Hiroo Iwata

This paper describes development of a small and high-resolution surface type haptic display. This device consists of 64 (8×8) linear actuators that are set with no space between them. Each linear actuator consists of a lead screw, a DC servomotor, and a force sensor. It has ability to present arbitrary force and shape by changing its length interactively. The size of its base is 4mm (width) × 4mm (depth), therefore, the device is practicable to present high resolution force rendering. Some rigidity distribution rendering algorithms were evaluated through experiments.

There has already been progress in the development of unmanned construction and inspections of structures on land, mainly because it is possible to use radio waves and optical images that are effective ways to remotely control work and operate robots. In contrast it is not easy to develop unmanned work methods for use underwater, because it is a special work environment, where underwater turbidity and suspended solids obstruct the operator's view of the object of work by scattering light. This report introduces the remote operation of an underwater backhoe based on bilateral operation that was developed to overcome such difficulties.

Operation of the man-machine interface should be easy and intuitive for efficient works when using a remote-controlled underwater backhoe. Moreover, operation is preferable to be unwearying. Tiredness in the operation of the backhoe front part by the similar-figure-interface becomes a serious matter of concern in the site experiment of an underwater backhoe. The aim of this research is to evaluate the operativeness of the joystick-type-interface that is newly proposed. The operativeness of the joystick and that of the similar-figure-interface were compared in the pointing experiment.

Powered Shoes is a locomotion interface using roller skates actuated by two motors with flexible shafts. The device is light-weighted and wearable. It enables the user to walk in virtual environment while his/her position is maintained. The user can walk in arbitrary direction in virtual environment.

This paper describes development of a high-resolution surface type haptic interface. This interface consists of 64(8 8) linear actuators. Each linear actuator is set with no space between them and coilsists of a lead screw, a DC servomotor, and a force sensor. It has ability to present arbitrary force at arbitrary position by changing, its length interactively. Since the size of its base is 4mm (width) X 4mm (depth), the interface is practicable to present high resolution rigidity distribution. Some rigidity distribution rendering algorithms were proposed and evaluated through experiments.

Volflex is a volumetric haptic display. It is composed of a group of air balloons controlled by computer-controlled air cylinders. Each air cylinder is equipped with a pressure sensor that detects force applied by the user. Deformation occurs according with hardness of the virtual clay.

This paper describes image projection to the volumetric haptic display. The volumetric haptic display can represent a physical characteristic of 3-D virtual objects, such as shape and elasticity, as a real object in the real world. We try to project image around this 3-D object with using projector and create integrated environment that contains haptic information and visual sense, but there are two problems. One is distortion of the image on the screen, and the other is that the image has been projected on the user's hand during interaction. These problems destroy the feeling of unity in the haptic information and visual sense. To solve them, we approached distortion collection method using simulator and image extraction method using rotary mechanical shutter. Experimental result shows that these methods enable more natural projection.

We developed a spherical immersive projection display, a new model of EV(EnspheredVision). This display consists of spherical screen, plane mirror, convex mirror, six projectors and mechanical shutter. Multiple projector enables to improve the image resolution and brightness as compared with the former EV. Observer can watch the 360 degree panoramic stereo image using liquid crystal shutter glasses.

This paper discusses a new concept named "device art." The recent decades has shown significant advance in the interactive artwork created in Japan. Those artworks employ innovative interface devices. Device art has different characteristics from western art; bottom-up creation process, playfulness, and commercialization. Traditional Japanese culture, such as tea ceremony or flower arrangement, uses sophisticated devices, which are roots of device art.

This paper describes a haptic rendering method for perception of rigidity distribution using a tool-handing type haptic interface. Since the data of rigidity distribution is different from cardinal number data measured with CT or MRI, we can only perceive rigidity value only when we deform it. We developed a rigidity data mapping method like a spring model by considering cross-section of 3D rigidity distribution. We confirmed that our method is effective for rigidity distribution perception.

