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Journal Article

Development of Exhaust and Evaporative Emissions Systems for Toyota THS II Plug-in Hybrid Electric Vehicle

2010-04-12
2010-01-0831
Exhaust and evaporative emissions systems have been developed to match the characteristics and usage of the Toyota THS II plug-in hybrid electric vehicle (PHEV). Based on the commercially available Prius, the Toyota PHEV features an additional external charging function, which allows it to be driven as an electric vehicle (EV) in urban areas, and as an hybrid electric vehicle (HEV) in high-speed/high-load and long-distance driving situations. To reduce exhaust emissions, the conventional catalyst warm up control has been enhanced to achieve emissions performance that satisfies California's Super Ultra Low Emissions Vehicle (SULEV) standards in every state of battery charge. In addition, a heat insulating fuel vapor containment system (FVS) has been developed using a plastic fuel tank based on the assumption that such a system can reduce the diffusion of vapor inside the fuel tank and the release of fuel vapor in to the atmosphere to the maximum possible extent.
Journal Article

Development of HEV Engine Start-Shock Prediction Technique Combining Motor Generator System Control and Multi-Body Dynamics (MBD) Models

2013-05-13
2013-01-2007
Previous reports have already described the details of engine start-shock and the mechanism of vibration mechanism in a stationary vehicle. This vibration can be reduced by optimized engine and motor generator vibration-reduction controls. A prediction method using a full-vehicle MBD model has also been developed and applied in actual vehicle development. This paper describes the outline of a new method for the hybrid system of mechanical power split device with two motors that predicts engine start-shock when the vehicle is accelerating while the engine is stopped. It also describes the results of mechanism analysis and component contribution analysis. This method targets engine start-shock caused by driving torque demand during acceleration after vehicle take-off. The hybrid control system is modeled by MATLAB/Simulink. A power management and motor generator control program used in actual vehicles is installed into the main part of the control system model.
Journal Article

Decoupled 3D Moment Control for Vehicle Motion Using In-Wheel Motors

2013-04-08
2013-01-0679
Vehicles equipped with in-wheel motors are being studied and developed as a type of electric vehicle. Since these motors are attached to the suspension, a large vertical suspension reaction force is generated during driving. Based on this mechanism, this paper describes the development of a method for independently controlling roll and pitch as well as yaw using driving force distribution control at each wheel. It also details the theoretical calculation of a method for decoupling the dynamic motions. Finally, it describes the application of these 3D dynamic motion control methods to a test vehicle and the confirmation of the performance improvement.
Technical Paper

Overview and Future Plan of Automotive Electronic Systems

1986-10-20
861060
This paper provides an overview of automotive electronic systems put into products over the past decade, and describes automotive electronics which have been demonstrated in experimental cars. In addition, future electronic systems found to be promising for the practical use in coming years and the direction of development of electronics are also discussed, as an extention of the overview mentioned above.
Technical Paper

Map Navigation Software of the Electro-Multivision of the '91 Toyota Soarer

1991-10-01
912790
This paper describes the Electro-Multivision map navigation software mounted in the Toyota Soarer (1991). The following functions are required of on-board map navigation software: 1. Indication of the exact position of the vehicle to the driver 2. Determination of the optimum path to the destination and presentation of this route to the driver in the simplest way 3. Accommodation of a wide variety of destinations and settings for different users The following gives some examples of how these functions are achieved and outlines the associated technologies. 1. Path finding and associated display technology Path finding algorithm and technology for displaying the calculated on the map; construction of a data base on CD-ROM 2. Technology for determination of the current position utilizing map matching and the global positioning system(GPS) A method with improved reliability based on two current position outputs obtained using map matching and the GPS and the mutual compensation method 3.
Technical Paper

Development of Abradable Flame Spray Coating Technology

1991-02-01
910400
The authors, et al. have succeeded in the practical application of the abradable flame spray coating, used in aircraft engines for the prevention of air leakage and the improvement of efficiency, to automobile turbochargers for the first time in the world. Two layers consisting of a bond coated layer and an abradable layer used to be coated by separate spray nozzles under the conventional technique. In this paper, equations of relations between various flame spray coating conditions and the quality of coated film, which were derived from measured results, will be described. Flame spray coating conditions, that allow the double layer coating by the same spray nozzle, have been determined for each layer. Temperatures and speeds of the flame were measured by means of two-color type high-speed cameras, and equations of their relations with the flame spray coating conditions are derived from the measured result.
Journal Article

Analysis of Piston Friction - Effects of Cylinder Bore Temperature Distribution and Oil Temperature

