• Title/Summary/Keyword: grasp manipulation

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A Review of Hand Function (손 기능에 관한 고찰)

  • Lee, Sun-Myung
    • Journal of Korean Physical Therapy Science
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    • v.9 no.4
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    • pp.155-168
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    • 2002
  • The purpose of study to know hand function in order to prevent disability or handicap. The ability to perform precise refined movements of hand is an important human function. Improvement in object manipulation is common goal of therapist. The ability to manipulate an object in the hand is need for many functional tasks, including writing, handling coins, small objects and ADL skills. Therapists have commonly used hand grip and pinch strengths as baseline measures to evaluate hand function. The patterns of grasps are precision grasp, power grasp, hook grasp, spherical grasp, sylindrical grasp, disc grasp, pinch, three point pinch and tip pinch. And the motion of in-manipulation are finger to palm translation, palm to finger, shift, simple rotation and complex rotation. The hand function are include to evaluate of ROM, sensation, muscle strength of hand. It used to evaluate of decision of effect and suppose of disability and acceptance of vocation. Good evaluation is need to pretreatment and baseline of treatment and help to evaluate of effect on treatment.

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Imitation Learning of Bimanual Manipulation Skills Considering Both Position and Force Trajectory (힘과 위치를 동시에 고려한 양팔 물체 조작 솜씨의 모방학습)

  • Kwon, Woo Young;Ha, Daegeun;Suh, Il Hong
    • The Journal of Korea Robotics Society
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    • v.8 no.1
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    • pp.20-28
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    • 2013
  • Large workspace and strong grasping force are required when a robot manipulates big and/or heavy objects. In that situation, bimanual manipulation is more useful than unimanual manipulation. However, the control of both hands to manipulate an object requires a more complex model compared to unimanual manipulation. Learning by human demonstration is a useful technique for a robot to learn a model. In this paper, we propose an imitation learning method of bimanual object manipulation by human demonstrations. For robust imitation of bimanual object manipulation, movement trajectories of two hands are encoded as a movement trajectory of the object and a force trajectory to grasp the object. The movement trajectory of the object is modeled by using the framework of dynamic movement primitives, which represent demonstrated movements with a set of goal-directed dynamic equations. The force trajectory to grasp an object is also modeled as a dynamic equation with an adjustable force term. These equations have an adjustable force term, where locally weighted regression and multiple linear regression methods are employed, to imitate complex non-linear movements of human demonstrations. In order to show the effectiveness our proposed method, a movement skill of pick-and-place in simulation environment is shown.

A Study on Formation of Void Space by Geometric Method and Environment-friendly Characteristics in Contemporary Housing (현대주거의 기하조작에 의한 보이드 공간의 생성과 친환경적 특성에 관한 연구)

  • Lee, Dong-Ki
    • Journal of the Korean housing association
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    • v.21 no.6
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    • pp.131-141
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    • 2010
  • This study is aimed to grasp the spatial characteristics exhibited in the modern housing architecture from the aspect of a geometrical manipulation, which transforms basic geometrical shapes and persue the formative diversity, to identify and verify the various characteristics of spatial structure in modern housing architecture. In this regard, this paper analyze and identify the influences of the void spaces that are created by geometrical manipulations on housing architecture, in terms of morphological and environmental aspects. Theoretical approaches define the concept of geometrical manipulation according to the characteristics of residence and examine the spatial features of void spaces. Additionally, case studies result in the classification of void spaces that are created by geometrical manipulation. Furthermore, to understand environment-friendly characteristics of the void space, the researcher elicited the factors that can affect environment friendly housing from previous studies, and analyzed their correlation between those factors and the void spaces that are classified.

Design of Three-Finger Hand System

  • Shim, Byoung-Kyun;Lee, Woo-Song;Park, In-Man;hwang, Won-Jun;Kim, Won-Il
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.1
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    • pp.21-26
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    • 2014
  • The focus of this paper is the designing a flexible three fingered hand system with 16 D.O.F for dynamic manipulation with an intelligent controller, and to build a useful database for dynamic manipulation based on the experimental results. The weight of the hand module is only 0.7 kg, but flexible motion and powerful grasping are possible. To achieve such a dynamic motion in a robotic hand, we have developed a flexible fingered hand with a control system incorporating image recognition system in which we deal with the problems of not only accuracy and range of motion but also the flexibility of hand. The fingers are arranged so as to grasp both circular and prismatic objects. In order to achieve the light mechanism, we reduced the number of joints and fingers as much as possible. We used three fingers, which is the minimum number to achieve a stable grasp.

