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Event
2014-10-07
Fluid power is the best technology for mechanical power transmissions in many applications, including commercial and off-road vehicles. This session focuses on concepts and methods for the simulation of fluid power systems.
Event
2014-10-07
Fluid power is the best technology for mechanical power transmissions in many applications, including commercial and off-road vehicles. This session will present important research aspects related to different hydraulic actuation systems and hydrostatic transmissions. More energy efficient and controllable technologies alternative to current state-of-the-art systems will be presented.
Event
2014-10-07
Topics include the effects of traditional and alternative fuels, and additives on deposit formation, intake system cleanliness, friction, wear, corrosion, and elastomer compatibility. Also covered are effects of fuel specification on drivability, on evaporative emissions, and on the relationship between emissions and drive cycle. In addition, this session covers the analysis, design, testing, and manufacturing techniques and methodologies of all fuel injection systems and their components, including injectors, pumps, rails, lines, connectors, and controls technologies; addressing the areas of power hydraulics, fluid dynamics, strength & durability, performance (steady state & transient), and controls.
Event
2014-10-07
Although not as well-known as their electric siblings, hydraulic hybrid vehicles have made strong progress in recent years. Hydraulics may in fact be the better efficiency solution for many vehicle applications. This session will examine hydraulic hybrid vehicles from research through production ready phases.
Technical Paper
2014-09-30
Francis J. Walker
According to the International Energy Agency (IEA), the United States consumes 20 million barrels of crude oil per day (840,000,000 gallons). More than half of this quantity is imported. It is expected that by 2025 this quantity is expected to rise to 26 million barrels per day with an estimated sixty percent of the consumed quantity being imported. With the prices of oil to continue to be above $90/barrel, the expected annual expenditures on imported oil is estimated to be >$250 billion. With the cost of fossil fuel continuing to increase as its quantity is depleted, there is a strong driver for continued investment in renewable fuel sources. One such approach is the use of plant-based feedstock to augment conventional fossil fuel for diesel applications. Use of such feedstock has given rise to the biodiesel fuel industry (BD). There is little comparative information showing the effects of BD on common sealing materials. Likewise, studies have documented fuel-oil dilution issues in diesel applications.
Technical Paper
2014-09-30
Dileep Gupta
Energy production and consumption are the most crucial aspects for the development of any country. In a row of development; presently, all the countries are passionate towards growth. Subsequently, this appetite of evolution requires a huge amount of energy to fulfill the desire of entire world. Most of the energy is derived from the fossil resources which are extracted from the earth and these resources are depleting day by day because of its in-determinate need for growth and development of any country. It is essential to develop renewable energy resources while considering the impact on environment. In the last decade, demand of alternative fuels has increased a lot. Therefore, researchers have already started working on the aim of developing a green fuel to overcome the future energy demand. And as we know that the biodiesel is generally prepared from the non-edible and renewable resources thus, it can be among the competitive alternative future fuels. Besides that, it does not require any prior engine modifications for its usual advantage among other alternative fuels while using it within certain boundaries.
Technical Paper
2014-09-30
Michael Sprengel, Monika Ivantysynova
Hydraulic hybrid vehicles have demonstrated considerable potential for reducing fuel consumption in on-road and off-highway applications. And while many architectures have been proposed, there still exists room for improvement. Consider the standard series hydraulic hybrid transmission, the high pressure accumulator’s presence necessitates operating the hydraulic units at the current accumulator’s pressure. This often results in the units operating inefficiently at high pressures and low displacements. The accumulator’s high compliance also limits the rate at which system pressure can be increased. In cases where operator torque demand exceeds current system pressure, additional fluid must be pumped into the accumulator. This delay in increasing system pressure (i.e. desired torque) may be perceived by the operator as a spongy or synthetic feel. Finally series hybrids require over center units affixed to the wheels to transition between motoring and pumping modes. Previously the authors proposed a novel hydraulic hybrid architecture, termed a blended hybrid, to address the aforementioned deficiencies.
Technical Paper
2014-09-30
Damiano Padovani, Monika Ivantysynova
Considering that many railway construction machines have a huge mass and perform repetitive working cycles with frequent stops and goes that require precise positioning, a hydraulic propulsion system is a convenient choice. In details, many consolidated solutions make use of valve-controlled hydraulic circuits in which the energy losses have an important impact and dissipative braking is realized. The machine positioning itself is a critical aspect. In some commercialized machines, in fact, an overshoot on the desired final position is reality: therefore, a reverse motion is required in order to match the wanted working point. Clearly, this is a negative characteristic because it introduces unnecessary fuel consumption and slows down the productivity. Moreover, due to the wheel/rail contact, also the limited adhesion is a crucial topic: in details, the propulsion system needs to be capable of reducing the tractive or the braking torque when a loss of adhesion is detected. Consequently, the paper analyzes a hydraulic displacement controlled propulsion system for a railway maintenance machine.
