Design of a Variable Wheel-Propeller Integrated Mechanism for Amphibious Robots

In order to address the high complexity and low efficiency of amphibious propulsion systems, this paper proposes a novel variable wheel-propeller integrated mech- anism for amphibious robots. By adjusting the blade pitch angle, it enables multiple motion modes, including rapid and stable movement on flat ground, obstacle crossing, and omnidi- rectional movement on water surface. This study establishes a kinematic model for the propeller blades and conducts multi-objective optimization of the structural parameters by considering both the land obstacle-crossing performance and underwater propulsion performance. Based on the optimized structural parameters, a virtual simulation prototype is con- structed. Simulation results indicate that when water surface movement, with a driving torque of 3N.m, robot achieves a maximum linear velocity of 1.25m/s and a maximum angular self-rotation velocity of 3.5rad/s. Moreover, varying the blade pitch angle can alter the thrust direction, enabling omnidirec- tional mobility on water surface. During land movement, with a rotation speed of 60rpm, the highest obstacle-crossing height is 184mm. This wheel-propeller integrated mechanism exhibits robust comprehensive motion performance and environmental adaptability, with convenient motion modes switching.