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Site Specific Costs Concerning Machine Path Orientation
M. Spekken, J. P. Molin, T. L. Romanelli, M. N. Ferraz
University of São Paulo

Computer algorithms have been created to simulate in advance the orientation/pattern of a machine operation on a field. Undesired impacts were obtained and quantified for these simulations, like: maneuvering and overlap of inputs in headlands; servicing of secondary units; and soil loss by water erosion. While the efforts could minimize the overall costs, they disregard the fact that these costs aren’t uniformly distributed over irregular fields. The cost of a non-productive machine process (like maneuvering) is minor when it is distributed along a lengthy working track, yet can be profit-compromising for a short track. Also, these tracks hardly follow the terrain contours perfectly, leading to regions more prompt to soil loss. Hence the path orientation affects the length and the surface grade of a track, the intensity and location of the impacts will also be altered. An application was developed to create machine tracks on irregular surfaces and estimate quantities of soil loss within segments of the tracks. Procedures were embedded into the algorithm to calculate costs of maneuvering space, length, time and overlap by the use of geometric equations. A procedure was added assign a cost to a track when its length unable a precise depletion/completion of the tank’s content (of fertilizer for e.g.) when reaching the field boundaries/roads. Two case studies of distinct crops and machine properties were processed by the algorithm in a specific pattern searching minimal soil loss. In a sugarcane study, the model obtained that for the average of five harvests, 2.69% of the area presented negative turnover due to the path orientation impacts; however, this area increases tenfold when financial balance is calculated for the last two harvests of the crop. In a cotton case study, a high input cost was calculated for overlap of applied products in headland; with the adoption of a section control boom for the spraying operation, a significant reduction of costs up to US$ 50.00 per hectare was obtained. Considering the costs owed to path establishment these cannot be ignored in economic spatial studies given its role in compromising revenue in certain regions of the field.

Keyword: Path planning, Spatial cost distribution, Soil loss impact, Machine efficiency