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Viewing 151 to 180 of 8158
2016-10-25
Technical Paper
2016-36-0204
Julio Cesar Lelis Alves, Flavio Koiti Maruyama, Leonardo José Della Volpe, Filipe Fabian Buscariolo, Felipe Magazoni
Abstract Within the advances in Computer Fluid Dynamics algorithms and High Performance Computing, large clusters become available at low costs allowing virtual simulations that were not possible some years ago at reasonable costs and time. This work uses intensively this condition and applies these advances on brake system optimization. The methodology developed in the present work verifies the best angular position for caliper inside the wheel to reduce the rotor temperature during braking process such as downhill procedure. Thus, this method is applied to a mini-VAN vehicle, where the best position is found, based on two design parameters: rotor temperature and convection heat transfer coefficient. This study shows that the most suitable position for initial selection is the first one.
2016-10-25
Technical Paper
2016-36-0309
Adriano Schommer, André Ogliari, Mario Martins
Abstract In the way of achieving maximum performance of a racecar several aspects of it have to be optimized. The whole picture of vehicle performance involves crossing data to find relationship among systems and identifying trends, pitfalls and optimum points. In this paper, a straightforward software tool for tire data analysis is developed and described. The software aims to integrate tire data analysis in early stages of the development process of a Formula SAE racecar. In addition, it is thought to be a learning environment to fresh team members. To establish and achieve the necessary goals, an affordancebased model was used to elicit user needs. Regarding the tires, it was possible to precisely point out what data is required to quickly fit a Pacejka tire mode and to cross raw tire data of different tires and preview the steady state balance of a vehicle.
2016-10-25
Technical Paper
2016-36-0348
André de Moura Oliveira, Elvis Bertoti, Jony Javorski Eckert, Rodrigo Yassuda Yamashita, Eduardo dos Santos Costa, Ludmila Corrêa de Alkmin e Silva, Franco Giuseppe Dedini
Abstract The need for improved fuel economy for road vehicles has increased the interest in hybrid electric vehicle (HEV) and recovering vehicle energy. This paper aims to evaluate the amount of kinetic energy that could be restored through regenerative braking in a HEV. This work will not resort the Brazilian urban driving cycle NBR 6601, for this cycle does not fully represent a pattern of traffic faced regularly in urban areas, which is typically composed of heavy traffic and long periods of idleness. Therefore, a new drive cycle will be developed that better represents the Brazilian traffic. Also, considering the shortage of energy resources, the large amount of energy dissipated as heat during braking a vehicle is a recurring concern. Therefore, measuring the maximum available energy that could be restored through regenerative braking is the first step towards estimating the profit of using this technology and how it would pay off the investment in the long run.
2016-10-25
Technical Paper
2016-36-0400
Carlos Abílio Passos Travaglia, Luiz Carlos Rolim Lopes
Abstract Great numbers of studies in sliding wear phenomena use the wear rate to quantify material losses. However, in more recent works, some authors have been tried to characterize the wear phenomena by means of the energy dissipation between the contact surfaces of the bodies. The aim of this work is to create an analytical model capable to relate the total energy dissipated by a friction material during a bench wear test and data collected directly in a vehicle brake, in order to predict the durability of this component in service life. To attain this aim, the concept of specific wear volume, SWV, is adopted. The specific wear volume is the relationship between the material wear volume and the energy dissipated during a sliding wear process. In addition, a method to calculate the energy dissipation on friction materials is presented.
2016-10-25
Technical Paper
2016-36-0457
Weber Ferreira Veloso, Marcela Rodrigues Machado Garcia, Sabrina Glicéria Firmino, Juliana Queiroga Gazaniga de Assis, Diego Palhares de Faria
Abstract Through a computing transient thermal analysis, the team evaluated the quality of the material and its resistance to thermal fatigue by a comparative method. With the steel used in 1020 failed in 2014, for the team Formula UFMG, the 1020 steel, 1045, 1070 and stainless steel 304 were compared, where the stainless steel was the parameter of better resistance to thermal cracking. The main calculated parameters were subjected to empiric validations and the best material has been applied and used in the 2015 season. The use of the disks in a competition and in a battery of tests superior to 2014, permitted the evaluation of the final result of applying the material.
