Coupling excavator hydraulic system and internal combustion engine models for the real-time simulation

Rising energy costs and emissions restrictions force manufacturers to exploit new techniques to reduce fuel consumption and pollutant production. Many solutions have been proposed for off-road vehicles, mainly based on reduction of hydraulic losses, better control strategies and introduction of hybrid architectures. In these applications the optimization of the matching between hydraulic system and thermal engine is a major concern to improve system overall efficiency. The work presented in the paper is focused on the development of a method for the simulation of typical mobile machinery where hydraulic systems are powered by internal combustion engines; the proposed co-simulation approach can be useful in the development cycle of this machinery

Development and Application of Co-simulation and "Control- oriented" Modeling in the Improvement of Performance and Energy Saving of Mobile Machinery☆

Abstract Due to rising energy costs and tighter emissions restrictions from law regulations, mobile machinery and off-road vehicles manufacturers are forced to develop and exploit new techniques for the reduction of fuel consumption and pollutant emission. The main focus in this direction is the optimization of the matching between the fluid power circuit and the thermal engine to improve the efficiency of the hydraulic system and reducing the fuel consumption. A specific research activity has been started in this field by the authors to define methods and techniques for the mathematical simulation of off-road vehicles, where usually hydraulic systems are powered by internal combustion engines. The models proposed in the paper and the related results clearly show how these simulation tools can be used to improve the energy efficiency of the overall system, leading to an interesting reduction in fuel consumption by merely changing the engine rotational speed instead of adopting a constant-speed strategy

Energy saving solutions for a hydraulic excavator

Abstract Nowadays the improvement of energy efficiency and the reduction of pollutant emissions are the major challenges that the mobile machinery manufacturers have to face with. With rising fuel prices and increasingly stringent regulations, the development of energy saving solutions and efficient hydraulic system have become a priority for researchers and OEM's. One of the most effective approach is the machine hybridization but other solutions can be adopted. This paper proposes with the aid of mathematical tools energy saving solutions for an excavator equipped with a load sensing hydraulic system. A comprehensive energy analysis was conducted through the excavator model to highlight the energy dissipations along the system. Different solutions to reduce losses and improve fuel saving including energy recovery from boom and arm and the introduction of a second pump in the flow generation unit were identified and investigated in detail. Finally, combining the proposed solutions, a new hydraulic hybrid excavator concept was obtained with a 15% of fuel saving

Hydraulic Hybrid Excavator: Layout Definition, Experimental Activity, Mathematical Model Validation and Fuel Consumption Evaluation

Energy saving and fuel consumption reduction techniques are among the principal interests for both academic institutions and industries, in particular, system optimization and hybridization. This paper presents a new hydraulic hybrid system layout for mobile machinery implemented on a middle size excavator. The hybridization procedure took advantage of a dynamic programming (DP) algorithm, which was also utilized for the hybrid components dimensioning and control strategy definition. A dedicated experimental activity on test bench was performed on the main components of the energy recovery system (ERS). The JCMAS working cycle was considered as the reference test for a fuel consumption comparison between the standard and the hybrid excavator. A fuel saving up to 8% on the JCMAS cycle, and up to 11% during the digging cycle, has been allowed by the proposed hybrid system

Use of Sugar Dispensers to Disrupt Ant Attendance and Improve Biological Control of Mealybugs in Vineyard

Planococcus ficus (Signoret) and Pseudococcus comstocki (Kuwana) (Hemiptera: Pseudococcidae) are economically important pests occurring in vineyards, causing severe economic losses for growers and compromising bunch production. The partial effectiveness of insecticides used in controlling mealybug infestations as well as their high impact on the environment and on human health have led to the research of alternative and sustainable control methods, including biological control. Several natural enemies are reported to be effective against mealybugs, but their activity may be hindered by tending ants. These social insects are known to exhibit a mutualistic relationship with mealybugs, resulting in extremely aggressive behavior against beneficial insects. Consequently, this study explored a method to mitigate ant attendance by means of sugar dispensers in order to improve ecosystem services, as well as decrease mealybug infestation in vineyards. Field trials were carried out in four commercial vineyards of Northern Italy infested by mealybugs, in which Anagyrus vladimiri Triapitsyn (Hymenoptera: Encyrtidae) and Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) were released as biological control agents. Our results showed that sugar dispensers reduced ant activity and mealybug infestation, leading to a significant enhancement of ecosystem services. The technique showed a great potential in boosting biological control against mealybugs in field conditions, though the field application seemed to be labour intensive and needs to be replicated for a multi-year evaluation

Combination of a Solvent-dispensing and Micro-aspiration Device for Removal of Varnishes on Painted Surfaces

