Rule Based Simulation of Simple Object Grasping on a Graphical Manikin
VERRIEST
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Langue
anglais
Auteur
VERRIEST
Résumé / Abstract
The objective of this work is to identify rules for the simulation of grasping movements from the analysis of a data base of experimentally recorded movements. A data base of grasping movements of simple objects (cube, cylinder and sphere) ranging from 40 to 80 mm, with different grasping modes (precision and force) has been constituted through an experiment with seven (right handed) volunteers. The movements have been recorded by means of a motion capture system (VICON®) tracking surface markers located on the major joints of the seated volunteer's right hand. Each movement consisted in moving the hand towards the object, starting from a resting position located on the seat armrest and grasping the object located in front of the subject's shoulder at a distance of 2/3 of extended arm length. As a whole, 441 movements have been recorded (3 objects x 3 sizes x 7 grasping modes x 7 subjects). The surface marker 3D trajectories have been normalized in time and amplitude in order to facilitate the search for generic features in the movement history. Mobility angles of a manikin upper limb and hand model have been calculated by an inverse kinematics method. The analysis of wrist and finger angles time history allowed to identify the main features of movement organization according to object nature, size and location and according to grip type. The rules extracted from the analysis allow the construction of a grasping movement, knowing the type of object, its size and its position. From this information, a 3D trajectory of the hand to approach the object, the velocity profile, the hand orientation and the movement of the fingers are determined until the fingers hold the object.
Editeur
Chinese ergonomics society
