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1 Attenuation of acoustic noise from automobile components is important for passenger comfort. Since the alternator is one of the major sources of noise, many manufacturers have studied the various mechanisms which generate noise within an alternator as well as the methods to reduce the noise level. This paper presents the dynamic properties of the alternator with respect to the acoustic noise during current generation, and introduces a vibration damping structure based on experimental modal analysis. Rotating magnetic forces in a magnetic circuit (stator and rotor) can excite numerous structural resonances, resulting in acoustic noise. A modal analysis performed on the major magnetic circuit of the alternator (Nippondenso Co., Ltd.) revealed that the stator has elliptic, triangular and rectangular mode shapes in the radial coordinate plane, while the rotor does not have any significant resonances in the same 0 - 3 kHz region.

Environmental control of the passenger compartment has become increasingly important and sophisticated. One major consideration of interior comfort is clean, healthful, aromatic air. Accordingly, two new products were developed to increase the dust removing and deodorizing effects. These are the “Air Purifier” and the air conditioner ventilation filter called the “Air Refiner”. The Air Purifier affects the air inside the vehicle, and the Air Refiner affects the air from outside the vehicle. Remarkable effects are achieved by employing a newly developed material called “Impregnated Activated Carbon Fiber (IACF)” which is utilized in both the Air Purifier and the Air Refiner. In addition to the air purification system, a new fragrance control system called the “Aroma Controller” was developed. The Aroma Controller allows the user to select from three aromatic fragrances. The fragrance is emitted intermittently by way of “1/f fluctuation control” via microcomputer control.

Recently, an increasing demand for comfort has been accelerating the trend toward multifunctional car air conditioners, including zone air conditioning which controls the cabin temperature independently for the driver and the passenger and compensates for the side solar radiation. In addition, the multifunctional air conditioner should be compact to save cabin space and ensure passenger comfort. This report describes the development of a compact and multifunctional car air conditioning unit.

EMI suppresion capacitors and filters are common in automobile electronics today, but they are insufficient for heavy concentrations of wideband electromagnetic radiation. To resolve this problem, a highly-integrated Ceramic Absorber was developed to efficiently shield against frequencies from 1MHz to 1000MHz, which is mountable on the control circuit board easily, as it is the form of a flat plate strip line. This filter provides the signal line with an electromagnetic absorption effect through line transmission characteristics. Research into ceramic materials was required to determine the specific dielectric constants and frequency characteristics of ferroelectric ceramic materials. The development objective was material with optimum dielectric dispersion, as determined from research into energy absorption based on the Debye dielectric dispersion theory.

During motor vehicle operation, the image processing and pattern recognition of various external visual information to assist human vision is an effective method to improve safety and driving comfort. Research into image processing and pattern recognition, supported by advancing device and computer technology, is entering the age of practical application. Against this background, we have developed a system to visually detect, recognize and transmit to the vehicle operator road signs, which are definable patterns, as the first step in the application of image processing and pattern recognition technology to the automotive sector. The major points of this system are as follow: 1. A color processing system was adopted which reduces the effects of brightness and shadow, and implemented in dedicated hardware. 2. The development of dedicated hardware for template matching enables the real-time extraction and processing of defined patterns within the image.