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2016-04-05
Technical Paper
2016-01-0447
Manfred Baecker, Axel Gallrein, Francesco Calabrese, Remco Mansvelders
A sudden pressure loss can lead to an instability of the car. This instability can lead - without aid of systems such as e.g. Electronic Stability Control (ESC) - to an emergency situation, possibly resulting in an accident. But also with an ESC system such a situation is an unusual application case, because the vehicle system (car+tires) properties change very rapidly, resulting in a highly dynamic response of the system and moreover to a fuzzy and unclear description of the vehicle system. From this point of view, a proper validation and verification of an ESC system for such an application seems to have a big safety relevance. The authors have set up a simulation case to simulate a sudden tire inflation pressure loss and its consequences to the car stability. Using this simulation setup enables a CAE engineer to pre-develop ESC systems and/or to validate and test these systems for a realistic and relevant use case.
2016-04-05
Technical Paper
2016-01-0446
Chen liang, Guolin Wang, Zhou Zheng
A three-dimensional finite element model of radial tire 205/55R16,established by ABAQUS software,is used to simulate tire force and moment properties. Drum tests are designed to validate the simulation model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented, based on string balance contour theory, which simplifies the belts pressure share ratio as trapezium. And a program for calculating tire’s contour is compiled. Different tire contours are designed according to different belt pressure share ratios. One of the contours is selected according to the positive affect to cornering stiffness. Compare the selected newly designed tire with the original one, it is found that the newly designed tire’s contact area, longitudinal stiffness,lateral stiffness,camber stiffness and cornering stiffness increase while its radial stiffness decreases.
2016-04-05
Technical Paper
2016-01-0442
Xing Xu, Zou Nannan
Interconnected air suspension system can change vehicle’s operation characteristics by exchanging gas of air springs. In this paper, we analyze the structure and working principle of interconnected air suspension based on thermodynamics and vehicle dynamics. Then air suspension’s mathematical model including interconnected characteristics is established to study gas exchange principle of air suspension system. Interconnected pipeline parameters and excitation phase differences’ influence on characteristics of air suspension system in whole vehicle are calculated and analyzed. Simulation results show that the stiffness of air suspension is reduced when air springs of suspension system interconnected, as well as it decreases gradually with the increase of interconnected pipeline diameter; the stiffness of air springs is minimum if the excitation phase difference of both sides of air springs is 180 degree.
2016-04-05
Technical Paper
2016-01-0810
Massimo Cardone, Ezio Mancaruso, Renato Marialto, Luigi Sequino, Bianca Maria Vaglieco
The interest of the vehicle producers in fulfill the emission legislations without adopting after treatment systems is driving to the use of non-conventional energy sources for modern engines. A previous test campaign on the use of blends of diesel and propane in a CI engine has pointed out the potential of this non-conventional fuel for diesel engines. The soft adaptation of the common rail injection system and the potential benefits, in terms of engine consumption and pollutant emissions, encourage the use of propane/diesel blends if an optimization of the injection strategies is performed. In this work, the performances of a propane/diesel preformed mixture in a research diesel engine have been investigated. The injection strategies of Euro 5 calibration have been used as reference for the develop of optimized strategies. The aim of the optimization process was to gather the same engine power output and reduce the pollutant emissions.
2016-04-05
Technical Paper
2016-01-0448
Yuliang Yang, Yu Yang, Ying Sun, Zhihong Dong, Yunquan zhang
To improve the vehicle NVH performance, reduce the vibration of the exhaust system, average driving DOF displacement (ADDOFD) and dynamic analysis are used to optimize hanger locations. Based on the finite element analysis and rigid-flexible coupling analysis, exhaust system analysis model was established. According to the finite element model of the exhaust system, the free-free modal analysis is carried out, and the position of the hanging point of the exhaust system is optimized by using the ADDOFD method. Furthermore, through the dynamics analysis, the force of each hanger to the body is calculated by the dynamic analysis, then verify the rationality of the hanging position. The combination of the two methods can effectively determine the better NVH performance of the exhaust system with hanger locations in the earlier vehicle development process.
