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Viewing 1 to 30 of 7987
2016-10-17
Technical Paper
2016-01-2233
Matthew C. Robinson, Nigel N. Clark
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 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 primarily 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 variance. 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 tries to force the engine to operate at a fixed compression ratio by affecting the alternator load.
2016-09-27
Technical Paper
2016-01-8028
Chao Yang, Nan Xu, Konghui Guo
This paper focuses on the modeling process of incorporating inflation pressure into the UniTire tire model for pure cornering. Via observing and manipulating the tire experimental data, the effects of inflation pressure on the tire cornering property are analyzed in detail, including the impacts on cornering stiffness, the peak friction coefficient, the curvature of transition region and the pneumatic trail. And the brief mechanism explanations are also given for some of those impacts. The results show that some effects of inflation pressure are similar to that of vertical load on the non-dimensional tire cornering property, and also have strong interactive effects between the two operating conditions. Therefore, in order to obtain concise expressions, the inflation pressure is incorporated into the UniTire tire model by analogy with the expressions for vertical load, and the interactive effects are also taken into account.
2016-09-27
Technical Paper
2016-01-8037
Nan Xu, Konghui Guo, Yiyang Yang
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
2016-01-8038
Yunbo Hou, Yang Chen, Mehdi Ahmadian
This paper primarily studies the effect of 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 offtracking. However, the effect of the roadway geometry in roundabout, along with their entry and exit configuration, on the roll dynamics of semi-tractors and trailers are often ignored, mostly because they far removed from the immediate issues commonly considered by civil engineers during roadway design. The cross-sectional geometry of circulatory roadway and truck apron, two key roundabout segments, are studied to evaluate the effect on roll stability of a WB-67 semi-truck in roundabouts, when the truck is equipped with conventional OE suspensions and a balanced pneumatic system.
2016-09-27
Technical Paper
2016-01-8012
Daniel E. Williams, Amine Nhila, Kenneth Sherwin
A large percentage of commercial vehicles transport freight on our interstate highway system. These vehicles spend the vast majority of their duty cycle at high speed maintaining a lane. As steering is integrated into ADAS, objective performance measures of this most common mode of commercial vehicle operation will be required. Unfortunately in the past this predominant portion of the commercial vehicle duty cycle was overlooked in evaluating vehicle handling. This lanekeeping mode of operation is also an important, although less significant portion of the light vehicle duty cycle. Historically on-center handling was compromised to achieve acceptable low speed efforts. With the advent of advanced active steering systems, this compromise can be relaxed. Objective measures of lanekeeping are developed and performance of various advanced steering systems is quantified in this important operating mode.
2016-09-27
Technical Paper
2016-01-8032
Anatoliy Dubrovskiy, Sergei Aliukov, Andrei Keller, Sergei Dubrovskiy, Alexander Alyukov
In the present 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. Our patents confirm the novelty and efficiency of our major design decisions. Advantages of our developments in the vehicle suspensions are the following: 1) it should be noted that 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
2016-01-8033
Guoying Chen
According to the vehicle’s driving conditions, electronically controlled air suspension (ECAS) systems can adjust not only the stiffness and damping of the suspension but also 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. In order to verify the functions of the controller, we construct a test bench whose excitation source is provided by hydraulic system.
2016-09-27
Technical Paper
2016-01-8034
Hao Sun, Guoying Chen
Distributed steering system is new type in vehicle chassis system which uses motors to control the steering angle of each wheel respectively. Relying on the design of steering angle allocation, the handling and stability of the vehicle can be enhanced greatly. In the paper, the steering angle allocation is researched based on a two freedom model considering tire cornering characteristics. Through the obtained relationship between tire side-slip angle and vehicle speed, yaw angular velocity and front wheel angle, combining the Ackerman geometrical relationship, the distributed steering angle allocated suit to front-wheel independent steering (2WIS)and four-wheel independent steering(4WIS)are put forward. After that, simulated analysis are carried out setting tire wear pattern and vehicle stability as target. Improvements in tire wear pattern are determined by evaluating the optimization in tire lateral force, while the vehicle stability is determined by side slip angle.
2016-09-27
Technical Paper
2016-01-8044
Guoyu Feng, Wenku Shi, Henghai Zhang, Qinghua Zu
In order to predict the fatigue life of heavy commercial vehicles thrust rod made of rubber material dumbbell specimens and uniaxial tensile fatigue tests. Based on the measured data samples to the maximum principal strain injury parameters established rubber uniaxial fatigue life prediction models. In the longitudinal tension and compression loading, fatigue life V rods were predicted, and by the uniaxial fatigue test verification, the results show that the maximum principal strain prediction model, the maximum error is less than 10% predicted better results. Show by dumbbell specimen data, the establishment of a spherical hinge rubber life prediction model method, it is possible to predict the fatigue life of the thrust rod.
