@article{ref1,
title="Trajectory control and its application to approach a target: Part I. Development of trajectory control algorithms for an autonomous vehicle",
journal="Transactions of the American Society of Agricultural and Biological Engineers",
year="2002",
author="Koike, M and Sutiarso, L. and Takigawa, Tomihisa and Hasegawa, Hiroshi and Kurosaki, H",
volume="45",
number="4",
pages="1191-1238",
abstract="A control method for autonomous vehicles was developed to steer the vehicle to a given target point. Since four-wheeled vehicles have constraints known as nonholonomic constraints, a nonlinear control theory was applied to generate a trajectory that would permit a vehicle to run from a starting point to its goal within these constraints by tracking it. The method was extended to turns exceeding 90° by deriving a trajectory generation method using polar coordinates. The accuracy of the control was examined by simulation and field experiments. This accurate trajectory-tracing technology can be used to fully automate agricultural operations. Since the proposed control algorithm was an open-loop control, disturbances such as wheel slippage caused navigation error. To minimize error, feedback terms were added by linearizing the vehicle's kinematic equations around a nominal trajectory generated with the open-loop algorithm.<p />",
language="",
issn="0001-2351",
doi="",
url="http://dx.doi.org/"
}