Spiral-STC: an on-line coverage algorithm of grid environments by a mobile robot

• Published in: IEEE International Conference on Robotics and Automation 2002 Vol. 1; pp. 954 - 960 vol.1
• Main Authors: Gabriely, Y., Rimon, E.
• Format: Conference Proceeding Journal Article
• Language: English
• Published: IEEE 2002
• Subjects: Cleaning; Flyback transformers; Machining; Mesh generation; Mobile robots; Robot sensing systems; Sensor phenomena and characterization; Shape
• ISBN: 0780372727; 9780780372726
• ISSN: 1050-4729
• DOI: 10.1109/ROBOT.2002.1013479

We describe an on-line sensor based algorithm for covering planar areas by a square-shaped tool attached to a mobile robot. Let D be the tool size. The algorithm, called Spiral-STC, incrementally subdivides the planar work-area into disjoint D-size cells, while following a spanning tree of the resulting grid. The algorithm covers general grid environments using a path whose length is at most (n + m)D, where n is the number of D-size cells and m /spl les/ n is the number of boundary cells, defined as cells that share at least one point with the grid boundary. We also report that any on-line coverage algorithm generates a covering path whose length is at least (2 - /spl epsiv/)l/sub opt/ in the worst case, where l/sub opt/ is the length of the optimal covering path. Since (n + m)D /spl les/ 2l/sub opt/, Spiral-STC is worst-case optimal. Moreover, m << n in practical environments, and the algorithm generates close-to-optimal covering paths in such environments. Simulation results demonstrate the spiral-like covering patterns typical to the algorithm.