RHex

In biology, hexapods can walk stably in complicated terrain with tripod gait, and quadrupeds (cheetah in particular) stretch and contract their waist to run faster. These ideas are implemented on the modular robot, TWIX. TWIX is a special RHex-style robot which can switch between two modes, the hexapedal mode and the quadrupedal mode. Switching can be easily achieved because of the modular design. In the study of dynamic locomotion, TWIX is operated to approach two kinds of problems:

(1) model-based hexapod and quadruped running behaviors

(2) the effect of the waist on running behaviors

mini- RHex is a RHex-style hexapod robot which is designed for exploring two types of locomotion problems: Rough terrain negotiability and dynamic locomotion capability. In addition to ordinary tripod walking and turning behaviors, the robot can perform several different behaviors, including (1) fully autonomous step-climbing maneuver, which enables it to reliably climb a step up to 230% higher than the length of its leg; (2) model-based running behavior, which enables it to run from 1 m/s to 2 m/s without tuning or optimization efforts; (3) fully autonomous running-to-leaping maneuver.