• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.363-368
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• 2005

This paper proposes an LOS(line-of-sight) guidance system of a ship for path following. From the viewpoint of a control configuration, guidance is a special type of compensation algorithm that is placed in front of the controller to accomplish navigational objects. A guidance system generates a reference trajectory for trajectory tracking or path control and decides the desired velocity, position and heading angle. A control system executes commands based on a reliable guidance law during navigation. An LOS vector from the vessel to a point on the path between two way-points in straight-line navigation or a point among turning circle in turning navigation is selected, and then a heading angle is calculated to converge the desired path based on the LOS vector. The LOS guidance law is defined for the straight-line and the turning circle, respectively. The effectiveness of the suggested LOS guidance system is assured through computer simulation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.11
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• pp.898-906
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• 2014

This paper presents a reduction method for a straight-line path error of a flexible beam deploying from a rotating rigid hub. Previous studies discussed about only vibration phenomena of flexible beams deploying from rotating hubs; however, this study investigates a vibration reduction of a rotating beam with variable length. The equation of motion and associated boundary conditions are derived for a flexible beam deploying from a rotating rigid hub, and then they are transformed to a variational equation. By applying the Galerkin method, the discretized equations are obtained from the variational equation. Based on the discretized equations, the dynamic responses of a rotating/deploying beam are analyzed when the beam end has a straight line motion. A reduction method for the trajectory error is proposed, using the average length of a rotating/deploying beam. It is shown that the proposed method is able to reduce the residual vibration of a rotating/deploying beam.

• Journal of Information Processing Systems
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• v.14 no.6
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• pp.1457-1463
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• 2018

In recent times, Natural User Interface/Natural User Experience (NUI/NUX) technology has found widespread application across a diverse range of fields and is also utilized for controlling unmanned aerial vehicles (UAVs). Even if the user controls the UAV by utilizing the NUI/NUX technology, it is difficult for the user to easily control the UAV. The user needs an autopilot to easily control the UAV. The user needs a flight path to use the autopilot. The user sets the flight path based on the waypoints. UAVs normally fly straight from one waypoint to another. However, if flight between two waypoints is in a straight line, UAVs may collide with obstacles. In order to solve collision problems, flight records can be utilized to adjust the generated path taking the locations of the obstacles into consideration. This paper proposes a natural path generation method between waypoints based on flight records collected through UAVs flown by users. Bayesian probability is utilized to select paths most similar to the flight records to connect two waypoints. These paths are generated by selection of the center path corresponding to the highest Bayesian probability. While the K-means algorithm-based straight-line method generated paths that led to UAV collisions, the proposed method generates paths that allow UAVs to avoid obstacles.

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.1
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• pp.72-79
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• 1989

In this paper we consider the problem of finding an optimal straight line path of moving facility which interacts with a set of existing facilities fixed within a given rectangular area. We present a simple algorithm for rectilinear metric which greatly improves the pervious method and also propose algorithms for Euclidean and squared Euclidean distances.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10a
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• pp.882-885
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• 1987

The path of an industrial manipulator in a crowded workspace generally consists of 8 set of Cartesian straight line path connecting a set of two adjacent points. To achieve the Cartesian straight line path is, however, a nontrivial task and an alternative approach is to place enough intermediate points along a desired path and linearly interpolate between these points in the joint space. A method is developed that determines the subtravelling- and the transition-time such that the total travelling time for this path is minimized subject to the maximum joint velocities and accelerations constraint. The method is based on the application of nonlinear programming technique, i.e., FTM (Flexible Tolerance Method). These results are simulated on a digital computer using a six-joint revolute manipulator to show their applications.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.12-21
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• 2013

This study developed searching network reduction algorithm for reduce shortest path searching time. Developed algorithm is searching nodes that have the including possibility of less weights path than temporal path that consists minimum number of nodes and minimum sum of the straight line distances. The node that has the including possibility of shortest path is the node that the sum of straight line distance from start node and straight line distance to target node is less than the value that temporary path's weights divided by minimum weights units. If searching network reconstitutes only these nodes, the time of shortest path searching will be reduced. This developed algorithm has much effectiveness that start node and target node is close in large network.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.124-131
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• 2005

