• Title/Summary/Keyword: Locomotion system

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NUMERICAL SIMULATION OF TWO-DIMENSIONAL MICROORGANISM LOCOMOTION USING THE IMMERSED BOUNDARY METHOD (가상경계법을 적용한 2차원 미생물 이동에 관한 수치연구)

  • Maniyeri, Ranjith;Suh, Yong-Kweon;Kang, Sang-Mo
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.164-169
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    • 2009
  • Study on swimming of microorganisms like, sperm motility, cilia beating, bacterial flagellar propulsion has found immense significance in the field of biological fluiddynamics. Because of the complexity involved, it is challenging for the researchers to model such problems. Immersed boundary method has proved its efficacy in the field of biological fluiddynamics, The present work aims at performing a numerical study on the microorganism locomotion using the immersed boundary method proposed by Peskin[1]. A two-dimensional model of the microorganism is modeled as thin elastic filament described as a sine wave. The neutrally buoyant organism undergoing deformations is immersed in a viscous and incompressible fluid. The fluid quantities are described using Eulerian coordinates and the immersed body is represented by Lagrangian coordinates. The Eulerian and Lagrangian variables are connected by the Dirac delta function. The Navier-Stokes equations governing the fluid flow are solved using the fractional step method on a staggered Cartesian grid system. The developed numerical code in FORTRAN will be validated by comparing the numerical results with the available results.

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Therapeutic Approach for Stroke Patients based on Central Pattern Generator (중추유형발생기에 근거한 뇌졸중 환자의 치료적 접근)

  • Kim Joong-Hwi;Kim Chung-Sun
    • The Journal of Korean Physical Therapy
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    • v.14 no.4
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    • pp.131-146
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    • 2002
  • In the last years, it has become possible to regain some locomotor activity in patients with incomplete spinal cord injury (SCI) through intense training on a treadmill. The ideas behind this approach owe much to insights derived from animal studies. Many studies showed that cats with complete spinal cord transection(spinalized animals) can recover locomotor function. These observations were at the basis of the concept of the central pattern generator located at spinal level. The neural system responsible for the locomotor restoration in both cats and humans is thought to be located at spinal level and is referred to as the central pattern generator(CPG). The evidence for such a spinal CPG in human is emphasis on some recent developments which support the view that there is a human spinal CPG for locomotion. An important element in afferent inputs for both spinal injured cats and humans is the provision of adequate sensory input related locomotor, which can possibly activate and/or regulate the spinal locomotor circuitry This review article deals with the afferent control of the central pattern generator. Furthermore, the application of adequate afferent inputs related locomotor for stroke patients will be able to facilitate locomotion ability, which is automatic, cyclic, rhythmic. These insights can possibly contribute to a better therapeutic approach for the rehabilitation of gait in patients with stroke.

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A Study on the Development of Robust control Algorithm for Stable Robot Locomotion (안정된 로봇걸음걸이를 위한 견실한 제어알고리즘 개발에 관한 연구)

  • Hwang, Won-Jun;Yoon, Dae-Sik;Koo, Young-Mok
    • Journal of the Korean Society of Industry Convergence
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    • v.18 no.4
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    • pp.259-266
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    • 2015
  • This study presents new scheme for various walking pattern of biped robot under the limitted enviroments. We show that the neural network is significantly more attractive intelligent controller design than previous traditional forms of control systems. A multilayer backpropagation neural network identification is simulated to obtain a learning control solution of biped robot. Once the neural network has learned, the other neural network control is designed for various trajectory tracking control with same learning-base. The main advantage of our scheme is that we do not require any knowledge about the system dynamic and nonlinear characteristic, and can therefore treat the robot as a black box. It is also shown that the neural network is a powerful control theory for various trajectory tracking control of biped robot with same learning-vase. That is, we do net change the control parameter for various trajectory tracking control. Simulation and experimental result show that the neural network is practically feasible and realizable for iterative learning control of biped robot.

Bio-inspired Walking and Swimming Underwater Robot Designing Concept and Simulation by an Approximated Model for the robot (유영과 보행이 가능한 생체모방 수중 로봇의 설계개념과 근사모델을 활용한 모의실험)

  • Kim, Hee-Joong;Jun, Bong-Huan;Lee, Jihong
    • The Journal of Korea Robotics Society
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    • v.9 no.1
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    • pp.57-66
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    • 2014
  • This paper describes the design concept of a bio-inspired legged underwater and estimating its performance by implementing simulations. Especially the leg structure of an underwater organism, diving beetles, is fully adopted to our designing to employ its efficiency for swimming. To make it possible for the robot to both walk and swim, the transformable kinematic model according to applications of the leg is proposed. To aid in the robot development and estimate swimming performance of the robot in advance, an underwater simulator has been constructed and an approximated model based on the developing robot was set up in the simulation. Furthermore, previous work that we have done, the swimming locomotion produced by a swimming patten generator based on the control parameters, is briefly mentioned in the paper and adopted to the simulation for extensive studies such as path planning and control techniques. Through the results, we established the strategy of leg joints which make the robot swim in the three dimensional space to reach effective controls.

