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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.

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.

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.

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.

A cylinder deactivation system has been developed for use on dual overhead camshaft (DOHC), roller finger follower valvetrain engine applications. Cylinder deactivation is emerging as an effective means to reduce fuel consumption in vehicles, especially those equipped with V6 or V8 engines. This paper addresses a new system that accomplishes this function through the use of a switching roller finger follower (SRFF). This system includes key design features that allow application of the SRFF without affecting overall width, height, or length of DOHC engines. Emphasis was placed on reducing the moment of inertia over the SRFF pivot without compromising rocker arm stiffness. The switching mechanism for transitioning between normal and deactivated operation is hydraulically actuated with engine oil. The switching windows are identified in terms of temperature, pressure, and engine speed. High engine speed test results show stable valvetrain dynamics above 7000 rpm engine speed.

A method for measuring diesel fuel consumption accurately over short distances of 5 miles or less was developed so that many fan-on, fan-off data sets could be gathered in a short time for statistical evaluation and analysis. A second test sequence involved fan-on, fan-off fuel economy tests over a highway route for comparison against the Cummins Vehicle Mission Simulation Computer Program. The predicted results from this program agreed substantially with the actual highway economy test data we obtained. More than 4 million charted miles of roads throughout the world are available through this program for predicting fan-off fuel savings. Results on several typical routes are given.

The fundamental features in designing a valve gear are discussed in this paper. Covered are: valve types; operating mechanisms; valve gear design considerations; and component design considerations such as valves, valve guides, spring retainers and locks, the cam follower, the camshaft, and valve springs.

The paper suggests the benefits to be gained from using an electronic thermostat to improve control over the coolant temperature of an operating gasoline engine. It also describes the work undertaken to confirm that engine temperature can be maintained at a selected level and that the temperature level can be raised or lowered as desired in a running vehicle. The common automotive mechanical thermostat has the limitation of a fixed operating point with coolant flow rate dependent on temperature rise. Over its long life it has been refined economically to the point where the advantages of a more sophisticated device, made possible with electronics, have not been explored in depth. Recent electronic advances, however, make possible the addition of features that should justify the economic differential. The advantages and features that can be obtained with an electronic thermostat will be presented along with design considerations and test results.

Exhaust valve guttering is a corrosive process that takes place on the valve seat face. Detroit Diesel Allison Division of General Motors and Eaton Corporation have developed an accelerated test to gutter exhaust valves. The test was used to rank seven factors considered to be significant oil consumption, lubrication oil ash content and injector timing were found to be the major contributors to guttering.

Optimization of vehicle air conditioning performance at various drive cycles and ambient conditions can be achieved by regulating and distributing the refrigerant flow entering evaporators. Thermostatic expansion valve (TXV), as a flow control device, has been a key element in improving vehicle A/C system operating efficiency and maximizing cooling capacity. Three scenarios are addressed in this paper: (a) the selection of TXVs for a sports utility vehicle (SUV) climate control system, in which a front HVAC unit and an auxiliary HVAC unit are installed; (b) the methodology of developing a goal-oriented criterion for identifying the TXV combination to fulfill the optimization of A/C system performance; and (c) the analytical and experimental evaluation of vehicle cooling performance by varying TXV combinations in various vehicle operating modes.

Effective control of exhaust emissions from modern diesel engines requires the use of aftertreatment systems. Elevated aftertreatment component temperatures are required for engine-out emissions reductions to acceptable tailpipe limits. Maintaining elevated aftertreatment components temperatures is particularly problematic during prolonged low speed, low load operation of the engine (i.e. idle, creep, stop and go traffic), on account of low engine-outlet temperatures during these operating conditions. Conventional techniques to achieve elevated aftertreatment component temperatures include delayed fuel injections and over-squeezing the turbocharger, both of which result in a significant fuel consumption penalty. Cylinder deactivation (CDA) has been studied as a candidate strategy to maintain favorable aftertreatment temperatures, in a fuel efficient manner, via reduced airflow through the engine.

Fuel economy of both highway and off-highway vehicles is a major driver for new technology development. One of the technologies to meet this driver is a digital valve based hydraulic system. Digital Hydraulics technology employs high speed on/off valves to achieve the same functionality with no throttling loss. Furthermore, by forming various architecture by using digital valves, it provides the system level capability and flexibility for energy saving and productivity improvement. There are many challenges in fully realizing the full efficiency benefits of the system in an actual application. These challenges include packaging, durability, a change in the operator's perception of the vehicle as well as hydraulic system performances during operation. One significant issue is the noise, vibration and harshness (NVH) of the system. Due to the nature of the digital valve operation, there are severe transient dynamics in the fluid system.

An advanced Variable Valve Actuation (VVA) system is optimized for response time in order to provide robust switching at high engine speeds. The VVA system considered is Cylinder Deactivation (CDA) for the purpose of improving fuel economy. Specifically, a Switching Roller Finger Follower (SRFF) on a Dual Overhead Camshaft (DOHC) engine is optimized for cylinder deactivation. The objective of this work is to (1) improve the latch response time when the system response is the slowest, and (2) balance the “ON” and “OFF” response time. A proper tradeoff was established to provide the minimum switching time such that deactivation and reactivation occurs seamlessly and in the right sequence. The response time optimization is accomplished while maintaining the existing packaging space of the overhead. A camshaft with a single lobe per SRFF device on a type II valvetrain was used as the baseline configuration for this study.