Kinematics is the analysis of motions without regarding forces or inertial effects, with the purpose of understanding joint behaviour. Kinematic data of linked joints, for example the upper extremity, i.e. the shoulder and arm joints, contains many related degrees of freedom that complicate numerical analysis. Visualisation techniques enhance the analysis process, thus improving the effectivene...

Accuracy of the final position and kinematics of movement were analysed during the imitation of meaningless gestures in patients with unilateral brain lesions who performed with the hand ipsilateral to the lesion and in control subjects. Controls imitated the gestures virtually without spatial errors. The kinematics of their movements was characterized by single-peaked and approximately bell-sh...

Two methods for determining dexterity of manipulator arms are presented. A numerical method is illustrated for determining all possible orientations of the end-effector of an open kinematic chain based upon a row-rank deficiency of the sub-Jacobian of the kinematic constraint equations. This numerical method has been adapted from a theory for determining the accessible output set for planar and...

We present an efficient algorithm for worst-case and statistical kinematic tolerance analysis of mechanisms with parametric part tolerances. The algorithm derives the kinematic variation directly from the part geometry, the part degrees of freedom, and the allowable parameter variations. It first derives a geometric representation of the kinematic variation as parametric surfaces in the mechani...

A kinematic mapping of planar displacements is used to derive generalized constraint equations having the form of ruled quadric surfaces in the image space. The forward kinematic problem for all three legged, three degree of freedom planar parallel manipulators thus reduces to determining the points of intersection of three of these constraint surfaces, one corresponding to each leg. The invers...

This paper presents a coordinate-invariant differential geometric analysis of kinematic singularities for closed kinematic chains containing both active and passive joints. Using the geometric framework developed in Park and Kim (1996) for closed chain manipulability analysis, we classify closed chain singularities into three basic types: (i) those corresponding to singular points of the joint ...

The present study is aimed at (1) testing the possibility of extracting dynamic gestural parameters from measured kinematic movement data of lingual articulation, and (2) asking the question whether these dynamic prameters may help to resolve the problem of what is articulatorily underlying the so called Ôsyllable cutÕ (ÔSilbenschnittÕ) in German. The results of the analysis of articulatory dat...

41 To characterise rugby union lineout throwing technique, three experienced 42 male rugby players performed throwing trials under varying conditions of 43 distance and trajectory. Motion analysis permitted the recovery of joint centre 44 coordinates at 120 Hz and the construction of a three-dimensional linked 45 segment model for calculation of joint angle and centre of mass time histories. 46...

This study analyzed a post office clerk's tasks, comparing two workstation models. The clerk was facing the client in one, and seated at 45 degrees to the counter in the other. We analyzed the most frequent tasks and those presenting the most critical points: 1) payment of a postal order; 2) accepting a registered letter, breaking them down into subtasks. We used an optoelectronic system for ki...

The tense and lax vowels of German were compared, based on an analysis of the duration, amplitude and velocity characteristics of lip and tongue movement. This study examined firstly whether they show different patterns of compression over changes in speech rate, and secondly whether velocity profiles would reveal evidence of different underlying control mechanisms. CVC movements were segmented...