, and GIS(geographic information system) data. The control data were obtained by remote signal processing at the control station The control data for autonomous operation were transferred to the tractor controller. The performances of an autonomous tractor were evaluated for various speeds, different initial positions and different initial headings. About 1.3 seconds of time lag was occurred in transferring the tractor status data and the control data. Compensation the time lag, about 27cm deviation was observed at the speed of 0.5m/s and 37cm at the speed of 1m/s. Error caused mainly by the time lag and it would be reduced by developing a full-duplex radio module for controlling the remote tractor.

• 대한임베디드공학회논문지
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• 제6권5호
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• pp.303-309
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• 2011

In this paper, an intelligent force control technique is applied to an autonomous helicopter. Although most research on the autonomous helicopter system is about navigation and control, force control of an autonomous helicopter system is quite new and not presented yet. After controlling the position of the helicopter by the LQR method, force control is applied. The adaptive impedance force control algorithm is introduced and tested to regulate the desired force under unknown location and stiffness of the environment. To compensate for uncertainty from outer disturbance, a neural network is added to form an intelligent force control framework. Simulation studies show that the proposed force control algorithm works well.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.898-904
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• 2010

Unmanned autonomous forklifts have a great potential to enhance the productivity of material handling in various applications because these forklifts can pick up and deliver loads without an operator and any fixed guide. There are, however, many technical difficulties in developing such forklifts including localization, map building, sensor fusion, control and so on. Implementation, which is often neglected, is one of practical issues in developing such an autonomous device. This is because the system requires numerous sensors, actuators, and controllers that need to be connected with each other, and the number of connections grows very rapidly as the number of devices grows. Another requirement on the integration is that the system should allow changes in the system design so that modification and addition of system components can be accommodated without too much effort. This paper presents a network-based distributed approach where system components are connected to a shared CAN network, and control functions are divided into small tasks that are distributed over a number of microcontrollers with a limited computing capacity. This approach is successfully applied to develop an unmanned forklift.

• 한국안전학회지
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• 제36권4호
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• pp.1-11
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• 2021

Piping systems comprising pumps and valves are essential in the power plant, oil, and defense industry. Their purpose includes a stable supply of the working fluid or ensuring the target system's safe operation. However, piping system accidents due to leakage of toxic substances, explosions, and natural disasters are prevalent In addition, with the limited maintenance personnel, it becomes difficult to detect, isolate, and reconfigure the damage of the piping system and recover the unaffected area. An autonomous recovery piping system can play a vital role under such circumstances. The autonomous recovery algorithms for the piping system can be divided into low-pressure control algorithms, hydraulic resistance control algorithms, and flow inventory control algorithms. All three methods include autonomous opening/closing logic to isolate damaged areas and recovery the unaffected area of piping systems. However, because each algorithm has its strength and weakness, appropriate application considering the overall design, vital components, and operating conditions is crucial. In this regard, preliminary research on algorithm's working principle, its design procedures, and expected damage scenarios should be accomplished. This study examines the characteristics of algorithms, the design procedure, and working logic. Advantages and disadvantages are also analyzed through simulation results for a simplified piping system.