ZMP based pattern generation for biped walking using Optimal Preview Integral Sliding Mode Control

This paper describes a method for biped walking pattern generation by using discrete Optimal Preview Integral Sliding Mode Control (OPISMC) of the zero-moment point (ZMP). First, the 3D-linear inverted pendulum mode (3D-LIPM) model used to model biped dynamics is presented. The optimal preview controller that uses future ZMP reference information is designed to satisfy a linear quadratic performance index. The integral sliding mode control is then employed to robustify the optimal preview controller. This control method has merits of both the optimal preview control and the sliding mode. The effectiveness of the approach is tested via simulations. Results indicate that the proposed pattern generation technique is successful.