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

Results and discussion
To demonstrate the ability of the hoeing system for adaptation to different
hoeing scenarios, a virtual mechanism of the hoeing tool consisting of 3
sections with a 3-arm hoeing subsystems (fr=front, mi=middle and re=rear) was
constructed, like it is shown in Figure 5.9.
R LA
y
x
θ δ δ
R UA
z
x
Section 3
fr3
mi3
re3
Figure 5.9 Kinematics and design of the rotary hoe
y
z
φ
Section 2
Section 1
120°
According to the plant intra-row distance, growth stage, soil surface cultivation
quality and inter-row weeding method, optimal hoeing width can be calculated
and adjusted by changing the lengths of the arms RLA+RUAcosθ and their
angular position θ in relation to the plane perpendicular to the rotation axis in
which the arm holder is placed (Figure 5.9). Thus, small duckfoot knives (cutting
tools) placed on the ends of the arms have sufficient degrees of freedom, which
allow the selection of the optimal trajectories in the intra-row and close to crop
area.
It needs to be emphasised that construction constrains RLA, δ, and number of
hoeing arms have been fixed for the set of simulations presented, but they
could be also subjects of optimisation.
For testing and simulation purposes a virtual sugar beet field was created with a
400 mm distance between the rows and a 200 mm intra-row distance between
the plants.
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