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Viewing 1 to 30 of 2329
2011-04-12
Technical Paper
2011-01-0269
Adam Bryant, Joseph Beno, Damon Weeks
Battlefield reconnaissance is an integral part of today's integrated battlefield management system. Current reconnaissance technology typically requires land based vehicle systems to observe while stationary or, at best, significantly limits travel speeds while collecting data. By combining current Canadian Light Armored Vehicle based reconnaissance systems with the Center for Electromechanics (CEM) electronically controlled active Electromechanical Suspension System (EMS), opportunities exist to substantially increase cross-country speeds at which useful reconnaissance data may be collected. This report documents a study performed by The University of Texas Center for Electromechanics with funding from L3-ES to use existing modeling and simulation tools to explore potential benefits provided by EMS for reconnaissance on the move.
2011-04-12
Technical Paper
2011-01-0266
J.Y. Wong
With growing globalization of the economy, to gain a competitive edge in world markets shortening the product development cycle is crucial. Virtual product development is, therefore, being actively pursued in the off-road vehicle industry. To implement this process successfully, the development of comprehensive and realistic computer-aided methods for performance and design evaluation of off-road vehicles is of vital importance. To be useful to the engineer in industry for the development and design of new products, the computer-aided methods should take into account all major vehicle design parameters and pertinent terrain characteristics. They should be based on the understanding of the physical nature and the mechanics of vehicle-terrain interaction. Their capabilities should be substantiated by test data.
2011-04-12
Journal Article
2011-01-0437
Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.
2011-04-12
Journal Article
2011-01-0183
Brad Hopkins, Saied Taheri
Models for off-road vehicles, such as farm equipment and military vehicles, require an off-road tire model in order to properly understand their dynamic behavior on off-road driving surfaces. Extensive literature can be found for on-road tire modeling, but not much can be found for off-road tire modeling. This paper presents an off-road tire model that was developed for use in vehicle handling studies. An on-road, dry asphalt tire model was first developed by performing rolling road force and moment testing. Off-road testing was then performed on dirt and gravel driving surfaces to develop scaling factors that explain how the lateral force behavior of the tire will scale from an on-road to an off-road situation. The tire models were used in vehicle simulation software to simulate vehicle behavior on various driving surfaces. The simulated vehicle response was compared to actual maximum speed before sliding vs. turning radius data for the studied vehicle to assess the tire model.
2011-04-12
Technical Paper
2011-01-0191
Edoardo Sabbioni, Silvia Negrini, Francesco Braghin, Stefano Melzi lng
The paper investigates the interaction between soil and tractor tires through a 2D numerical model. The tire is schematized as a rigid ring presenting a series of rigid tread bars on the external circumference. The outer profile of the tire is divided into a series of elements, each one able to exchange a normal and a tangential contact force with the ground. A 2D soil model was developed to compute the forces at the ground-tire interface: the normal force is determined on the basis of the compression of the soil generated by the sinking of the tire. The soil is modeled through a layer of springs characterized by two different stiffness for the loading (lower stiffness) and unloading (higher stiffness) condition. This scheme allows to introduce a memory effect on the soil which results stiffer and keeps a residual sinking after the passage of the tire. The normal contact force determines the maximum value of tangential force provided before the soil fails.
2011-04-12
Technical Paper
2011-01-0090
Wei Liu, Wenku Shi Sr
In this paper, a Magneto-Rheological (MR) fluid semi-active suspension system was tested on a commercial vehicle, a domestic light bus, to determine the performance improvements compared to passive suspensions. MR fluid is a material that responds to an applied magnetic field with a significant change in its rheological behavior. When the magnetic field is applied, the properties of such a fluid can change from a free-flowing, low viscosity fluid to a near solid, and this change in properties takes place in a few milliseconds and is fully reversible. A quarter suspension test rig was built out to test the nonlinear performance of MR damper. Based on a large number of experimental data, a phenomenological model of MR damper based on the Bouc-Wen hysteresis model was adopted to predict both the force-displacement behavior and the complex nonlinear force-velocity response.
