Terunao Hirota

Wireless network system for indoor human positioning

A local positioning system utilizing propagation loss of Bluetooth wireless technology is developed for indoor human positioning. The distance between a fixed station and a mobile station carried by a person is derived from the propagation loss. The position of the person is calculated from distance measurements on three different fixed stations. The positioning accuracy was 1.2 m at average fixed station installation density of one station in every 8.3 m/sup 2/. The system is intended for tracking workers position in a work environment such as in shipyards.

ANALYTICAL AND EXPERIMENTAL MODELING OF INTRA-BODY COMMUNICATION CIRCUIT

ABSTRACT Intra-body communication uses human body as the propagation medium. This may become a new wireless communication method for Personal Area Network (PAN) with less power consumption and higher communication security compared to conventional RF methods. A common analytical model of intra-body communication is a combination of capacitive coupling among the human body, electronic devices, and the environment. Experimental results suggest that there are optimal parameters for transmission. We assume that it is a combination of not only the capacitive couplings, but also of a radio wave transmission and of imbalances in the electrical impedances among the transmitter/receiver electrodes attached to the human body.

DEVELOPMENT OF LOCAL POSITIONING SYSTEM USING BLUETOOTH

ABSTRACT A local positioning system utilizing propagation loss of Bluetooth wireless technology is presented. The distance between a stationary station and a mobile station (both located indoor) carried by a person is derived from the propagation loss. The position of the person is calculated from distance measurements on three different fixed stations. The positioning accuracy was 1.2m at average fixed station installation density of one station in every 8.3m2. The system is intended for tracking workers position in a work environment.

Flexible monolithic optical head slider combined with visible laser light guide for first surface optical recording

Optical near-field recording is a candidate technology for overcoming the diffraction limit of conventional optical recording. In our previous work, we proposed a novel optical head slider for near-field recording that we call a flexible optical head slider. An air-bearing pad pattern is formed on the apex of a cantilever-like polymeric waveguide so that, by using the cantilever itself as the slider suspension, a single body structure incorporates the functions of the flying slider, suspension, and waveguide. This structure can be expected to provide several important advantages by miniaturizing head assemblies; simplifying the assembly and optical trimming processes; and producing a lighter head, thus allowing a wider tracking bandwidth. In our previous report, the mechanical characteristics and readout signal characteristics of the flexible head slider were evaluated. In this paper, we studied the tracking control for the flexible optical head slider. To detect tracking errors, a T-shaped aperture was used. One straight part of the T-shaped aperture was set along the edge of the tracks, so the transmitted light from this part is sensitively affected by off-track displacement. Another straight part is used for readout of the data marks. The T-shaped aperture was formed through the metal layer deposited on the slider pad surface, at the end of the waveguide core, using FIB (focused ion beam) etching. Test ROM media with repeated pattern of 0.5 micron-sized dot marks was used to evaluate the position error signal.

A novel approach to optical first-surface recording based on thin film gas-lubricated slider bearing technology

This paper describes a novel approach to first-surface optical recording based on a gas-lubricated flying head slider mechanism which is commonly used in hard disk drives. To avoid the usage of complex optical elements including lenses, mirrors, and prisms, we have introduced a plastic resin - based optical wave-guide which also functions as a flying head suspension and/or slider shoes. Several types of recording head mechanisms are referred to.

Simulative Experiment on Precise Tracking for High-Density Optical Storage Using a Scanning Near-field Optical Microscopy Tip

This paper describes simulative experiment of sub-micron region tracking control for a near-field optical disk storage, utilizing a scanning near-field optical microscopy (SNOM) tip as a highly sensitive head. A continuous tracking error detection model was introduced, and evaluated its equivalent tracking performance experimentally. Sub-sub-micron aperture heads tracking error arising from an electrical and an optical noises could be suppressed to several nanometers assuming that head operating spacing is maintained less than 50 nm and tracking control bandwidth is limited to 5kHz. The results showed that we could estimate the tracking error due to the noise derived mainly from the opto-electonic conversion system. In this simulative experiment, the optical efficiency of the head was relatively small compared with that of the planer or tapered type aperture; thus, the result should be regarded as an under-estimation. The optimization of the sensor location for more efficient data detection, and the more practical evaluation of a tracking control system considering the actuator characteristics are problems that remain to be studied in future.

Motion planning and control method of dexterous manipulation utilizing a simulation system for a multi-fingered robotic hand

This chapter presents the manipulation of a block and a cylinder on a table with a two-fingered robotic hand was presented. Nine types of primitive motions are defined for this manipulation. The joint trajectories and contact forces were generated by the simulation system that we developed in the previous work. For the control of primitive motions involving estimation of the direction of the kinematic constraint, four active sensing methods were developed. Force sensors and dynamic tactile sensors are used to adapt to uncertainties encountered during manipulation. The change in the contact force vector was used to estimate the contact location on the table, and the small variation in the fingertip position was used to refine the accuracy of the estimate. Experimental results of various manipulative motions have proved that complex manipulations can be realized as sequences of primitive motions.