River mapping from a flying robot: state estimation, river detection, and obstacle mapping

• Published in: Autonomous robots 2012-08, Vol.33 (1-2), p.189-214
• Main Authors: Scherer, Sebastian, Rehder, Joern, Achar, Supreeth, Cover, Hugh, Chambers, Andrew, Nuske, Stephen, Singh, Sanjiv
• Format: Article
• Language: English
• Subjects: Artificial Intelligence; Computer Imaging; Computer vision; Control; Engineering; Geographic information systems; Global Positioning System; Ground level; Inertial sensing devices; Mapping; Mechatronics; Obstacle avoidance; Obstacles; Pattern Recognition and Graphics; Perception; Rivers; Robotics; Robotics and Automation; Robots; Rotary wing aircraft; Satellite navigation systems; State estimation; Three dimensional; Vision
• ISSN: 0929-5593; 1573-7527
• DOI: 10.1007/s10514-012-9293-0

Accurately mapping the course and vegetation along a river is challenging, since overhanging trees block GPS at ground level and occlude the shore line when viewed from higher altitudes. We present a multimodal perception system for the active exploration and mapping of a river from a small rotorcraft. We describe three key components that use computer vision, laser scanning, inertial sensing and intermittant GPS to estimate the motion of the rotorcraft, detect the river without a prior map, and create a 3D map of the riverine environment. Our hardware and software approach is cognizant of the need to perform multi-kilometer missions below tree level with size, weight and power constraints. We present experimental results along a 2 km loop of river using a surrogate perception payload. Overall we can build an accurate 3D obstacle map and a 2D map of the river course and width from light onboard sensing.