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With increasing demands to reduce emissions from internal combustion engines, engine manufacturers are forced to seek out new technology. One such technology employed primarily in the diesel and two-stroke engine community is direct-injection (DI). Direct injection has shown promising results in reduction of CO and NOx for both two- and four-stroke engines. While having been used for several years in the diesel industry, direct injection has been scrutinized for an inability to meet future requirements to reduce particulate matter emissions. Direct injection has also came under fire for complicating fuel delivery systems, thus making it cost prohibitive for small utility engine manufacturers. Recent research shows that the application of piezo-driven actuators has a positive effect on soot formation reduction for diesel engines and as this paper will distinguish, has the ability to simplify direct injection fuel delivery systems in general.

It is well-known that the hydrodynamic torque converter plays a major role in the transient study of power train systems since it has a great influence on the transient characteristics of a vehicle during gear shifting as well as vehicle launching. To predict accurately the vehicle characteristics, detailed analysis of the hydrodynamic torque converter is required. However, even with the development of a nonlinear dynamic model for the torque converter based on Hrovat and Tobler's paper (1985) is available, it is imperative to calculate both torques from impeller and turbine in order to utilize the dynamic model since it takes torque as an input [3]. In order to obtain the information about necessary but unmeasurable variables, nonlinear model-based estimator is developed using already available and measurable speeds data of impeller and turbine. The hydrodynamic torque converter model includes all necessary dynamics, namely, hydraulic as well as mechanical dynamics.

This paper presents the details of the model for the physical steering system used on the National Advanced Driving Simulator. The system is basically a hardware-in-the-loop (steering feedback motor and controls) steering system coupled with the core vehicle dynamics of the simulator. The system's torque control uses cascaded position and velocity feedback and is controlled to provide steering feedback with variable stiffness and dynamic properties. The reference model, which calculates the desired value of the torque, is made of power steering torque, damping function torque, torque from tires, locking limit torque, and driver input torque. The model also provides a unique steering dead-band function that is important for on-center feel. A Simulink model of the hardware/software is presented and analysis of the simulator steering system is provided.

Amongst various sources of noise and vibrations in gear meshing, transmission error and sliding friction between the teeth are two major constituents. As the operating conditions are altered, the magnitude of these two excitations is affected differently and either of them can become the dominant factor. In this article, an experimental investigation is presented for identifying the friction excitation and to study the influence of tribological parameters on the radiated sound. Since both friction and transmission error excitations occur at the same fundamental period of one meshing cycle, they result in similar spectral contents in the dynamic response. Hence specific methods like the variation of parameters are designed in order to distinguish between the individual vibration and noise sources. The two main tribological parameters that are varied are the lubricant and the surface finish characteristics of gear teeth.

Many automotive components and sub-systems require viscoelastic damping treatments to control noise and vibration characteristics. To aid the dynamic design process, new approaches are needed for modeling of partial damping treatments and characterization of the overall dynamic behavior. The analytical component of the design process is illustrated via the transmission casing cover, along with supporting experiments. First, the vibration response of production casing plates is examined, with and without the constrained layer treatment. A modified flat plate is employed along with a generic housing that provides the realistic boundary conditions for subsequent work. A simplified analytical damping model for constrained viscoelastic layer damping is suggested based on assumed modal functions. Using the analytical model, design guidelines in terms of optimal patch shapes and locations are suggested.

In many vibration isolation problems, translational motion has been regarded as a major contributor to the energy transmitted from a source to a receiver. However, the rotational components of isolation paths must be incorporated as the frequency range of interest increases. This article focuses on the flexural motion of an elastomeric isolator but the longitudinal motion is also considered. In this study, the isolator is modeled using the Timoshenko beam theory (flexural motion) and the wave equation (longitudinal motion), and linear, time-invariant system assumption is made throughout this study. Two different frequency response characteristics of an elastomeric isolator are predicted by the Timoshenko beam theory and are compared with its subsets. A rigid body is employed for the source and the receiver is modeled using two alternate formulations: an infinite beam and then a finite beam. Power transmission efficiency concept is employed to quantify the isolation achieved.

This year, in the third year of FutureTruck competition, the Ohio State University team has taken the challenge to convert a 2002 Ford Explorer into a more fuel efficient and environmentally friendly SUV. This goal was achieved by use of a post-transmission, charge sustaining, parallel hybrid diesel-electric drivetrain. The main power source is a 2.5-liter, 103 kW advanced CIDI engine manufactured by VM Motori. A 55 kW Ecostar AC induction electric motor provides the supplemental power. The powertrain is managed by a state of the art supervisory control system which optimizes powertrain characteristics using advanced energy management and emission control algorithms. A unique driver interface implementing advanced telematics, and an interior designed specifically to reduce weight and be more environmentally friendly add to the utility of the vehicle as well as the consumer appeal.

