• 한국항해항만학회지
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• 제33권1호
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• pp.1-7
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• 2009

항행속력규제는 통항안전성을 확보하기 위한 중요한 요소로서, 지금까지는 최고속력규제에 대하여만 연구 검토되어지고 있다. 최근 우리나라 항만에서는 중량물 운반용 예부선 등을 포함한 저속 항행선박으로 인하여 선박운항자의 위험부담감은 점점 증가하고 있다. 본 연구에서는 이러한 저속선박에 대한 최저속력 규제의 필요여부와 교통용량별 적정 최저속력을 산출하여 제안하였다. 이 연구의 구체적인 결과는 다음과 같다. (1) 시간당 통항척수가 5척의 경우에 최저속력을 5kts 이상으로 설정하면 속력규제 효과가 높다 (2) 시간당 통항척수가 10척 이상의 경우에 최저속력을 7kts로 설정하여야 속력규제 효과가 다소 있다 (3) 반면에, 통항척수가 많은 해역에서는 상대속력차가 적은 선박이 다수 발생하여, 선박 간 좁은 이격거리로 장시간 항행하여야 하므로 최저속력규제의 효과가 없는 것으로 판단된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2024-2029
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• 2005

In this paper, it is shown how a mobile robot can navigate with high speed in dynamic real environment. In order to achieve high speed and safe navigation, a robot collects environmental information. A robot empirically memorizes locations of high risk due to the abrupt appearance of dynamic obstacles. After collecting sufficient data, a robot navigates in high speed in safe regions. This fact implies that the robot accumulates location dependent environmental information and the robot exploits its experiences in order to improve its navigation performance. This paper proposes a computational scheme how a robot can distinguish regions of high risk. Then, we focus on velocity control in order to achieve high speed navigation. The proposed scheme is experimentally tested in real office building. The experimental results clearly show that the proposed scheme is useful for improving a performance of autonomous navigation. Although the scope of this paper is limited to the velocity control in order to deal with unexpected obstacles, this paper points out a new direction towards the intelligent behavior control of autonomous robots based on the robot's experience.

• 제어로봇시스템학회논문지
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• 제14권2호
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• pp.141-147
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• 2008

In this paper, we present one approach to achieve safe navigation in indoor dynamic environment. So far, there have been various useful collision avoidance algorithms and path planning schemes. However, those algorithms have a fundamental limitation that the robot can avoid only "visible" obstacles. In real environment, it is not possible to detect all the dynamic obstacles around the robot. There exist a lot of "occluded" regions due to the limitation of field of view. In order to avoid possible collisions, it is desirable to consider visibility information. Then, a robot can reduce the speed or modify a path. This paper proposes a safe navigation scheme to reduce the risk of collision due to unexpected dynamic obstacles. The robot's motion is controlled according to a hybrid control scheme. The possibility of collision is dually reflected to a path planning and a speed control. The proposed scheme clearly indicates the structural procedure on how to model and to exploit the risk of navigation. The proposed scheme is experimentally tested in a real office building. The presented result shows that the robot moves along the safe path to obtain sufficient field of view, while appropriate speed control is carried out.

• 산업경영시스템학회지
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• 제34권4호
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• pp.35-41
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• 2011

The purpose of this study was to examine drivers' driving behaviors and eye-movements according to driving speed and navigation- position while operation of the navigation in driving. For this purpose, two driving conditions (low-speed and high-speed) and two navigation-positions (top and bottom location of the center console) were set. Drivers' driving behaviors (speed, speed variation, coefficient of variation, and the number of collisions) and eye-movements (overall eye pattern, the average scanning time of navigation, and the number of gaze-out on the road for more 2 seconds) were measured. As a result, when the navigation was located at the bottom of the console, difficulties of lateral control was appeared in low-speed driving condition, and the that of longitudinal control was appeared in high-speed driving condition. In addition, above situation made the drivers' scanning times of navigation long, increased the number of gaze-out on the road for more 2 seconds, and made overall eye pattern monotonous. These results could be interpreted that the manipulation of the navigation at the bottom of console cause reduced attention capacity due to the cognitive load.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.29-29
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• 2000

This paper describes the design and implementation of a high-speed navigation computer to achieve precision navigation performance with Strapdown INS. The navigation computer inputs are velocity and angular increment data from the ISA at the signal of the 2404Hz interrupt and performs the removal of gyro block motion and the compensation of high dynamic errors at the 200Hz. For high-speed and high-accuracy, the computer consists of the 68040 micro-processor, 128k Memories, FPGAs, and so on. We show that the computer satisfies the required performance by In-Run navigation tests.