2011-08-30
2011-01-1746
Hybrid vehicles (HVs) are becoming more widely used. Since HVs supplement engine drive with motor power, the lubricant oil temperature remains at a lower level than in a conventional gasoline vehicle. This study analyzed the effect of cylinder bore temperature and lubricant oil temperature on engine friction. The results showed that, although the lubricant oil temperature was not relevant, the bore temperature had significant effect on piston friction. It was found that raising the temperature of the middle section of the cylinder bore was the most effective way of reducing piston friction.
Journal Article

Research into Engine Friction Reduction under Cold Conditions - Effect of Reducing Oil Leakage on Bearing Friction

2014-04-01
2014-01-1662
Fuel efficiency improvement measures are focusing on both cold and hot conditions to help reduce CO2 emissions. Recent technological trends for improving fuel economy such as hybrid vehicles (HVs), engine start and stop systems, and variable valve systems feature expanded use of low-temperature engine operation regions. Under cold conditions (oil temperature: approximately 30°C), fuel consumption is roughly 20% greater than under hot conditions (80°C). The main cause of the increased friction under cold conditions is increased oil viscosity. This research used the motoring slipping method to measure the effect of an improved crankshaft bearing, which accounts for a high proportion of friction under cold conditions. First, the effect of clearance was investigated. Although increasing the clearance helped to decrease friction due to the oil wedge effect, greater oil leakage reduced the oil film temperature increase generated by the friction.
Technical Paper

HILS Application for Hybrid System Development

2007-08-05
2007-01-3469
The hybrid system has the typical advantage that it can realize various types of system control, because the system has two power units, engine and motor. On the other hand, however, constraints are increasing due to the complexity of the vehicle system. Compared to the conventional HILS construction and application, there are mainly two typical characteristics or themes for HV-HILS (i.e. HILS for hybrid vehicle control development). Firstly, HV-HILS requires full vehicle simulation environment, because the plural ECU control logic is intricately intertwined. Secondly, recent HILS system needs to run with more accurate or complicated plant models which are necessary to develop more accurate vehicle control logic.
Technical Paper

Quantitative Analysis of the Relation between Flame Structure and Turbulence in HCCI Combustion by Two-Dimensional Temperature Measurement

2008-04-14
2008-01-0061
The structure of HCCI (homogeneous charge compression ignition) combustion flames was quantitatively analyzed by measuring the two-dimensional gas temperature distribution using phosphor thermometry. It was found from the relation between a turbulent Reynolds number and Karlovitz number that, when compared with the flame propagation in an S.I. engine, HCCI combustion has a wider flame structure with respect to the turbulence scale. As a result of our experimentation for the influence of low temperature reaction (LTR) using two types of fuel, it was also confirmed that different types of fuel produce different histories of flame kernel structure.
Technical Paper

Development of New Hybrid System for Compact Class Vehicles

2009-04-20
2009-01-1332
Toyota has been evolving a hybrid system since introducing the first mass-production hybrid vehicle in 1997 in response to the increasing automotive-related issues of CO2 emissions, energy security, and urban air pollution. This paper describes a newly developed hybrid system design and its performance. This system was developed with the main purpose to improve fuel consumption, especially for better real world fuel consumption; and to enhance its compatibility with multiple vehicle adoption by downsizing and reducing the weight of its components. At the same time, the hybrid system achieved improved power performance while satisfying stringent emission regulations in the world.
Technical Paper

Development of open laboratory automation system

2000-06-12
2000-05-0170
We urgently need to develop the next generation of automotive technology to support energy conservation and the global environment. For this we need an advancement of the Laboratory Automation System (LAS). However, restructuring the hardware and software of the LAS requires enormous amounts of time and costs. To solve the problems of the LAS development, we formed a user-vendor working group, which then established the common rules of LAS and IMACS (Integrated Measurement And Control System). IMACS are software-centered rules, characterized by the stratification of LAS and the interface called software parts. So far, we have integrated IMACS into five engineering fields. A total of 11 testing machine vendors participated in the development. We manufactured about 350 software parts and made their specifications openly available. As the next step, we are collecting software parts by deleting redundant functions.
Technical Paper

Development of New Concept Iridium Plug

2001-01-05
2001-01-1201
In the field of automotive gasoline engines, new products aiming at greater fuel economy and cleaner exhaust gases are under development with the aim of preventing environmental destruction. Severe ignition environments such as lean combustion, stronger charge motion, and large quantities of EGR require ever greater combustion stability. In an effort to meet these requirements, an iridium plug has been developed that achieves high ignitability and long service life through reduction of its diameter, using a highly wear-resistant iridium alloy as the center electrode.(1)(2) Recently, direct injection engines have attracted attention. In stratified combustion, a feature of the direct injection engine, the introduction of rich air-fuel mixtures in the vicinity of the plug ignition region tends to cause carbon fouling. This necessitates plug carbon fouling resistance.
Technical Paper