Design of Three-Finger Hand System (3핑거 핸드 시스템 설계)

  • Thu, Le Xuan;Han, Sung-Hyun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.6
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    • pp.71-76
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    • 2008
  • The focus of this paper is the designing a flexible three fingered hand system with 16 D.O.F for dynamic manipulation with an intelligent controller, and to build a useful database for dynamic manipulation based on the experimental results. The weight of the hand module is only 0.7 kg, but flexible motion and powerful grasping are possible. To achieve such a dynamic motion in a robotic hand, we have developed a flexible fingered hand with a control system incorporating image recognition system in which we deal with the problems of not only accuracy and range of motion but also the flexibility of hand. The fingers are arranged so as to grasp both circular and prismatic objects. In order to achieve the light mechanism, we reduced the number of joints and fingers as much as possible. We used three fingers, which is the minimum number to achieve a stable grasp.

Regrasp Planner Using Look-up Table (참조표를 이용한 재파지 계획기)

  • Jo, Gyeong-Rae;Lee, Jong-Won;Kim, Mun-Sang;Song, Jae-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.4 s.175
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    • pp.848-857
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    • 2000
  • A pick-and-place operation in 3-dimensional environment is basic operation for human and multi-purpose manipulators. However, there may be a difficult problem for such manipulators. Especially, if the object cannot be moved with a single grasp, regrasping, which can be a time-consuming process, should be carried out. Regrasping, given initial and final pose of the target object, is a construction of sequential transition of object poses that are compatible with two poses in the point of grasp configuration. This paper presents a novel approach for solving regrasp problem. The approach consists of a preprocessing and a planning stage. Preprocessing, which is done only once for a given robot, generates a look-up table which has information of kinematically feasible task space of end-effector through all the workspace. Then, using the table planning automatically determines possible intermediate location, pose and regrasp sequence leading from the pick-up to put-down grasp. Experiments show that the presented is complete in the total workspace. The regrasp planner was combined with existing path.

A Study on Virtual Assembly Simulation Using Virtual Reality Technology (가상현실 기술을 이용한 가상 조립 시뮬레이션에 대한 연구)

  • Kim, Yong-Wan;Park, Jin-Ah
    • Journal of Korea Multimedia Society
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    • v.13 no.11
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    • pp.1715-1727
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    • 2010
  • Although a hand haptic interaction which provides direct and natural sensation is the most natural way of interacting with VR environment, the hand haptic interaction has still limitations with respect to the complexity of articulated hand and related hardware capabilities. Particularly, virtual assembly simulation which refers to the verification process of digital mockup in product development lifecycle is one of the most challenging topics in virtual reality applications. However, hand haptic interaction is considered as a big obstacle, because difficulty initial grasping and non-dextrous manipulation remain as unsolved problems. In this paper, we propose that common hand haptic interactions involves two separate stages with different aspects. We present the hand haptic interaction method enables us to stably grasp a virtual object at initial grasping and delicately manipulate an object at task operating by one's intention. Therefore, proposed method provides the robustness using grasping quality and dextrous manipulation using physically simulation. We conducted experiments to evaluate the effectiveness of our proposed method under different display environments -monoscopic and stereoscopic. From 2-way ANOVA test, we show that the proposed method satisfies two aspects of hand haptic interaction. Finally, we demonstrated an actual application of various assembly simulation for relatively complex models.

Dexterous Manipulation from Pinching to Power Grasping-Effective strategy according to object dimensions and grasping position-

  • Hasegawa, Yasuhisa;Rukuda, Toshio;Kanada, Kensaku
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.24-27
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    • 2003
  • This paper discusses practical strategies for transition from a pinching to a power grasping, where a multi-fingered hand mounted on a robotic arm envelops a cylindrical object on a table. When the manipulation system grasps a cylindrical object like a pen on a desk, a complete enveloping is not impossible in the initial configuration. The system firstly pinches the object only with two or three fingers and then grasp it with fingers and a palm after regrasping. In this pinching-grasping transition maneuver, human unconsciously selects proper strategy according to some conditions including object dimensions and initial pinching positions. In this paper we therefore develop six possible strategies for this pinching-grasping transition and then investigate their performances for some objects with various dimensions and various grasping positions, using numerical simulations. Based on their results, effective strategies are implemented by using a hand-arm system.

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Task and Motion Planning for Grasping Obstructed Object in Cluttered Environment (복잡 환경에서 가로막힌 물체 잡기를 위한 작업-모션 계획의 연계)

  • Lee, Seokjun;Kim, Incheol
    • The Journal of Korea Robotics Society
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    • v.14 no.2
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    • pp.104-113
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    • 2019
  • Object manipulation in cluttered environments remains an open hard problem. In cluttered environments, grasping objects often fails for various reasons. This paper proposes a novel task and motion planning scheme to grasp objects obstructed by other objects in cluttered environments. Task and motion planning (TAMP) aims to generate a sequence of task-level actions where its feasibility is verified in the motion space. The proposed scheme contains an open-loop consisting of three distinct phases: 1) Generation of a task-level skeleton plan with pose references, 2) Instantiation of pose references by motion-level search, and 3) Re-planning task based on the updated state description. By conducting experiments with simulated robots, we show the high efficiency of our scheme.