• 제어로봇시스템학회논문지
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• 제18권3호
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• pp.251-257
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• 2012

Unmanned ground vehicles have important military, reconnaissance, and materials handling application. Many of these applications require the UGVs to move at high speeds through uneven, natural terrain with various compositions and physical parameters. This paper presents a framework for high speed autonomous navigation based on the integrated real time traversability. Specifically, the proposed system performs real-time dynamic simulation and calculate maximum traversing velocity guaranteeing safe motion over rough terrain. The architecture of autonomous navigation is firstly presented for high-speed autonomous navigation. Then, the integrated real time traversability, which is composed of initial velocity profiling step, dynamic analysis step, road classification step and stable velocity profiling step, is introduced. Experimental results are presented that demonstrate the method for a $6{\times}6$ autonomous vehicle moving on flat terrain with bump.

• 제어로봇시스템학회논문지
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• 제7권9호
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• pp.774-782
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• 2001

In this paper, we propose a new approach to the autonomous and high-speed indoor navigation of wheeled mobile robots using hybrid system controller. The hierarchical structure of hybrid system presented consists of high-level reasoning process and the low-level motion control process and the environmental interaction. In a discrete event system, the discrete states are defined by the user-defined constraints and the reference motion commands are specified in the abstracted motions. The hybrid control system applied for the nonholonomic mobile robots can combine the motion planning and autonomous navigation with obstacle avoidance in the indoor navigation problem. For the evaluation of the proposed algorithm, the algorithm is implemented to the two-wheel driven mobile robot system. The experimental results show that the hybrid system approach is an effective method for the autonomous navigation in indoor environments.

• 해양환경안전학회지
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• 제20권2호
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• pp.193-201
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• 2014

본 연구는 강조류 해역을 통과하는 선박의 해양사고를 방지하기 위해 안전한 항행속력과 적절한 통과시기를 제시하였다. 이 자료의 해석을 위하여 2010년 7월 12일부터 15일까지 명량수도를 대상으로 통과선박의 AIS 데이터 수집과 2010년 9월 4일 현장조사를 실시하였고, 여기서 수집된 자료를 바탕으로 최소항행속력(minimum navigation speed)과 여유 제어력을 감안한 적정항행속력(optimum navigation speed), 조류속력별 대응타각(respond rudder angle)을 산출하였다. 또한 조위와 조류속력 데이터를 분석해 안전한 통과시기를 제시하였다. 이 연구를 통해 얻은 결과는 다음과 같다. (1) 조류의 유속이 4.4 kn 이상이 되면 선박의 타만으론 자력 조선이 불가능하다. (2) 강한 조류에 의해 발생되는 유압력과 회두모멘트에 대응하기 위해서는 최소항행속력은 조류의 2.3배, 적정항행속력은 조류의 4.0배 이상이어야 한다. (3)사리 기간 중 명량수도 적정 통과 시기는 고 저조시간 1시간 전부터 최소 30분 전까지이며 고 저조가 된 이후 5시간 동안은 4 kn 이상의 유속이 남아있는 시간으로 이 지역 항해를 자제해야 한다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.285-290
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• 2006

This paper presents an adaptive neural network based controller and its application to Dynamic Positioning (DP) control system of ship. The proposed neural network based controller is developed for station-keeping and low-speed maneuvering control of ship. At first, the DP system configuration is described. And then, to validate the proposed DP system, computer simulations of station-keeping and low-speed maneuvering performance of a multi-purpose supply ship are presented under the influence of measurement noise, external disturbances such as sea current, wave, and wind. The simulations have shown the feasibility of the DP system in various maneuvering situations.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 춘계학술발표회
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• pp.53-58
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• 2006

컨테이너 선박 및 고속선 동과 같이 고속인 선박의 등장으로 해상에서의 평균 통항 선박 속력은 이전보다 더욱 높아지고 있다. 그러나 우리나라의 특정해역으로 지정되어 있는 현행 교통 밀집해역에서의 속력규제는 수십년전의 규정으로 현재의 교통상황에 잘 부합되지 않는 제도라고 사료된다. 특히 그 해역을 항행하고 있는 선박운항자의 주장으로 인천항의 속력규제 폐지, 광양항의 속력규제 완화 등 속력규제에 관하여 논의가 계속되고 있지만 이러한 협수로에서의 속력규제에 대하여 수치화, 정량화한 연구는 드물다. 본 연구에서는 직선항로에서의 통항선박의 흐름을 재현한 후, 선박운항자의 선박운항 부담감을 정량화한 환경스트레스 모델 (ES Model)을 이용하여 속력규제에 대하여 분석하여 최대속력규제의 효과 여부에 대하여 알아보고자 한다.