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Viewing 1 to 30 of 19192
2016-09-27
Technical Paper
2016-01-8006
John Reid, Stewart Moorehead, Alex Foessel, Julian Sanchez
A transformation of agriculture began reached commercial maturity at the beginning of this century that has provided increased customer value from the basis of automating steering system control in crop production systems. The maturity of this technology has led to increased machine system productivity over the last decade leading to increasingly integrated solutions with increased customer value in terms of comfort and productivity. This sets agricultural production ecosystem on a course of new forms of innovation opportunity at the worksite level that is being greatly accelerated by the maturity of the technologies supporting cyber-physical systems. This paper will review the progress from the perspective of the customer value and the industry execution of autonomous driving technologies and will describe the pathways to autonomous worksites, in addition to the challenges to the industry with the emergence of new business models for autonomy.
2016-09-27
Technical Paper
2016-01-8148
Louis Carbonne, Niklas Winkler, Gunilla Efraimsson
The prediction in the design phase of the stability of ground vehicles subject to transient crosswinds become of increased concern with drag reduced shapes, platooning as well as lighter vehicles. The objective of this work is to assess the order of model complexity needed in numerical simulations to capture the behavior of a ground vehicle going through a transient crosswind. The performance of a full-dynamic coupling between aerodynamic and vehicle dynamic simulations, including a driver model, is evaluated. In the simulations a feedback from the vehicle dynamics into the aerodynamic simulation are performed in every time step. In the work, both the vehicle dynamics response and the aerodynamics forces and moments are studied. The results are compared to a static coupling approach on a set of different vehicle geometries.. One simplified bus geometry and five car-type geometries are evaluated.
2016-09-27
Technical Paper
2016-01-8012
Daniel E. Williams, Amine Nhila, Kenneth Sherwin
A large percentage of commercial vehicles transport freight on our interstate highway system. These vehicles spend the vast majority of their duty cycle at high speed maintaining a lane. As steering is integrated into ADAS, objective performance measures of this most common mode of commercial vehicle operation will be required. Unfortunately in the past this predominant portion of the commercial vehicle duty cycle was overlooked in evaluating vehicle handling. This lanekeeping mode of operation is also an important, although less significant portion of the light vehicle duty cycle. Historically on-center handling was compromised to achieve acceptable low speed efforts. With the advent of advanced active steering systems, this compromise can be relaxed. Objective measures of lanekeeping are developed and performance of various advanced steering systems is quantified in this important operating mode.
2016-09-27
Technical Paper
2016-01-8027
Stefan Steidel, Thomas Halfmann, Manfred Baecker, Axel Gallrein
Rolling resistance and tread wear of tires do particularly influence the maintenance costs of commercial vehicles. Although the tire labeling is established in Europe, it is meanwhile well-known that, due to the respective test procedures, these labels do not hold in realistic application scenarios in the field. This circumstance arises from the development phase of tires, where the respective performance properties are mainly evaluated in tire/wheel standalone scenarios in which the wide range of usage variability of commercial vehicles cannot be considered adequately. Within this article we address a method to predict indicators for rolling resistance and tread wear of tires in realistic application scenarios considering application-based factors of influence like specific customers, operation circumstances, regional dependencies, fleet specific characteristics etc. Moreover, the prescribed methodology may also be transferred to the prediction of fuel consumption and emission.
2016-09-27
Technical Paper
2016-01-8061
Thomas Howell, Bruce Swanbon, Justin Baltrucki, Alan Steines, Nancy Neff, Biao Lu
Heavy duty valvetrains continue have evolved over the last 20 years with the integration of engine braking into the valvetrain. Jacobs Vehicle Systems have developed the High Power Density engine brake that doubles the low speed retarding power and increases high speed retarding power. The system works by converting the engine from a 4 stroke during positive power into a 2 stroke for retarding. This provides substantial retarding power at cruise engine speeds reducing the need to downshift in order to control the vehicle, compensates for reduction in natural vehicle retarding due to aerodynamic and friction enhancements, and enables the same vehicle retarding power with a smaller displacement engine as engine downsizing becomes prevalent.
