Seikoo Suzuki

Highly reliable silicon micromachined physical sensors in mass production

Abstract Silicon micromachined physical sensors such as silicon pressure sensors and accelerometers are now in mass production in response to the strong market demands. In the design of such sensors, it is most important to guarantee high reliability as well as low cost. To respond to these demands for microsensors, the designs of device structure, production processes and packaging have been investigated in detail.

Thick-Film Zirconia Air-Fuel Ratio Sensor with a Heater for Lean Mixture Control Systems

This paper describes the design and operation of a thick-film zirconia air-fuel ratio sensor with a heater. This sensor is composed of two zirconia plate cells, a stoichiometric cell and a lean cell, laminated on the platinum heater. It is fabricated as one body using a thick-film process. The pair of cells has a gas diffusion chamber and a slit type gas diffusion aperture. The sensing principle is based on the rate-determining diffusion of oxygen molecules at the gas diffusion aperture. By using an oxygen pumping phenomenon, air- fuel ratios of the stoichiometric and lean regions can be detected. As this sensor is heated to a high constant temperature, it has sufficient accuracy without any additional temperature compensation. Its starting time is short and response time is very quick.

Recent developments of optical fiber sensors for automotive use

Abstract Optical fiber sensing technologies are expected to apply for many future electronic control systems in automobiles, because of their inherent outstanding features, such as high noise immunity, high heat resistance, and flexible light propagation paths which can be applied to measure the movements and directions of the mobiles. In this paper, two typical applications of fiber sensing technologies in automobiles are described in detail. The combustion flame detector is one of the typical applications of a fiber spectroscopic technology which utilizes the feature of high noise and heat resistibility and remote sensibility. Measurement of engine combustion conditions, such as the detonation, the combustion initiation, and the air-fuel ratio, have been demonstrated in an experimental fiber sensing method. Fiber interferometers, such as a fiber gyroscope, have great possibilities in future mobile applications because they are applicable to many kinds of measurements for movements and physical variables...

Recent Developments Of Optical Fiber Sensors For Automotive Use

Optical fiber sensing technologies are expected to apply for many future electronic control systems in automobiles, because of their original outstanding features, such as high noise immunity, high heat resistance, and flexible light propagation paths which can be applicable to measure the movements and directions of the mobiles. In this paper, two typical applications of fiber sensing technologies in automobiles have been described in detail. The combustion flame detector is one of the typical applications of a fiber spectroscopic technology which utilizes the feature of high noise and heat resistibility and remote sensibility. Measurements of engine combustion conditions, such as the detonation, the combustion initiation, and the air-fuel ratio, have been demonstrated in an experimental fiber sensing method. Fiber interferometers, such as a fiber gyroscope, have a lot of possibilities in future mobile applications because they are expandable to many kinds of measurements for movements and physical variables. An optical fiber gyroscope utilizing the single polarized optical fiber and optical devices has been developed. Quite an accurate measurement of vehicle position was displayed on a prototype navigation system which installed the fiber gyroscope as a rotational speed sensor.

The Role of Sensors and Sensing Technology for Future Automotive Systems

The role of sensors and sensing technologies for the next generation vehicle systems are discussed. The control systems for engines and power-train are expected to realize high efficiency with low pollution and comfort driveability. Vehicular safety and chassis control systems are expected to avoid many kinds of traffic accidents caused by the human errors of drivers. Vehicular information systems will help the drivers to get the information to manage their vehicles economically and efficiently. In every system mentioned above, sensors and sensing technologies are playing an increasingly important role. This paper introduces and discusses essential technologies for sensors and sensing which can be expected to bring the solutions to the future automotive systems.