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Electrical power generation is an important component in the Electrical Power System of an Aircraft (EPS). In this paper we present a model based diagnostic framework for early generator degradation detection and tracking within an Aircraft Generator. The nominal health state is modeled empirically using an Auto-associative Kernel Regression (AAKR) technique using signals extracted from a healthy generator. Later the health state is estimated by comparing sensor observations with the model predictions. Finally, a Sequential Probability Ratio Test (SPRT) is used to detect and track degradation. This model based framework showed excellent degradation tracking performance when it was tested on a unit that was run to failure.

Aviation battery maintenance is trending toward on-condition maintenance. Nickel-Cadmium (NiCd), Valve Regulated Lead-Acid (VRLA), or prospective Li-ion batteries are used to start engines, provide emergency back-up power, and assure ground power capability for maintenance and pre-flight checkout. As these functions are mission essential, State of Health (SoH) recognition is critical. SoH includes information regarding battery energy, power and residual cycle life. This paper describes an SoH recognition technique for on-board aviation batteries and presents a passive diagnostic device (PDD). The PDD monitors on-board system battery current, voltage and ambient temperature and utilizes no active signals to the battery which can be restricted or even prohibited in order to avoid any interference with the vehicle electrical system.

The Cessna Citation CJ4, certified on March 12, 2010, is believed to be the first civil aircraft with a Lithium Ion main battery. The 26.4VDC, 44Ah Lithium Ion main battery weighs 54 lbs, a 35% weight saving over a Nickel-Cadmium battery. Using phosphate-based Lithium Ion cells, which have no positive feedback thermal runaway failure mode, system integration of the battery and aircraft architecture design is simpler. Electronics and software are needed to optimize life only, not to ensure safety. Emergency discharge with failed electronics is enabled with the selection of a less volatile chemistry, the use of an analog Module Management System for cell balancing and protection, and the use of a microcontroller-based digital Central Monitoring System that reports health. System safety failure hazard assessment is considered Major, and the battery software is certified to the requirements of RTCA DO-178B, Design Assurance Level C.

The focus of this research is to perform a detailed investigation of the tradeoffs between mass, efficiency, service factor (SF), power factor (PF), and cost of commercially available induction machines (IMs). To support this effort, data from a large number of IMs is used to establish Pareto-optimal fronts between these competing objectives. From the Pareto-optimal fronts, relatively straightforward models are formulated for the mass versus loss, cost versus loss, SF versus mass, PF versus cost. Parameters of the models are obtained using a genetic algorithm (GA).

Compliance with tighter emission regulations has increased the proportion of parasitic weight in commercial vehicles. In turn, the amount of payload must be reduced to comply with transportation weight requirements. A re-design of commercial vehicle components is necessary to decrease the vehicle weight and improve payload capacity. Side rails have traditionally been manufactured from high strength steels, but significant weight reductions can be achieved by substituting steel side rails with 6013 high strength aluminum alloy side rails. Material and stress analyses are presented in this paper in order to understand the effect of manufacturing process on the material's mechanical behavior. Metallographic and tensile test experiments for the 6013-T4 alloy were performed in preparation for residual stress measurements of a punching operation. Punched holes are critical to the function of the side rail and can lead to high stress levels and cracking.

The paper will discuss the design and development of heavy-duty diesel engines to meet the US EPA 2010 on-highway standards - 0.2 g/HP-hr NOx and 0.01 g/HP-hr particulate matter (PM). In meeting these standards a combination of in-cylinder control and aftertreatment control for both NOx and particulate has been used. For NOx control, a combination of cooled exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) is used. The SCR catalyst uses copper zeolite to achieve high levels of NOx conversion efficiency with minimal ammonia slip and unparalleled thermal durability. For particulate control, a diesel particulate filter (DPF) with upstream oxidation catalyst (DOC) is used. While the DPF may be actively regenerated when required, it operates predominantly with passive regeneration - enabled by the high NOx levels between the engine and the DPF, associated with high efficiency SCR systems and NO₂ production across the DOC.

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.