2016-09-27
Technical Paper
2016-01-8011
Kevin Grove, Jon Atwood, Myra Blanco, Andrew Krum, Richard Hanowski
The goal of this research was to investigate the reliability of tractor-trailer collision avoidance systems (CASs) and characterize the activations observed in the real world. 150 commercial tractor-trailers were equipped with a data acquisition system (DAS) for up to one year. The DAS recorded video of the roadway, video of the driver and vehicle data whenever the truck was driving. Data was collected between November 2013 and August 2015, and the trucks in the study were equipped with either the Meritor WABCO OnGuardTM or Bendix® Wingman® AdvancedTM products. Seven companies from across the United States participated in the study, and all participating vehicles drove their normal, revenue-producing routes. The study evaluated reliability by classifying activations into three categories, based on whether a valid object was being tracked and whether the driver need to react immediately to the activation.
2016-09-27
Technical Paper
2016-01-8113
Xiaohua Zeng, Guanghan Li, Dafeng Song, Sheng Li, Xianghua Li
This paper introduces the configuration and operation principle of the hydraulic hub-motor auxiliary system for heavy truck, which could achieve auxiliary driving and auxiliary braking function. In order to achieve coordinate distribution of the engine power between mechanical and hydraulic system, the hydraulic pump displacement controller is designed. A layered auxiliary drive control strategy is proposed to improve vehicle performance. Finally, the simulation model is built in the MATLAB/Simulink and AMESim platform and the co-simulation is conducted to verify the proposed control strategy. The results show that the strategy could realize effective control and the traction force increased proportion can be up to 15.6~17%, which would significantly improve the drivability and passing capacity of heavy truck.
2016-09-27
Technical Paper
2016-01-8147
Justin J. Novacek, Bhargav Sowmianarayanan
Trailer positioning plays a significant role in the overall aerodynamics of a tractor-trailer combination and varies widely depending on configuration and intended use. In order to minimize aerodynamic drag over a range of trailer positions, adjustable aerodynamic devices like a trim tab may be utilized. For maximum benefit, it is necessary to determine the optimal position of the aerodynamic device for each trailer position. This may be achieved by characterizing a two-dimensional design space consisting of trailer height and tractor-trailer gap length, with aerodynamic drag as the response. CFD simulations carried out using a Lattice-Boltzmann based method were coupled with modeFRONTIER for the creation of multiple Kriging Response Surfaces. These response surfaces were employed to generate an optimal positioning map for the given aerodynamic device. This methodology was further refined by obtaining performance maps for multiple tractor configurations.
2016-09-27
Technical Paper
2016-01-8028
Chao Yang, Nan Xu, Konghui Guo
This paper focuses on the modeling process of incorporating inflation pressure into the UniTire tire model for pure cornering. Via observing and manipulating the tire experimental data, the effects of inflation pressure on the tire cornering property are analyzed in detail, including the impacts on cornering stiffness, the peak friction coefficient, the curvature of transition region and the pneumatic trail. And the brief mechanism explanations are also given for some of those impacts. The results show that some effects of inflation pressure are similar to that of vertical load on the non-dimensional tire cornering property, and also have strong interactive effects between the two operating conditions. Therefore, in order to obtain concise expressions, the inflation pressure is incorporated into the UniTire tire model by analogy with the expressions for vertical load, and the interactive effects are also taken into account.
2016-09-27
Technical Paper
2016-01-8055
Rohit Saha, Long-Kung Hwang, Mahesh Madurai Kumar, Yunfeng Zhao PhD, Chen Yu, Bob Ransijn
Wheel-loaders’ sub-systems like engine, driveline, hydraulics, cooling and mechanism are becoming increasingly more integrated and complex. This is mostly caused increased demand of energy efficiency, electronic controls and performance requirements from competitors and customers. In order to understand the complex sub-system interactions it requires engineers to use a common simulation platform which captures the multi-domain nature of a wheel-loader. Engineers from different sub-system groups can use such model to validate the full system requirements. Wheel-loader sub-system are multi-domain (controls, mechanism, hydraulics, thermal etc.) in nature. This paper describes the process of the development of a Multi-domain simulation of a wheel-loader. Working hydraulics, kinematics of working tool, driveline, engine and cooling system are modelled in LMS Amesim. Contacts between boom/bucket and bucket/ground are defined to constrain the movement of the bucket and boom.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Vibrations at the cabin or at the implements of construction machinery represents important drawbacks from the points of view of machine productivity, safety and operator comfort. Oscillations of these machines are particularly relevant due to the absence of shock absorbers, typical of many machines such as wheel loaders, and their use in uneven ground conditions. Several hydraulic solutions have been proposed in the past to reduce oscillations at both the cabin or at the machine boom. Particularly, cabin oscillations can be attenuated by properly counteracting the exciting oscillatory forces from the tires with motion of the boom. Many state of the art machine utilize a passive methods to implement this strategy. The present work introduces a novel active solution, based on the control of the boom actuator without involving modifications of the standard hydraulic system.