3D Reenactment System of Soccer Game (3차원 축구 재연 시스템)

  • 이재호;김진우;김희정
    • Journal of Broadcast Engineering
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    • v.8 no.1
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    • pp.54-62
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    • 2003
  • This paper presents a Soccer Game 3D Reencatment System which reenact the Important scene like getting a goal with image processing and computer graphics technologies. KBS Research Institute of Technology has developed the 3D Reenactment System of Soccer Game called ‘VPlay' to provide TV viewers with fresh images in soccer games. Vplay generates the reenactment of exciting and important soccer scenes by using computer graphics. Vplay extracts legion of players from video with color information, and then computes precise positions of players on the ground by using global motion estimation model and playground axis transformation model. The results are applied to locomotion generation module that generates the locomotion of virtual characters automatically. Using predefined motion and model library, Vplay reenacts the important scene in a quick and convenient manner Vplay was developed for live broadcasting of soccer games that demands rapid producing time and was used efficiently during past WorldCup and Asian Game.

A study on the SRF array to detect the obstacles of the mobile robot's path (이동 로보트 경로상의 장애물 검지를 위한 SRF (Sonic Range Finder) Array에 관한 연구)

  • 윤영배;이상민;홍승홍
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.87-90
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    • 1987
  • This paper gives the Sonic Range Finder(SRF) Array which detects the unknown obstacles on the mobile robot's path. This SRF Array gives mobile robot's circumstance information wider, processes and transfers them to the locomotion module to construct the modify path. In this system, 8 pairs of the 40 KHz ultrasonic sensors constitute the SRF Array, including a pair of reference sensors to correct the errors, 4051 analog multiplexer and demultiplexer swtch the sensor with time and 8031-on chip micro computer controls processes the data and communication the others.

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Control of Biped Locomotion on A Slippery Surface (미끄러운 노면에 적응하는 2족 보행 로봇의 제어)

  • 권오홍;박종현
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.41-41
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    • 2000
  • biped robots are expected to robustly traverse terrain with various unknown surfaces. The robot will occasionally encounter the unexpected events in made-for human environments. The slipping is a very real and serious problem in the unexpected events. The robot system must respond to the unexpected slipping after it has occurred and before control is lost. This paper proposes a reflex control method for biped robots to recover from slipage. Computer simulations with the 6-DOF environment model which consists of nonlinear dampers, nonlinear springs, and linear springs, show that the proposed method is effective in preventing fall-down due to slippage.

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Sliding Mode Control of 5-link Biped Robot Using Wavelet Neural Network

  • Kim, Chul-Ha;Yu, Sung-Jin;Park, Jin-Bae;Choi, Yoon-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2279-2284
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    • 2005
  • Generally, biped walking is difficult to control because it is a nonlinear system with various uncertainties. In this paper, we design a robust control system based on sliding-mode control (SMC) of 5-link biped robot using the wavelet neural network(WNN), in order to improve the efficiency of position tracking performance of biped locomotion. In our control system, the WNN is utilized to estimate uncertain and nonlinear system parameters, where the weights of WNN are trained by adaptive laws that are induced from the Lyapunov stability theorem. Finally, the effectiveness of the proposed control system is verified by computer simulations.

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Hybrid Control of 5-Link Biped Robot Using a Wavelet Neural Network (웨이블릿 신경회로망을 이용한 5링크 이족로봇의 하이브리드 제어)

  • Kim, Chul-Ha;Choi, Yoon-Ho;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2717-2719
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    • 2005
  • Generally, biped walking is difficult to control because a biped robot is a nonlinear system with various uncertainties. In this paper, we propose a hybrid control system to improve the efficiency of position tracking performance of biped locomotion. In our control system, the wavelet neural network (WNN) based on Sliding mode controller is used as a main controller which estimates a biped robot model, and the compensated controller is proposed to compensate the estimation error. A WNN is utilized to estimate uncertain and nonlinear system parameters, where the weights of WNN are trained by adaptive laws that are induced from the Lyapunov stability theorem. Finally, the effectiveness of the proposed control system is verified through computer simulations.

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