SEA-Leg: A Wheel-Leg Hybrid Locomotion Platform for Uncontrolled Environments Using Series Elastic Actuators

Abstract In this paper, we present the SEA-Leg robotic mobility platform: a wheel-leg hybrid locomotion system which uses a 2 degree-of-freedom linkage driven by two series-elastic actuators to create a passive suspension system featuring the reconfigurability that makes legged systems advantageous. A method for simplifying the wheel-leg’s nonlinear dynamics to a model analogous to the traditional suspension system model is presented along with methods for its validation. A mechanical design which meets constraints outlined for SEA-Leg’s intended application as a platform for off-world exploration is presented, and a prototype was constructed. Initial testing of the SEA-Leg’s performance confirms its ability to meet the constraints laid out in this paper and implies validation of the lumped-stiffness approximation model.