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To reduce the impact of the agricultural sector on the environment, human health and resource depletion, several steps should be taken to develop innovative powertrain systems. The agricultural sector must be involved in this innovation, since diesel-powered tractors are an important source in terms of pollution. In this context, fuel-cell systems have gained importance, making them one of the possible substitutes due to their characteristics featuring almost zero local emissions, low refueling time and high efficiency. However, to effectively assess the sustainability of a fuel-cell tractor, a cradle-to-grave life cycle assessment, comprising production, use phase and end of life, must be performed. This article presents a comparative analysis, according to different impact categories, of the life cycle impacts of a traditional diesel-powered tractor and a fuel-cell hybrid tractor, designed considering operative requirements and functional constraints. The study was conducted according to the LCA technique (defined by ISO 14040 and ISO 14044 standards), combining secondary data, mainly derived from studies and reports available in the literature, with the use of the Ecoinvent 3.0 database. The results are presented according to ten different impact categories defined by ReCiPe 2016 v 1.03 at the midpoint level. The findings obtained showed that the fuel-cell tractor allows for a relevant reduction in all the considered categories. The highest-impact reduction, more than 92%, was obtained in the human toxicity non-carcinogenic category, while the lowest reduction, around 4.55%, was observed for the fossil fuel scarcity category, mainly due to the adoption of gray hydrogen which is produced from fossil fuels. As for the climate change category, the fuel-cell tractor showed a reduction of more than 34% in the life cycle impact. Finally, the authors also considered the case of green hydrogen produced using solar energy. In this case, further reductions in the impact on climate change and fossil fuel resource depletion were obtained. However, for the other impact categories, the results were worse compared to using gray hydrogen. [ABSTRACT FROM AUTHOR]

Recently, the agriconstruction machinery sector has been involved in a great technological revolution. The reasons that may explain this are strictly connected to the mitigation of climate change. At the same time, there is a necessity to ensure an adequate production level in order to meet the increasing food demand due to the current population growth trend. In this context, the development of autonomously driven agricultural vehicles is one of the areas on which tractor manufacturers and academics are focusing. The fundamental prerequisite for an autonomous driving vehicle is the development of an appropriate motion strategy. Hence, the vehicle will be able to follow predetermined routes, accomplishing its missions. The aim of this study was the development of path-planning and path-following algorithms for an agricultural four-whee differential-drive vehicle operating in vineyard/orchard environments. The algorithms were completely developed within the MATLAB software environment. After a brief description of the geometrical characteristics of the vehicle, a parametric process to build a virtual orchard environment is proposed. Then, the functional principles of the autonomous driving algorithms are shown. Finally, the algorithms are tested, varying their main tuning parameters, and an indicator to quantify the algorithms' efficiency, named relative accuracy, is defined. The results obtained show the strong dependence between the relative accuracy and lookahead distance value assigned to the rover. Furthermore, an analysis of rover positioning errors was performed. The results in this case show a lower influence of the location error when the accuracy of the positioning device is within 2 cm. [ABSTRACT FROM AUTHOR]

The effects of climate change are reaching a point of no return. The necessity to reduce greenhouse gasses (GHGs) is currently notorious on several levels: academic, industrial, and political. The Paris Climate Agreement set a clear roadmap to limit pollutant emissions and reach carbon neutrality. Consequently, everything related to product life cycles, considering the entire supply chain, needs to be analyzed and reconsidered. The agricultural sector is no exception: indeed, it is responsible for 11% of global anthropogenic GHG emissions. Agri-construction sector accounts for 20–30% of all GHG emissions referred to the agricultural field. This study aimed to evaluate the GHG emissions of an orchard-specialized tractor operating in Europe considering a service life of ten years. The assessment was conducted through the life-cycle assessment (LCA) standardized methodology, combining secondary data, primary data, and a software database (Open LCA (v 1.10.3) software, Environmental Footprint (v 4) database). First, the functional unit, and the boundaries of the analysis are defined. Then, the tractor life cycle is analyzed considering its three main stages: manufacture, use, and disposal. Lastly, the results are discussed according to gate-to-gate and cradle-to-gate approaches. What emerged from the assessment was the production of 5.75 kg CO2eq. · kgvehicle−1 · year−1 for a single orchard specialized tractor and the predominance of use phase emissions (around 90% of the total). [ABSTRACT FROM AUTHOR]

Vehicles for planetary exploration have to operate in completely different environments from Earth. For this reason, the design process of the exploration unit has an important role and can affect the requirements of the entire mission for the different space agencies involved. These operations are very expensive and time consuming, so that, over the years, ad hoc CAE methods have been developed to help engineers in the design stage. These methods are used to simulate several working conditions, evaluating which manoeuvres robots can safely perform during their mission. In this framework, a study was performed by Politecnico di Torino and Thales Alenia Space Italia. The goal was to find an efficient way to implement flexibility properties of a special wheel of a Rover for Martian explorations in a commercial (general purpose) MTB code. The ExoMars Rover was considered as case study of this work. When dealing with manoeuvres feasibility analysis, the best compromise between solution accuracy and computational time required must be found. The aim of this study was to explore pros and cons of several techniques which could allow modelling a complex flexible wheel using a commercial general-purpose MTB code. The absolute nodal coordinate formulation was compared with the other reduced-order modelling strategies proposed by the authors to implement the flexibility of a wheel in a multibody model of the full vehicle. Numerical results show good performance of the reduced morphing model in terms of computational time versus numerical accuracy. [ABSTRACT FROM AUTHOR]