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The series-parallel hybrid electric vehicle(HEV), which employs a planetary gear set to combine one internal combustion engine(ICE) and two electric motors(EMs), can take advantages of both series and parallel hybrid system. The efficient powertrain operating point of the system can be obtained by the instantaneous optimization of equivalent fuel consumption. However, heavy computational requirements and variable constraints of the optimization process make it difficult to build real-time control strategy. To overcome the difficulty, this study suggests the control strategy which divides the optimization process into 2 stages. In the first stage, a target of charge/discharge power is determined based on equivalent fuel consumption, then in the second stage, an engine operating point is determined taking power transfer efficiency into account.

Mathematical modeling of three-way catalytic converter (3WCC) operation is used increasingly in the optimization of automobile converter systems. But almost all of previous computational models were based on "adiabatic one- channel" approach with the reaction kinetics computations, which is useful and efficient in predicting real-world performance of the catalyst. However, as long as flow maldistribution is not accounted for in the models, simulation results will not be reliable. In this work, two-dimensional performance prediction of catalyst coupled with turbulent reacting flow simulation has been performed and the results were compared with experimental data and one-channel simulation in the literature. The computational results from this study show the better prediction accuracy in terms of CO, HC and NO conversion efficiencies compared to those of 1-D adiabatic model. Varying cell density and hot spot moving pattern within the monolith during warm-up period are also considered.

The purpose of this study was to develop a new element removal method for ESO (Evolutionary Structural Optimization), which is one of the topology optimization methods. ESO starts with the maximum allowable design space and the optimal topology emerges by a process of removal of lowly stressed elements. The element removal ratio of ESO is fixed throughout topology optimization at 1 or 2%. BESO (bidirectional ESO) starts with either the least number of elements connecting the loads to the supports, or an initial design domain that fits within the maximum allowable domain, and the optimal topology evolves by adding or subtracting elements. But the convergence rate of BESO is also very slow. In this paper, a new element removal method for ESO was developed for improvement of the convergence rate. Then it was applied to the same problems as those in papers published previously.

Vehicle collisions frequently happen at a low-speed. Insurance companies and the RCAR (Research Council for Automobile Repairs) require reducing repair costs and improving occupant safety in a low-speed crash. In order to reduce repair costs in the RCAR test conditions, an energy absorbing device such as the crash box (C/Box) is usually installed. The C/Box is a thin-walled structure attached between the vehicle bumper structure and the side rail. The determination of the C/Box geometry is quite important to absorb the impact energy since the installation space of the C/Box is not very large. In this research, the determination process for the cross-sectional dimensions is proposed to improve the energy absorption efficiency of the C/Box. The proposed process has two steps. First, the cross-sectional dimensions are determined by two ways. One is a parameter study using an orthogonal array and the other is topology optimization.

This paper proposes a parking assist system that fuses around view monitor (AVM) image, ultrasonic sensor, and in-vehicle motion sensor. The proposed system recognizes various types of parking slot markings using AVM image sequences and classifies occupancies of the detected parking slots using ultrasonic sensors. Once a desirable parking slot is selected by a driver, its position is continuously tracked by fusing AVM images and motion sensor-based odometry. Experimental results show that the proposed system can reliably detect and track various types of parking slot markings.

An optimization program for the design of wiper linkages is developed to minimize jerky motion while satisfying design constraints on kinematic and torque performances, mobility condition, and packaging. The lengths/orientations of links and the position of a driving motor are selected as design variables. In our optimum design program for wiper linkages, an optimization module interacts with an analysis module which calculates kinematic and force/torque properties, until convergence. The optimization results of a particular wiper linkage are presented to illustrate the effectiveness of the program developed.

In the methodology to measure the vehicle-following distance, the general trend is to use a pulsed laser system combined with the high resolution counter to estimate the flight time of laser pulse reflected from the forward vehicle. But in this method, the resolution of distance measurement is limited by the counter resolution. In this paper, an alternative method to measure distance and relative velocity with fairly high accuracy, which uses the integration of the time delay between transmitted and received pulses and its A/D conversion. By using this method, we can improve the distance measurement resolution up to a centimeter unit and this satisfies our purpose.

This paper reports an automatic method for creating test cases for hardware-in-the-loop (HIL) testing of the body control module (BCM) for automobiles. First, test cases are generated automatically using Unified Modeling Language (UML) modeling software with an automatic test generation add-on. In this work, Rhapsody from IBM with the automatic test generator (ATG) add-on is used to generate automatic test cases. Then, these test cases are converted into Extensible Markup Language (XML) Metadata Interchange (XMI) format. From this XMI format file, test cases for HIL are generated by mapping stimuli such as digital input/output, analog input/output, and controller area network (CAN) interfaces. For this mapping procedure, the pros and cons of Extensible Stylesheet Language Transformations (XSLT) and XML Query Language (XQuery) are discussed.

The electrical power system is the vital lifeline to most of the control systems on modern vehicles. The demands on the system are highly complex, and a detailed understanding of the system behavior is necessary both to the process of systems integration and to the economic design of a specific control system or actuator. The vehicle electric power system, which consists of two major components: a generator and a battery, has to provide numerous electrical and electronic systems with enough electrical energy. A detailed understanding of the characteristics of the electric power system, electrical load demands, and the driving environment such as road, season, and vehicle weight are required when the capacities of the generator and the battery are to be determined for a vehicle. An easy-to-use and inexpensive simulation program may be needed to avoid the over/under design problem of the electric power system. A vehicle electric power simulator is developed in this study.

The effects of tumble flow generated by various intake ports on the lean burn characteristics in a four-valve pentroof engine were investigated. Tumble intensities were tested for three intake ports of different entry angle; 25°, 20° and 15°. The flow characteristics in cylinder were measured under motored conditions with laser Doppler velocimetry. The lean burn performances were examined in an operating 4-cylinder engine. The combustion duration under lean mixture conditions were calculated by heat release analysis of the pressure trace. The flame developments in a single-cylinder optical engine were visualized with an image-intensified CCD camera to see the effect of different flow patterns with three inlet ports of strong and weak tumble. It was found that there is a correlation between the stronger tumble during induction and the higher convective velocity and turbulence levels at the time of ignition, which result in faster and stable combustion under lean mixture conditions.