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Grip feeling is an important facet in vehicle dynamics evaluation from a driver satisfaction and enjoyment standpoint. To improve grip feeling, we analyzed the subjective comments from test driver's about grip feeling and an evaluated human sensitivity to lateral motion. As a result, we found that drivers evaluate transient grip feeling according to the magnitude of lateral jerk. Next, we analyzed what vehicle parameters affect lateral jerk by using theoretical equations. As a result, we found that cornering power is an important parameter, especially the cornering power of rear tires as they can be create larger lateral jerk than can front tires.

Improvement of vehicle dynamics in limit cornering have been studied. Simulations and tests have verified that vehicle stability and course trace performance in limit cornering have been improved by active brake control of each wheel. The controler manages vehicle yaw moment utilizing difference braking force between left and right wheels, and vehicle deceleration utilizing sum of braking forces of all wheels.

In-wheel motors (IWM) will be a key technology that contributes to the popularization of electric vehicles. Combining electric drive with IWM enables both good vehicle dynamics and a roomy interior. In addition, the responsiveness of IWM is also capable of raising dynamic control performance to an even higher level. IWM enable vertical body motion control as well as direct yaw control, electric skid control, and traction control. This means that IWM can replace most control actuators used in a vehicle chassis. The most important technology for IWM is to enable the motor to coexist with the brake and the suspension arms inside the wheel. The IWM drive unit described in this paper can be installed with a front double wishbone suspension, the most difficult configuration.

In vehicle control systems such as ABS (anti-lock braking system) or active suspension control, sensors for detecting longitudinal and/or lateral acceleration of vehicles (acceleration of up to ± 9.8 m/s2, with frequency range of DC to 20 Hz) is necessary. The principle of acceleration detection for this sensor is as follows. A permanent magnet levitates steadily in magnetic fluid by the action of the magnetic field generated by the magnet itself. The magnet moves by the application of acceleration on the mass of the magnet. This change of position of the magnet is detected by the Hall element, and thus acceleration is measured as an electrical signal. This sensor consists of only magnetic fluid, a permanent magnet, housing, a pair of Hall elements and an electronic circuit.

In order to develop the valve rocker arm material for the new type engine, we investigated various materials whose chemical compositions were selected using 30% chromium cast iron, which had shown good results in screening evaluation tests, as the basis. High chromium cast irons are well known for their abrasive wear resistance, but it has been very difficult to apply them for use as rocker arm material because their machinability is very poor, and because it is difficult for them to have a regular microstructure. In this paper, both the manufacturing method for the rocker arm which decreases the disadvantages that high chromium cast iron have and the rocker arm material best suited for this method are described.

In recent years, many various energy sources have been investigated as replacements for traditional automotive fossil fuels to help reduce CO2 emissions, respond to instabilities in the supply of fossil fuels, and reduce emissions of air pollutants in urban areas. Toyota Motor Corporation considers the plug-in hybrid vehicle (PHV), which can efficiently use electricity supplied from infrastructure, to be the most practical current solution to these issues. For this reason, Toyota began sales of the Prius Plug-in Hybrid in 2012 in the U.S., Europe and Japan. This is the first PHV to be mass-produced by Toyota Motor Corporation. Prior to this, in December 2009, Toyota sold 650 PHVs through lease programs for validation testing in the U.S., Europe and Japan. Additional 30 PHVs were introduced in China in March 2011 for the same objective.

The SEA model of wind noise requires the quantification of both the acoustic as well as the turbulent flow contributions to the exterior pressure. The acoustic pressure is difficult to measure because it is usually much lower in amplitude than the turbulent pressure. However, the coupling of the acoustic pressure to the surface vibration is usually much stronger than the turbulent pressure, especially in the acoustic coincidence frequency range. The coupling is determined by the spatial matching between the pressure and the vibration which can be described by the wavenumber spectra. This paper uses measured vibration modes of a vehicle window to determine the coupling to both acoustic and turbulent pressure fields and compares these to the results from an SEA model. The interior acoustic intensity radiating from the window during road tests is also used to validate the results.

Sensors which can detect minimal acceleration such as ± 9.8 m/sec2 in longitudinal and lateral direction of a vehicle, for DC to 20 Hz range, are required to control ABS (anti-lock braking system) or suspension system. To fulfill these requirements, we have developed a one-dimensional acceleration sensor, using magnetic fluid, to control the vehicle. In 1992, we submitted a paper on this sensor at the SAE International Congress and Exposition. Based on this one-dimensional acceleration sensor, we have developed an acceleration sensor which can detect two dimensional acceleration using a single inertia mass. This sensor is compact and can detect minimal acceleration with high accuracy. Spring and damping functions were obtained via the adoption of magnetic fluid, as in the case of the former one-dimensional acceleration sensor. This sensor can sustain mechanical shocks.

TOYOTA has designed a new family of automatic transaxles named the “Super ECT”. These are the next generation of automatic transaxles (AT), for FWD passenger cars. The aim of this development was compactness, lightness, and improvements in fuel economy and shift quality. There are several kinds of transaxles included in this group to match each of the FWD passenger cars and engines. The “U340E,” a four-speed automatic transaxle, has been developed as one member of this family. This is one of the most compact and light AT in its class, and has greatly contributed to the fuel economy of vehicles. This paper will give an overview of the “Super ECT” and the major features and performance of the U340E.

