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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.

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.

A new experimental method, that enables to estimate the body and driveline sensitivity to unit transmitting error of a hypoid gear for automotive rear axle gear noise, has been developed. Measurements were made by exciting the tooth of the drive-pinion gear and that of the ring gear separately using the special devices designed with regard to simulation of acceleration and deceleration. The characteristic of this method is to estimate the forces at the contact point of the gears. Estimation of these forces is carried out under the condition that the higher stiffness is provided by the tooth of the drive-pinion gear and that of the ring gear, compared with the stiffness of the driveshafts and that of the propeller shaft etc., and relative angular displacement of the torsional vibration between the teeth of the drive-pinion gear and those of the ring gear is constant.

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.

Electronic Control Units (ECUs) for automobiles are usually composed of a main single-chip microcomputer and peripheral circuits with some standard and/or custom ICs. The peripheral circuits vary with the kinds of control or models of automobiles. When the peripheral circuits are replaced with a single-chip microcomputer, the ECU becomes compact and low in cost. This is because the ECU is constructed with only two LSIs and can be used for various kinds of control and various models of automobiles only by changing the program of the microcomputer. The microcomputer, however, requires many I/O functions and high reliability. We have developed a new 4-bit microcomputer suitable for these requirements. The new microcomputer has two remarkable features. One is powerful I/O functions such as high speed I/O, serial I/O, parallel I/O, analog I/O, and default output that is generated in place of the calculated output by the main CPU when it fails.

A new ABS and Traction control system (TRAC system) has been developed and put into mass production in a new model LEXUS LS400. The TRAC system controls Sub-Throttle Valve and brake hydraulic pressure independently for left and right wheels. To realize the ABS and TRAC system,it is necessary for the Electronic Control Unit (ECU) to process complex algorithm and high speed calculation. The ABS and TRAC ECU for LEXUS LS400 is constructed by 3 TOYOTA custom 8-bit single chip microcomputers. Each CPU performs wheel speed calculation,ABS control and TRAC control,sharing the common data through high speed serial communication. This paper describes the function of each CPU,the method of CPU communication and fail safe function in the ECU.

The transfer efficiency for painting processes utilizing water-borne materials is low, and the residual paint is disposed of as waste. In this study, we focused on a recycling system to collect and dissolve the paint over-spray in the booth water, and to concentrate and regenerate it by means of an ultra filter (UF). Paint adaptable to the recycling system has been developed by providing compatibility between the high hydrophilicity of liquid paint and the high hydrophobicity of the paint film, in order to ensure the recyclability and the high anti-corrosion performance required of paint on automobile underbody parts. This recycling technology is used in an actual propeller shaft painting process and provides large waste reduction and a decrease in painting cost.

Toyota has developed a new continuously variable transmission (CVT) named “Super CVT”. The Super CVT has a wide ratio coverage and adopts a newly developed integrated control system with a direct injection gasoline engine (D-4) equipped with electronically controlled throttle. The combined package has achieved good fuel economy and a high overall level of performance. This paper shows the major features and performance of the Super CVT.

Authors have developed an apparatus which measures the piston temperature using electromagnetic induction. The characteristics of this apparatus are as follows; 1 Applicable to 6 points per cylinder and all cylinders 2 Capable of measuring while the engine is running from start to 6000r/min full-load operation 3 Wide measuring range; from -30 to 400 °C 4 High accuracy; ±2.5 °C 5 Quick and easy setup 6 High durability This technology contributes to realizing the best balance of piston reliability and matching of combustion conditions. In this report, authors analyzed its influences upon piston temperature when the ignition timing,the oil/water temperature or the oil flow from piston jet were changed, respectively.

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.

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.

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.

