An occupant position sensor is the key device for the smart airbag system to increase the reliability of conventional airbag systems. In the smart airbag system, the degree of airbag explosion is controlled by the data from the occupant position sensor. High accurate occupant position sensing is needed, which might be difficult by supersonic technologies.
This paper reports a novel optical occupant position sensing device suitable for the smart airbag system, which measures the distances from the sensor to 2 dimensional multiple points on the occupant. The method to measure the distances is optical triangulation using photo-diode array pairs and a data processing IC.
In this paper. the occupant position recognition is demonstrated using the data obtained by 2 dimensional distance measurement of the occupant position sensing device, in the accuracy of 3cm at the distances of 75cm within the optical view angle of 35 and 53 degrees in horizontal and vertical respectively. Total distance measurement points of this device are 4×44. This paper also describes the recognition possibility of 4 basic occupant position using these distance data, which is needed for airbag explosion control in smart airbag system.

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A superconducting milli-sized linear actuator has been developed. The superconducting actuator consists of a high T_c superconducting slider, electromagnets for driving and levitation, power amplifiers, control circuits and a personal computer with a PIO interface board. The superconducting slider has a concave - convex pattern with a pith of 3mm and the stator has electromagnets with 1.0mm pitch. The electromagnetic forces can levitate and drive the superconducting slider with 4 driving phases. In this paper, various kinds of driving methods are proposed and the best driving method is selected for the actuator. From the results, it is found that just one driving method is useful for the actuator, because the superconducting slider can return to the stable position that corresponds to the driving phase. Using the driving method, the superconducting slider can move in the speed range less than several centimeters per second.

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In an electrostatic microstructure with a movable electrode supported by a cantilever beam and counter electrodes, voltage dependency of displacement of the movable electrode is studied by taking surface force into consideration. The displacement change is analyzed theoretically with the energy model which determines the stable displacement state of the movable electrode from the minimum energy state of the total energy of elastic energy, electrostatic energy and adhesion energy between two surfaces. The relation between the surface force at contact parts of the movable electrode with the counter one and a hysteresis voltage of capacitance (between the both electrodes)-voltage characteristics (C-V characteristics) was investigated and a magnitude range of the surface force in which stiction of the movable electrode occurs is derived. In an experiment which simulated electrical contacts of the electrostatic microstructure with charged objects, the surface force increased with increase of the charge amount of the object. In measurements of C-V characteristics in positive and negative voltage regions, the C-V characteristics shifted to the positive voltage region and the shift was larger in a device with larger surface oxide layer of the movable electrode. This voltage shift is thought to be caused by a positive electrical charge remaining in the oxide layer.

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This paper proposes a velocity field sensing system using a conventional color TV camera and a trichrome stroboscope that sequentially flashes three different color lights within a frame interval. The key consideration is the distinct separation of three sequential images from a mixed RGB image. The three sequential images can then be processed for velocity field extraction. We assume that any targets or flow markers have a uniform color. A procedure for determining mixture matrix A, which plays a crucial role in the separation, is presented and some requirements on A for inversion are discussed. Experimental results show that this method successfully decomposed an RGB image of a fast rotating object and extracted the velocity field from the separated image sequence. Practical issues-automatic adjustment of the flash interval to the object's speed and applicability of this method-are also discussed.

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This paper describes a fiber optic oxygen sensor using fluorescence and its application to clinical examinations. The quenching ratio of fluorecence is proportional to oxygen partial pressure by the Stern-Volmer's formula by which the oxygen concentration is possible to estimate from measured emission intensity. We have fabricated a microscopic luminous probe using Solvent Green 5 doped plastic optical fiber coupler. A microscopic luminous probe was experimentally investigated as an oxygen sensor in visible light. In addition, we have clarified various characteristics of this sensor.

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We have newly developed Lift-Off patterning process at the bottom of a deep pit. This process consists of fabricating positive photoresist profiles with overhangs using a sacrificial Aluminum layer in order to form precisely thin film electrode patterns. Using this process, the thin film deposited on the photoresist can be completely separated from the other portions of the thin film deposited on the substrate. Au/Pt/Ti thin film electrodes which are 750nm thickness in total can be obtained at the bottom of a pit which is 30 μ m depth without any defects by realizing overhanging edges which are 800nm height and 8 μ m undercut. The deflection of pattern width of Au/Pt/Ti thin film electrodes is under ±3 μ m.

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Thermal interaction between a micro-flow sensor and the air flow around it was investigated. At a higher flow velocity. the Navier-Stokes' equation, coupled with the heat-conduction equation of the sensor, was solved. The heat-transfer coefficient by the simulation was roughly equal to the one calculated from the forced convection heat transfer theory. At the zero flow velocity, the interaction between the sensor and the air was simulated by FEM. The heat energy from the sensor to the air was almost fixed at the heat conductivity of the air multiplied by the temperature gradient of the sensor from the silicon plate. At a lower air flow velocity, the thermal sensitivity of the sensor nearer to the silicon plate is limited.

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Discrimination of odorous materials by the quartz resonator sensors with synthetic lipid membranes was investigated. Using five sensors with various membranes. we measure responses to five odorous materials which were included in the T&T olfactmeter for testing a human olfactory sense. Discrimination from the patterns of the sensors response were difficult. because the patterns were similar. We apply a principall component analysis to the sensor responses. The result was largely influenced by the concentrations of the odorous materials. With a discriminant analysis, the five odorous materials were found to be well discriminanted, even though the concentrations were different. We also found that the time constants of the sensor responses were also good parameters for discrination and it enables to shorten the time for measurement.

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