This paper suggests LOS(Line-Of-Sight) guidance system of a surface vessel in straight-line navigation under ocean currents An LOS vector from the vessel to a point on the path between two way-points is decided and a heading angle is calculated to converge to follow the desired path based on the LOS vector This guidance system is called LOS guidance system. The suggested LOS guidance law has parameters to be properly chosen according to navigational environment. Parameters of LOS guidance system are optimized to reduce propulsive energy and/or position error between desired Position and present position of a ship using genetic algorithm which is a strong optimization algorithm with adaptational random search The effectiveness of the suggested LOS guidance system is assured through computer simulations.

• Physical Therapy Rehabilitation Science
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• v.8 no.3
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• pp.141-145
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• 2019

Objective: The purpose of this study was to compare walking conditions (straight line and curved path) on walking patterns in persons who had experienced hemiplegic stroke and to determine whether if they adapt their walking pattern and performances according to changes in environmental conditions. Design: Cross-sectional study. Methods: Forty-four hemiplegic stroke survivors participated in this study. This study measured walking performance in three different walking conditions, such as straight walking, the more-affected leg in the inner curve walking, and less-affected leg in the inner curve walking conditions, and a 2-dimentional gait analysis system was used as a primary measurement. This study also measured secondary clinical factors including the Timed Up-and-Go Test, the Trunk Impairment Scale, and the Dynamic Gait Index. Results: After analyzing, cadence and step length of the less-affected side, stride length in the more-affected side, and stride length in less-affected side were significantly different among the three different walking conditions in this study (p<0.05), but other temporospatial parameters were not significant. Cadence was the largest in the straight walking condition. Step length in the less-affected side, stride length in the more-affected side, and stride length in less-affected side were also the longest in the straight walking condition. Conclusions: The results of the study suggest that hemiplegic stroke survivors show walking adaptability according to changes in walking demands and conditions, and moreover, cadence and step and stride lengths were significantly different between straight and curved walking conditions.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.125-134
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• 2006

The problem of establishing the servo system to reach the desired location keeping all features in the field of view and following a straight line is considered. In addition, robustness of camera calibration parameters is considered in this paper. The proposed approach is based on switching from position-based visual servoing (PBVS) to image-based visual servoing (IBVS) and allows the camera path to follow a straight line. To achieve the objective, a pose estimation method is required; the camera's target pose is estimated from the obtained images without the knowledge of the object. A switched control law moves the camera equipped to a robot end-effector near the desired location following a straight line in Cartesian space and then positions it to the desired pose with robustness to camera calibration error. Finally simulation results show the feasibility of the proposed visual servoing technique.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.2
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• pp.114-119
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• 2004

By Article two of a Japanese urban park low, it prescribes park facilities strictly, and one of the classifications includes 'path and plaza'. In addition, it is assumed that we divide several kinds different paths of width by size of the park in a path design of a park with a textbook of park design in a trunk line path, the main path, a vice-path or a branch path and design it. From such a thing, in the path of an urban park, a line consists straight of fixed width, and it is most that one pattern is considered to be. Therefore, in modem urban park, a path and division of a plaza are lucid explanation. It is rare that the historical parks which generally former daimyo gardens are shown later, and is used as a kind of an urban park width of the path where was particularly posted in a strolling garden in that is fixed, and width waits straight for even a line and waits, and, for this, there is. As a result, it is a path and the situation that are hard to be distinguished of a plaza. Although there are a difference of design and a difference of pavement materials in modem landscape space when We watch road surface constitution of the path that We did that will let you wait, in gross We are uniform, and it is it with a result to be poor in change nature. From such an observation, this consideration compared traditional landscape space and modem landscape space with path width about two points of road surface constitution through the trial that a graph analyzed the actual place data which measured into and lectured on an ideal method of a park path from this.