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Electrification and hybridization show great potential for improving fuel economy and reducing emission in heavy-duty vehicles. However, high battery cost is unavoidable due to the requirement for large batteries capable of providing high electric power for propulsion. Presenter Tae-Kyung Lee, Univ. of Michigan

Diesel exhaust aftertreatment systems are required for meeting both EPA 2010 and final Tier 4 emission regulations while meeting the stringent packaging constraints of the vehicle. The aftertreatment system for this study consists of a fuel dosing system, mixing elements, fuel reformer, lean NOx trap (LNT), diesel particulate filter (DPF), and a selective catalytic reduction (SCR) catalyst. The fuel reformer is used to generate hydrogen (H₂) and carbon monoxide (CO) from injected diesel fuel. These reductants are used to regenerate and desulfate the LNT catalyst. NOx emissions are reduced using the combination of the LNT and SCR catalysts. During LNT regeneration, ammonia (NH₃) is intentionally released from the LNT and stored on the downstream SCR catalyst to further reduce NOx that passed through the LNT catalyst. This paper addresses system packaging and exhaust flow optimization for heavy-duty line-haul and severe service applications.

Future government emission regulations have lead to the development and implementation of advanced aftertreatment systems to meet stringent emission standards for both on-road and off-road vehicles. These aftertreatment systems require sophisticated control and diagnostic strategies to ensure proper system functionality while minimizing tailpipe NOx and PM emissions across all engine operating conditions. In this paper, an integrated algorithm design approach with controls and diagnostics for an aftertreatment system consisting of a fuel doser, fuel reformer, LNT, DPF, and SCR is discussed.

Current concerns about climate change, energy security and record high oil prices have triggered high enthusiasm and push for plug-in vehicles. Widespread adoption of plug-in vehicles would result in significant reductions in CO2 emissions from transportation. It would also reduce our dependence on fossil fuels by replacing petroleum-sourced energy with renewable, domestically produced electricity. While a few OEMs have successfully launched hybrid vehicles and even toyed with plug-in hybrid solutions in the passenger car market segment, little attention has been placed on heavier commercial vehicles. Large utilities operate fleets of several hundred diesel-power trouble trucks to repair and maintain their transmission and distribution infrastructure. Medium-duty segment is over a million vehicles annually. These vehicles are typically driven in densely populated neighborhoods.

The emergence of tougher environmental legislations and ever increasing demand for increased ride comfort, fuel efficiency, and low emissions have triggered exploration and advances towards more efficient vehicle gearbox technologies. The growing complexity and spatial distribution of such a mechatronic gearbox demands precise timing and coordination of the embedded electronics, integrated sensors and actuators as well as excellent overall reliability. The increased gearbox distributed systems have seen an increased dependence on sensors for feedback control, predominantly relying on hardware redundancy for faults diagnosis. However, the conventional hardware redundancy has disadvantages due to increased costs, weight, volume, power requirements and failure rates. This paper presents a virtual position sensor-based Fault Detection, Isolation and Accommodation (FDIA), which generates an analytical redundancy for comparison against the actual sensor output.

Electro-hydraulic actuated systems are widely used in industrial applications due to high torque density, higher speeds and wide bandwidth operation. However, the complexities and the parametric uncertainties of the hydraulic actuated systems pose challenges in establishing analytical mathematical models. Unlike electro-mechanical and pneumatic systems, the nonlinear dynamics due to dead band, hysteresis, nonlinear pressure flow relations, leakages and friction affects the pressure sensitivity and flow gain by altering the system's transient response, which can introduce asymmetric oscillatory behavior and a lag in the system response. The parametric uncertainties make it imperative to have condition monitoring with in-built diagnostics capability. Timely faults detection and isolation can help mitigate catastrophic failures. This paper presents a signal-based fault diagnostic scheme for a gearbox hydraulic actuator leakage detection using the wavelet transform.

In this paper, an optimization method is proposed to improve the efficiency of a transmission equipped electric vehicle (EV) by optimizing gear shift strategy. The idea behind using a transmission for EV is to downsize the motor size and decrease overall energy consumption. The efficiency of an electric motor varies with its operating region (speed/torque) and this plays a crucial role in deciding overall energy consumption of EVs. A lot of work has been done to optimize gear shift strategy of internal combustion engines (ICE) based automatic transmission (AT), and automatic-manual transmissions (AMT), but for EVs this is still a new area. In case of EVs, we have an advantage of regeneration which makes it different from the ICE based vehicles. In order to maximize the efficiency, a heuristic search based algorithm - Genetic Algorithm (GA) is used.

