Hiroo Iwata

This paper proposes a representation method for volumetric data using both an immersive projection display and a haptic device. The aim of using an immersive display is not only an increase of information for the viewer, but also to present him/her to the spatial structure of volumetric data. Haptic sensation also helps the user to manipulate the data. Using the haptic device further enables the user to observe an accurate volumetric images. In this paper, to evaluate this method, we developed a prototype system that consists of a spherical immersive display and a haptic display. Then we compared the system with other test environments which use a HMD (Head Mounted Display) or a large plain screen. After these comparisons, we confirmed that the method is more effective to manipulate the data than the methods used in the other environments.

Audio Haptics is a rendering technique for auditory and haptic sensations. Sound and force are generated by using a physical model of virtual objects. We developed a software for real-time calculation of a physical model of virtual objects. A speaker is set at the grip of the haptic interface for spatial localization of the sound.

This paper describes development of a haptic display that displays 3D shape in real environment using an air-balloon array. The device employs many small balloons arranged by cubic array. It enables user whole palm interaction; not only touch virtual objects but also to hold them. We developed a balloon control unit that control the volume of the balloon and evaluated it. Then we constructed a balloon array using 5 control units and created some sample shapes of virtual object.

This paper describes development of a haptic display that displays 3D shape in real environment using an air-balloon array. The device employs many small balloons arranged by cubic array. It enables user whole palm interaction; not only touch virtual objects but also to hold them. We developed a balloon control unit that control the volume of the balloon and evaluated it. Then we constructed a balloon array using 5 control units and created some sample shapes of virtual object.

This paper reports about omni-directional stereoscopic images on a spherical immersive display. The display has an advantage that the direction of binocular disparity is constant. We examined basic performance of stereoscopic viewing of this display. Then we implemented and examined the method which enables us to generate stereo images without tracking of viewer's direction.

This paper reports about omni-directional stereoscopic images on a spherical immersive display. The display has an advantage that the direction of binocular disparity is constant. We examined basic performance of stereoscopic viewing of this display. Then we implemented and examined the method which enables us to generate stereo images without tracking of viewer’s direction.

This paper reports about omni-directional stereoscopic images on a spherical immersive display. The display has an advantage that the direction of binocular disparity is constant. We examined basic performance of stereoscopic viewing of this display. Then we implemented and examined the method which enables us to generate stereo images without tracking of viewer's direction.

We have developed a rotational high-resolution video image display. This display is designed to be combined with omni-directional locomotion interface named Torus Treadmill.The display consists of 9 projection screens and 9 CCD cameras. The 9 CCD cameras are designed to have the same optical center, by using plane mirrors. The display provides 135 degree horizontal and 105 degree vertical video image. In order to trace rotational motion of the viewer, this display is installed on a turntable. In this way, surrounded high-resolution video image was virtually realized.

This paper describes design of array force display for presentation of hardness distribution in an elastic object. The array force display is composed of an elastic plate and a linear actuator array. It provides a spatially continuous surface on which users can effectively touch virtual objects using any part of their bare hand. The elastic plate is made of rubber and sponge. When the actuator pushes the plate, its hardness increases. The user feels as if hard object is submerged in a soft object. The device is evaluated through experiments for palpation performance.

This paper describes a rehabilitation system using network-connected locomotion interfaces. We developed two footpad type locomotion interfaces that enable the users to feel the sense of walking on uneven virtual terrain and connected them via network. Using this system, the patient can feel the motion of walking from the movements of the footpads under his/her feet. Also the therapist can teach the motion of walking to the patient directly by only walking on the interface, and adjust his/her walking motion according to the patient condition. We implemented a master-slave environment and evaluated the system. We also discussed other types of rehabilitation environment using our system.

Visual immersion plays an important roll in virtual environment. Ensphered Vision is an image display system for wide-angle spherical screen. Sphere is an ideal shape of a screen that covers human visual field. Distance between eyes and screen should be constant while a viewer rotates the head. We use single projector and a convex mirror in order to display seamless image. The optical system employs two mirrors: a plain mirror and a spherical convex mirror. The spherical convex mirror scatters the light from the projector in the spherical screen. The plain mirror provides the viewer to the sweet spot where he/she can see image from the center of the sphere. This optical configuration enables seamless wide-angle image in a very limited space. This paper presents history and current research activities of the Ensphered Vision.

