DEALING WITH THE ILL-CONDITIONED EQUATIONS OF MOTION FOR ARTICULATED FIGURES

Realistic motion simulation for articulated figures has generated a great deal of interest in recent years. Whether the simulation is based on the kinematics or the dynamics of the figure, most formulations rely on the solution of linear systems of equations. Sometimes solution of these equations presents a great deal of numerical difficulty, resulting in unrealistic or spurious motion for the figure or in excessive computation because of small integration intervals. This article shows the cause of the difficulty to be related to the physical structure of the figure, not the mathematical formulation. It also shows how to determine the severity of ill conditioning and how to obtain physically meaningful solutions without excessive computations, even when dealing with extremely ill-conditioned configurations. © 1990 IEEE