• Title/Summary/Keyword: Obstacles control

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Interactive virtual laboratory for unit operations and process systems engineering education in a Web environment (웹기반 화학 단위 공정 가상 실험시스템 개발)

  • 신동일;이경용;이의수
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.313-313
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    • 2000
  • Recently the number of lectures of offered as part of distance education courses is increasing due to the necessity of continuing education in this era of rapidly changing technologies. To promote this, Web-based distance education systems have been developed and put into practical use. To step further, we propose a virtual space, distance education platform called interactive virtual laboratory. The proposed system is expected to overcome many obstacles in performing the unit operations laboratory at the current setting. The server/client system implementation was programmed with ASP and Visual Basic. The availability of simple and efficient technological supports for dissemination and remote use of virtual lab systems supports more experimental practices regardless of the number of participating students and their locations. Variety of instruments, process equipments and lab procedures are being added to make it a complete package of virtual lab fur undergraduate unit operations course.

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Moving Window Technique for Obstacle Detection Using Neural Networks (신경망을 사용한 장애물 검출을 위한 Moving Window 기법)

  • 주재율;회승욱;이장명
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.164-164
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    • 2000
  • This paper proposes a moving window technique that extracts lanes and vehicles using the images captured by a CCD camera equipped inside an automobile in real time. For the purpose, first of all the optimal size of moving window is determined based upon speed of the vehicle, road curvature, and camera parameters. Within the moving windows that are dynamically changing, lanes and vehicles are extracted, and the vehicles within the driving lanes are classified as obstacles. Assuming highway driving, there are two sorts of image-objects within the driving lanes: one is ground mark to show the limit speed or some information for driving, and the other is the vehicle as an obstacle. Using characteristics of three-dimension objects, a neural network can be trained to distinguish the vehicle from ground mark. When it is recognized as an obstacle, the distance from the camera to the front vehicle can be calculated with the aids of database that keeps the models of automobiles on the highway. The correctness of this measurement is verified through the experiments comparing with the radar and laser sensor data.

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The Comparison of Plantar Foot Pressure Distribution in Adult and Elderly according Obstacle Heights (장애물 높이에 따른 성인과 노인의 족저압 분포 비교)

  • Chang, Jong-Sung;Lee, Myoung-Hee
    • The Journal of Korean Physical Therapy
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    • v.26 no.4
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    • pp.257-261
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    • 2014
  • Purpose: The purpose of this study was to compare plantar foot pressure distribution in adults and elderly according to obstacle height. Methods: Nine healthy adults and nine older adults were recruited and the subjects provided written informed consent consent prior to participation. Both groups walked and crossed obstacles with heights of 0%, 10%, 20%, and 30% of their height. Foot pressure was measured by peak pressure using the Pedar System (Novel Gmbh, Germany) during obstacle walking with barefeet in shoes. Three trails were calculated on eight areas and then averaged for data analysis. Results: A significant difference in great toe, little toes, and lateral metatarsal area was observed between adults and elderly groups, but other areas did not show significant differences. Foot pressure was increased in groups according to obstacle height. Conclusion: These findings showed that change in foot pressure distribution is more lateral in elderly in order to maintain postural control during obstacle crossing.

Nano Catalysts for Proton Exchange Membrane Fuel Cells

  • Kim, Su-Gil;Hwang, Seung-Jun;Im, Ji-Eun;Yu, Seong-Jong;Lee, Seung-Cheol;Im, Tae-Hun
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.71.1-71.1
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    • 2012
  • Proton Exchange Membrane Fuel Cells (PEMFCs) have been of great interest particularly in the automobile industries because of their high energy density and low pollutant emission. However, some of the issues such as, the necessarily high contents of Pt catalysts and their slow kinetics of cathode oxygen reduction reaction remain as obstacles in the commercialization of the PEMFC. In this presentation, after brief explanation on basic principles of PEMFC and its application to FC vehicles, recent researches to improve the activity and durability of Pt-based nano catalysts toward oxygen reduction will be introduced. It covers size and shape control of Pt nano particle, binary and ternary Pt-M alloys, novel core-shell nano structures of Pt, and a little bit about non-Pt catalysts. Strategies and methodologies for design and synthesis of novel catalysts will also be included.

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Sequential Catalytic Combustion System (순차식 촉매연소 시스템)

  • 유상필;정남조;이승재;류인수;강성규;송광섭
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2004.05a
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    • pp.197-200
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    • 2004
  • Compared to conventional flame combustion, catalytic combustion had the advantage of oxidation of V.O.C. gas which was high voluminous, low caloric mixture flow. However, the temperature of mixture gas should be over the one of catalytic reaction start and the control of reaction on the catalytic surface tends to be vulnerable. To overcome these obstacles, composition of both catalytic combustor and heat exchanger was devised and named the sequential catalytic combustion system. In this system, only trigger unit needed preheating process for transient starting time. Once trigger unit was ignited, the next unit w3s supplied heat to ignite from that and same process was performed to the last one sequentially. When it come to steady state, whole mixture gas was oxidated at each unit simultaneously and preheating for trigger unit was not needed any more. System of 100 kcalh/hr capacity was devised and operated successfully.

