With the growing presence of personal mobility vehicles and autonomous mobile robots in public spaces, pedestrian collisions have become an increasing concern, particularly because these devices operate quietly and often approach unnoticed. Traditional notification methods typically emphasize urgency through explicit and intense notifications, which often lead to psychological burden. To address this issue, this study proposes a method aimed at reducing sensory stimuli by using a virtual sound-absorbing wall. This approach leverages the human "obstacle sense", which is the ability to perceive objects based on changes in ambient sound blocked by their presence. A prototype system was developed in a virtual reality (VR) environment using a head-mounted display (HMD), where a virtual sound-absorbing wall appears in the direction of objects approaching from behind to enhance their perceived presence. The proposed method was compared to conventional notification methods in a VR environment, and its psychological impact was evaluated. Additionally, the impact of varying the angular width of the virtual sound-absorbing wall on detection rates was investigated. Results indicated that although the detection rate was lower than that of the conventional method, the proposed approach significantly reduced psychological burden. With the widest absorption angle condition, accuracy exceeding 90% was achieved in detecting the presence of the virtual sound-absorbing wall from directions other than directly behind.

This paper studies the characteristics of the human perception of a haptic shape-changing interface, capable of altering its size and rigidity simultaneously for presenting characteristics of virtual objects physically. The haptic interface is composed of an array of computer-controlled balloons, with two mechanisms, one for changing size and one for changing rigidity. We manufactured two balloons and conducted psychophysical experiments with twenty subjects to measure perceived sensory thresholds and haptic perception of the change of size and rigidity. The results show that subjects can correctly discriminate different conditions with an acceptable level of accuracy. Our results also suggest that the proposed system can present an ample range of rigidities and variations of the size in a way that is compatible with the human haptic perception of physical materials. Currently, shape-changing interfaces do not hold a defined position in the current VR / AR research. Our results provide basic knowledge for developing novel types of haptic interfaces that can enhance the haptic perception of virtual objects, allowing rich embodied interactions, and synchronize the virtual and the physical world through computationally-controlled materiality.

In this paper, we introduce LargeSpace, the world's largest immersive display, and discuss the principles of its design. To clarify the design of large-scale projection-based immersive displays, we address the optimum screen shape, projection approach, and arrangement of projectors and tracking cameras. In addition, a novel distortion correction method for panoramic stereo rendering is described. The method can be applied to any projection-based immersive display with any screen shape, and can generate real-time panoramic-stereoscopic views from the viewpoints of tracked participants. To validate the design principles and the rendering algorithm, we implement the LargeSpace and confirm that the method can generate the correct perspective from any position inside the screen viewing area. We implement several applications and show that large-scale immersive displays can be used in the fields of art and experimental psychology.

A block machine has been proposed as effective systems to support attack practice in volleyball. A method for manipulating the system by tablet operation has been established, and the use of the system has been shown to improve practice effectiveness. However, due to the requirement of manual operation, it has been reported that the efficiency of practice decreases due to the error between the block position and the attack position. Therefore, in order to operate the block machine automatically, we propose a method to acquire the player position from monocular video in real time and predict the attack position.

This paper presents a system that consists of three robots to imitate the motion of top volleyball blockers. In a volleyball match, in order to score by spiking, it is essential to improve the spike decision rate of each spiker. To increase the spike decision rates, iterative spiking training with actual blockers is required. Therefore, in this study, a block machine system was developed that can be continuously used in an actual practice field to improve attack practice. In order to achieve the required operating speed and mechanical strength each robot has five degrees of freedom. This robot performs high speed movement on 9 m rails that are arranged in parallel with the volleyball net. In addition, an application with a graphical user interface to enable a coach to manipulate these robots was developed. It enables the coach to control block motions and change the parameters such as the robots' positions and operation timing. Through practical use in the practice field, the effectiveness of this system was confirmed.

