Automação de sistemas hidráulicos de máquinas agrícolas com a utilização de controladores lógicos programáveis

Abstract

This work proposes an automation system using electro-hydraulic valves, and a low-cost Programmable Logic Controller (PLC) to control the operation of agricultural implements. The system will provide the operator and farmers better precision, comfort, versatility, safety and speed, so improving the agricultural production of the adapted machine. Provided that the main objective of precision agriculture is to maximize the efficiency on the usage of raw materials, efficiency will be achieved thing the use of electronic resources (embedded electronics) and tools from informatics in agricultural machines. The automation system proposed foresees the development of a set of programs in Ladder language used in the low-cost PLCs. The electronic control will be used to automate functions executed in agricultural machines such as the plow, sprayer and seeder, also allowing to perform signal processing of sensors, actuators, on-board computers, sprayer controllers, fertilizer controller and satellite mapping. The economic viability of the proposed system takes into consideration the reduction on operational costs, either by productivity increase or by the reduction of the environmental impact caused by excessive use of raw materials, which are typical targets of precision agriculture. The cost of implementation of this system while retrofitting old tractors and agricultural implements also contribute to the economic viability evaluation. Preliminary results were obtained by means of simulation with the FluidSIM software package. Later on the system was be tested in circuits on the hydraulic and pneumatic workbenches available at Unipampa.