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This paper proposes a technology to reduce vehicle surge during towing that utilizes motors and shifting to help ensure comfort in a parallel HEV pickup truck. Hybridization is one way to reduce fuel consumption and help realize carbon neutrality. Parallel HEVs have advantages in the towing, hauling, and high-load operations often carried out by pickup trucks, compared to other HEV systems. Since the engine, motor, torque converter, and transmission are connected in series in a parallel HEV, vehicle surge may occur when the lockup clutch is engaged to enhance fuel efficiency, similar to conventional powertrains. Vehicle surge is a low-frequency vibration phenomenon. In general, the source is torque fluctuation caused by the engine and tires, with amplification provided by first-order torsional driveline resonance, power plant resonance, suspension resonance, and cabin resonance. This vibration is amplified more during towing.

The dash mat is one of the most important acoustic components in the vehicle for both powertrain noise and road noise attenuation. To optimize acoustic performance and mass requirements in the advanced development stage, analytical modeling is essential. The development of a detailed Statistical Energy Analysis (SEA) model of a dash mat is discussed in this paper. Modeling techniques and correlation with test are presented for two different production dash mat designs, a barrier-decoupler conventional system and a dual layer dissipative system without a mass barrier. The material properties and thickness distribution are used in the SEA model together with the geometry information of the dash panel. With the SEA model suitably correlated, trade-off studies are conducted to investigate the relationship between mass reduction of the barrier and change in decoupler thickness. The effects of air gaps are also considered in both modeling and testing.

High fuel efficiency and low emission technologies, such as Direct Injection (DI) gasoline and diesel engines and hybrid powertrains, have been developed to resolve environmental and energy resource issues. The hybrid powertrain system has achieved superior power performance as well as higher system efficiency and is expected to be a core powertrain technology because it is compatible with various power sources including fuel cells. It becomes important to control complicated hybrid systems that consist of not only a powertrain but also vehicle systems such as regenerative braking. Model-based control and calibration enables both control strategy optimization and control system development efficiency improvement.

The renewed platform of the upcoming flagship front-engine, rear-wheel drive (FR) vehicles demands high levels of driving performance, fuel efficiency and noise-vibration performance. The newly developed driveline system must balance these conflicting performance attributes by adopting new technologies. This article focuses on several technologies that were needed in order to meet the demand for noise-vibration performance and fuel efficiency. For noise-vibration performance, this article will focus on propeller shaft low frequency noise (booming noise). This noise level is determined by the propeller shaft’s excitation force and the sensitivity of differential mounting system. In regards to the propeller shaft’s excitation force, the contribution of the axial excitation force was clarified. This excitation force was decreased by adopting a double offset joint (DOJ) as the propeller shaft’s second joint and low stiffness rubber couplings as the first and third joints.

New engine controls have been developed for the turbocharged Lexus NX200t to improve driving power by reducing engine torque output lag. Drive power management functions have been centralized in an integrated drive power control system. The newly developed controls minimize the potential reduction in drivability associated with the adoption of a turbocharged engine while improving fuel efficiency. General driveability issues commonly associated with a turbocharged engine include sudden increases in drive power due to the response lag of the turbocharger, and higher shifting frequencies if this response lag triggers a disturbed accelerator operation pattern by the driver. The developed technologies detect and control sudden increases in drive power to create the optimum drive power map, and reduce unnecessary shifts even if the driver's accelerator operation is disturbed.

The engine in the new fourth generation Prius carries over the same basic structure as the 2ZR-FXE used in the third generation and incorporates various refinements to enhance fuel efficiency. Called the ESTEC 2ZR-FXE, the new engine incorporates various fuel efficient technologies to improve combustion characteristics, knocking, and heat management, while also reducing friction. As a result of this meticulous approach to enhancing fuel efficiency, the new engine is the first gasoline engine in the world to achieve a maximum thermal efficiency of 40%. This paper describes the fuel efficient technologies incorporated into this engine.

Recently, global warming and energy security have received significant attention. Thus an improvement of the vehicle fuel economy is strongly required. For engines, one effective way is to improve the engine thermal efficiency. Raising compression ratio [1] or turbo charging technologies have potential to achieve high thermal efficiency. However knock does not allow the high thermal efficiency. Knock depends on the fuel composition and the pressure and temperature history of unburnt end-gas [2-3]. For fuels, RON is well known for describing the anti knock quality. High RON fuels have high anti knock quality and result in higher thermal efficiency. This paper investigates the impact of high RON fuels on the thermal efficiency by using high compression ratio engine, turbo charged engine, and lean boosted engine [4]. Finally, it is shown that the high thermal efficiency can be approached with high RON gasoline and ethanol.

