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Event
2015-06-22
This session includes papers regarding vehicle exterior or interior tire/pavement noise.
Training / Education
2015-06-16
One of the most important safety critical components on cars, trucks, and aircraft is the pneumatic tire. Vehicle tires primarily control stopping distances on wet and dry roads or runways and strongly influence over-steer/under-steer behavior in handling maneuvers of cars and trucks. The inflated tire-wheel assembly also acts as a pressure vessel that releases a large amount of energy when catastrophically deflated. The tire can also serve as a fulcrum, both directly and indirectly, in contributing to vehicle rollover. This seminar covers these facets of tire safety phenomena. Engineering fundamentals are discussed and illustrated with numerous practical examples and case studies of current public interest.
Training / Education
2015-06-15
The principal functions of the pneumatic tire are to generate driving, braking, and cornering forces while safely carrying the vehicle load and providing adequate levels of ride comfort. This seminar explains how tire forces and moments are generated under different operating and service conditions and, in turn, demonstrates how these forces and moments influence various vehicle responses such as braking, handling, ride, and high-speed performance. The content focuses on the fundamentals of tire behavior in automobiles, trucks, and farm tractors, but also includes experimental and empirical results, when necessary.
Training / Education
2014-11-03
                                                                 Understanding vehicle dynamics is one of the critical issues in the design of all vehicles, including heavy trucks. This seminar provides a comprehensive introduction to the fundamentals of heavy truck dynamics. It covers all of the critical subsystems that must be considered by designers and decision makers in determining the effect of various components on heavy truck dynamics. This seminar begins where the tires meet the ground, progressing up through the various components and bringing together the theory and practice of heavy truck dynamics.
Event
2014-10-07
This technical session invites papers on dynamics and performance of conventional and unmanned, on-road/off-road vehicles with emphasis on dynamics and design of chassis, suspension, tires, and tracks. In the area of vehicle chassis with four and more number of driving wheels, papers are welcome, but not limited to: various types of suspensions and their interaction with the driving gear, steering, and driveline systems. Research papers presenting results on analysis, optimization, and control of tire dynamics and design for road and terrain vehicle applications are encouraged to be submitted to this session. Special attention is also given to rubber-track chassis systems and their asphalt passability and terrain mobility. Papers on conventional track system dynamics, design, and reliability issues are also invited. Energy efficiency issues, stochastic modeling, smoothness of ride, integrated design of chassis subsystems are also considered.
Event
2014-10-07
Technical Paper
2014-09-30
Boris Belousov, Tatiana I. Ksenevich, Vladimir Vantsevich, Sergei Naumov
An open-link locomotion module (OLLM) is considered as autonomous energy self-sufficient locomotion setup for designing ground wheeled vehicles of a given configuration including the number of the drive/driven and steered/non-steered wheels with individual suspension and brake systems. The paper concentrates on the module’s electro-hydraulic suspension design and presents results of analytical and experimental studies. The suspension design provides the sprung mass with sufficient vibration protection at low level of normal oscillations, enhanced damping and stabilized angular movements on highly non-even terrain. This is achieved by the introduction of two control loops: (i) a fast-acting loop to control the damping of the normal displacements; and (ii) a slow-acting control loop for varying the pressure and counter-pressure in the suspension system. Thus, two separate but coordinated controls were designed for both loops to act under small (less than ±7 degrees) and big (larger than ±7 degrees) pitch and roll angles of a vehicle designed with a set of the modules.
Technical Paper
2014-09-30
Guoying Chen, Dong Zhang
Four-wheel independent control electric vehicle is a new type of x-by-wire vehicle with four wheels independent steering and four wheels independent drive/brake systems. Due to the superiority of its structure, the vehicle can perform some special actions that conventional vehicles couldn’t complete, such as zero radius turning, oblique driving and crab. These greatly improve the mobility of four-wheel independent control electric vehicles under low speed condition. Furthermore, the vehicle could get better handing stability by the integrated chassis control for steering and drive/braking systems. So in the paper we try to study the integrated chassis control on how to optimally distribute the angles/torque of each wheel of four-wheel independent control electric vehicle that maximizes the used of the friction between tire and road. In order to introduce the vehicle integrated chassis control clearly, this paper is divided into four parts. In part one, the control targets and the hierarchical control structure of the integrated chassis controller are described.
