High level strategy to control the dynamic evolutions of bipedal postures

In this paper, we propose a high level control strategy of the dynamic evolutions of a biped robot called BIPMAN. For that, a multi-chain mechanical model of a human body is proposed with a general control architecture. Our approach is based on preliminary studies of the parameters influencing the dynamic behaviour of a mechanical model during free fall in the gravity field. This lead to a "reconfigurable" control strategy composed of three levels: the "supervisor" level, the "coordinator" level and the "legs and arms" level. The "coordinator" level and the "legs and arms" levels insure the dynamic stability of the "human" robot. According to changes of specific parameters, the "supervisor" level reactively determines the overall behaviour of the biped robot. In this article, we present behavioral rules, limiting conditions and "equilibrium classes" inferred from biomechanical studies which are involved in the design of the "supervisor" level.