Hiroyuki Kajimoto

Hiroyuki Kajimoto
The University of Electro-Communications | UEC · Department of Informatics

About

353
Publications
28,457
Reads
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3,534
Citations
Citations since 2016
164 Research Items
2184 Citations
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20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400

Publications

Publications (353)
Article
Full-text available
Various methods for inducing an illusory force sensation to present a sense of force to users in energy-saving and space-saving systems have been proposed. One of them is the illusion of force sensation induced by cutaneous sensory stimulation. In this study, we hypothesized and empirically verified that lateral skin stretch alone on the face can i...
Article
Full-text available
To enrich the virtual reality experience and improve realism, many studies have proposed embedding tactile devices into head-mounted displays (HMDs). However, although thermal and vibrotactile cues have become commonplace, presentation of the constant pressure necessary for softness expression remains relatively rare. In this study, we propose a su...
Chapter
Full-text available
Electrical stimulation is one of the methods to stimulate skin sensation, and can provide sensations such as vibration and pressure by changing the polarity of the stimulus. These stimuli can be combined to design a variety of tactile sensations. However, there is a major problem with electrical stimulation: As the amount of electric current is inc...
Chapter
Full-text available
When an object that is grasped with a finger is pulled by an external force, the traction force is perceived by cutaneous receptors and proprioception in the finger. Several attempts have been made to simulate the pulling sensation by using wearable devices, including mechanical asymmetric vibration and tightening by belt. In this study, we develop...
Chapter
Full-text available
We proposed to use kinesthetic illusion to achieve wearable/portable haptic devices for kinesthetic feedback in VR experiences. The kinesthetic illusion is the illusion of limb movement typically induced by vibratory stimulation. We investigated how the kinesthetic illusion affected the perceived weight and resistance of the handheld object. We des...
Article
Full-text available
Several existing haptic displays used in virtual reality (VR) environments present haptic sensations generated by the fingertips in the VR to actual fingertips. However, these devices face certain challenges, such as physical interference between the devices, particularly when multi-degree-of-freedom (DOF) force needs to be presented to multiple fi...
Article
Full-text available
One of the important challenges in the field of haptic engineering is the development of methods to present haptic information on commonly-used information devices equipped only with screens and speakers. Earlier research has proposed the so-called “pseudo-haptic” method that can give users haptic impressions by modulating the visual feedback provi...
Article
Full-text available
Many wearable interfaces have been proposed to present force to the upper limb and elbow joint. One way to achieve a compact wearable haptic interface is to use electrical stimulation, and we have suggested that transcutaneous electrical stimulation above the wrist tendon can produce force a sensation in the direction of the muscle stretching; howe...
Article
Full-text available
Unlike tactile displays that use mechanical actuators, electrode-type tactile displays can be easily integrated and miniaturized because they consist of electrodes and insulators. Electrical tactile displays only require electrodes and use an electric current to stimulate vibration or pressure. Likewise, electrostatic friction tactile displays also...
Article
Full-text available
Human fingertips are densely populated with tactile receptors and are hence incredibly sensitive. However, wearing gloves on the fingers drastically reduces the tactile information available to the fingertips, such as the texture and shape of the object, and makes it difficult to perform dexterous work. As a solution, in this study, we developed a...
Article
The stick-slip phenomenon occurs in dynamic friction plays an important role in haptic perception. We observed that when using the finger pad to interact with a rough surface, under a certain downforce, the stick-slip phenomenon is more likely to occur when the finger exploring in ulnar direction than radial direction. We speculated that this might...
Article
In recent years, many researchers have been investigating the addition of other modalities such as haptics to the visual and auditory based VR experience using HMDs. On the other hand, these haptic devices are cumbersome to wear and their fingers cannot be moved freely. We solved these problems by embedding a suction tactile presentation device in...
Article
The purpose of this study was to investigate whether stimulation of the proprioceptors in the arm during active movement can affect not only the proprioception of the arm but also the perception of the hand-held object. If it is possible to control the perception of a hand-held object through stimulation to the body, it can be applied to virtual-re...
Article
Along with spread of low-cost HMD and high-quality VR experience, many proposals have been made to improve the VR experience by providing tactile information to the fingertips. However, attaching and detaching a device is difficult and the movement of the finger are limited. In order to solve these problems, we have proposed Haptopus that incorpora...
Article
Presenting kinesthetic sensation usually requires a large space so as to avoid users colliding with objects or other users. One way to tackle this issue to use kinesthetic illusion, which is a way of presenting kinesthetic sensation without physical motion. However, realizing dynamic motion and fast movement remains difficult. Considering that mult...
Article
Small devices that present a tactile sensation and can easily be mounted on skin have been proposed by attaching a magnet to a fingertip and setting a remote driving coil on the environment side. However, such devices have been used only at a distance of several centimeters from the coil. We show that a coil of practical size and power consumption...
Article
In the present virtual reality systems, because users must move their physical body, there are problems in safety, cost and accessibility. In order to solve these problems, we have proposed a system that creates sense of movement without physical movement of user’s body using kinesthetic illusion induced by tendon vibration. In this paper, we condu...