This paper proposes a representation method of volumetric medical data by using a surrounded display and a haptic display. The viewer is entirely surrounded by a spherical screen which projects volumetric medical data. Also the viewer can explore and interact with the data by using a haptic display. In this paper, we introduce two devices; an immersive projection display called Ensphered Vision and a haptic display named Haptic Master. Then we illustrate the method of representation the data with these devices. Finally the effect of the representation is discussed.

Virtual reality lab at University of Tsukuba is situated in Tsukuba city, 60km northeast from Tokyo, Japan. Since 1986, we have been studied on virtual reality such as haptic interface, locomotion interface, spherical screen and their applications. This overview summarizes the key areas of our research in virtual reality.

This paper proposes a representation method for volumetric data using both an immersive projection display and a haptic device. Our method provides virtual microscopic views and miniaturized interactions inside the volumetric data. We configured the visual/haptic system based on our methods and implemented a CT image of a human brain to the system. We then examined the navigation performance and exploration efficiency throughout the system. These examinations confirmed that both the wide-angle view and haptic representation improved the performance.

This paper presents work carried out for a project to develop a new interactive technique that combines haptic sensation with computer graphics. The project has two goals. The first is to provide users with a spatially continuous surface on which they can effectively touch an image using any part of their bare hand, including the palm. The second goal is to present visual and haptic sensation simultaneously by using a single device that doesn't oblige the user to wear any extra equipment. In order to achieve these goals, we designed a new interface device comprising of a flexible screen, an actuator array and a projector. The actuator deforms the flexible screen onto which the image is projected. The user can then touch the image directly and feel its shape and rigidity. Initially we fabricated two prototypes, and their effectiveness is examined by studying the observations made by anonymous users and a performance evaluation test for spatial resolution. © 2001 ACM.

This paper describes an arrayed fore display that presents kinetic rigidity distribution. The device simulates hard objects underneath a soft surface. This device employs an elastic surface made of rubber and sponge. An array of linear actuators is set under the surface. Pressing the elastic body by the actuators, the rigidity distribution of the surface can be changed. We analyze the performance of the device through measurements of rigidity and psychophysical tests.

Visual immersion plays an important roll in virtual environment. Ensphered Vision is an image display system for wide-angle spherical screen.Sphere is an ideal shape of a screen that covers human visual field. Distance between eyes and screen should be constant while a viewer rotates the head. We use single projector and a convex mirror in order to display seamless image. The optical system employs two mirrors : a plain mirror and a spherical convex mirror. The spherical convex mirror scatters the light from the projector in the spherical screen. The plain mirror provides the viewer to the sweet spot where he/she can see the image from the center of the sphere. This optical configuration enables seamless wide-angle image in a very limited space.

This paper describes software architecture for integration of interface devices. Interface devices, such as haptic interface, are implemented in various configurations. In most cases, software of virtual environment is tightly connected to control program of those interfaces. This problem is a hazard for development of advanced applications. This paper proposes a modular software architecture called IOA (Interaction-oriented Architecture), which supports various types of interface devices. Sensors and displays are easily reconfigured by exchanging modular software. The IOA also supports tools for content development. Implementation of IOA is exemplified through audio haptics and networked haptics.

Currently most of virtual reality system with auditory feedback can produce good feel of presence to the users. In VR (Virtual Reality) environment, interactions with virtual objects are common events. Some systems provide sounds generated by interactions between virtual objects, although they are generated using modulation technique of prerecorded sounds. There is a limitation in that method. We should consider the sound generation method based on physical models. In this paper, we propose a method of synthesis haptic and auditory senses that is based on physical model. We have developed an auditory environment with haptic sensation. We equipped a speaker at the end eifecter of the HapticMaster. The FEM (Finite Element Method) is used to calculate the vibration of the virtual object. And the sound pressure data at the speaker position are calculated based on the vibration in real time. The effectiveness of our method is tested through the experiments by users.