2016-04-05
Technical Paper
2016-01-0575
Konstantinos Siokos, Rohit Koli, Robert Prucka, Jason Schwanke, Shyam Jade
Low pressure (LP) and cooled EGR systems are capable of increasing fuel efficiency of turbocharged gasoline engines, however they introduce control challenges. Accurate exhaust pressure modeling is of particular importance for real-time feedforward control of these EGR systems since they operate under low pressure differentials. To provide a solution that does not depend on physical sensors in the exhaust and also does not require extensive calibration, a coupled temperature and pressure physics-based model is proposed. The exhaust manifold is split into two different lumped sections based on flow conditions in order to calculate the turbine-outlet pressure, which is the driving force for LP-EGR. The temperature model uses the turbine-outlet temperature as an input, which is known through existing engine control models, to determine heat transfer losses through the exhaust.
2016-04-05
Technical Paper
2016-01-0441
Aref M. A. Soliman
ABSTRACT An active suspension system has better performance than a passive suspension. However, it requires a significant amount of energy and is constructed from high cost components. To solve the problem of the power required, a switchable damper suspension system has been studied. In this paper, control strategies for the switchable damper suspension system and passive are compared in terms of their relative ride performance capabilities. Practical limitations involving switching time delay and threshold delay values are modeled and their effect on the ride performance are evaluated. The four setting switchable damper is compared with the two and three setting switchable dampers. The control strategies are used to maintain suspension working space level within design limit and to minimize body acceleration level. The results showed that the four setting switchable damper gives better ride improvements compared with the two and three setting switchable dampers.
2016-04-05
Technical Paper
2016-01-1277
Monis Alam, Ashish Jaiswal, Jatin Agarwal, Ketan Yadav, Naveen Kumar
Gasoline has become a major fuel in transportation, its good calorific value and high volatility have made it suitable for use in different injection methods. The drastic increase in use of carbon based fuel has led to increase in harmful emissions, this resulted in implementation of stricter emissions norms. These harmful emissions include carbon monoxide and NOx. To meet the new norms and reduce the harmful emissions better techniques has to be implemented to achieve better combustion of gasoline. One such way of doing this is by enriching gasoline with hydrogen, due to its low activation energy and high calorific value the high energy released from hydrogen can be used to achieve complete combustion of gasoline fuel. There are certain drawbacks to the use of hydrogen in spark ignition engine, knocking and overheating of engine parts are the major of them.
2016-04-05
Technical Paper
2016-01-0470
Wei Chen, Zhe Sun, Jun Zheng, Liang Pan, Xurong Yi
The muti-body dynamic modeling and simulation was widely used in the vehicle dynamics developing process. However, it is difficult to get the parameters of the vehicle in the early stage, especially for the hardpoints. This paper analyzed the relationship of the chassis suspension, steering systems and wheels, and proposed a new vehicle dynamic modeling method using MSC.ADAMS. A four-wheeled vehicle can be approximated as a vehicle consisting of four wheels and body. The wheels and the body are connected by rods, spring and shock absorber. Firstly, the modeling method analyzes the relationship between the suspension and the steering and wheels. Secondly, constraint equations are established in Adams/View to represent the movement of the wheel. Then, characteristic parameters obtained from the test are input for modeling and simulation, without considering the concrete structure of the suspension, hard points, etc.
