We propose a novel wearable haptic interaction system that delivers a realistic haptic feedback from virtual objects in midair. We evaluated the recognition ability of virtual objects through encounter, contour following, and pinch behaviors by using our proposed finger-worn haptic display, and then confirmed that the high-accuracy representation of the position and size makes a stable feeling of existence of the virtual object even in the air. Our proposed method can be used in entertainment, telecommunication, and virtual reality systems.

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Under a remote collaboration, a teleoperated laser pointer is applied as an instruction tool to indicate real-world objects in a real work space. Ubiquitous devices mounting a teleoperated laser pointer make telecommunications smooth. However, this method has a difficulty identifying the indicated object in the situation that the laser-spot is occluded behind indicated object itself or other objects. In this paper, we propose a method, that is visualizing the light path of a laser with jetting mists along the light axis, to remedy the difficulty. It is expected that the worker can estimate the indicated object from visible light path laser pointer. We conducted experiments to evaluate our method on the condition that the instructor and the worker exist face-to-face. The result shows that the estimation accuracy of the position of a laser-spot occluded behind an object is improved with visualizing the light path of the laser.

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In this research, we propose the analysis method of visual and haptic information flow in human central nervous system by using a wearable haptic display for hairy skin of human arm. This display can produce haptic stimulation on the hairy skin of human arm by using DC motors. In the evaluation experiment, we used the virtual reality system with physical mass-spring-damper calculation, and controlled virtual arm with mechanical haptic display and motion capture system.

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This paper describes a new method of measuring user's position for location-based services in wide indoor environments. Conventional localization methods usually employ a hybrid approach in which user's position is estimated by combining positioning infrastructures and a pedometer. Since the installation cost of infrastructures increases when the area expands, the measurement of user's relative position with high accuracy is required. This paper proposes a new localization method for a walking or running user by measuring user's orientation and geometrical relationship between user's heel and waist with an orientation sensor and an electromagnetic tracker that are attached to user's body. Experiments have been carried out using a prototype system to evaluate the accuracy of user localization with the proposed method.

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We propose a system design including the architecture, data flows, and communication protocols etc. to realize a seamless multi-display environment (MDE). Our interaction architecture combines distributed input and position tracking data to generate perspective-corrected output in each of the displays, allowing groups of users to manipulate existing applications from current operating systems across a large number of displays. To test our design we implemented a complex MDE prototype and measured different aspects of its performance. Then we discuss the results of the measurements and the potential availabilities.

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Vection is an illusory motion perception of the body induced by visual motion stimuli. Recent brain-imaging studies emphasized the contributions of relatively high-level brain areas in vection induction. However, Gurnsey et. al. (1998) suggested involvements of lower-level motion processing by using psychophysical analyses. In this study, we examined the involvements of low-level visual system quantitatively by using 2f+3f stimuli (Nishida & Sato, 1995, where high-level and low-level motion move simultaneously in opposite directions). These stimuli enabled us to compare the contributions of both high-level and low-level motion signals to vection. Results showed the stronger vection inductions by low-level motion signals regardless of the balance between the motion signals of the two types. These results strongly suggest the importance of low-level visual processing in vection induction.

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In this research, we developed a real-time fluid simulator for graphic and haptic interfaces to display a virtual environment including 3-dimensional fluid by using smoothed particles hydrodynamics (SPH). SPH is a type of particle method and is suitable for a fast computation; however, it is difficult to incorporate sufficient fluid incompressibility in SPH for simulating a real-time process. This is because SPH was originally developed to study compressible fluid dynamics. In this paper, we propose a new control method using nonlinear feedback to compensate for elements that interfere with incompressible motions and propose its implementation method that does not significantly increase the computation time. Finally, simulations are performed to compare the proposed method with a conventional method, and the effectiveness of the proposed method is quantitatively demonstrated from the standpoints of computation time and incompressibility.

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