Optimized non-reciprocating tripod gait for a hexapod robot with epicyclic-gear-based eccentric paddle mechanism

A novel eccentric paddle mechanism based on the epicyclic mechanism (ePaddle-EGM) has been proposed to enhance the mobility of amphibious robot for multi-environments tasks with diverse locomotion gaits, including a novel non-reciprocating legged gait. In this study, an optimized non-reciprocating planning method by planning the posture angle of the supporting paddle is focused to improve energetic efficiency of this gait. Relationship between the posture angle of the supporting paddle and actuation forces on the paddle is analyzed in the state of equilibrium. Standing on the ground vertically is found to be an optimal posture for the supporting paddle to achieve minimum quadratic sum of the actuation forces. The planning method that considers the optimal posture angle of the paddle and the stride of the gait is established and verified in simulations. Calculated specific resistance confirms that the proposed method can improve the energetic efficiency of the non-reciprocating legged gait.