Technical Paper
2014-09-30
Xinyu Ge, Yongli Qi, Kai Zhang
Fuel properties impact the engine out emission directly. For some geographic regions where diesel engines can meet emission regulations without aftertreatment, the change of fuel properties will lead to final tailpipe emission variation. Aftertreatment systems such as Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) are required for diesel engines to meet stringent regulations. These regulations include off-road Tier 4 Final emission regulations in the USA or the corresponding Stage IV emission regulations in Europe. As an engine with an aftertreatment system, the change of fuel properties will also affect the system conversion efficiency and regeneration cycle. Many previous research works focus on prediction of engine out emission, and many are based on chemical reactions. Due to the complex mixing, pyrolysis and reaction process in heterogeneous combustion, it is not cost-effective to find a general model to predict emission shifting due to fuel variation. Some empirical models use testing data as input to locate relationships between controlled inputs and engine response.
Technical Paper
2014-09-30
Vinod Kumar Mannaru, Sunil M Makhe, Lori Stephens, Dinesh Kumar, Shivaprasad Goud
Vapor management system is critical to manage fuel tank capacity, evaporative emissions and pressure control for hybrid applications. Due to stringent emission norms and other regulations there has been lot of advancements in design and application of vapor control valves that are used in automotive fuel tanks. Continuous exposure of these valves to fuel vapor or fuel in some instances led to swelling of assemblies and pose serious threat to product functionality and maintaining required tolerances. Swelling of plastics in fuel is ideally a case of multi physics, which involves modeling of complex mass transfer phenomena. In this study a simple thermal analogous approach has been used to model swelling behavior by characterizing the basic plastic-fuel soaking through coefficient of hygroscopic swelling. Extensive testing has been performed with multiple plastic-fuel combinations with different shapes at different temperatures. Periodic measurements helped to extract coefficients in different directions, which have been used to predict swelling induced strains and stresses in the specimens through finite element analysis.
Technical Paper
2014-09-30
Markus Schneider, Oliver Koch, Juergen Weber
Manufacturers of mobile machinery are currently focusing their development efforts on the increase of machine productivity and operator comfort as well as on the enhancement of energy efficiency and compliance to exhaust emission regulations (EU stage 4, US TIER 4 final). Approaches to meet these goals are the optimization of operating processes, the improvement of the interaction of the system's components and the efficiency increase by use of alternative drive concepts. Within the research project "TEAM - Development of Technologies for Energy-saving Drives of Mobile Machinery" a new energy efficient hybrid drive train for a 24-ton wheel loader with 200 kW installed engine power is developed in order to demonstrate the potential efficiency improvement by use of novel drive technology. An optimized diesel engine, a power-split transmission for the travel drive and a displacement controlled attachment drive are coupled with a hydrostatic parallel hybrid system to replace the conventional drive train.
Technical Paper
2014-09-30
Jiaqi Xu, Bradley Thompson, Hwan-Sik Yoon
Hydraulic excavators perform numerous tasks in the construction and mining industry. Although ground grading is one of the most common tasks, proper grading is not easy to achieve because grading requires an experienced operator to control the boom, arm, and bucket cylinders in a rapid and coordinated manner. Due to this reason, automated grade control is being considered as an effective alternative to conventional human-operated ground grading. In this paper, a path-planning method based on a 2D kinematic model and inverse kinematics is used to determine the desired trajectory of an excavator’s boom, arm, and bucket cylinders. The developed path planning method is programmed and verified by a simple excavator model developed in Simulink/Simscape. For the control of the three cylinders, PID control algorithms are applied. The simulation results show that the automated grade control algorithm can grade level or sloped ground with minimal operation time and error.
Technical Paper
2014-09-30
Bradley Thompson, Hwan-Sik Yoon, Jaehong Kim, Jae Lee
The recent trend of demanding fuel efficient ground vehicles urges off-highway vehicles including construction equipment to be designed more fuel efficient. Among various possibilities, methods to recuperate energy during cab swing motion have been widely examined. Electric and hydraulic hybrids designs have shown to greatly improve fuel efficiency but require drastic changes to the conventional design. The redesigned systems thus require many hours of operation to offset the manufacturing costs with fuel savings. In this research, a relatively simple swing energy recuperation system is presented using an additional accumulator, fixed displacement hydraulic motor, and control valves. In the system, hydraulic fluid is recovered in an accumulator, and a simple controller opens a valve to allow the stored energy to assist the engine in running the main pump. Using various accumulator capacity and hydraulic motor displacement combinations, the recuperation system was simulated for six cycles of a digging and dumping operation.