2016-09-27
Technical Paper
2016-01-8122
Jiaqi Xu, Hwan-Sik Yoon, Jae Y. Lee, Seonggon Kim
A neural network-based computer vision system is developed to estimate position of an excavator manipulator in real time. A camera is used to capture images of a manipulator, and the images are used to train a neural network. Then, the trained neural network can estimate the position of the excavator manipulator in real-time. To study the feasibility of the proposed system, an excavator simulator with a webcam is used. The simulation results show that the developed neural network-based computer vision system can estimate the position of the excavator manipulator with an acceptable accuracy.
2016-09-27
Technical Paper
2016-01-8138
Pranav Shinde, Ravi K, Nandhini Nehru, Sushant Pawar, Balaji Balakrishnan, Vinit Nair
Body in white forms a major structure in any automobile. It is responsible in providing structural rigidity to vehicle, safety, frame and a skeleton to support all body parts of vehicle. When it comes to judge the performance of vehicle, BIW is analyzed not only for its strength and shape but also weight. Light weight BIW structures have seen to be developed rapidly in order to fulfill requirement of best vehicle performance in dynamic conditions. Since then lot of efforts have been put into CAE, materials research, advanced manufacturing process and joining methods, each plays a critical role in BIW functionality. Constructional designing, development of light materials with improved strength and special manufacturing practices for BIW are few research areas with never ending questions. This paper attempts to review various factors studied for weight reduction and solutions provided so far. Some of the major findings are briefly discussed and suggestions are made for future research.
2016-09-27
Technical Paper
2016-01-8152
Brian R. McAuliffe, David Chuang
In an effort to support Phase 2 of Greenhouse Gas Regulations for Heavy-Duty Vehicles in the United States, a track-based test program was jointly supported by Transport Canada, Environment and Climate Change Canada, the US Environmental Protection Agency, and the National Research Council Canada to verify aerodynamic evaluation methodologies proposed by the US EPA. Coast-down and Constant-Speed tests were conducted with a modern aerodynamic tractor matched to a conventional 53 ft dry-van trailer, and outfitted with two drag reduction technologies. Enhanced wind-measurement instrumentation was introduced, consisting of a vehicle-mounted fast-response pressure probe and four track-side sonic anemometers that, when used in combination, provided reliable measurements of the wind conditions experienced by the vehicle during the tests.
2016-09-27
Technical Paper
2016-01-8022
Petter Ekman, Roland Gardhagen, Torbjörn Virdung PhD, Matts Karlsson
Reducing energy consumption and emissions are ongoing challenges for the transport sector. The increased number of goods transports emphasize these challenges even more, as greenhouse gas emissions from these vehicles has increased by 20 % since 1990 in Sweden. One special case of goods transports is that of timber. Today in Sweden, around 2000 timber trucks transport around six billion ton kilometers every year. For every ton kilometer these vehicles use around 0.25 liter diesel, and there should exist large possibilities to reduce the fuel consumption and the emissions. These timber trucks spend most of their operation time travelling in speeds of around 80 km/h. At this speed aerodynamic drag contributes to around 30% of the total vehicle resistance, which makes the aerodynamic drag a significant part of the energy consumption. One of the big challenges with timber trucks is that they travel empty half of the time.
