  In this paper, a simple trajectory generation method for biped walking is
proposed. The dynamic model of the five link bipedal robot is first reduced
using several biologically inspired assumptions. A sinusoidal curve is then
imposed to the ankle of the swing leg's trajectory. The reduced model is
finally obtained and solved: it is an homogeneous second order differential
equations with constant coefficients. The algebraic solution obtained ensures a
stable rhythmic gait for the bipedal robot. It's continuous in the defined time
interval, easy to implement when the boundary conditions are well defined.