2016-09-27
Technical Paper
2016-01-8042
Danna Jiang, Ying Huang, Xiaoyi Song, Dechun Fu, Zhiquan Fu
In order to enhance vehicle safety and improve the braking performance, commercial vehicles are usually equipped with electronically braking systems (EBS). But the system is very complex not only because there are many functionalities such as Anti-lock Braking (ABS) and Electronic Stability Control (ESC), but also many electro-pneumatic components such as front axle module and rear axle module. What’s more, there are many different EBSs With different compositions for different vehicle types. These factors bring different requirements for the test rig. This paper describes a uniform Hardware-In-the-Loop (HIL) simulation test rig for the different types of the EBSs. It is also 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. Some special things are as follow. Firstly, the vehicle dynamic model is a highly parameterized commercial vehicle model.
2016-09-27
Technical Paper
2016-01-8027
Stefan Steidel, Thomas Halfmann, Manfred Baecker, Axel Gallrein
Rolling resistance and tread wear of tires do particularly influence the maintenance costs of commercial vehicles. Although the tire labeling is established in Europe, it is meanwhile well-known that, due to the respective test procedures, these labels do not hold in realistic application scenarios in the field. This circumstance arises from the development phase of tires, where the respective performance properties are mainly evaluated in tire/wheel standalone scenarios in which the wide range of usage variability of commercial vehicles cannot be considered adequately. Within this article we address a method to predict indicators for rolling resistance and tread wear of tires in realistic application scenarios considering application-based factors of influence like specific customers, operation circumstances, regional dependencies, fleet specific characteristics etc. Moreover, the prescribed methodology may also be transferred to the prediction of fuel consumption and emission.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Vibrations at the cabin or at the implements of construction machinery represents important drawbacks from the points of view of machine productivity, safety and operator comfort. Oscillations of these machines are particularly relevant due to the absence of shock absorbers, typical of many machines such as wheel loaders, and their use in uneven ground conditions. Several hydraulic solutions have been proposed in the past to reduce oscillations at both the cabin or at the machine boom. Particularly, cabin oscillations can be attenuated by properly counteracting the exciting oscillatory forces from the tires with motion of the boom. Many state of the art machine utilize a passive methods to implement this strategy. The present work introduces a novel active solution, based on the control of the boom actuator without involving modifications of the standard hydraulic system.
2016-09-27
Technical Paper
2016-01-8039
Rui He, Emilio Jimenez, Dzmitry Savitski, Corina Sandu, Valentin Ivanov
Tire modeling plays an important role in the development of an Active Vehicle Safety System. As part of a larger project that aims at developing an integrated chassis control system, this study investigates the performance of a 19” all-season tire on ice for a sport utility vehicle . A design of experiment has been formulated to quantify the effect of operational parameters, specifically: wheel slip, normal load, and inflation pressure on the tire tractive performance. The experimental work was conducted on the Terramechanics Rig in the Advanced Vehicle Dynamics Laboratory at Virginia Tech. The tire performance data collected has then been used to parameterize a Dugoff Tire Model. Compared to existing solutions, this model is attractive in terms of its simplicity, low number of parameters and easy implementation for real-time applications. The curves correlating tire forces and slip ratio were identified by applying zero-phase filtering techniques to the raw test data.
2016-09-27
Journal Article
2016-01-8010
M. Kamel Salaani, David Mikesell, Chris Boday, Devin Elsasser
Rear-end collisions account for roughly 20% of all police-reported heavy truck crashes in 2004, and the heavy truck was the striking vehicle in 60% of these cases. In light of this, Automatic Emergency Braking (AEB), an electronically-assisted means of avoiding or mitigating frontal collision, could have significant safety benefits. Field testing of such systems using real vehicles is necessarily limited by the danger and expense inherent in crash-imminent scenarios, especially when the system is not designed to eliminate all collisions but rather reduce their severity. Hardware-in-the-Loop (HiL) systems have the potential to enable safe and accurate laboratory testing and evaluation of AEB systems. This paper describes the setup and experimental validation of such a HiL system.
2016-09-27
Journal Article
2016-01-8029
Chrysostomos-Alexandros Bekakos, George Papazafeiropoulos, Dan J. O'Boy, Jan Prins, George Mavros
Significant research has been made regarding the interaction of off-road vehicles with deformable terrains, such as snow and sand. The driving response of the tire during travelling on off-road surfaces is crucial for the driving behavior of off-road vehicles. The majority of existing models developed so far are mainly based on empirical or semi-empirical relationships, the pressure-sinkage equation developed by Bekker being the most known. The latter relationship is developed based on certain assumptions, such as invariant soil parameters and a uniform pressure distribution along the width of the tire. These assumptions entail weaknesses in the formulation of the model, which in most cases lead to inadequate validation. In this study, an analytical model of a tire interacting with various types of soils has been developed.