In response to the need for lightweight design in industries, composite materials are increasingly used to replace traditional metal tubes. However, subsurface defects such as voids, delaminations, and microcracks are still remaining common issues in composite pressure tubes. This paper introduces an application of Digital Shearography method in the Non-Destructive Testing (NDT) of high-pressure composite tubes. A new prototype high-pressure composite tube with a working pressure of 1000 psi range is tested using the digital Shearography method. To detect the sub-surface defects, a reference Shearographic phase map is created at 0 psi state, after that the composite tube is pressured using an oil pump, then the second Shearographic phase map is created at the pressured state. By subtracting the two shearographic phase maps created in different pressure state, the sub-surface defects can be identified clearly. The Shearographic NDT result is then compared with CT scan result.

Eaton has been working on technologies for cost effective, reliable and safe Automated Mechanical Transmissions (AMTs) since the mid 1970's. The company has introduced three different systems since the late 1980's, but all three systems were constrained by the lack of precise engine speed control during shifting. With the advent of electronic engine controls the constraint has been removed and precise engine speed control during shifting can be easily accomplished. The result is a simplified system that is powerfully intelligent and fully capable of automatic shifting i.e., the transmission system determines when to shift and executes the shift without any driver inducement across the broad spectrum of truck usage. This paper discusses some of the AMTs available to the truck market, showing how the system benefits both the OEM and the end user.

An alternative to the current drum brakes, with the increased requirements of todays daily service are disc brakes, in that they offer, in contrast to the drum brakes, the following technical advantages and in turn enhance the active safety of modern commercial vehicles when braking: Enhanced brake pedal-feedback and actuation Improved efficiency Little performance losses when high thermal loads occur (fading). In order to be able to determine the improvement potential of disc brakes they will be compared to the commonly employed Simplex drum brakes. Both wheel brake systems (disc-/drum brakes and all variations) were tested on a computer controlled brake dynamometer and in field tests using a heavy duty commercial vehicle (class 8). The results are compared and conclusions drawn regarding “advantages/disadvantages”.

Stringent space constraints for on and off highway vehicles require compact exhaust aftertreatment system packaging to meet both EPA 2010 and final Tier 4 emission regulations. Development and validation of a compact diesel fuel vaporization and mixing system is the focus of this work. The fuel vaporization and mixing system is comprised of a fuel dosing system, catalytic monolith and mechanical mixer. A fuel reformer, lean NOx trap (LNT), diesel particulate filter (DPF) and a selective catalytic reduction (SCR) catalysts are positioned downstream of the fuel vaporizer system. A 44% reduction in total fuel vaporization / mixing path length was achieved using an optimized injection chamber, catalytic monolith and mixing element. Reformer outlet temperature results confirm that reformer inlet fuel vapor uniformity targets meet design specifications. Similarly, the fuel reformer efficiency using the fuel vaporizer met the design targets within the compact packaging envelope.

The current Brazilian tax legislation promotes vehicles, powered by engines with up to 1.0l displacement. In order to offer the customer an engine with the maximum tax advantage, a supercharged derivative of the Ford 1.0l Zetec RoCam engine was developed. The market specific boundary conditions in South America require powertrains with immediate response especially at low engine speeds. This can be achieved by a supercharged engine concept. The paper discusses the required engine modifications for the supercharger application. The combustion system was changed to benefit from the higher volumetric efficiency, including the optimisation of the intake, exhaust and bypass control system. Extensive modifications of the base engine were required to adapt the engine to the higher thermal load and the specific boundary condition of a supercharger application.

There is an increased use of elastomers in the automotive industry for sealing, noise isolation, load dampening, insulation, etc., because of their key properties of elasticity and resilience. Elastomers are used in supercharger application for dampening the torsional fluctuation from the engine, to reduce noise issues. Finite element modeling of elastomers is challenging because of its non-linear behavior in different loading directions. It also undergoes very large elemental deformation (~up to 200%), which results in additional complexities in getting numerical convergence. Finally, it also exhibits viscous and elastic behavior simultaneously (viscoelastic effect) and it undergoes softening with progressive cyclic loading (Mullins effect). The present study deals with the characterization of elastomers for its modeling in commercial finite element software packages and verification of some predicted design parameters with physical testing.