Introducing effective technologies to reduce carbon emissions in the transport sector is a critical issue for automotive manufacturers to contribute to sustainable development. Unlike the plug-in electric vehicles (PEVs), whose effectiveness is dependent on the carbon intensity of grid electricity, the solar hybrid vehicle (SHV) can be an alternative electric vehicle because of its off-grid, zero-emission electric technology. Its usability is also advantageous because it does not require manual charging by the users. This study aims at evaluating the economic, environmental, and usability benefits of SHV by comparing it with other types of vehicles including PEVs. By setting cost and energy efficiency on the basis of the assumed technology level in 2030, annual cost and annual CO2 emissions of each vehicle are calculated using the daily mileage pattern obtained from a user survey of 5,000 people in Japan and the daily radiation data for each corresponding user.

Managing (minimizing and optimizing) the total mass of a vehicle is recognized as a critical task during the development of a new vehicle, as well as throughout its production lifecycle. This paper summarizes a literature review of, and investigation into, the strategies, methods and best practices for achieving low total mass in new vehicle programs, and/or mass reductions in existing production vehicle programs. Empirical and quantitative data and examples from the automotive manufacturers and suppliers are also provided in support of the material presented.

In recent years, climate protection has become as important as ozone layer protection was in the late 1980's and early 1990s. Concerns about global warming and climate change have culminated in the Kyoto Protocol, a treaty requiring its signatories to limit their total emission of greenhouse gases to pre-1990 levels by 2008. The inclusion of hydrofluorocarbons (HFCs) as one of the controlled substances in the Kyoto Protocol has increased global scrutiny of the global warming impact of HFC-134a (called R-134a when used as a refrigerant), the current mobile air conditioning refrigerant. Industry's first response was to begin improving current R-134a systems to reduce leakage, reduce charge, and increase system energy efficiency, which in turn reduces tailpipe CO2 emissions. An additional option would be to replace the current R-134a with a refrigerant of lower global warming impact. This paper documents the use of another HFC, R-152a, in a mobile A/C system.

In an effort to reduce mass, future automotive bodies will feature lower gage steel or lighter weight materials such as aluminum. An unfortunate side effect of lighter weight bodies is a reduction in sound transmission loss (TL). For barrier based systems, as the total system mass (including the sheet metal, decoupler, and barrier) goes down the transmission loss is reduced. If the reduced surface density from the sheet metal is added to the barrier, however, performance can be restored (though, of course, this eliminates the mass savings). In fact, if all of the saved mass from the sheet metal is added to the barrier, the TL performance may be improved over the original system. This is because the optimum performance for a barrier based system is achieved when the sheet metal and the barrier have equal surface densities. That is not the case for standard steel constructions where the surface density of the sheet metal is higher than the barrier.

Turbocharged downsized gasoline engines have been widely used in the market as one of the measures to improve fuel economy. Coking phenomena in the lubricating circuit of the turbocharger unit is a well-known issue that may affect turbocharger efficiency and durability. Laboratory rig test such as ASTM D6335 (TEOST 33C) has been used to predict this phenomenon as a part of engine oil performance requirements. On the other hand, laboratory tests sometimes have difficulty reproducing the actual mechanism of coking caused by engine oil degradation. Accumulation of insoluble material is one of the important gasoline engine oil degradation modes. The influence of temperature and insoluble concentration were investigated based on actual used engine oils collected in the field.

The focus of this research effort was to develop a technique to measure the cyclic variability of the mass injected by fuel injectors. Successful implementation of the measurement technique introduced in this paper can be used to evaluate injectors and improve their designs. More consistent and precise fuel injectors have the potential to improve fuel efficiency, engine performance, and reduce emissions. The experiments for this study were conducted at the Michigan State University Automotive Research Experiment Station. The setup consists of a fuel supply vessel pressurized by compressed nitrogen, a Dantec laser Doppler anemometry (LDA) system to measure the centerline velocity of fuel, a quartz tube for optical access, and a Cosworth IC 5460 to control the injector. The detector on the LDA system is capable of resolving Doppler bursts as short as 6μs, depending on the level of seeding, thus giving a detailed time/velocity profile.