The use of organic solvents in treatments for the removal of varnishes on easel paintings is still a common practice among conservators worldwide. The more polar solvents required for aged, oxidized varnishes may promote leaching of fatty acid components of oil-based paints. The strategy tested in this study to reduce the diffusion of the solvents, in an attempt to minimize interactions, relied on the use of a system composed of two devices: a pump for delivering a precisely controlled amount of solvent to the surface, and a solvent-proof membrane pump to quickly aspirate it. This method was compared with two traditional methods of solvent application, to remove the varnish on two oil paintings on canvas, one from the twentieth century and the other dated 1872: swab-rolling and application through a Japanese paper sheet. The extent of leaching was measured by GC−MS analysis of the paint samples taken from the treated areas. The profiles of the fatty acids before and after varnish removal could thus be compared

Coastal benthic habitat mapping and monitoring by integrating aerial and water surface low-cost drones

Accurate data on community structure is a priority issue in studying coastal habitats facing human pressures. The recent development of remote sensing tools has offered a ground-breaking way to collect ecological information at a very fine scale, especially using low-cost aerial photogrammetry. Although coastal mapping is carried out using Unmanned Aerial Vehicles (UAVs or drones), they can provide limited information regarding underwater benthic habitats. To achieve a precise characterisation of underwater habitat types and species assemblages, new imagery acquisition instruments become necessary to support accurate mapping programmes. Therefore, this study aims to evaluate an integrated approach based on Structure from Motion (SfM) photogrammetric acquisition using low-cost Unmanned Aerial (UAV) and Surface (USV) Vehicles to finely map shallow benthic communities, which determine the high complexity of coastal environments. The photogrammetric outputs, including both UAV-based high (sub-meter) and USV-based ultra-high (sub-centimetre) raster products such as orthophoto mosaics and Digital Surface Models (DSMs), were classified using Object-Based Image Analysis (OBIA) approach. The application of a supervised learning method based on Support Vector Machines (SVM) classification resulted in good overall classification accuracies > 70%, proving to be a practical and feasible tool for analysing both aerial and underwater ultra-high spatial resolution imagery. The detected seabed cover classes included above and below-water key coastal features of ecological interest such as seagrass beds, “banquettes” deposits and hard bottoms. Using USV-based imagery can considerably improve the identification of specific organisms with a critical role in benthic communities, such as photophilous macroalgal beds. We conclude that the integrated use of low-cost unmanned aerial and surface vehicles and GIS processing is an effective strategy for allowing fully remote detailed data on shallow water benthic communities

Halyomorpha halys in Emilia, prime risposte dal monitoraggio

OSSERVAZIONI IN CAMPO CONDOTTE NEL 2013-2014. Dopo la sua comparsa in Italia, accertata nel 2012, è stato attivato nella zona di ritrovamento un programma di monitoraggio teso a studiare l’insetto e il suo comportamento nell’ambiente. La specie desta maggiori preoccupazioni nel settore frutticolo, dove il danno rappresentato dalle tipiche deformazioni può giungere al 100

Population dynamic of the extinct European aurochs: genetic evidence of a north-south differentiation pattern and no evidence of post-glacial expansion

<p>Abstract</p> <p>Background</p> <p>The aurochs (<it>Bos primigenius</it>) was a large bovine that ranged over almost the entirety of the Eurasian continent and North Africa. It is the wild ancestor of the modern cattle (<it>Bos taurus</it>), and went extinct in 1627 probably as a consequence of human hunting and the progressive reduction of its habitat. To investigate in detail the genetic history of this species and to compare the population dynamics in different European areas, we analysed <it>Bos primigenius </it>remains from various sites across Italy.</p> <p>Results</p> <p>Fourteen samples provided ancient DNA fragments from the mitochondrial hypervariable region. Our data, jointly analysed with previously published sequences, support the view that Italian aurochsen were genetically similar to modern bovine breeds, but very different from northern/central European aurochsen. Bayesian analyses and coalescent simulations indicate that the genetic variation pattern in both Italian and northern/central European aurochsen is compatible with demographic stability after the last glaciation. We provide evidence that signatures of population expansion can erroneously arise in stable aurochsen populations when the different ages of the samples are not taken into account.</p> <p>Conclusions</p> <p>Distinct groups of aurochsen probably inhabited Italy and northern/central Europe after the last glaciation, respectively. On the contrary, Italian and Fertile Crescent aurochsen likely shared several mtDNA sequences, now common in modern breeds. We argue that a certain level of genetic homogeneity characterized aurochs populations in Southern Europe and the Middle East, and also that post-glacial recolonization of northern and central Europe advanced, without major demographic expansions, from eastern, and not southern, refugia.</p