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In order to meet increasing demands for safety and comfort in a vehicle compartment, automatic adjustment of seat, mirrors, steering wheel has been developed. The multiplex wiring system was constructed for the automatic adjustment of the cockpit elements to drivers preferred positions or to physique-matched settings based on ergonomic data. This paper describes the construction of the multiplex system and functions of automatic adjustment of the cockpit elements for comfortable driving position and better visibility.

In this paper, we suggest a novel algorithm to distinguish semi-steady states from various steering patterns and to estimate the stability factor. The algorithm also estimates each stability factor in left and right turns because there could be a case where they differ based on uneven tire wear and so on. The stability factor, which is the turning characteristic of a vehicle, has been treated as constant for most vehicle control systems. However, in fact, it may change in some situations, for example when a vehicle is overloaded. So there is a chance that a driver may be aware of an unusual sensation when vehicle control is designed based on a constant stability factor. We have succeeded in developing an algorithm to estimate the stability factor accurately enough to be able to compensate for it and have confirmed the effectiveness of the algorithm by simulation and vehicle testing as well.

Following the previous reports, ventilation characteristics in automobile was investigated by using a half-scale car model which was created by the Society of Automotive Engineers of Japan (JSAE). In the present study, the ventilation mode of the cabin was foot mode which was the ventilation method for using in winter season. Supplied air was blown from the supply openings under the dashboard to the rear of the model via the driver's foot region in this mode. The experiment was performed in order to obtain accurate data about the airflow properties equipped with particle image velocimetry (PIV). Our experimental data is to be shared as a standard model to assess the environment within automobiles. The data is also for use in computational fluid dynamics (CFD) benchmark tests in the development of automobile air conditioning, which enables high accuracy prediction of the interior environment of automobiles.

This paper presents a new motor current control strategy for Electric Power Steering (EPS) to reduce current fluctuation. Such current fluctuation may cause undesirable steering torque ripple and acoustic noise, if an inexpensive microprocessor is used. Using a DC-motor, current fluctuation associated with change in the battery voltage, etc., may occur. We have developed a new current control strategy which effectively alleviates current fluctuations of the motor without using higher performance microprocessors. The new controller is based on the estimation of disturbance voltage and compensation for this disturbance voltage. We have bench-tested the performance of this control strategy and confirmed that current fluctuation is reduced below that using conventional PI controller. The PI gain for the proposed controller is the same as that for the conventional controller.

New numerical simulation system and experimental evaluation system has been developed to predict and evaluate occupant's thermal sensation in a passenger compartment in which environment is not steady and not uniform. Transitional effective temperature, which is new index of thermal sensation, is proposed and verified to correspond with subjects' thermal sensation votes. The simulation system has two advantage beside the prediction of thermal sensation; automatic generation of a computational model and coupling analysis of temperature including an analysis of temperature distribution inside a cabin, refrigerating cycle, solar radiation, and so on. It was verified that this system well predicts occupant's thermal sensation in a short time.

The gasoline direct injection engine starts significantly faster than a conventional engine. Fuel can be injected into the cylinder during the compression stroke at the same time of cranking start. When the spark plug ignites the mixture at the end of compression stroke, the engine has its first combustion, that is, the first combustion occurs within 0.2 sec after the start of cranking. This unique characteristic of quick startability has realized a idle stop system, which enables drivers to operate the vehicle in a natural manner.

This paper proposes a new Electric Power Steering (EPS) control strategy that improves steering maneuverability especially on slippery roads. In a conventional steering system (including mechanical and hydraulic ones), poor steering wheel returnability associated with reduced alignment torque from the road may lead to awkward handling on slippery roads. In experiments with a test driver, we found that this phenomenon occurs because of the delay in the driver turning the steering wheel to avoid spinning the vehicle. This delay comes from a lower steering wheel returnability than driver expected. Increasing the steering wheel returnability will be effective in avoiding this problem. This can be realized by using the steering angle feedback or the estimated alignment torque feedback. However, the simple feedback of such values will provide drivers with poor road information when the road is slippery.

