Two types of quadruped robots: Bounding and walking

The design, prototype, and experiments of two types of mesoscale, four-legged mobile robots are reported in this paper. The primary characteristic of the robots is that their locomotion is realized by two piezocomposite actuators named LIPCA (Lightweight Piezoceramic Composite curve Actuator). Another significant feature is that the design of robot mechanisms is inspired by the motions of biological creatures, which leads to the two different locomotion gaits of the robots: walking and bounding. Various simulations and experiments show that the bounding robot possesses superiority over the walking one in the ability to move with a load at a fairly high velocity. On the other hand, the walking robot is found to have a clear advantage in terms of the agility of motions and ability of turning. Overall the two prototypes indicate a strong feasibility of building an autonomous legged robot actuated by smart materials.