Display:

Results

Viewing 1 to 30 of 2721
2017-03-28
Journal Article
2017-01-0437
Bin Li, Subhash Rakheja
Abstract In this paper, a gain-scheduling optimal control approach is proposed to enhance yaw stability of articulated commercial vehicles through active braking of the proper wheel(s). For this purpose, an optimal feedback control is used to design a family of yaw moment controllers considering a broad range of vehicle velocities. The yaw moment controller is designed such that the instantaneous tractor yaw rate and articulation angle responses are forced to track the target values at each specific vehicle velocity. A gain scheduling mechanism is subsequently constructed via interpolations among the controllers. Furthermore, yaw moments derived from the proposed controller are realized by braking torque distribution among the appropriate wheels. The effectiveness of the proposed yaw stability control scheme is evaluated through software-in-the-loop (SIL) co-simulations involving Matlab/Simulink and TruckSim under lane change maneuvers.
2017-03-28
Technical Paper
2017-01-0436
Tianjun Zhu, Bin Li
Abstract A new extended planar model for multi-axle articulated vehicle with nonlinear tire model is presented. This nonlinear multi-axle articulated vehicle model is specifically intended for improving the model performance in operating regimes where tire lateral force is near the point of saturation, and it has the potential to extend the specific axles model to any representative configuration of articulated vehicle model. At the same time, the extended nonlinear vehicle model can reduce the model's sensitivity to the tire cornering coefficients. Firstly, a nonlinear tire model is used in conjunction with the 6-axle planar articulated vehicle model to extend the ranges of the original linear model into the nonlinear regimes of operation. Secondly, the performance analysis of proposed nonlinear vehicle model is verified through the double lane change maneuver on different road adhesion coefficients using TruckSim software.
2017-03-28
Technical Paper
2017-01-0479
Soichi Hareyama, Ken-ichi Manabe, Makoto Nakashima, Takayuki Shimodaira, Akio Hoshi
Abstract This investigation describes a method for estimating the absolute lock effect in bolted joint. Observation results of loosening phenomenon in industrial vehicle are analyzed for the linear relation by the proposed regression formula. Based on the relation, in early stages of the development test, the rate of clamping force decrease can be estimated accurately after prolonged operation by measuring the clamping force behavior. The tendency to decrease is observed about the depression type and working load type loosening. For evaluation design bases, the residual clamping force estimation chart is established. The L-N (Loosening Lifetime - Number of Cycles to Loosening N) diagram is proposed for the loosening lifetime prediction for working load type loosening also. Using the loosening damage (cumulative decrease of clamping force) and L-N diagram, the lifetime to loosening failure can be predicted accurately for the locking device and method as an absolute evaluation.
2017-03-28
Journal Article
2017-01-0153
Dipankar Sahoo, Adam Kotrba, Tom Steiner, Greg Swift
Abstract Nearly a third of the fuel energy is wasted through the exhaust of a vehicle. An efficient waste heat recovery process will undoubtedly lead to improved fuel efficiency and reduced greenhouse gas (GHG) emissions. Currently, there are multiple waste heat recovery technologies that are being investigated in the auto industry. One innovative waste heat recovery approach uses Thermoacoustic Converter (TAC) technology. Thermoacoustics is the field of physics related to the interaction of acoustic waves (sonic power) with heat flows. As in a heat engine, the TAC produces electric power where a temperature differential exists, which can be generated with engine exhaust (hot side) and coolant (cold side). Essentially, the TAC converts exhaust waste heat into electricity in two steps: 1) the exhaust waste heat is converted to acoustic energy (mechanical) and 2) the acoustic energy is converted to electrical energy.
2017-03-28
Technical Paper
2017-01-0261
Randolph Jones, Robert Marinier III, Frank Koss, Robert Bechtel, John A. Sauter
Abstract When evaluating new vehicle designs, modeling and simulation offer techniques to predict parameters such as maximum speed, fuel efficiency, turning radius, and the like. However, the measure of greatest interest is the likelihood of mission success. One approach to assessing the likelihood of mission success in simulation is to build behavior models, operating at the human decision-making level, that can execute realistic missions in simulation. This approach makes it possible to not only measure changes in mission success rates, but also to analyze the causes of mission failures. Layering behavior modeling and simulation on underlying models of equipment and components enables measurement of more conventional parameters such as time, fuel efficiency under realistic conditions, distance traveled, equipment used, and survivability.