2013-04-08
Technical Paper
2013-01-1343
Marco Mammetti, David Gallegos, Alex Freixas, Jordi Muñoz
The focus of the work is to carry out a study of the relative impact of the rolling resistance measurements on CO₂ emission and fuel consumption reduction for heavy-duty vehicles. For the purpose of the study, friction coefficients of the tires from tire test machine according to UN/ECE Regulation No 117 test procedure have been used. The rolling resistance coefficient has also been obtained from SAE J1263 and SAE J2263 procedure for coast-down determination on proving ground. The fuel consumption has been simulated and tested on the proving ground by following FIGE standard cycle and stabilized speed conditions. A simulation tool has been developed and validated by testing different rolling resistance coefficient tires, analyzing their effect on the fuel consumption. The analysis of the contribution of the tires to fuel consumption achieved on the test track has been correlated with the experimental results and those obtained from the simulation tool.
2013-09-24
Technical Paper
2013-01-2396
Mohamed H. Zaher, Sabri Cetinkunt
This paper focuses on embedded control of a hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. A rule based control algorithm is developed and is tuned for different work cycles and might be linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the work-machine and its position via GPS, and maps both of them to the gains.
2013-09-24
Technical Paper
2013-01-2392
Daniel Blower, John Woodrooffe
Heavy truck rollover remains a primary factor in truck driver fatalities and injury. Roll stability control (RSC) and electronic stability control (ESC) are technologies that have been introduced to reduce the incidence of rollover in heavy truck crashes. This report provides an analysis of the real-world experience of a large for-hire company that introduced RSC into its fleet starting in 2004. The carrier provided a well-documented set of data on the operations of its truck-tractors, including both those equipped with RSC and those that did not have RSC installed. The purpose of the analysis is to determine the effect of RSC on the probability of rollover, as well as to identify other factors that either contribute to rollover or help reduce its incidence. This study presents results on the incidence of rollover both in terms of rollovers per 100 million miles traveled and the percentage of crashes that resulted in rollover.
2013-09-24
Technical Paper
2013-01-2382
Venkatesh Narayanan, Karalmarx R, Sai Sankaranarayana, Kalyankumar Hatti
The Bogie suspensions ensure better stability at higher loads and also give the utmost reliability under extreme climatic conditions with minimum maintenance. Many vehicle manufactures have adopted for the bogie suspension at rear based on its advantages. The noises generated from the vehicle in the field includes engine noises and flow noises and hence it is very difficult to clearly discern the noise generated from suspension system of the vehicle [1]. Most suspension system noises do not come from a single part but they are caused by the coupling action between related parts, making it difficult to clearly identify the exact cases. This paper details the overall approach to identify the bogie suspension noise on a commercial vehicle and countermeasures to reduce the same.
2013-09-24
Technical Paper
2013-01-2356
Boris Beloousov, Tatiana I. Ksenevich, Vladimir Vantsevich, Dmitry Komissarov
Two characteristics of terrain mobility are essential in designing an unmanned ground vehicle (UGV): (i) the ability of a vehicle to move through terrain of a given trafficability and (ii) the obstacle performance, i.e., the ability to avoid, interact with and overcome obstacles encountered on a preset route of a vehicle. More attention has been given to the vehicle geometry including selection of the angles of approach and departure, radii of longitudinal and lateral terrain mobility, and the steering system configuration. An essential effect is exhibited by the tire properties in their interaction with the support surface; this, in turn, affects traction properties of the wheel and, thus, vehicle terrain mobility. However, the influence of power distribution between the driving wheels together with vehicle steering system on the two above-listed characteristics of terrain mobility has not been considered in depth.
2013-09-24
Technical Paper
2013-01-2354
Gediz Kulac, Berzah Ozan, Yahya Oz
Steering performance as a vehicle dynamics attribute of a heavy commercial vehicle is dependent on series of design and tunable steering system parameters. The driver steering input as angle and torque is transmitted through steering column to the steering box with a combined function created by the steering column angles and orientations. In case the angle and torque transmission from steering wheel to steering box through steering column cannot be linearized because of the design constraints, the steering column input and output torque, angle and angular speed relations should be optimized for a good vehicle dynamics performance and in compliance with the OEM brand DNA This paper represents series of CAE analyses, optimization studies, verification tests and subjective evaluations related to the tunable parameters of the steering column.