Toyota has developed a new system, which uses integrated control of powertrain by PowerTrain Management (PTM), in order to improve driving comfort and reliability. This system is currently in use on Lexus's new LS460. This system is composed of 4 parts: a generation part, a mediating part, a modification part and a distribution part. In each part, processes are based on drive power and torque. In the generation part, requests from a programmed model driver, Driving Support Computer and Vehicle Dynamics Integrated Management (VDIM) are generated and expressed by drive power. In the mediating part, most suitable vehicle drive power was selected among the requests. In the modification part, the selected request is modified using a programmed powertrain model, which considers internal combustion engine condition and powertrain response and transmission's tolerance. In the distribution part, optimized engine torque and gear ratio are processed.

The design requirement for more efficient vehicle moves a compact car toward front wheel drive arrangement, which requires an entire redesign of its power train. Toyota, with systematic approach from its planning stage, has developed a new automatic transmission series including one 3-speed and two 4-speed transmissions. An extensive examination on gear train arrangements enabled the 3-speed light, compact and highly reliable under the arrangement of Simpson gear train, and freewheel shifts with one-way clutches at every shifting. Two different 4th gear packages with freewheel shift are combined with the 3-speed unit to provide the versatility for the 4-speed units in various installations. Besides, these transmissions feature lock-up clutch converter, oil pump of a new tooth profile and two different control systems: hydraulic and electro-hydraulic.

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.

TOYOTA MOTOR CORPORATION had developed the world's first microprocessor controlled suspension system, Toyota Electronic Modulated Suspension (TEMS), which is now being offered on the Toyota Soarer from Feb. '83. This system consists of sensors, switches, electronic control unit (ECU), actuators and shock absorbers. TEMS uses a microprocessor to adjust the damping forces of the front and rear shock absorbers. As a result, suspension can be tuned in two stages (hard and soft cushioning) and driver can choose three control modes (AUTO, SPORT, NORMAL). In AUTO mode, the TEMS system has achieved attitude controls (i.e. squat control, roll control and nosedive control). The TEMS system achieved a 15 - 30% decrease of squat, a 20 - 30% decrease of roll angle, a 10 - 30% decrease of nose-dive and a 30 - 40% decrease of shift-squat.

The torque converter clutch slip control system adopted in the Toyota A541E automatic transaxle engages the torque converter clutch by applying a steady slip speed to prevent the torque fluctuation of the engine to be transmitted to the drivetrain while enhancing the transmission efficiency of the torque converter. The feedback controller of the slip speed adopts the H∞ (H-Infinity) control theory which offers a high level of robust stability, and is the first of its kind in a mass produced component. As a result, a highly accurate and reliable system has been realized, contributing to large-scale fuel economy.

To prevent global warming, further reductions in carbon dioxide are required. It is therefore important to promote the spread of electric vehicles powered by internal combustion engines and electric vehicles without internal combustion engines. As a result, emissions from hybrid electric vehicles equipped with internal combustion engines should be further reduced. Interest in catalytic reactions in an electric field with a higher catalytic activity compared to conventional catalysts has increased because this technology consumes less energy than other electrical heating devices. This study was therefore undertaken to apply a catalytic reaction in an electric field to an exhaust emission control. First, the original experimental equipment was built with a high voltage system used to conduct catalytic activity tests.

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.

The need for small personal mobility vehicles is growing as urbanization, the aging of society, traffic congestion, and parking become major issues, particularly in inner-city areas. The aging of society also means that more short trips within communities will be made. The i-REAL personal mobility vehicle is a next-generation single-passenger electric vehicle that enables the driver to move around town using a smaller amount of energy. This compact EV has three wheels: two front wheels driven by in-wheel motors and one rear wheel. According to the driver's needs, the i-REAL switches driving modes by changing its wheelbase. It can go slowly, allowing the driver to meet the eyes of passers-by when driving in parks, on sidewalks, or inside shopping malls. When on the road, it can lower its height and drive quickly like a bicycle or motorcycle. The body of the i-REAL leans automatically based on the speed and the turn angle to maintain the balance of the vehicle for any driver.

In order to reduce CO2, EV and Hybrid Vehicle (HV) are effective. Those type vehicles have different power train from conventional vehicle. Those new power trains drastically improve their efficiency from conventional vehicle with keeping same or superior power performance. On the other hand, those vehicles have the issue for thermal energy shortage during warming up process. The thermal energy is very large. The thermal energy seriously affect on the fuel economy for HV and the mileage for EV. In this paper, the power performance, the fuel economy and the effect of heat energy recovery from the exhaust gas are discussed for HV. For the power performance, the simulated acceleration time of 0-100km/h was 11.8sec and the measured vehicle time was 11.9sec. The error between simulation and actual measurement result was 1.2%. As for the fuel economy, the energy management using exhaust gas heat exchange system improved 10.3% of the fuel consumption during warming up.

We have developed the world's first 8-speed automatic transmission for transverse FWD/4WD vehicles. The aim of this new automatic transmission was to achieve world-class fuel economy while offering both smooth gear shift and sporty shift feeling suitable for luxury cars. This has been accomplished using wide spread gear ratio, outstanding low drag components and highly efficient hydraulic control system. In addition, we have achieved the compactness similar to current 6-speed automatic transmission by adopting new gear train and compact clutch layout. In this paper, the detail of this automatic transmission is introduced.

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.