Reducing fuel consumption in weed and pest control using robotic tractors

© 2015 Elsevier B.V. A significant problem exists concerning contamination of the environment, especially air pollution, and the consequent climatic change. Considering that agricultural vehicles that use fossil fuels emit significant amounts of atmospheric pollutants, the main objective of this paper is to include techniques to reduce the fuel consumption in the controls system of robotic tractors used in agriculture tasks and thereby reduce the atmospheric emissions from these automated applications. To achieve this goal, the first step is to analyze fuel consumption in real time for each of the applications to be improved and to implement the consumption model of a robotic tractor for each task, considering the mechanical energy variations, the performance losses, the energy used to overcome friction and the energy required by the given task. For calculating the mechanical energy, the model considers the potential energy of the system, which is a function of the mass, elevation and gravity. The terrain elevations are estimated from GeoTIFF images of DEM data, which have a pixel size equal to 1. arc second (approximately 30. m at the Equator), and an accuracy of integer meters. Regarding the system mass, the possible loss of mass from applying the treatment is considered. For estimating the frictional forces, the rolling resistance coefficient of the terrain surface conditions is used.The consumption model has been validated experimentally using real agricultural vehicles and implements within the RHEA project (FP7-NMP 245986), in which the instantaneous fuel consumption was measured.This fuel reduction method is applied to three different treatments: weed control on herbaceous crops through the spraying of herbicides, weed control on fire-resistant crops with wide furrows through plowing and flame treatment, and pest control on trees through fumigation using insecticides.Finally, a fuel reduction procedure is applied to each task using the system model implemented to predict the energy requirements. This enables one to find the optimum path plan with respect to fuel consumption. These theoretical results are compared with the experimental results. In addition, the goal is to demonstrate the fuel reduction technique by performing field experiments to show that the use of this method of fuel reduction leads to an reduced fuel consumption and thus reduces atmospheric emissions from agricultural tasks. The results obtained revealed that this fuel reduction method significantly reduces the energy requirements, with the consequent reduction in fuel consumption and atmospheric pollutant emissions.The research leading to these results received funding from the European Union’s Seventh Framework Programme [FP7/2007-2013] under Grant Agreement n. 245986.Peer Reviewe