The CirculaFloor project was initiated to develop compact hardware for the creation of an infinite surface for walking and scalable hardware architecture for future system improvement. Thus, a configuration for locomotion interface using a set of omnidirectional movable tiles was developed. The method of circulating the movable tiles was divided into two phases: detection of walking and circulation of movable tiles. The resultant system provides a sense of walking and can thus potentially revolutionize the user experience in entertainment and training simulators.

This paper describes sensory integration using the Food Simulator. A taste of a food arises from mixture of auditory, chemical, and force sensation. The food simulator generates a food texture according to the force profile captured from a user's biting force of a real food. By development of the Food Simulator, we can extract only texture from taste. We experimented in sensory integration by displaying texture, sound, smell and taste. Our goal is to study integration among sensory modalities regarding a taste of a food.

In this paper, a system integrated haptic and audio sensation called AudioHaptics was proposed. It can generate those senses by using not pre-recorded sound but a physical model and by using a haptic interface (HapticMaster) that is equipped with a speaker at the end effecter. By using this system, the user can recognize inner structure, hardness, and quality of material. By the way, we usually rely on visual sensation mainly on recognition of object, and it is known as visual dominance. In this paper, auditory and haptic sensations were focused on. In particular, the effect between auditory and haptic sensations on user's perception of the hardness of a virtual surface was investigated. As a result, haptic dominance was confirmed as using auditory and haptic sensation.

This paper presents two methods for developing full-surround displays: rear-projection-based "Garnet Vision" and specialized spherical screen named "Ensphered Vision." The Garnet Vision is a closed polyhedron screen. A viewer stands inside the polyhedron so that image covers full solid angle around the viewer. Optimum configuration of polyhedron is determined by two criteria: pixel efficiency and space efficiency. The criteria maximizes space utility of the display. Through examination of these criteria, rhombic dodecahedron is chosen. A dodecahedron screen with twelve projectors is built, in which a viewer can stand. Ensphered Vision is an image display system for full-surround 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 flat 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 sensory integration using the food simulator. A taste of food arises from mixture of auditory, chemical, and force sensation. The food simulator is a haptic interface that can generate a force to user's teeth when the user bites a food. It consists of a film-like force sensor and one degree-of-freedom manipulator. The food simulator generates a food texture according to the force profile captured from a user's biting force of a real food. Then the profile of the biting force is replayed by controlling the reaction force of the device. By development of Food Simulator, we can extract only texture from taste. We experimented in sensory integration using texture, sound, and the taste. Our goal is to study integration among sensory modalities regarding a taste of food.

This paper describes development of a linear actuator for small and high-resolution surface type haptic display. This actuator consists of a lead screw, a DC servomotor, and a force sensor. And it has ability to present arbitrary force and shape by changing its length. Especially, the actuator can display a soft object like sponge cake. The size of its base is 4mm (width) ×4 mm (depth), which is the smallest DC servo actuator in the world at this time. A small and high-resolution surface type haptic display can be developed with the actuators. The characteristics of this actuator, such as force resolution and preciseness of position control, and its force rendering algorism were evaluated through experiments.

The Food Simulator is a haptic Interface that presents biting force. The taste of food arises from a combination of chemical, auditory, olfactory and haptic sensation. Haptic sensation while eating has been an ongoing problem in taste display. The Food Simulator generates a force on the user's teeth as an indication of food texture. The device is composed of four linkages. The mechanical configuration of the device is designed such that it will fit into the mouth, with a force sensor attached to the end effecter. The Food Simulator generates a force representing the force profile captured from the mouth of a person biting real food. The device ha been integrated with auditory and chemical display for multi-modal sensations in a taste The Food Simulator has been tested on a large number of participants. The results indicate that the device has succeeded in presenting food texture as well as chemical taste.

