Numerical analysis of the sliding effects of a 5-DOF biped robot

When dealing with biped robots it is common to consider a set of specific assumptions in order to analyze the complete walking cycle. Among other assumptions, the non-slipping condition is a very common working hypothesis. This fact implies that the contact point between the supporting leg and the walking surface does not have a relative displacement along the walking axis. Although, in some practical situations, this movement could be neglected, this fact mainly depends on the friction characteristics between the contact points. This work is focused on the slip dynamic analysis of the supporting contact point of the stance leg of a biped robot and its walking surface. It is considered a finite-time controller in order to solve the path-tracking problem based on a Cartesian reference trajectory. It is shown how the primary effect of a sliding situation in a low friction surface is reflected directly on an actualization of the desired reference considered on the path-tracking problem.