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This paper deals with a blind spot assistance system that assists the driver by generating yaw-moment when a driver's lane change maneuver is detected and when there is an object present in the blind spot area of the adjacent lane. The system combines lane information and driver's maneuver information for estimating the driver's lane change. If the millimeter wave sensor detects an object in the rear blind spot area in the event of a lane change, direct yaw-moment in the opposite direction of the lane change maneuver is generated. The unique method of detecting driver's lane change, control method of assisting the driver to recover back in lane, and the system design to maintain driver compatibility is mentioned, together with the effectiveness of the system.

A method for detecting drivers' intentions is essential to facilitate operating mode transitions between driver and driver assistance systems. We propose a driver behavior recognition method using Hidden Markov Models (HMMs) to characterize and detect driving maneuvers and place it in the framework of a cognitive model of human behavior. HMM-based steering behavior models for emergency and normal lane changes as well as for lane keeping were developed using a moving base driving simulator. Analysis of these models after training and recognition tests showed that driver behavior modeling and recognition of different types of lane changes is possible using HMMs.

As a new generation sports car engine to lead the field in the 1990s, a 3.0 liter, 60°V, type 6 cylinder, 4 cam, 24 valve engine (VG30DETT) has been developed to achieve the utmost in high performance levels and reliability. it has been mounted on the new model 300ZX and announced in the North America and Japanese markets. The VG30DETT engine is based on the previous VG30DE engine (the engine mounted on the former model 300ZX designed for the market in Japan). The main components, the major driving and the lubrication systems including such parts as the crank shaft,con-rod, cylinder block, piston, exhaust manifold, and oil pan of the VG30DE were thoroughly reviewed and revised. The VG30DETT engine is the result of redesigning the structure of the engine itself and its parts and components to assure durability under, high-level performance requirements.

A robotic driver has been designed on the basis of an analysis of a human driver's action in following a given driving schedule. The self-learning algorithm enables the robot to learn the vehicle characteristics without human intervention. Based on learned relationships, the robotic driver can determine an appropriate accelerator position and execute other operations through sophisticated calculations using the future scheduled vehicle speed and vehicle characteristics data. Compensation is also provided to minimize vehicle speed error. The robotic driver can reproduce the same types of exhaust emission and fuel economy data obtained with human drivers with good repeatability. It doesn't require long preparation time. Thereby making it possible to reduce experimentation work in the vehicle development process while providing good accuracy and reliability.

Driving tests were conducted using an experimental vehicle equipped with an adaptive cruise control system incorporating low-speed following capability in order to evaluate drivers' trust in a driver support system. The results revealed that the drivers' trust in the system declined in cases where the control algorithm produced vehicle behavior that was inconsistent with their expectations. However, that decline in trust ceased to be observed as the drivers' understanding of the system improved. This result suggests a correlation between their understanding of the system and trust in it.

A study was made on a control method for an adaptive cruise control (ACC) system that uses vehicle-to-vehicle communication to achieve a substantial improvement in string stability and natural headway distance response characteristics at lower levels of longitudinal G. A control system using model predictive control was constructed to achieve this desired ACC vehicle behavior. Control simulations were performed using experimental data obtained in vehicle-following driving tests conducted on a proving ground course using a platoon of three manually driven vehicles. The results showed that the proposed ACC system satisfactorily achieved higher levels of required ACC performance.

This paper concerns research on an emission control system aimed at reducing emission levels to well below the ULEV standards. As emission levels are further reduced in the coming years, it is projected that measurement error will increase substantially. Therefore, an analysis was made of the conventional measurement system, which revealed the following major problems. 1. The conventional analyzer, having a minimum full-scale THC range of 10 ppmC, cannot measure lower concentration emissions with high accuracy. 2. Hydrocarbons are produced in various components of the measurement system, increasing measurement error. 3. Even if an analyzer with a minimum full-scale THC range of 1 ppmC is used in an effort to measure low concentrations, the 1 ppmC measurement range cannot be applied when the dilution air contains a high THC concentration. This makes it impossible to obtain highly accurate measurements. 4.