Technical Paper
2014-09-30
Naseem A. Daher, Monika Ivantysynova
Current power steering systems of off-highway machines suffer from poor energy efficiency, lack of adjustability, passivity relative to the machine’s operating conditions, and are not well poised for a future that will require such machines to be remotely and/or autonomously operated. The authors have proposed, validated, and publicized a novel steer-by-wire technology that resulted in significant energy efficiency increase (43.5%), vehicle speed-dependent steering rate and feel, and active steering intervention relative to yaw moment control in case of incurred lateral instabilities. In this paper, the authors present their work on implementing a remotely operated steering system on a compact wheel loader using an externally mounted joystick via wireless communication protocol. The paper describes the new steer-by-wire system; identifies the required measurements, inputs, and outputs to make the system operational; describes the modules required to enable remote operation; and provides experimental results to show the command tracking of a steering-only maneuver.
Technical Paper
2014-09-30
Pulkit Agarwal, Andrea Vacca, Kelong Wang, Kwang Sun Kim
Radial piston pumps are widely used in hydrostatic transmissions and offer benefits of low noise and high power density. The capability to generate high pressures makes them suitable for clamping function in machine tools and also to operate the presses for sheet metal forming. This study is aimed at developing a comprehensive multi-domain simulation tool to model the lubricating gap flow between the pistons and the cylinder block in a radial piston pump with rotating cam type design. The model consists of a first module which simulates the main flow through the unit according to a lumped parameter approach. This module evaluates the features of the displacing action accounting for the detailed evaluation of the machine kinematic and for the mechanical dynamics of the check valves used to control the timing for the connection of each piston chamber with the inlet and outlet port. The estimation of the instantaneous pressure within each displacement chamber is utilized in a second module dedicated to the prediction of the lubricating gap flow between the pistons and the cylinder.
Technical Paper
2014-09-30
Marco Carriglio, Alberto Clarich, Rosario Russo, Enrico Nobile, Paola Ranut
Nowadays the design and production of Heat Exchangers (HE) is a well-established process based on robust and, somehow, rigid procedures. The technology is based on golden rules which, since the publication of the Kays and London book on Compact HE, are the basis for the design process. Even when optimization studies are performed, these are frequently based on a performance evaluation criterion (PEC), i.e. a single scalar representing the performance of the heat exchanger, instead of considering the multiple objectives simultaneously. The main purpose of this study is the development of an innovative methodology for HE design to replace the conventional design procedures. The new procedure is based on the definition of a software package managed by modeFRONTIER, a multi-objective optimization software produced by ESTECO, able to create HE virtual models by targeting several objectives, like HE performance, optimal use of material, HE minimal weight and size and optimal manufacturability.
Technical Paper
2014-09-30
Xiangang Wang
Experiments were conducted in a turbocharged, high-pressure common rail diesel engine to investigate particulate emissions from the engine fueled with biodiesel and diesel blends. An electrical low-pressure impactor (ELPI) was employed to measure the particle size distribution and number concentration. Heated dilution was used to suppress nuclei mode particles and focus on accumulation mode particles. The experiment was carried out at five engine loads and two engine speeds. Biodiesel fractions of 10%, 20%, 40%, 60% and 80% in volume were tested. The study shows that most of the particles are distributed with their diameters between 0.02 and 0.2 μm, and the number concentration becomes quite small for the particles with the diameters larger than 0.2 μm. With the increase of biodiesel fraction, engine speed and/or engine load, particle number concentration decreases significantly, while the particle size distribution varies little. The analysis on heat release rate, excess air ratio and exhaust gas temperature were provided to help interpret the particulate emissions.
Training / Education
2014-08-18
Hydraulic brake systems, one of the most important safety features on many road vehicles today, must meet manufacturer and customer requirements in addition to Federal Motor Vehicle Safety Standards. This course will analyze automotive braking from a system's perspective, emphasizing legal requirements as well as performance expectations such as pedal feel, stopping distance, fade and thermal management. Calculations necessary to predict brake balance and key system sizing variables that contribute to performance will be discussed. Major components of a brake system, including calipers, boosters, master cylinders, drum brakes, and park brakes will be presented in detail highlighting the many design variations. An overview of the chassis control components and operating principles will be presented with an emphasis on ABS, traction control and stability control. This course has been approved by the Accreditation Commission for Traffic Accident Reconstruction (ACTAR) for 18 Continuing Education Units (CEUs).
WIP Standard
2014-07-15
This document provides recommended practices for the design of tubing systems that are used for the transmission of liquid and gasses in fluid power systems for aerospace vehicles such as aircraft, missiles and boosters. The primary emphasis is given to recommended practices for line sizing, tube routing, supports and clamping, stress considerations and permissible defects, and provisions for flexure through the use of flexible hoses, coiled tubes, swivel joints, and expansion glands. The sections regarding tubing materials and fitting types are included for reference, but particular recommendations are purposely avoided since their selection is dependent upon the specific requirements of each particular vehicle system and many other factors. Fluid power systems are differentiated from the normal aircraft fuel and oil systems and the various fluid systems used for environmental control and air conditioning systems; however, the practices cited herein will in many cases be applicable to these other systems.
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