DYNAMICAL ANALYSIS OF LARGE DEFLECTION COMPLIANT LEG DURING TERRESTRIAL LOCOMOTION

An amphibious robot with straight compliant flipper-legs can conquer various amphibious environments. It can rotate its flipper legs and utilize the large deflection of the legs to locomote on rough terrains, and it can oscillate the straight flipper legs to propel underwater. This paper focus on the dynamics of the compliant straight flipper legs during terrestrial locomotion. Leg's motion is modeled dynamically using large deflection theory and simulated to investigate locomotion parameters including trajectory, velocity and propulsion efficiency. In order to validate the theoretical model of the locomotion dynamics, a single-leg experimental platform is set up to explore the locomotion performance of the flipper legs with various structural and kinematic parameters. The trajectories of the rotating axle of the leg during locomotion in simulation and experiment coincide approximately. The dynamical analysis in this paper for terrestrial locomotion facilitates the implementation of amphibious robots with compliant flipper legs.