Image-Based Navigation for the SnowEater Robot Using a Low-Resolution USB Camera

• Published in: Robotics (Basel) 2015-06, Vol.4 (2), p.120-140
• Main Authors: Rivas, Ernesto, Komagome, Koutarou, Mitobe, Kazuhisa, Capi, Genci
• Format: Article
• Language: English
• Subjects: autonomous mobile robot; Cameras; Data buses; field robotics; image-based feedback; Markers; Navigation; Permissible error; Robots; Segments; Snow; snow-removal robot; visual localization
• ISSN: 2218-6581; 2218-6581
• DOI: 10.3390/robotics4020120

This paper reports on a navigation method for the snow-removal robot called SnowEater. The robot is designed to work autonomously within small areas (around 30 m2 or less) following line segment paths. The line segment paths are laid out so as much snow as possible can be cleared from an area. Navigation is accomplished by using an onboard low-resolution USB camera and a small marker located in the area to be cleared. Low-resolution cameras allow only limited localization and present significant errors. However, these errors can be overcome by using an efficient navigation algorithm to exploit the merits of these cameras. For stable robust autonomous snow removal using this limited information, the most reliable data are selected and the travel paths are controlled. The navigation paths are a set of radially arranged line segments emanating from a marker placed in the environment area to be cleared, in a place where it is not covered by snow. With this method, by using a low-resolution camera (640 × 480 pixels) and a small marker (100 × 100 mm), the robot covered the testing area following line segments. For a reference angle of 4.5° between line paths, the average results are: 4° for motion on hard floor and 4.8° for motion on compacted snow. The main contribution of this study is the design of a path-following control algorithm capable of absorbing the errors generated by a low-cost camera.