2016-09-27
Journal Article
2016-01-8106
Sameer Kolte, Ananth Kumar Srinivasan, Akilla Srikrishna
As we move towards the world of autonomous vehicles it becomes increasingly important to integrate several chassis control systems to provide the desired vehicle stability without mutual interference. The principles for integration proposed in existing technical literature are majorly centralized which are not only computationally expensive but does not fit the current supplier based OEM business model. An Automotive OEM brings multiple suppliers on-board for developing the Active Safety systems considering several factors such as cost, quality, time, ease of business etc. When these systems are put together in the vehicle they may interfere with each other’s function. Decoupling their function results in heavy calibration causing performance trade-offs and loss in development time.
2016-09-27
Journal Article
2016-01-8104
Ryo Yamaguchi, Hiromichi Nozaki
In this study, we devised the steering assistance control that feedback of the external information from the laser sensor. We have created the emergency avoidance assistance control program by the obstacle detection in the first one, and the cornering assistance control program by the white line detection to second. Improvement in safety by these driving support can be expected. The effect of the created program was to understand by the driving simulator. In addition, we understand the synergistic effect of these steering assist program and chassis control (camber angle control, derivative steering assistance control). In the emergency avoidance assist by the obstacle detection, it made it possible to also be avoided for adding the handle operation at an early stage by the steering assistance in situations where manual operation collide by too late an obstacle avoidance handle operation.
2016-09-27
Technical Paper
2016-01-8112
Jorge Leon, Jose M. Garcia, Mario J. Acero, Andres Gonzalez, Geng Niu, Mahesh Krishnamurthy
Electric motors have energy efficiency and performance advantages over traditional internal combustion engines. Nevertheless, when used for transportation, they have limited ranges due to the state of current energy storage technologies. In order to improve efficiency and increase the range of operation of electric vehicles, complementary energy regeneration systems can be used. A hydraulic energy recovery system is proposed to be used as a regenerative system for supplementing energy storage. This system consists of a hydraulic accumulator, a low pressure reservoir and a hydraulic pump/motor. The pump/motor device transforms kinetic energy into hydraulic energy during breaking, to move the hydraulic fluid from the low pressure reservoir to the hydraulic accumulator. This energy can later can be used to propel the vehicle. The proposed system is particularly useful for vehicles in heavy start-stop traffic and public transportation.
2016-09-27
Technical Paper
2016-01-8114
Massimiliano Ruggeri, Pietro Marani, Michele Selvatici
Stationary brake is a very important and safety related function in many machine types. The new transmissions and the X-by wire systems increase the role of stationary brake criticality, as it is also an emergency brake, and it’s often used to hold the vehicle while the transmission is not locking the wheel in all stationary condition and sometimes if it is faulty. As an example, dual clutch and power-shift transmission gear systems, as well as hydrostatic transmissions are often unable to hold the vehicle stopped and the 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 active power source, the brake configuration is normally a “negative” configuration, but this obviously lead to the brake actuation when de-energized, even in case of fault occurrence.
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
2016-01-8102
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
2016-01-8119
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
2016-01-8006
John Reid, Stewart Moorehead, Alex Foessel, Julian Sanchez
A transformation of agriculture began reached commercial maturity at the beginning of this century that has provided increased customer value from the basis of automating steering system control in crop production systems. The maturity of this technology has led to increased machine system productivity over the last decade leading to increasingly integrated solutions with increased customer value in terms of comfort and productivity. This sets agricultural production ecosystem on a course of new forms of innovation opportunity at the worksite level that is being greatly accelerated by the maturity of the technologies supporting cyber-physical systems. This paper will review the progress from the perspective of the customer value and the industry execution of autonomous driving technologies and will describe the pathways to autonomous worksites, in addition to the challenges to the industry with the emergence of new business models for autonomy.
2016-09-27
Technical Paper
2016-01-8031
Nicholas Atanasov, Evan Chenoweth
Since the presentation of the Electronically Controlled Air Suspension (ECAS) system by WABCO 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 major need exists for controlled air suspension systems, specifically ones which can be applied to 6x2 axle configurations in the North American market. This study outlines a proposal for a novel system which encompasses traction control capabilities in addition to suspension control for improved fuel efficiency benefit. The proposed system includes automatic and manual traction modes based on sensor input or driver control, respectively. The major novelty of the system is that, over a certain speed threshold and utilizing specific axle configurations, the system will increase the pressure in the non-driven axles (dead axles) while reducing pressure in the driven ones.
