Showing papers in "Jsae Review in 1995"
254 citations
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TL;DR: In this article, a new concept of radar brake system with an automatic braking function is reported, which consists of three key technologies: (1) Scanning laser radar sensor; (2) Algorithm for judging potentiality of collision; (3) Control-by-wire brake system.
Abstract: This paper reports on a new concept of radar brake system with an automatic braking function. Similar systems developed for collision-avoidance have been reported. Their method of operation is based on the timing required to avoid collisions solely by braking function. However, the distance between two cars that is required to avoid collision by using steering is shorter than that required by braking alone. Thus, a serious unresolved problem is the driver's sense that the braking function alone can lead to inappropriate timing. For instance, in the case where the driver recognizes an on-coming obstacle and is able to avoid it by using steering, the system operates prior to his action and the driver is disturbed. This system consists of three key technologies: (1) Scanning laser radar sensor; (2) Algorithm for judging potentiality of collision; (3) Control-by-wire brake system.
76 citations
TL;DR: In this paper, the authors developed computer programs that analyze the transient heat transfer and the transient thermal stress of Functionally Gradient Materials (FGM) by the finite element method (FEM).
Abstract: Composite materials made of ceramics and metal are already used in heat resistant parts, such as pistons. Functionally gradient materials (FGM) are new composite materials that reduce the thermal stress caused by the difference of thermal expansion and that are resistant to super high temperature. In order to support the design of FGM, we have developed computer programs that analyze the transient heat transfer and the transient thermal stress of FGM by the finite element method (FEM). In this paper, the thermal stress analysis by these programs of an FGM plate, composed of Zr0 2 and Ti-6A1-4V, is discussed.
73 citations
Journal Article•
TL;DR: In this article, the phase plane method was used to evaluate the vehicle stability in critical cornering with the application of a direct yaw moment control system, taking into account the vehicle side slip angle and angular velocity as the state variables.
Abstract: This paper presents discussions on the vehicle cornering stability in critical cornering, using the \"Phase-Plane Method\" which takes into account the vehicle side slip angle and its angular velocity as the state variables. In addition, the potential for the enhancement of the vehicle stability in critical cornering with the application for a direct yaw moment control system is also presented.
56 citations
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43 citations
32 citations
TL;DR: In this article, an investigation was made of the effects of intake valve closing timing on the spark-ignition engine combustion when the closing timing was varied for the purpose of reducing pumping loss.
Abstract: An investigation was made of the effects of intake valve closing timing on the spark-ignition engine combustion when the closing timing was varied for the purpose of reducing pumping loss. It was found that the principal cause of combustion deterioration was a drop in cylinder gas temperature and pressure, which was traced to a decline in the effective compression ratio and to a reduction in EGR gas and residual gas fraction. It was also observed that increasing the residual gas fraction worked to mitigate the deterioration of combustion.
29 citations
TL;DR: In this article, the authors investigated the relationship between the oil consumption and oil ring movement and found that the two-ring piston is thinner than that of the three ring piston due to the greater amount of blowby through the piston.
Abstract: This study was aimed at clarifying the characteristics of oil film thickness, piston friction and oil consumption in the two-ring piston. Through experimental studies it was found that the oil film thickness of the two-ring piston is thinner than that of the three-ring piston due to the greater amount of blowby through the piston. As a result, increase of oil consumption of the two ring piston was kept to the low level of the conventional three ring piston. A quantitative analysis on the friction force and the relationship between the oil consumption and oil ring movement were carried out using the unique measuring device developed by the authors.
28 citations
TL;DR: In this article, the relation of rear-end shape to drag and lift is studied by consideration of the wake structure, which is obtained by wind tunnel testing and CFD, and a new rear shape which reduces rear lift without increasing drag and front lift is discussed.
Abstract: The rear-end shape of a car is one of the most important parts from the view point of aerodynamics. It governs the aerodynamic characteristics of the car, especially drag and rear lift. However, a rear-end shape like a spoiler often increases drag on recent low-drag cars. In this paper, the relation of rear-end shape to drag and lift is studied by consideration of the wake structure, which is obtained by wind tunnel testing and CFD. Finally, a new rear shape which reduces rear lift without increasing drag and front lift is discussed.
