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Toyota's Comprehensive Environmental Technology: Providing Choices for Sustainable Mobility

2011-11-04
In the pursuit of a sustainable transportation systems, Toyota is considering a comprehensive approach pursuing multiple advanced technologies to address three primary issues: GHG, Petroleum Use, and Air Quality. Vehicles must be ready for and affordable to the mass market to provide the customer choices to meet their transportation needs whether it is EV's, Hybrids, Plug-In Hybrids or Fuel Cell Hydrogen Hybrids. Our studies have shown that EVs have the potential to provide significant improvements in energy utilization especially combined with other advanced technologies. Toyota believes that a combination of these technolgies will provide complementary solution that enables a sustainable transportation system. Presenter Takehito Yokoo, Toyota Motor Corporation
Journal Article

Low Emissions and High-Efficiency Diesel Combustion Using Highly Dispersed Spray with Restricted In-Cylinder Swirl and Squish Flows

2011-04-12
2011-01-1393
A new clean diesel combustion concept has been proposed and its excellent performance with respect to gas emissions and fuel economy were demonstrated using a single cylinder diesel engine. It features the following three items: (1) low-penetrating and highly dispersed spray using a specially designed injector with very small and numerous orifices, (2) a lower compression ratio, and (3) drastically restricted in-cylinder flow by means of very low swirl ports and a lip-less shallow dish type piston cavity. Item (1) creates a more homogeneous air-fuel mixture with early fuel injection timings, while preventing wall wetting, i.e., impingement of the spray onto the wall. In other words, this spray is suitable for premixed charge compression ignition (PCCI) operation, and can decrease both nitrogen oxides (NOx) and soot considerably when the utilization range of PCCI is maximized.
Technical Paper

Development of Low Pressure Loop EGR System for Diesel Engines

2011-04-12
2011-01-1413
Low pressure loop (LPL) EGR systems are effective means of simultaneously reducing the NOx emissions and fuel consumption of diesel engines. Further lower emission levels can be achieved by adopting a system that combines LPL EGR with a NOx storage and reduction (NSR) catalyst. However, this combined system has to overcome the issue of combustion fluctuations resulting from changes in the air-fuel ratio due to EGR gas recirculation from either NOx reduction control or diesel particulate filter (DPF) regeneration. The aim of this research was to reduce combustion fluctuations by developing LPL EGR control logic. In order to control the combustion fluctuations caused by LPL EGR, it is necessary to estimate the recirculation time. First, recirculation delay was investigated. It was found that recirculation delay becomes longer when the LPL EGR flow rate or engine speed is low.
Technical Paper

New Drivetrain for Toyota's Flagship Lexus LFA Sports Car

2011-04-12
2011-01-1427
Toyota Motor Corporation has developed a new drivetrain for their flagship Lexus LFA sports car. Passionate driving experience was pursued at the forefront of development. Superior vehicle performance, handling, and responsiveness that seem to anticipate the driver's intentions are achieved. Special vehicle packaging and component placement are adopted in the LFA in order to realize such performance. The engine, clutch, and front counter gear are positioned at the front of the vehicle, and the transaxle at the rear. The engine and transaxle are connected by a rigid torque tube. The transaxle is an automated manual transmission equipped with an electrohydraulic actuator for controlling both the shift and clutch operations. This actuator enables accurate control of the transmission and extremely quick response to shift paddle operation by the driver. This paper describes a general outline of the drivetrain and each component that has significantly contributed to LFA product appeal.
Journal Article

Development of iQ with CVT for USA

2011-04-12
2011-01-1425
TOYOTA has developed the iQ with a 1.3L engine for the Scion brand in USA. Due to the importance of fun-to-drive factor for the Scion brand image, a responsive driving performance is required even with compact packaging and a small engine. In addition, because of the recent attention to global-warming and energy issues on a global scale, development of vehicles with high fuel economy is one of the most important issues for a car manufacturer. Therefore, it is necessary for a vehicle to have both high driving performance and fuel economy. TOYOTA has adopted the CVT-i as the transmission for this purpose. The following were achieved by adopting the CVT-i as the transmission for the iQ(1.3L). 1 Responsive driving performance with shift changes without a time lag. 2 Compact transmission for efficient vehicle packaging 3 Class-leading fuel economy performance. Moreover, it was developed with adjustments for the US market by improving the shift schedule for a linear acceleration feel.
Technical Paper