2017-03-28
Technical Paper
2017-01-0260
Yuanying Wang, Heath Hofmann, Denise Rizzo, Scott Shurin
Abstract This paper presents a computationally-efficient model of heat convection due to air circulation produced by rotor motion in the air gap of an electric machine. The model calculates heat flux at the boundaries of the rotor and stator as a function of the rotor and stator temperatures and rotor speed. It is shown that, under certain assumptions, this mapping has the homogeneity property. This property, among others, is used to pose a structure for the proposed model. The coefficients of the model are then determined by fitting the model to the results of a commercial Computational Fluid Dynamics (CFD) simulation program. The accuracy of the new model is compared to the CFD results, shown an error of less than 0.3% over the studied operating range.
2017-03-28
Journal Article
2017-01-0269
Doohyun Kim, Jason Martz, Angela Violi
Abstract The ignition delay time for direct injection compression ignition engines is determined by complex physical and chemical phenomena that prepare the injected liquid fuel for gas phase ignition. In this work, Computational Fluid Dynamics (CFD) simulations of a reacting spray within a constant volume spray chamber are conducted to investigate the relative importance of liquid fuel physical properties and oxidation chemistry on the ignition delay time. The simulations use multi-component surrogates that emulate the physical and chemical properties of petroleum-derived (Jet-A) and natural-gas-derived (S-8) jet fuels. Results from numerical experiments isolating the fuel physical property and chemistry effects show that fuel chemistry is significantly more important to ignition delay than fuel physical properties under the conditions studied.
2017-03-28
Journal Article
2017-01-0346
Radwan Hazime, Thomas Seifert, Jeremy Kessens, Frank Ju
Abstract A complete thermomechanical fatigue (TMF) life prediction methodology is developed for predicting the TMF life of cast iron cylinder heads for efficient heavy duty internal combustion engines. The methodology uses transient temperature fields as thermal loads for the non-linear structural finite-element analysis (FEA). To obtain reliable stress and strain histories in the FEA for cast iron materials, a time and temperature dependent plasticity model which accounts for viscous effects, non-linear kinematic hardening and tension-compression asymmetry is required. For this purpose a unified elasto-viscoplastic Chaboche model coupled with damage is developed and implemented as a user material model (USERMAT) in the general purpose FEA program ANSYS. In addition, the mechanism-based DTMF model for TMF life prediction developed in Part I of the paper is extended to three-dimensional stress states under transient non-proportional loading conditions.
2017-03-28
Technical Paper
2017-01-1035
Xingyu Xue, John Rutledge
Abstract Diesel engine downsizing aimed at reducing fuel consumption while meeting stringent exhaust emissions regulations is currently in high demand. The boost system architecture plays an essential role in providing adequate air flow rate for diesel fuel combustion while avoiding impaired transient response of the downsized engine. Electric Turbocharger Assist (ETA) technology integrates an electric motor/generator with the turbocharger to provide electrical power to assist compressor work or to electrically recover excess turbine power. Additionally, a variable geometry turbine (VGT) is able to bring an extra degree of freedom for the boost system optimization. The electrically-assisted turbocharger, coupled with VGT, provides an illuminating opportunity to increase the diesel engine power density and enhance the downsized engine transient response.
2017-03-28
Technical Paper
2017-01-0781
Philip Zoldak, Jeffrey Naber
Abstract The increased availability of natural gas (NG) in the United States (US) and its relatively low cost versus diesel fuel has increased interest in the conversion of medium duty (MD) and heavy duty (HD) engines to NG fueled combustion systems. The aim for development for these NG engines is to realize fuel cost savings and increase operating range while reduce harmful emissions and maintaining durability. Traditionally, port-fuel injection (PFI) or premixed NG spark-ignited (SI) combustion systems have been used for light duty LD, and MD engines with widespread use in the US and Europe [1]. However, this technology exhibits poor thermal efficiency and is load limited due to knock phenomenon that has prohibited its use for HD engines. Spark Ignited Direct Injection (SIDI) can be used to create a partially stratified combustion (PSC) mixture of NG and air during the compression stroke.