2016-10-25
Technical Paper
2016-36-0444
L.C. Gertz, A.F.A. Rodrigues, A. Cervieri, J.I. Salis, J.S. Theis, G.S. Rolim, A.B. Oliveira
Abstract This study aims to determine the force acting on the rod ball end of an automotive suspension prototype from competition, participant in the Brazilian Tourism Championship 2016, used in training and to determine the fast lap time. The rod ball end is manufactured in SAE 4140 steel with heat treatment (body and ball) and the bush of polyacetal. To determine the force on the rod ball end the lower balance arm was converted into two load cells, through the setting of strain gage in each of the arms that compose it. It was recorded runway images with a camera in the cockpit and another camera placed inside the vehicle with the rear wheel housing, making possible to observe the suspension movement. When the prototype makes a chicane, the centripetal force is higher because the radius curve is small, when is accelerated it generates a force in line with the wheel, the front bar is compressed even more, and the rear is tensioned, that generates a load near to zero in this bar.
2016-10-25
Technical Paper
2016-36-0140
Rodrigo Luiz de Campos
Abstract This work aims to summarize in a single form all legal requirements that dictates the minimum safety compliance required by government edicts to any wheel manufacture to have their products available for passenger or light truck vehicle in any country around the world in the year of 2016. It is not intention of this paper compare or discuss the different requirement among the countries but indicate to the manufactures of wheels what legal edicts they need to meet in case they are willing to go overseas to explore the wheel market of other country. Before start designing wheels for passenger or light truck application, any manufacture should be sure about what the government of the new market demands for wheels when installed on vehicle axis or just available as temporary spare.
2016-10-25
Technical Paper
2016-36-0242
A. C. R. Ramos, R. B. Santos, C. A. P. Melo, I. C.S. Perez
Abstract Noise, vibration and Harshness in the automotive industry became important mainly because the development of modern automobiles and the increased of customer demands for quieter vehicles and with comfortable vibration levels. The sources of vibration and noise inside the vehicle are caused by the engine, tires, transmission systems, suspension, air conditioning, among others. In this work, vibroacoustic transfer function is obtained to analyze the internal noise in two sport utility vehicle with distinctive silhouette. Furthermore, it was analyzed the influence of elastomeric bushings rigidity of the damper in reducing internal noise and vibration and the effect of adding mass in some framework positions for attenuation of vibration peaks due to structural resonance.
2016-10-25
Technical Paper
2016-36-0239
Lucas Iensen Bortoluzzi, Adriano Schommer, Mario Martins, Alexandre Aparecido Buenos
Abstract In many vehicle motorsport categories, the one of the most important factors that lead a team to the victory is the suspension setup. Parameters like roll stiffness and camber changing are essential to the vehicle behavior during a driving situation. To handle these variables, features like suspension hardpoints arrangement, pivot points position and spring stiffness can be settled. However a setup only will perform a desirable effect if the chosen configuration does not change. Ideally, to make it possible, every component that holds suspension loads (suspension members, mounting plates and chassis) would have to be infinitely rigid. Even though it is not achievable, the existing deformation can be small enough to be negligible when compared with suspension displacement. In order to reach this target, this paper introduce a spring modeling and a Finite Element multibody modeling process of a Formula SAE prototype’s suspension and chassis.
2016-10-17
Technical Paper
2016-01-2233
Matthew C. Robinson, Nigel N. Clark
Abstract The free piston engine combined with a linear electric alternator has the potential to be a highly efficient converter from fossil fuel energy to electrical power. With only a single major moving part (the translating rod), mechanical friction is reduced compared to conventional crankshaft technology. Instead of crankshaft linkages, the motion of the translator is driven by the force balance between the engine cylinder, alternator, damping losses, and springs. Focusing primarily on mechanical springs, this paper explores the use of springs to increase engine speed and reduce cyclic variability. A numeric model has been constructed in MATLAB®/Simulink to represent the various subsystems, including the engine, alternator, and springs. Within the simulation is a controller that forces the engine to operate at a constant compression ratio by affecting the alternator load.
2016-09-27
Technical Paper
2016-01-8044
Guoyu Feng, Wenku Shi, Henghai Zhang, Qinghua Zu
Abstract In order to predict the fatigue life of thrust rod heavy duty commercial vehicle balanced suspension, based on the continuum mechanics theory, the fatigue life prediction model of rubber with equivalent effect as damage parameter is established. Based on the equivalent stress and fatigue cumulative damage theory, the fatigue damage evolution equation of rubber material expressed by stress is derived by using the strain energy function. The general fatigue life model is established by using the maximum logarithmic principal strain as the damage parameter. The finite element model of the thrust rod is established, and the stress distribution of the spherical hinge rubber layer and the easy damage area are analyzed. Based on the equivalent stress calculation results and the axial tension stress and strain data of the rubber material, the accuracy of the results of the finite element calculation is verified.
