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Engine starting vibration of hybrid vehicle with Toyota hybrid system has variations even in the same vehicle, and a large vibration that occurs rarely may cause stress to the passengers. The contribution analysis based on the vibration theory and statistical analysis has been done, but the primary factor of the rare large vibration has not been clarified because the number of factors is enormous. From this background, we apply machine learning that can reproduce multivariate and complicated relationships to analysis of variation factors of engine starting vibration. Variations in magnitude of the exciting force such as motor torque for starting the engine and in-cylinder pressure of the engine and timing of these forces are considered as factors of the variations. In addition, there are also nonlinear factors such as backlash of gears as a factor of variations.

Toyota Motor Corporation has been actively pursuing the development of fuel cell vehicles (FCVs) to respond to global environmental concerns and demands for clean energy. Toyota developed the first fuel cell (FC) bus to receive vehicle type certification in Japan. Subsequently, a new FC bus has been developed, which adopts two FC systems and four high-voltage batteries to achieve the required high power performance and durability. For enhanced durability, the FC system is controlled to maximize usage of the high-voltage batteries and to reduce the number of electric potential changes of the fuel cell. To accomplish this, the voltage of the FC stack must be kept high and FC power must be kept low. The high-voltage batteries were used to actively minimize FC power during acceleration.

Roadway departure mitigation systems for helping to avoid and/or mitigate roadway departure collisions have been introduced by several vehicle manufactures in recent years. To support the development and performance evaluation of the roadway departure mitigation systems, a set of commonly seen roadside surrogate objects need to be developed. These objects include grass, curbs, metal guardrail, concrete divider, and traffic barrel/cones. This paper describes how to determine the representative color of these roadside surrogates. 24,762 locations with Google street view images were selected for the color determination of roadside objects. To mitigate the effect of the brightness to the color determination, the images not in good weather, not in bright daylight and under shade were manually eliminated. Then, the RGB values of the roadside objects in the remaining images were extracted.

Engine oil formulation is known to affect low speed pre-ignition (LSPI), which creates technical restrictions on downsized turbocharged engines. Calcium, which is used to ensure detergency and anti-rust performance, is reported to increase LSPI events. Therefore, new formulation technologies are needed to satisfy both LSPI prevention performance and other conventional performance areas. The authors focused on two approaches: enhancement of LSPI prevention performance by adding a booster component and substitution of calcium for a less reactive component to balance performance areas including LSPI prevention. We have verified the effectiveness of these approaches by increasing the dosage of molybdenum used as a friction modifier as well as replacing calcium detergent with a magnesium detergent. These formulation strategies can be applicable for future ILSAC GF-6 engine oil, where a specification for LSPI prevention performance is expected to be implemented.

This research developed a new measurement technology for thermal analysis of the heat radiation from a hybrid transaxle case surface to the air and improved the heat radiation performance. This heat flux measurement technology provides the method to measure heat flux without wiring of sensors. The method does not have effects of wiring on the temperature field and the flow field unlike the conventional methods. Therefore, multipoint measurement of heat flux on the case surface was enabled, and the distribution of heat flux was quantified. To measure heat flux, thermal resistances made of plastic plates were attached to the case surface and the infrared thermography was used for the temperature measurement. The preliminary examination was performed to confirm the accuracy of the thermal evaluation through heat flux measurement. The oil in the transaxle was heated and the amount of heat radiation from the case surface was measured.

Countries and regions around the world are tightening emissions regulations in reaction to the increasing awareness of environmental conservation. At the same time, growing concerns about the depletion of raw materials as vehicle ownership continues to increase is prompting automakers to look for ways of decreasing the use of platinum-group metals (PGMs) in the exhaust systems. This research has developed a new catalyst with strong robustness against fluctuations in the exhaust gas and excellent nitrogen oxide (NOx) conversion performance. This catalyst incorporates rhodium (Rh) clusters with a particle size of several nanometers, and stabilized CeO2-ZrO2 solid-solution (CZ) with a pyrochlore crystal structure as a high-volume oxygen storage capacity (OSC) material with a slow O2 storage rate.

The new Toyota FCV “Mirai” has reduced the weight, size, and cost of the high-pressure hydrogen storage system while improving fueling performance. The four 70 MPa tanks used on the 2008 Toyota FCHV-adv were reduced to two new larger diameter tanks. The laminated structure of the tanks was optimized to reduce weight, and a high-strength low-cost carbon fiber material was newly developed and adopted. The size of the high-pressure valve was reduced by improving its structure and a high-pressure sensor from a conventional vehicle was modified for use in a high-pressure hydrogen atmosphere. These innovations helped to improve the weight of the whole storage system by approximately 15% in comparison with Toyota FCHV-adv, while reducing the number of component parts by half and substantially reducing cost. The time required to fuel the FCV was greatly reduced by chilling the filling gas temperature at the hydrogen filling station to −40°C (as per SAE J2601).

At the engine restart, when the temperature of the catalytic converter is low, additional fuel consumption would be required to warm up the catalyst for controlling exhaust emission.The aim of this study is to find a thermally optimal way to reduce fuel consumption for the catalyst warm up at the engine restart, by improving the thermal retention of the catalytic converter in the cool down process after the previous trip. To make analysis of the thermal flow around the catalytic converter, a 2-D thermal flow model was constructed using the thermal network method. This model simulates the following processes: 1) heat conduction between the substrate and the stainless steel case, 2) heat convection between the stainless steel case and the ambient air, 3) heat convection between the substrate and the gas inside the substrate, 4) heat generation due to chemical reactions.