Article
We have attempted to reproduce the texture of several artificial skins by displaying horizontal vibrations and lateral forces based on recordings of the vibrations and friction generated when a finger traces these artificial skins. Our main idea was to ensure the softness and viscoelasticity of the artificial skin through use of a real smooth skin...
Article
We have proposed a grounded haptic display that can widely present the force sensation using fishing rod. The display incorporates a fishing rod to present the force sensation at the user’s fingertip using a thread being reeled from the tip of the fishing rod. This device requires conversion from the position of the user’s fingertip and magnitude o...
Article
The gap detection threshold is an index of spatial resolution at the fingertip. This threshold value has been measured only on a flat plate such as an iron plate, and it has hardly been measured on a rough surface such as a rough surface. This paper describes how the gap perception threshold changes when the surface roughness of an object is change...
Article
The purpose of our research is to develop an electrostatic tactile graphics display for visually impaired to read figures. We have evaluated our tactile graphics system that displays a tactile sensation based on a user’s single finger movement. However, the result showed that it was difficult for the user to capture the shapes of figures correctly....
Article
We propose a tactile display with high intensity using many small vibrators suitable for mounting. At this time, it is necessary to know the details of the relation between the presentation area which changes by the number of vibrators, the actual perception area, and the subjective intensity. In this study, we measure changes in subjective intensi...
Article
This paper investigated the difference on the effect of the knee Hanger-Reflex by simultaneously measuring the skin stretch and the pressure distribution. The measured data was analyzed by the weighted average, and two pressure peak positions were obtained. This result shows the same tendency observed at the other body parts. From the skin shear di...
Article
Full-text available
The hanger reflex is a phenomenon characterized by the involuntary rotation of the head when a wire hanger is worn around the head such that a force is applied to the frontal temporal area by the longer side of the hanger. The application of a shearing force on the skin is thought to be the cause of this phenomenon. Attempts have been made to treat...
Chapter
Full-text available
We present ElectroAR, a visual and tactile sharing system for hand skills training. This system comprises a head-mounted display (HMD), two cameras, a tactile sensing glove, and an electro-tactile stimulation glove. The trainee wears the tactile sensing glove that gets pressure data from touching different objects. His/her movements are recorded by...
Chapter
Full-text available
This paper proposes a grounded haptic display that can widely present a force sensation using a fishing rod. The proposed haptic display incorporates a fishing rod to present the force sensation at the user’s fingertip using a thread being reeled from the tip of the fishing rod. The multidirectional force sensation is presented by driving the base...
Chapter
Full-text available
In current virtual reality (VR) systems, the physical movement of the body is required, which creates problems of safety, cost, and accessibility. To solve those problems, we propose a system that fixes a user’s body, detects force when a user tries to move, and generates the sensation of movement using kinesthetic illusion caused by tendon vibrati...
Chapter
Full-text available
Kinesthetic sensation is important for improving presence and immersion in VR environments. However, presenting kinesthetic sensation usually requires a large space so as to avoid users colliding with objects or other users. One of the ways to tackle this issue is to use kinesthetic illusion, which is a way of presenting kinesthetic sensation witho...
Chapter
Full-text available
In the field of tactile displays, electrostatic force displays have been developed for presenting tactile stimulation on a screen. However, with the conventional electrostatic force displays, the user cannot feel the stimulation without rubbing on the display. In this paper, to solve this problem, we propose a new method to present a tactile sensat...
Preprint
Full-text available
We present ElectroAR, a visual and tactile sharing system for hand skills training. This system comprises a head-mounted display (HMD), two cameras, tactile sensing glove, and electro-stimulation glove. The trainee wears a tactile sensing glove that gets pressure data from touching different objects. His movements are recorded by two cameras, which...
Article
Full-text available
Understanding the relationship between the displacement of the skin when tracing a textured object and the resulting subjective sensations is essential in designing tactile displays. Previous studies observed skin displacement using flat glass plates or uneven surfaces that do not optically interfere with finger surface observations. In contrast, n...
Article
Full-text available
The use of real textures is the optimal way to present realistic textures in a VR (Virtual Reality) experience. However, a system may require the presentation of numerous objects in a VR scene, making the use of real objects impractical. One way to address this issue is to present visual and tactile texture information simultaneously such that mult...
Preprint
Full-text available
For the human operator, it is often easier and faster to catch a small size quadrotor right in the midair instead of landing it on a surface. However, interaction strategies for such cases have not yet been considered properly, especially when more than one drone has to be landed at the same time. In this paper, we propose a novel interaction strat...
Article
As a method of imparting a tactile sense to the VR experience, a method has been proposed in which the experiencer actually touches an object of the same material as the object visually displayed in the VR space. However, with this method, it is necessary to prepare the same number of objects as the type of the object in the VR space.In this resear...
Article
In this study, we aim to present various skin condition with haptic display. We record the acceleration when a finger swipes on the skin, and replay it as vibration. The replaying part is composed of an artificial skin, two audio speakers to vibrate the skin horizontally, and a motion capture system to monitor finger motion. Our idea is that we ass...
