Tokuhiro Sugiura

Figure and texture presentation capabilities of a tactile mouse equipped with a display pad of stimulus pins

To obtain specifications for a tactile display that would be effective in virtual reality and tele-existence systems, we have developed two types of matrix-type experimental tactile displays. One is for virtual figures (display A) and the other is for virtual textures (display B). Display As pad has a 4 × 6 array of stimulus pins, each 0.8 mm in diameter. Three pad configurations, in which distances between any two adjacent pins (pin pitch) are 1.2, 1.9, or 2.5 mm, were developed to examine the influence of distance on a human operators determination of virtual figures. Display B has an 8 × 8 array of stimulus pins, each 0.3 mm in diameter and with 1-or 1.8-mm pin pitch, because presentation of virtual textures was presumed to require a higher pin density. To establish a design method for these matrix-type tactile displays, we performed a series of psychophysical experiments using displays A and B. By evaluating variations in the correct answer percentage and threshold caused by different pin arrays and different pin strokes, we determined under what conditions the operator could best feel the virtual figures and textures. The results revealed that the two-point threshold should be adopted as the pitch between pins in the design of the tactile display, that a pin stroke should exceed 0.25 mm, and that the adjustment method is the most appropriate to evaluate the capabilities of tactile displays. Finally, when we compared the virtual texture with the real texture, we found that the threshold for the real texture is almost 1/3rd that of the virtual texture. This result implies that it is effective to present variations in patterns caused by rotation and variation in shearing force, itself produced by relative motion between the finger surface and object surface.

An Indicating, Leading Manipulator as a Good Hand at Teaching Strokes: A Mental-Image-Creation Support System.

A mental image creation support system was developed. The mechanical device of the system is a 3-DOF manipulator that is composed of a 2-DOF quadrilateral parallel-link manipulator and an arm-end actuator. A couple of servomotors drive a couple of upper links of the 2-DOF manipulator, and they control the arm-end position. The arm-end actuator is attached to the 2-DOF manipulator’s arm-end: a servomotor controls the orientation of a knob attached to the servomotor axis. The person is assumed to pinch the knob by his/her fingertips. The position of the knob axis traces the strokes of the presented figures sequentially, and the orientation of the knob is controlled to indicate the orientation of the currently tracing point on the stroke. A couple of preeminent functions are embedded to the process: one is the indicating function, and the other is the leading function. That is, the knob indicates to the person with its orientation to which direction the arm end moves: the direction reflects the orientation of the ongoing stroke. And the translation of the knob leads the person along the strokes. The indicating/leading functions play complementary role. Thus, the person is able to perceive the position and the orientation of the strokes of presented images via somatic sensations of his/her fingertip. It is expected to be a good hand at teaching strokes and to be a visual alternative of the blind persons and a visual aid of lazy eye persons at creating mental images.

Dual Mode Fingertip Guiding Manipulator for Blind Persons Enabling Passive/Active Line-Drawing Explorations

A fingertip guiding manipulator was developed as a haptic graphic display to help the visually impaired create mental images of line drawings. The latest model to be presented in this study equips dual mode fingertip-guiding function allowing either passive or active exploration. When using this manipulator, the person is assumed to pinch a knob by his/her fingertip: the knob is attached at the end of the manipulator. In the active mode, the fingertip guiding manipulator pulls his/her fingertip along line drawings. In the passive mode, it provides a kind of selective compliance, and allows the persons freely to move his/her fingertip in the only direction of the line drawings. For the sake of the dual mode function, it is expected that efficiency would be improved a lot comparing to the former model being equipped with the passive mode alone.

Auditory Sensation Aided Image Perception: Integration of Somesthetic Sense of Fingertip Position

A color image presentation system with sound via touch-panel interface was developed and some perceptual characteristics with the system were studied in this paper. Each subject actively operates his/her fingertip on the touch panel interface, and the system returns syllable sounds corresponding to the colors nearby the fingertip position. Without sight, he/she perceives images through the sound information together with the fingertip positional sense. The authors carried out some preliminary psychophysical experiments on the human perceptual characteristics in converting speech sounds into image patterns and on the fingertip positional sense. Based on the results of the preliminary experiments, the authors developed a color image presentation system. It was confirmed through experiments using the system that the subjects were able to perceive the shapes of simple closed polygonal figures within 2 or 3 minutes.

Fingertip guiding manipulator: haptic graphic display for mental image creation

A fingertip guiding manipulator was developed as a haptic graphic display for blind people: it helps them create mental images of raised graphics and reliefs with stroke order. Through fingertip kinesthetic sense, while foreseeing the direction of the upcoming stroke by perceiving the knobs direction, users experience the uplifted and fallen strokes by perceiving their fingertips being pulled in the horizontal and vertical directions. Especially, the up-lifting function expands a representation capability from “single stroke graphics” to “multiple stroke graphics

Parametric eigenspace method using multiple discriminant analysis

Parametric eigenspace methods are well known appearance-based methods for object recognition, which involves object classification and pose estimation. However, ordinary parametric eigenspace methods consider only the expressive features, and they suffer from a problem arising from the fact that discriminative features are not considered. So, there have been developed some methods to construct such eigenspaces considering the discriminative features. However, the method might suffer from another problem, i.e., the so-called generalized eigenvalue problem: yet, we can manage to solve the problem. In this paper, two methods are referred to as representative methods considering discriminative features. Conducting an experiment of object recognition on two similar objects, performances of the methods are compared to one another, and a piece of important knowledge is also presented that the discriminative features are more effective than the expressive features.

J1601-1-1 A motion Instruction System Using Head Tracking Back Perspective

In the practice of sports, dances, etc., we learn postures or motions from visual information such as videos in many cases when we are not directly taught by an instructor. As their improvement, some systems in which a learner follows 3D CG target model have been proposed. However the method of 3D posture instruction is not established yet since the depth distance is not shown clearly and the viewpoint is not suitable. In this paper we proposed a posture instruction system that shows 3D human model CG on a HMD (Head Mounted Display) in the virtual space. Specifically, the system shows target model and current lecturers model on the HMD, being superimposed and it also shows such guiding objects as arrows. Furthermore, we proposed “Head Tracking Back Perspective” that trainees viewpoint follows head movement. The experimental results show that the system is effective to instruct static postures.

High performance file compression algorithm for video-on-demand e-learning system

Information processing and communication technology are progressing quickly, and are prevailing throughout various technological fields. Therefore, the development of such technology should respond to the needs for improvement of quality in the e-learning education system. The authors propose a new video-image compression processing system that ingeniously employs the features of the lecturing scene: recognizing the a lecturer and a lecture stick by pattern recognition techniques, the video-image compression processing system deletes the figure of a lecturer of low importance and displays only the end point of a lecture stick. It enables us to create the highly compressed lecture video files, which are suitable for the Internet distribution. We compare this technique with the other simple methods such as the lower frame-rate video files, and the ordinary MPEG files. The experimental result shows that the proposed compression processing system is much more effective than the others.

Design of Elliptic Gabor Wavelets with Triangular Lattice Configuration and their Application to Target Detection

This paper introduces elliptic Gabor wavelets with the triangular lattice configuration as a model-based target recognition approach. And, making the degree of overlap uniform between the neighboring Gabor wavelets in the frequency domain, it enables to cover the frequency space with higher density than the existing circular Gabor wavelets with square lattice configuration. Thus, it succeeds efficiently to extract a rotation and scale invariant features of the target objects. This paper, furthermore, presents some useful guidelines for designing system parameter values by a large amount of experiments, and shows effectiveness of the proposed method by comparing it with other methods.