CAE Methodology for Optimizing NVH, Functional Reliability, and Mass Reduction at Engine Concept Design Phase

2011-05-17
2011-01-1511
Due to the global economic downturn and higher environmental awareness, the social demands for low cost and fuel efficient vehicles are increasing. At the same time the engine power is increasing and customer expectations of reliability and NVH levels are increasing. To meet all the requirements, engineers are challenged to design light weight parts with higher performance. However, unconsidered mass reduction carries a risk of compromised NVH, Functional Reliability, and other functional demands. In order to resolve this contradiction, it is important to establish a basic structure with minimum necessary mass at the concept design phase, when there are still many degrees of freedom in the design space. Hence, a multi-objective optimization CAE methodology applicable for designing the basic structure of the Engine system was developed and is detailed below.
Technical Paper

Three-Dimension Deposited Soot Distribution Measurement in Silicon Carbide Diesel Particulate Filters by Dynamic Neutron Radiography

2011-04-12
2011-01-0599
Exhaust emissions are well known to have adverse impacts on human health. Studies have demonstrated that there is an association between ambient particulate matter (PM) levels and various harmful cardiopulmonary conditions. Soot exhaust from diesel engines can be a significant contributor to airborne pollutants. A key component in PM level control for a diesel engine is a diesel particulate filter (DPF). This device traps soot while allowing other exhaust gases to pass unhindered. However, the performance of diesel particulate filters can change with increasing soot loadings and thus may require regeneration or replacement. Improved understanding of diesel particulate filters is dependent upon the knowledge of the actual soot loading and the soot distribution within the DPF. Neutron radiography (NR) has been identified as an effective means of non-destructively identifying hydrogen or carbon adsorbed in PM.
Journal Article

Method for Estimating Time to Collision at Braking in Real-World, Lead Vehicle Stopped Rear-End Crashes for Use in Pre-Crash System Design

2011-04-12
2011-01-0576
This study presents a method for determining the time to collision (TTC) at which a driver of the striking vehicle in a real-world, lead vehicle stopped (LVS) rear-end collision applied the brakes. The method employs real-world cases that were extracted from the National Automotive Sampling System / Crashworthiness Data System (NASS / CDS) years 2000 to 2009. Selected cases had an Event Data Recorder (EDR) recovered from the striking vehicle that contained pre-crash vehicle speed and brake application. Of 59 cases with complete EDR records, 12 cases (20%) of drivers appeared not to apply the brakes at all prior to the collision. The method was demonstrated using 47 rear-end cases in which there was driver braking. The average braking deceleration for those cases with sufficient vehicle speed information was found to be 0.52 g's. The average TTC that braking was initiated at was found to vary in the sample population from 1.1 to 1.4 seconds.
Journal Article

Development of Test Method to Evaluate Aggressiveness Focusing on Stiffness and Interaction: Part 2

2011-04-12
2011-01-0547
Test methods to evaluate vehicle compatibility are being studied worldwide. Compatibility performance is central in securing mutual protection in collisions between large and small vehicles. To consider compatibility performance, good structural interaction and stiffness matching are important. A test method using a novel moving deformable barrier (MDB) was developed to evaluate compatibility performance that includes consideration of both structural interaction and stiffness matching. This new barrier has the following features to represent an offset vehicle-to-vehicle collision with a compact car. The barrier width is divided at the lower rail position of the compact car, and the layer that simulates the characteristics of vehicle sections toward the interior is harder than the outward layer. This varying stiffness of the MDB helps simulate the horizontal interaction performance that occurs in real-world crashes.
Technical Paper

Utilization of Finite Element Analysis to Develop Automotive Components

2010-10-06
2010-36-0004
The finite element method (FEM) is used daily in the automotive industry for such purposes as reducing the time of product development and improving the design based on analysis results, followed by later validation by tests in the laboratory and on the proving ground. This paper will present some of the methodology used to develop automotive components by finite element analysis, including procedures to specialize FEM models to obtain quantitative and qualitative results for systems such as body, chassis, and suspension components, as well as validation of the models by experimental data.
Journal Article

