Virtual constraint based adaptive control for biped robot with speed regulation

Abstract

The Virtual Holonomic Constraint (VHC) approach, with its flexibility and stability, is drawing more attentions in generating gait for biped robots. This paper generalizes the VHC approach by adding other variables such as walking speed to the constraint functions. The robot is able to walk up or down along slopes with commanded speeds, and more importantly, allows it to walk continuously and steadily in varying surfaces. In addition, the control approach named Partial Decoupling Control is used to implement the VHC, which at the first time equips the VHC approach with the parameter adaptation laws which significantly improves the stability and performance of the systems. Full dynamics simulations with a five-bar planar robot are used to illustrate the effectiveness of the proposed approach.