Modeling of humanoid dynamics including slipping with nonlinear floor friction

Biped locomotion created by controlling methods based on zero-moment point has been realized in real world and been well verified its efficacy for stable walking. However, the walking strategies that have been proposed so far seems to avoid such considerations as slipping of foot on the floor, even though there should exist the slipping large or small in real world. In this research, a dynamical model of humanoid robot including slipping of foot is proposed, which is derived by the Newton–Euler method. To confirm the veracity of the derived dynamical model, the model has been verified from the view point that when all friction coefficients are identical to zero, the total kinetic energy should be conserved to be unchanged, and when the coefficients are not zero, the total kinetic energy should decrease monotonously.