​​Selection of a Cutting Mechanism and Optimization of Parameters for Coconut Harvesting Drone

Background: Coconut (Cocos nucifera L.) palm is an important cash crop in India and third-largest producer of coconut in the world. In general, the skilled workers climb to harvest the coconuts from the tree without any safety device. The coconut trees are very tall and injuries associated with coconut tree climbing, particularly falling from coconut trees is common in coconut plantations. In order to rectify the problem, an appropriate cutting system needs to be developed. Hence the characterizing physical and mechanical properties viz., peduncle thickness, width, shape, size, moisture content, density and also the cutting blade characteristics, were studied. Methods: The observed characteristics were used for the effective design of the cutting module. The cutting blades were selected for the investigation viz, circular saw blade and saw tooth blade. The parameters selected for the investigation are cutting speed (S) at three levels (15.70, 20.94 and 26.17 ms-1), the inclination angle of the blade (q) five levels (30, 45, 60, 75 and 90°), type of the blades (B) (regular tooth and ripped tooth pitch) and thickness of peduncle (T) three levels (30, 40 and 50 mm). Similarly for chain saw, the velocity of cutting speed (S) at three levels (500, 700 and 900 rpm), the inclination angle of blade (q) at three levels (45, 60 and 90°) and thickness of peduncle (T) three levels (30, 40 and 50 mm) were selected for the experiments. Result: The optimization of the selected levels of variables was done to achieve best performance to select the cutting speed, cutting angle and type of blade. The results showed that circular saw blades with irregular tooth pitch have higher cutting efficiency than circular saw blades with regular tooth pitch. It was found that cutting time increases linearly with decreasing cutting speed. It was observed that chainsaw gives better cut quality with minimum cutting time than saw blades.