• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.2045-2050
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• 2008

The Autonomous station control system by applying the concepts of autonomous decentralized system is a system which can solve the problems of the current central control system. The Autonomous station control system tester developed in order to test for Autonomous station control system. The main function of tester is a time-deadline test, a schedule broadcast test, a route control test and a version-up test, etc. In the paper, we build the reliability of the Autonomous station control system by testing the Autonomous station control system tester. Also, the test enable the on-line test without the system interruption and verify the function of the Autonomous station control system developed by applying the concepts of Autonomous decentralized system to the current Central control system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1239-1243
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• 2007

Autonomous Station Control System is automatic route control system of large-scale station. The system has flexibility of system step-by-step construction and expandability. A method of step-by-step construction for Autonomous Station Control System has system expansion and subsystem software expansion. The system has autonomous controllability and autonomous coordinability for system step by step construction. With property for a basis, each of subsystem communicates data field. Also, Each subsystem has its own management system, Autonomous Data Manager to manage itself and coordinate with the others. This paper make clear test method for Autonomous Station Control System expansion and software expansion. The first test method of system increasing construction is single station construction test. The second of method is connecting test the neighbor's Autonomous Station Control System. The third of method is connecting test the Autonomous Line Management System. Also, the test method of software expansion take the case of route control subsystem.

• 수산해양기술연구
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• 제55권2호
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• pp.172-180
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• 2019

In this study, a ship motion control system design method is introduced for autonomous ships. Some related research results and technologies for autonomous ships have already been developed and applied to testing ships. Recently, the Norwegian Maritime Authority and the Coastal Administration have signed an agreement and started to test autonomous ships in the defined area. Considering recent technology trends and background, in this paper, the authors also try to develop autonomous ship control technologies. In the designed control system, an observer is introduced to estimate unmeasurable system states. Based on the servosystem with state estimator, ship motion control experiment is performed to evaluate control performance using a model ship in water basin.

• 자동차안전학회지
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• 제12권1호
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• pp.15-25
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• 2020

This paper presents a longitudinal control algorithm for ensuring takeover time of autonomous vehicle using V2V communication. In the autonomous driving of more than level 3, autonomous systems should control the vehicles by itself partially. However if the driver's intervention is required for functional safety, the driver should take over the control reasonably. Autonomous driving system has to be designed so that drivers can take over the control from autonomous vehicle reasonably for driving safety. In this study, control algorithm considering takeover time has been developed based on computation method of takeover time. Takeover time is analysed by conditions of longitudinal velocity of preceding vehicle in time-velocity plane. In addition, desired clearance is derived based on takeover time. The performance evaluation of the proposed algorithm in this study was conducted using 3D vehicle model with actual driving data in Matlab/Simulink environment. The results of the performance evaluation show that the longitudinal control algorithm can control while securing takeover time reasonably.

• 융합신호처리학회논문지
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• 제4권4호
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• pp.58-65
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• 2003

기존의 횡 방향제어 알고리즘은 도로에서 발생할 수 있는 변수를 고려하여 알고리즘을 작성해야 했다. 이러한 제어 알고리즘을 작성하기 위해서는 주행해야 하는 도로에 따라 파라미터를 재조정해야 하는 문제와 대량의 계산이 요구되는 모델링 문제가 있었다. 본 논문에서는 지능적 횡 방향제어가 가능한 학습알고리즘에 관해 연구하였다. 학습알고리즘은 인공지능 알고리즘 중 자기구성 알고리즘을 사용하였으며 학습데이터는 도로의 특징점을 이용하였다. 컴퓨터를 이용한 시뮬레이션 결과 본 논문의 학습알고리즘에 의한 조향제어가 가능한 것을 알 수 있었고 실제로 주행이 가능한 자율이동로봇에 적용하여 학습에 의한 횡 방향제어가 가능한 것을 확인하였다.