2016-04-05
Technical Paper
2016-01-0464
Lingyang Li, Wei Wu, Ji Chen, Jianpeng shi, Xicheng Wang, Liuhua Qian
In order to expand the product design and development capabilities of Electric Power Steering (EPS) system, a passenger car's simulation model integrated with EPS system model will be made, and do some analytical investigation in this paper. Through simplifying the architecture model of EPS system, the mathematical equation expressions of steering wheel and column, worm gear reducer, rack and pinion, steer-wheels, brushed DC electrical motor, and ECU assistance and compensation laws will be described. A number of tests on the EPS full system and subsystems and components will be executed. The tests' results will be used as the input parameters of the model, and then be used for model validations. After that, the EPS system model will be created. Since the most important part of control logic strategy is the top secret of steering assembly supplier and it could't be provided to OEM in details or not even a black-box model directly.
2016-04-05
Technical Paper
2016-01-0449
Xian Xu, Wei Chen, Yuan cao, Yingxiong Zhang, Hu Guo
The stiffness of the frame has a great influence on the ride comfort of the heavy truck. Reducing frame thickness was proved to be unacceptable in terms of ride comfort, which is verified by the testing results. The truck frame was reinforced in order to improve the ride comfort. The modal analyse showed that the pitch frequency of the vehicle has increased 0.5 Hz and the frequency response has decreased by 20%. A detailed model including a flex frame, chassis suspension, cab suspension, driveline, etc., was built by MSC.ADAMS to research the influence of frame stiffness on the heavy truck ride comfort. The Simulation results showed that the ride comfort can be improved by reinforce the frame, and the ride comfort can be improved by 5%~10%. The results of this study need to be further examined through filed testing.
2016-04-05
Technical Paper
2016-01-1313
Brian Pinkelman, Woo-Keun Song
Most methods of vibration analysis focus on measuring the level of vibration. Some methods like ISO-2631 weigh vibration level based on human sensitivity of location, direction, and frequency. Sound can be similarly measured by sound pressure level in dB. It may also be weighted to human frequency sensitivity such as dBA but sound and noise analysis has expanded to measure sound quality. The characteristic and the nature of the sound are studied. As an example equal or near equal sound levels can provide different experiences to the listener. Such was the question for vibration, “can vibration quality be assessed just as sound quality is assessed?” Early on in our studies vibration sensory experts found a difference in 4 seats yet we could find no objective measurement of vibration level that could reliable confirm the sensory experience. Yet these particular experiences correlated to certain verbal descriptors including smoothness or roughness.
2016-04-05
Technical Paper
2016-01-0453
Yingxiao Xu, Xuexun Guo, Gangfeng Tan, Jiawei Li, Yongchi Zhou, Yangjie Ji, LiWen Yu
Eddy current retarder(ECR) shares a large domestic market of auxiliary brakes in China, but shortcomings of the short continuous braking time and the high additional energy consumption are also obvious. The propose of combined braking partakes the braking torque of ECR, while the existing serial-parallel braking strategy can't balance the relationship between the braking stability and the efficiency of energy recovery well. This research puts forward an energy management strategy of combined braking system which aims to maximize energy recovery while ensure the brake stability. The motor speed, braking request and the state of charge(SoC) of storage module are analyzed synthetically to calculate the reasonable braking torque distribution proportion. And the recovered energy is priority for braking unit to reduce the additional energy consumption in this strategy.
2016-04-05
Technical Paper
2016-01-1084
Chendi Sun, Vinson Jia
With rigorous fuel consumption regulation and emission law implemented, accuracy requirement of design and measurement signal is increasing, it becomes more and more indispensable to consider the influence on pressure loss and flow behavior coming from the incrementally loaded dust on filter element of Air Intake System (AIS). Dust is composed of many different sizes of particles, and studies shows that these different sizes of particles have very distinct influence on pressure loss of filter elements, which makes dust a challenge to model in Computational Fluid Dynamics (CFD) simulation. In order to precisely simulate pressure loss behavior of dust loaded filter element, a methodology for 3-D CFD dust loading simulation is developed, where the influence of particles sizes on pressure loss of filter element are taken into consideration by introducing a pressure loss weighting factors.
