A Single Actuator Driven Two-Fold Symmetric Mechanism for Versatile Dynamic Locomotion

Tumbling, rolling, and somersaults are alternate forms of locomotion used by animals and robots to navigate rough terrains. In this paper, we present a Two-Fold Symmetric (TFS) mechanism that demonstrates dynamic tumbling and leaping using a single actuator. The dynamics of the proposed mechanism are captured by a hybrid dynamic model with discrete states based on the nature of ground contact. By changing the shape parameters of a trapezoidal actuation signal, various dynamic responses and gaits are attained. Simulations and hardware experiments demonstrate tumbling and leaping/hopping. It is shown that the mechanism demonstrates gait versatility and attains speeds up to 3.0 Body Lengths per second and can jump up to a height of 60% of its total height, all using a single actuator that sets it apart from contemporary tumbling robots.