2017-03-28
Technical Paper
2017-01-0894
Nishant Singh
Abstract Improving fuel economy has been a key focus across the automotive industry for several years if not decades. For heavy duty commercial vehicles, the benefits from minor gains in fuel economy can lead to significant savings for fleets as well as owners and operators. Additionally, the regulations require vehicles to meet certain GHG standards which closely translate to vehicle fuel economy. For current state of the art fuel economy technologies, incremental gains are so miniscule that measurements on the vehicle are inadequate to quantify the benefits. Engineers are challenged with high level of variability to make informed decisions. In such cases, highly controlled tests on Engine and Powertrain dynamometers are used, however, there is an associated variability even with these tests due to factors such as part to part differences, deterioration, fuel blends and quality, dyno control capabilities and so on.
2017-03-28
Technical Paper
2017-01-0957
Ian Smith, Thomas Briggs, Christopher Sharp, Cynthia Webb
Abstract It is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards of 0.20 g/bhp-hr, the National Ambient Air Quality Standards (NAAQS) requirements for ambient ozone will not be met. It is expected that further reductions in NOX emissions from the heavy-duty fleet will be required to achieve compliance with the ambient ozone requirement. To study the feasibility of further reductions, the California Air Resources Board (CARB) funded a research program to demonstrate the potential to reach 0.02 g/bhp-hr NOX emissions. This paper details the work executed to achieve this goal on the heavy-duty Federal Test Procedure (FTP) with a heavy-duty natural gas engine equipped with a three-way catalyst. A Cummins ISX-12G natural gas engine was modified and coupled with an advanced catalyst system.
2017-03-28
Journal Article
2017-01-0901
Alex Pink, Adam Ragatz, Lijuan Wang, Eric Wood, Jeffrey Gonder
Abstract Vehicles continuously report real-time fuel consumption estimates over their data bus, known as the controller area network (CAN). However, the accuracy of these fueling estimates is uncertain to researchers who collect these data from any given vehicle. To assess the accuracy of these estimates, CAN-reported fuel consumption data are compared against fuel measurements from precise instrumentation. The data analyzed consisted of eight medium/heavy-duty vehicles and two medium-duty engines. Varying discrepancies between CAN fueling rates and the more accurate measurements emerged but without a vehicular trend-for some vehicles the CAN under-reported fuel consumption and for others the CAN over-reported fuel consumption. Furthermore, a qualitative real-time analysis revealed that the operating conditions under which these fueling discrepancies arose varied among vehicles.
2017-03-28
Journal Article
2017-01-0342
Benjamin Möller, Alessio Tomasella, Rainer Wagener, Tobias Melz
Abstract The cyclic material behavior is investigated, by strain-controlled testing, of 8 mm thick sheet metal specimens and butt joints, manufactured by manual gas metal arc welding (GMAW). The materials used in this investigation are the high-strength structural steels S960QL, S960M and S1100QL. Trilinear strain-life curves and cyclic stress-strain curves have been derived for the base material and the as-welded state of each steel grade. Due to the cyclic softening in combination with a high load level at the initial load cycle, the cyclic stress-strain curve cannot be applied directly for a fatigue assessment of welded structures. Therefore, the transient effects have been analyzed in order to describe the time-variant material behavior in a more detailed manner. This should be the basis for the enhancement of the fatigue life estimation.
2017-03-28
Journal Article
2017-01-0404
Anatoliy Dubrovskiy, Sergei Aliukov, Sergei Dubrovskiy, Alexander Alyukov
Abstract Currently, a group of scientists consisting of six doctors of technical sciences, professors of South Ural State University (Chelyabinsk, Russia) has completed a cycle of scientific research for creation of adaptive suspensions of vehicles. We have developed design solutions of the suspensions. These solutions allow us to adjust the performance of the suspensions directly during movement of a vehicle, depending on road conditions - either in automatic mode or in manual mode. We have developed, researched, designed, manufactured, and tested experimentally the following main components of the adaptive suspensions of vehicles: 1) blocked adaptive dampers and 2) elastic elements with nonlinear characteristic and with improved performance.
