09.12.2012 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Results and discussion<br />

where zfront is the projection <strong>of</strong> the distance between the blade <strong>of</strong> the duckfoot<br />

knife number 3 and estimated centre position <strong>of</strong> the plant to z-axis, xfront is the<br />

projection <strong>of</strong> the distance between the blade <strong>of</strong> the duckfoot knife number 3 and<br />

estimated centre position <strong>of</strong> the plant to x-axis, zrear is the projection <strong>of</strong> the<br />

distance between the blade <strong>of</strong> the duckfoot knife number 1 and estimated<br />

centre position <strong>of</strong> the plant to z-axis, xrear is the projection <strong>of</strong> the distance<br />

between the blade <strong>of</strong> the duckfoot knife number 1 and estimated centre position<br />

<strong>of</strong> the plant to x-axis (see Figure 5.25).<br />

x<br />

x front<br />

z front<br />

R front<br />

z c<br />

R rear<br />

Figure 5.25 Position <strong>of</strong> duckfoot knife trajectories approaching the<br />

crop plant with projection <strong>of</strong> their distances from the<br />

plant centre position to coordinate axis<br />

The x component can be estimated as the modified projection <strong>of</strong> the arm length<br />

to the x-axis as described in Chapter 5.2.2. The correction is necessary<br />

because the motion equations introduced in Chapter 5.2.2 were based on a<br />

simplified kinematical model <strong>of</strong> the hoeing tool. To avoid complex calculation <strong>of</strong><br />

the blade’s exact position, the modifying parameters which allow estimation <strong>of</strong><br />

the blade’s exact position were determined by experimental research. Finally,<br />

another M-file was written to summarise the distribution <strong>of</strong> distances between<br />

the blades and plants.<br />

z rear<br />

x rear<br />

5.3.7 Evaluation <strong>of</strong> the algorithm <strong>for</strong> online control <strong>of</strong> the<br />

hoeing tool by experimental testing<br />

Experimental testing <strong>of</strong> the physical prototype was done in order to verify the<br />

robustness <strong>of</strong> the <strong>system</strong> and controlling VI-s. The first test was the test <strong>of</strong> the<br />

z<br />

103

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!