2016-09-27
Technical Paper
2016-01-8112
Jorge Leon, Andres Gonzalez, Jose M. Garcia, Mario J. Acero
Electric motors have energy efficiency and performance advantages over traditional internal combustion engines. Nevertheless, when used for transportation, they have limited ranges due to the state of current energy storage technologies. In order to improve efficiency and increase the range of operation of electric vehicles, complementary energy regeneration systems can be used. A hydraulic energy recovery system is proposed to be used as a regenerative system for supplementing energy storage. This system consists of a hydraulic accumulator, a low pressure reservoir and a hydraulic pump/motor. The pump/motor device transforms kinetic energy into hydraulic energy during breaking, to move the hydraulic fluid from the low pressure reservoir to the hydraulic accumulator. This energy can later can be used to propel the vehicle. The proposed system is particularly useful for vehicles in heavy start-stop traffic and public transportation.
2016-09-27
Technical Paper
2016-01-8139
Santosh Nalanagula, Varadharajan G T
Aerodynamic Drag Reduction for Commercial Trucks Aerodynamic drag contributes to 50-60% of fuel consumption in trucks on highways. The limits of conventional wind tunnel testing have forced researchers to study about the drag and ways of reducing it computationally. Due to the stricter norms and eco-friendly approaches, truck manufacturers have begun to invest more for developing truck aerodynamics. This paper evaluates a European vehicle on European conditions. Drag reduction are mostly made by geometric changes. Pressure drag, a major drag for trucks as they run at lower speeds is produced by the shape of the object. Making streamlined bodies as trucks are tougher since it can affect its purpose. Therefore, addition of some components can suffice the needs. The changes in geometry have been implied and analysis for these geometrical changes are done to analyze the better geometry which can provide drag reduction features.
2016-09-27
Technical Paper
2016-01-2095
Agata Suwala, Lucy Agyepong, Andrew Silcox
Reduction of overall drag to improve aircraft performance has always been one of the goals for aircraft manufacturers. One of the key contributors to decreasing drag is achieving laminar flow on a large proportion of the wing. Laminar flow requires parts to be manufactured and assembled within tighter tolerance bands than current build processes allow. Drilling of aircraft wings to the tolerances demanded by laminar flow requires machines with the stiffness and accuracy of a CNC machine while having the flexibility and envelope of an articulated arm. This paper describes the development and evaluation of high accuracy automated processes to enable the assembly of a one-off innovative laminar flow wing concept. This project is a continuation of a previously published SAE paper related to the development of advanced thermally stable and lightweight assembly fixture required to maintain laminar flow tolerances.
2016-09-27
Technical Paper
2016-01-2098
Christophe Vandaele, Didier Friot, Simon Marry, Etienne Gueydon
With more than 10 000 aircrafts in their order backlog, automated assembly is of critical importance to the progress for aircraft manufacturers. Moreover to obtain maximum benefit from automation, it is necessary to achieve not only an integrated fastener cell, but also a real breakthrough in fasteners technology. The optimum solution, known as "One Side Assembly", performs the whole assembly sequence from one side of the structure using an accurate robot arm equipped with a Multi function End effector and high performances fasteners. This configuration provides an efficient and flexible automated installation process, superior to current solutions which are typically, large scale, capital intensive, systems, which still require operators to complete or control the fastener installation. The search for a technological breakthrough in this domain has been targeted for more than 15 years by the majors aircrafts manufacturers.
2016-09-27
Technical Paper
2016-01-8070
Prasad vegendla, Tanju Sofu, Rohit Saha, Mahesh Madurai Kumar, Long-Kung Hwang, Steven Dowding
Fan and Fan-shroud design is critical for underhood air flow management. The objective of this work is to demonstrate a method to optimize fan-shroud shape in order to maximize cooling air mass flow rates through the heat exchangers using the Adjoint Solver in STAR-CCM+®. Such techniques using Computational Fluid Dynamics (CFD) analysis enables the automotive/transport industry to reduce the number of costly experiments that they perform. This work presents the use of CFD as a simulation tool to investigate and assess the various factors that can affect the vehicle thermal performance. In heavy-duty trucks, the cooling package includes heat exchangers, fan-shroud, and fan. In this work, the STAR-CCM+® solver was selected and a java macro built to run the primal flow and the adjoint solutions sequentially in an automated fashion.