2016-04-05
Technical Paper
2016-01-0439
Tianqi Lv, Peijun Xu, Yunqing Zhang
The powertrain mounting system plays a very important role in controlling the NVH performance of a vehicle. The simulation analysis of powertrain mounting system adopts the linear rotation approximation model based on the premise of powertrain with small rotation angle assumption, but in some extreme loading conditions, powertrain will happen larger angle rotation, so the approximate model calculation results will be inaccurate, the calculation results of inaccurate is likely to cause powertrain interferes with the surrounding parts. This paper build a calculation model of powertrain rigid body dynamics with consideration nonlinear stiffness of the mount, and through the Newton-Raphson's iterative algorithm to solve the displacement and loads of mount system.
2016-04-05
Technical Paper
2016-01-0899
Takashi Hoshino, Farrukh Qureshi, Nicholas Virostko, Elizabeth Schiferl, Ananda Gajanayake, Motoji Hiroki, Tomoya Higuchi, Keita Ishizaki
The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in hardware by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate chemistry in. Axle lubricants have a significant impact on fuel economy. Importantly, they can be tailored to deliver maximum operation efficiency over either specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are commonly known to be having a trade-off relationship.
2016-04-05
Technical Paper
2016-01-0451
Fu Wenkui, Liu Ligang, Shu Jin, Wang Dawei, Xu Long
Virtual Road Load Data Acquisition(vRLDA) is to replace traditional Road Load Data Acquisition(RLDA) thus become the important method to obtain the load for the fatigue analysis of the vehicle components. This paper makes a simulation analysis for pothole based on Adams/Car, a typical loadcase in road load data acquisition. Flex-body is adopted in the full vehicle model in order to improve the simulation accuracy. Flexible ring tire model, ftire, is used for the benefit of valid in higher frequency domain. The result shows that simulation result correlated well in wheel center travel and load of tire and suspension parts. Consequently, it is available to predict the max effective jounce travel and body max load in the early phase of vehicle development thus decrease the potential risk in the late phase and the total research cost. The vRLDA is also proven as a reliable and effective method to obtain the load.
2016-04-05
Technical Paper
2016-01-0450
Somnath Sen, Paulson Parayil
In order to ensure a comfortable space inside the cabin, it is very essential to design an efficient heating, ventilating and air-conditioning (HVAC) system which can deliver uniform temperature distribution at its mouth. There are several factors which impact on uniformity of temperature distribution. Airflow distribution is one of the key parameter in deciding the effectiveness of temperature distribution. Kinematics links and linkage system typically termed as ‘kinematics mechanism’ is one of the critical sub-systems which greatly affects the airflow distribution. It is not the temperature uniformity but also the HVAC temperature linearity also depends on airflow distribution. Hence the design of link mechanism is incomparably of paramount importance to achieve the desired level of airflow distribution at HVAC mouths. The present paper describes the design methodology of automotive HVAC linkage system.
2016-04-05
Technical Paper
2016-01-0445
Brian Paul Wiegand
Evaluation of the performance potential of an automotive conceptual design requires some initial quantitative estimate of numerous relevant parameters. Such parameters include the vehicle mass properties, frontal and plan areas, aero drag and lift coefficients, available horsepower and torque, and various tire characteristics such as the rolling resistance... A number of rolling resistance models have been advanced since Robert William Thomson first patented the pneumatic rubber tire in 1845, most of them developed in the twentieth century. Most early models only crudely approximate tire rolling resistance behavior over a limited range of operation, while the latest models overcome those limitations but often at the expense of extreme complexity requiring significant computer resources.
2016-04-05
Technical Paper
2016-01-0646
Pablo Olmeda, Jaime Martin, Antonio Garcia, Diego Blanco, Alok Warey, Vicent Domenech
Regulated emissions and fuel consumption are the main constraints affecting engine design. Over the years, many techniques have been used with the aim of meeting these limitations. In particular, EGR has demonstrated to be a necessary solution to reduce NOx emissions, becoming a widely used technique in production diesel engines. However, its application has a direct effect on fuel consumption due to both the changes in the in-cylinder processes, affecting indicated efficiency, as well as air management. An analysis, based on the engine Global Energy Balance, is presented to thoroughly assess the behavior of a HSDI diesel engine under variable EGR conditions at different operating points. The tests have been carried out, while keeping combustion phasing and conditions at intake valve closing (IVC) fixed.
