Kinematical Behavior Analysis and Walking Pattern Generation of a Five Degrees of Freedom Pneumatic Robotic Leg

Abstract

The work presented provides an accurate analysis of the kinematical behavior and a brief description of the mechanical structure of an anthropometric robotic leg. The prototype realized has five degrees of freedom and three articulations actuated by five pneumatic pistons. Two pistons actuate the hip articulation, and other two move the ankle articulation, while the knee articulation has only one degree of freedom. To control the joint trajectories a two level control algorithm is implemented, in which each piston position is controlled by one piston control board, while the PC generate the joint trajectories once sampled the piston position and operated a proper kinematical inversion. Moreover, in order to ensure a more easy trajectory generation, a three-dimensional control strategy has been implemented directly into the operative space. The first walking patter trajectories have been also generated and some experimental results are reported.