The paper presents linear and non-linear driveline models for Heavy Goods Vehicles (HGVs) in order to evaluate the main parameters for optimal tuning, when considering the drivability. The implemented models consider the linear and non-linear driveline dynamics, including the effect of the engine inertia, the clutch damper, the driveshaft, the half-shafts and the tires. Sensitivity analyses are carried out for each driveline component during tip-in maneuvers. The paper also analyses the overall frequency response using Bode diagrams and natural frequencies. It is demonstrated that the most basic model capable of taking into account the first order dynamics of the driveline must consider the moments of inertia of the engine, the transmission and the wheels, the stiffness and the damping properties of the clutch damper, driveshaft and half-shafts, and the tires (which link the wheel to the equivalent inertia of the vehicle).

An effort was undertaken to capture the relationship between the output of mass flow sensors and the input rate of mass flow for harvesting combines with yield monitors. Different types of models were considered that characterize this relationship and that can be applied to a variety of mass flow sensor technologies. Issues such as implementation during harvesting and calibration of these sensors and models were explored. Additionally, an example of such a model and its validation against experimental data was examined. For small-scale laboratory experiments, the model was shown to closely capture the general trend of the data as well as to yield reasonable estimates of the mass flowing through the system based on the sensor output. For large-scale experiments, the model was able to be fitted to the experimental data, and to estimate mass flow rate with relatively low errors across a variety of operating conditions.

This paper develops a novel integrated navigational system for autonomous vehicle motion control. Vehicle control is defined in terms of the required vehicle steering angle, rate of steering change and speed. This paper proposes predictive control in the image plane. The proposed predictive control enables the navigation on the desired path, reduces the control complexity and increases the application space for multiple types of vehicles. The paper investigates vehicle control stability; especially in scenarios containing varying curvature turns and variable vehicle speeds. The primary emphasis of this paper is on vehicle control rather than scene analysis. To demonstrate the proposed vehicle control, a computer vision based multi-lane detection algorithm is introduced. The control strategy is applied such that the vehicle maintains position within the lane boundaries. Stability of the control algorithm is tested and demonstrated in multiple scenarios using 3-D simulation results.

The ride dynamics of typical North-American soil compactors were investigated via analytical and experimental methods. A 12-degrees-of-freedom in-plane ride dynamic model of a single-drum compactor was formulated through integrations of the models of various components such as driver seat, cabin, roller drum and drum isolators, chassis and the tires. The analytical model was formulated for the transit mode of operation at a constant forward speed on undeformable surfaces with the roller vibrator off. Field measurements were conducted to characterize the ride vibration environments during the transit mode of operation. The measured data revealed significant magnitudes of whole-body vibration of the operator-station along the vertical, lateral, pitch and roll-axes. The model results revealed reasonably good agreements with ranges of the measured vibration data.

With the growing environmental concerns, biodegradable materials are gaining more importance. Biocomposites which are made from a combination of biological fiber such as flax and hemp together with plastics are finding a good number of applications in day to day life. Flax has good physical and mechanical properties that can be utilized in areas like construction, biomedical & bioproducts and electronics applications. The quality of fiber depends upon various unit operations used in the processing. Drying is one of the most important unit operations which significantly affect the quality of the fiber. The method of drying for removal of moisture from the fiber significantly affects the drying time and quality. In the present study the raw flax fiber was subjected to drying before and after chemical treatment. The physical properties such as; tensile strength, color and structural changes were measured for raw and chemically treated flax fibers.

In 2006, there were approximately 23,500 rear-end crashes involving heavy trucks (i.e., gross vehicle weight greater than 4,536 kg). The Enhanced Rear Signaling (ERS) for Heavy Trucks project was developed by the Federal Motor Carrier Safety Administration (FMCSA) to investigate methods to reduce or mitigate those crashes where a heavy truck has been struck from behind by another vehicle. Visual warnings have been shown to be effective, assuming the following driver is looking directly at the warning display or has his/her eyes drawn to it. A visual warning can be placed where it is needed and it can be designed so that its meaning is nearly unambiguous. FMCSA contracted with the Virginia Tech Transportation Institute (VTTI) to investigate potential benefit of additional rear warning-light configurations as rear-end crash countermeasures for heavy trucks.

The physical and optical properties viz., water absorption pattern, density, color and opacity of oil palm fiber-LLDPE composites were studied. The effect of fiber size, fiber loading and fiber treatment on the above parameters was also studied. Alkali treatment on fibers was done to reduce the hydrophilic nature of composites. It was found that the water absorption in most of the combinations followed typical fickian behavior. The rate of water absorption and swelling increased with fiber loading. However alkali treatment on fibers resulted in reduction of water absorption at higher fiber loading only and composites with higher fiber size exhibited higher water absorption. True density of oil palm fiber-LLDPE composites were in the range of 967-1177 kg m-₃, whereas the bulk density ranged from 942-1122 kg m-₃. The dielectric constant of the composite was in the range of 3.22 to 6.73.

