UNCONVENTIONAL ROBOTIC ANKLE

摘要

The paper present a simultaneous force and length variation mode shape memory alloy (SMA) robotic application. The robotic ankle contains 4 SMA actuators and a spherical articulation. In order to assure a high efficient robotic architecture, the mechanical and the control structure have to assure a real-time response to the work environment changes. The load variations or the difference between the moment of full contact step and the non contact moment for a waking robot are the standard situations for a SMA robotic ankle. The paper is divided in three sections. First section makes a short introduction in the physical description and conventional applications of shape memory alloy materials. In the second part are presented mathematical model for robotic ankle. In the last section, the conventional control structures applied to the robotic ankle are explored. An experimental platform was developed and real responses of the structure to the disturbances are explored. Using Matlab/Symulink and a modified Quanser platform the experimental results are investigate, in order to highlight the advantages and disadvantages of each conventional controller.