• Title/Summary/Keyword: gravity center

Search Result 886, Processing Time 0.028 seconds

A Design of Adaptive Steering Controller of AGV using Immune Algorithm

  • Lee, Chang-Hoon;Lee, Jin-Woo;Lee, Kwon-Soon;Lee, Young-Jin
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2002.10a
    • /
    • pp.120.3-120
    • /
    • 2002
  • 1. Introduction $\textbullet$ Immune system is an evolutionary biological system to protect innumerable foreign materials such as virus, germ cell, and etc. Immune algorithm is the modeling of this system's response that has adaptation and reliableness when disturbance occur. $\textbullet$ In this paper, Immune algorithm is applied to the Steering Controller of AGV in container yard. $\textbullet$ And then the computer simulation result from the viewpoint of yaw rate and lateral displacement is analyzed and compared with result of conventional PID controller. 2. Dynamic Modeling of AGV $\textbullet$ Dynamic modeling has high degree of freedom. But, basic assumptions of this model are that the center of gravity(CG)...

  • PDF

Precision enhancement for a CCD/LSB type shape measuring system (CCD/LSB 방식의 형상측정시스템의 정밀도 향상 방법)

  • 유주상;정규원
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2001.04a
    • /
    • pp.137-142
    • /
    • 2001
  • Since recent production system becomes that of the small quantity, large volume with high quality production, accurate and high speed inspection system is required. In such situation, noncontact 3D measurement system which utilized CCD cameras is useful technique in terms of system cost, speed of data acquisition, measuring accuracy and application. However, it has low accuracy compared with contact 3D measurement system because of the camera distortion, non uniformity of laser distribution and so on. For those reasons, in this paper precision enhancement method is studied considering radial camera distortion, and laser distribution. A distortion correction method is applied even to the standard lens. The laser slit beam trajectory is determined by 3 method: based of the Gaussian function signal approximation, the median method, the center of gravity method and the peak point of the Gaussian function method.

  • PDF

A study on Dynamic Gait Quadruped Walking Robot (사각 보행 로봇의 동적 걸음새에 관한 연구)

  • 김진섭;오준호;조진철
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.04a
    • /
    • pp.78-81
    • /
    • 1997
  • In this study, we prepose the dynamic gait in consideration of emerge efficiency. The proposed dynamic gait is applied to the quadruped walking robot and experiments are performed for real robot. We proposed the dynamic gait is diagonal gait which is modified the trot gait in consideration of energy efficiency. The proposed gait is composed of two steps. In one step, the robot walks in the trot gait. In the other step, the robot walks with making the center of gravity lie on the two legs supporting line. Realization of the diagonal intermittent trot gait is performed by open loop contal and motion planning of the proposed gait. The validity of the purposed gait is confirmed by our experiment.

  • PDF

A Study of Muscular Imbalance (근육 불균형에 관한 연구)

  • Bae, Sung-Soo;Kim, Byung-Jo
    • The Journal of Korean Physical Therapy
    • /
    • v.13 no.3
    • /
    • pp.821-828
    • /
    • 2001
  • Muscle imbalance describes the situation in which some muscles become inhibited and weak, which others become tight, losing their extensibility. Muscle imbalance develops mainly between tightness and inhibition. Although muscle imbalance involves the whole body, the imbalance is more evident or starts to develop gradually and predictably in the pelvic region, where we speak about the pelvic or distal crossed syndrome, and the shoulder girdle. neck region, associated with a proximal or shoulder girdle crossed syndrome. Evaluation of muscle imbalance in a patient can be from location of the line of gravity in relation to the trunk.

  • PDF

A Study of Muscle Imbalance of Head, Cervical and Shoulder Region (두부, 경부, 견부의 근육불균형에 관한 연구)

  • Bae, Sung-Soo;Kim, Byung-Jo;Lee, Keun-Heui
    • The Journal of Korean Physical Therapy
    • /
    • v.13 no.3
    • /
    • pp.769-776
    • /
    • 2001
  • This study were to review of muscle imbalance of head, cervical and shoulder region. Head, cervical and shoulder region is a complicated mechanical unit. interconnected by numerous soft tissue links. These links, or articulation are functionaly and reflexly interdependent on one another. The line of gravity falls anterior to the transverse axis of rotation for flexion and extension of the head and creates a flexion moment. which tends to tut the head forward, is counteracted by tension in the tectorial membrane, and ligamentum nuchae, and by activity of the neck extensors. Therefore, the flexion moment equilibrate with the extension moment. Changing of the equilibrium will make mid cervical straight. It will make forward head posture(FHP) also. FHP makes imbalance of suboccipital muscles, suprahyoid muscles and infrahyoid muscles. It has some relationship with temporomandibular joint, spine and equilibrium of pelvis.