2013-09-24
Technical Paper
2013-01-2351
Vijay Antony John Britto, Ekambaram Loganathan, Sivasankaran Sadasivam, Kalyankumar Hatti, Sai Sankaranarayana
Driver fatigue is one among the important factors for accidents, causing loss of precious life and property. Apart from long driving hours, driver fatigue can be due to poor ride quality, cabin noise, high vibration levels and poor ergonomics. In last few years, there has been enough emphasis to improve the noise and vibration comfort of commercial vehicles, which is governed by vibration levels at tactile points such as steering wheel, gear lever, pedal and seat. Steering wheel vibration is an important element which driver uses to express about the vehicle vibration quality. Design of steering system is driven by ergonomics, packaging, durability, safety, vibration & ride and handling requirements. This paper discusses about methodology of steering assembly development for Noise Vibration and Harshness (NVH) performance of commercial vehicle.
2013-09-24
Technical Paper
2013-01-2352
Paul C. Niglas
The new RSDII (Reduced Stopping Distance, phase 2) regulation creates an increased emphasis by the heavy truck industry to ensure that brake systems are properly chosen and optimized. This regulation has led to vehicles being fitted with much more powerful brakes. However, despite the intent of these new brakes to provide larger braking forces for shorter stopping distances, the performance of vehicles is still limited by the maximum friction coefficient between the vehicle's tires and the road. In order to get the most out of these new brakes, it is essential that the entirety of the vehicle be taken into account. With the use of a hardware-in-the-loop simulation tool, this paper will present stopping data predictions from a variety of vehicles of varying brake torque and wheelbase. It will be shown how these factors change the way a vehicle behaves under panicked stopping situations.
2013-09-24
Technical Paper
2013-01-2350
Matt Kero
The commercial vehicle industry has seen regulations create new requirements over the last few years. Reductions to stopping distance, improvements to vehicle emissions, and the overall need for lighter weight vehicles has caused the commercial vehicle industry to look for new solutions to meet these needs. One such solution is light-weight aluminum metal matrix composite (MMC) brake drums. Aluminum MMC brake drums create the opportunity to reduce weight, lower brake temperatures, improve brake life cycle, and improve brake performance. During the evaluation of these aluminum MMC components it has been seen that existing procedures do not create accurate comparisons for this new material. Current procedures were designed and implemented for cast iron braking solutions. This paper will outline two procedures; FMVSS121 dynamometer burnishing and SAE J2115 wear performance testing, that do not allow direct comparisons from brake system to brake system to be made.
2013-09-24
Technical Paper
2013-01-2349
Naseem A. Daher, Monika Ivantysynova
Modern on-road vehicles have been making steady strides when it comes to employing technological advances featuring active safety systems. However, off-highway machines are lagging in this area and are in dire need for modernization. One chassis system that has been receiving much attention in the automotive field is the steering system, where several electric and electrohydraulic steering architectures have been implemented and steer-by-wire technologies are under current research and development activities. On the other hand, off-highway articulated steering vehicles have not adequately evolved to meet the needs of Original Equipment Manufacturers (OEM) as well as their end customers. Present-day hydrostatic steering systems are plagued with poor energy efficiency due to valve throttling losses and are considered passive systems relative to safety, adjustability, and comfort.
2004-10-26
Technical Paper
2004-01-2722
Klaus Steinel, Gerhard Tebbe
Comfort requirements have significantly increased in recent years, even in the commercial vehicle sector. Transmission noise, caused by higher engine excitation (due to emission changes), can be reduced with a new torsional damper in the clutch disc, with a special idle damper. Up until now, free play (sometimes referred to as backlash) in the clutch or transmission helped reduce idle rattle. In many cases this simple solution is no longer adequate. This paper explains dynamic behavior during idling and provides the background for understanding the causes of rattle noise.
2004-10-26
Technical Paper
2004-01-2712
Prasad Mangalaramanan, Dennis Dauber
Traditional methods often lead to truck component designs that are overly conservative. The ever-increasing need to reduce operational costs demands innovative means for producing parts that are light, durable and capable of carrying more loads. This paper discusses the far-reaching advantages of shape-optimization, beyond the fundamental stipulation of weight reduction. A suspension link is considered to demonstrate the benefits of an optimally shaped component.
