Trends and Hybridization Factor for Heavy-Duty Working Vehicles

Reducing the environmental impact of ground vehicles is one of the most important issues in modern society. Construction and agricultural vehicles contribute to pollution due to their huge power trains, which consume a large amount of petrol and produce many exhaust emissions. In this study, several recently proposed hybrid electric architectures of heavy-duty working vehicles are presented and described. Producers have recently shown considerable attention to similar research, which, however, are still at the initial stages of development. In addition, despite having some similarities with the automotive field, the working machine sector has technical features that require specific studies and the development of specific solutions. In this work, the advantages and disadvantages of hybrid electric solutions are pointed out, focusing on the greater electromechanical complexity of the machines and their components. A specific hybridization factor for working vehicles is introduced, taking into account both the driving and the loading requirements in order to classify and compare the different hybrid solutions

Electrified Powertrains for a Sustainable Mobility: Topologies, Design and Integrated Energy Management Strategies

This Special Issue was intended to contribute to the sustainable mobility agenda through enhanced scientific and multi-disciplinary knowledge to investigate concerns and real possibilities in the achievement of a greener mobility and to support the debate between industry and academic researchers, providing an interesting overview on new needs and investigation topics required for future developments

Preliminary design of a hybrid electric powertrain for a earthmoving machine

The goal of this work is to evaluate the benefit of the hybridization of a Compact Wheel Loader (CWL) and to put into evidence the effect of the component size on its performance. To do this, a mathematical model has been developed using a backward approach, i.e. starting from the power request on a typical duty cycle made available by an industrial partner. The goals for the choice of the hybridization architecture were: minimizing fuel consumption, ensuring the simplicity of driveline and power management and ensuring compatibility with the vehicle structure.. A reduction up to 14% of fuel consumption was estimated in this investigation by combining engine downsizing with the usage of a Continuous Variable Transmission together with an optimization of the battery capacity and voltage

Energy Comparison between a Load Sensing System and Electro-Hydraulic Solutions Applied to a 9-Ton Excavator

With the increasingly stringent regulations on air quality and the consequent emission limits for internal combustion engines, researchers are concentrating on studying new solutions for improving efficiency and energy saving even in off-road mobile machines. To achieve this task, pump-controlled or displacement-controlled systems have inspired interest for applications in offroad working machines. Generally, these systems are derived from the union of a hydraulic machine coupled to an electric one to create compact components that could be installed near the actuator. The object of study of this work is a 9-ton excavator, whose hydraulic circuit is grounded on load sensing logic. The validated mathematical model, created previously in the Simcenter Amesim© environment, represents the starting point for developing electro-hydraulic solutions. Electric components have been inserted to create different architectures, both with open-and closed-circuit layouts, in order to compare the energy efficiency of the different configurations with respect to the traditional load sensing system. The simulations of a typical working cycle show the energy benefits of electrohydraulic solutions that allow for drastically reducing the mechanical energy required by the diesel engine and, consequently, the fuel consumption. This is mainly possible because of the elimination of directional valves and pressure compensators, which are necessary in a load sensing circuit, but are also a source of great energy dissipations. The results show that closed-circuit solutions produce the greatest benefits, with higher energy efficiencies than the open-circuit solution. Furthermore, closed-circuit configurations require fewer components, allowing for more compact and lighter solutions, as well as being cheaper

Challenges of micro/mild hybridisation for construction machinery and applicability in UK

In recent years, micro/mild hybridisation (MMH) is known as a feasible solution for powertrain development with high fuel efficiency, less energy use and emission and, especially, low cost and simple installation. This paper focuses on the challenges of MMH for construction machines and then, pays attention to its applicability to UK construction machinery. First, hybrid electric configurations are briefly reviewed; and technological challenges towards MMH in construction sector are clearly stated. Second, the current development of construction machinery in UK is analysed to point out the potential for MMH implementation. Thousands of machines manufactured in UK have been sampled for the further study. Third, a methodology for big data capturing, compression and mining is provided for a capable of managing and analysing effectively performances of various construction machine types. By using this method, 96% of data memory can be reduced to store the huge machine data without lacking the necessary information. Forth, an advanced decision tool is built using a fuzzy cognitive map based on the big data mining and knowledge from experts to enables users to define a target machine for MMH utilization. The numerical study with this tool on the sampled machines has been done and finally realized that one class of heavy excavators is the most suitable to apply MMH technology

Contributions to virtual reality

153 p.The thesis contributes in three Virtual Reality areas: ¿ Visual perception: a calibration algorithm is proposed to estimate stereo projection parameters in head-mounted displays, so that correct shapes and distances can be perceived, and calibration and control procedures are proposed to obtain desired accommodation stimuli at different virtual distances.¿ Immersive scenarios: the thesis analyzes several use cases demanding varying degrees of immersion and special, innovative visualization solutions are proposed to fulfil their requirements. Contributions focus on machinery simulators, weather radar volumetric visualization and manual arc welding simulation.¿ Ubiquitous visualization: contributions are presented to scenarios where users access interactive 3D applications remotely. The thesis follows the evolution of Web3D standards and technologies to propose original visualization solutions for volume rendering of weather radar data, e-learning on energy efficiency, virtual e-commerce and visual product configurators

Energy-saving analysis of hydraulic hybrid excavator based on common pressure rail

Published version of an article in the journal: The Scientific World Journal. Also available from the publisher at: http://dx.doi.org/10.1155/2013/560694 Open AccessEnergy-saving research of excavators is becoming one hot topic due to the increasing energy crisis and environmental deterioration recently. Hydraulic hybrid excavator based on common pressure rail (HHEC) provides an alternative with electric hybrid excavator because it has high power density and environment friendly and easy to modify based on the existing manufacture process. This paper is focused on the fuel consumption of HHEC and the actuator dynamic response to assure that the new system can save energy without sacrificing performance. Firstly, we introduce the basic principle of HHEC; then, the sizing process is presented; furthermore, the modeling period which combined mathematical analysis and experiment identification is listed. Finally, simulation results show that HHEC has a fast dynamic response which can be accepted in engineering and the fuel consumption can be reduced 21% to compare the original LS excavator and even 32% after adopting another smaller engine

A Novel Approach to Hydraulic Drive Sizing Methodology and Efficiency Estimation based on Willans Line

A novel approach to hybrid hydraulic vehicles drive component sizing methodology based on the Willans Line method is proposed in this paper. The proposed method is used to develop a scalable mathematical model of hydraulic unit efficiency maps, thus helping the designer regarding an appropriate hydraulic unit choice when target unit data is difficult to obtain. The hydraulic unit efficiency model is also verified against catalogue data for different unit sizes, and the method is validated by means of detailed approximation error analysis. The proposed method can be particularly useful in optimal component sizing and parameterization studies of hydraulic drives in general, with possible applications to hybrid hydraulic vehicle power-trains