• Title/Summary/Keyword: force manipulability analysis

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Force Manipulability Analysis of Multi-Legged Walking Robot (다족 보행로봇의 동적 조작성 해석)

  • 조복기;이지홍
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.4
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    • pp.350-356
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    • 2004
  • This paper presents a farce manipulability analysis of multi-legged walking robots, which calculates force or acceleration workspace attainable from joint torque limits of each leg. Based on the observation that the kinematic structure of the multi-legged walking robots is basically the same as that of multiple cooperating robots, we derive the proposed method of analyzing the force manipulability of walking robot. The force acting on the object in multiple cooperating robot systems is taken as reaction force from ground to each robot foot in multi-legged walking robots, which is converted to the force of the body of walking robot by the nature of the reaction force. Note that each joint torque in multiple cooperating robot systems is transformed to the workspace of force or acceleration of the object manipulated by the robots in task space through the Jacobian matrix and grasp matrix. Assuming the torque limits are given in infinite norm-sense, the resultant dynamic manipulability is derived as a polytope. The validity of proposed method is verified by several examples, and the proposed method is believed to be useful for the optimal posture planning and gait planning of walking robots.

Dynamic Manipulability Analysis of Limb Moving in Viscous Fluid (점성유체 속에서 움직이는 로봇팔의 동적 조작도 해석)

  • 전봉환;이지홍;이판묵
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2713-2716
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    • 2003
  • This paper presents a dynamic manipulability analysis method of the limb moving in viscous fluid. The key idea of the presented method is that the boundary of joint velocity can be converted to the velocity-dependant dynamic manipulability polytope through the coriolis, centrifugal and drag terms in dynamic equation. The velocity-dependant dynamic manipulability polytope is added to the inertial and restoring force manipulability polytope to get overall manipulability polytope of the limb moving in the fluid Each of the torque and velocity bounds arc considered in the infinite norm sense in joint space, and the drag force of a limb moving in fluid viscous is modeled as a quadratic form An analysis example with proposed analysis scheme is presented to validate the method.

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Kinematic Manipulability Analysis of the Casing Oscillator (케이싱 오실레이터의 기구학적 조작성 해석)

  • Nam, Yun-Joo;Park, Myeong-Kwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.7
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    • pp.904-914
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    • 2004
  • In this paper, input-output velocity and force transmission characteristics of the Casing Oscillator which is a construction machine with 4 degrees of freedom are examined. After the Jacobian matrix is decomposed into the linear part and angular part, the velocity and force transmission characteristics for the linear and angular workspace are easily analyzed and visualized even if the Casing Oscillator has the spatial dimensional workspace with 4 DOF. Regarding the manipulability measure of the Casing Oscillator, the kinematic isotropic index and the manipulability measure which represent the isotropy and volume of the manipulability ellipsoid, respectively, are combined to coincidently consider them with respect to equivalent ranges and fluctuations. A performance of the Casing Oscillator is evaluated by the newly proposed manipulability measures.

Dynamic Modeling and Manipulability Analysis of Underwater Robotic Arms (수중로봇팔의 동역학 모델링과 동적 조작도 해석)

  • Jnn Bong-Huan;Lee Jihong;Lee Pan-Mook
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.8
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    • pp.688-695
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    • 2005
  • This paper describes dynamic manipulability analysis of robotic arms moving in viscous fluid. The manipulability is a functionality of manipulator system in a given configuration under the limits of joint ability with respect to the task required to be performed. To investigate the manipulability of underwater robotic arms, a modeling and analysis method is presented. The dynamic equation of motion of underwater manipulator is derived based on the Lagrange-Euler equation considering with the hydrodynamic forces caused by added mass, buoyancy and hydraulic drag. The hydrodynamic drag term in the equation is established as analytical form using Denavit-Hartenberg (D-H) link coordination of manipulator. Two analytical approaches based oil manipulability ellipsoid are presented to visualize the manipulability of robotic arm moving in viscous fluid. The one is scaled ellipsoid which transforms the boundary of joint torque to acceleration boundary of end-effector by normalizing the torques in joint space, while the other is shifted ellipsoid which depicts total acceleration boundary of end-effector by shifting the ellipsoid as much as gravity and velocity dependent forces in work space. An analysis example of 2-link manipulator with proposed analysis scheme is presented to validate the method.

A Study on the Task-Oriented Optimal Configuration of an ROV Mounted Manipulator Based on the Manipulability Measure (조작지수에 근거한 수중로봇팔의 작업지향적 최적자세에 관한 연구)

  • KIM Insik;JEON Bong-Hwan;LEE Pan Mook;LEE Jihong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.48-53
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    • 2004
  • In this paper, the task-oriented optimal configuration in the sense of Velocity and Force manipulability measure of manipulator mounted on ROV is considered. Manipulability is a quantitative measure of manipulator's capability obtained under the limits of joint velocities or torques. The base arrangements and optimal joint configuration of manipulator, that maximize the manipulability measure under the constraints of given task, are investigated. With the two types of base arrangements of manipulator, workspace analysis is carried out to investigate merits and demerits of each arrangement on the view of manipulability measure. To find optimal joint configuration for a given task with each arrangement, the SQP(Sequential Quadratic Programming) optimization are performed. Weighted linear combination of velocity and force manipulability measure is object function for SQP optimization. The kinematic parameters of Dual Orion manipulator which will be mounted on KORDI ROV are used for simulation.