Development of Electric Power Control using the Capacitance Characteristics of the Fuel Cell

2011-04-12
2011-01-1346
Cold weather operation has been a major issue for fuel cell vehicles (FCV). In order to counteract this effect on FCV operation, an approach for rapid warm-up operation based on : concentration overvoltage increase and conversion efficiency decrease by limiting oxygen or hydrogen supply, was adopted in a running fuel cell hybrid vehicle. In order to adjust the output power response of the fuel cell to the target power of the vehicle, -the inherent capacitance characteristics of the fuel cell were measured- based on the oxidation-reduction reaction and an electric double-layer capacitor, and an equivalent electric circuit model of a fuel cell with the capacitance was constructed. This equivalent electric circuit model was used to develop a power control algorithm to manage absorption of the surplus power, or deviation, to the capacitance.
Technical Paper

Rapid Boundary Detection for Model Based Diesel Engine Calibration

2011-04-12
2011-01-0741
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.
Technical Paper

Study on Squeeze Mode Magneto-Rheological Engine Mount with Robust H-Infinite Control

2011-04-12
2011-01-0757
Magneto-rheological fluid squeeze mode investigations at CVeSS have shown that MR fluids show large force capabilities in squeeze mode. A novel MR squeeze mount was designed and built at CVeSS, and a dynamic mathematical model was developed, which considered the inertial effect and was validated by the test data. A variant engine mount that will be used for isolating vibration, based on the MR squeeze mode is proposed in the paper. The mathematical governing equations of the mount are derived to account for its operation with MR squeeze mode. The design method of a robust H✓ controller is addressed for the squeeze mount subject to parameter uncertainties in the damping and stiffness. The controller parameter can be derived from the solution of bilinear matrix inequalities (BMIs). The displacement transmissibility is constrained to be no more than 1.05 with this robust H✓ controller. The MR squeeze mount has a very large range of force used to isolate the vibration.
Technical Paper

Development of Toyota Plug-In Hybrid System

2011-04-12
2011-01-0874
Toyota has been introducing several hybrid vehicles (HV) as a countermeasure to concerns related to the automotive mobility like CO2 reduction, energy security, and emission reduction in urban areas. A next step towards an even more effective solution for these concerns is a plug-in hybrid vehicle (PHV). This vehicle combines the advantages of electric vehicles (EV), which can use clean electric energy, and HV with it's high environmental potential and user-friendliness comparable to conventional vehicles such as a long cruising range. This paper describes a newly developed plug-in hybrid system and its vehicle performance. This system uses a Li-ion battery with high energy density and has an EV-range within usual trip length without sacrificing cabin space. The vehicle achieves a CO2 emission of 59g/km and meets the most stringent emission regulations in the world. The new PHV is a forerunner of the large-scale mass production PHV which will be introduced in two years.
Technical Paper

A Study of Driver Injury Mechanism in High Speed Lateral Impacts of Stock Car Auto Racing Using a Human Body FE Model

2011-04-12
2011-01-1104
This paper analyzed the mechanisms of injury in high speed, right-lateral impacts of stock car auto racing, and interaction of the occupant and the seat system for the purpose of reducing the risk of injury, primarily rib fractures. Many safety improvements have been made to stock car racing recently, including the Head and Neck Support devices (HANS®), the 6-point restraint harnesses, and the implementation of the SAFER Barrier. These improvements have contributed greatly to mitigating injury during the race crash event. However, there is still potential to improve the seat structure and the understanding of the interaction between the driver and the seat in the continuation of making racing safety improvements. This is particularly true in the case of right-lateral impacts where the primary interaction is between the seat supports and the driver and where the chest is the primary region of injury.
Technical Paper

An Extended-Range Electric Vehicle Control Strategy for Reducing Petroleum Energy Use and Well-to-Wheel Greenhouse Gas Emissions