2016-09-20
Technical Paper
2016-01-2026
Dhwanil Shukla, Nandeesh Hiremath, Narayanan Komerath
Rigid or semi-rigid airships are gaining appeal for several applications requiring steady cargo transport, long endurance, low downwash and noise over populated areas, and rescue missions. Modern rigid-hulled airships use auxiliary lift and propulsion for the load-carrying segments of their operations. Tilting ducted fans and quad-rotors have been typically considered for the purpose. We are developing a concept where cycloidal rotors are used. These can operate both as lifting devices and as propulsive devices. The size of an airship allows the cylcoidal rotor to have a much larger diameter than on a helicopter, so that the rotation speed is low, and while minimizing downwash and noise. These features make the cycloidal rotor/airship combination ideas for the hypercommuting-on-demand application over congested urban and suburban areas. In this paper, the literature on hypercommuting, airships and cycloidal rotors will be surveyed.
2016-09-20
Technical Paper
2016-01-2056
Nikolaus Thorell, Vaibhav Kumar, Narayanan Komerath
A combat aircraft in landing approach is likely to encounter wind turbulence, causing the flow over its swept wings to be yawed. This paper examines the effect of yaw on the spectra of turbulence above and aft of the wing, in the region where fins and control surfaces are located. Prior work has shown the occurrence of narrowband velocity fluctuations in this region for most combat aircraft models, including those with twin fins. Fin vibration and damage has been traced to excitation by such narrowband fluctuations. The issue in this paper is the effect of yaw on these fluctuations, as well as on the aerodynamic loads on a wing. A 42 degree delta wing with rounded leading edges, roughly equivalent to a 1/25 scale of existing combat aircraft, is used in a 2.74 m low speed wind tunnel in the angle of attack range 18 to 35 degrees and at significant yaw settings.
2016-09-20
Technical Paper
2016-01-2010
Nandeesh Hiremath, Dhwanil Shukla, Narayanan Komerath
The design of advanced rotorcraft hinges on knowledge of the flowfield and loads on the rotor blade at extreme advance ratios (ratios of the forward flight speed to rotor tip speed). In this domain, strong vortices form above and below the rotor, and their evolution has a sharp influence on the aerodynamics loads experienced by the rotor, particularly the loads experienced at pitch links. To capture the load distribution, the surface pressure distribution must be captured. This has posed a severe problem in wind tunnel experiments. A 2-bladed teetering rotor with collective and cyclic pitch controls is used in a 2.74m wind tunnel, under conditions of dynamic stall and then in reverse flow. Stereoscopic particle image velocimetry us used. Recently we have shown that the accuracy of stereoscopic particle image velocimetry has reached the point where velocity measurements can be converted to pressure both at and away from the blade surface.
2016-09-20
Technical Paper
2016-01-1979
William D. Bertelsen
Technology to create a VTOL for general aviation that is fast, efficient, easy to fly, and affordable, has proven elusive. Bertelsen Design LLC has built a large research model to investigate the potential of the arc wing VTOL to fulfill these attributes. The aircraft that is the subject of this paper weighs approximately 145 kg (320 lbs) and features coaxial, dual-rotating propellers, diameter 1.91 m (75 inches). Power is from an MZ-202 two-cycle, two-cylinder engine. Wingspan is 1.82 m (72 inches). The arc wing differentiates this aircraft from previous deflected-slipstream prototypes, which suffered from pitch-trim issues during transition. This paper will present configuration details of the Bertelsen model, showing how it is possible to generate high lift from a short-span wing system. The Bertelsen model can hover out of ground effect using just two arc-wing elements: a main wing and a “slat”.
2016-09-20
Technical Paper
2016-01-1989
Qiong Wang, Rolando Burgos, Xuning Zhang, Dushan Boroyevich, Adam White, Mustansir Kheraluwala
In modern aircraft power systems active power converters have been increasingly adopted to replace passive (diode-based) rectifiers seeking to increase the power-density and specific-weight of these units. These converters represent a significant challenge from a design standpoint due to the added degrees of freedom they offer, which have been further expanded by the adoption of wide-bandgap (WBG) power semiconductors. As such, their design requires the formulation of complex multi-disciplinary, multi-loop design procedures to ensure that they are built to fully exploit their power processing capabilities, while meeting the operational requirements of aircraft applications; including electromagnetic interference (EMI) standards, power quality standards, form factor and weight constraints, efficiency, and other relevant figures of merit.
