VIRTUAL QUADRUPED: MECHANICAL DESIGN, CONTROL, SIMULATION, AND EXPERIMENTATION

摘要

We consider a prototyped walking robot containing a platform and two double-link legs. Thus, it is a five-link mechanism. The front leg models identical motions of the quadruped's two front legs, and the back leg models identical motions of the quadruped's two back legs. The legs have passive (uncontrolled) feet that extend in the frontal plane. Because of this the robot is stable in the frontal plane. This robot can be viewed as a "virtual" quadruped. Four DC motors drive the mechanism. Its control system comprises a computer, hardware servo-systems, and power amplifiers. The locomotion of the prototype is planar curvet gait. In the double support our prototype is statically stable and overactuated. In the single support it is an unstable and underactuated system. There is no flight phase. We describe here the scheme of the mechanism, the characteristics of the drives, and the control strategy. The dynamic model of the planar walking is recalled for the double- and single-support phases and for the impact instant. The experiments give results that are close to those of the simulation.