Simulation and modelling of virtual operators for workspace design

This paper deals with modelling of human movement in order to provide an analysis and simulation tool which could be used for workspace design. We are interested in systematic generation of human motion and postures that correspond to working tasks defined by grasps or, more generally, by locations of particular frames linked to hands, head or another body of interest. These tasks are reaching - point to point - tasks or tasks with imposed cartesian path. So the problem is : how to control global posture when frames attached to some bodies are imposed ? In the general case, the constraints imposed by the task are equality constraints imposed by kinematics on one side, and obstacles or articular bounds defining inequality constraints on another side. When there is less equality constraints than independent control variables, then the problem is redundant and many solutions realize the constraints. Since the goal is to provide a realistic simulation in order to predict real human motion, redundancy has to be used to obtain realistic movements, to avoid collisions with 3D environment and to take into account articular limitations.