@article{ref1,
title="Trajectory control and its application to approach a target: Part II. Target approach experiments",
journal="Transactions of the American Society of Agricultural and Biological Engineers",
year="2002",
author="Hasegawa, Hiroshi and Yukumoto, O and Koike, M and Takigawa, Tomihisa and Kurosaki, H and Sutiarso, L.",
volume="45",
number="4",
pages="1199-1205",
abstract="A positioning method using a simple laser sensor was developed and employed for navigation to a target. The laser sensor scans existing reflectors and measures their directions and positions using a triangulation method. After calibration, the accuracy of distance measurement was around 10 cm. A control system that steers an autonomous vehicle following a human-operated tractor was also developed. Experiments regarding the application of the laser sensor confirmed that an experimental autonomous tractor could follow a leading human-operated tractor without collision. However, the autonomous tractor tended to take shortcuts due to feedback. Automatic fertilizer refilling experiments were conducted using an autonomous vehicle equipped with a broadcast fertilizer distributor. The laser positioning method was used to locate the fertilizer supplier. Results of the field experiment showed that the trajectory control algorithm proposed in Part I could guide the vehicle with satisfactory accuracy for refilling. The main factor contributing to navigation error was the limit of the steering angle of the front wheels.<p />",
language="",
issn="0001-2351",
doi="",
url="http://dx.doi.org/"
}