Publication

Singularity Free Parametrization of Human Limbs

Ronan Boulic, Eray Molla
2013
Conference Papers

Abstract

In this paper we propose the Middle-Axis-Rotation (MAR) parametrization of human limbs that addresses the ill-conditioned cases of analytical Inverse Kinematics (IK) algorithms. The MAR parametrization is singularity-free in the reach space of the human limbs. Unlike the swivel representation, it does not rely on the projection of an additional fixed vector. In addition, we express the joint limits of each joint of the limb in terms of the redundancy of the new decomposition. In the specific case of the upper limb, we analyse the contribution of the clavicle to produce biomechanically meaningful postures. We illustrate various real-time applications of this approach.

Official source

https://infoscience.epfl.ch/entities/publication/147314ad-3d1f-4350-9b76-4b1ee76f61df

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Ronan Boulic, Eray Molla
2013
Conference Papers

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/147314ad-3d1f-4350-9b76-4b1ee76f61df

About this result

Related concepts (29)

Upper limb

The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the arm, forearm and hand, and is primarily used for climbing, lifting and manipulating objects. In formal usage, the term "arm" only refers to the structures from the shoulder to the elbow, explicitly excluding the forearm, and thus "upper limb" and "arm" are not synonymous.

Curvature

In mathematics, curvature is any of several strongly related concepts in geometry. Intuitively, the curvature is the amount by which a curve deviates from being a straight line, or a surface deviates from being a plane. For curves, the canonical example is that of a circle, which has a curvature equal to the reciprocal of its radius. Smaller circles bend more sharply, and hence have higher curvature. The curvature at a point of a differentiable curve is the curvature of its osculating circle, that is the circle that best approximates the curve near this point.

Limb (anatomy)

A limb is a jointed, muscled appendage of a tetrapod vertebrate animal used for weight-bearing and terrestrial locomotion. The distalmost portion of a limb is known as its extremity. The limbs' bony endoskeleton, known as the appendicular skeleton, is homologous among all tetrapods, who use their limbs for walking, running and jumping, swimming, grasping and climbing. All tetrapods have four limbs that are organized into two bilaterally symmetrical pairs, with one pair at each end of the torso, which phylogenetrically correspond to the four paired fins (pectoral and pelvic fins) of their fish ancestors.

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