Walking control for a planar biped robot using 0-flat normal form

This paper deals with the use of 0-flat normal form to control a 7 d.o.f-biped robot to follow a specified trajectory. Sufficient geometrical conditions are given to transform the studied nonlinear systems into a 0-flat normal form and determine the flat outputs. On the other hand, a controller design strategy is proposed to control the walking robot. Simulations are carried out using Matlab. The results obtained are very convincing and show the usefulness of such a method in studying highly non-linear systems and designing control laws to drive them.

► We use 0-flat normal form to control a 7 d.o.f-biped robot to follow a specified trajectory.
► We give the appropriate conditions to transform the studied nonlinear system into 0-flat normal form.
► Single support phase control is considered.
► The impact model is rigid and the double support phase is instantaneous.