A Hybrid Wheel-Leg Transformable Robot with Minimal Actuator Realization.

Wheel-leg transformable robots have great overall performance in various terrains by taking full advantage of both locomotion modalities. However, they tend to have much more complicated designs and actuators than single-mode robots. This paper proposes a wheel-leg transformable robot design with minimal actuator realization. To this end, we design a novel wheel-leg transformable module that uses tendon-driven mechanism for motion mode switching of each module, and a tendon network that uses a single actuator to control all tendons for mode switching of the entire robot. Hence, a N-legged robot only needs N + 1 actuators. To validate our design, we build an experiment platform, develop associated control algorithms, and conduct both simulation and field experiments over flat ground and rough terrains such as stairs and obstacles.