Multi-mode Motion Control System Design and Implementation for an Air-ground Amphibious Robot

Abstract

This paper presents the design, modeling, control and experimental validation of an air-ground amphibious robot (AGAR), especially the ground-air mode-switching control in the presence of surrounding obstacles. Flight is achieved through a hexacopter unmanned aerial vehicle (UAV); six rotors produce the required thrust. Adding a wheeled mobile robot to the hexacopter makes movement on land possible. The envisioned application scenario includes field reconnaissance/surveillance in coordination with large unmanned ground vehicle (UGV) which utilizes AGAR as a multi-mode sensor. We address the controller design and the short take-off strategy for the transition between two modes of locomotion, allowing the robot to rapidly avoid obstacles in an unknown situation. A series of experiments about the obstacle detection and the mode-switching control were performed with the physical prototype; the experimental results in the field with an obstacle and a cliff confirmed the validity of our proposed method.