For the first time ever, a new hybrid system using a 42-V power supply system has been developed for better fuel economy, lower emissions and urban environment. This paper introduces the system configuration, features and gives actual vehicle evaluation results. This system has a motor generator (hereinafter abbreviated as M/G) connected to the engine crankshaft via a belt, in place of the alternator on a conventional vehicle. The electronic control of the M/G has five functions, 1 restarting the stopped engine, 2 driving the vehicle when starting, 3 driving auxiliaries when the engine is stopped, 4 power generation during ordinary traveling and 5 regenerative braking on deceleration braking. By restarting the engine via a belt with motor driving control, a smooth starting without discomfort is achieved. Furthermore, using this motor to drive auxiliaries during idle increases the number of idle stop opportunities.

On board multiplexing communication system is regarded as a necessary technology for the future of electronic system in automobiles. Many companies are developing multiplexing systems and the ISO and SAE are active in establishing standards for communication protocols. The proposed communication protocol specifications have different specifications. Consequently, no compatible evaluation standards existed, and it was difficult to compare one protocol to another. Therefore, to assist the standardization activities of the IS0 and SAE, we have developed an evaluation method for distributed multiplexed communication systems and evaluated each of the proposed protocols using this method. These evaluations were performed from the point of view of the future users of these systems. In this paper we present the results of the experiments on distributed multiplexed communication systems each of which consists of communication IC and the proposed physical layer.

A new technologies for manufacturing of engine valve seats have been developed. This process, different from the conventional method that valve seats made of sintered alloy were press-fit into the cylinder head, is directly formed valve seats onto cylinder head by using the laser cladding technique. In order to develope the cylinder head with laser cladding valve seats, the laser cladding technology by which copper based alloy is deposited onto aluminum alloy with little dilution and stable bead has been established. And the unique cladding alloy, which is two phases in the liquid stage and in which iron or molybdenum rich hard particles are dispersed in the solid state, has been developed. Based on this technique, the practical process has been successfully completed.

In the present social environment, automobile demands further reduction of fuel consumption and light weight. Now that the reduction of vehicle weight is being pursued, even a slight looseness in each element of an automobile may become a source of vibration and noise due to the lowered rigidity of such an automobile. The quietness of vehicles is urged, spline backlash in the spline mechanism exhibits a problem in some cases. A propeller shaft, a part of the automobile driving system, also has a sliding spline mechanism as shown in Fig. 1. Such a propeller shaft is required to have functions of transmitting high torque driving forces, and absorbing the variation of the vehicle driveline overall length at the same time. Vibration and noise are apt to occur if when torque is applied, there is a significant balance fluctuation or great sliding resistance due to spline backlash.

A smart analog integrated circuit (IC) is developed for use in an electronic control unit for an automotive variable power-steering system. This IC accepts a vehicle speed signal as its input, performs signal processings such as frequency to voltage conversion and function generation, and then as its output generates a pulse width modulated (PWM) signal whose duty corresponds precisely to a given piecewise linear function of the vehicle speed. The PWM output is used as a driving signal to a power MOSFET for the actuation and control of a linearly variable solenoid valve to vary the force needed for steering effort in a prescribed relation to the vehicle speed. The IC is fabricated by monolithic bipolar integrated circuit technology and has about 750 device elements in a chip size of 5.7 by 3.1 mm2. It is enveloped in a shrinked dual in-line package with 24 pins.

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.

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.

In this paper, the authors have developed a new measuring method of the liquid fuel film thickness on walls, such as intake ports, the combustion chamber and cylinder liner of a Port Fuel Injection (PFI) engine, and clarified the fuel film behavior under various running conditions when Fiber-based Laser-Induced Fluorescence (Fiber-based LIF) was applied to the newly developed method. The thickness of the fuel film is measured by detecting the intensity of fluorescence from the film that is irradiated by a He-Cd laser. A single optical fiber is used to simultaneously transmit the laser beam and the fluorescence from the film. In addition, the S/N ratio of the fluorescence is improved by using a He-Cd laser of which the wavelength (λ=442nm) is able to efficiently irradiate test fuel doped 2-3-butandione. Using this method, the fuel film thickness on the wall of the PFI engine was analyzed in two case studies.