2016-04-05
Technical Paper
2016-01-0905
Robert J. Middleton, Omnaath Guptha Harihara Gupta, Han-Yuan Chang, George Lavoie, Jason Martz
This study evaluates powertrain technologies capable of reducing light duty vehicle fuel consumption for compliance with 2025 CAFE standards. In a companion paper, a fully integrated GT-Power engine model was used to evaluate the effectiveness of a plausible series of engine technologies, including valve train improvements such as dual cam phasing and discrete variable valve lift, and engine downsizing with turbocharging and cooled EGR. In this paper, those engine efficiency/performance results are used in a vehicle drive cycle simulation to estimate the impact of engine and transmission technology improvements on light duty vehicle fuel consumption over the EPA’s FTP and HWY test schedules. The model test vehicle is a midsized sedan based on the MY2012 Ford Fusion with constant test weight of 3625 lbs, with constant drag and rolling resistance characteristics.
2016-04-05
Technical Paper
2016-01-0463
Juan Sierra, Camilo Cruz, Luis Munoz, Santiago Avila, Elkin Espitia, Jaime Rodriguez
Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.
2016-04-05
Technical Paper
2016-01-0440
Li Jie, Wang Wenzhu, Gao Xiong, Zhang Zhenwei
The heavy truck often moves in a poor, long-distance and high-speed freight state environment, so drivers are easy to fatigue and goods are easily damaged. At the same time, compared to the passenger car, the ride comfort of heavy trucks has a lot of room for improvement. Therefore, the research on the ride comfort of heavy trucks becomes crucial.Based the elastic theory of Euler-Bernoulli beam with both free ends, a 6 DOF half rigid-elastic vibration model of the vertical dynamic response is developed, which is more suitable to the actual movement of heavy trucks. The DOFs include: vertical displacements of the body and each of two axles; the pitch displacement of the body; the first and second order bending displacements of the body. The root mean square values of body acceleration, dynamic deflections and relative dynamic loads act as evaluation index.
2016-04-05
Technical Paper
2016-01-0049
Jinwei Zhou, Roman Schmied, Alexander Sandalek, Helmut Kokal, Luigi del Re
The implementation of Advanced Driver Assistant Systems (ADAS) in production standard vehicles requires extensive test bench and field testing as the manufacturer has to guarantee for functionality and safety in all possible traffic environment situations. Especially field tests consume a lot of time and money which is the reason why methods that allow a reduction of field test hours obtain high attention. Virtual ADAS testing using a simulation environment provides great potential in reducing real world testing and therefore currently much effort is spent on the development of such tools. This work proposes a simulation and hardware-in-the-loop (HIL) framework, which helps to create a virtual test environment for ADAS based on real world test drives. The idea is to reproduce environmental conditions obtained on a test drive within a simulation environment.
2016-04-05
Technical Paper
2016-01-0051
Hongyu Zheng, Mingxin Zhao
Electric power steering, active front wheel steering and steer by wire systems can improve the steering portability at low speed and ameliorate the steering feeling at high speed, so as to enhance the handling stability of the vehicle. It can even perform an active steering intervention in dangerous working conditions to increase the active safety of automobile. However, the development of the electric steering system , which needs to test and modify repeatedly, involves the machinery, the controller hardware , control algorithm and many other aspects of designs. Now the development of the electric steering system is mainly based on the way that combines the test of the electric steering hardware-in-loop(HIL) test bench with real vehicle road test. But the real vehicle test with higher cost, long cycle and vulnerable to space weather have the potential safety problems at the beginning of the system development.
