A Model-Based Design Approach for a Parallel Hybrid Electric Tractor Energy Management Strategy Using Hardware in the Loop Technique

Abstract

Recent developments in emissions regulations are pushing Non-Road Mobile Machineries manufacturers towards the adoption of more efficient solutions to reduce the amount of pollutants per unit of work performed. Electrification can be a reasonable alternative to traditional powertrain to achieve this goal. The higher complexity of working machines architectures requires, now more than ever, better design and testing methodologies to better integrate electric systems into mechanical and hydraulic layouts. In this work, the attention focused on the use of a Hardware in the Loop (HIL) approach to test performance of an energy management strategy (called load observer) developed specifically for an orchard tractor starting from field characterization. The HIL bench was designed to replicate a scaled architecture of a parallel hybrid electric tractor at mechanical and electrical level. The vehicle behavior was simulated with a personal computer connected on the CAN BUS network designed for the HIL system. Several tasks were simulated starting from data gathered during field measurements of a daily use of the machine. Results showed good performance in terms of load split between the two power sources and stability of the speed control although the variability of the applied load.

Wheel Slip Control Applied to an Electric Tractor for Improving Tractive Efficiency and Reducing Energy Consumption

“…The first step consists in obtaining the system model using a parametric identification method based on data measured from the electric tractor. The model parameters are Vx and VW, which were collected during experimental tests so that it is possible to represent the plant in the form of an auto-regressive with exogenous input (ARX) structure, corresponding to the transfer function given in Equation (7) [27]. The first step consists in obtaining the system model using a parametric identification method based on data measured from the electric tractor.…”

“…The performance evaluation of agricultural electric tractors and their respective control strategies have also been the scope of some works focused on the introduction of accurate numerical models [6]. In this context, efficient energy management strategies combined with proper software and hardware tools are essential to optimize such novel powertrains [7].…”

Modeling of an Electric Tractor and Determining Energy Consumption Values In Different Duties

“…The energy consumption values of the electric tractor in rotary harrow, atomizer, and shredder duties were obtained. Since there are no standard test procedures established for the duties of the electric tractor, the cycle values of the duties are taken from the reference source [26,27]. The speed and torque cycles of the duties were created by making the necessary adjustments in the referenced graphics.…”

Comparative Analysis of Hybrid Electric Architectures for Specialized Agricultural Tractors

“…The proposed working scenarios involved both transportation with trailer and field operations with several types of implements attached to the machine. An average energy saving of 17% was obtained by the proposed architecture using a load observer control strategy, which was then tested by Mocera [19] on a real hardware platform in a hardware-in-the-loop (HIL) test bench configuration. Several studies are also available in the literature on series HET architectures.…”