2011-04-12
2011-01-0915
The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is participating in the 2008 - 2011 EcoCAR: The NeXt Challenge Advanced Vehicle Technology Competition series organized by Argonne National Laboratory (ANL) and sponsored by General Motors (GM) and the U.S. Department of Energy (DoE). Following GM's vehicle development process, HEVT established goals that meet or exceed the competition requirements for EcoCAR in the design of a plug-in, range-extended hybrid electric vehicle. The challenge involves designing a crossover SUV powertrain to reduce fuel consumption, petroleum energy use and well-to-wheels (WTW) greenhouse gas (GHG) emissions. In order to interface with and control the vehicle, the team added a National Instruments (NI) CompactRIO (cRIO) to act as a hybrid vehicle supervisory controller (HVSC).
Technical Paper

Development and Validation of an E85 Split Parallel E-REV

2011-04-12
2011-01-0912
The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is participating in the 2009 - 2011 EcoCAR: The NeXt Challenge Advanced Vehicle Technology Competition series organized by Argonne National Lab (ANL), and sponsored by General Motors Corporation (GM), and the U.S. Department of Energy (DOE). Following GM's Vehicle Development Process (VDP), HEVT established team goals that meet or exceed the competition requirements for EcoCAR in the design of a plug-in extended-range hybrid electric vehicle. The competition requires participating teams to improve and redesign a stock Vue XE donated by GM. The result of this design process is an Extended-Range Electric Vehicle (E-REV) that uses grid electric energy and E85 fuel for propulsion. The vehicle design is predicted to achieve an SAE J1711 utility factor corrected fuel consumption of 2.9 L(ge)/100 km (82 mpgge) with an estimated all electric range of 69 km (43 miles) [1].
Journal Article

Calibration and Validation of a Diesel Oxidation Catalyst Model: from Synthetic Gas Testing to Driving Cycle Applications

2011-04-12
2011-01-1244
To meet future stringent emission regulations such as Euro6, the design and control of diesel exhaust after-treatment systems will become more complex in order to ensure their optimum operation over time. Moreover, because of the strong pressure for CO₂ emissions reduction, the average exhaust temperature is expected to decrease, posing significant challenges on exhaust after-treatment. Diesel Oxidation Catalysts (DOCs) are already widely used to reduce CO and hydrocarbons (HC) from diesel engine emissions. In addition, DOC is also used to control the NO₂/NOx ratio and to generate the exothermic reactions necessary for the thermal regeneration of Diesel Particulate Filter (DPF) and NOx Storage and Reduction catalysts (NSR). The expected temperature decrease of diesel exhaust will adversely affect the CO and unburned hydrocarbons (UHC) conversion efficiency of the catalysts. Therefore, the development cost for the design and control of new DOCs is increasing.
Technical Paper

Stability Analysis of Automotive Supervisory Control: A Survey

2011-04-12
2011-01-0974
This paper focuses on stability of automotive supervisory control systems (ASCSs). It serves to introduce the concept of stability with respect to an entire ASCS. The realm of ASCSs is categorized and a brief description of pre-existing classical methods of stability analysis is presented. With the concept then having been fully introduced, an approach to evaluating stability of a key category of ASCS, the rule-based deterministic ASCS, is presented. This approach, cited from unrelated modern literature concerning stability of deterministic finite state machines, is novel in that its original target research area was not specifically automotive engineering.
Journal Article

Linear Quadratic Game Theory Approach to Optimal Preview Control of Vehicle Lateral Motion

2011-04-12
2011-01-0963
Vehicle stability is maintained by proper interactions between the driver and vehicle stability control system. While driver describes the desired target path by commanding steering angle and acceleration/deceleration rates, vehicle stability controller tends to stabilize higher dynamics of the vehicle by correcting longitudinal, lateral, and roll accelerations. In this paper, a finite-horizon optimal solution to vehicle stability control is introduced in the presence of driver's dynamical decision making structure. The proposed concept is inspired by Nash strategy for exactly known systems with more than two players, in which driver, commanding steering wheel angle, and vehicle stability controller, applying compensated yaw moment through differential braking strategy, are defined as the dynamic players of the 2-player differential linear quadratic game.
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