2016-09-27
Technical Paper
2016-01-8028
Chao Yang, Nan Xu, Konghui Guo
Abstract This paper focuses on the modeling process of incorporating inflation pressure into the UniTire 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 these 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 there are 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
2016-01-8032
Anatoliy Dubrovskiy, Sergei Aliukov, Andrei Keller, Sergei Dubrovskiy, Alexander Alyukov
Abstract In this paper we consider a new design of adaptive suspension systems of vehicles with better technical characteristics and functional abilities in comparison with existing designs. We have developed the following main suspension components of vehicles: a lockable adaptive shock absorber with a wide range of control performance, implementing "lockout" mode by means of blocking adaptive shock absorber, and an elastic element with progressive non-linear characteristic and automatic optimization of localization of work areas. Advantages of our developments in the vehicle suspensions are the following: 1) when the vehicle is in a wide range of speeds in a so-called "comfort zone", we have managed, by applying the non-linear elastic element, to reduce significantly the stiffness of the elastic suspension elements in compare with the regular structures - at least in two times.
2016-09-27
Technical Paper
2016-01-8037
Nan Xu, Konghui Guo, Yiyang Yang
Abstract The tire mechanics characteristics are essential for analysis and control of vehicle dynamics. Basically, the effects of sideslip, longitudinal slip, camber angle and vertical load are able to be represented accurately by current existing tire models. However, the research of velocity effects for tire forces and moments are still insufficient. Some experiments have demonstrated that the tire properties actually vary with the traveling velocity especially when the force and moment are nearly saturated. This paper develops an enhanced brush tire model and the UniTire semi-physical model for tire forces and moments under different traveling velocities for raising need of advanced tire model. The primary effects of velocity on tire performances are the rubber friction distribution characteristics at the tire-road interface.
2016-09-27
Technical Paper
2016-01-8085
Yanjun Ren, Gangfeng Tan, Kangping Ji, Li Zhou, Ruobing Zhan
Abstract The hydraulic retarder is an auxiliary braking device generally equipped on commercial vehicles. Its oil temperature change influences the brake performance of hydraulic retarder. The Organic Rankine Cycle (ORC) is a good means to recover exhausted heat. Moreover, it can cool oil and stably control oil temperature with the help of heat absorption related with evaporation. Comprehensively considering the heat-producing characteristics of hydraulic retarder and the temperature control demand, the aimed boundary conditions are determined. Also the changing rules about the working medium flow rate are obtained. In this work, the heat-producing properties of hydraulic retarder under different conditions and the oil external circulating performance is firstly analyzed. By researching the system’s adaptation to the limiting conditions, the aimed temperature to control is prescribed.
2016-09-27
Technical Paper
2016-01-8119
Jun Sun, Xiaofei Pei, Xuexun Guo, Yanqiang Zhao
Abstract In order to overcome hysteresis and dead zone problems caused by friction for the proportional solenoid valve, and improve rapidity and stability of the pneumatic system on hydraulic retarder, a closed-loop control strategy based on valve coil current was proposed. The high-frequency low-amplitude dither signal was introduced into the proportional solenoid valve. With the proper dither signal, the stick-slip motion of the valve core was transformed into a steady one, and its dynamic performance was improved. Consequently, response time of retarder was reduced during gear changing. The proportional valve coil current was measured as a feedback for a closed-loop control strategy. Combining with the closed-loop strategy, the PI control algorithm was adopted to make sure that valve current was in accordance with the target value. Pulse Width Modulation (PWM) signal was used for the driving of proportional solenoid valve.
2016-09-27
Technical Paper
2016-01-8012
Daniel E. Williams, Amine Nhila, Kenneth Sherwin
Abstract 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
2016-01-8033
Guoying Chen
Abstract According to the vehicle’s driving conditions, electronically controlled air suspension (ECAS) systems can actively adjust the height of vehicle body, so that better ride comfort and handling stability will be achieved, which can’t be realized by traditional passive suspension. This paper presents a design and implementation of ECAS controller for vehicle. The controller is aimed at adjusting the static and dynamic height of the vehicle. To exactly track the height of the vehicle and satisfy the control demand of air suspension, a height sensor decoding circuit based on the inductance sensor is designed. Based on it, a new height control algorithm is adopted to achieve rapid and precise control of vehicle height. To verify the function of the designed controller and the proposed height control algorithm, an air spring loading test bench and an ECU-in-loop simulation test bench are respectively established.