Technical Paper
2014-09-30
Dong Zhang, Changfu Zong, Guoying Chen, Pan Song, Zexing Zhang
This paper mainly focuses on the dynamic characteristics and control methods for drive-by-wire electric vehicle. In this paper, the system architecture of the full drive-by-wire electric vehicle is proposed, which vehicle control unit is based on a rapid control prototyping. The X-by-wire electric vehicle is developed with four wheels independently steered, driven by in-wheel motors, braked by electromagnetic brakes and controlled by active suspensions. To identify and classify the drivers’ characteristics, the MDHMM is established by utilizing HMM and Baum-Welch algorithms. A double layer HMM is used to conduct onboard identification according to the driver’s inputs, environmental information and vehicle states. And real-time ideal reference models of vehicle dynamics for different characteristic drivers are built up with RBF neural network technique by using the driving simulator test data, which use dynamics control for the electric vehicle. For a full drive-by-wire electric vehicle, the wheel speed and braking torques of each wheel can be readily obtained.
Technical Paper
2014-09-30
Anudeep K. Bhoopalam, Corina Sandu, Saied Taheri
Safety and minimal transit time are vital during transportation of essential commodities and passengers, especially during winter conditions. Icy roads are the worst driving conditions with the least available friction leaving valuable cargo and precious human lives at stake. This study investigates the available friction at the tire-ice interface due to changes in key operational parameters. Experimental analysis of tractive performance of tires on ice was carried out indoor, using the terramechanics rig located at the Advanced Vehicle Dynamics Laboratory (AVDL) at Virginia Tech. The friction-slip ratio curves were also generated from model simulations and compared to the experimental findings from the terramechanics rig. The shortcomings of simulations in considering all the effects of all the operational parameters result in a difference in the friction values obtained by the two methods. Thus, arises the need for state-of-the-art tire-ice models capable of predicting accurate friction levels taking into account all operational conditions.
Standard
2014-08-11
The J1939 Digital Annex The J1939 Digital Annex, introduced in August 2013, offers key J1939 technical data in an Electronic Spreadsheet that can be easily searched, sorted, and adapted to other formats. J1939DA contains all of the SPNs (parameters), PGNs (messages), and other J1939 data previously published in the SAE J1939 top level document. J1939DA also contains all of the SLOTs, Manufacturer ID Codes, NAME Functions, and Preferred Addresses previously published in the SAE J1939 top level and the J1939-71 document. J1939DA contains the complete technical details for all of the SPNs and PGNs previously published in the SAE J1939-71 document. For all other SPNs and PGNs which are published in a document other than SAE J1939-71, J1939DA lists only basic details along with a reference to the document that contains the complete technical details. J1939DA replaces, and expands upon, the 1939 Companion Spreadsheet (CS1939), which was last published through November 2012. The data fields included in J1939DA for PGNs are: PGN Parameter Group Label Acronyn EDP DP PF PGN Length PS PGN Description Multipacket Transmission Rate PGN Data Length Default Priority PGN Reference PGN Document The data fields included in J1939DA for SPNs are: SPN SPN Name SPN Description SPN Length Resolution Offset Data Range Operational Range Units SLOT Identifier SPN Type SPN Reference SPN Document The J1939 Digital Annex is current through Second Quarter 2014 and can be purchased separately or as part of the SAE J1939 Standards Collection on the Web.
Standard
2014-07-30
This recommended practice contains dimensions and tolerances for spindles in the interface area. Interfacing components include axle spindle, bearing cones, bearing spacer, seal and wheel hub. This recommended practice is intended for axles commonly used on Class 7 and 8 commercial vehicles. Included are SAE axle configurations FF, FL, I80, L, N, P, R, U, and W.
Standard
2014-07-29
This SAE Aerospace Information Report (AIR) describes the design approaches used for current applications of aircraft Brake-by-Wire (BBW) control systems. The document also discusses the experience gained during service, and covers system, ergonomic, hardware, and development aspects. The document includes the lessons that have been learned during application of the technology. Although there are a variety of approaches that have been used in the design of BBW systems, the main focus of this document is on the current state of the art systems.
Standard
2014-07-11
This specification covers minimum design and test requirements for aircraft tire inflation-deflation equipment for use on all types of aircraft. It shall be the responsibility of the airframe manufacturer to determine the compatibility of the requirement with the applicable aircraft and to specify requirements in excess of these minimums as necessary.
Technical Paper
2014-06-30
Gregor Koners, Ralf Lehmann
Abstract Low interior noise levels in combination with a comfortable sound is an important task for passenger cars. Due to the reduction of many noise sources over the last decades, nowadays tire-road noise has become one of the dominant sources for the interior noise. Especially for manufactures of luxury cars, the reduction of tire-road noise is a big challenge and therefore a central part of NVH development. The knowledge of the noise transmission behavior based on the characteristics of the relevant sources is a fundamental of a modern NVH - development process. For tire-road noise the source characteristics can be described by wheel forces and radiated airborne noise. In combination with the related vehicle transfer functions it is possible to describe the noise transmission behavior in detail. A method for estimating wheel forces and radiated airborne noise is presented. The method is based on TPA (= Transfer Path Analysis) via matrix inversion and involves the measurement of the vehicle transfer functions.
