Search Results

From 2009 until present Toyota has had a demonstration program of Prius PHV which is comprised of 600 vehicles throughout Japan, Europe and in the US. The vehicles were given to government agencies, corporations, utility companies and private individuals to use. With these demo units Toyota wanted to understand the market reaction and real world impact of plug-in technology on gasoline displacement with increased use of electricity as a fuel. This presentation shows that approximately 50% of fuel was saved using the PHVs in the US. An experiment in Toyota City shows that if public infrastructure is optimized to be convenient and located where people normally park, there is a potential to achieve an ideal fuel savings of 61%. The demonstration program shows that plug-in technology in fact saves fuel and that the proper infrastructure can optimize the fuel savings of plug-in hybrids. Presenter Avernethy Francisco, Toyota

Plug-in Hybrid Electric Vehicles (PHEVs) are entering the market and bring with them new OBD issues. A key one is how to measure in-use monitor performance ratio and where to set a standard for this, as PHEVs will have varying amounts of engine-on operation depending on customer plug-in and driving behavior. Toyota�s Prius PHEV system is described and customer use data from a US demonstration fleet is examined. Some prior denominator proposals by Toyota and CARB are explained, as background for the current CARB/industry agreement for denominator and ratio. Presenter Morton M. Smith, Toyota

The knock metric for controlled auto-ignition (CAI) engines is assessed by considering the physical processes that establish the pressure wave that contributes to the acoustic radiation of the engine, and by analyzing pressure data from a CAI engine. Data sets from the engine operating with port fuel injection, early direct injection and late direct injection are used to monitor the effect of mixture composition stratification. Thermodynamic analysis shows that the local pressure rise produced by heat release has to be discounted by the work spent in acoustic expansion against the ambient pressure to properly predict the pressure wave amplitude. Based on this analysis, a modified correlation between the pressure wave amplitude and the maximum pressure rise rate (MPRR) is developed by introducing an MPRR offset to account for the expansion work.

The engine and its exhaust flow behaviors are investigated in a turbo-charged gasoline direct injection engine under simulated cold-fast-idle condition. The metrics of interest are the exhaust sensible and chemical enthalpy flows, and the exhaust temperature, all of which affect catalyst light off time. The exhaust sensible enthalpy flow is mainly a function of combustion phasing; the exhaust chemical enthalpy flow is mainly a function of equivalence ratio. High sensible and chemical enthalpy flow with acceptable engine stability could be obtained with retarded combustion and enrichment. When split injection is employed with one early and one later and smaller fuel pulse, combustion retards with early secondary injection in the compression stroke but advances with late secondary injection. Comparing gasoline to E85, the latter produces a lower exhaust temperature because of charge cooling effect and because of a faster combustion.

National concerns over energy consumption and emissions from the transportation sector have prompted regulatory agencies to implement aggressive fuel economy targets for light-duty vehicles through the U.S. National Highway Traffic Safety Administration/Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) program. Automotive manufacturers have responded by bringing competitive technologies to market that maximize efficiency while meeting or exceeding consumer performance and comfort expectations. In a collaborative effort among Toyota Motor Corporation, Argonne National Laboratory (ANL), and the National Renewable Energy Laboratory (NREL), the real-world savings of one such technology is evaluated. A commercially available Toyota Highlander equipped with two-phase cold storage technology was tested at ANL’s chassis dynamometer testing facility.

The effects of secondary air on the exhaust oxidation of particulate matters (PM) have been assessed in a direct-injection-spark-ignition engine under fuel rich fast idle condition (1200 rpm; 2 bar NIMEP). Substantial oxidation of the unburned feed gas species (CO and HC) and significant reduction of both the particulate number (up to ∼80%) and volume (up to ∼90%) have been observed. The PM oxidation is attributed to the reactions between the PM and the radicals generated in the oxidation of the feed gas unburned species. This hypothesis is supported by the observation that the reduction in PM volume is proportional to the amount of heat release in the secondary oxidation.

Passenger cars in the United States continue to incorporate increasing levels of technology and features. However, deployment of technology requires substantial development and time in the automotive sector. Prior analyses indicate that deployment of technology in the automotive sector can be described by a logistic function. These analyses refer to maximum annual growth rates as high as 17% and with developmental times of 10-15 years. However, these technologies vary widely in complexity and function, and span decades in their implementation. This work applies regression with a logistic form to a wide variety of automotive features and technologies and, using secondary regression, identifies broader trends across categories and over time.

