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Viewing 1 to 30 of 2302
Event
2015-06-22
This session includes papers in the areas of static, dynamic, and fatigue characterization of elastomers, bushings, mounts and shock absorbers used in the mobility industry. Particular emphasis is given to new and innovative analysis and testing methodologies to quantify the non-linear properties of these systems in addition to the effects of temperature, frequency, and aging. Papers dealing with specific applications and case studies of existing methodologies are also welcome.
Training / Education
2014-11-17
While a variety of new engineering tools are becoming available to assist in creating optimal vehicle designs, subjective evaluation of vehicle behavior is still a vital tool to ensure desired braking, handling, and other dynamic response characteristics. In order to better prepare today's engineer for this task, this course offers twelve modules devoted to the key fundamental principles associated with longitudinal and lateral vehicle dynamics. Each focused classroom session is paired with an on-track exercise to immediately reinforce these concepts with a dedicated behind-the-wheel driving session, effectively illustrating these principles in the real world.
Training / Education
2014-11-12
Just as the chassis and suspension system provides an ideal framework for the automobile, this popular SAE seminar provides an informative framework for those involved in the design of these important systems. Emphasizing the fundamental principles that underlie rational development and design of suspension components and structures, this course covers the concepts, theories, designs and applications of automotive suspension systems.
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.
Training / Education
2014-10-20
This seminar will present an introduction to Vehicle Dynamics from a vehicle system perspective. The theory and applications are associated with the interaction and performance balance between the powertrain, brakes, steering, suspensions and wheel and tire vehicle subsystems. The role that vehicle dynamics can and should play in effective automotive chassis development and the information and technology flow from vehicle system to subsystem to piece-part is integrated into the presentation. Governing equations of motion are developed and solved for both steady and transient conditions. Manual and computer techniques for analysis and evaluation are presented.
Event
2014-10-09
This session focuses on theoretical and experimental vehicle dynamics aspects of both on- and off-road vehicles. Papers on topics such as off-road vehicle chassis and suspension, NVH, driver/operator comfort, as well as on-road suspension design, active and semi-active suspension systems and controls, and full vehicle dynamic studies are welcomed. Topics ranging from on-road vehicles to trucks to construction and mining machinery are covered in CV205.
Event
2014-10-07
Active Safety Systems are becoming commonplace on commercial vehicle systems. These systems can include but are not limited to safety systems that assist to mitigate or in some cases, avoid accidents by intervening through visual/audible warnings, providing steering assist or active braking to slow the vehicle down. The size and complexity of the commercial vehicles offers some challenges to the application of these systems. This panel session will bring together experts in the area to discuss the recent developments and challenges going forward in the application of Anti-lock braking systems, Traction control systems, Electronic Stability Control systems, Lane Keeping Systems, Adaptive Cruise Control, Autonomous Emergency Braking system for commercial vehicles.
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.
Technical Paper
2014-09-30
Iman Hazrati Ashtiani, Mehrnoosh Abedi
Road trains have been applied as one of the efficient ways for transportation of goods in different countries like United States, Canada, Brazil and Australia. These long vehicles have a wide variety in length or towing systems like fifth wheel or dolly draw-bar and based on specific measured and regulation could be authorized to move in specific roads. In order to avoid hazard and danger in case of accidents of these vehicles, safety performance of a specific type of these vehicles, called B-train, is investigated in this paper. A Multi-Body Dynamics (MBD) model of a B-train, which consists of a prime mover and two trailers coupled by fifth wheels, are simulated in first phase of study. The developed dynamic model is capable of simulating required tests as well as SAE lane change and constant radius turn for roll and yaw stability analysis and safety evaluation. As far as transportation of fuel or other hazardous liquid are a common usage of B-train vehicles, the effects of liquid fill level variation are also considered in this research.
Technical Paper
2014-09-30
Xianjian Jin, Guodong Yin, Youyu Lin
Knowledge of vehicle dynamics variables is very important for vehicle control systems that aim to improve handling characteristics and passenger safety. However for both technical and economical reasons some fundamental data (e.g., Lateral tire-road forces and vehicle sideslip angle) are not measurable in a standard car. This paper proposes a novel Interacting Multiple Model Filter-Based method to estimate lateral tire-road forces by utilizing real-time measurements. The method uses measurements (yaw rate, roll rate, accelerations, steering angle and wheel speed) only from sensors which have already been integrated in modern cars. The estimation method of lateral tire-road forces is based on an interacting multiple model (IMM) filter that integrates in-vehicle sensors of in-wheel-motor-driven electric vehicles to adapt multiple vehicle-road system models to variable driving conditions. Considering extended roll dynamics and load transfer, a four-wheel nonlinear vehicle dynamics model (NVDM) is built.
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.