2016-04-05
Technical Paper
2016-01-1550
Ming Peng, Xuexun Guo, Junyi Zou, Chengcai Zhang
This paper presents a novel concept of the application of the hydraulic electromagnetic energy-regenerative shock absorber (HESA) into the commercial vehicle suspension system and the vehicle road performances are simulated by the evaluating indexes (e.g. the root-mean-square values of vertical acceleration of sprung mass, dynamic tire-ground contact force, suspension deflection and harvested power). Firstly, the configuration and working principle of the HESA are introduced. Then, the damping characteristics of the HESA and the seven-degrees-of-freedom vehicle dynamics were modeled respectively before derive the dynamic characteristics of a vehicle equipped with the HESA. The control current is fixed at 7A to match the similar damping effect of traditional linear damper on the basis of the energy conversion method of nonlinear shock absorber.
2016-04-05
Technical Paper
2016-01-0796
Ashish Shah, Per Tunestal, Bengt Johansson
This article presents a study related to application of pre-chamber ignition system in heavy duty natural gas engine which, as previously shown by the authors, can extend the limit of fuel-lean combustion and hence improve fuel efficiency and reduce emissions. A previous study about the effect of pre-chamber volume and nozzle diameter on a single cylinder 2 liter truck-size engine resulted in recommendations for optimal pre-chamber geometry settings. The current study is to determine the dependency of those settings on the engine size. For this study, experiments are performed on a single cylinder 9 liter large bore marine engine with similar pre-chamber geometry and a test matrix of similar and scaled pre-chamber volume and nozzle diameter settings. The effect of these variations on main chamber ignition and the following combustion is studied to understand the scalability aspects of pre-chamber ignition. Indicated efficiency and engine-out emission data is also presented.
2016-04-05
Technical Paper
2016-01-1062
Ramachandran Ragupathy, Pothiraj K, C Chendil, T Kumar Prasad, Prasanna vasudevan
In today's world where fuel efficiency and reduced emissions are fast becoming the order of the day, hybrid powertrains are a feasible intermediate step to clean transportation. Hybrid powertrains generally add an electric propulsion system in addition to propulsion power from conventional internal combustion engines. As such, the powertrain complexity increases both due to the number of interplaying systems and due to the advanced systems used to control system performance in an optimum manner. This paper shall describe, in detail and in particular, the effects of torsional impact loads in a mild hybrid electric powertrain and the mitigation measures adopted to resolve them. The powertrain configuration consists of a diesel engine with a crankshaft mounted electric machine. The torque from the engine/electric machine combination passes through a dry clutch to a manual transaxle.
2016-04-05
Technical Paper
2016-01-1108
Gordon McIndoe, Joseph VanSelous, Tongxiao Liu, Jeffrey David
Multi-mode powerpath configurations with a VariGlide continuously variable planetary transmission can yield wide ratio spreads with excellent transmission system efficiencies. A simulation methodology can be used to estimate the operating efficiencies for various power path configurations.
2016-04-05
Technical Paper
2016-01-0102
Michael Ludwig, Martin Rieder, Marco Wolf
The intent to reduce CO2-emssions and the necessity to assess the emission levels of car engines have resulted in implementation of the new European drive cycle (NEDC). To underrun targeted threshold values in the NEDC, an electrification of cars is inevitable. Different concepts, e.g. mild- and micro-hybrid, as well as plug-in hybrid approaches, are capable to achieve the target of 90g/km. What all these technologies have in common is that they are based on an electric engine which has to be commutated. Design examples comprise Belt-Driven Starter Generators, Integrated Starter Generators, or stand-alone electric motors. Rotor-position sensors (RPS) are used within these machines to gain the angle information of the rotor, and therefore this angle-information is directly linked to robustness and performance of the electric powertrain. The intent of this paper is the generation of an overview of different sensor technologies suitable for rotor-position measurement.
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