development and testing of a portable palm tree pruning machine

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moisture contents). The device was specified to have a capacity of 4000 W with an accuracy of
±0.5%. A stop watch was used to determine the time, in seconds, consumed in cutting. Energy
was calculated by multiplying the power measurement by the time consumed in petiole cutting.
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Figure 3: The experimental setup used for testing the developed machine
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Calculation of petiole cross-section area
For each cut (each replicate) the cross section area resulting from cutting was depicted on
a paper to obtain the actual exact shape and boundaries of the cut area on a sample. A computer
program was designed to calculate the area of the depicted shapes utilizing MATHCAD software.
The program used scanned images of the depicted shapes and computed the number of pixels
contained by the shapes. Through a calibration known area in cm 2 , the program conducted a
comparison and calculated the area of the scanned irregular shapes.
RESULTS AND DISCUSSION
The results of the performance tests are shown on Fig. 4, 5, and 6. Fig. 4 shows that the
power required for cutting is inversely proportional to the petiole MC. The determination factor
(R 2 ) of this relationship was found to be 0.86 suggesting a linear relationship between the two
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