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

Results and discussion
Based on indicated requirements the optimal distance can be identified. For the
average intra-row distance between plants of 200 mm optimal distance can be
calculate as:
⎛ 2 1 ⎞ 13
Dsens −hoe
= ⎜ + 1+
⎟d
= d
⎝ 3 2 ⎠ 6
for d= 200 mm
(5.16)
D − = 433,33 mm ≈ 435 mm
(5.17)
sens hoe
This value is optimised for the hoeing tool with three arms, three cuts between
two successive plants, average intra-row distance about 200 mm and initial
position of the system as shown in Figure 5.19.
Using the same approach presented in this chapter, there is a possibility to
calculate the optimal distance between the detection unit and the plane in which
the hoeing tool is placed, for other hoeing strategies with different number of
arms, increased or decreased number of cuts between successive plants and
alternative intra-row distances between plants.
As mentioned, the software solution requires centre positions of two following
plants for calculation of the forward speed. Using such a method of speed
acquisition, the necessity for implementation of an additional hardware system
for speed measurement was avoided. Of course, application of an additional
hardware would simplify the software, because calculation of the forward speed
would not be necessary, and it would allow shortening of the distance between
the detection unit and the plan in which the hoeing tool is placed for one
average intra-row distance.
To avoid additional investments into speed measuring hardware, whose costs
grow with the required accuracy, especially in low speed ranges, the alternative
of speed measurement with software was chosen.
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