27 citations
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25 citations
TL;DR: In this paper, the authors developed a system which measures the blinking duration of a driver by processing his facial image and estimates his drowsiness level. But this system is not suitable for the detection of road traffic accidents.
Abstract: The purpose of this study is to detect the drowsiness of drivers to prevent traffic accidents. We have developed a system which measures the blinking duration of a driver by processing his facial image and estimates his drowsiness level. This paper presents an imaging unit which is less affected by ambient light, a method of measuring the driver's blinking duration which is independent of his facial features, and a method of estimating his drowsiness level from a change in his blinking duration.
TL;DR: In this article, the torque transmitting mechanism of a CVT metal pushing type belt was investigated by theoretically analyzing working forces on steel bands and blocks, and the relation between belt slip limit and pulley clamping force was derived with enough accuracy for practical use.
Abstract: This paper investigates the torque transmitting mechanism of a CVT metal pushing type belt by theoretically analyzing working forces on steel bands and blocks. Measuring these working forces, the drive model presented in this paper is shown to be appropriate. Applying this analysis, the relation between belt slip limit and pulley clamping force is derived with enough accuracy for practical use.
TL;DR: In this paper, a thin film pressure sensor made of manganin was developed by means of sputtering, which was formed directly on the sliding surface of a plain bearing, and oil film pressure measurement during engine operation was carried out successfully.
Abstract: In this study, a thin film pressure sensor made of manganin was developed by means of sputtering. The sensor was formed directly on the sliding surface of a plain bearing, and oil film pressure measurement during engine operation was carried out successfully. The formation method and characteristics of the sensor are presented in this paper, together with the measured data, taking account of instantaneous temperature fluctuation occurring during one cycle and deformation of the bearing, which would cause measurement error.
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Journal Article•
TL;DR: In this article, a road surface recognition method using an optical spatial filter is proposed and the optical sensor is also capable of detecting ground speed, which can be used for road surface classification.
Abstract: In this paper, a novel road surface recognition method using an optical spatial filter is proposed. The optical sensor is also capable of detecting ground speed.
Journal Article•
TL;DR: In this paper, the authors describe the computer simulation of a bus rollover test and show that 42% of the initial potential energy was absorbed as plastic deformation and the remaining 58% was dissipated as elastic energy.
Abstract: This paper describes the computer simulation of a bus rollover test. First, as a base, a live rollover test was conducted and the mode of deformation was studied. Next, window pillar test pieces were impact tested for absorbed energy characteristics. These impact tests were then simulated with the LS-DYNA finite element (FE) code LS-in order to study efficient and accurate modelling techniques. Applying the knowledge gained, a complete bus structure involving shells, beams and rotational springs was developed and a rollover test was simulated. The simulation results compared well with the live test results in both deformation mode and amount of deformation. From this simulation, it was determined that 42% of the initial potential energy was absorbed as plastic deformation and the remaining 58% was dissipated as elastic energy. The results confirmed the usefulness of the busmodel. (A) For the covering abstract of the conference see IRRD 894848.
TL;DR: In this article, a double structure combustion chamber known as Caldera was developed for DISC engines, which made possible a perfect unthrottling operation, and a fuel consumption equal to a diesel engine.
Abstract: A new combustion method for DISC engines was developed. It has a double structure combustion chamber known as “Caldera”. This method makes possible a perfect un-throttling operation, and a fuel consumption equal to a diesel engine is achieved. In the output of the DISC engine, a stoichmetric combustion and a high torque are achieved by controlling the fuel injection timing with an electro-magnetic injection device. With regard to emission regulations, a heavy EGR including residual gas greatly decreases NOx and HC emissions simultaneously.
TL;DR: In this article, the platinum ion-exchanged ZSM-5 zeolite catalyst (Pt-5), which reduces nitrogen oxides (NOx) in the presence of oxygen and hydrocarbons, was applied to actual diesel engine exhaust.