Technical Paper
2014-09-30
Yiting Kang, Subhash Rakheja, Wenming Zhang
Different types of axle suspension systems have evolved for large size mining trucks to achieve improved attenuation of terrain-induced whole-body vibration (WBV) transmitted to the operator and to attain higher operating speeds. The hydro-pneumatic struts are increasingly being used together with different linkage configurations, which could yield widely different kinematic and dynamic properties and thereby the ride and handling performance of the vehicle. This paper presents comprehensive analyses of the different independent front suspension linkages that have been implemented in various off-road vehicles, namely a composite linkage Macpherson strut type suspension (CLT), a candle type suspension (CT), a longitudinal arm type suspension (LAT), and a double wishbone type suspension (DWT). The relative performance analyses are evaluated on the basis of handling dynamics of a 190 tons mining truck. The kinematic variations in camber, caster, inclination angle, toe-in and horizontal wheel center displacements of different linkage suspensions are synthesized via wheel bounce excitations in the MapleSim platform.
Technical Paper
2014-09-30
Vladimir V. Vantsevich, Jeremy P. Gray, Dennis Murphy
Through inverse dynamics-based modeling and computer simulations for a 6x6 unmanned ground vehicle in stochastic terrain conditions, this paper analytically presents a coupled impact of different driveline system configurations and a suspension design on vehicle dynamics, including vehicle mobility and energy efficiency. A new approach in this research work involves an estimation of each axle contribution to the level of potential mobility loss/increase and/or energy consumption increase/reduction. As it is shown, the drive axles of the vehicle interfere with the vehicle’s dynamics through the distribution of the wheel’s normal reactions and wheel torques. The interference causes the dynamics of the independent systems to become operationally coupled/fused, and thus diminishes the vehicle’s mobility and energy efficiency. The analysis is achieved by the use on new mobility indices and energy efficiency indices which are functionally coupled/fused. Four possible scenarios are considered to trade between mobility and energy efficiency improvements by re-distributing power between the drive axles in severe/extreme terrain conditions, including poor mu-conditions, and high longitudinal and lateral slopes.
WIP Standard
2014-07-21
No scope available.
Technical Paper
2014-06-30
Hiromichi Tsuji, Satoshi Takabayashi, Eiji Takahashi, Hitoshi Murakami, Shinichi Maruyama
A finite element (FE) model of vibro-acoustic coupling analysis, such as a vehicle noise and vibration, is utilized for the improvement of the performance in the vehicle development phase. However, the accuracy of the analysis is not enough for substituting a prototype phase with a digital phase in the product development phases. Therefore, conducting the experiments with the prototype vehicle or the existed production vehicle is still very important for the performance evaluation and the model validation. The vehicle noise transfer function of the road noise performance cannot be evaluated with the existed excitation equipment, such as the 3 or 6 directional electromagnetic shaker. Therefore, this paper proposes new experimental method to measure the road noise vehicle transfer function. This method is based on the reciprocity between the tire contact patch and the driver's ear location. The reaction force sensor of the tire contact patch is newly developed for the reciprocal loud speaker excitation at the passenger ear location.
WIP Standard
2014-06-16
This recommended practice is a source of information for body and trim engineers and represents existing technology in the field of on-highway vehicle seating systems. It provides a more uniform system of nomenclature, definitions of functional requirements, and testing methods of various material components of motor vehicle seating systems.
Magazine
2014-06-03
Systems-engineering a new 4x4 benchmark Chrysler Powertrain teamed with AAM to create the industry's most capable, sophisticated-and arguably most fuel-efficient-AWD/4WD driveline. Top engineers talk about their collaboration. Achates aims at 2025 light-truck power After more than a decade of steady development, Achates Power's opposed-piston two-stroke diesel is impressing powertrain experts with its test results and pace of technical progress. Lighter, stronger chassis Development of a new high-strength aluminum casting alloy for the production of suspension components.
Technical Paper
2014-05-07
Eraldo de Jesus Soares, Alan M. Oliva, Camilo A. Adas, Fernando C. Dusi, Paulo Sergio P. Santos, Marco A. Fogaça Accurso, Marcus Kliewer
Abstract The purpose of this paper is to show a multiaxial bench test for static and dynamic testing of leaf springs for suspension of commercial vehicles. The bench test simulates the critical operating conditions (track, ramp, speed bump on track, curves and braking), with stroke control for strength and deformation analysis. One of the main advantages in bench test is to reduce the time of the test, its repeatability, its cost saving and monitoring its performance through inspections and graphic records. The aim of the test is to evaluate the behavior in durability of the components, to analyze the possible failure mode and to be able to approve or reject the component based on the test's results. Criteria were set to accelerate the test by comparing signals measured on the field and bench test with deflection by stress curves. These criteria were maintained under extreme conditions for longer than the observed in previous and real applications. With this, the low incidence of strength and stroke is measured by optimizing the time of the test.
Technical Paper
2014-05-07
Marcos dos Santos, Ricardo Guedes Manini, Jayme B. Curi, Cleber Chiqueti
Abstract ”U” bolts are fixing elements and they are used to clamp an elastic joint. From the past, they still looking as an old design and unfortunately, suspension engineers are not specialists in fasteners and elastic joints. That is why we will show important assumptions and concepts to design and specifications this clamp element “U” bolt and its influence over leaf-springs. Currently, “U” bolt is used to clamp an elastic or elastic-plastic joint of heavy duty suspension, formed by leaf-spring, axle, spring pad, “U” bolt plate. This kind of suspension is typically used to trucks, buses and trailers. We are wondering, which one important assumption that an engineer must be careful when designs a new suspension changing from old designs to an updated technology. We provide a theoretical analysis and a FEA analysis to compare torque efficacy x leaf-spring reactions and what are effects this relationship can cause in a suspension. To have a shortest development time and provide back an expected result from the suspension system, engineers should to consider more and new assumptions, evaluate virtual and practical performance of leaf-springs with “U” bolt designed to clamp all elastic joint and even the correct torque specification to the “U” bolt.