The driving simulator (DS) developed by Toyota Motor Corporation simulates acceleration using translational (XY direction) and tilting motions. However, the driver of the DS may perceive a feeling of rotation generated by the tilting motion, which is not generated in an actual vehicle. If the driver perceives rotation, a vestibulo-ocular reflex (VOR) is generated that results in an unnecessary correction in the driver's gaze. This generates a conflict between the vestibular and visual sensations of the driver and causes motion sickness. Although such motion sickness can be alleviated by reducing the tilting motion of the DS, this has the effect of increasing the amount of XY motion, which has a limited range. Therefore, it is desirable to limit the reduction in the tilting motion of the DS to the specific timing and amount required to alleviate motion sickness. However, the timing and extent of the VOR has yet to be accurately identified.

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.

After the Great East Japan Earthquake on March 11, 2011, Toyota Motor Corporation received considerable public response regarding the role of vehicles in emergencies from a large number of customers. These included comments about the usefulness of the electricity supply system in the Estima Hybrid during the long power outages caused by the earthquake. In response, Toyota decided to install this system in its other hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). This system is capable of supplying power up to 1,500 watts, which means that it can be used to operate virtually every household electrical device. Since the engine starts automatically when the main battery capacity is depleted, a single vehicle can supply the daily power needs of a normal house in Japan for about four days, providing that the battery is fully charged and the fuel tank is full.

The development of the Lexus LFA focused on the pursuit of a passionate driving experience suitable for a super sports car. The shift speed control system in the LFA is an automated manual transmission (AMT) that uses an electrohydraulic actuator. The excellent shifting performance of the AMT was achieved by developing control technology that performs smooth, quick, and highly responsive shifting in accordance with the driving conditions. This was the result of repeated evaluations in both normal driving and on circuits featuring many acceleration, deceleration, and high-speed driving sectors. This paper describes the AMT shift speed control system and technology.

This paper describes an outline of the Toyota FCHV-adv, a fuel cell vehicle with a practical cruising range of more than 500 km. The cold startability of the FCHV-adv was improved by modifying the FC stack and control system. As a result, the FCHV-adv is capable of starting at a temperature of -30°C. In the future, Toyota intends to improve durability and reduce costs and is continuing to cooperate with governments and energy businesses to establish infrastructure and make the necessary modifications to laws and regulations.

The impact of fatty acid methyl ester (FAME) blended diesel fuel on engine/vehicle systems was comprehensively investigated by vehicle, laboratory and engine tests. In this study, 20% FAME blended fuel (B20) was mainly used and soy bean oil methyl ester (SME) was primarily selected as the FAME. Vehicle testing with long-term fuel storage in vehicle fuel tanks was conducted, considering the most severe conditions in market use. Laboratory and engine tests were also conducted to better understand the vehicle test results. In the vehicle test, engine startability, idle roughness and fuel injection control were evaluated using nine vehicles with plastic or metal fuel tanks. All vehicles showed no problems up to 7 months. While five vehicles with plastic fuel tank did not show any problems throughout the test period up to 18 months, four vehicles with metal fuel tanks experienced malfunctions in engine start or fuel injection control following 8, 13, 13 and 18 months respectively.

This paper describes the development of a High Speed Calculation Diesel Combustion Model that predicts combustion-related behaviors of diesel engines from passenger cars. Its output is dependent on the engine's operating parameters and on input from on-board pressure and temperature sensors. The model was found to be capable of predicting the engine's in-cylinder pressure, rate of heat release, and NOx emissions with a high degree of accuracy under a wide range of operating conditions at a reasonable computational cost. The construction of this model represents an important preliminary step towards the development of an integrated Model Based Control system for controlling combustion in diesel engines used in passenger cars.

Plug-in hybrid vehicles (PHVs) and/or electric vehicles (EVs) as sustainable mobility rapidly penetrate into a new market. Cruising ranges of PHVs and EVs strongly depend on the energy density of batteries. In this paper, we briefly introduce our achievements of metal air batteries as one of the innovative batteries with high energy density.

It may be possible to simplify the structure and control systems of a lithium-ion battery by replacing the conventional liquid electrolyte with a solid electrolyte, resulting in higher energy density. However, power performance is a development issue of batteries using a solid electrolyte. To increase battery power performance, in addition to lithium ionic conductivity within the bulk of the electrolyte, it is also necessary to boost the lithium ionic conductivity at the interface between the electrode active material and the electrolyte, and to boost electron and lithium ionic conductivity within the cathode and anode active material. This research studied the mechanism of resistance reduction by electrode surface modification. Subsequently, this research attempted to improve electron conductivity by simultaneously introducing oxygen vacancies and carrying out nitrogen substitution in the crystalline structure of the Li4Ti5O12 anode active material.

The outline of the TOYOTA FCHV-adv is described in this paper. The TOYOTA FCHVadv achieved an approximately 25 percent improvement in vehicle fuel efficiency and about 1.9 times the amount of usable hydrogen in comparison with the previous model. These improvements have enabled almost 2.5 times longer practical cruising range, more than 500 km. The freeze start capabilities of the FCHV-adv were improved by modifying the FC stack and control system. As a result, the FCHV-adv has been capable of starting at a temperature of -30°C. In the future, TOYOTA intends to improve durability and reduce costs.

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 a year.

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.