Transmission error has long been identified to be the main exciter of gear whine noise. This research effort seeks to investigate the mechanisms and principal controlling factors that affect the actual noise generation from a typical gearbox housing due to transmission error excitations. The insight gained is expected to help in identifying possible noise control procedures in typical gearing applications. The example gearbox of this paper is an aircraft auxiliary-drive idler gearbox run at low load so that transmission error is the primary mesh excitation. A limited set of dynamic noise and vibration data are collected in transient speed run-ups. A contact-mechanics gear-tooth model is used to predict the static transmission error at each mesh. A finite-element model of the shafting that incorporates complex shaft and bearing data is used to predict the shaft dynamics with the static transmission error at the gear mesh(es) as the sole excitation.

Structure-borne noise within vehicle structures is often transmitted in a multi-dimensional manner and thus the vibro-acoustic model(s) of automotive powertrain or chassis must incorporate longitudinal and transverse (flexural) motions as well as their couplings. In this article, we employ the continuous system theory to model a typical vibration isolator (say the engine mounting system) and a compliant receiver that could simulate the body structure. The powertrain source is however assumed to be rigid, and both harmonic force and moment excitations are considered. Our analysis is limited to a linear time-invariant system, and the frequency domain based mobility method is utilized to synthesize the overall system. Contributions of both in-plane and flexural motions to structure-borne and radiated noise are incorporated. Two examples are considered to illustrate the methodology.

The acoustic characteristics of a hybrid silencer consisting of two dissipative chambers and a Helmholtz resonator are investigated first computationally and experimentally. Complex wave number and characteristic impedance are used for the dissipative chambers to account for the wave propagation through absorbing material. Three-dimensional boundary element method (BEM) is employed to predict the transmission loss in the absence of mean flow and the predictions are compared with the experimental results obtained from an impedance tube setup. Noting that the long connecting tube between acoustic elements may reduce the transmission loss near the resonance frequency, two alternative hybrid silencers with short connecting tubes are also investigated by BEM. The present study shows the effectiveness of hybrid silencers over a wide frequency range and demonstrates the importance of understanding each acoustic element, as well as their interaction in designing silencers.

Prediction of power efficiency of gear boxes has become an increasingly important research topic since fuel economy requirements for passenger vehicles are more stringent, due to not only fuel cost but also environmental regulations. Under this circumstance, the automotive industry is dedicatedly focusing on developing a highly efficient gear box. Thus, the analysis of power efficiency of gear box should be performed to have a transmission that is highly efficient as much as possible at the beginning of design stage. In this study, a program is developed to analyze the efficiency of an entire gearbox, considering all components’ losses such as gear mesh, wet clutches, bearings, oil pump and so on. The analytical models are based on the formulations of each component power loss model which has been developed and published in many existing papers. The program includes power flow analysis of both a parallel gear-train and a planetary gear-train.

The EcoCAR 2: Plugging into the Future team at the Ohio State University is designing a Parallel-Series Plug-in Hybrid Electric Vehicle capable of 50 miles of all-electric range. The vehicle features a 18.9-kWh lithium-ion battery pack with range extending operation in both series and parallel modes. This is made possible by a 1.8-L ethanol (E85) engine and 6-speed automated manual transmission. This vehicle is designed to drastically reduce fuel consumption, with a utility factor weighted fuel economy of 51 miles per gallon gasoline equivalent (mpgge), while meeting Tier II Bin 5 emissions standards. This report details the fabrication and control implementation process followed by the Ohio State team during Year 2 of the competition. The fabrication process includes finalizing designs based on identified requirements, building and assembling components, and performing extensive validation testing on the mechanical, electrical and control systems.

Fault diagnosis for automotive systems is driven by government regulations, vehicle repairability, and customer satisfaction. Several methods have been developed to detect and isolate faults in automotive systems, subsystems and components with special emphasis on those faults that affect the exhaust gas emission levels. Limit checks, model-based, and knowledge-based methods are applied for diagnosing malfunctions in emission control systems. Incipient and partial faults may be hard to detect when using a detection scheme that implements any of the previously mentioned methods individually; the integration of model-based and knowledge-based diagnostic methods may provide a more robust approach. In the present paper, use is made of fuzzy residual evaluation and of a fuzzy expert system to improve the performance of a fault detection method based on a mathematical model of the engine.