Standard
2014-06-16
This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the installation, inflation, inspection, and maintenance of aircraft tires as well as criteria for the maintenance of the operating environment so as to achieve the purpose stated in 1.1. (Definitions of terms related to aircraft tires are found in 2.2.)
Standard
2014-06-16
This SAE Recommended Practice describes the basic content requirements, bar-code specifications, and functional test specifications of a vehicle emission configuration (VEC) label. On the vehicle, the VEC label is to be mounted under the hood in a readily accessible location for use of a bar-code scanning device. This document specifies a permanent vehicle emission configuration label that can be automatically identified through a bar-coded format.
Standard
2014-06-10
This SAE Aerospace Information Report (AIR) provides guidelines for the development of landing gear fatigue spectra for the purpose of designing and certification testing of Part 25 landing gear. Many of the recommendations herein are generalizations based on data obtained from a wide range of landing gears. The aircraft manufacturer or the landing gear supplier is encouraged to use data more specific to their particular undercarriage whenever possible.
Standard
2014-06-06
This SAE Recommended Practice describes a test method for determination of heavy truck (Class VI, VII, and VIII) tire force and moment properties under straight-line braking conditions. The properties are acquired as functions of normal force and slip ratio using a sequence specified in this practice. At each normal force increment, the slip ratio is continually changed by application of a braking torque ramp. The data are suitable for use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control.
WIP Standard
2014-06-02
This SAE Recommended Practice outlines the qualification testing and performance related criteria of elastomeric boot seals used in constant velocity joint applications. These applications are referred to as front- wheel-drive halfshafts or axles, but can also be utilized in rear-wheel-drive halfshaft applications. For additional information regarding CV joint systems and their applications refer to SAE AE-7 "Universal Joint and Driveshaft Design Manual." The grease type and grease quantities, clamps and clamping mechanisms of an assembly are critical and considered to be the same as OEM, service, or aftermarket designation. Although joint lubricating grease and clamping mechanism are not addressed in this document, they are critical to a total system performance. The purpose of this document is to establish a uniform practice for those in the surface vehicle industry that specify and/or manufacture CV joint boot seals (boots) for OEM or aftermarket use with respect to qualification testing for physical and mechanical properties.
Event
2014-05-16
Standard
2014-05-16
This SAE Recommended Practice establishes a rating scale for subjective evaluations of noise and discomfort in motor vehicles. Through test procedures utilizing specific vehicles on specific roads, the scale may be utilized to assess the relative contributions of tires to noise and discomfort. The noise and ride comfort characteristics attributed to automotive tires have traditionally been estimated by subjectively assigning number designations (commonly on a 1 to 10 scale) to the audible and tactile sensations observed while traversing a given road course in a vehicle equipped with the tires under evaluation. Regardless of advances in objective measurements of tire properties related to noise and discomfort, subjective evaluation will continue to be necessary for the purpose of establishing the significance of such measurements. The rating scale of this recommendation is applicable to assessment of each of the wide variety of audible and tactile disturbances referred to by such terms as bump, thump, slap, shake, etc.
Standard
2014-05-16
This procedure provides for the measurement of the sound generated by a test tire, mounted on a single-axle trailer, operated at multiple speeds. The procedure describes test practices for both United States and International practices. Specifications for the instrumentation, the test site, and the operation of the test apparatus are set forth to minimize the effects of extraneous sound sources and to define the basis of reported sound levels.
Technical Paper
2014-05-10
Hyeonu Heo, Jaehyung Ju, Doo Man Kim, Harkbong Kim
An understanding of the flow around a tire in contact with the ground is important when designing fuel-efficient tires as the aerodynamic drag accounts for about one third of an entire vehicle's rolling loss. Recently, non-pneumatic tires (NPTs) have drawn attention mainly due to their low rolling resistance associated with the use of low viscoelastic materials in their construction. However, an NPT's fuel efficiency should be re-evaluated in terms of aerodynamic drag: discrete flexible spokes in an NPT may cause more aerodynamic drag, resulting in greater rolling resistance. In this study, the aerodynamic flow around a non-pneumatic tire in contact with the ground is investigated for i) stationary and ii) rotating cases using the steady state Reynolds-Averaged Navier-Stokes (RANS) method. A sensitivity analysis was carried out with a varying mesh density. The flow into cavity by the discrete spoke geometry of the NPT does not significantly affect the overall aerodynamic drag.
Viewing 1 to 30 of 2748

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