2006 Volume 68 Issue 1 Pages 78-86
The experiment conducted in this paper combined dead reckoning and Laser Range Finder (LRF) applications in approaching a target with forward and backward movements of an autonomous tractor. In Part 1, an LRF positioning principle using reflectors for a tractor's backward movement toward an implement was discussed. This paper deals with the switching of sensors and navigation following a course composed of multiple segmented paths. Feasible segments were designed on either polar coordinates or Cartesian coordinates. While path design by Cartesian coordinates enabled such steering as parallel parking, polar coordinate-based design enabled movements attended with turns of greater than 90°. It was confirmed by experiments that an autonomous tractor could track a multiple-segment path. Experimental results during two-segment navigation (Cartesian to Cartesian) showed that the final lateral error was 2cm and directional error was 1° at the goal position. Two-segment navigation (Polar to Cartesian) for parking a tractor in a yard showed a final lateral error of 1cm and directional error of 1°.
