Recognising plants with ultrasonic sensing for mobile robot navigation

Mobile robots navigate through many environments that contain plants. A sen sor that can recognise plants would be useful for navigation in these envir onments. Two problems make plant sensing difficult: plant similarity and pl ant asymmetry with rotation. a continuously transmitted frequency modulated ultrasonic sensor produces a return signal that contains information about the geometric structure: of plants. Correlation of echoes from many orient ations show that plants can be recognised with sufficient accuracy for navi gation. (C) 2001 Elsevier Science B.V. All rights reserved.