In this study, a haptic rendering method named indirect haptic feedback is proposed. In traditional haptic interfaces for the index finger, the contact point of the finger and the point of application of force are the same when touching a virtual object. As a result, in the augmented reality environment, a user is unable to touch a real object with his/her bare hand through traditional haptic interfaces. In this study, separate contact and reaction force points are selected for haptic rendering. To realize this, a prototype system, which consists of a motion tracker, a 2-DOF haptic interface that is equipped with a force sensor, and a visual display, is developed. The system measures the position of the fingertip of a user and produces an appropriate horizontal force on the thenar eminence (the group of muscles on the palm of the human hand at the base of the thumb) of the user. Through the visio-haptic interface, a user can perceive the surfaces of 3D virtual objects. In addition, the user can perceive the frictional force on the surface of the objects. Through two evaluation tests, it was verified that the subjects could effectively perceive the 3D virtual objects using this system.

Various systems for hand tool skill training have been developed in the domain of haptic displays. These systems typically present force to a learner's palm by directly actuating the tool. However, this approach is sometimes ineffective because learners have difficulty sensing the haptic feedback from the tool when they are holding it tightly. Thus, we propose a different approach (OCHD) that effectively guides the learner's hand by presenting force to the back of his/her hand as if an instructor is holding it. A preliminary experiment showed that OCHD effectively guides users with less actuator drive force than cases where the tool is directly actuated.

CirculaFloor is a locomotion interface that uses a set of movable tiles. The movable tiles employ a holonomic mechanism that achieves omni-directional motion. Circulation of the tiles enables the user to walk in a virtual environment while his/her position is maintained. The user can walk in any chosen direction in the virtual environment. A prototype is implemented and its performance is evaluated thorough video analysis of mass participants and physical measurement of the walker.

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.

Abstract 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 © 2003 John Wiley & Sons, Ltd.

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.

Describes the design and implementation of an artificial force display for immersive projection displays (IPD) such as CAVE or CABIN. In order to give the user maximum freedom of motion in the large virtual space generated by an IPD, it is necessary to use a portable force display that is self-contained on the user's body. Therefore, we developed a wearable force display called HapticGEAR. It is a backpack-type device that transmits applied forces to the wearer by using a wire-tension mechanism. The device is designed such that it minimizes fatigue for the wearer and does not interrupt the user's motion and view. Also, we integrated the device into CABIN and experimentally evaluated both the accuracy it achieved in tracing objects and the displayed haptic sensation.

The Gait Master is a locomotion interface that creates a sense of walking on an uneven surface. The device employs a turntable on which two motion platforms (one for each foot) are mounted. The motion platforms track the feet and carry them back to their neutral position. The user can physically walk in a virtual space while their position is maintained. The motion platforms move vertically, which simulates an uneven surface. The walker can climb up or go down a virtual staircase while their position is maintained. The turntable rotates the two motion platforms, so that the walker can walk in any direction. We have developed two prototypes and have evaluated them through user studies.

By sharing data regarding the sensations experienced by individuals, as well as by sharing their knowledge, we are readily able to communicate with each other, and there are possibilities to further evolve this communication method. The different sensations experienced during voluntary walking and enforced walking give us different feelings. Also, the number of individuals involved can create a different feeling when walking. Networked computer-assisted walking can support and enhance these different experiences. In this paper, we introduce another walking style, the shared power-assisted voluntary walk, which is realized by a prototype networked locomotion system. This system can be used in tele-rehabilitation, which allows remote patients to share the sensation of walking. Also, it can be used to teach a group of patients rehabilitative walking. We developed two locomotion interfaces and connected them via a network. We developed enforced and semi-voluntary walking training systems using the shared walk environment and evaluated them with a series of experiments. operation integration process. In the second algorithm, thanks to deferred broadcast of operations to other sites, this process becomes even more simplified.

We describe the design and the implementation of a force display for immersive projection displays. To give the user maximum freedom of motion in a large working space, it is necessary to use a portable force display that is grounded on the user's body. Therefore, we developed a portable (wearable) force display called HapticGEAR which makes use of the tension of wires grounded on the user's back. This device is designed to reduce user's fatigue and to have fewer influence on the user's motion and sight.

This paper describes the design philosophy and the experimental results of the optical submarine repeater for the OS-280M optical fiber submarine cable system to be installed across the ocean. This repeater which employs the information rate of 280 Mbit/s, the optical wavelength of 1.3 μm, and is implemented with monolithic IC's, features high reliability, long repeater spans, and the supervisory systems. The test results show that the average optical output power is - 1.4 dBm for the mark density of 1/2, the minimum average power of the optical input for the BER 10 is about -38 dBm at the room temperature, and other specifications are also well satisfied.