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Manipulability Analysis of a New Parallel Rolling Mill Based upon Two Stewart Platforms (두 개의 스튜어트 플랫폼을 이용한 병렬형 신 압연기의 조작성 해석)

  • 이준호;홍금식
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.11
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    • pp.925-936
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    • 2003
  • The manipulability analysis of the parallel-type rolling mill proposed in Hong et al. [1] is re-visited. The parallel rolling mill uses two Stewart platforms in opposite direction for the generation of 6 degree-of-freedom motions of each roll. The objective of this new parallel rolling mill is to permit an integrated control of the strip thickness, strip shape, pair crossing angle, uniform wear of rolls, and tension of the strip. New forward/inverse kinematics problems, in contrast with [1], are formulated. The forward kinematics problem is defined as the problem of finding the roll-gap and the pair-crossing angle of two work rolls for given lengths of twelve legs. On the other hand, the inverse kinematics problem is defined as the problem of finding the lengths of twelve legs when the roll-gap, the pair-crossing angle, and the position and orientation of one work roll are given. The method of manipulability analysis used in this paper follows the spirit of [1]. But, because the rolling force and moment exerted from both upper and lower rolls have been included in the manipulability analysis, more accurate results than the use of a single platform can be achieved. Two. kinematic parameters, the radius of the base and the angle between two neighboring joints, are optimally designed by maximizing the global manipulability measure in the entire workspace.

Direct Control of a Passive Haptic Device Based on Passive Force Manipulability Ellipsoid Analysis

  • Changhyun Cho;Kim, Munsang;Song, Jae-Bok
    • International Journal of Control, Automation, and Systems
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    • v.2 no.2
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    • pp.238-246
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    • 2004
  • In displaying a virtual wall using a passive haptic device equipped with passive actuators such as electric brakes, unsmooth motion frequently occurs. This undesirable behavior is attributed to time delay due to slowness in the virtual environment update and force approximation due to the inability of a brake to generate torque in arbitrary directions. In this paper a new control scheme called direct control is proposed to achieve smooth display on the wall-following task with a passive haptic device. In direct control, brakes are controlled so that the normal component of a resultant force at the end-effector vanishes, based on the force analysis at the end-effector of the passive haptic device using the passive FME (Force Manipulability Ellipsoid). Various experiments have been conducted to verify the validity of the direct control scheme with a 2-link passive haptic system.

Optimal Design of a New Rolling Mill Based upon Stewart Platform Manipulator : Maximization of Kinematic Manipulability (병렬구조 신 압연기의 최적설계 : 조작성 및 제어성능의 최대화)

  • Hong, Geum-Sik;Lee, Seung-Hwan;Choe, Jin-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.9
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    • pp.764-775
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    • 2002
  • A kinematic and dynamic optimal design of a new parallel-type rolling mill based upon Stewart platform manipulator is investigated. To provide sufficient degrees-of-freedom in the rolling process and the structural stability of each stand, a parallel manipulator with six legs is considered. The objective of this new parallel-type rolling mill is to permit an integrated control of the strip thickness, strip shape, pair crossing angle, uniform wear of the rolls, and tension of the strip. By splitting the weighted Jacobian matrices Into two parts, the linear velocity, angular velocity, force, and moment transmissivities are analyzed. A manipulability measure, the ratio of the manipulability ellipsoid volume and the condition number of a split Jacobian matrix, is defined. Two kinematic parameters, the radius of the base and the angle between two neighboring Joints, are optimally designed by maximizing the global manipulability measure in the entire workspace. The maximum force needed in the hydraulic actuator is also calculated using the structure determined through the kinematic analysis and the Plucker coordinates. Simulation results are provided.

Manipulability Analysis of a Parallel Machine Tool: Application to Optimal Link Parameters Design (병렬형 공작기계의 조작성 해석: 기구부 최적설계에 적용)

  • Kim, Jeom-Goo;Hong, Keum-Shik;Park, Frank-C.;Kim, Jong-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.11
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    • pp.213-223
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    • 1999
  • In this paper, input-output transmission characteristics of the Eclipse, which is a parallel machine tool capable of 5 face rapid machining, are investigated. By splitting the weighted Jacobian matrix into two parts, the force and moment transmission characteristics together with the velocity and angular velocity transmission characteristics are analyzed. A new manipulability measure, which combines the volume of the manipulability ellipsoid and the condition number of the splitted Jcobian matrix, is proposed. Two link parameters, the ratio of upper and lower platforms' radii and the length of a supporting link of the Eclipse, are designed by applying the new manipulability measure derived. Computer simulations are provided.

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Force/Moment Transmissionability Analysis of a Parallel Manipulator (병렬형 매니퓰레이터의 힘/모우멘트 전달특성에 관한 연구)

  • Ahn, Byoung-Joon;Hong, Keum-Shik
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.4
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    • pp.109-121
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    • 1996
  • This paper presents how the input forces along the prismatic joints of a parallel manipulator are transmitted to the upper platform. In order to consider force transmission and moment transmission seperately the Jacobian matrix for parallel manipulators is splitted into two parts. Magnitudes of input forces on the six actuators at a given manipulator configuration which generate maximum/minimum output force with no moment generated on the platform are obtained through the singular value decomposition of a matrix involving the Jacobian. Similarly the directions of the input forces to obtain only the rotation of the platform have been analyzed. Using the singular values a simple equation for the volume of ellipsoid which is a good tool for manipulability measure is provided. Obtained results could be useful in determinimg design parameters like radius of plaform, angles between joints, etc. Simulations are porvided.

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