• 한국정밀공학회지
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• 제12권7호
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• pp.32-45
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• 1995

In this paper, we present a new method to tool path planning problem for rough cut of pocket milling operations. The key idea is to formulate the tool path problem into a TSP (Travelling Salesman Problem) so that the powerful neural network approach can be effectively applied. Specifically, our method is composed of three procedures: a) discretization of the pocket area into a finite number of tool points, b) neural network approach (called SOM-Self Organizing Map) for path finding, and c) postprocessing for path smoothing and feedrate adjustment. By the neural network procedure, an efficient tool path (in the sense of path length and tool retraction) can be robustly obtained for any arbitrary shaped pockets with many islands. In the postprocessing, a) the detailed shape of the path is fine tuned by eliminating sharp corners of the path segments, and b) any cross-overs between the path segments and islands. With the determined tool path, the feedrate adjustment is finally performed for legitimate motion without requiring excessive cutting forces. The validity and powerfulness of the algorithm is demonstrated through various computer simulations and real machining.

• 한국항공운항학회지
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• 제24권1호
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• pp.1-9
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• 2016

In this paper, we integrate three degree of freedom(3DOF) point-mass model for aircraft and three-dimensional path generation algorithms using dubins curve and nonlinear path tracking law. Through this integration, we apply the path generation algorithm to the path planning, and verify tracking performance and feasibility of using the aircraft 3DOF point-mass model for air traffic management. The accuracy of modeling 6DOF aircraft is more accurate than that of 3DOF model, but the complexity of the calculation would be raised, in turn the rate of computation is more likely to be slow due to the increase of degree of freedom. These obstacles make the 6DOF model difficult to be applied to simulation requiring real-time path planning. Therefore, the 3DOF point-mass model is also sufficient for simulation, and real-time path planning is possible because complexity can be reduced, compared to those of the 6DOF. Dubins curve used for generating the optimal path has advantage of being directly available to apply path planning. However, we use the algorithm which extends 2D path to 3D path since dubins curve handles the two dimensional path problems. Control law for the path tracking uses the nonlinear path tracking laws. Then we present these concomitant simulation results.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제2호
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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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.142-147
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• 1988

Free-path-type guidance system does not need a hardwired path in the environment so that it gives a mobile robot a flexible path. ln this study to achieve the free-path-type guidance system for a mobile robot which is steered by the differential steering of both drive forewheels, position recognition systems are constructed using odometer system as an internal position sensor. Two odometer systems, a auxiliary wheel odometer and a 2-encoder odometer system are constructed and path following algorithms using these odometer systems are designed and experimented. PID control type is adopted in the path following algorithms.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.31-34
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• 2000

In this paper, we design an optimal path for multiple mobile robots. For this purpose, we propose a new method of path planning for multiple mobile robots in dynamic environment. First, every mobile robot searches a global path using a distance transform algorithm. Then we put subgoals at crooked path points and optimize them. And finally to obtain an optimal on-line local path, ever)r mobile robot searches a new path with static and dynamic obstacle avoidance.

• 대한교통학회지
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• 제22권4호
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• pp.135-146
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• 2004

교통정보에 의한 교통량분산 효과를 실질적으로 얻기 위해서는 좌회전금지, U-turn, P-turn과 같은 교차로내 회전제약이 존재하는 일반 가로망에서 적정수의 경로를 도출하여 제공해야 한다. 이를 위하여 k-path 알고리듬이 주로 이용되고 있으나 도출된 경로들간에 중복성이 문제가 되고 있다. 본 연구는 교차로내 회전제약들을 고려하면서 교통정보제공을 위한 n개의 최단경로탐색(n-path) 알고리듬을 개발하는 데 연구의 목적이 있다 여기서 n-path 알고리듬은 기존 k-path 알고리듬과는 차이가 있는데, k-path 알고리듬은 기종점간 통행비용을 기초로 첫 번째 최단경로외 2번째 최단경로, 3번째 최단경로,....식으로 k개의 최단경로를 찾는 데 비해, n-path 알고리듬은 각 경로간 일정수준 이상의 경로중첩(path overlap)이 발생하지 않도록 하면서 n개의 경로를 탐색하는 방법이다. 이를 위하여 첫 번째 탐색된 경로를 중심으로 통행비용과 경로중복수준을 판단하여 이후 경로들을 탐색하게 된다. 또한, 본 연구에서 제시하는 n-path 알고리듬은 기존 연구와는 달리 교차로상 회전제약을 반영하기 위하여 가로망을 확장할 필요가 없다는 장점이 있다. 개발된 알고리듬을 몇 개의 예제 네트워크에 적용하여 평가하였으며 평가결과 원하는 결과를 도출하고 있음을 확인할 수 있었다.

• 한국지능시스템학회:학술대회논문집
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• 한국지능시스템학회 2007년도 추계학술대회 학술발표 논문집
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• pp.176-179
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• 2007

In this paper, we develop the path planning algorithm using the improved Dijkstra algorithm and the particle swarm optimization. To get the optimal path, at first we construct the MAKLINK on the world environment and then make a graph associated with the MAKLINK. From the graph, we obtain the Dijkstra path between the starting point and the destination point. From the optimal path, we search the improved Dijkstra path using the graph. Finally, applying the particle swarm optimization to the improved Dijkstra path, we obtain the optimal path for the mobile robot. It turns out that the proposed method has better performance than the result in [1].

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1496-1499
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• 2004

In this paper, we deal with a novel path planning algorithm to find collision-free path for a moving robot to find an appropriate path from initial position to goal position. The robot should make progress by avoiding obstacles located at unknown position. Such problem is called the path planning. We propose so called the subgoal generation algorithm to find an effective collision-free path. The generation and selection of the subgoal are the key point of this algorithm. Several subgoals, if necessary, are generated by analyzing the map information. The subgoal is the candidate for the final path to be pass through. Then selection algorithm is executed to choose appropriate subgoal to construct a correct path. Deep and through explanations are given for the proposed algorithm. Simulation example is given to show the effectiveness of the proposed algorithm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.301-305
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• 2001

Conventionally, robot control algorithms are divided into two stages, namely, path or trajectory planning and path tracking(or path control). This division has been adopted mainly as a means of alleviating difficulties in dealing with complex, complex, coupled manipulator dynamics. The minimum-time manipulator control problem is solved for the case when the path is specified and the actuator torque limitations are known. In path planning, DP is applied to applied to find the shortest path form initial position to final position with the assumptions that there is no obstacle and that each path is straight line. In path control, the phase plane technique is applied to the minimum-time control with the assumptions that the bound on each actuator torque is a function of joint position and velocity or constant. This algorithm can be used for any manipulator that has rigid link, known dynamics equations of motion, and joint angles that can be determined at a given position on the path.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.184-186
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• 2006

We propose a new method for shortest path planning of mobile robots. The topological information of the graph is obtained by thinning method to generate the collision-free path of robot. And the travelling path is determined through hierarchical planning stages. The first stage generates an initial path by use of Dijkstra's algorithm. The second stage then generates the final path by use of dynamic programming (DP). The DP adjusts the intial path to reduce the total travelling distance of robot. Simulation results are presented to verify the performance of the proposed method.