• Title/Summary/Keyword: 경로 안정성

Search Result 1,364, Processing Time 0.041 seconds

Autonomous Navigation Controller of Differential Drive Mobile Robots in Unknown Environments (불확실한 환경에서의 차륜 구동 이동 로봇의 자율 주행 제어기)

  • Yoon, Do-Young;Oh, Sang-Rok;Park, Gwi-Tae;Kim, Hwang-Bae
    • Proceedings of the KIEE Conference
    • /
    • 2003.07d
    • /
    • pp.2417-2419
    • /
    • 2003
  • 이동성에 nonholonomic 제약을 받는 차륜 구동 이동 로봇의 불확실한 환경에서의 자율 주행 제어기를 제안하였다. 전체 시스템은 on-line으로 지역경로 계획을 하는 planner 부분과 차륜 구동 이동 로봇의 nonholonomic 제약을 극복하면서 계획된 지역 경로를 충실히 추종하기 위한 제어기 부분의 두 부분으로 구성하였다. Planner는 빠른 응답을 생성하고, 전역적인 정보를 사용하지 않기 위하여 반사적인 제어 방식에 의한 경로 생성 방식을 채택하였고, 제어기 부분은 비선형 posture feedback stabilizer로 설계하였다. 제안된 시스템은 단순한 형태의 제어 방식으로 완전한 자율적인 판단에 의한 장애물 회피와 목표 지점으로의 수렴 능력을 보여 준다. 본 시스템의 단순하면서도 효과적인 자율주행 능력은 반사제어 방식의 장점과 feedback 제어기의 증명된 안정성에서 기인한다. 시뮬레이션과 자체 구현한 차륜 구동 이동 로봇인 "MARI"로 실제 환경에서의 실험을 실시하여 제안된 제어기의 유효성을 검증하였다.

  • PDF

A Three-Tier BGP Backup Routing (3단 BGP 백업 라우팅)

  • Suh, Chang-Jin
    • Journal of KIISE:Information Networking
    • /
    • v.32 no.6
    • /
    • pp.745-752
    • /
    • 2005
  • BGP is a unique routing protocol in broadband internet. It chooses routing paths considering internet hierarchy and local policies. As BGP routers selectively bypass routing information to a subset of neighboring BGP routers, connectivity by way of a series of links between source and destination nodes does not mean reachability of routing information of the two. In emergency when BGP routers or links over wide range are not available, BGP routers have to use links that are not normally used to keep reachability. This paper listed out the requirements for BGP backup routing and proposed a routing solution that hides most demerits in currently published ones. The proposed backup operates in three tiers according to network damage. Under this rule, BGP routers use tier-0 routing paths at normal. If networks are impaired, they choose tier-1 paths. If networks are seriously damaged, tier-2 paths are allowed to use. Also this paper proves that the proposed backup guarantees stability and safeness. As results, the proposed backup is very adaptive to light network damages as well as serious ones and provides strong routing reachability at all times.

Finding a Second Best Coverage Path (차선거리유지 경로찾기)

  • Na, Hyeon-Suk;Kim, Jung-Hee
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.35 no.8
    • /
    • pp.385-393
    • /
    • 2008
  • The best coverage problem is finding a path whose worst distance to the sensor-set is the best among all paths. Instead, if the user stays close to its nearest two sensors, then the stability of the wireless connection may be guaranteed. So we consider the problem of finding a second best coverage path; given the sensor set U, a starting point s and a target point t, find a path whose worst distance to the second closest sensor is minimized. This paper presents an O(n logn) -time algorithm to find such a path. We also give experimental evidence showing that the connection to the sensor-set along a second best coverage path is more stable than that along the best coverage path.

T-S Fuzzy Model Mobile Robot Trajectory Tracking Control using SOSTOOL (SOSTOOL을 이용한 T-S 퍼지모델 이동로봇의 경로추적 제어)

  • Kim, Cheol-Joong;Chwa, Dong-Kyoung;Hong, Suk-Kyo
    • Proceedings of the KIEE Conference
    • /
    • 2008.07a
    • /
    • pp.1519-1520
    • /
    • 2008
  • 이 논문에서는 이동로봇의 경로추적문제를 다항 퍼지 모델로 나타내고 SOSTOOL을 이용하여 해결하고자 한다. 제안하는 방법은 기존의 LMI을 사용한 방법과 비교하여 작은 제어입력과 이동로봇이 주어진 경로를 쫓아감에 있어 매끄러운 결과를 나타냄을 알 수 있다. 본 논문에서는 이동로봇 기구학을 시스템의 안정성 문제로 변형하고 이를 퍼지모델로 구성하여 SOSTOOL을 사용하여 제어입력을 구하고 모의실험을 통해 그 결과를 검증하도록 한다.

