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The almost current sound localization methods do not have enough resolution in low frequency sound localization. To overcome this disadvantage, I am now developing the new sound localization method, Double Nearfield Acoustic Holography (DNAH) method. This method is a converted method of conventional Nearfield Acoustic Holography (NAH) method. In this proposing method, the resolution of low frequency sound localization is improved by using sound propagation information on doubled measurement planes. To prove the performance of proposing method, the basic experiments with variable conditions are conducted. In these experiments, the small speakers are used as sound sources. In this paper, to discuss the ability to apply to actual industry, the effect of measurement distance from the sound source is explained. Some experimental results with changing measurement distance are shown in this paper.

The sound localization methods are used for detection of noise source locations of prototypes of mechanical products including automobile engines. There are several types of sound localization methods. In middle frequency around 1kHz, which is most sensitive frequency for human auditory, these sound localization methods have enough resolution in their reconstructed images, and they are effective to localize the sound sources. For high frequency sound localization, the holographic type methods take long time in its measurement. To overcome this problem, I have developed a converted method of Nearfield Acoustic Holography (NAH) method, which is one of conventional holographic sound localization method. However, in low frequency, all holographic localization methods do not have enough resolution in reconstructed images. I am now developing new sound localization method, Double Nearfield Acoustic Holography (DNAH) method. This method is converted method of conventional NAH method.

Nowadays the quality competition in automotive industry becomes notably higher. And in the noise and vibration field, the necessity of troubleshooting to trial products is emphasized. As a sound localization method, which is used for sound sources detection for trial products, the Acoustic Intensity method is widely used in automobile industry. On the other hand, the Nearfield Acoustic Holography method is not spread in actual automotive industry because of its troublesomeness of measurement in high frequency. In this paper, the converted NAH method, which uses the extra spatial spectrums, is explained. This method realizes the reduction of measurement time to the same level with Acoustic Intensity method. In this paper, the theory of this converted method and some numerical simulations are explained.

A new approach of modeling is put forward to representing functions of clutch and brake directly, and their functional models are proposed in this report. Rotary motion is the most important type of motion for transmitting the kinetic energy, so many rotary parts and apparatus, for example the crutches and brakes, are used in most of machines. It is difficult to model function of the rotary element directly without relying on its structure by the conventional modeling approaches, for example the finite element method. The basic concept of the proposed approach is introduced, and the functional models of the hydraulic clutch with multiple plates, the clutch with vibration absorbing mechanism, the disc brake and the band brake are presented. Simulation results verify validity and usefulness of the proposed approach.

To shorten the term of automobile development, recently the numerical experimental systems are focused as the compensation methods of real experimentations. These systems are based on the accurate modeling method, and simulate actual motions of mechanism sufficiently accurate to predict the results of actual experimentation and to be the alternative of it. The automobile mechanisms involve various nonlinierity in its motion because of its complex mechanic structure, fluid existence and thermo utilization nature. Therefore the modeling method applied to automobile mechanism is particularly required the accuracy on nonlinear action. There were mainly two modeling method well known. One is the Bondgraph method which simulate energy flow of dynamic system. As the all physical phenomenon is recognized as embodiment of energy behavior, this method is to be excellent in accuracy as calculation of physical phenomenon.

An approach of modeling is put forward for automobile product development, and a concept of a functional model is proposed in this paper. Functional models of mechanical, electrical and fluid systems of single degree of freedom are introduced. A wiper system and a power train system are modeled using this approach, and hierarchical functional models of these systems are presented. Simulation result with the hierarchical functional model is compared with test result using an actual power train system of passenger car in order to verify validity and usefulness of the proposed approach.