Technical Paper
2014-05-07
Claudio Gomes Fernandes, Eric Noguchi, Rômulo Castro, Uilian Almeida
Abstract Automotive industry has shown, in the recent years, a dramatically increase of competition at emergent markets. The incoming of new Brands, for example in the Brazilian market, is causing the OEMs to decrease costs while increase quality, which represents a big challenge nowadays. In this challenging scenario, virtual simulation has become mandatory. While cutting costs since no physical prototypes are required, virtual models also reduces development time. Time to time, as computers processing capacity grows, virtual models are becoming more and more accurate, being able to capture even high non-linear phenomena, which ten years ago would not be feasible. It is also known the natural tendency of vehicle dynamics engineers to develop shock absorber tuning only by means of subjective evaluation. Many reasons can be raised to this tendency, but one of them is the lack of representation of the entire shock absorber behavior in the virtual models. In this sense, the present work shows an attempt to capture the main non-linearities of shock absorbers that affect the most the vehicle behavior in terms of ride and handling.
Technical Paper
2014-05-07
Alfred Memmel, Anibal Berberich
Abstract Variable Damping systems for commercial vehicle applications have been in the market for several years now. The systems modify damping according to the actual demand within milliseconds. This reduces vertical accelerations which lead to improved comfort while maintaining vehicle stability and safety at the same time. Driver, cargo and vehicle are better protected. The technical effort for variable damping systems was in the past rather high and affected a limited market penetration. On the other side the used control algorithms did not tap the full potential of the system performance. New concepts, like integration of sensors or concentration on the most relevant axle, in combination with new control algorithms, simplifies the systems architecture and improves the performance. Besides the functional advantages, the system improves vehicle efficiency as it reduces the energy dissipated by the dampers. This energy would have to be generated by the engine. Less damping also relates to reduction of fuel consumption.
Technical Paper
2014-05-07
Saulo Machado Rodrigues, André Soares, Henrique Zambon, Odair Berti, Rudimar Mazzochi
During the field tests of a prototype of a cabin suspension assembly applied in a commercial vehicle it has been evidenced the premature failure in the torsion bar. Due to this failure, which happened with 20% of approval total test, one verified that the adding of a lateral displacement control bar (Panhard), attached to the torsion bar, promoted a significant additional force to it, which was not predicted in the initial dimensioning. Due to that, it was executed a re-design of the assembly, paying a special attention to the torsion bar, considering the influence of Panhard bar. To do that, several numerical simulations were carried out, using the finite element software Abaqus, whose boundary conditions were determined based on data collected in the field tests. Lately, the new concepts developed were submitted to bench tests, applying hydraulic actuators to apply the loads, in which one executed an experimental verification of stresses to calibrate the numerical models.
Technical Paper
2014-05-07
Frederico A. A. Barbieri, Vinicius de Almeida Lima, Leandro Garbin, Joel Boaretto
Abstract Brazil presents a very diverse road and traffic conditions and due to several factors the number of truck accidents is very high. Inside truck accidents group, the one that causes the highest number of losses and fatalities is the rollover crash and understanding rollover dynamics is very important to prevent such events. The diversity of cargo vehicles arrangements requires a detailed study regarding the dynamic behavior these vehicle combinations in order to increase operation safety. The same tractor unit can be used with different types and numbers of trailers and/or semi-trailers, each one with different suspension configurations. These truck combinations have distinct dynamic performances that need evaluation. In this sense, this work presents a first phase study on the dynamic behavior of different types of cargo vehicle configuration. A 6×2 tractor is combined with a two distinct grain semi-trailer with different types of suspension: pneumatic and leaf spring. The study is conducted in order to verify the difference in dynamic behavior and the resulting stability of the two configurations in different conditions of speed and maneuvers.
Technical Paper
2014-05-07
Fabio Augusto Schuh, Leandro Luís Corso, Leonardo Hoss
Abstract Applying knowledge available at technical literature for cycle counting, damage caused by each load cycle through S-N curve, and fatigue damage accumulation by Palmgren-Miner rule, durability prediction is performed for a leafspring of a commercial vehicle with 6×4 suspension system. Max principal tension is measured by means of strain gages in the most representative points for fatigue life of the leafspring, determined with FEA, while vehicle runs over off-road track in a proving ground. Load and tension are also measured in a laboratory bench test for this component. Correlation between off-road track and bench test is then performed. Finally, representative samples of the component are tested with dynamic loading until fatigue fracture in bench test, and using data from these tests, statistical analysis is performed with application of Weibull distribution, allowing life prediction in statistical terms.
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