2017-03-28
Journal Article
2017-01-0425
Hong Wang, Yanjun Huang, Chen Lv, Amir Khajepour
Abstract Energy management strategies greatly influence the power performance and fuel economy of series hybrid electric tracked bulldozers. In this paper, we present a procedure for the design of a power management strategy by defining a cost function, in this case, the minimization of the vehicle’s fuel consumption over a driving cycle. To explore the fuel-saving potential of a series hybrid electric tracked bulldozer, a dynamic programming (DP) algorithm is utilized to determine the optimal control actions for a series hybrid powertrain, and this can be the benchmark for the assessment of other control strategies. The results from comparing the DP strategy and the rule-based control strategy indicate that this procedure results in approximately a 7% improvement in fuel economy.
2017-03-28
Technical Paper
2017-01-0428
Tianqi Lv, Yan Wang, Xingxing Feng, Yunqing Zhang
Abstract Steering returnability is an important index for evaluating vehicle handling performance. A systematic method is presented in this paper to reduce the high yaw rate residue and the steering response time for a light duty truck in the steering return test. The vehicle multibody model is established in ADAMS, which takes into consideration of the frictional loss torque and hydraulically assisted steering property in the steering mechanism, since the friction, which exists in steering column, spherical joint, steering universal joint, and steering gear, plays an important role in vehicle returnability performance. The accuracy of the vehicle model is validated by road test and the key parameters are determined by executing the sensitivity analysis, which shows the effect of each design parameter upon returnability performance.
2017-03-28
Journal Article
2017-01-0419
Yuliang Yang, Yu Yang, Ying Sun, Jian Zeng, Yunquan Zhang
Abstract In addition to ride comfort, handling stability and other conventional vehicle performances, we should also focus on other aspects of performance to a center axle trailer combination, such as the maximum stable side-inclination, the anti-rolling stability, the lateral stability and so on. Based on the finite element method, a rigid-flexible coupling model for the truck combination was built and analyzed in the multi-body environment (ADAMS), in which the key components of the chassis and cab suspension were treated as flexible bodies. A series of simulations were carried out to evaluate the lateral stability of the center axle trailer in accordance with the relevant regulations of the vehicle. The influence of design variables on the lateral stability was studied by an experiment. Furthermore, in order to improve the lateral stability of the trailer combination, the optimal design was obtained by the co-simulation of the ADAMS/Car, iSIGHT and Matlab.
2017-03-28
Journal Article
2017-01-0237
Jonas Biteus, Tony Lindgren
Abstract Maintenance planning of trucks at Scania have previously been done using static cyclic plans with fixed sets of maintenance tasks, determined by mileage, calendar time, and some data driven physical models. Flexible maintenance have improved the maintenance program with the addition of general data driven expert rules and the ability to move sub-sets of maintenance tasks between maintenance occasions. Meanwhile, successful modelling with machine learning on big data, automatic planning using constraint programming, and route optimization are hinting on the ability to achieve even higher fleet utilization by further improvements of the flexible maintenance. The maintenance program have therefore been partitioned into its smallest parts and formulated as individual constraint rules. The overall goal is to maximize the utilization of a fleet, i.e. maximize the ability to perform transport assignments, with respect to maintenance.
2017-03-28
Technical Paper
2017-01-0080
Qilu Wang, Bo Yang, Gangfeng Tan, Shengguang Xiong, XiaoXiao Zhou
Abstract Mountain road winding and bumpy, traffic accidents caused by speeding frequently happened, mainly concentrated on curves. The present curve warning system research are based on Charge-coupled Device, but the existing obstacles, weather , driving at night and road conditions directly affect the accuracy and applicability. The research is of predictability to identify the curves based on the geographic information and can told the driver road information and safety speed ahead of the road according to the commercial vehicle characteristic of load, and the characteristics of the mass center to reduce the incidence of accidents. In this paper, the main research contents include: to estimate forward bend curvature through the node classification method based on the digital map.