Automatic Transmission Control System Developed for Toyota Mild Hybrid System (THS-M)

2002-03-04
2002-01-1253
Environmental improvement is moving forward, due in part to the reduction of fuel consumption of automatic transmission(AT) vehicles as a result of social requirements in recent years and many measures have been implemented. Adoption of idling stop is a typical example introduced to reduce energy consumption while the vehicle is stopped to improve the urban environment. However, there are problems such as responsiveness and smoothness for an AT vehicle when the engine is stopped with the shift selector in “D” range. To overcome these problems, a new start clutch control system has been developed using an electric oil pump installed in a simple hybrid vehicle called a mild hybrid. As a result, a smooth feeling starting performance is achieved by operating the system in combination with the engine and other systems.
Technical Paper

Development of Fuel-Cell Hybrid Vehicle

2002-03-04
2002-01-0096
Toyota Motor Corporation developed the Fuel Cell Hybrid Vehicle (FCHV). The FCHV-4 is an evolution of the conventional fuel cell vehicle that has made immense improvements in efficiency. Both a fuel cell and a secondary battery are used as sources of energy for the hybrid system. By using these energy sources proportionally, the system can be kept at or near its optimum state. The FCHV-4's system is designed to improve the efficiency and aims for high responsiveness when the vehicle is in a transitional state. In the same way as most electric vehicles, and as in the gasoline powered hybrid “Prius”, the energy the traction motor creates during breaking can be used to regenerate the secondary. The fuel cell and traction motor inverter are connected directly, with the secondary battery connected through the DC/DC converter to the fuel cell in parallel.
Technical Paper

Use of FEA Concept Models to Develop Light-Truck Cab Architectures with Reduced Weight and Enhanced NVH Characteristics

2002-03-04
2002-01-0369
Many recent developments in automotive technology have resulted from the need to improve fuel economy without sacrificing passenger comfort or safety. This paper documents an effort to reduce the weight of dual-use military/civilian vehicles through the use of innovative design architectures. Specifically, a number of crossmember architecture concepts were developed for the cab floorpan of a light-duty truck. The floorpan is a key structural component of any vehicle, providing a significant contribution to noise, vibration, and harshness parameters such as stiffness and normal modes. Finite element concept models of the baseline cab and concept cabs are used to show that changes in the crossmember architecture can significantly reduce cab weight without compromising structural performance.
Technical Paper

Development of an Electrical 4WD System for Hybrid Vehicles

2002-03-04
2002-01-1043
In June 2001, Toyota introduced its second hybrid vehicle to the Japanese market. It adopted a newly developed hybrid system that includes the world's first electrical four-wheel drive (4WD) system. In the development of this electrical 4WD system, it was necessary to determine the required rear motor torque to allow practical 4WD performance while maintaining excellent fuel economy. Initially, the factors affecting 4WD performance were quantitatively analyzed and then the rear wheel drive unit torque was optimized. This results in a new hybrid vehicle with practical 4WD performance and high efficiency.
Technical Paper

A New Battery System for the Estima Hybrid Minivan

2002-03-04
2002-01-1090
Development of a new battery system for Toyota Estima Hybrid, the world's first minivan hybrid vehicle, has been completed. The battery pack that consists of 30 nickel metal hydride battery modules is compactly arranged under the 3rd seat in the cabin along with components such as the battery cooling blower and the ducts. This arrangement was designed in consideration of user's vehicle use, passengers' comfort and efficient battery-cooling performance.
Technical Paper

Toyota Five-Speed Automatic Transmission with Application of Modern Control Theory

1992-02-01
920610
A compact and high-performance five-speed automatic transmission(A350E) has been developed for passenger cars. The development of this transmission has been aimed at improvement in acceleration performance in the low and medium speed range and at smooth acceleration. A five-speed automatic transmission with a simple gear train has been completed by means of the industry's first modern control theory aided shifting technique.
Technical Paper

The Humidity Control System Applied to Reduce Ventilation Heat Loss of HVAC Systems

2011-04-12
2011-01-0134
Vehicles have been more required to save energy against the background of the tendency of ecology. As the result of improving efficiency of internal combustion engines and adoption of electric power train, heat loss from engine coolant, which is used to heat the cabin, decreases and consequently additional energy may be consumed to maintain thermal comfort in the passenger compartment in winter. This paper is concerned with the humidity control system that realizes reduction of ventilation heat loss by controlling recirculation rate of the HVAC system by using highly accurate humidity sensor to evaluate risk of fogging on the windshield. As the results of the control, fuel consumption of hybrid vehicles decreases and maximum range of electric vehicles increases.
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