  • PDF

Subhamonic Resonances of order 1/2 of Continuous Rotor with Nonlinearity and Internal Resonances (비선형 연속축의 1/2차 분수조화진동 및 내부공진)

  • 남궁재관;이성우
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.10 no.1
    • /
    • pp.43-50
    • /
    • 2001
  • Subharmonic resonances of order 1/2 of a continuous rotating shaft with distributed mass are discussed. The restoring force of the shaft exhibits geometric stiffening nonlinearity due to the extension of the shaft center line. It is assumed that a distributed lateral force, such as the gravity, acts on the rotor. The possibility of the occurrence of subharmonic resonances, the shapes of resonance curves, and internal resonance phenomena are investigate.

  • PDF

Eigenvalue Sensitivity of Rigid Body Mode for Vehic1e Powertrain System (차량 파워트레인계의 강체고유진동수 민감도)

  • 원광민;강구태
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.05a
    • /
    • pp.609-615
    • /
    • 2001
  • In this paper, the eigenvalue sensitivity of vehicle powertrain was investigated by analytic method. The powertrain system was considered as a rigid body with multiple engine mounts, and the engine mounts were supposed as three linear springs in three orthogonal directions. The design parameters for the sensitivity analysis were engine mount properties (positions, stiffness, and orientations) and powertrain properties (mass, second moment of inertia, and center of gravity). Firstly, an effective form of eigenvalue problem for the powertrain system was introduced. Then, the analytic sensitivity of eigenvalue was derived using the equation. Lastly, the derived sensitivity equation was applied to a real powertrain system to provide its correctness and applicability.

  • PDF

Development of evaluation program for vibration characteristics of onboard machinery with resilient mountings (선내 탑재 장비용 마운팅 시스템의 진동특성 평가 프로그램 개발)

  • Kim, Kuk-Su;Choi, Su-Hyun;Baek, Il-Cuk;Cho, Yeon;Kim, Byoung-Gon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.05a
    • /
    • pp.155-160
    • /
    • 2001
  • This study is performed to evaluate and design the vibration characteristics of the onboard machinery with resilient mountings. To reduce the vibration level of onboard machinery with resilient mountings, it is important to evaluate and, if necessary, modify the vibration characteristics of the resilient mountings. In this study, we have developed a program to calculate natural frequencies of the machinery with resilient mountings, forced vibration levels due to internal excitation force of the machinery itself and external excitation forces. of the main engine and the propeller. and the force and motion transmissibility of the resilient mountings. The developed program is also able to be applied to optimal design of the resilient mountings for obtaining a target natural frequency and for achieving a minimum forced vibration level at the center of gravity of the machinery.

  • PDF

Development of the propellant grain design program (추진제 그레인 설계 프로그램 개발)

  • Lee, Do-Hyung;Yang, June-Seo;Oh, Seok-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2007.11a
    • /
    • pp.207-210
    • /
    • 2007
  • This paper describes the development of the grain design automation program using commercial CAD(computer-aided-design) software. This program allows to readily obtain output of burning area, volume, moments of inertial, motion of the center of gravity, and other geometric data as a function of regressed distance. These are utilized in performance analysis.

  • PDF

The Status of Accident and Prevention Measures for Ladles (래들에 의한 재해발생 실태와 예방대책)

  • Choi, Seung Ju;Shin, Woon Chul
    • Journal of the Korea Safety Management & Science
    • /
    • v.16 no.3
    • /
    • pp.201-207
    • /
    • 2014
  • This study is aimed to improve safety of ladle in the metal products manufacturing industry. Burns may occur from spills, spatters or eruptions of hot metal from ladles during pouring or transporting. According to the statistics of occupational accidents about the ladle, many victims were exposed to or contacted with extreme temperatures. The many fatal injuries occurred as a result of unexpected discharging of molten metal due to tipping over ladles. To prevent ladles from turning over, the trunnion axis shall be located below the center of gravity of the ladle at all operating condition. For this purpose, the equation is proposed to calculate the minimum location of a trunnion axis for definite static stability when tilting.