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.
2016-09-18
Technical Paper
2016-01-1913
Alessandro Sanguineti, Federico Tosi, Andrea Bonfanti, Flavio Rampinelli
Organic brake pads for automotive can be defined as brake linings where the bonding matrix is constituted of high-temperature thermosetting resins. Bonded together inside the polymeric binder are a mix of components (e.g. abrasives, lubricants, reinforcements, fillers, modifiers…), each playing a distinctive role in determining the tribology and friction activity of the final friction material. The herein reported work presents novel inorganic “alkali-activated”-based materials suitable for the production of alternative brake linings (i.e. brake pads), by means of an unconventional low-temperature wet process. Exploiting the hydraulic activity of specific components when exposed to an alkaline environment, such peculiar inorganic materials are capable of coming to a complete hardening without the need of traditional high-temperature energivorous procedures.
2016-09-18
Technical Paper
2016-01-1916
Raffaele Gilardi, Davide Sarocchi, Loredana Bounous
A wide range of different carbon powders is available and currently used in friction materials like coke, graphite and carbon black. The effect of the type of carbon on braking performance has been extensively investigated in the past and it has been demonstrated that graphite can play an important role in copper-free brake pads. However, there are no studies about the influence of carbon powders on the processability of brake pads. Brake pads need to be painted in order to avoid corrosion. Usually electrostatic painting is used on industrial scale, which requires the brake pads to be conductive. NAO brake pads (and especially Cu-free NAO brake pads) are rather insulating, and therefore difficult to paint. In this presentation we’ll show how special carbon powders can increase the electrical conductivity and therefore allow easy painting of brake pads. Based on these investigations, a new copper-free NAO formulation has been developed.
2016-09-18
Technical Paper
2016-01-1914
Pavlina Peikertova, Miroslava Kuricova, Alena Kazimirova, Jana Tulinska, Magdalena Barancokova, Aurelia Liskova, Marta Staruchova, Mira Horvathova, Silvia Ilavska, Eva Jahnova, Michaela Szabova, Miroslav Vaculik, Jana Kukutschova, Karla Kucova, Maria Dusinska, Peter Filip
Particulate air pollution from road traffic currently represents significant environmental and health issue. Attention is also paid to the “non-exhaust pollution sources,” which includes brake wear debris. During each brake application, the airborne and nonairborne particles are emitted into the environment due to wear. High temperatures and pressures on the friction surfaces initiate chemical and morphological changes of the initial components of brake pads and rotating counterparts. Understanding of impact of matter released from brakes on health is vital. Numerous studies clearly demonstrated that particulate matter caused potential adverse effects related to cytotoxicity, oxidative stress, stimulation of proinflammatory factors, and mutagenicity on the cellular level. This paper compiles our main results in the field of genotoxicity, immunotoxicity, and aquatic toxicity of airborne brake wear particles.
2016-09-18
Technical Paper
2016-01-1918
Yusuke Aoki, Yasuyuki Kanehira, Yukio Nishizawa
Brake squeal is an uncomfortable noise that occurs while braking. So, it is an important issue for automobile quality to prevent brake products from squealing. Brake shims are widely used to reduce squeal occurrence rate. To quantify the anti-squeal effect of shims, loss factor has been measured with a bending mode tester, instead of repeating many dynamometer tests. However, there are cases where measurement results have less correlation to actual squeal suppression rate. Therefore, we have to evaluate the anti-squeal effect by dynamometer or on an actual car until the best shim can be selected. In this work, we focused on the differences between measurement conditions and actual braking conditions of shims to obtain a good correlation. The bending mode tester measures loss factor under pressure-free condition even though shims are compressed by pistons or cylinders towards the backplate of the pad.
2016-09-18
Technical Paper
2016-01-1921
Yusuke Sunagawa, Tsuyoshi Kondo
Brake squeal noise is generally classified into two vibration modes of disc. One is called “out-of plane mode” which vibrates in disc’s out-of-plane direction. The other is “In-plane mode” which vibrates in disc’s in-plane direction, it means the disc is contracted partially or is extended. There are few “In-plane noise” analysis reports from Disc pad standpoint, so it has been unclear how disc pad contributes to “In-plane mode” until now. This paper confirms that we successfully analyzed direct pad vibration mode by laser scanning under in-plane mode condition. Based on these results, we assume that pad stiffness affected in-plane mode and carried out validation tests.
Viewing 1 to 30 of 7987