For urea Selective Catalytic Reduction (SCR) systems, adaptive control is of interest to provide a capability of maintaining high NOx conversion efficiency and low ammonia slip in the presence of uncertainties in the system. In this paper, the dynamics of the urea SCR system are represented by a control-oriented model which is based on a linear transfer function, with parameters dependent on engine operating conditions. The parameters are identified from input-output data generated by a high fidelity full chemistry model of the urea SCR system. The use of the full chemistry model facilitated the representation of the dynamics of stored ammonia (not a directly measurable parameter) as well as post SCR NOx and ammonia slip. A closed-loop Proportional-plus-Integral (PI) controller was first designed using the estimate of stored ammonia as a feedback signal.

Transport policy research seeks to predict and substantially reduce the future transport-related greenhouse gas emissions and fuel consumption to prevent negative climate change impacts and protect the environment. However, making such predictions is made difficult due to the uncertainties associated with the anticipated developments of the technology and fuel situation in road transportation, which determine the total fuel use and emissions of the future light-duty vehicle fleet. These include uncertainties in the performance of future vehicles, fuels' emissions, availability of alternative fuels, demand, as well as market deployment of new technologies and fuels. This paper develops a methodology that quantifies the impact of uncertainty on the U.S. transport-related fuel use and emissions by introducing a stochastic technology and fleet assessment model that takes detailed technological and demand inputs.

Loping, defined here as skipping without a foot exchange, is a gait uncommonly used by humans on Earth, but favored by Apollo astronauts during lunar surface excursions. Astronauts may have adopted loping due to space suit-imposed mobility restrictions or because of a possible stability advantage conferred by a relatively constant and wide support base. To evaluate whether loping confers metabolic advantages we monitored ten subjects during loping and running, simulating reduced gravity via partial body suspension, and simulating suited conditions using a lower body exoskeleton. In lunar gravity, loping incurred lower metabolic costs than running for every subject; loping, while efficient at low gravity levels, was less efficient than running in Earth gravity.

The SAE FCV Safety Working Group has been addressing fuel cell vehicle (FCV) safety for over 7 years. The initial document, SAE J2578, was published in 2002. SAE J2578 has been valuable to the FCV development with regard to the identification of hazards and the definition of countermeasures to mitigate these hazards such that FCVs can be operated in the same manner as conventional gasoline IC-powered vehicles. The document is currently being updated to clarify and update requirements so that the document will continue to be relevant and useful in the future. In addition to developing draft revisions to SAE J2578, the working group has updated SAE J1766 and is developing a new recommended practice on vehicular hydrogen systems (SAE J2579). The documents are written from the standpoint of systems-level, performance-based requirements. A risk-based approach was used to identify potential electrical and fuel system hazards and provide criteria for acceptance.

In this paper, the claim is that the information available in the passenger vehicle can be viewed as biased towards entertainment as opposed to vehicle handling. To support this claim, I discuss first a simplified description of driving behavior: street driving can be thought of as a highly complex task comprising two principal aspects: vehicle control (VC) and everything else (EE). I then propose ways to adjust the information bias of the vehicle in favor of VC and discuss concrete examples of work: vehicle control gauges, rear speed display and the ESX-2 Concept Car. However, my view is that the information bias problem is not so much a "technology" problem as it is a "knowledge" problem. The vehicle control aspect of street driving appears inadequately respected and, consequently, inadequately articulated.

Toyota and BP have performed a collaborative study to understand the impact of fuel composition on the combustion and emissions of a prototype 1.8L lean boosted engine. The fuel matrix was designed to understand better the impact of a range of fuel properties on fundamental combustion characteristics including thermal efficiency, combustion duration, exhaust emissions and extension of lean limit. Most of the fuels in the test matrix were in the RON range of 96 - 102, although ethanol and other high octane components were used in some fuels to increase RON to the range 104 - 108. The oxygen content ranged from 2 - 28%, and constituents included biocomponents, combustion improving additives and novel blend components. Performance and emissions tests were conducted over a range of engine operating conditions. Thermal efficiency was mapped at stoichiometric and lean conditions, and the limit of lean combustion was established for different fuels.

This paper reports on the Thermal Control System (TCS) of the AMS-02 (Alpha Magnetic Spectrometer). AMS-02 will be installed on the International Space Station (ISS) Starboard segment of the Truss in 2005, where it will acquire data for at least three years. The AMS-02 payload has a mass of about 6700 kg, a power budget of 2kW and consists of 5 different instruments, with their associated electronic equipment. Analytical integration of the AMS-02 thermal mathematical model is described in the paper, together with the main thermal design features. Stringent temperature stability requirements have been satisfied, providing a stable thermal environment that allows for easier calibration of the detectors. The overall thermal design uses a combination of standard and innovative concepts to fit specific instruments needs.