Article
To reproduce realistic tactile sensations on a tactile display, it is important to elucidate the relationship between skin deformation and tactile sensations. For this purpose, we previously proposed a device to measure 3-dimensional skin deformation but it was not evaluated using actual skin. In this study, we improved the device to address the is...
Article
The visually impaired have to obtain shape information through tactile graphics. We have developed a tactile graphics recognition system with electrostatic tactile display, and have investigated recognition rates of displayed figures in our previous research. Based on the result, we improved the rendering methods. In this paper, we conducted a pilo...
Article
Hanger-reflex is a phenomenon in which a sense of rotation and haptic force are caused by attaching a wire hanger to the head. In previous studies, we confirmed the occurrence of this phenomena in the head, lumbar region and wrist, but strong expression was not confirmed in the feet. In this paper, we investigated the conditions that efficiently an...
Preprint
Full-text available
We propose a novel system SwarmCloak for landing of a fleet of four flying robots on the human arms using light-sensitive landing pads with vibrotactile feedback. We developed two types of wearable tactile displays with vibromotors which are activated by the light emitted from the LED array at the bottom of quadcopters. In a user study, participant...
Conference Paper
Full-text available
We propose a novel system SwarmCloak for landing of a fleet of four flying robots on the human arms using light-sensitive landing pads with vibrotactile feedback. We developed two types of wearable tactile displays with vibromotors which are activated by the light emitted from the LED array at the bottom of quadcopters. In a user study, participant...
Conference Paper
We developed a high-density tactile vest that presents the haptic sensation of the five fingertips to the back rather than to the fingertip as a new haptic presentation method for objects in a virtual reality (VR) environment. The device adopts 144 eccentric mass vibration motors actuated individually and five Peltier elements. The voice coils pres...
Conference Paper
In recent years, self-balancing transporters have become popular for medium-distance transportation such as police patrols and sightseeing tours, and are expected to further gain prevalence. Therefore, it is important to develop danger avoidance and automated driving systems for self-balancing transporters. However, automated control of a self-bala...
Conference Paper
We developed The “Hapballoon”, a novel device that is worn on the fingertips. The device can present three types of sensations: force, warmth, and vibration. Force sensations are presented when the inflated balloons on individual devices contact one another. The device is easy to attach on the finger, and does not obstruct common optical finger tra...
Conference Paper
The kinesthetic sensation is important in terms of creating presence in virtual reality applications. One possible way of presenting the kinesthetic sensation with compact equipment is to use the kinesthetic illusion, which is an illusion of position and movement of the one’s own body, generated by vibration. However, the kinesthetic illusion obser...
Conference Paper
Naturalistic tactile sensations can be elicited by mechanical stimuli because mechanical stimulations reproduce natural physical phenomena. However, a mechanical stimulation that is too strong may cause injury. Although electrical stimulation can elicit strong tactile sensations without damaging the skin, it is inferior in terms of naturalness. We...
Article
Full-text available
The quantification of stickiness experienced upon touching a sticky or adhesive substance has attracted intense research attention, particularly for application to haptics, virtual reality, and human–computer interactions. Here, we develop and evaluate a device that quantifies the feeling of stickiness experienced upon touching an adhesive substanc...
Article
Vibrotactile and friction texture displays are good options for artificially presenting the roughness and frictional properties of textures, respectively. These two types of displays are compatible with touch panels and exhibit complementary characteristics. We combine vibrotactile and electrostatic friction texture displays to improve the quality...
Article
Full-text available
The objective of this study is to test the feasibility of a semi-automated scoring system for the Toronto Western Spasmodic Torticollis Scale (TWSTRS) severity scale in patients with cervical dystonia. The TWSTRS requires training and experience. We previously developed a system to measure neck angle by analyzing three-dimensional position, obtaine...
Conference Paper
The Ouija board game is associated with a type of involuntary motion known as an ideomotor action. We sought to clarify the conditions under which this motion occurs by evaluating the effect that visual and haptic movement cues have on its occurrence. Using our lateral skin deformation device, we found that the simultaneous presentation of visual a...
Chapter
The visually impaired must obtain shape information in a tactile manner. However, existing conventional graphics are static. We prepared a more useful, dynamic tactile display; we aimed to allow the visually impaired to recognize and draw figures via tactile feedback. We developed an electrostatic force-based tactile display and performed two preli...
Chapter
Full-text available
This paper introduces a system of tactile transmission on the fingertips in which there are two sides: tactile-sender and a tactile-receiver. For the tactile-sender side, we developed a tactile sensor array and attached it inside a glove. This tactile sensor can simultaneously measure the temperature and the pressure distribution by measuring the r...
Chapter
We developed a 3D virtual reality system with electro-tactile and pseudo force stimulation for presenting sensation of shape and stiffness of an object to the tips of thumb and index finger. Our system comprises two fingertip gloves and a finger-motion capture device. Each glove provides a shape sensation via an electrode array of the electro-tacti...
Chapter
Touch screens used as interfaces rarely give tactile feedback to users. We developed a electrostatic-force-based tactile display, however, it cannot express softness feelings on the screen. In this research, we attempted to display softness feeling by using multi-electrodes and a pressure sensor. When using our system, we observed that the user can...