Navigation method for a mobile robot via sonar-based crop row mapping and fuzzy logic control

A navigation method, which employs sonar-based mapping of crop rows and fuzzy logic control-based steering, is described for a wheeled mobile robot in an agricultural environment. Crop rows are exploited for automatic navigation of a mobile robot Without the need to construct artificial landmarks. The crop row map is constructed from the sonar readings and is transferred to the fuzzy logic control system, which steers the robot along the crop row. Three experiments concerning crop row mapping, fuzzy logic control, and their combination, were conducted using the experimental robot in a simulated maizefield. The errors found in evaluating the performance of these techniques were as follows: the position and directional standard errors in the mapping tests were 12.7 mm and 2.4 degrees; those in the steering tests 16.3 mm and 2.2 degrees; and in the overall tests 33.6 mm and 3.2 degrees. (C) 1999 Silsoe Research Institute.