Toward a Track-Fin Hybrid Driven Bionic Amphibious Robot: Design, Development, and Experiments

Abstract

Amphibious robots offer promising applications in field scenarios such as search and rescue, exploration and reconnaissance, and environment monitoring. However, achieving high locomotion performance in terrestrial, aquatic, and soft muddy transition areas remains challenging. This study presents a novel amphibious robot based on the hybrid drive of tracks and bionic fins. The robot is driven by a pair of tracks on land and by a pair of undulating fins underwater, without the need for switching operating modes due to the simultaneous drive of the two components. The structure design is introduced and the united operating strategies are derived for propulsion in multiple environments propulsion. A land–water united controller for the heading angle and track/fin frequency is designed based on a mathematical model. In field experiments, the robot achieved the maximum linear velocities of 2 m/s on land and 0.51 m/s underwater, with maximum yaw rates of 225 ${}^{\circ }/s$ and 100 ${}^{\circ }/s$, respectively. The robot could transition seamlessly between land and water in less than 2 s. The closed-loop control experiments demonstrated that the robot could quickly follow the desired angle with minimal error in both media using the same controller and parameters. The proposed simultaneous drive method enhances the multi-terrain motion capacity and cross-medium performance while reducing control complexity of amphibious robot, providing a new perspective for the development of self-adaptive and high-performance amphibious robots for practical application.