New Hydraulic Control Technologies for Improving the Energy Efficiency of the Hydraulic System of Agricultural Tractors and Their Implements

This paper describes two alternative methods to achieve the goal of reducing the fuel consumption of the high-pressure hydraulic control system of agricultural tractors and their implements. The first approach consists of a re-visitation of the basic load sensing (LS) technology used to power the hydraulic remotes. Namely, the metering regulations proper of a LS system is shifted from the tractor remote valves to the implement control valves. The second approach instead converts the hydraulic supply from a flow-based control logic (like in the LS system) to a pressure-based control. In different ways, both methods allow eliminating the conflicts existing between the tractor control valves and the implement ones, which cause excessive pressurization of the supply pumps and therefore high throttling losses. The proposed methods are properly analyzed in simulation, and then tested considering reference of a 390 hp tractor and a 16-row planter. The results show a high improvement in energy performance for both the proposed solutions. With respect to the commercial system considered as the baseline, both solutions allow increasing the energy efficiency by more than 38%, with variations that depend on the operating conditions.