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

Horizontal position (x) [mm]
Vertical position (y) [mm]
400
200
0
-200
-400
50
0
-50
mi1
re1
+
fr2
mi2
re2
Results and discussion
400 500 600 700 800 900 1000 1100
Travelled distance (z) [mm]
re1 fr2 mi2 re2
fr3 mi3 re3 fr1
400 500 600 700 800 900 1000 1100
Travelled distance (z) [mm]
+
mi3
+ + +
Figure 5.11 Hoeing trajectories of the hoeing tool with nine arms in a
field with 300 mm intra-row distance between plants
(arm length 440 mm, angular position of all arms
adjusted to 0°, � - position of the plant)
The trajectories of the duckfoot knives under the soil surface for equal length of
the arms can be optimised by adjustment of the angular position of the arms θ.
The main advantage of this kind of fine-tuning is that a small angular change
provides the possibility of controlling the distance between consecutive cuts of
each section. Also, the adjustment of the angular position of the arms θ affects
the penetration order of the front, middle and rear duckfoot knives of each
section, forwards or backwards, in relation to the z-axis. An example of the
forward-backward rearrangement of the trajectories by changing the angular
position of the front and rear duckfoot knives in each section on the rotary hoe
with nine arms is illustrated in Figures 5.12 and 5.13. The segments of the
trajectories under the soil surface are highlighted on both graphs. The expected
crop positions are x=200 mm, 400 mm, 600 mm; y=0 and they are marked with
“+” on the graphics.
fr3
re3
+
fr1
79