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Development of Vision based Autonomous Obstacle Avoidance System for a Humanoid Robot (휴머노이드 로봇을 위한 비전기반 장애물 회피 시스템 개발)

  • Kang, Tae-Koo;Kim, Dong-Won;Park, Gwi-Tae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.161-166
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    • 2011
  • This paper addresses the vision based autonomous walking control system. To handle the obstacles which exist beyond the field of view(FOV), we used the 3d panoramic depth image. Moreover, to decide the avoidance direction and walking motion of a humanoid robot for the obstacle avoidance by itself, we proposed the vision based path planning using 3d panoramic depth image. In the vision based path planning, the path and walking motion are decided under environment condition such as the size of obstacle and available avoidance space. The vision based path planning is applied to a humanoid robot, URIA. The results from these evaluations show that the proposed method can be effectively applied to decide the avoidance direction and the walking motion of a practical humanoid robot.

An Autonomous Mobile Robot Control Method based on Fuzzy-Artificial Immune Networks and RBFN (퍼지-인공면역망과 RBFN에 의한 자율이동로봇 제어)

  • 오홍민;박진현;최영규
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.12
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    • pp.679-688
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    • 2003
  • In order to navigate the mobile robots safely in unknown environments, many researches have been studied to devise navigational algorithms for the mobile robots. In this paper, we propose a navigational algorithm that consists of an obstacle-avoidance behavior module, a goal-approach behavior module and a radial basis function network(RBFN) supervisor. In the obstacle-avoidance behavior module and goal-approach behavior module, the fuzzy-artificial immune networks are used to select a proper steering angle which makes the autonomous mobile robot(AMR) avoid obstacles and approach the given goal. The RBFN supervisor is employed to combine the obstacle-avoidance behavior and goal-approach behavior for reliable and smooth motion. The outputs of the RBFN are proper combinational weights for the behavior modules and velocity to steer the AMR appropriately. Some simulations and experiments have been conducted to confirm the validity of the proposed navigational algorithm.

Alternative impression technique for multiple abutments in difficult case to control

  • Jung, Bock-Young;Lee, Keun-Woo
    • The Journal of Advanced Prosthodontics
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    • v.2 no.1
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    • pp.1-3
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    • 2010
  • BACKGROUND. Even though excellent impression materials are now available for making accurate replication for hard and soft tissue, the numerous dentists have faced lots of obstacles in making simultaneous impressions of multiple abutments. CASE DESCRIPTION. This article describes a modified method of tray fabrication using auto-polymerizing acrylic resin and impression technique for multiple prepared teeth in cases with limitations and difficulties in taking dental impressions. CLINICAL IMPLICATION. This segmental tray technique has several advantages, including higher impression quality, fewer impressions, and being more comfortable for the patient and less stressful for the clinician.

A Study on the Trajectory Control of a Autonomous Mobile Robot (자율이동로봇을 위한 경로제어에 관한 연구)

  • Cho, Sung-Bae;Park, Kyung-Hun;Lee, Yang-Woo
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2417-2419
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    • 2001
  • A path planning is one of the main subjects in a mobile robot. It is divided into two parts. One is a global path planning and another is a local path planning. This paper, using the formal two methods, presents that the mobile robot moves to multi-targets with avoiding unknown obstacles. For the shortest time and the lowest cost, the mobile robot has to find a optimal path between targets. To find a optimal global path, we used GA(Genetic Algorithm) that has advantage of optimization. After finding the global path, the mobile robot has to move toward targets without a collision. FLC(Fuzzy Logic Controller) is used for local path planning. FLC decides where and how faster the mobile robot moves. The validity of the study that searches the shortest global path using GA in multi targets and moves to targets without a collision using FLC, is verified by simulations.

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Design of Rescue Robot in Hazardous and Disastrous Environment

  • Kwak, Sung-Hun;Choi, Gi-Sang;Choi, Gi-Heung
    • International Journal of Safety
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    • v.6 no.1
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    • pp.11-15
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    • 2007
  • In many cases, rescue robots work under harsh conditions such as the presence of various obstacles, high temperature, and limited visibility, etc. These robots are required to have tough mechanical structure, good sensing and control capability, and reliable communication capability for receiving operator's command and sending information on the state of the robot and environment. In this study, a rescue robot that can investigate hazardous or disastrous sites with these capabilities is designed and implemented. The performance of the proposed rescue robot is tested under simulated disastrous environment.