2017-03-28
Technical Paper
2017-01-0090
Ondrej Santin, Jaroslav Beran, Jaroslav Pekar, John Michelini, Junbo Jing, Steve Szwabowski, Dimitar Filev
Abstract Conventional cruise control systems in automotive applications are usually designed to maintain the constant speed of the vehicle based on the desired set-point. It has been shown that fuel economy while in cruise control can be improved using advanced control methods namely adopting the Model Predictive Control (MPC) technology utilizing the road grade preview information and allowance of the vehicle speed variation. This paper is focused on the extension of the Adaptive Nonlinear Model Predictive Controller (ANLMPC) reported earlier by application to the trailer tow use-case. As the connected trailer changes the aerodynamic drag and the overall vehicle mass, it may lead to the undesired downshifts for the conventional cruise controller introducing the fuel economy losses. In this work, the ANLMPC concept is extended to avoid downshifts by translating the downshift conditions to the constraints of the underlying optimization problem to be solved.
2017-03-28
Technical Paper
2017-01-0137
Akira Ando, Koichi Hamashima, Shinji Kato, Noriyuki Tomita, Takahiro Uejima
Abstract In respect to the present large refrigerator trucks, sub-engine type is the main product, but the basic structure does not change greatly since the introduction for around 50 years. A sub-engine type uses an industrial engine to drive the compressor, and the environmental correspondence such as the fuel consumption, the emission is late remarkably. In addition, most of trucks carry the truck equipment including the refrigerator which consumes fuel about 20% of whole vehicle. Focusing on this point, the following are the reports about the system development plan for fuel consumption reduction of the large size refrigerator truck. New concept is to utilize electrical power from HV system to power the electric-driven refrigerator. We have developed a fully electric-driven refrigerator system, which uses regenerated energy that is dedicated for our refrigerator system.
2017-03-28
Journal Article
2017-01-0133
Bin Xu, Adamu Yebi, Simona Onori, Zoran Filipi, Xiaobing Liu, John Shutty, Paul Anschel, Mark Hoffman
Abstract This paper presents the transient power optimization of an organic Rankine cycle waste heat recovery (ORC-WHR) system operating on a heavy-duty diesel (HDD). The optimization process is carried on an experimentally validated, physics-based, high fidelity ORC-WHR model, which consists of parallel tail pipe and EGR evaporators, a high pressure working fluid pump, a turbine expander, etc. Three different ORC-WHR mixed vapor temperature (MVT) operational strategies are evaluated to optimize the ORC system net power: (i) constant MVT; (ii) constant superheat temperature; (iii) fuzzy logic superheat temperature based on waste power level. Transient engine conditions are considered in the optimization. Optimization results reveal that adaptation of the vapor temperature setpoint based on evaporation pressure strategy (ii) provides 1.1% mean net power (MNP) improvement relative to a fixed setpoint strategy (i).
2017-03-28
Journal Article
2017-01-0695
Ezio Spessa, Stefano D'Ambrosio, Daniele Iemmolo, Alessandro Mancarella, Roberto Vitolo, Gilles Hardy
Abstract In the present work, different combustion control strategies have been experimentally tested in a heavy-duty 3.0 L Euro VI diesel engine. In particular, closed-loop pressure-based and open-loop model-based techniques, able to perform a real-time control of the center of combustion (MFB50), have been compared with the standard map-based engine calibration in order to highlight their potentialities. In the pressure-based technique, the instantaneous measurement of in-cylinder pressure signal is performed by a pressure transducer, from which the MFB50 can be directly calculated and the start of the injection of the main pulse (SOImain) is set in a closed-loop control to reach the MFB50 target, while the model-based approach exploits a heat release rate predictive model to estimate the MFB50 value and sets the corresponding SOImain in an open-loop control. The experimental campaign involved both steady-state and transient tests.
2017-03-28
Journal Article
2017-01-1510
Kisun Song, Kyung Hak Choo, Dimitri Mavris
Abstract In early phases of conceptual design stages for developing a new car in the modern automobile industry, the lack of systematic methodology to efficiently converge to an agreement between the aesthetics and aerodynamic performance tremendously increases budget and time. During these procedures, one of the most important tasks is to create geometric information which is versatilely morphable upon the demands of both of stylists and engineers. In this perspective, this paper proposes a Spline-based Modeling Algorithm (SMA) to implement into performing aerodynamic design optimization research based on CFD analysis. Once a 3-perspective schematic of a car is given, SMA regresses the backbone boundary lines by using optimum polynomial interpolation methods with the best goodness of fit, eventually reconstructing the 3D shape by linearly interpolating from the extracted boundaries minimizing loss of important geometric features.
