• Title/Summary/Keyword: Path-Based Algorithm

Search Result 1,390, Processing Time 0.025 seconds

A Novel Multi-Path Routing Algorithm Based on Clustering for Wireless Mesh Networks

  • Liu, Chun-Xiao;Zhang, Yan;Xu, E;Yang, Yu-Qiang;Zhao, Xu-Hui
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.8 no.4
    • /
    • pp.1256-1275
    • /
    • 2014
  • As one of the new self-organizing and self-configuration broadband networks, wireless mesh networks are being increasingly attractive. In order to solve the load balancing problem in wireless mesh networks, this paper proposes a novel multi-path routing algorithm based on clustering (Cluster_MMesh) for wireless mesh networks. In the clustering stage, on the basis of the maximum connectivity clustering algorithm and k-hop clustering algorithm, according to the idea of maximum connectivity, a new concept of node connectivity degree is proposed in this paper, which can make the selection of cluster head more simple and reasonable. While clustering, the node which has less expected load in the candidate border gateway node set will be selected as the border gateway node. In the multi-path routing establishment stage, we use the intra-clustering multi-path routing algorithm and inter-clustering multi-path routing algorithm to establish multi-path routing from the source node to the destination node. At last, in the traffic allocation stage, we will use the virtual disjoint multi-path model (Vdmp) to allocate the network traffic. Simulation results show that the Cluster_MMesh routing algorithm can help increase the packet delivery rate, reduce the average end to end delay, and improve the network performance.

Thompson sampling based path selection algorithm in multipath communication system (다중경로 통신 시스템에서 톰슨 샘플링을 이용한 경로 선택 기법)

  • Chung, Byung Chang
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.25 no.12
    • /
    • pp.1960-1963
    • /
    • 2021
  • In this paper, we propose a multiplay Thompson sampling algorithm in multipath communication system. Multipath communication system has advantages on communication capacity, robustness, survivability, and so on. It is important to select appropriate network path according to the status of individual path. However, it is hard to obtain the information of path quality simultaneously. To solve this issue, we propose Thompson sampling which is popular in machine learning area. We find some issues when the algorithm is applied directly in the proposal system and suggested some modifications. Through simulation, we verified the proposed algorithm can utilize the entire network paths. In summary, our proposed algorithm can be applied as a path allocation in multipath-based communications system.

3D A*-based Berthing Path Planning Algorithm Considering Path Following Suitability (경로 추종 적합성 고려 3D A* 기반 접안 경로 계획 알고리즘 개발)

  • Yeong-Ha Shin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2022.11a
    • /
    • pp.351-356
    • /
    • 2022
  • Among the path planning methods used to generate the ship's path, the graph search-based method is widely used because it has the advantage of its completeness, optimality. In order to apply the graph-based search method to the berthing path plan, the deviation from the path must be minimized. Path following suitability should be considered essential, since path deviation during berthing can lead to collisions with berthing facilities. However, existing studies of graph search-based berthing path planning are dangerous for application to real-world navigation environments because they produce results with a course change just before berthing. Therefore, in this paper, we develop a cost function suitable for path following, and propose a 3D A* algorithm that applies it. In addition, in order to evaluate the suitability for the actual operating environment, the results of the path generation of the algorithm are compared with the trajectory of the data collected by manned operations.

  • PDF

Analog Celluar Nonlinear Circuits-Based Dynamic Programming with Subgoal Setting (서브 골 설정에 의한 아날로그 셀룰라 비선형 회로망 기반 동적계획법)

  • Kim, Hyong-Suk;Park, Jin-Hee;Son, Hong-Rak;Lee, Jae-Chul;Lee, Wang-Hee
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.49 no.10
    • /
    • pp.582-590
    • /
    • 2000
  • A fast optimal path planning algorithm using the analog Cellular Nonlinear Circuits(CNC) is proposed. The analog circuits based optimal path planning is very useful since most of the optimal path planning problems require real time computation. There has already been a previous study to implement the dynamic programming with analog circuits. However, it could not be applied for the practically large size of problems since the algorithm employs the mechanism of reducing its input current/voltage by the amount of cost, which causes outputs of distant cells to become zero. In this study, a subgoal-based dynamic programming algorithm to compute the optimal path is proposed. In the algorithm, the optimal paths are computed regardless of the distance between the starting and the goal points. It finds subgoals starting from the starting point when the output of the starting cell is raised from its initial value. The subgoal is set as the next initial position to find the next subgoal until the final goal is reached. The global optimality of the proposed algorithm is discussed and two different kinds of simulations have been done for the proposed algorithm.

  • PDF

Path Planning Based on Spline D* for Mobile-robot (이동로봇을 위한 스플라인 D* 기반의 경로 계획)

  • Ryu, Hee-Rack;Choi, Yun-Won;Saitov-Sinl, Dilshat;Lee, Suk-Gyu
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.63 no.1
    • /
    • pp.92-98
    • /
    • 2014
  • This paper proposes a hermite spline based D* algorithm for effective path planning of mobile robot to improve the detecting speed. In conventional path planning research, a robot is supposed to pass through predetermined centers of grid partitions of area. However it doesn't guarantee the optimal path during its navigation. In addition, a robot is hard to avoid obstacles effectively. The proposed algorithm in this paper makes use of stochastic characteristics of nonholonomic mobile robot and estimation of shortest path to curvature movement of the robot. The performance evaluation of the improved spline D* algorithm performed through simulation shows its effectiveness. Moreover, the experiment verifies that a robot can find the shortest path by building the curve paths while it is moving on the path in spline.