The research on using natural fibres as the reinforcement in plastic composites has increased dramatically in the last few years. Flax fibres are renewable resources with low specific mass, reduced energy consumption, and relatively low in cost. These advantages make flax fibres recognized as a potential replacement for glass fibres in composites. Among plastic, polyethylene was concluded to be a suitable material used as matrix in natural fibre reinforced biocomposites. However there are few studies on this area so far. In this paper, the processing method of flax fibre-reinforced polyethylene biocomposites is introduced. Flax fibre polyethylene biocomposite consists of flax fibre as the reinforcing component and high density polyethylene as the matrix. Acrylic acid pre-treatment was applied to flax fibre to improve the bonding between fibre and polyethylene.

The properties of oil palm fiber were estimated and compared with oil seed flax and industrial hemp fibers. Biocomposite of oil palm fiber and linear low density polyethylene (LLDPE) was manufactured. The effect of fiber size, fiber content and fiber treatment on dimensional stability of the biocomposite was studied. The true density of oil palm fiber is found to be 1503 kg m-₃. The oil palm fibers obtained from field contained nearly one-fourth impurities, and the equilibrium moisture contents (EMC) values of fibers nearly doubled with 25% increase in relative humidity. The dielectric constant of oil palm fiber was in the range of 7.76-8.31. The oil palm fiber resulted in thermograms with two endothermic peaks and three exothermic peaks with the first degradation temperature at 301.71°C. Alkali treatment reduced first degradation temperature to 297.1°C.

Surface temperature and heat flux were measured in a single cylinder SI engine piston when uncoated and with two different surface coatings: a metal TBC and YSZ. Average heat flux into the piston substrate was 33 % higher with the metal TBC and unchanged with the YSZ relative to the uncoated surface. The increase with the metal TBC was attributed to its surface roughness. However, the metal TBC and YSZ reduced peak heat flux into the substrate surface by 69 % and 77 %, respectively.

The removal of soot in the lubricating sumps of diesel engines is a formidable task, further compounded by the introduction of Exhaust Gas Recirculation (EGR). Efficient removal of soot would help ensure engine durability and engine performance while increasing oil drain intervals thus reducing maintenance costs. This paper describes a method by which soot can be separated from the oil with the application of an electric field by utilizing the small electrical charge on the soot particles. The electric field is applied to a network of electrodes that support an open porous network which stabilizes the weakly bound soot cake. Significantly higher filtration efficiency was achieved as compared to mechanical particulate filtration and centrifugation. The paper also discusses the controlling conditions while detailing the performance testing at both a bench scale level and pilot scale level.

The drive to reduce particle emissions from heavy-duty diesel engines has reached the stage where the contribution from the lubricant can have a major impact on the total amount of particulate matter (PM). This paper proposes a model to predict the survival rate (unburnt oil divided by oil consumption) of the hydrocarbons from the lubricant consumed in the cylinder. The input data are oil consumption and cylinder temperature versus crank angle. The proposed model was tuned to correlate well with data from a six-cylinder heavy-duty diesel engine that meets the Euro 5 legislation without exhaust gas aftertreatment. The measured (and modelled) oil survival shows a strong correlation with engine power. The maximum oil survival rate measured (19%) was at motoring conditions at high speed. For this engine, loads above 100 kW yielded an oil survival rate of nearly zero.

Biodiesel-blended fuel is increasingly becoming available for diesel engines. Due to seasonal and economic factors, biodiesel available in filling stations can be sourced from varying feedstocks. Moreover, biodiesel may not contain the minimum oxidative stability required by the time it is used by the automotive consumer. With fuel dilution of engine oil accelerated by post-injection of fuel for regeneration of diesel particulate filters, it is necessary to investigate whether different biodiesel feedstocks or stabilities can affect engine oil properties. In this work, SAE 15W-40 CJ-4 is diluted with B20 fuel, where the B20 was prepared with soy methyl ester (SME) B100 with high Rancimat oxidative stability, SME B100 with low oxidative stability, and lard methyl ester (LME). The oils were then subjected to laboratory aging simulating severe drive cycles. At intermediate aging times, samples were obtained and additional B20 was added to simulate on-going fuel dilution.