2016-09-20
Technical Paper
2016-01-2059
Rolf Loewenherz, Virgilio Valdivia-Guerrero, Daniel Diaz Lopez, Joshua Parkin
Auto transformer rectifier units (ATRUs) are commonly used in aircraft applications such as electric actuation for harmonic mitigation due to its high reliability and relative low cost. However, those components and the magnetic filter components associated to it are major contributors to the overall size and weight of the system. Optimization of the magnetic components is essential in order to minimize weight and size, which are major market drivers in aerospace industry today. This requires knowledge of the harmonic content of the current. This can be obtained by simulation, but the process is slow. In order to enable fast and efficient design space exploration of optimal solutions, an algebraic calculation process is proposed in this paper for multi-pulse ATRUs (e.g. 12-pulse and 18-pulse rectifiers), starting from existing solution proposed for 6 pulse rectifier in the literature.
2016-09-20
Technical Paper
2016-01-1984
Michael Krenz
The cost of going from point A to point B is really all about how efficiently we convert stored energy into the motion desired to move us to the desired end point in a given amount of time and within the constraints of infrastructure. While it may be theoretically possible to use a rocket powered car to go from New York to Los Angeles, it is not practical to consider doing so given the available infrastructure. Several constraints will bound this discussion. First, the desired travel distance is approximately 4,000nm within 1 business day (~8 hours). Second, this distance may be either over land or water. Third, existing infrastructure is assumed without significant changes. And fourth, the individual cost of the trip shall not exceed 75% of the cost of a comparable trip today (that is, a 25% cost reduction is required). While mature (e.g.
2016-09-20
Technical Paper
2016-01-2024
Allan J. Volponi, Liang Tang
Engine module performance trending and engine system anomaly detection and identification is a core capability for any engine Condition Based Maintenance system. The genesis of on-condition monitoring can be traced back nearly 4 decades, and a methodology known as Gas Path Analysis (GPA) has played a pivotal role in its evolution. Gas Path Analysis is a general methodology that assesses and quantifies changes in the underlying performance of the major modules of the engine (compressors and turbines) which directly affect performance changes of interest such as fuel consumption, power availability, compressor surge margins, etc. It utilizes instrumentation such as spool speeds, inter-stage temperatures and pressures and power output, much of which is already available on the propulsion system for control purposes.
2016-09-20
Technical Paper
2016-01-2025
Amir Fazeli, Adnan Cepic, Susanne Reber
Aircraft weight and center of mass are two critical design and operational parameters that have to be within a design envelope to ensure a safe and efficient operation of aircraft. Previous efforts to accurately determine aircraft weight and center of mass before takeoff using landing gear shock strut pressures have failed due to the distortion of measured pressures by shock strut seal friction. Currently, aircraft loading process is controlled with loading sheets and passenger/cargo weight estimation as there are no online measurement systems that can accurately and efficiently estimate aircraft weight and determine the center of mass location before takeoff. However, errors in loading sheets, shifting cargo and errors in weight estimation could lead to incorrect loading of aircraft and, consequently, increase the risk of accidents, particularly in cargo flights.
2016-09-20
Technical Paper
2016-01-2034
Tobias Kreitz, Frank Thielecke
The aviation industry is facing major challenges due to increased environmental requirements that are driven by economic constraints. For this reason, guidelines like "Flightpath 2050", the official guide of European aviation, call for significant reductions in pollutant emissions. The concept of the "More Electric Aircraft" offers promising perspectives to meet these demands. A key-enabler for this concept is the integration of new technologies on board of the next generation of civil transportation aircraft. Examples are electro-mechanical actuators for primary flight controls or the fuel cell technology as innovative electrical energy supply system. Due to the high complexity and interdisciplinary, the development of such systems is an equally challenging and time-consuming process. To support the classical development process, a continuous model-based approach for the design and test of complex aircraft systems is currently developed at the Hamburg University of Technology.
Viewing 1 to 30 of 19192