Development of a novel mechatronic system for mechanical weed ...

Results and discussion
between the arm (duckfoot holder) and foliage system because of asymmetric
shape of the duckfoot knives (see Figure 5.25). The size of the uncultivated
area, which corresponds to the protected area around the plant, can be
described with a circle which diameter is equal to the distance between centre
position of the plant and nearest position of the blade which was detected
during the measurement. In this experiment the nearest detected position of the
blade was 27 mm distanced from the plant centre position, hence an area
around the plant with diameter at least big as dp = 54 mm was left uncultivated.
As the size of the test plants was between 35 and 50 mm, no plant was
endangered by the weeding process. The graph b) shows the mean distances
between duckfoot knife number 3 (marked with �) and duckfoot knife number 1
(marked with �) for every longitudinal position in which they appear, in relation
to the plant centre position (marked with �). For every longitudinal position
beside the mean values, the ranges between the minimum and maximum are
pointed out.
x [mm]
106
100
50
0
-50
-100
+
dp=54 mm
-100 -50 0
z relative [mm]
50 100
Distance from the plant centre position [mm]
140
120
100
80
60
40
20
0
+
-80 -60 -40 -20 0 20 40 60 80
z relative [mm]
Figure 5.27 Estimation of the hoeing quality attained during the
experiment with constant speed a) distribution of the cuts
under the soil surface transformed to a relative distance
from the plant centre position (�) for duckfoot number 3
(�) and duckfoot number 1 (�); b) mean distances of
duckfoot number 3 (�) and duckfoot number 1 (�) in
relation to the plant centre position (�)