2016-09-27
Technical Paper
2016-01-8114
Massimiliano Ruggeri, Pietro Marani, Michele Selvatici
Abstract Stationary (parking) brake is a very important and safety critical function in many classes of machines. The new transmissions and the “by wire” systems increase the criticality of the role of stationary brake, as it is also an emergency (secondary) brake, and it’s often used to hold the vehicle when the transmission is not locking the wheels. As an example, dual clutch and power-shift transmission gear systems, as well as hydrostatic transmissions under certain circumstances, are often unable to hold the vehicle stopped and this function is provided by the stationary brake. Due to the main need of having the brake actuated when vehicle is stopped, without any hydraulic and electric power, the brake configuration is normally a “negative” configuration, usually called “spring applied” because of the actuator configuration, but this configuration causes the brake actuation when de-energized, even in case of system failure.
2016-09-27
Technical Paper
2016-01-8042
Danna Jiang, Ying Huang, Xiaoyi Song, Dechun Fu, Zhiquan Fu
Abstract This paper describes a uniform Hardware-In-the-Loop (HiL) test rig for the different types of Electronic Braking System (EBS). It is applied to both modular testing and integrated testing. This test rig includes a vehicle dynamic model, a real-time simulation platform, an actual brake circuit and the EBS system under test. Firstly, the vehicle dynamic model is a highly parameterized commercial vehicle model. So it can simulate different types of commercial vehicle by different parameter configurations. Secondly, multi-types of brake circuit are modeled using brake components simulation library. So, it can test the EBS control unit independently without the influence of any real electro-pneumatic components. And a software EBS controller is also modeled. So it can test the algorithm of EBS offline. Thirdly, all real electro-pneumatic components without real gas inputted are connected to the real-time test platform through independent program-controlled relay-switches.
2016-09-27
Technical Paper
2016-01-8038
Yunbo Hou, Yang Chen, Mehdi Ahmadian
Abstract This paper studies the effect of different longitudinal load conditions, roundabout cross-sectional geometry, and different semi-truck pneumatic suspension systems on roll stability in roundabouts, which have become more and more popular in urban settings. Roundabouts are commonly designed in their size and form to accommodate articulated heavy vehicles (AHVs) by evaluating such affects as off-tracking. However, the effect of the roadway geometry in roundabouts on the roll dynamics of semi-tractors and trailers are equally important, along with their entry and exit configuration. , Because the effect of the roundabout on the dynamics of trucks is further removed from the immediate issues considered by roadway planner, at times they are not given as much consideration as other roadway design factors.
2016-09-27
Technical Paper
2016-01-8079
Zhiwei Zhang, Gangfeng Tan, Mengying Yang, Zhongjie Yang, Mengzuo Han
Abstract The hydraulic retarder is an important auxiliary braking device. With merits such as its high braking torque, smooth braking, low noise, long service life and small size, it is widely used on modern commercial vehicles. Transmission fluid of traditional hydraulic retarder is cooled by engine cooling system, which exhausts the heat directly and need additional energy consumption for the thermal management component. On account of the working characteristics of hydraulic retarder, this study designs a set of waste heat recovery system based on the Organic Rankine Cycle (ORC). Under the premise of ensuring stable performance of hydraulic retarder, waste heat energy in transmission fluid is recycled to supplement energy requirements for cooling system. First of all, a principle model, which is scaled down according to D300 retarder`s thermal power generation ration of 1:100, is established.
2016-09-27
Technical Paper
2016-01-8112
Jorge Leon, Jose M. Garcia, Mario J. Acero, Andres Gonzalez, Geng Niu, Mahesh Krishnamurthy
Abstract In order to improve efficiency and increase the operation of electric vehicles, assistive energy regeneration systems can be used. A hydraulic energy recovery system is modeled to be used as a regenerative system for supplementing energy storage for a pure electric articulated passenger bus. In this study a pump/motor machine is modeled to transform kinetic energy into hydraulic energy during braking, to move the hydraulic fluid from the low pressure reservoir to the hydraulic accumulator. The simulation of the proposed system was used to estimate battery savings. It was found that on average, approximately 39% of the battery charge can be saved when using a real bus driving cycle.