In recent years, engine control systems have become more and more complex because of the growing pressure to develop technical innovations due to social pressures such as global warming and the depletion of fossil fuels. On the other hand, products must be launched on the market in a timely manner and at low cost. For these reasons, calibration processes have become more sophisticated. It is possible to improve the efficiency of calibration by making good use of models, and a calibration process that incorporates models is called model based calibration (MBC). MBC is a valid means of reducing the number of measurement points to some extent by statistical engine modeling and design of experiment (DoE) methodology which places measurement points in order to maximize modeling accuracy. However, it is still necessary to spend much time carrying out boundary detection testing before DoE.

An ignition delay correlation encompassing the effects of temperature, pressure, residual gas, EGR, and lambda (on both the rich and lean sides) has been developed. The procedure uses the individual knocking cycle data from a boosted direct injection SI engine (GM LNF) operating at 1250 to 2000 rpm, 8-14 bar GIMEP, EGR of 0 to 12.5%, and lambda of 0.8 to 1.3 with a certification fuel (Haltermann 437, with RON=96.6 and MON=88.5). An algorithm has been devised to identify the knock point on individual pressure traces so that the large data set (of some thirty three thousand cycles) could be processed automatically. For lean and for rich operations, the role of the excess fuel, air, and recycled gas (which has excess air in the lean case, and hydrogen and carbon monoxide in the rich case) may be treated effectively as diluents in the ignition delay expression.

The loss mechanisms associated with engine downsizing, boosting and compression ratio change are assessed. Of interest are the extents of friction loss, pumping loss, and crevice loss. The latter does not scale proportionally with engine size. These losses are deconstructed via a cycle simulation model which encompasses a friction model and a crevice loss model for engine displacement of 300 to 500 cc per cylinder. Boost pressure is adjusted to yield constant torque. The compression ratio is varied from 8 to 20. Under part load, moderate speed condition (1600 rpm; 13.4 Nm/cylinder brake torque), the pumping work reduces significantly with downsizing while the work loss associated with the crevice volume increases. At full load (1600 rpm; 43.6 Nm/cylinder brake torque), the pumping work is less significant. The crevice loss (normalized to the fuel energy) is essentially the same as in the part load case. The sensitivities of the respective loss terms to downsizing are reported.

This paper focuses on the development of the centralized air flow system S-FLOW (Energy Saving Air Flow Control System). The S-FLOW system directs thermal energy to each seating position in the vehicle based on occupancy, thus prioritizing the energy usage based on the particular scenario. The thermal environment in a vehicle's cabin is non-uniform. If the climate control system is used to direct airflow exclusively to any one region of the cabin, without special considerations, comfort may be adversely impacted. To solve this concern, a non-uniform evaluation method was developed to evaluate comfort at each body region of the occupant using the SET* (Standard new effective temperature) method. SET* is a parameter that combines the effects of temperature, airflow velocity, humidity, and other parameters to quantify thermal comfort. Next, a method was established that correlated each body region's SET* value to the occupant's overall thermal comfort.

A model which converts flame arrival times at a head gasket ionization probe, used in a spark-ignition engine, into flame contours has been developed. The head gasket was manufactured at MIT using printed circuit board techniques. It has eight electrodes symmetrically spaced around the circumference (top of cylinder liner) and it replaces the conventional head gasket. The model is based on engine flame propagation rate data taken from the literature. Data from optical studies of S.I. engine combustion or studies utilizing optical fiber or ionization probe diagnostics were analyzed in terms of the apparent flame speed and the entrainment speed (flame speed relative to the fluid ahead of the flame). This gives a scaling relationship between the flame speed and the mass fraction burned which is generic and independent of the chamber shape.

As greater emphasis is placed on the development of small fuel-efficient cars, there is a growing need to reduce the size of the inverter used in hybrid vehicles (HVs). However, semiconductor devices and other components are generating larger amounts of heat and the parts used to cool these components are becoming thinner. One issue resulting from these trends is perforations that propagate from coolant paths. This development secured corrosion resistance by controlling sacrificial corrosion protection performance, optimizing the use of Mn and Si materials to reduce susceptibility to grain-boundary corrosion, and taking a microstructural approach to the flow of the brazing filler metal. The developed material was applied to the inverter cooler of a small HV released at the end of 2011.