Measurements of the temporal evolution of the 3-D velocity field were performed in an IC engine during the latter part of the intake stroke using a Water Analog Engine Simulation Rig and the 3-D Particle Tracking Velocimetry technique (3-D PTV). The engine head tested was a typical 4 valve, pent-roof type combustion chamber shape with slightly asymmetric intake passages to favor a preferred swirl with one intake valve almost deactivated to reinforce the swirling flow pattern. This study was aimed at characterizing the dynamic development of the flow field resulting from this head geometry and asymmetric valve event during the latter part of the intake stroke. The most salient feature of this flow field is that this final, highly organized and energetic vortex does not emerge until relatively late in the intake stroke. Even as late at 60° BBDC, the flow field is still characterized by smaller (of the order of 1/4 or 1/3 of the bore size) structures, particularly in the tumble plane.

Over the years numerous researchers have suggested that the ionization current signal carries within it combustion relevant information. The possibility of using this signal for diagnostics and control provides motivation for continued research in this area. To be able to use the ion current signal for feedback control a reliable estimate of some combustion related parameter is necessary and therein lies the difficulty. Given the nature of the ion current signal this is not a trivial task. Fei An et al. [1] employed PCA for feature extraction and then used these feature vectors to design a neural network based classifier for the estimation of air to fuel ratio (AFR). Although the classifier predicted AFR with sufficient reliability, a major draw back was that the ion current signals used for prediction were averaged signals thus precluding a cycle to cycle estimate of AFR.

This paper presents the modeling of an Electromagnetic Valve Actuator (EMV). A nonlinear model is formulated and presented that takes into account secondary nonlinearities like hysteresis, saturation, bounce and mutual inductance. The uniqueness of the model is contained in the method used in modeling hysteresis, saturation and mutual inductance. Theoretical and experimental methods for identifying parameters of the model are presented. The nonlinear model is experimentally validated. Simulation and experimental results are presented for an EMV designed and built in our laboratory. The experimental results show that sensorless estimation could be a possible solution for position control.

Springback affects the dimensional accuracy and final shape of stamped parts. Accurate prediction of springback is necessary to design dies that produce the desired part geometry and tolerances. Springback occurs after stamping and ejection of the part because the state of the stresses and strains in the deformed material has changed. To accurately predict springback through finite element analysis, the material model should be well defined for accurate simulation and prediction of stresses and strains after unloading. Despite the development of several advanced material models that comprehensively describe the Bauschinger effect, transient behavior, permanent softening of the blank material, and unloading elastic modulus degradation, the prediction of springback is still not satisfactory for production parts. Dies are often recut several times, after the first tryouts, to compensate for springback and achieve the required part geometry.

It is well-known that the shift hydraulic system plays a major role in the operation of stepped automatic transmissions. The main functions of the hydraulic system are to generate and maintain adequate fluid pressures for transmission operation, as well as to initiate gear shifts and control shift quality. Therefore, quantitative understanding of the dynamic behavior of the hydraulic system is critical to the improvement of automatic transmission performance. This paper presents the development of a nonlinear dynamic model for the shift hydraulic system of a stepped automatic transmission. The model includes all necessary dynamics, namely, hydraulic line pressure dynamics, solenoid valve dynamics, pressure control valve dynamics, as well as clutch and accumulator dynamics. The model is developed and implemented using Matlab/Simulink®, and is validated against experimental data.

The influence of die corner geometry on the attainable draw depth of rectangular parts was investigated using 3-D FEM and optimum rectangular blanks. Axisymmetric cup analysis was not adequate because a corner assist effect promotes corner draw. Guidelines for selecting corner radius were developed and the sensitivities of the maximum part depth to other process variables, such as drawbead restraint force; die clearance gap; friction coefficient; strain rate sensitivity; material anisotropy; and strain hardening exponent, were simulated. The results are much more conservative than handbook rules, which to not to take into account the details of blank size, drawbead restraint, die geometry, material properties, and friction.

A prototype hybrid exhaust silencing system consisting of dissipative and reactive components is designed based on the boundary element method (BEM) with a specific emphasis on its acoustic performance as evaluated relative to a production system. The outer dimensions of the prototype system are comparable to its production counterpart, which has two silencers connected by a pipe. The predicted transmission loss by BEM for the prototype is compared with the experimental results in an impedance tube for both the prototype and production hardware, providing a design guidance for the former. The sound pressure levels measured at the tailpipe exit during the engine ramp-up experiments in a dynamometer laboratory are presented to compare the two systems, providing the final assessment.