• Title/Summary/Keyword: a inverse kinematics

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A Study on Inverse Kinematics Based Posture and Motion Generation System for Sports Climbing (역운동학 기반 스포츠클라이밍 자세 및 동작 생성 시스템에 관한 연구)

  • Shin, Kyucheol;Son, JongHee;Kim, Dongho
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.5
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    • pp.243-250
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    • 2016
  • Recently, public interest in virtual reality (VR) and augmented reality (AR) has increased. Therefore, computer graphics-related research has been actively conducted. This has included research on virtual space related to human posture implementation. However, such research has focused on general posture in humans. This paper presents a system with reference to the basic posture in sports climbing and the inverse kinematics method for generating the positions and behavior of virtual characteristics in a three-dimensional virtual space. The simulation based on the inverse kinematics method, produced with an inverse kinematics solver and initial pose animation from motion capture, provides realistic and natural movement. We designed a simulation system to generate correct posture and motions similar to those in sports climbing by applying the basic procedure of sports climbing. The simulation system provides help for producing content about sports climbing, such as learning programs for novice climbers and sports climbing games.

An Analysis of Inverse Kinematics and Singular Configuration for Six Axes Robot with Wrist Offset (ICEIC'04)

  • Lee YoungDae;Cho KumBae
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.263-268
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    • 2004
  • The inverse kinematics problem is to find a set of joint variable values that will place the end effector of a robot manipulator into a given pose. Pieper has shown that a sufficient condition for a manipulator to have a closed form solution is that three adjacent joint axes intersects, hence the six axes robot with spherical wrist allows closed form solution. But many industrial robots have a non-spherical wrist to provide a stronger wrist configuration so that they can handle heavy payloads. Also, the use of a non-spherical wrist can result in a cheap and simple wrist arrangement than when all three axes intersect at a common point. In these cases, closed form solutions cannot be found. Therefore numerical technique must be used to solve the inverse kinematics equations. This paper proposes a new algorithm that can be used for finding inverse kinematics solution of the six axes robot with non-spherical wrist. Computer simulations are provided to prove the usefulness of our method.

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New Continuous Variable Space Optimization Methodology for the Inverse Kinematics of Binary Manipulators Consisting of Numerous Modules (수많은 모듈로 구성된 이진 매니플레이터 역기구 설계를 위한 연속변수공간 최적화 신기법 연구)

  • Jang Gang-Won;Nam Sang Jun;Kim Yoon Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.10
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    • pp.1574-1582
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    • 2004
  • Binary manipulators have recently received much attention due to hyper-redundancy, light weight, good controllability and high reliability. The precise positioning of the manipulator end-effecter requires the use of many modules, which results in a high-dimensional workspace. When the workspace dimension is large, existing inverse kinematics methods such as the Ebert-Uphoff algorithm may require impractically large memory size in determining the binary positions of all actuators. To overcome this limitation, we propose a new inverse kinematics algorithm: the inverse kinematics problem is formulated as an optimization problem using real-valued design variables, The key procedure in this approach is to transform the integer-variable optimization problem to a real-variable optimization problem and to push the real-valued design variables as closely as possible to the permissible binary values. Since the actual optimization is performed in real-valued design variables, the design sensitivity becomes readily available, and the optimization method becomes extremely efficient. Because the proposed formulation is quite general, other design considerations such as operation power minimization can be easily considered.

Neural Learning-Based Inverse Kinematics of a Robotic Finger (뉴럴 러닝 기반 로봇 손가락의 역기구학)

  • Kim, Byoung-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.7
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    • pp.862-868
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    • 2007
  • The planar motion of the index finger in general human hands is usually implemented by the actuation of three joints. This task requires a technique to determine the joint combination for each fingertip position which is well-known as the inverse kinematics problem in robotics. Especially, it is an essential work for grasping and manipulation tasks by robotic and humanoid fingers. In this paper, an intelligent neural learning scheme for solving such inverse kinematics is presented. Specifically, a multi-layered neural network is utilized for effective inverse kinematics, where a dynamic neural learning algorithm is employed for fast learning. Also, a bio-mimetic feature of general human fingers is incorporated to the learning scheme. The usefulness of the proposed approach is verified by simulations.