The open (standard) differential provides an important function in vehicle dynamics and handling by splitting the applied driveline torque and allowing each wheel or axle to spin at different speeds. This function is necessary to eliminate axle bind-up while negotiating turns. However, it inherently impedes optimal traction and mobility performance by allowing the available torque to be limited by the wheel or axle having the least amount of traction. Loss of traction could result in loss of driveline torque control and a resulting loss of vehicle control. This loss of control could be catastrophic in the case of higher speed maneuvers. The proposed electronically controlled hydraulic limited slip differential solution corrects this problem, seamless to the driver, while maintaining the fundamental open differential function. Furthermore, this system maintains efficient forward motion compared to other solutions that slow the vehicle down while expending valuable energy.

The increased trend of automatic and automated transmissions across a breadth of applications is one of the market drivers for the development of wet clutch systems. Key product differentiators that drive the use of wet clutches in specific applications are (a) Compactness, (b) Low inertia, (c) Higher energy density, (d) Better NVH characteristics, and (e) Longer wear life. The above-stated product differentiators are dependent on performance of both the clutch cooling system and the friction system for two different operating events, namely engagement and disengagement. During engagement, slip under load between the clutch plates generates heat, which must be carried away by the oil, necessitating a high oil flow demand to all friction surfaces. Failing to achieve this leads to excessive plate temperatures and wear, ultimately resulting in poor performance and reduced clutch life.

Eaton has supported the design and development of spoilers for automobile applications. Addition of spoilers in the car influences the external aerodynamics and in turn impacts fuel economy and vehicle stability, in addition to providing improved external aesthetics. With the upward trend in fuel prices, it becomes more critical to quantify the effect of spoiler on the fuel economy. Eaton Corporation has undertaken efforts to establish predictive capability for evaluating the effect of a rear mounted spoiler on fuel economy. A first phase of these efforts focuses on development of a CFD methodology on the Ahmed Reference model and validation with wind tunnel testing. A second phase will focus on leveraging the methodology on an actual automobile and in the last phase, fuel economy models will be built using outputs from the CFD methodology. This paper focuses on detailed discussion about first phase of the work and summary of the second phase.

Creep is responsible for creating time dependent changes in product dimensions and reducing strength that could affect the ability of products to resist design loads. Creep behavior is an important design consideration for polymers as this phenomenon is observed at very low temperatures compared to metals. Literature suggests many mathematical models to represent this complex creep phenomenon; however they are limited to most common polymers. Today's automotive industry is equipped with state of the art polymer materials considering specific design requirements from the stake holders. The current study is focused on the engine oil pan and its sealing requirements for the automotive business. Computer Aided Engineering (CAE) plays a very critical role in today's quest to reduce the design cycle and testing time.

Commercial vehicle operators and governments around the world are looking for ways to cut down on fuel consumption for economic and environmental reasons. Two main factors affecting the fuel consumption of a vehicle are the drive route and the driver behavior. The drive route can be specified by information such as speed limit, road grade, road curvature, traffic etc. The driver behavior, on the other hand, is difficult to classify and can be responsible for as much as 35% variation in fuel consumption. In this work, nearly 600,000 miles of drive data is utilized to identify driving behaviors that significantly affect fuel consumption. Based on this analysis, driving scenarios and related driver behaviors are identified that result in the most efficient vehicle operation. A driver assistance system is presented in this paper that assists the driver in driving more efficiently by issuing scenario specific advice.

Vehicle electrification is being actively expanded into coming generations of passenger and commercial vehicles. This technology trend is helping vehicles to become more energy efficient. For electric vehicle (EV) city bus application, the system designers have been experimenting with a number of options including direct drive and multi-speed gearbox architectures. Direct drive scenario offers simplified drivetrain system, however requires a large and powerful electric motor. Multi-speed transmission system provides an opportunity to reduce motor size and optimize its operating points, but increases complexity from the architecture and controls point of view. This paper provides an overview of several common system layouts and examines their advantages and disadvantages. Vehicle simulation results are presented to compare direct drive vs. multi-speed technology from the gradeability, acceleration and energy consumption points of view.

Downsizing and downspeeding have become accepted strategies to reduce fuel consumption and criteria pollutants for automotive engines. Engine boosting is required to increase specific power density in order to retain acceptable vehicle performance. Single-stage boosting has been sufficient for previous requirements, but as customers and governments mandate lower fuel consumption and reduced emissions, two-stage boosting will be required for downsized and downsped engines in order to maintain performance feel for common class B, C, and D vehicles. A 1.6L-I4 diesel engine model was created, and three different two-stage boosting systems were explored through engine and vehicle level simulation to reflect the industry's current view of the limit of downsizing without degrading combustion efficiency with cylinder volumes below 400 cm₃. Some current engines are already at this size, so downspeeding will become much more important for reducing fuel consumption in the future.