In this paper, we propose a method for the synthesis of haptic and auditory senses that is based on a physical model called AudioHaptics. We have developed a haptic environment that incorporates auditory sensation. We achieved this by fitting a speaker at the end effecter of a haptic interface. The FEM (Finite Element method) was used to calculate the vibration of a virtual object when an impact is occurred, and the sound pressure data at the speaker position was then calculated based on the 2D complex amplitude of the object surface in real time. The AudioHaptics system can generate sounds originating from virtual objects, which can have arbitrary shapes, attributes and inner structures. Experiments for evaluation with real users demonstrated that this method is effective for rendering audio and haptic sensation.

This article proposes a method of enabling users to share the sensation of walking with each other in a virtual environment (VE). Achieving this shared sensation requires physical equipment, with algorithms to control it. As an example of such physical equipment, a new footpad type of locomotion interface (LI), named GaitMaster2, has been developed and physiologically evaluated. An algorithm for the positional control of users' feet has been proposed, enabling the users to share various aspects of the sensation of walking. As an evaluation, two footpad type LIs were connected via a network. Using the proposed control algorithm, there followed the construction of a master-slave walking environment and a synchronized walking environment. These experiments demonstrated that this method is effective for sharing the sensation of walking in a VE.

A locomotion interface (LI) is a piece of equipment that can give a user the sense that he/she is walking while his/her actual position remains localized in the real world. We developed an LI system (GaitMaster2) that has two footpads, which can move to represent a virtual terrain for each user's foot. In this research, we applied our LI to gait rehabilitation. The footpads on our LI follow a pre-recorded motion sequence to move the user's feet. We conducted evaluation tests with the assistance of hemiplegic patients. The effectiveness of our system was verified through EMG, video analysis and the measurement of physical values such as average velocity. Copyright (C) 2003 John Wiley Sons, Ltd.

This paper describes development of a food simulator. A taste of food arises from mixture of auditory, chemical, and force sensation. This food simulator is a haptic interface that can generate a force to user's teeth when the user bites a food. It consists of a film-like force sensor and one degree-of-freedom manipulator. The food simulator generates a food texture according to the force profile captured from a user's biting force of a real food. Then the profile of the biting force is replayed by controlling the reaction force of the device.

The sense obtained by walking are vision and somatosensory. If we give a sense of walk in a virtual environment, we need these senses. This paper describes a construction of walk environment with vision and somatosensory. In order to construct this environment, we use two devices to present two senses. Using spherical immersive display, we provided vision. To make somatosensory, we used a locomotion interface. And we constructed a virtual walk environment, which those devices are combined.

港湾工事用水中バックホウは潜水士が作業現場に潜水して操作している。これに対して本研究では水中バックホウを海上から直感的に遠隔操作する為, バックホウと相似形状の力覚呈示装置を開発した。

In this research, we improve image resolutio of our spherical immersive display by using HDTV system. By using a HDTV projector and a HD camera unit, the system has approximately 3-times higher resolution than NTSC based spherical immersive display theoretically. Also the aspect ratio of HDTV (16:9) enhances the effective pixel ratio of original images that captured by the camera unit. We made a prototype system. We evaluated the effectiveness of this method by measuring subject's eyesight. As a result, we verified resolution enhancement with this system.

In this research, we improve image resolution of our spherical immersive display by using HDTV system. By using a HDTV projector and a HD camera unit, the system has approximately 3-times higher resolution than NTSC based spherical immersive display theoretically. Also the aspect ratio of HDTV (16:9) enhances the effective pixel ratio of original images that captured by the camera unit. We made a prototype system. We evaluated the effectiveness of this method by measuring subject's eyesight. As a result, we verified resolution enhancement with this system.

In human-scale virtual reality environment or augmented reality environment, force feedback plays important roll, as well as visual feedback. In such situation, force display requires large working volume and the ability to move easily. To satisfy these requirements , we've developed a non-grounded force display using gyro-moment effect. We measured various characteristics ,such as the threshold, the differential threshold. And we propose some techniques to indicate the information of territories or direction by using the force display. The effectiveness of this force display tested through some experiments and two applications.

This paper describes design of a surface type haptic interface for presentation of hardness distribution in an elastic object. The haptic interface 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. We analyze the performance of the device through measurements of rigidity and psychophysical tests.