A new method for solving the inverse kinematics for 6 D.O.F. manipulator (6자유도 매니퓰레이터 역기구학 해를 구하기 위한 새로운 방법)

  • 정용욱;류재춘;박종국
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.557-562
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    • 1991
  • In this paper, we present new methods for solving the inverse kinematics associated with 6 degree of freedoms manipulator by the numerical method. This method will be based on tracking stability of special nonlinear dynamical systems, and differs from the typical techniques based by the Newton-Gauss or Newton-Raphson method for solving nonlinear equations. This simulation results show that the new method is solving the inverse kinematics of PUMA 560 without the derivative of a given task space trajectories.

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Inverse Dynamic Analysis of A Flexible Robot Arm with Multiple Joints by Using the Optimal Control Method (최적 제어기법을 이용한 다관절 유연 로보트팔의 역동역학 해석)

  • Kim, C.B.;Lee, S.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.3
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    • pp.133-140
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    • 1993
  • In this paper, we prpose a method for tracking optimally a spatial trajectory of the end-effector of flexible robot arms with multiple joints. The proposed method finds joint trajectories and joint torques necessary to produce the desired end-effector motion of flexible manipulator. In inverse kinematics, optimized joint trajectories are computed from elastic equations. In inverse dynamics, joint torques are obtained from the joint euqations by using the optimized joint trajectories. The equations of motion using finite element method and virtual work principle are employed. Optimal control is applied to optimize joint trajectories which are computed in inverse kinematics. The simulation result of a flexible planar manipulator is presented.

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A Study On the Manufacturing process of Cylindrical Cam based on Relative Velocity Method and Inverse Kinematics (상대속도법과 역기구학을 이용한 원통 캠의 가공에 관한 연구)

  • 구병국;신중호;강동우;장세원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.402-405
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    • 1997
  • Based on the relative velocity method and the inverse kinematics theory, this paper presents an automated system for designing and manufacturing of an open type cylindrical cam with a rotating follower(OCRF). In the first part, this paper defines the relative velocity method for OCRF and calculates the contact point by using the coordinate transformation technique. In the second part, it generates NC Code of a CNC machine center for inverse kinematics by using the cutter location and the cutter orientation of OCRF. Finally, the automated CADICAM program developed in the paper shows an example on the desip and manufacture process of OCRF.

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Kinematics and Robust PID Trajectory Tracking Control of Parallel Motion Simulator (병렬형 모션 시뮬레이터의 기구학적 해석과 강인 궤적추종 PID 제어기의 설계)

  • Hong, Seong-Il
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.3
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    • pp.161-172
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    • 2007
  • This article suggests an inverse kinematics analysis of a two degree of freedom spatial parallel motion simulator and design methodology of the robust PID controller. The parallel motion simulator consists of a fixed base and a moving frame connected by two serial chains, with each serial chain containing one revolute joint and two passive spherical joint. First, an inverse kinematics problems are solved in order to find the joint variable necessary to bring the end effector to track the desired trajectory. Second, an inverse optimal PID controller is proposed to track trajectories in the face of uncertainty. And the $H_{\infty}$ optimality and robust stability of the closed-loop system is acquired through the PID controller. Finally numerical results show the effectiveness of the PID controller that is designed by square/linear tuning laws.

Inverse kinematics of a Reclaimer: Redundancy and a Closed- Form Solution by Exploiting Geometric Constraints (원료불출기의 역기구학: 여유자유도와 구속조건을 이용한 닫힌 형태의 해)

  • Hong, K.S.;Kim, Y.M.;Shin, K.T.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.7
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    • pp.144-153
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    • 1997
  • The inverse kinematics problem of a reclaimer which excavates and transports raw materials in a raw yard is investigated. Because of the geometric feature of the equipment in which scooping buckets are attached around the rotating disk, kinematic redundancy occurs in determining joint variable. Link coordinates are introduced following the Denavit-Hartenbery representation. For a given excavation point the forward kinematics yields 3 equations, however the number of involved joint variables in the equations is four. It is shown that the rotating disk at the end of the boom provides an extra passive degree of freedom. Two approaches are investigated in obtaining inverse kinematics solutions. The first method pre-assigns the height of excavation point which can be determined through path planning. A closed form solution is obtained for the first approach. The second method exploits the orthogonality between the normal vector at the excavation point and the z axis of the end-effector coordinate system. The geometry near the reclaiming point has been approximated as a plane, and the plane equation has been obtained by the least square method considering 8 adjacent points near the point. A closed form solution is not found for the second approach, however a linear approximate solution is provided.

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