2016-09-27
Technical Paper
2016-01-8102
Rıfat Kohen Yanarocak, Yavuz Can Ozkaptan
Abstract The intake and exhaust valve spring of a 12.7L heavy duty diesel engine was instrumented with torque/shear rosette type strain gages to measure torsional stresses applied on the springs under different engine operating conditions. The engine was tested with no load, partial load and full load conditions and the effect of engine brake switch loading operation on the springs is investigated. Additional measurement of the valve lift motion and the peak fire pressure values from exactly the same cylinder were conducted to better understand the exact timing of the forces applied on the spring. This study gave an insight to the design engineer to determine the dynamic safety margin of the spring under permissible torsional stress values and optimize the material type of the spring accordingly. Another achievement is to measure any possible unpredictable torsional stress values occurred during engine operation when the engine brake is turned on/off and correlate the CAE model.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Abstract Typically, earthmoving machines do not have wheel suspensions. This lack of components often causes uncomfortable driving, and in some cases reduces machine productivity and safety. Several solutions to this problem have been proposed in the last decades, and particularly successful is the passive solution based on the introduction of accumulators in the hydraulic circuit connecting the machine boom. The extra capacitance effect created by the accumulator causes a magnification of the boom oscillations, in such a way that these oscillations counter-react the machine oscillation caused by the driving on uneven ground. This principle of counter-reacting machine oscillations through the boom motion can be achieved also with electro-hydraulic solutions, properly actuating the flow supply to the boom actuators on the basis of a feedback sensors and a proper control strategy.
2016-09-27
Technical Paper
2016-01-8027
Stefan Steidel, Thomas Halfmann, Manfred Baecker, Axel Gallrein
Abstract Rolling resistance and tread wear of tires do particularly influence the maintenance costs of commercial vehicles. Although 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.
2016-09-27
Technical Paper
2016-01-8031
Nicholas Atanasov, Evan Chenoweth
Abstract Since the introduction of electronically controlled air suspension (ECAS) systems in the nineties, no major improvements have been made in the realm of controlling air suspensions in the heavy duty truck market. Despite the lack of improvement, a need exists for intelligently controlled air suspension systems, specifically systems which can be applied to 6x2 axle configurations in the North American market. This study outlines a concept proposal for a novel suspension control concept which encompasses traction control capabilities in addition to suspension control for improved fuel efficiency benefit. The major novelty of the concept is that, by utilizing specific axle configurations and tires, a shift in pressure from the driven to the non-driven axles may result in improvements in the overall fuel economy of the vehicle.
2016-09-27
Technical Paper
2016-01-8006
John Reid, Stewart Moorehead, Alex Foessel, Julian Sanchez
Abstract A transformation of agriculture reached commercial reality at the beginning of this century as automated steering of agricultural machine systems increased the productivity and convenience in crop production systems. Following guidance, additional technologies have resulted in increasing optimized machine productivity. Today, integrated worksite solutions through machine and information management continues to transform agriculture. This is the precursor to autonomous worksite solutions that lead to the optimization of the worksite ecosystem. This paper will review the progress from the perspective of the customer value provided by increasing automated systems and the industry execution of autonomous driving technologies and will enable the pathways to autonomous worksites.
2016-09-27
Journal Article
2016-01-8010
M. Kamel Salaani, David Mikesell, Chris Boday, Devin Elsasser
Abstract Field testing of Automatic Emergency Braking (AEB) systems using real actual heavy trucks and buses is unavoidably limited by the dangers and expenses inherent in crash-imminent scenarios. For this paper, a heavy vehicle is defined as having a gross vehicle weight rating (GVWR) that exceeds 4536 kg (10,000 lbs.). High fidelity Hardware-in-the-Loop (HiL) simulation systems have the potential to enable safe and accurate laboratory testing and evaluation of heavy vehicle AEB systems. This paper describes the setup and experimental validation of such a HiL simulation system. An instrumented Volvo tractor-trailer equipped with a Bendix Wingman Advanced System, including the FLR20 forward looking radar and AEB system, was put through a battery of different types of track tests to benchmark the AEB performance.
2016-09-27
Journal Article
2016-01-8029
Chrysostomos-Alexandros Bekakos, George Papazafeiropoulos, Dan J. O'Boy, Jan Prins, George Mavros
Abstract A novel semi-analytical solution has been developed for the calculation of the static and dynamic response of an off road tire interacting with a deformable terrain, which utilizes soil parameters independent of the size of the contact patch (size-independent). The models involved in the solution presented, can be categorized in rigid and/or pneumatic tires, with or without tread pattern. After a concise literature review of related methods, a detailed presentation of the semi-analytical solution is presented, along with assumptions and limitations. A flowchart is provided, showing the main steps of the numerical implementation, and various test cases have been examined, characterized in terms of vertical load, tire dimensions, soil properties, deformability of the tire, and tread pattern. It has been found that the proposed model can qualitatively capture the response of a rolling wheel on deformable terrain.
Viewing 151 to 180 of 8158