A trap system has been developed that collects particulate using two small filters and regenerates alternately by electric heaters. This system contains a new idea in detection of the amount of particulate accumulation in the filters. The system counts the amount using a particulate accumulation rate map which is a function of the engine load and speed. In vehicle test with this trap system, the particulate collection efficiency and the regeneration efficiency were proved to be high enough for practical use. The test results also showed that the shutdown performance of the route switch valve greatly influenced the regeneration efficiency.

Recently, development of vehicle control system targeting Full Driving Automation (autonomous driving level 5) has advanced. Some applications of autonomous driving systems like the Lane Keeping Assist system (LKA) and Auto Lane Change system (ALC) (autonomous driving level 1-3) have been put on the market. However, the conventional system using information from front camera, it is difficult to operate in some situations. For example the road that no line, large curvature and number of lane increases or decreases. We propose an autonomous driving system using high accuracy vehicle position estimation technology and a high definition map. An LKA system calculates the target steering wheel angle based on both vehicle position information from the Global Navigation Satellite System (GNSS) and the target lane of high the definition map, according to the method of front gaze driver model. Then, the system controls steering the wheel angle by Electric Power Steering (EPS).

In previous studies(1)(2), the acceleration performance of vehicles equipped with torque converter has been analysed with the assumption that the converter characteristic was under continued steady-state. However, in case of sharp acceleration of the fluid flow in the converter from inactive flow condition, which would occur at wide-open throttle starting, it is not possible to accurately analyse the vehicle performance at immediately after starting if the converter characteristic is assumed to remain under steady-state condition. In this paper, the transient phenomenon in the converter is verified by applying the theory of angular momentum and the concept of energy balance through the converter elements providing with a dynamic-model for the driveline. The present study has clarified the effect of the transient converter characteristic, at sharp starting, on the acceleration performance.

Stirling engine and Stirling engine driven heat pump system (SEHP) has been developing in four years project assisted by Ministry of International Trade and Industry (MITI). In this development, 6 kW output displacer type engine and 5HP class SEHP installing with that engine were designed and manufactured Several component technologies such as combustor, heat exchanger, crank mechanism, mechanical seal etc. were also investigated in order to ensure the engine reliability. For the performance of SEHP, a capacity of 12,500 kcal/hr for cooling and 15,000 kcal/hr for heating, respectively, was achieved. Approximately 20,000 hours of accumulative operation time in total of 9 units and 7,000 hours of the one unit longest time were recorded in the field test, which demonstrated durability of SEHP.

This paper concerns driver's burden for visual information processing in which his central vision is coupled with his peripheral one. A visual driving simulator was applied to the first step of the study, where driver's responses to both central and peripheral tasks were simultaneously investigated. The series of test indicate that the driver's responsiveness to the central and peripheral tasks could define the whole burden for visual information processing. Therefore, it appears that the responsiveness to the peripheral vision could be more or less compromised to support the central one.

This paper describes a method of predicting cooling performance in order to obtain the optimum design of the cooling system and front-end shape in the early stage of car development. This method consists of four calculation parts: thermal load on the cooling system, air flow through the engine compartment, heat dissipation by the heat exchangers and temperature distribution within the cooling system. It outputs the coolant, engine oil, automatic transmission fluid (A.T.F.) and charge air temperatures in exchange for the input of several car, power plant, drive train, exterior shape and cooling system specifications. For the calculations, in addition to theoretical formulas, several experimental formulas are introduced. This method verification is shown by presenting a few test cases for the respective calculation parts and the final solution.

This paper describes an experimental analysis of frictional heat generated between the pads and rotors of disc brakes, to determine the paths and amounts of heat flow. The brakes were applied repeatedly at a constant initial speed, deceleration and interval until brake temperature became saturated. Under these conditions we measured an unsteady temperature distribution state during a single application of the brakes, and also a saturated (quasi-stationary) temperature distribution during repeated braking. Heat flow was studied in six paths: heat conduction to the pad; heat convection to the air from the friction areas of the inner and outer disc, from the ventilating parts and from the tube section of the rotor; and heat conduction to the rotor flange section.