Since the stable operating region of a gasoline-fueled HCCI engine is limited to the part load condition, a mode change between SI and HCCI combustion is required, which poses an issue due to the difference in combustion characteristics. This report focuses on the combustion characteristics in the transitional range. The combustion mode in the transitional range is investigated by varying the internal EGR rate, intake air pressure, and spark advance timing in steady-state experiments. In this parametric study, stable SI-CI combustion is observed. This indicates that the combustion mode transition is possible without misfiring or knocking, regardless of the speed of variable valve mechanism which includes VVA, VVEL, VTEC, VVL and so on, though the response of intake air pressure still remains as a subject to be examined in the actual application.

The probability or risk of traffic accidents must be estimated quantitatively in order to implement effective traffic safety measures. In this study, various statistical data and probability theory were used to examine a method for predicting the risk of crossing-collisions, representing a typical type of accident at intersections in Japan. Crossing-collisions are caused by a variety of factors, including the road geometry and traffic environment at intersections and the awareness and intentions of the drivers of the striking and struck vehicles. Bayes' theorem was applied to find the accident probability of each factor separately. Specifically, the probability of various factors being present at the time of a crossing-collision was estimated on the basis of traffic accident data and observation survey data.

A safety support system that uses information received from the road infrastructure is being developed in a project sponsored by the Ministry of Land, Infrastructure and Transport. The purpose of this system is to reduce the number of accidents at intersections and on highways. The system is now being tested in an experimental vehicle. This paper describes what kind of information is helpful to drivers based on the experimental results.

It is important to understand the influence of housing stiffness on bearing performance, particularly for the connecting rod bearings of automotive engines. It is known that the engine lubricant shows a piezoviscous characteristic whereby its viscosity changes under the influence of pressure. Engine bearings under a heavy load are apt to be influenced in this way. In this study, the effects of connecting rod stiffness and lubricant piezoviscosity on bearing performance were examined by elastohydrodynamic lubrication (EHL) analysis under conditions corresponding to the high-speed operation of an actual engine. The results indicated that under such heavy load conditions housing stiffness greatly affects friction loss because of lubricant piezoviscosity. It was also found that the piezoviscosity of the lubricant has a large effect on bearing performance, as does its viscosity under atmospheric pressure.

The techniques harmonizing the contradiction which consists of exhaust noise reduction and engine power increase, have been required for the exhaust muffler. This techniques rapidly improved by means of the clarification due to the acoustic theories and the flow analyses. Recently, according to the passenger car tendency toward high grade and high performance, demands for low noise and high power exhaust systems are increasing year by year. The “Dual Mode Muffler” system (abbreviated, below, DMM) mounted on Nissan Cedric, Grolia and Cima series, installed in 1987, is achieved the consistent of the quietness and the engine power performance. This system is the first control type exhaust system for the 4 wheel car. On previous paper, the analyses of acoustic characteristics on DMM were mainly shown. The analyses of exhaust pressure characteristics are also an important theory along with the acoustic in the development of the exhaust system.

This paper describes a newly developed adaptive cruise control (ACC) system using continuously variable transmission (CVT) gear ratio control. This system provides excellent headway distance control performance at a reasonable cost. With this system, headway distance is measured with a laser radar, and the throttle position and CVT gear ratio are controlled under both acceleration and deceleration situations. The new ACC system consists of a target headway distance calculator, a headway distance controller, a vehicle velocity controller and a drive torque controller. Using a drive torque control method that was newly developed based on integrated control of engine torque and the CVT gear ratio, the following benefits are obtained. (1) It provides smoother acceleration and deceleration. (2) It maintains the target vehicle velocity on steep uphill and downhill grades. As a result, sufficient ACC performance can be attained even in 2.0-liter class vehicles.