2004-10-26
Technical Paper
2004-01-2733
William P. Fornof
A coalescing filter is typically used in a compressed air system to remove liquid and oil aerosols. A coalescing filter is most efficient when located downstream of an air dryer. The air dryer removes most of the liquid oil condensed in the compressor discharge line. Measuring the percent of oil removed by a coalescing filter is useful for determining efficiency. This paper covers a laboratory method to reproduce oil aerosols much like the filter will see in an actual application. High duty cycles produce the maximum amount of oil from the compressor. The air dryer acts as pre-filter for the coalescing filter. The coalescing filter element and its associated housing should be tested as a unit since the element's inherent efficiency is effected by the design of the housing.
2004-10-26
Technical Paper
2004-01-2694
Stefano J. Cassara, David C. Anderson, J. Magnus Olofsson
The accurate prediction of commercial-vehicle ride and handling performance with computer simulation tools is dependent on the level of correlation between the computer model and experimental data. Correlating vehicle attributes to physical test data is often challenging due to the large number of degrees of freedom - and, correspondingly, the large number of tunable parameters - typically required to accurately model vehicle behavior. A high level of interaction between input parameters and vehicle attributes further complicates the task. As a result, this type of correlation is a multi-objective optimization exercise in which the judicious planning of supporting test activity is critical to achieving the right level of model accuracy with an acceptable amount of resource investment. This paper discusses the methodology implemented in the validation of a tractor-semitrailer ADAMS model for both ride and handling simulations and presents the results obtained.
2004-10-26
Technical Paper
2004-01-2647
Douglas A. Swift, Carl Talaski
A sensor system was developed to measure loads in truck wheels. The system has the unique capability to measure each individual wheel in a dual set. This paper covers the development and testing of the system. Sample data from road tests is also presented.
2004-10-26
Technical Paper
2004-01-2709
Caner Demirdogen, Jim Ridge, Paul Pollock, Scott Anderson
Design of suspension systems for Heavy Trucks is always challenging due to the heavy loads the system is exposed to and the long life requirements for the total system. Historical solutions were over designed structures to get the needed life and reliability. This always meant heavier parts. In today's economy, the vehicle weight of commercial heavy trucks is a very important feature for our customers and the end user. Lighter, well-designed suspension components provide better ride quality to the drivers through lower un-sprung weight, lower initial costs and greater payloads. The latest available structural optimization techniques are a business requirement for tomorrow's products. This paper describes the developed methodology used by DANA Engineers to design a weight optimized upper control arm for Commercial Heavy Trucks in step by step fashion. The method starts with determining the loads on the component part.
2013-01-09
Technical Paper
2013-26-0060
V. Faustino, T. Srinivasulu, Arun S
There are no Indian and International standards on load bearing elements. There is a British Standard which specifies only the load requirements of Headboard, side walls and rear gate in case of sudden braking. This paper specifies in detail the load bearing elements and through Computer Aided Engineering (CAE) simulation, the percentage of load that can be borne by the load bearing elements under different types of load shifting has been determined.
2013-01-09
Technical Paper
2013-26-0145
S. Narayanan, S. Mithun, T. Sahul Hameed
A lift axle suspension system in a heavy commercial vehicle enables raising and lowering of the lift axle depending on the vehicle load condition. The states (raising and lowering) of the axle will be in logical sequence which depends on the vehicle load, ignition state, gear state and traction requirement. To arrive this complicate logic, the Lift Axle Control valve is designed. This LACV is an intricate assembly of pneumatic 3/2 valve, 5/2 valve, relay valve and solenoid valves. To predict the performance of this valve under various vehicle conditions, the entire valve is modeled in one of the commercially available multi-domain physical modeling software employing bond graph technique and lumped system and the performance is predicted. This paper deals with the modeling of LACV, simulation of misbehavior of LACV under certain condition, and the design analysis carried out to arrive design solution.
2013-01-09
Technical Paper
2013-26-0148
Vyankatesh Madane, Akshay Baviskar, Anil Gaikwad, S. S. Sane
Light commercial vehicles are extension of three wheelers due to their need for simplicity and load carrying capacity. Smaller vehicle being simpler, have engine mounted at the rear. This give an added advantage in term of simple and light weight design and thus cost effective and have low engine noise and vibration in cabin. In many of the light commercial vehicles, which have been downsized from the bigger vehicles like trucks, have the aggregates designs similar to those of trucks like the drive line extending from the mid engine to rear axle having integral differential. The axle carries the leaf springs for giving robust look as well the load carrying capacity. In the new rear suspension design of the light commercial vehicle, advantage of the mid position engine concept and rear engine concept have been captured. This paper is discusses the design philosophy and the packaging of the same along with criteria for design.