• 한국정밀공학회지
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• 제17권4호
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• pp.121-128
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• 2000

In this paper, the control algorithm fur an autonomous vehicle is studied and applied to an actual 2 wheel-driven vehicle system. In order to control a nonholonomic system, the kinematic model for an autonomous vehicle is constructed by relative velocity relationship about the virtual point at distance from the vehicle's frame. And the optimal controller that based on the kinematic model is operated on purpose to track a reference vehicle's path. The actual system is designed with named 'HYAVI' and the system controller is applied. Because all the results of simulation don't satisfy the driving conditions of HYAVI, a reformed control algorithm that satisfies an actual autonomous vehicle is applied at HYAVI. At the results of actual experiments, the path tracking works very well by the reformed control algorithm. An autonomous vehicle that applied this control algorithm can be easily used for a path generation algorithm.

• 농업과학연구
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• 제37권1호
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• pp.123-130
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• 2010

A steering control system based on CAN(Controller Area Network) for autonomous tractor was developed to reduce duty of a central processing computer and to improve performance of steering control in terms of reduced control interval and error. The steering control system consisted of a SCU (Steering Control Unit), an EHPS system, and a potentiometer. The SCU consisted of an MCU (Micro Controller unit), an A/D converter, and a DC-DC converter, and a PID controller was used to control steering angle. The steering control system was communicated with the computer by CAN-bus. Each actuator and implement was connected to a multi-function board interfacing with the computer through a USB cable. Without CAN, control interval of the autonomous tractor was 1.5 seconds. When the CAN-based steering control system was combined with the autonomous tractor, however, control interval of the integrated system was reduced to those less than 0.05 seconds. When the autonomous tractor was operated with 1.5-s and 0.05-s control cycles at a 0.63-m/s travelling speed, the trajectories were close to straight lines for both of the control cycles. For a 1.34-m/s traveling speed, tractor trajectory was close to sine wave with a 1.5-s control cycle, but was straight line with a 0.05-s control cycle.

• 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.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.501-517
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• 2016

Synchronized switch damping (SSD) is a structural vibration control technique in which a piezoelectric patch attached to or embedded into the structure is connected to or disconnected from the shunt circuit in order to dissipate the vibration energy of the host structure. The switching process is performed by a digital signal processor (DSP) which detects the displacement extrema and generates a command to operate the switch in synchronous with the structure motion. Recently, autonomous SSD techniques have emerged in which the work of DSP is taken up by a low pass filter, thus making the whole system autonomous or self-powered. The control performance of the previous autonomous SSD techniques heavily relied on the electrical quality factor of the shunt circuit which limited their damping performance. Thus in order to reduce the influence of the electrical quality factor on the damping performance, a new autonomous SSD technique is proposed in this paper in which a negative capacitor is used along with the inductor in the shunt circuit. Only a negative capacitor could also be used instead of inductor but it caused saturation of negative capacitor in the absence of an inductor due to high current generated during the switching process. The presence of inductor in the shunt circuit of negative capacitor limits the amount of current supplied by the negative capacitance, thus improving the damping performance. In order to judge the control performance of proposed autonomous SSDNCI, a comparison is made between the autonomous SSDI, autonomous SSDNC and autonomous SSDNCI techniques for the control of an aluminum cantilever beam subjected to both single mode and multimode excitation. A value of negative capacitance slightly greater than the piezoelectric patch capacitance gave the optimum damping results. Experiment results confirmed the effectiveness of the proposed autonomous SSDNCI technique as compared to the previous techniques. Some limitations and drawbacks of the proposed technique are also discussed.

• 수산해양기술연구
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• 제54권3호
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• pp.231-238
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• 2018

In this study, a ship motion control system design method is introduced for autonomous ships. Some related research results and technologies for autonomous ships have already been developed and applied to ships. For example, the Norwegian Maritime Authority and the Coastal Administration have signed an agreement that allows to test of autonomous ships in the defined area (port to port). Many countries and industries are pursuing to realize the autonomous vessel in the real world. In this paper, the authors try to develop related technology. As basic research, a ship model of the pilot vessel is developed and physical parameters are identified by experiment and simulations. Using the mathematical ship model, a control system is designed and control performance is evaluated by simulations.