In order to calculate efficiently the characteristics of car body vibration and the acoustic characteristic of the passenger compartment, a structural-acoustic analysis system, ‘CAD-B’, was developed. This system divides the body into three components - front body, main cabin and rear body. The characteristics of front and rear body vibration are expressed in modal parameters. The vibration characteristic throughout the car body is then calculated through the building block approach, while the main cabin remains in finite elements. A good agreement in eigen pairs was seen between this approach and the conventional finite element method. As for the passenger compartment, it is divided into finite elements and its eigen pairs are calculated. Then by linking body vibration with the acoustic characteristic of the passenger compartment, sound pressure in the passenger compartment is calculated.

In making driver workload assessments, it is important to evaluate the driver's level of brain activity because the operation of a motor vehicle presumably involves higher-order brain functions. Driving on narrow roads in particular probably imposes a load on the driver's brain functions because of the need to be cognizant of the tight space and to pay close attention to the surroundings. Test vehicles were fitted with a functional near-infrared spectroscopy (fNIRS) system for measuring bloodstream concentrations at 32 locations in the frontal lobe of the participating drivers in order to evaluate their levels of mental activity while driving on narrow roads. The results revealed significant increases in cerebral blood flow corresponding to the perceived workload. This suggests that increases in cerebral blood flow can be used as an effective index for estimating mental workloads.

A new integrated control system has been developed for controlling an SI engine and a CVT proactively so as to obtain the demanded drive torque most efficiently. Taking into account ease of calibration, a control system configuration has been achieved that determines the CVT ratio from the target drive torque and vehicle speed, based on the steady-state relationship between the demanded drive torque and the vehicle speed, gear ratio, engine torque and fuel economy. An analysis was made of drive torque characteristics while the ratio was changing under transient conditions. The results showed that using engine torque to compensate for the ratio change response lag and inertia torque, which is proportional to the differential of the gear ratio, is effective in improving drive torque responsiveness.

For the purpose of protecting the driver from injury in a crash, a safety standard has been established that specifies the allowable impact force when the driver hits the steering wheel as a result of an impact. In this work, an investigation was lade of steering column collapse behavior in which the steering column was constructed such that the crash energy was absorbed by the bending and tearing of a thin steel plate. As a result, a finite element analysis method has been developed for conducting an impact analysis using a ductile fracture model of the thin plate. This method makes it possible to predict the collapse behavior of the steering column and the deceleration that develops on the body block of the safety standard test model.

Eight rollover research tests were conducted using the 2001 Nissan Pathfinder with a modified FMVSS 208 dolly rollover test method where the driver and right front dummy restraint performance was analyzed. The rollover tests were initiated with the vehicle horizontal, not at a roll angle. After the vehicle translated laterally for a short distance, a trip mechanism was introduced to overturn the vehicle. Retractor, buckle, and latch plate performance in addition to the overall seat belt performance was analyzed and evaluated in the rollover test series. Retractor pretensioners were activated near the rollover trip in three of the tests to provide research data on its effects. Various dummy sizes were utilized. The test series experienced incomplete data collection and a portion of the analog data was not obtained. National Automotive Sampling System (NASS) data was also analyzed to quantify the characteristics of real world rollovers and demonstrated the benefits of restraint use.

Automotive electronic control systems have tended to become more complex in recent years as a result of stronger requirements for environmental friendliness and higher levels of driveability. The first step in developing a control system is to study the required logic and system configuration at the initial stage of new vehicle development. The authors have incorporated an engine-vehicle model in a control system CAD program to simulate the logic needed for various control tasks. This paper presents a typical application in which a behavior of some outputs, such as engine torque and acceleration, was analyzed, and the electronic controls needed to assure driveability were identified. The construction and operation of a controller-in-the-loop system are also described.

An automatic, falling, occupant-protecting net is being developed for spreading in front of automobile occupants in the time interval between vehicle impact and occupant collision. The device is designed to counteract forward body acceleration and minimize head, neck, and chest injuries. This device was investigated by sled and barrier tests using anthropomorphic dummies. Significant improvements in occupant kinematics and remarkable reduction in head and chest impact force has been observed. Some problems such as whiplash injury await solution but continuing investigation of proposed measures of correction show that they are not insurmountable.