We have developed a driving simulator for Electric Power Steering (EPS), which can be used to evaluate steering maneuverability on low μ roads. The simulator calculates an 11 DOF (degrees of freedom) vehicle motion based on the steering wheel angle, the accelerator pedal position and the brake pedal position which are operated by the driver. A reaction torque corresponding to the alignment torque is applied to the steering shaft using motors. A 3D CG reproducing the view from the cockpit is displayed on a forward screen. The simulator also includes column type EPS, which generates the assist torque. Consequently, the driver feels the steering torque with good reality. The tire model we used is non-linear and it enables us to simulate the vehicle dynamics also on slippery roads. We compared driver behavior in vehicle and simulator tests and found the simulator could evaluate the relationship between steering maneuverability and EPS control strategy even when the road was slippery.

One of the leading causes of traffic accidents is the reduction of driver's arousal level. Only a driver with an appropriate arousal level can drive an automobile properly. The purpose of this research is to find the possibility of quantifying the reduction of this arousal level. Two methods are used to quantify the reduction in arousal level: one is related to the driver's behavior, and the other is related to his physiological status. The characteristics of controlling the steering wheel are used as indicators of the driver's behavior, which represents the status of information processing in the brain. The variation of heart rate is used as an indicator of physiological status, which could directly represent arousal level related to drowsiness. Eight male and two female drivers participate both in on-the-road tests for the characteristics of controlling the steering wheel and in a test with a driving simulator for the heart rate variation.

A Finite Element Method (FEM) simulation was conducted to predict energy-absorbing characteristics in an impact of a head form against plastic plates. Static and dynamic material tests were conducted in order to determine material properties of the plastics. The properties were applied in an explicit FEM code. The FEM results were validated through the impact tests by the head form against the same plastic plates. It was proved that the FEM could simulate the test result well, when the precise material properties were introduced in the simulation. The method can be expected to be available to predict energy-absorbing characteristics during the impact by the head form against automobile plastic components such as shell portions of instrument panels.

An investigation of anti-corrosion steel sheets (non-galvanized) which contain copper for automobile body parts has been conducted. Copper additives accelerate the formation of amorphous substrates. These substrates decrease the rate of corrosion. In order to retain the steel's formability and weldability, the contents of the alloying elements have been optimized. As a result, this newly developed steel sheet can be used for many different applications such as door sashes and door panels of mass produced cars. This paper describes the key properties of the newly developed steel sheet and additionally the mechanism of corrosion prevention, weldability, formability, and so on.

We have developed an effective secondary air-injection system that reduces harmful substances such as HC and CO. The secondary air in this system is heated to 300°C and injected into the exhaust pipe. Though the temperature of the secondary air is relatively low, it can activate a three way catalyst more rapidly than conventional secondary air injection systems. Thus, in our system (a “Heated-Air-Injection System”) is expected to be very effective in reducing harmful substances in the cold transient phase of the US Federal Test Procedure. For designing the system and analyzing its performance, we developed a simulation model including the design parameters of the system, such as flow rate of heated air, heater power, and so on. Besides these design parameters, the model takes into account of heat transfer from exhaust gas to exhaust pipe, gas-conversion reactions in a three way catalyst, and heat transfer efficiency of the electric heater.

Since it is more difficult for truck door panels to realize curvature than passenger car door panels, internal stiffeners are mounted between the outer panel and inner panel through the use of an adhesive for ensuring stiffness. For this reason, a problem occurs as to the proper placement of the stiffeners so as to effectively improve stiffness. By FEM prediction and experimentation, the following have been clarified: (1) Arrangement of stiffeners for effectively improving stiffness (2) Stiffness share of stiffeners and outer panel against stiffness