  • PDF

The performance evaluation of the throughput increasement according to the stable adaptive modulation to the mobile communication system (이동통신 시스템에 적용된 안정화 적응변조방식의 전송효율 성능분석)

  • 오의교;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.28 no.10A
    • /
    • pp.780-787
    • /
    • 2003
  • Adaptive modulation is the method to increase the throughput of the mobile system using the power margin of the system design. In this paper, we propose the method to change adaptive modulation parameters for the stable system operation by monitoring the mobility of the mobile station. The proposed method measures the instanteneous mobility of the mobile station monitoring the closed power control data. The MPSK modulation method is used for the basic modulation method because of the hardware implementation. Using the proposed method we can get the more powerful throughput. By the system simulation to verify the evaluation of the proposed algorithm, we can notice the algorithm is more efficient than the typical method

An Entropy-Based Routing Protocol for Supporting Stable Route Life-Time in Mobile Ad-hoc Wireless Sensor Networks (모바일 Ad-hoc 무선 센서 네트워크에서 안정된 경로의 Life-Time을 지원하기 위한 엔트로피 기반의 라우팅 프로토콜)

  • An, Beong Ku;Lee, Joo Sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.8 no.1
    • /
    • pp.31-37
    • /
    • 2008
  • In this paper, we propose an entropy-based routing protocol to effectively support both stable route construction and route lifetime in Mobile Ad-hoc Wireless Sensor Networks (MAWSN). The basic idea and feature of the proposed routing protocol are as follows. First, we construct the stable routing routes based on entropy concept using mobility of mobile nodes. Second, we consider a realistic approach, in the points of view of the MAWSN, based on mobile sensor nodes as well as fixed sensor nodes in sensor fields while the conventional research for sensor networks focus on mainly fixed sensor nodes. The performance evaluation of the proposed routing protocol is performed via simulation using OPNET(Optimized Network Engineering Tool) and analysis. The results of the performance evaluation show that the proposed routing protocol can efficiently support both the construction of stable route and route lifetime in mobile ad-hoc wireless networks.

  • PDF

Energy Entropy based Multipath Routing Protocol using Dynamic Forwarding Range in Mobile Ad-hoc Wireless Sensor Networks (모바일 애드혹 무선 센서 네트워크에서 동적 전송범위를 사용한 에너지 엔트로피 기반 다중경로 라우팅 프로토콜)

  • Shim, Kyuhyun;Shim, Kyusung;Nam, Sangyep;An, Beongku
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.54 no.2
    • /
    • pp.68-75
    • /
    • 2017
  • In this paper, we propose an energy entropy based multipath routing protocol using dynamic forwarding range in mobile ad-hoc wireless sensor networks. The main features and contributions of the proposed routing protocol are as follows. First, can select stable routing routes by using the calculated route entropy based on energy information of sensor nodes. Second, using dynamic forwarding range based on the route stability of route entropy can reduce energy, control overhead, delay for route establishment, finally improve data transmission efficiency. The performance evaluation using OPNET shows that the proposed routing protocol can efficiently support PDR.

A Study on Network Efficiency using Limited Broadcast Mechanism for Ad hoc Network (제한된 broadcast 메커니즘을 이용한 네트워크 효율성에 관한 연구)

  • 양환석;이웅기;정종필
    • Proceedings of the Korea Multimedia Society Conference
    • /
    • 2003.05b
    • /
    • pp.45-48
    • /
    • 2003
  • Ad hoc network는 무선 노드들의 집합으로서 어떤 인프라스트럭처 도움 없이 그들 서로가 multi-hop 경로를 통해 통신한다. 네트워크를 구성하는 노드들의 움직임이 빈번히 발생하기 때문에 클러스터간 노드들의 재 가입이 계속되므로 네트워크의 안정성을 유지하기 어렵다. 그러므로 최대한 네트워크 토폴로지의 안정성을 유지하는 것이 필요하다. 본 논문에서는 ad hoc network를 구성하는 노드들을 클러스터로 형성한 후 제한된 broadcast 메커니즘을 이용하여 네트워크의 제어 메시지 flooding 수를 줄이는 효율적인 라우팅 방법을 제안한다.

  • PDF

A Path Prediction-Based Sensor Registry System for Stable Use of Sensor Information (센서 정보의 안정적인 이용을 위한 경로 예측 기반 센서 레지스트리 시스템)

  • Jeong, Dongwon;Doo, Migyeong
    • Journal of KIISE
    • /
    • v.42 no.2
    • /
    • pp.255-263
    • /
    • 2015
  • The sensor registry system has been developed for instant use and seamless interpretation of sensor data in a heterogeneous sensor network environment. However, the existing sensor registry system cannot provide information for interpretation of the sensor data in situations in which the network is unstable. This limitation causes several problems such as sensor data loss, inaccuracy of processed results, and low service quality. A method to resolve such problems in the aspect of software is presented herein. In other words, an extended sensor registry system is proposed to enable the stable use of sensor information, even under conditions of unstable network connection, by providing sensor information with a mobile device in advance through the user path prediction. The results of experiments and evaluation are also presented. The extended sensor registry system proposed in this paper enhances the stable usability of sensor information as well as improves the quality of sensor-based services.