Design and Implementation of a friendly maze program for early childhood based on a path searching algorithm

  • Yun, Unil;Yu, Eun Mi
    • Journal of the Korea Society of Computer and Information
    • /
    • v.22 no.6
    • /
    • pp.49-55
    • /
    • 2017
  • Robots, games and life applications have been developed while computer areas are developed. Moreover, various applications have been utilized for various users including the early childhood. Recently, smart phones have been dramatically used by various users including early childhood. Many applications need to find a path from a starting point to destinations. For example, without using real maps, users can find the direct paths for the destinations in realtime. Specifically, path exploration in game programs is so important to have accurate results. Nowadays, with these techniques, diverse applications for educations of early childhood have been developed. To deal with the functions, necessity of efficient path search programs with high accuracy becomes much higher. In this paper, we design and develop a friendly maze program for early childhood based on a path searching algorithm. Basically, the path of lineal distance from a starting location to destination is considered. Moreover, weight values are calculated by considering heuristic weighted h(x). In our approach, A* algorithm searches the path considering weight values. Moreover, we utilize depth first search approach instead of breadth first search in order to reduce the search space. so it is proper to use A* algorithm in finding efficient paths although it is not optimized paths.

Improving the Performance of AODV(-PGB) based on Position-based Routing Repair Algorithm in VANET

  • Jung, Sung-Dae;Lee, Sang-Sun;Oh, Hyun-Seo
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.4 no.6
    • /
    • pp.1063-1079
    • /
    • 2010
  • Vehicle ad hoc networks (VANET) are one of the most important technologies to provide various ITS services. While VANET requires rapid and reliable transmission, packet transmission in VANET is unstable because of high mobility. Many routing protocols have been proposed and assessed to improve the efficiency of VANET. However, topology-based routing protocols generate heavy overhead and long delay, and position-based routing protocols have frequent packet loss due to inaccurate node position. In this paper, we propose a position-based routing repair algorithm to improve the efficiency of VANET. This algorithm is proposed based on the premise that AODV (-PGB) can be used effectively in VANET, if the discovery, maintenance and repair mechanism of AODV is optimized for the features of VANET. The main focus of this algorithm is that the relay node can determine whether its alternative node exits and judge whether the routing path is disconnected. If the relay node is about to swerve from the routing path in a multi-hop network, the node recognizes the possibility of path loss based on a defined critical domain. The node then transmits a handover packet to the next hop node, alternative nodes and previous node. The next node repairs the alternative path before path loss occurs to maintain connectivity and provide seamless service. We simulated protocols using both the ideal traffic model and the realistic traffic model to assess the proposed algorithm. The result shows that the protocols that include the proposed algorithm have fewer path losses, lower overhead, shorter delay and higher data throughput compared with other protocols in VANET.

A collision-free path planning using linear parametric curve based on circular workspace geometry mapping (원형작업공간의 기하투영에 의한 일차 매개 곡선을 이용한 충돌회피 궤적 계획)

  • 남궁인
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1996.10b
    • /
    • pp.896-899
    • /
    • 1996
  • A new algorithm for planning a collision free path is developed based on linear parametric curve. A collision-free path is viewed as a connected space curve in which the path consists of two straight curve connecting start to target point. A single intermediate connection point is considered in this paper and is used to manipulate the shape of path by organizing the control point in polar coordinate (.theta.,.rho.). The algorithm checks interference with obstacles, defined as GM (Geometry Mapping), and maps obstacles in Euclidean Space into images in CPS (Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The clear area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidean Space. Any points from the clear area of CPS is a candidate for a collision-free path. A simulation of GM for number of cases are carried out and results are presented including mapped images of GM and performances of algorithm.

  • PDF

Development of Path Tracking Algorithm and Variable Look Ahead Distance Algorithm to Improve the Path-Following Performance of Autonomous Tracked Platform for Agriculture (농업용 무한궤도형 자율주행 플랫폼의 경로 추종 및 추종 성능 향상을 위한 가변형 전방 주시거리 알고리즘 개발)

  • Lee, Kyuho;Kim, Bongsang;Choi, Hyohyuk;Moon, Heechang
    • The Journal of Korea Robotics Society
    • /
    • v.17 no.2
    • /
    • pp.142-151
    • /
    • 2022
  • With the advent of the 4th industrial revolution, autonomous driving technology is being commercialized in various industries. However, research on autonomous driving so far has focused on platforms with wheel-type platform. Research on a tracked platform is at a relatively inadequate step. Since the tracked platform has a different driving and steering method from the wheel-type platform, the existing research cannot be applied as it is. Therefore, a path-tracking algorithm suitable for a tracked platform is required. In this paper, we studied a path-tracking algorithm for a tracked platform based on a GPS sensor. The existing Pure Pursuit algorithm was applied in consideration of the characteristics of the tracked platform. And to compensate for "Cutting Corner", which is a disadvantage of the existing Pure Pursuit algorithm, an algorithm that changes the LAD according to the curvature of the path was developed. In the existing pure pursuit algorithm that used a tracked platform to drive a path including a right-angle turn, the RMS path error in the straight section was 0.1034 m and the RMS error in the turning section was measured to be 0.2787 m. On the other hand, in the variable LAD algorithm, the RMS path error in the straight section was 0.0987 m, and the RMS path error in the turning section was measured to be 0.1396 m. In the turning section, the RMS path error was reduced by 48.8971%. The validity of the algorithm was verified by measuring the path error by tracking the path using a tracked robot platform.

A Path Tracking Control Algorithm for Autonomous Vehicles (자율 주행차량의 경로추종 제어 알고리즘)

  • 안정우;박동진;권태종;한창수
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.4
    • /
    • pp.121-128
    • /
    • 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.

  • PDF