Adaptive criteria for biped dynamic stability under external perturbations

In this paper, we propose an approach, called real time criteria and constraints adaptation, which allows one to solve the dynamic stability problem in multi-chains mechanisms field. Our approach is applied to the dynamic stability of a biped robot called BIPMAN. This relies on the analysis of position, velocity and acceleration vectors for criterion real time adaptation and on forces analysis for constraints real time adaptation. The general criterion retained allows one to optimize the force distribution as well as trunk roll and pitch angles. Ponderation coefficients are introduced into this general criterion in order to specify criteria adapted to specific classes of tasks. Many results are presented to demonstrate the criteria and constraints influences on dynamic stability and finally to validate the RTCA approach for a specific task.