Agricultural machinery and vehicles require position data for guidance and
to control implements for optimal working positions. Position data are also
needed for such applications as precision farming. The necessary accuracy,
resolution and frequency of position data vary according to the specific a
pplication. Only one system, installed at a central vehicle (e.g. the tract
or), should provide position data for each task. The basic concept for the
proposed central system is that position data are calculated in accordance
with the application and transferred directly to the point at which they wi
ll be used. The paper describes the fundamentals of measurement and calcula
tion of position data, and gives a short introduction to the existing agric
ultural networks to transfer these data. It concentrates on a proposal for
a network service to provide and transfer position data. The solution discu
ssed is based on the agricultural BUS (DIN 9684, ISO 11783). (C) 2000 Elsev
ier Science B.V. All rights reserved.