Currently most of virtual reality system with auditory feedback can produce good feel of presence to the users. In VR(Virtual Reality) environment, interactions with virtual objects are common events. Some systems support sounds generated by interactions between virtual objects, although they are generated using modulation technique of prerecorded sounds. There is a limitation in that method. We should consider the sound generation method based on physical models. In this paper, we propose a method of synthesis haptic and auditory senses that is based on physical model. We have developed an auditory environment with haptic sensation. We equipped a speaker at the end effecter of the HapticMaster. The FEM(Finite Element Method) is used to calculate the vibration of the virtual object. And the sound pressure data at the speaker position are calculated based on the vibration in real time. The effectiveness of our method is tested through the experiments by users.

Currently most of virtual reality system with auditory feedback can produce good feel of presence to the users. In VR(Virtual Reality)environment, interactions with virtual objects are common events. Some systems support sounds generated by interactions between virtual objects, although they are generated using modulation technique of prerecorded sounds. There is a limitation in that method. We should consider the sound generation method based on physical models. In this paper, we propose a method of synthesis haptic and auditory senses that is based on physical model. We have developed an auditory environment with haptic sensation. We equipped a spearker at the end effecter of the HapticMaster. The FEM(Finite Element Method)is used to calculate the vibration of the virtual object. And the sound pressure data at the speaker position are calculated based on the vibration in real time. The effectiveness of our method is tested through the experiments by users.

"ANOMALOCARIS" is an interactive work, which represents virtual creature through visual and haptic sensation. Anomalocaris is a name of an animal that supposed to live during the Cambrian Era. Virtual anomalocaris is displayed on the HapticScreen. HapticScreen is a new configuration of a force feedback device. HapticScreen has an innovative mechanism that creates sense of touch on whole palm. The device deforms itself to present shapes of virtual object. Typical force feedback device uses a grip or thimble. On the other hand, users of HapticScreen can touch virtual object without wearing anything. HapticScreen employs a flexible screen made of cloth. Video image is projected on the flexible screen so that the participant can directly touch the image and feels its rigidity. Actuators are set under the screen, which make deformation. Original HapticScreen employs 36 linear actuators set at an array of 6 x 6. The screen deforms by the actuators. Each actuator has a force sensor. Hardness of the screen is variable by these actuators and sensors. We have developed a simplified and robust mechanism of HapticScreen for the exhibition at the Ars Electronica Center.

This paper presents a new locomotion interface device for walking about virtual space. Traveling on foot is the most intuitive way for locomotion. An infinite surface driven by actuators is an ideal device for creation of sense of walking. We selected a torus-shaped surface to realize the locomotion interface. The locomotion device employs twelve sets of treadmills. These treadmills are connected sideby-side and driven in perpendicular direction. The effect of infinite surface is generated by the motion of the treadmills. The walker can go in any direction while his/her position remains localized in the real world. The device is applied to study of human performance on spatial recognition

This paper describes a software tool for construction of a virtual environment with sense of move. A locomotion interface is implemented in various mechanical configurations. In most case, the software of the virtual environment is tightly connected to the control program of the locomotion interface. This problem is a hazard for development of further applications. We developed a modular software tool called LHX-L, which supports various type of locomotion interface. LHX-L is composed six modules. Application of the locomotion interface is easily reconfigured by exchanging these modules. The effectiveness of LHX-L is exemplified through various applications.

This paper describes locomtion interface that presents uneven virtual surface. The term "haptics" is currently being generalized beyond just hand-object interaction. One of the new frontiers of haptic interface is full-body haptics that includes foot haptics. Force applied to a foot is essential in walking on uneven virtual surface, such as staircases. We developed a 4DOF motion platform for each foot. Two motion platforms move according with positon of the feet. These devices are mounted on a turn table, which rotates the devices according with rotation of the body. This mechanism simulates omni-directional uneven surface.