Transducers speed up Auto-Hoeing.
Variohm Components have recently provided position
transducers for use on a tractor mounted hoe automatic
guidance system.
All gardeners know that the most time consuming job in the garden
is weeding. Farmers fell, the same way and they usually try to get
round the problem by using tractor mounted hoes to clean between
the rows of crops. This method can be quite effective but it is also
very time consuming since the tractor driver spends a lot of his
time looking backwards rather than just driving the tractor.
Robydome, working in conjunction with the Silsoe Research Institute,
have recently developed a auto-guidance system which keeps the
hoe in the right relationship to the crops without driver intervention
thereby allowing him to concentrate on driving, with the result that
one machine can easily achieve a work rate of 100 acres per day.
The Robydome system uses a camera mounted on the hoe frame
and a closed loop servo system. The camera takes about 25 images
per second of the area in front of the tractor, then identifies the rows
of crops and adjusts the hoe to keep the blades correctly positioned.
The actual blade position is measured by a potentiometric position
sensor type LWG supplied by Variohm Components. The LWG is an
absolute transducer which is very important in this application as the
supply to the automatic guidance system and the transducer will be
disconnected when the hoe is removed from the tractor. Because the
LWG is absolute as soon as power is restored the transducer knows
where it is and the whole system is ready for use without any further
calibration.
The LWG also offers long life and is extremely well sealed against
moisture and dirt ingress so it is ideal for agricultura' applications,
It is available in stroke lengths from 150 to 825 mm.
Variohm - Tel: +44(0) 1327 351004
October 2001
