Masafumi Takahashi

Noncontact Tactile Display Based on Radiation Pressure of Airborne Ultrasound

This paper describes a tactile display which provides unrestricted tactile feedback in air without any mechanical contact. It controls ultrasound and produces a stress field in a 3D space. The principle is based on a nonlinear phenomenon of ultrasound: Acoustic radiation pressure. The fabricated prototype consists of 324 airborne ultrasound transducers, and the phase and intensity of each transducer are controlled individually to generate a focal point. The DC output force at the focal point is 16 mN and the diameter of the focal point is 20 mm. The prototype produces vibrations up to 1 kHz. An interaction system including the prototype is also introduced, which enables users to see and touch virtual objects.

Touchable holography

Mid-air displays which project floating images in free space have been seen in SF movies for several decades [Rakkolainen 2007]. Recently, they are attracting a lot of attention as promising technologies in the field of digital signage and home TV, and many types of holographic displays are proposed and developed. You can see a virtual object as if it is really hovering in front of you. But that amazing experience is broken down the moment you reach for it, because you feel no sensation on your hand.

Remote measurement of surface compliance distribution using ultrasound radiation pressure

In this paper, we propose a remote measurement system of surface compliance distributions for haptic broadcasting. Our system is composed of an ultrasound phased array generating acoustic radiation pressure on the remote object surface and a laser displacement sensor. The compliance is evaluated by the ratio of the surface displacement to the applied force. We set up a system to examine the feasibility of the method. In the experiments, the distribution of the surface compliance comparable to the human skin was successfully measured for a flat object surface.

Development of robotic TV game player using haptic interface and GPU image recognition

“RoboGamer” is a robotic system which is able to play a video game togather with a human player. In previous computer game systems, the computers are always designed as enemies to the human. However, in this project, we realized a physically connected friendly computer player by a simple robotic system that is composed of a video camera, wire based force feedback display SPIDAR and a program that made with GPU fast image recognition without any modification for original video game system. RoboGamer has three functions that are autonomous play, augmented effects like force feedback and/or rich graphics for original old video game and collaboration play with A.I. and human player via force feedback on the joystick.

A new real-time video synthesis method for virtual studio environments using GPU and projected screens

This paper describes a new supportive information projecting technique for virtual TV studio environments with a back projected screen which is not visible for the audience, but visible for actors. Traditional TV studios use blue or green back chroma-key for video composition, thus the actors cannot see the final composite without the preview monitor. When the actors point or watch a point on the background image, they need an extensive experience or rehearsals. In our system, the actors can see and point the supportive information displays; such as computer generated background, virtual actors, scripts and/or final composites around them.