Thermal load caused by engine combustion is one of the important issues for the engines such as high-boosted downsized engines and engines with high compression ratio. In particular, it is necessary to maintain the reliability and durability of exhaust valves which are subject to the biggest thermal impact. For this reason, sodium filled hollow valves are utilized in preference to solid valves in order to decrease the exhaust valve temperature. The most common method for detecting the valve temperature is to estimate the temperature by measuring hardness on valve surface (Hardness test). However, the hardness test is only applicable to the condition up to 800°C. Therefore, this paper presents new techniques for measuring the temperature for sodium-filled valve using infrared thermography and thermocouple as an alternative hardness test. The authors also examined the valve temperatures at a variety of engine speeds and cooling of the sodium-filled valve during engine operation.

The vehicle air-conditioning system has significant impact on fuel economy and range of electric vehicles. Improving the fuel economy of vehicles therefore demand for energy efficient climate control systems. Also the emissions regulations motivate the reduced use of fuel for vehicle's cabin climate control. Solar heat gain of the passenger compartment by greenhouse effect is generally treated as the peak thermal load of the climate control system. Although the use of advanced glazing is considered first to reduce solar heat gain other means such as ventilation of parked car and recirculation of cabin air also have impetus for reducing the climate control loads.

When hydrogen is added to a gasoline fueled spark ignition engine the lean limit of the engine can be extended. Lean running engines are inherently more efficient and have the potential for significantly lower NOx emissions. In the engine concept examined here, supplemental hydrogen is generated on-board the vehicle by diverting a fraction of the gasoline to a plasmatron where a partial oxidation reaction is initiated with an electrical discharge, producing a plasmatron gas containing primarily hydrogen, carbon monoxide, and nitrogen. Two different gas mixtures were used to simulate the plasmatron output. An ideal plasmatron gas (H2, CO, and N2) was used to represent the output of the theoretically best plasmatron. A typical plasmatron gas (H2, CO, N2, and CO2) was used to represent the current output of the plasmatron. A series of hydrogen addition experiments were also performed to quantify the impact of the non-hydrogen components in the plasmatron gas.

Reducing the loss of the power control unit (PCU) in a hybrid vehicle (HV) is an important part of improving HV fuel efficiency. Furthermore the loss of power devices (insulated gate bipolar transistors (IGBTs) and diodes) used in the PCU must be reduced since this amounts to approximately 20% of the total electrical loss in an HV. One of the issues for reducing loss is the trade-off relationship with reducing voltage surge. To restrict voltage surge, it is necessary to slow down the switching speed of the IGBT. In contrast, the loss reduction requires the high speed switching. One widely known method to improve this trade-off relationship is to increase the gate voltage in two stages. However, accurate and high-speed operation of the IGBT gate control circuit is difficult to accomplish. This research clarifies a better condition of the two-stage control and designed a circuit that improves this trade-off relationship by increasing the speed of feedback control.

Multi-cylinder hydrogen-absorbing alloy tanks for fuel cell vehicles have 10 to 40 metallic cylinders that are bundled and filled with hydrogen-absorbing alloy. In this system, the cylinders themselves act as a heat exchanger and the working pressure is lowered to 10 to 20 MPa compared with high-pressure MH tanks. Moreover, both heat conduction and mass reduction can be achieved by reducing the wall thickness of the cylinders. A model verification experiment was conducted using a one-quarter-scale prototype of a full size tank, and a conduction simulation model verified in the experiment was used to predict the performance of the full size tank. Results showed that it is possible to fill the tank with hydrogen to 80% of its capacity in a five-minute filling time, although issues related to heat conductivity performance require improvement. Accordingly, it may be possible to adopt this tank as part of a system if the storage amount of the hydrogen-absorbing alloy can be increased.

An SAE 5W-20 ILSAC GF-2 gasoline engine oil, which improves vehicle fuel efficiency by more than 1.5% relative to conventional SAE 5W-30 gasoline engine oils, was newly developed. And the target that 1.5% fuel efficiency improvement remains more than 10,000km was also achieved. The viscosity of this oil was optimized to satisfy both fuel economy and anti-wear performances. MoDTC and thiadiazole were added to achieve the target.

Spark ignition direct injection (SIDI) engines have the potential to realize significant thermal efficiency improvements compared to conventional port fuel injection engines. The effects of fuel properties on efficiency and emissions have been investigated in a prototype of an Avensis Wagon equipped with a 2.0 liter, 4 cylinder spark ignition, direct injection (SIDI) engine designed to meet US 2000 emission standards. The vehicle employed a close coupled three-way catalyst and a NOx storage and reduction catalyst. Seven matrix fuels were blended to the same RON with varying levels of aromatics, olefins, ethanol, and volatility. Relative thermal efficiency, fuel economy, and tailpipe emissions were measured for the matrix fuels and a base fuel under the FTP LA4 driving cycle. The engine was operated in a lean burn mode in light load condition for approximately half of the driving cycle.