• 한국컴퓨터그래픽스학회논문지
• /
• 제5권1호
• /
• pp.11-17
• /
• 1999

Example guided inverse kinematics (EGIK)는 기존의 역운동학(inverse kinematics)을 확장, 향상시키는 알고리즘이다. 기존의 역운동학은 모델자체의 redundancy에 기인하여 jerky한 동작을 만들어내는 단점이 있다. EGIK에서는 미리 측정된 동작데이타를 효과적으로 이용하여 이러한 redundancy문제를 해결한다. 이 때 end-effector 위치 차이와 관절각의 차이를 동시에 최소화하기 위해서 비선형 최적화 기술이 사용된다. 우리는 결과로서의 동작이 원래의 동작의 특성을 잘 보존하는 자연스러운 것임을 보인다. EGIK는 기존의 동작 데이타를 이용하여 다관절체의 동작을 생성해내는 효과적인 기술이다.

• 한국멀티미디어학회논문지
• /
• 제11권6호
• /
• pp.869-874
• /
• 2008

The work of creating character motion needs the higher professional technology and sense and the creating work of realistic and natural motion possess the most part of production term. In this paper we introduce the easy and convenient 3D animation authoring tool which makes the motion based on whole-body inverse kinematics and motion editing function. The proposed 3D animation authoring tool uses the forward kinematics using quaternion and whole-body inverse kinematics to determine the rotation and displacement of skeleton. Also, it provides the motion editing function using multi-level B-spline with quasi-interpolant. By using the proposed tool, we can make 3D animation easily and conveniently.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 1999년도 춘계학술대회 논문집
• /
• pp.147-151
• /
• 1999

This paper extends and enhances the existing inverse kinematics technique using the concept of motion characteristic capturing. Motion characteristic capturing is not about measuring motion by tracking body points. Instead, it starts from pre-measured motion data, extracts the motion characteristics, and applies them in animating other bodies. The resulting motion resembles the originally measured one in spite of arbitrary dimensional differences between the bodies. Motion characteristics capturing is a new principle in kinematic motion generalization to process measurements and generate realistic animation of human being or other living creatures.

• 한국정밀공학회지
• /
• 제29권1호
• /
• pp.64-71
• /
• 2012

In this paper, a parallel manipulator is comprised of two sliders and four links. Sliders execute a linear reciprocating motion depending on parallel guides and make the connected links rotate. A couple of links connected by sliders do coupling motion. The end-effector called a link tip has orientation angle. Through the kinematics analysis of this manipulator, we found displacement, velocity and acceleration using direct and inverse kinematics. We used equations that derived from this analysis and determined five constraint conditions. These conditions had much to do with rotation states of links, the relative relation of link length and coupling motion state. To verify those, we suggest a new algorithm regarding constraint conditions of a manipulator. With the result which performed the algorithm, we found out that operation range of coupled links was limited by relative relation of link length and that manipulator was not able to carry out a series of link motion, in case of being the link vertical between two parallel guides.

• 로봇학회논문지
• /
• 제10권4호
• /
• pp.230-244
• /
• 2015

Continuous-path motion control such as resolved motion rate control requires online solving of the inverse differential kinematics for a robot. However, the solution space of the inverse differential kinematics related to Jacobian J is not well-established. In this paper, the solution space of inverse differential kinematics is analyzed through categorization of mapping conditions between joint velocities and end-effector velocity of a robot. If end-effector velocity is within the column space of J, the solution or the minimum norm solution is obtained. If it is not within the column space of J, an approximate solution by least-squares is obtained. Moreover, this paper introduces an improved mapping diagram showing orthogonality and mapping clearly between subspaces, and concrete examples numerically showing the concept of several subspaces. Finally, a solver and graphics user interface (GUI) for inverse differential kinematics are developed using MATLAB, and the solution of inverse differential kinematics using the GUI is demonstrated for a vertically articulated robot.

• 한국멀티미디어학회논문지
• /
• 제17권6호
• /
• pp.741-750
• /
• 2014

This paper presents a real-time motion restoration system for people who need remedial exercise of musculoskeletal based on Inverse Kinematics. A new approach is suggested to recognize a gesture based on restored human motion which is calculated the 3D positions of intermediate joints using 3D positions of body features estimated from images. For generating the 3D candidate positions of intermediate joints which cannot be extracted from images, we apply an Inverse Kinematics theory to compute the target position of intermediate joints. And we can reduce the number of candidate positions by applying the various physical constraints of body. Finally, we can generate the more accurate final position using the Kalman filter for a motion tracking and the relationship between the previous frame information and the candidate positions. The system provide motion information which are rotation angle and height in real-time, therefore the rehabilitation exercises can be performed based on the information and figured out proper exercise for individual status.

• 한국운동역학회지
• /
• 제20권2호
• /
• pp.197-204
• /
• 2010

Scapular position and motion are essential for normal upper limb mobility; Further, the posture of patients with thoracic kyphosis is related to shoulder girdle function and disorder. The purpose of this study was to examine the effects of thoracic posture on the shoulder range of motion and on three-dimensional scapular kinematics. Thirty healthy subjects performed right-arm abduction along the frontal plane while standing in both erect and in slouched trunk posture. The scapular position and rotation, and shoulder and thoracic angles were recorded using a motion analysis system. The scapular upward rotation and internal rotation were significantly altered according to postural tatiges; however, scapular tilt was not affected. Shoulder angle was significantly decreased in the slouched posture as c rpared to tatt in the erect posture. Thus, a slouched posture(thoracic kyphosis) significantly affects the shoulder range of motion and scapular kinematics during shoulder abduction in the frontal plane.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 1998년도 추계학술대회 및 정기총회
• /
• pp.120-123
• /
• 1998

In animating an articulated entity with motion capture data, especially when the reconstruction is based on forward kinematics, there could be large discrepancies at the end effector. The small errors in joint angles tend to be amplified as the forward kinematics positioning progresses toward the end effector. In this paper, we present an algorithm that enhances the motion capture data to reduce positional errors at the end effector. The process is optimized so that the characteristics of the original joint angle data is preserved in the resulting motion. The frames at which the end-effector position needs to be accurate are designated as“keyframes”(e.g. starting and ending frames). In the algorithm, corrections by inverse kinematics are performed at sparse keyframes and they are interpolated with a cubic spline which produces a curve best approximating the measured joint angles. The experiment proves that our algorithm is a valuable tool to improve measured motion especially when end-effector trajectory contains a special goal.

• International journal of advanced smart convergence
• /
• 제10권3호
• /
• pp.149-156
• /
• 2021

Today, 3D softwares have become an essential tool in all areas of Video, including Movies, Animations, CFs, Motion Graphics and Games. One of the most commonly used fields is the 3D character video part. However, these 3D character animations and motion graphics softwares are difficult to learn and too much to learn, making it difficult to learn them all in a university education with a limited time of four years. In this paper, many Inverse kinematics tools, which are essential in the 3D character animations and motion graphics field, compare and analyze the strengths and weaknesses of each tool, focusing on Bone, Character Studio, and Character Animation Toolkit, which are most commonly used in work fields. And use Delphi techniques for 3D experts to secure objectivity. Therefore, for universities that require large amounts of teaching in a limited time, I propose an analysis of which of the above three Inverse Kinetics tools is advantageous for students to select and focus on for efficient education.

• 한국군사과학기술학회지
• /
• 제10권3호
• /
• pp.161-172
• /
• 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.