Motion capture

Technical means by which positions or orientations of corporal elements are recording during an activity. It is used, in particular, in the study of sign language, of gesture, and of visible articulators lips, chin. Three main techniques can be distinguished, (1) mechanical, which refers to accelerometers placed on the body or an exoskeleton/glove which use fiber optics or strain gauge; (2) optical or visual, with passive markers (reflecting) or active (diodes), the position of which is recorded by camera and the spatial coordinates are interpreted afterwards. The sample frequency of recent systems reaches up to 500 Hz, for a spatial precision less than a millimeter; (3) magnetic, where miniature heads can reach a sample frequency of 400 Hz. This technique allows for the recording of non-visible articulators (tongue, velum).

Contents validated by Groupe de Travail 4 (multimodality and visual-gestural modality)