Abstract: The platinum ion-exchanged ZSM-5 zeolite catalyst (Pt-5), which reduces nitrogen oxides (NOx) in the presence of oxygen and hydrocarbons, was applied to actual diesel engine exhaust. Compared to the Cooper ion-exchanged ZSM-5 zeolite catalyst, the Pt-Z had higher NOx reduction efficiency, ηNOx = 33%, and lower activation temperature, 250°C, in normal engine operation. It was found that water in the exhaust gas did not apparently affect the NOx reduction, while the reduction efficiency was significantly affected by the aspect ratio of the catalyst reactor and by the shape of the catalyst, i.e. pellet or honeycomb.
TL;DR: In this article, a blowby sampling device was used to obtain samples for measuring the sulfate ion concentration in the blowby condensate and it was found that sulfate ions, which cause corrosive wear of diesel engines, are produced by water vapor and SO x present in gases in the combustion chamber during the compression stroke.
Abstract: This paper presents an analysis of the mechanism whereby sulfate ions are produced and intermix with the crankcase oil. A blowby sampling device was used to obtain samples for measuring the sulfate ion concentration in the blowby condensate. It was found that sulfate ions, which cause corrosive wear of diesel engines, are produced by water vapor and SO x present in gases in the combustion chamber during the compression stroke. It was also found that sulfate ions intermix with the oil on the cylinder bore during the compression stroke.
TL;DR: In this article, a method to express the concept of load transfer and the course of the transferred load in the structure is introduced, and the degree of joint stiffness between the members of the vehicle body can also be discussed based on this concept.
Abstract: A method to express the concept of load transfer and the course of the transferred load in the structure is introduced. Transferred load in an actual passenger car body is investigated experimentally. The degree of joint stiffness between the members of the vehicle body can also be discussed based on this concept. Difference can be shown between the course from the front suspension and that from the rear suspension under the condition of the torsional loading.
TL;DR: In this article, the effect of clearance between the liner and the block, and in particular the mechanism of thermal deformation, were found through measurement of bore deformation by using a unique measuring device, which has a turning piston developed by the authors, and through FEM calculation.
Abstract: Cylinder bore deformation of reciprocating engines causes increasing lubricating oil consumption, abnormal wear, etc. However, prediction of deformation on a dry liner has not been made because of the complication of its structure. This study investigates the mechanism of dry liner deformation in actual engine operating conditions. The effect of clearance between the liner and the block, and in particular the mechanism of thermal deformation, were found through measurement of bore deformation by using a unique measuring device, which has a turning piston developed by the authors, and through FEM calculation. Lubricating oil consumption related to bore deformation was also studied.
TL;DR: In this article, the authors describe new viewpoints for the evaluation of human interfaces of in-vehicle information systems and investigate the drivers' characteristics in the cases of using a navigation system and a paper map.
Abstract: This study describes new viewpoints for the evaluation of human interfaces of in-vehicle information systems. Firstly, by using quantitative analysis, the drivers' characteristics were compared and investigated in the cases of using a navigation system and a paper map. The results show that it is difficult to clarify what caused the difference of drivers' behavior. A new framework which includes methods based on cognitive science was introduced and the drivers' behavior was investigated using the framework. The results indicate that it is important to investigate the driver's cognitive process and that this framework is effective for evaluation of the human interface.
TL;DR: In this paper, the authors have theoretically analyzed the characteristics of the sources of aerodynamic noise and have succeeded in clarifying the relationships between the flow patterns and noise properties, which has been confirmed both in wind tunnel test and on road test.
Abstract: Along with improved quietness in vehicles in recent years, aerodynamic noise reduction has been demanded strongly. Actions concerning the noise generating source analysis are important. To study the direction for aerodynamic noise reduction, we have theoretically analyzed the characteristics of the sources of aerodynamic noise. As a result, we have succeeded in clarifying the relationships between the flow patterns and noise properties; the resulting aerodynamic noise reduction has been confirmed both in wind tunnel test and on road test.