2017-03-28
Technical Paper
2017-01-1503
Jared Johan Engelbrecht, Tony Russell Martin, Piyush M. Gulve, Nagarjun Chandrashekar, Amol Dwivedi, Peter Thomas Tkacik, Zachary Merrill
Abstract Most commercial heavy-duty truck trailers are equipped with either a two sensor, one modulator (2S1M) or four sensors, two modulator (4S2M) anti-lock braking system (ABS). Previous research has been performed comparing the performance of different ABS modules, in areas such as longitudinal and lateral stability, and stopping distance. This study focuses on relating ABS module type and wheel speed sensor placement to trailer wheel lock-up and subsequent impact to tire wear for tandem axle trailers with the Hendrickson air-ride suspension. Prior to tire wear inspection, functionality of the ABS system was testing using an ABS scan tool communicating with the SAE J1587 plug access port on the trailer. Observations were documented on trailers using the 2S1M system with the wheel speed sensor placed on either the front or rear axle of a tandem pair.
2017-03-28
Technical Paper
2017-01-1490
Silvia Faria Iombriller
Abstract The air suspension development and its applications have becoming increasingly relevant for commercial vehicles to provide dynamic ride comfort to driver and reduce the load impact onto driver and or cargo. This paper shows the analysis and application of an air suspension system for commercial tractor vehicles and its dynamic influence. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension´s stiffness under different conditions of usage, laden and unladed. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions.
2017-03-28
Journal Article
2017-01-1554
Ajith Jogi, Sujatha Chandramohan
Abstract Over the years, commercial vehicles, especially tractor-semitrailer combinations have become larger and longer. With the increasing demand for their accessibility in remote locations, these vehicles face the problem of off-tracking, which is the ensuing difference in path radii between the front and rear axles of a vehicle as it maneuvers a turn. Apart from steering the rear axle of the semitrailer, one of the feasible ways of mitigating off-tracking is to shift the fifth wheel coupling rearwards. However, this is limited by the distribution of the semitrailer’s load between the two axles of the tractor; any rearward shift of the fifth wheel coupling results in the reduction of the total static load on the tractor’s front axle and hence available traction. This may in turn lead to directional instability of the vehicle. In the present work, a new model of the fifth wheel coupling is proposed which the authors call Split fifth wheel coupling (SFWC).
2017-03-28
Technical Paper
2017-01-1538
Jiaye Gan, Longxian Li, Gecheng Zha, Craig Czlapinski
Abstract This paper conducts numerical simulation and wind tunnel testing to demonstrate the passive flow control jet boat tail (JBT) drag reduction technique for a heavy duty truck rear view mirror. The JBT passive flow control technique is to introduce a flow jet by opening an inlet in the front of a bluff body, accelerate the jet via a converging duct and eject the jet at an angle toward the center of the base surface. The high speed jet flow entrains the free stream flow to energize the base flow, increase the base pressure, reduces the wake size, and thus reduce the drag. A baseline heavy duty truck rear view mirror is used as reference. The mirror is then redesigned to include the JBT feature without violating any of the variable mirror position geometric constraints and internal control system volume requirement. The wind tunnel testing was conducted at various flow speed and yaw angles.
2017-03-28
Technical Paper
2017-01-1531
Keiichi Taniguchi, Akiyoshi Shibata, Mikako Murakami, Munehiko Oshima
Abstract This paper describes a study of drag reduction devices for production pick-up trucks with a body-on-frame structure using full-scale wind tunnel testing and Computational Fluid Dynamics (CFD) simulations. First, the flow structure around a pick-up truck was investigated and studied, focusing in particular on the flow structure between the cabin and tailgate. It was found that the flow structure around the tailgate was closely related to aerodynamic drag. A low drag flow structure was found by flow analysis, and the separation angle at the roof end was identified as being important to achieve the flow structure. While proceeding with the development of a new production model, a technical issue of the flow structure involving sensitivity to the vehicle velocity was identified in connection with optimization of the roof end shape. (1)A tailgate spoiler was examined for solving this issue.
Viewing 1 to 30 of 2721

Filter