2013-01-09
Technical Paper
2013-26-0150
Jeevan N. Patil, Sivakumar Palanivelu, Ajit Kumar Jindal
Air brake system is widely used in heavy duty trucks and buses due to its great performance and efficiency. Dual brake valve (DBV) is one the of major and crucial component of an air brake system as it is controlling the air flow from reservoir to brake chamber during braking operation. Currently, due to its own complexity, it is very difficult for designer to optimize different parameters. As experimentation is tedious and time consuming task, hence it is very important to have mathematical model of DBV during in early design stage. Differential equations have been formulated for individual component of DBV such as primary piston, primary valve, relay piston, and relay valve etc. system level mathematical model has been formulated and implemented in Matlab/Simulink to capture the dynamic pressure characteristic of DBV. At the same time mathematical model of DBV has been created in AMESim to check the validity of approach.
2013-01-09
Technical Paper
2013-26-0157
Bollishetty Sreedhar, Chandrakant Deshmukh
Multi Body Dynamics (MBD) simulation software is used in product development cycle to reduce the lead time to market. These software have standard parametric templates for modeling metallic suspension systems, which can be quickly modified and used in full vehicle models for ride, handling analysis and the durability load predictions. Generally every Original Equipment Manufacturer (OEM) has unique air suspension arrangement and hence standard template is not available for air suspension modeling in commercial MBD software. Air suspension with self-leveling control mechanism is preferred over metallic suspension in the commercial passenger vehicle like bus for smooth ride comfort. Hence custom made templates for these systems need to be developed for use with MBD software. In this paper, a simplified model of air suspension is presented.
2013-01-09
Technical Paper
2013-26-0153
Prashant R. Pawar, Yogesh V. Dhage, M. R. Saraf, Vratislav Ondrak
The demands for safe, reliable, lighter, energy efficient and competitively priced products put a new emphasis on predictability of rolling bearing performance. This has prompted designers and engineers to estimate bearing life and optimize the design by taking into account different market requirement. Estimation of actual dynamic bearing load and life for specified class of vehicle depends upon various factors such as usage pattern, vehicle Gross Vehicel Weight (GVW), type of roads, speed, driving pattern, geographical area, ambient temperature, acceleration etc. For estimation and prediction of life of the particular wheel bearing type it is required to identify and measure customer usage loads for different targeted markets. The measurement maps all the affecting parameters to arrive at a generalized duty cycle for bearings.
2013-10-07
Technical Paper
2013-36-0245
Getúlio Soares Junior, Jean Cory de Souza Silva, Rafael Fortuna Pizzi, Vinícius Mendes Guarenghi, Ricardo Santarosa
The anti-lock brake system, known as ABS, whose the main function is to ensure directional stability and, consequently, the handling of the vehicle in an emergency brake application. Acting on the brakes, prevents the wheels are locked in extreme situations as well as in various applications on low friction floors. The most common applications found in our market are vehicles whose brakes are fully hydraulic or pneumatic. The purpose of this paper is to present all ABS development phases on an “air over hydraulic” vehicle, in other words, the front brake is acted by a hydraulic system and the rear by a pneumatic.
2013-05-15
Technical Paper
2013-36-0029
Artur Safont Gutierrez, Silvia Faria Iombriller, Wesley Bolognesi Prado, Daniel Novello, Leandro Maggioni, Alexandre Roman, Carlos Henrique Selle Pereira
During the development of a new friction material, besides the interface between lining/drum is also fundamental take in account all aspects involving the attachment of the linings on the brake shoes. This paper presents an optimization approach to the development and manufacturing parameters of brake linings, applied on medium and heavy duty commercial vehicles, aiming to assure the correct specification of the riveted joint clamp forces. These evaluations were conducted based on the quality tools documents and the theoretical aspects of the product usage as well as the modeling of key elements of the referred mechanism throughout various known applications. A calculation methodology was developed based on brake geometry, its generated forces and braking reactions required for each vehicle family.
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