When dealing with walking or hopping biped robots, one of the main objectives is to stand for stable periodic trajectories during regular displacements. From a state space point of view, such objective may correspond to achieve stable limit cycles (e.g. [1] [2] [3]). In such case, the major problem is to look for these potential limit cycles (i.e to prove their existence), and, if existing, to ...

This paper reports how and to what extent the mass distribution of a passive dynamic walker can be tuned to maximize walking speed and stability. An exploration of the complete parameter space of a bipedal walker is performed by numerical optimization, and optimal manifolds are found in terms of speed, the form of which can be explained by a physical analysis of step periods. Stability, quantif...

We examine two prevailing, yet surprisingly contradictory, theories of human walking. The six determinants of gait are kinematic features of gait proposed to minimize the energetic cost of locomotion by reducing the vertical displacement of the body center of mass (COM). The inverted pendulum analogy proposes that it is beneficial for the stance leg to behave like a pendulum, prescribing a more...

With free walk velocity; the individual will naturally enlist the speed that will provide maximum energy efficiency. Inspired by this idea, we exploit a passivity based control strategy to study, the preferred walking gait of a compass-like biped robot. In fact, for any ground slope, we use a dynamic optimization of the mechanical cost which is proportional to the mechanical work in the system ...

In this paper, we propose a control strategy allowing us to perform the dynamic walking gait of a virtual under-actuated robot even subjected to destabilizing external disturbances. This control strategy is based on two stages. The first one consists in using a set of pragmatic rules in order to generate a succession of passive and active phases allowing us to perform the dynamic walking of the...