The Hydraulic Power Generation and Transmission on Agricultural Tractors: feasible architectures to reduce dissipation and fuel consumption – Part I

Abstract

This paper is aimed at investigating the benefits in terms of energy efficiency of new electro-hydraulic architectures for power distribution systems of a medium-size agricultural tractor, with a focus on the hydraulic high-pressure circuit. The work is part of a wider industrial research project called TASC (Smart and Clean Agricultural Tractors [1]). Traditional and alternative architectures have been modelled and energetically compared through simulation, using a lumped parameter approach. Experimental data previously acquired have been used to validate the models and to replicate real working conditions of the machine in the simulation environment. A typical on-field manoeuvre has been used as duty cycle, to perform an effective energetic analysis. The standard hydraulic circuit is a multi-users load sensing system that uses a single variable displacement pump to feed steering, trailer brake and auxiliary utilities in that order. The key idea of the proposed solutions is the separation of steering from the other implements, to optimize the entire energy management. In particular, the paper investigates new and flexible solutions for the auxiliary utilities, including an electro-hydraulic load sensing architecture with variable pump margin, an electronic flow matching and flow sharing architecture, and an electronic strategy for automatic pressure compensation. The simulation results show that good energy saving can be achieved with the alternative architectures, so that physical prototyping of the most promising solutions will be realized as next step of the project.

Comprehensive lumped parameter and multibody approach for the dynamic simulation of agricultural tractors with tyre–soil interaction

“…Gaiola et al. [4] investigated new and flexible solutions to increase the efficiency of the hydraulic system through a lumped parameter method. A wide variety of studies deal with modelling suspension systems and tyre–soil interactions to assess handling and comfort characteristics.…”

“…Zardin et al [3] proposed a modelling and analysis tool for the simulation of a hydrostatic steering system to assess its performance and determine the influence of its main design parameters on energy dissipation. Gaiola et al [4] investigated new and flexible solutions to increase the efficiency of the hydraulic system through a lumped parameter method. A wide variety of studies deal with modelling suspension systems and tyre-soil interactions to assess handling and comfort characteristics.…”

Multi-Point-of-View Energy Loss Analysis in a Refuse Truck Hydraulic System

“…Examples of variations of the traditional load-sensing architecture to improve its efficiency are the flow-on-demand load-sensing (FOD) proposed in [4] and the electronic loadsensing (ELS) shown in [5]. Some LS variations are investigated in [6,7] on a medium-sized agricultural tractor.…”

Excavator hydraulic circuit solution to reduce dissipations and fuel consumption

“…Other aspects concern the optimization of power transmission [6][7][8] without neglecting the importance of the optimal match between the hydraulic system and the thermal engine [9]. Mathematical models are necessaries for evaluating different solutions, the models could be based on lumped parameters approach for the systems simulation [10][11][12][13][14][15] while when a component needs to be optimized dedicated detailed models should be developed; the literature reports research activities carried out on gear pumps [16][17][18][19][20][21]; fixed displacement gerotor pump are investigated in [22][23][24][25][26][27]. Particular applications like lubrication pump are investigated in [28][29][30]; topics concerning the condition monitoring applied to hydraulic pumps are reported in [31,32]; other papers are focused on detailed analysis of hydraulic valves [33][34][35].…”