Surface Exploration with a Robot-Trailer System for Autonomous Subsurface Scanning

Autonomous surface exploration with mobile robots entails the problem of simultaneous trajectory planning and path tracking, while also on-board robot localization and kinematics control are essential. When it comes to articulated robotic setups, planning and control is more challenging since the towed component that typically bears a tool or a sensing mechanism should closely follow a specific trajectory in order to accurately complete its task. The paper at hand presents a holistic surface exploration method with an articulated mobile robot that tows a two-wheeled trailer. A variation of Boustrophedon global path planing module has been developed considering robot's embodiment for full field coverage, integrated with a real-time Model Predictive Controller (MPC) to ensure trailer's path following. Articulated robot's state estimation is provided with stereo-based visual odometry. The system has been evaluated both in simulation and in realistic environment, proving its ability to perform dense surface exploration that in our particular case, eventually enables a Ground Penetrating Radar (GPR) mounted on the trailer to autonomously scan the entire target area.